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1

IMPROVED SEA URCHIN DNA-BASED EMBRYO GROWTH TOXICITY TEST  

EPA Science Inventory

The article presents an improved DNA-based embryo toxicity test in which growth is measured as the increase in DNA during a 5-h postfertilization period. The test, using direct fluorometric determination of DNA rather than thymidine incorporation, is fast, sensitive, easy to cond...

2

Partiton-controlled delivery of toxicants: a novel in vivo approach for embryo toxicity testing.  

PubMed

In conventional static or semi-static embryo toxicity assays with fish, the nominal concentrations of hydrophobic chemicals are often used to establish the toxic thresholds, which often far exceed the solubility limits of test compounds. Saturators and continuous-flow diluters have been used to provide stable concentrations below solubility but are complex, use large amounts of test substance, and produce large volumes of waste. We present a partition-controlled delivery (PCD) method that maintains the concentrations of chemicals in test solutions at or below solubility limits for extended exposure times. Concentrations are maintained by equilibrium partitioning of test chemicals from a series of poly(dimethylsiloxane) films loaded with a range of concentrations of each chemical. The efficacy of the PCD assay was tested by comparisons with static (no renewal) and semi-static (24-h renewal) embryo-larval toxicity tests. The test species was Japanese medaka (Oryzias latipes) exposed to retene (7-isopropyl-1-methylphenanthrene), a compound causing blue sac disease (BSD) in fish embryos. In the PCD assay, the median effective concentration (EC50) for BSD was 10 microg/L, below retene's solubility of 17 microg/L. In contrast, the nominal EC50 values for the semi-static 24-h and static assays were about 10 (150 microg/L) and 150 times (2500 microg/L) greater than solubility, respectively. The PCD method is a more sensitive and realistic method for assessing toxicity of nonpolar compounds than (semi)-static assays. PMID:12785534

Kiparissis, Yiannis; Akhtar, Parveen; Hodson, Peter V; Brown, R Stephen

2003-05-15

3

COMPARATIVE EVALUATION OF THREE RAPID MARINE TOXICITY TESTS: SEA URCHIN EARLY EMBRYO GROWTH TEST, SEA URCHIN SPERM CELL TOXICITY TEST AND MICROTOX  

EPA Science Inventory

Three rapid marine toxicity tests were evaluated to determine their potential usefulness in a toxicity testing program: early embryo growth test and sperm cell toxicity test, both using the sea urchin Arbacia punctulata, and Microtox. Toxicity values (EC50s) were derived for eigh...

4

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...

5

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...

6

Is the fish embryo toxicity test (FET) with the zebrafish (Danio rerio) a potential alternative for the fish acute toxicity test?  

PubMed

The fish acute toxicity test is a mandatory component in the base set of data requirements for ecotoxicity testing. The fish acute toxicity test is not compatible with most current animal welfare legislation because mortality is the primary endpoint and it is often hypothesized that fish suffer distress and perhaps pain. Animal alternative considerations have also been incorporated into new European REACH regulations through strong advocacy for the reduction of testing with live animals. One of the most promising alternative approaches to classical acute fish toxicity testing with live fish is the fish embryo toxicity (FET) test. The FET has been a mandatory component in routine whole effluent testing in Germany since 2005 and has already been standardized at the international level. In order to analyze the applicability of the FET also in chemical testing, a comparative re-evaluation of both fish and fish embryo toxicity data was carried out for a total of 143 substances, and statistical approaches were developed to evaluate the correlation between fish and fish embryo toxicity data. Results confirm that fish embryo tests are neither better nor worse than acute fish toxicity tests and provide strong scientific support for the FET as a surrogate for the acute fish toxicity test. PMID:19095081

Lammer, E; Carr, G J; Wendler, K; Rawlings, J M; Belanger, S E; Braunbeck, Th

2009-03-01

7

SIMPLE TEST FOR TOXICITY OF NUMBER 2 FUEL OIL AND OIL DISPERSANTS TO EMBRYOS OF GRASS SHRIMP, PALAEMONETES PUGIO  

EPA Science Inventory

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 ad...

8

A microscale test to measure petroleum oil toxicity to mummichog embryos.  

PubMed

A test was developed to compare the toxicity of different petroleum oils to mummichog (Fundulus heteroclitus) embryos. Fertilized eggs were incubated for 11 days at 22.5 degrees C directly on the surface of oil-contaminated sand without a superficial water layer. The mortality rates, the stage of development, and the prevalence of malformations were determined. No effect was found in controls incubated on sand with water and mineral oil as compared with controls on sand with water alone. Two weathered oils, an Alaska North Slope crude oil (ANCO) and a Mesa light crude oil (MLCO), produced similar symptoms of toxicity: retarded growth and development, pericardial edema, hemostasis, hemorrhages, and spinal deformities. These symptoms are consistent with those observed in other fish species exposed to petroleum oils, suggesting that the results of the bioassay would be applicable to other species. MLCO was more embryotoxic than ANCO. The minimal oil concentrations causing a significant reduction in body length were 4.5 microg oil/g sand for MLCO and 12.7 microg oil/g for ANCO, indicating the assay is sensitive. The slopes and the intercepts of the relationships between concentration and growth did not differ in three dose-response experiments conducted with each oil, indicating that the assay is reliable. Finally, the bioassay is less costly than other available options to assess the toxicity of petroleum oils to marine fish embryos. Further work to improve the standardization of the assay will involve comparison of the toxicity of petroleum oils with reference toxicants and selection of a standard substrate. PMID:12112627

Couillard, C M

2002-01-01

9

Large-Scale Assessment of the Zebrafish Embryo as a Possible Predictive Model in Toxicity Testing  

PubMed Central

Background In the drug discovery pipeline, safety pharmacology is a major issue. The zebrafish has been proposed as a model that can bridge the gap in this field between cell assays (which are cost-effective, but low in data content) and rodent assays (which are high in data content, but less cost-efficient). However, zebrafish assays are only likely to be useful if they can be shown to have high predictive power. We examined this issue by assaying 60 water-soluble compounds representing a range of chemical classes and toxicological mechanisms. Methodology/Principal Findings Over 20,000 wild-type zebrafish embryos (including controls) were cultured individually in defined buffer in 96-well plates. Embryos were exposed for a 96 hour period starting at 24 hours post fertilization. A logarithmic concentration series was used for range-finding, followed by a narrower geometric series for LC50 determination. Zebrafish embryo LC50 (log mmol/L), and published data on rodent LD50 (log mmol/kg), were found to be strongly correlated (using Kendall's rank correlation tau and Pearson's product-moment correlation). The slope of the regression line for the full set of compounds was 0.73403. However, we found that the slope was strongly influenced by compound class. Thus, while most compounds had a similar toxicity level in both species, some compounds were markedly more toxic in zebrafish than in rodents, or vice versa. Conclusions For the substances examined here, in aggregate, the zebrafish embryo model has good predictivity for toxicity in rodents. However, the correlation between zebrafish and rodent toxicity varies considerably between individual compounds and compound class. We discuss the strengths and limitations of the zebrafish model in light of these findings. PMID:21738604

Ali, Shaukat; van Mil, Harald G. J.; Richardson, Michael K.

2011-01-01

10

Fish embryo toxicity of carbamazepine, diclofenac and metoprolol  

Microsoft Academic Search

Frequently measured pharmaceuticals in environmental samples were tested in fish embryo toxicity (FET) tests with Danio rerio, based on the draft OECD test protocol. In this FET test 2-h-old zebrafish embryos were exposed for 72h to carbamazepine, diclofenac and metoprolol to observe effects on embryo mortality, gastrulation, somite formation, tail movement and detachment, pigmentation, heartbeat, malformation of head, otoliths and

Evert-Jan van den Brandhof; Mark Montforts

2010-01-01

11

Development of a flow-through system for the fish embryo toxicity test (FET) with the zebrafish (Danio rerio).  

PubMed

The acute fish test is still a mandatory component in chemical hazard and risk assessment. However, one of the objectives of the new European chemicals policy (REACH - Registration, Evaluation, Authorization and Restriction of Chemicals) is to promote non-animal testing. For whole effluent testing in Germany, the fish embryo toxicity test (FET) with the zebrafish (Danio rerio) has been an accepted and mandatory replacement of the fish test since January 2005. For chemical testing, however, further optimization of the FET is required to improve the correlation between the acute fish test and the alternative FET. Since adsorption of the test chemical to surfaces may reduce available exposure concentrations, a flow-through system for the FET using modified commercially available polystyrene 24-well microtiter plates was developed, thus combining the advantages of the standard FET with those of continuous delivery of test substances. The advantages of the design presented include: small test footprint, availability of adequate volumes of test solution for subsequent chemical analysis, and sufficient flow to compensate for effects of non-specific adsorption within 24h. The flow-through test system can also be utilized to conduct longer-term embryo larval fish tests, thus offering the possibility for teratogenicity testing. PMID:19486937

Lammer, E; Kamp, H G; Hisgen, V; Koch, M; Reinhard, D; Salinas, E R; Wendler, K; Zok, S; Braunbeck, Th

2009-10-01

12

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 ...

13

Solitary ascidians embryos (Chordata, Tunicata) as model organisms for testing coastal pollutant toxicity  

Microsoft Academic Search

Marine coastal communities are daily exposed to several chemical compounds commonly used in agriculture and industrial activities. Therefore, toxicological studies evaluating the effects of these compounds on marine organisms are of primary importance for marine environment preservation. Different model organisms are used to perform toxicity tests with potential pollutants, under laboratory conditions. In last decades, solitary ascidians have been selected

G Zega; R Pennati; S Candiani; M Pestarino; F De Bernardi

2009-01-01

14

Toxic and teratogenic effects of selected aromatic amines on embryos of the amphibian Xenopus laevis  

Microsoft Academic Search

Evaluations of the toxic and teratogenic effects of four aromatic amines, acridine, aniline, pyridine, and quinoline, have been made on amphibian (Xenopus laevis) embryos. For toxicity testing, the embryos were divided into three groups according to stage of development: Group I were mid-blastulae, Group II were tailbud embryos, and Group III were swimming larvae. Of the amines tested, acridine and

Keith R. Davis; T. Wayne Schultz; James N. Dumont

1981-01-01

15

Toxicity of Trihalomethanes to Common Carp Embryos  

Microsoft Academic Search

Trihalomethanes recently have been identified in real and simulated effluents from power plants where chlorine is used for biofouling control. Toxicity of the four chlorine- or bromine-containing trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) to developing common carp (Cyprinus carpio) embryos was determined under conditions of intermittent (8-hour) toxicant renewal, based on percent hatch as the end point. Nominal median lethal

J. S. Mattice; S. C. Tsai; M. B. Burch; J. J. Beauchamp

1981-01-01

16

Toxicity of trihalomethanes to common carp embryos  

Microsoft Academic Search

Trihalomethanes recently have been identified in real and simulated effluents from power plants where chlorine is used for biofouling control. Toxicity of the four chlorine- or bromine-containing trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) to developing common carp (Cyprinus carpio) embryos was determined under conditions of intermittent (8-hour) toxicant renewal, based on percent hatch as the end point. Nominal median lethal

J. S. Mattice; S. C. Tsai; M. B. Burch; J. J. Beauchamp

1981-01-01

17

Toxicity of chlorine to zebrafish embryos  

PubMed Central

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 – 50 ppm unbuffered chlorine solution for 5 – 10 min. Treatment of embryos with chlorine has significant germicidal effects for many Gram-negative bacteria, viruses, and trophozoite stages of protozoa, it has reduced efficacy against cyst or spore stages of protozoa and certain Mycobacterium spp. Therefore, we evaluated the toxicity of unbufferred and buffered chlorine solution to embryos exposed at 6 or 24 hours post-fertilization (hpf) to determine if 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 pHs, and chlorine causes elevated pH. Consistent with this, we found that unbufferred 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 for 5 min with unbuffered chlorine solution at 100 ppm. One trial indicated that AB fish, a popular outbred line, are more susceptible to toxicity than 5Ds. This suggests that variability between zebrafish lines occurs, and researchers should evaluate each line or strain under their particular laboratory conditions for selection of the optimum chlorine treatment procedure. PMID:24429474

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

2014-01-01

18

Toxicity of 15 veterinary pharmaceuticals in zebrafish (Danio rerio) embryos.  

PubMed

Extensive use of veterinary pharmaceuticals may result in contamination of water bodies adjacent to pasture land or areas where animal manure has been applied. In order to evaluate the potential risk to fish embryos 15 veterinary pharmaceuticals were investigated by use of an extended zebrafish embryo toxicity test. Chemical analysis of the exposure medium was performed by solid phase extraction-liquid chromatography-tandem mass spectrometry (SPE-LC-MS/MS) for 11 of the compounds and potential metabolism by the embryos was studied for albendazole, febantel, fenbendazole and oxfendazole. Newly fertilized zebrafish eggs were exposed under static conditions in 96-well plates for 6 days to the pharmaceuticals: 5 antibacterials and 10 antiparasitics. Endpoints including mortality, malformations and other sublethal responses were recorded at 24, 48 and 144 h post fertilization (hpf). The pharmaceuticals causing the highest toxicity were antiparasitics whereas the tested antibacterials, danofloxacin, enrofloxacin, tylosine, trimethoprim and oxytetracyclin had a much lower toxic potency in zebrafish embryos. Most toxic were fenbendazole, albendazole and flumethrin with no observed effect concentrations (NOECs) around 0.02 mg/L. The overall NOEC was determined by lethality for the following pharmaceuticals: albendazole, fenbendazole and oxfendazole. Sublethal endpoints, including malformations, side-laying embryos, tremors, reduced movements and altered heart rate increased the sensitivity of the tests and determined the overall NOECs for febantel, doramectin, ivermectin, flumethrin and toltrazuril. Exposure to doramectin and ivermectin caused a decrease in movements at 24 hpf and a decrease in heart rate at 48 hpf. Flumethrin exposure resulted in decreased time to hatching, except at the highest concentrations, and caused an increase in heart rate at 48 hpf. In contrast, toltrazuril caused an increased time to hatching and a decrease in heart rate. Chemical analysis of the exposure medium after the tests revealed great differences between nominal and measured concentrations, emphasizing the need of including analysis of the actual exposure concentrations. The results indicated that metabolism of albendazole into its sulfoxide protected the embryos from toxicity. Albendazole was metabolized efficiently into albendazole sulfoxide at lower exposure concentrations, resulting in reduced toxicity. At higher concentrations, an increasing proportion of albendazole remained unmetabolized and embryo mortality occurred. Metabolism by the embryos of febantel into fenbendazole and oxfendazole and of fenbendazole into oxfendazole was demonstrated. It is suggested that the toxic effect of febantel in zebrafish embryos is due to metabolism into fenbendazole. PMID:23142600

Carlsson, Gunnar; Patring, Johan; Kreuger, Jenny; Norrgren, Leif; Oskarsson, Agneta

2013-01-15

19

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

PubMed

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. PMID:24929227

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

2014-08-01

20

Toxic effects of colloidal nanosilver in zebrafish embryos.  

PubMed

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. PMID:24395442

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

2014-05-01

21

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

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.

Jong, Esther de, E-mail: Esther.de.Jong@rivm.nl [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Barenys, Marta [GRET-CERETOX, Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona, Barcelona (Spain); Hermsen, Sanne A.B. [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Department of Health Risk Analysis and Toxicology, NUTRIM, University of Maastricht, Maastricht (Netherlands); Verhoef, Aart [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Ossendorp, Bernadette C.; Bessems, Jos G.M. [Centre for Substances and Integrated Risk Assessment, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H. [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands)

2011-06-01

22

Toxicity of trihalomethanes to common carp embryos  

SciTech Connect

Trihalomethanes recently have been identified in real and simulated effluents from power plants where chlorine is used for biofouling control. Toxicity of the four chlorine- or bromine-containing trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) to developing common carp (Cyprinus carpio) embryos was determined under conditions of intermittent (8-hour) toxicant renewal, based on percent hatch as the end point. Nominal median lethal concentrations (LC50) ranged from 161 mg/liter for chloroform to 53 mg/liter for dibromochloromethane. Decay studies conducted under conditions similar to those used for the toxicity studies, but in distilled water, indicated that (1) half-lives of the trihalomethanes ranged from 4.4 to 6.9 hours; (2) decay was due primarily to volatilization; (3) higher relative toxicity of dibromochloromethane probably was due to formation of a degradation product (likely Br/sub 2/). Correction of the nominal LC50 values to time-weighted mean concentrations over the period between toxicant changes gave weighted LC50 values of 97.2, 67.4, 33.5, and 52.3 mg/liter for chloroform, bromodichloromethane, dibromochloromethane, and bromoform, respectively. In addition, the period of water-hardening of fertilized eggs was not critical for expression of toxicity of dibromochloromethane. Comparison of these and other published data on effluent and toxic concentrations, persistence, and bioaccumulation of water-chlorination products suggests that trihalomethanes are not as environmentally critical as other chlorinated organic compounds or residual chlorine.

Mattice, J.S. (Oak Ridge National Lab., TN); Tsai, S.C.; Burch, M.B.; Beauchamp, J.J.

1981-03-01

23

Evaluation of acute toxicity and teratogenic effects of plant growth regulators by Daphnia magna embryo assay.  

PubMed

This study selected common plant growth regulators (Atonik, Cytokinin, Ethephon, Gibberellic acid and Paclobutrazol) to investigate their biological toxicity to the waters of the important biological indicator Daphnia magna. The methods used in this study included traditional neonate acute toxicity test, new Daphnia embryo toxicity test, and teratogenic embryo test. The study concluded that the acute toxicity of the five PGRs to Daphnia neonate had EC(50) value range of 1.9-130.5 mg l(-1), while acute toxicity of PGRs on Daphnia embryo had EC(50) value range of 0.2-125 mg l(-1); the Daphnia embryos' LOEC values (0.05-48 mg l(-1)) for the five PGRs were lower than embryo EC(50) values. The toxic ratios of 48 h EC(50) (neonate)/48 h LOEC (embryo) for 5 PGRs were 19-512 times. The study found that teratogenic effects of Paclobutrazol and Cytokinin induced in embryo were higher than those of most other PGRs. Microscopic observation of the teratogenic effects showed that all 5 PGRs induced malformations of the second antenna, rostrum, Malpighian tube, sensory bristles, and tail spine as well as function loss and death. PMID:21514995

Wang, Kai-Sung; Lu, Chi-Yuan; Chang, Shih-Hsien

2011-06-15

24

Toxic Effects of Silica Nanoparticles on Zebrafish Embryos and Larvae  

PubMed Central

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

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

2013-01-01

25

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

NASA Astrophysics Data System (ADS)

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.

Yang, Zhihui; Zhang, Xiangjing; Cai, Zhonghua

2009-05-01

26

Toxicity of cryoprotectants agents in freshwater prawn embryos of Macrobrachium amazonicum.  

PubMed

Summary The process of cooling and cryopreservation of prawn embryos is a viable alternative for a continuous supply of larvae for freshwater prawn farming ponds. However, studies involving the application of those techniques as well as on toxicity of cryoprotectants in freshwater prawn embryos are scarce. Thus, this study aims to test the toxicity of methylic alcohol (MET), dimethyl sulfoxide (DMSO) and ethylene glycol (EG) on Macrobrachium amazonicum embryos. For the present experiment, pools of embryos were taken from 15 M. amazonicum females and were divided into three groups and tested in duplicate at concentrations of 10, 5, 3; 1, 0.5 or 0.1%. Toxicity tests were conducted for 24 h in Falcon® pipes to obtain the lethal concentration for 50% of the larvae (LC50). After the set period for testing, random samples of embryos were removed for morphological analysis under stereoscopic microscopes. Results were analysed using analysis of variance (ANOVA) and Tukey's test at a 5% significance level and Trimmed Spearman-Karber Analysis to determine LC50-24 h. DMSO toxicity tests revealed that 5% and 10% concentrations showed the highest toxicity and differed from the control (P ? 0.05), 24h-LC50 was 437.4 ± 14.4 µL. MET was less toxic among the tested cryoprotectants and concentrations did not allow the determination of its LC50-24h. For tests with EG, concentrations of 3, 5 or 10% solutions resulted in a 100% mortality to tested embryos; EG was the tested cryoprotectant with the highest toxicity, with an LC50-24h average of 81.91 ± 35.3 µl. PMID:25255785

Ferreira, Arthur Vinícius Lourenço; Castro, Elias José Teles; Barbosa, Mariana Silva Alves; de Sousa, Míriam Luzia Nogueira Martins; de Araújo Neto, Manoel Paiva; Filho, Aldeney Andrade Soares; de Souza Sampaio, Celia Maria

2014-09-26

27

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

SciTech Connect

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.

Jackim, E.; Nacci, D.

1984-01-01

28

Toxicity and EROD-inducing potency of 24 polycyclic aromatic hydrocarbons (PAHs) in chick embryos  

Microsoft Academic Search

The toxicities (embryolethality) of 24 polycyclic aromatic hydrocarbons (PAHs) were determined in chick embryos using a 72-h test. The substances, dissolved in peanut oil, were injected into the air sacs of eggs preincubated for 7 days. LD50 values were determined for the four most toxic of the 24 compounds. Benzo [k] fluoranthene proved to be the most potent, with an

Björn Brunström; Dag Broman; Carina Näf

1991-01-01

29

Early developmental toxicity of saxitoxin on medaka (Oryzias melastigma) embryos.  

PubMed

Saxitoxin (STX) is the most potent paralytic shellfish poisoning toxin in crustaceans and molluscs, and is known to cause intoxication to humans and marine animals due to its neurotoxicity. However, the extent of its early developmental toxicity to marine species remains unknown. In this study, we examined the early developmental toxicity of STX using marine medaka (Oryzias melastigma) embryos as model. The medaka embryos were exposed to STX for four days, from the early blastula stage onwards, and this exposure period covered the main developmental stage of the central nervous system and somites. After exposure, the treated medaka eleutheroembryos at 15 day post fertilization exhibited abnormal growth with longer body length and relatively smaller yolk sac size. High cell proliferation, neuron development, and metabolism were confirmed using whole-mount immunostaining and two-dimensional electrophoresis. In summary, STX disturbed the normal growth of medaka embryos probably by affecting the metabolic rate in the exposed medaka embryos. PMID:24184516

Tian, Li; Cheng, Jinping; Chen, Xueping; Cheng, Shuk Han; Mak, Yim Ling; Lam, Paul Kwan Sing; Chan, Leo Lai; Wang, Mingfu

2014-01-01

30

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...

31

Toxicity of selenium to developing Xenopus laevis embryos  

Microsoft Academic Search

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

C. L. Browne; James N. Dumont

1979-01-01

32

Developmental toxicity assay using high content screening of zebrafish embryos.  

PubMed

Typically, time-consuming standard toxicological assays using the zebrafish (Danio rerio) embryo model evaluate mortality and teratogenicity after exposure during the first 2?days post-fertilization. Here we describe an automated image-based high content screening (HCS) assay to identify the teratogenic/embryotoxic potential of compounds in zebrafish embryos in vivo. Automated image acquisition was performed using a high content microscope system. Further automated analysis of embryo length, as a statistically quantifiable endpoint of toxicity, was performed on images post-acquisition. The biological effects of ethanol, nicotine, ketamine, caffeine, dimethyl sulfoxide and temperature on zebrafish embryos were assessed. This automated developmental toxicity assay, based on a growth-retardation endpoint should be suitable for evaluating the effects of potential teratogens and developmental toxicants in a high throughput manner. This approach can significantly expedite the screening of potential teratogens and developmental toxicants, thereby improving the current risk assessment process by decreasing analysis time and required resources. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:24871937

Lantz-McPeak, Susan; Guo, Xiaoqing; Cuevas, Elvis; Dumas, Melanie; Newport, Glenn D; Ali, Syed F; Paule, Merle G; Kanungo, Jyotshna

2015-03-01

33

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

PubMed Central

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

Fridman, Osvaldo; Corró, Lucrecia; Herkovits, Jorge

2004-01-01

34

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...

35

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...

36

Use of Medaka in Toxicity Testing  

PubMed Central

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

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

37

Toxicity of pendimethalin containing formulation and copper sulphate to chicken embryos.  

PubMed

The aim of this study was to determine the individual and combined toxic effects of STOMP 330 EC herbicide (33% pendimethalin) and copper sulphate on the development of chicken embryos. On the first day of incubation chicken eggs were dipped in the solution or emulsion of the test materials for 30 minutes. Applied concentration of copper sulphate was 0.01% and of herbicide STOMP 330 EC was 1.25%. The chicken embryos were examined for the followings: rate of embryo mortality, body weight, type of developmental anomalies, macroscopic examination. Our teratogenicity study revealed that, the individual toxic effect of copper sulphate and pendimethalin containing herbicide formulation (STOMP 330 EC) were embryotoxic but not teratogenic in chicken. The combined administration of STOMP 330 EC and copper sulphate did not increase the embryotoxic effect. PMID:25145238

Budai, P; Lehel, J; Marczali, Zs; Szabó, R

2013-01-01

38

DEVELOPMENTAL TOXICITY TESTING  

EPA Science Inventory

Contemporary developmental toxicity testing focuses on the evaluation of a variety of adverse developmental effects which include structural malformations, intrauterine death, growth retardation, and deficits in postnatal function. n the extrapolation of information from animal s...

39

Cytogenetic and developmental toxicity of cerium and lanthanum to sea urchin embryos  

E-print Network

Cytogenetic and developmental toxicity of cerium and lanthanum to sea urchin embryos Rahime Oral1 was to evaluate the toxicity of two rare earth elements (REE), cerium and lanthanum on sea urchin embryos and sperm. Sea urchin (Paracentrotus lividus) embryos were reared for 72 h in Ce(IV)- or La

Paris-Sud XI, Université de

40

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

SciTech Connect

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.

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

1993-01-01

41

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

PubMed

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

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

2014-01-01

42

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

PubMed

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. PMID:19545030

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

2009-04-15

43

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...

44

Japanese medaka (Oryzias latipes) embryo assay for developmental toxicity incorporating individual embryo incubations: Evaluations of controls, a pure compound (BaP), soil extracts, and stream effluents  

SciTech Connect

A non-indigenous, but useful fish species has been largely overlooked by organizations preparing protocols for toxicity testing in research and environmental regulation. The Japanese medaka (Oryzias latipes) has been used in basic and applied research in the United States and Japan for many years. All life-history stages have been used and studied, including numerous different types of embryo and embryo-larval assays. However, a medaka embryo assay has yet to be recommended by the American Society for Testing and Materials, the United States Environmental Protection Agency or the American Public Health Association for use as a test species in water quality control. The authors have developed and refined methods for evaluating toxicity and abnormalities in embryos exposed to contaminants in a variety of media. Individual embryos exposed to benzo[a]pyrene showed both increased mortalities and abnormalities. In the two field applications, individual embryos were exposed to: (1) soil extracts from two hydrocarbon-contaminated sites on U.S. Army Kwajalein Atoll, in the General Republic of the Marshall Islands, or (2) water samples from ten sites on East Fork Poplar Creek, in Oak Ridge, TN, a stream that originates inside the DOE Y-12 Plant. The two soil extracts were from diesel fuel-contaminated soil; treated embryos showed significant responses ranging from increased mortalities to abnormalities and developmental delays. The stream has a history of industrial contamination, including polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and heavy metals, (particularly mercury); other typical industrial discharges (i.e. chlorine, ammonia, and nitrates) are also present at some sites. Treatment groups showed high mortality and dose-dependent mortality in diluted samples compared to control and reference water samples. This study demonstrates the flexibility of this medaka embryo assay for assessing the toxicity of complex environmental sites.

Hull, C.G.

1993-01-01

45

The role of apoptosis in MCLR-induced developmental toxicity in zebrafish embryos.  

PubMed

We previously demonstrated that cyanobacteria-derived microcystin-leucine-arginine (MCLR) is able to induce developing toxicity, such as malformation, growth delay and also decreased heart rates in zebrafish embryos. However, the molecular mechanisms by which MCLR induces its toxicity during the development of zebrafish remain largely unknown. Here, we evaluate the role of apoptosis in MCLR-induced developmental toxicity. Zebrafish embryos were exposed to various concentrations of MCLR (0, 0.2, 0.5, 2, and 5.0 mg L(-1)) for 96 h, at which time reactive oxygen species (ROS) was significantly induced in the 2 and 5.0 mg L(-1) MCLR exposure groups. Acridine orange (AO) staining and terminal deoxynucleotide transferase-mediated deoxy-UTP nick end labelling (TUNEL) assay showed that MCLR exposure resulted in cell apoptosis. To test the apoptotic pathway, the expression pattern of several apoptotic-related genes was examined for the level of enzyme activity, gene and protein expression, respectively. The overall results demonstrate that MCLR induced ROS which consequently triggered apoptosis in the heart of developing zebrafish embryos. Our results also indicate that the p53-Bax-Bcl-2 pathway and the caspase-dependent apoptotic pathway play major roles in MCLR-induced apoptosis in the developing embryos. PMID:24555956

Zeng, Cheng; Sun, Hong; Xie, Ping; Wang, Jianghua; Zhang, Guirong; Chen, Nan; Yan, Wei; Li, Guangyu

2014-04-01

46

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

PubMed

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. PMID:24375845

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

2014-04-01

47

Acute toxicity of agricultural pesticides to embryo-larval and juvenile African catfish Clarias gariepinus.  

PubMed

Acute toxicities of Tihan 175 O-TEQ, as well as its active ingredients flubendiamide and spirotetramat, and of Thionex 350 EC (active compound endosulfan) were measured for embryo-larval and juvenile stages of the African catfish Clarias gariepinus to assess risks of pesticide use in the cotton basin in Benin (West Africa). For embryo-larval stages, Tihan was more toxic (LC5048h 20 ppm) than Thionex (LC5048h 56 ppm), and flubendiamide was more toxic (LC5048h 2.0 ppm) than spirotetramat (LC5048h 8.44 ppm). All decreased hatching rates. Tihan and spirotetramat disturbed larval swimming coordination; flubendiamide induced tail cleavage. For juvenile fish, Thionex was more toxic (LC5096h 0.22 ppm) than Tihan (LC5096h 8.8 ppm), and flubendiamide (LC5096h 4.7 ppm) was more toxic than spirotetramat (LC5096h 6.0 ppm). Eggs were more resistant than juvenile fish to all tested pesticides except flubendiamide. Although Thionex was more toxic to juvenile fish, replacing Thionex with Tihan may be undesirable for survival of eggs and larvae. PMID:23334459

Agbohessi, P T; Imorou Toko, I; Houndji, A; Gillardin, V; Mandiki, S N M; Kestemont, P

2013-05-01

48

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

PubMed

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. PMID:22488782

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

2012-06-01

49

The fish embryo test (FET): origin, applications, and future.  

PubMed

Originally designed as an alternative for the acute fish toxicity test according to, e.g., OECD TG 203, the fish embryo test (FET) with the zebrafish (Danio rerio) has been optimized, standardized, and validated during an OECD validation study and adopted as OECD TG 236 as a test to assess toxicity of embryonic forms of fish. Given its excellent correlation with the acute fish toxicity test and the fact that non-feeding developmental stages of fish are not categorized as protected stages according to the new European Directive 2010/63/EU on the protection of animals used for scientific purposes, the FET is ready for use not only for range-finding but also as a true alternative for the acute fish toxicity test, as required for a multitude of national and international regulations. If-for ethical reasons-not accepted as a full alternative, the FET represents at least a refinement in the sense of the 3Rs principle. Objections to the use of the FET have mainly been based on the putative lack of biotransformation capacity and the assumption that highly lipophilic and/or high molecular weight substances might not have access to the embryo due to the protective role of the chorion. With respect to bioactivation, the only substance identified so far as not being activated in the zebrafish embryo is allyl alcohol; all other biotransformation processes that have been studied in more detail so far were found to be present, albeit, in some cases, at lower levels than in adult fish. With respect to larger molecules, the extension of the test duration to 96 h (i.e., beyond hatch) has-at least for the substances tested so far-compensated for the reduced access to the embryo; however, more research is necessary to fully explore the applicability of the FET to substances with a molecular weight >3 kDa as well as substances with a neurotoxic mode of action. An extension of the endpoints to also cover sublethal endpoints makes the FET a powerful tool for the detection of teratogenicity, dioxin-like activity, genotoxicity and mutagenicity, neurotoxicity, as well as various forms of endocrine disruption. PMID:25395325

Braunbeck, Thomas; Kais, Britta; Lammer, Eva; Otte, Jens; Schneider, Katharina; Stengel, Daniel; Strecker, Ruben

2014-11-15

50

Embryo Toxic Effects of Depleted Uranium on the Morphology of the Mouse Fetus  

PubMed Central

Although the biokinetics, metabolism, and chemical toxicity of uranium are well known, until recently little attention was paid to the potential toxic effects of uranium on reproduction and development in mammals. In recent years, it has been shown that uranium is a developmental toxicant when given orally or subcutaneously (SC) to mice. Decreased fertility, embryo/fetal toxicity including teratogenicity, and reduced growth of the offspring have been observed following uranium exposure at different gestation periods. For investigating the effects of DU on pregnant animals, three groups (control, sham and test) of NMRI mice were chosen. In test group 4 mg/Kg of DU were administered intraperitonealy at 11 day of gestation, in sham group only normal saline injected to interior peritoneum as indicated in the test group and in Control group which was considered as the comparison base line of our research, no injection was made. Caesarean sections were performed at 15 day of the gestation; and their placentas were examined externally. Base on our results DU caused significant external anomalies, and caused a significant decrease (p < 0.05) in the weight and diameter of placentas, the number of the embryos, their body weight and crown-rump length of fetuses. PMID:24734072

Mirderikvand, Nina; Mohammadzadeh Asl, Baharak; Naserzadeh, Parvaneh; Shaki, Fatemeh; Shokrzadeh, Mohammad; Pourahmad, Jalal

2014-01-01

51

Embryo toxic effects of depleted uranium on the morphology of the mouse fetus.  

PubMed

Although the biokinetics, metabolism, and chemical toxicity of uranium are well known, until recently little attention was paid to the potential toxic effects of uranium on reproduction and development in mammals. In recent years, it has been shown that uranium is a developmental toxicant when given orally or subcutaneously (SC) to mice. Decreased fertility, embryo/fetal toxicity including teratogenicity, and reduced growth of the offspring have been observed following uranium exposure at different gestation periods. For investigating the effects of DU on pregnant animals, three groups (control, sham and test) of NMRI mice were chosen. In test group 4 mg/Kg of DU were administered intraperitonealy at 11 day of gestation, in sham group only normal saline injected to interior peritoneum as indicated in the test group and in Control group which was considered as the comparison base line of our research, no injection was made. Caesarean sections were performed at 15 day of the gestation; and their placentas were examined externally. Base on our results DU caused significant external anomalies, and caused a significant decrease (p < 0.05) in the weight and diameter of placentas, the number of the embryos, their body weight and crown-rump length of fetuses. PMID:24734072

Mirderikvand, Nina; Mohammadzadeh Asl, Baharak; Naserzadeh, Parvaneh; Shaki, Fatemeh; Shokrzadeh, Mohammad; Pourahmad, Jalal

2014-01-01

52

Differential developmental toxicity of naphthoic acid isomers in medaka (Oryzias latipes) embryos  

PubMed Central

Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent pollutants that readily undergo biotic and abiotic conversion to numerous transformation products in rivers, lakes and estuarine sediments. Here we characterize the developmental toxicity of four PAH transformation products each structural isomers of hydroxynaphthoic acid: 1H2NA, 2H1NA, 2H3NA, and 6H2NA. Medaka fish (Oryzias latipes) embryos and eleutheroembryos were used to determine toxicity. A 96-well micro-plate format was used to establish a robust, statistically significant platform for assessment of early life stages. Individual naphthoic acid isomers demonstrated a rank order of toxicity with 1H2NA > 2H1NA > 2H3NA > 6H2NA being more toxic. Abnormalities of circulatory system were most pronounced including pericardial edema and tube heart. To determine if HNA isomers were AhR ligands, spatial-temporal expression and activity of CYP1A was measured via in vivo EROD assessments. qPCR measurement of CYP1A induction proved different between isomers dosed at respective concentrations affecting 50% of exposed individuals (EC50s). In vitro, all ANH isomers transactivated mouse AhR using a medaka CYP1A promoter specific reporter assay. Circulatory abnormalities followed P450 induction and response was consistent with PAH toxicity. A 96-well micro-plates proved suitable as exposure chambers and provided statistically sound evaluations as well as efficient toxicity screens. Our results demonstrate the use of medaka embryos for toxicity analysis thereby achieving REACH objectives for the reduction of adult animal testing in toxicity evaluations. PMID:18433798

Carney, Michael W.; Erwin, Kyle; Hardman, Ron; Yuen, Bonny; Volz, David C.; Hinton, David E.; Kullman, Seth W.

2013-01-01

53

The Future of Toxicity Testing  

Microsoft Academic Search

In 2007, the U.S. National Research Council (NRC) released a report, “Toxicity Testing in the 21st Century: A Vision and a Strategy,” that proposes a paradigm shift for toxicity testing of environmental agents. The vision is based on the notion that exposure to environmental agents leads to adverse health outcomes through the perturbation of toxicity pathways that are operative in

Melvin E. Andersen; Mustafa Al-Zoughool; Maxine Croteau; Margit Westphal; Daniel Krewski

2010-01-01

54

The toxicity of heavy metals to embryos of the American oyster Crassostrea virginica  

Microsoft Academic Search

The acute toxicity of 11 heavy metals to embryos of the American oyster Crassostrea virginica was studied and the concentrations at which 50% of the embryos did not develop were determined. The most toxic metals and their LC50 values were mercury (0.0056 ppm), silver (0.0058 ppm), copper (0.103 ppm) and zinc (0.31 ppm). Those metals that were not as toxic

A. Calabrese; R. S. Collier; D. A. Nelson; J. R. MacInnes

1973-01-01

55

Drosophila Embryos as Model to Assess Cellular and Developmental Toxicity of Multi-Walled Carbon Nanotubes (MWCNT) in Living Organisms  

PubMed Central

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. PMID:24558411

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

2014-01-01

56

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...

57

Effects of photoinduced toxicity of fluoranthene on amphibian embryos and larvae  

SciTech Connect

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.

Hatch, A.C. [Oregon State Univ., Corvallis, OR (United States). Dept. of Zoology; Burton, G.A. Jr. [Wright State Univ., Dayton, OH (United States). Dept. of Biological Sciences

1998-09-01

58

FURTHER DEVELOPMENT OF RODENT WHOLE EMBRYO CULTURE: SOLVENT TOXICITY AND WATER INSOLUBLE COMPOUND DELIVERY SYSTEM  

EPA Science Inventory

In order to study the in vitro embryotoxicity and dysmorphogenesis of water insoluble compounds, solvents or chemical delivery systems of low toxicity and teratogenicity to the developing embryo must be found. Therefore, day 10.5 rat embryos were cultured for 2 days in whole rat ...

59

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...

60

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. ...

61

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

PubMed Central

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

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

2013-01-01

62

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

PubMed

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

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

2013-01-01

63

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

SciTech Connect

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.

Schweitzer, L.; Suffet, I. [Univ. of California, Los Angeles, CA (United States); Hose, J. [Occidental Coll., Los Angeles, CA (United States); Bay, S. [Southern California Coastal Water Research Project, Westminster, CA (United States)

1995-12-31

64

Assessing the toxicity to fish embryos of surface water from the Watts Bar Lake/Clinch River system  

SciTech Connect

Successful reproduction of fish populations requires the successful development of offspring into new reproductive cohorts. In order to evaluate the ability of fish offspring to survive and develop properly in the Watts Bar Lake/Clinch River system downstream of the Department of Energy facilities in Oak Ridge, TN, a series of fish embryo-larval toxicity tests were conducted on surface water samples from Poplar Creek and the Clinch River adjacent to the Oak Ridge Reservation. Quarterly tests were conducted over an eighteen-month interval with embryos from laboratory stocks of the Japanese medaka (Oryzias latipes). Eggs obtained from largemouth bass (Micropterus salmoides) and redbreast sunfish (Lepomis auritus) collected from reference sites during their respective breeding seasons were fertilized in vitro for additional embryo-larval tests utilizing fish species indigenous to the Watts Bar/Clinch River system. Average survival of medaka embryos decreased significantly in water from Poplar Creek sites within the Oak Ridge Reservation, coincident with an increase in the prevalence of certain developmental abnormalities. Similar but less pronounced results were also obtained with redbreast sunfish embryos. Development of largemouth bass eggs was not adversely affected by any of the tested water samples. These findings suggest that the development of fish eggs and fry in certain reaches of the Watts Bar Lake/Clinch River system may be negatively impacted by activities on the Oak Ridge Reservation.

Ivey, L.J.; Niemela, S.L.; McCracken, M.K.; Greeley, M.S. Jr. [Oak Ridge National Lab., TN (United States)

1995-12-31

65

RAPID AQUATIC TOXICITY ASSAY UTILIZING LABELED THYMIDINE INCORPORATION IN SEA URCHIN EMBRYOS  

EPA Science Inventory

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...

66

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

PubMed

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. PMID:23601886

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

2013-05-15

67

Proteomic Signatures of the Zebrafish (Danio rerio) Embryo: Sensitivity and Specificity in Toxicity Assessment of Chemicals  

PubMed Central

Studies using embryos of the zebrafish Danio rerio (DarT) instead of adult fish for characterising the (eco-) toxic potential of chemicals have been proposed as animal replacing methods. Effect analysis at the molecular level might enhance sensitivity, specificity, and predictive value of the embryonal studies. The present paper aimed to test the potential of toxicoproteomics with zebrafish eleutheroembryos for sensitive and specific toxicity assessment. 2-DE-based toxicoproteomics was performed applying low-dose (EC10) exposure for 48?h with three-model substances Rotenone, 4,6-dinitro-o-cresol (DNOC) and Diclofenac. By multivariate “pattern-only” PCA and univariate statistical analyses, alterations in the embryonal proteome were detectable in nonetheless visibly intact organisms and treatment with the three substances was distinguishable at the molecular level. Toxicoproteomics enabled the enhancement of sensitivity and specificity of the embryonal toxicity assay and bear the potency to identify protein markers serving as general stress markers and early diagnosis of toxic stress. PMID:22084678

Hanisch, Karen; Küster, Eberhard; Altenburger, Rolf; Gündel, Ulrike

2010-01-01

68

Influence of sediment composition on PAH toxicity using zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes) embryo-larval assays.  

PubMed

Due to hydrophobic and persistent properties, polycyclic aromatic hydrocarbons (PAHs) have a high capacity to accumulate in sediment. Sediment quality criteria, for the assessment of habitat quality and risk for aquatic life, include understanding the fate and effects of PAHs. In the context of European regulation (REACH and Water Framework Directive), the first objective was to assess the influence of sediment composition on the toxicity of two model PAHs, benzo[a]pyrene and fluoranthene using 10-day zebrafish embryo-larval assay. This procedure was undertaken with an artificial sediment in order to limit natural sediment variability. A suitable sediment composition might be then validated for zebrafish and proposed in a new OECD guideline for chemicals testing. Second, a comparative study of toxicity responses from this exposure protocol was then performed using another OECD species, the Japanese medaka. The potential toxicity of both PAHs was assessed through lethal (e.g., survival, hatching success) and sublethal endpoints (e.g., abnormalities, PMR, and EROD) measured at different developmental stages, adapted to the embryonic development time of both species. Regarding effects observed for both species, a suitable artificial sediment composition for PAH toxicity testing was set at 92.5 % dry weight (dw) silica of 0.2-0.5-mm grain size, 5 % dw kaolin clay without organic matter for zebrafish, and 2.5 % dw blond peat in more only for Japanese medaka. PAH bioavailability and toxicity were highly dependent on the fraction of organic matter in sediment and of the K ow coefficients of the tested compounds. The biological responses observed were also dependent of the species under consideration. Japanese medaka embryos appeared more robust than zebrafish embryos for understanding the toxicity of PAHs following a sediment contact test, due to the longer exposure duration and lower sensitivity of sediment physical properties. PMID:25175355

Perrichon, Prescilla; Le Bihanic, Florane; Bustamante, Paco; Le Menach, Karyn; Budzinski, Hélčne; Cachot, Jérôme; Cousin, Xavier

2014-12-01

69

The stability, toxicity and effectiveness of unmodified and phosphorothioate antisense oligodeoxynucleotides in Xenopus oocytes and embryos.  

PubMed Central

The properties of antisense phosphorothioate and unmodified oligodeoxynucleotides have been studied in Xenopus oocytes and embryos. We find that phosphorothioates, like unmodified oligodeoxynucleotides, can degrade Vg1 mRNA in oocytes via an endogenous RNase H-like activity. In oocytes, phosphorothioate oligodeoxynucleotides are more stable than unmodified oligodeoxynucleotides and are more effective in degrading Vg1 mRNA. In embryos, neither unmodified nor phosphorothioate deoxyoligonucleotides were effective in degrading Vg1 message at sub-toxic doses. Images PMID:1692405

Woolf, T M; Jennings, C G; Rebagliati, M; Melton, D A

1990-01-01

70

Toxicity of Heparin in Postimplantation Whole-Embryo Culture  

Microsoft Academic Search

Cranial neural tube defects occur when heparin is added to the culture media of postimplantation rat embryos undergoing organogenesis in vitro. Timed-exposure studies were undertaken to determine whether the defects caused by heparin were the result of defective folding and fusion of the neural folds, or due to reopening of a closed neural tube. Experiments were also undertaken to elucidate

Gregory J. Kesby

2000-01-01

71

METAL TOXICITY TO EMBRYOS AND LARVAE OF EIGHT SPECIES OF FRESHWATER FISH--II: COPPER  

EPA Science Inventory

Fish larvae and early juveniles of all species tested (brook trout, rainbow trout, brown trout, lake trout, northern pike, white sucker, herring and smallmouth bass) were more sensitive to copper than the embryos. Embryo survival was affected only at the higher concentrations tes...

72

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

NASA Astrophysics Data System (ADS)

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 ?g/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 ?g/ml or above. Only larvae exposed to >= 5 ?g/ml SWCNTs showed significantly reduced survival rates. About 50% of the embryos exposed to 5 ?g/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 ?g/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 ?g/ml.

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

2011-07-01

73

NEW EARLY LIFE-STAGE TOXICITY TEST USING THE CALIFORNIA GRUNION (LEURESTHES TENUIS) AND RESULTS WITH CHLORPYRIFOS  

EPA Science Inventory

California grunion were continuously exposed as embryos and fry to technical chlorpyrifos in two toxicity tests conducted in the same exposure apparatus. The first test, a 35-day early life-stage (ELS) test, began with approximately 2.5-day-old embryos that were exposed in flow-t...

74

Influence of storage methods, refrigeration or freezing, on the toxicity of wastewater samples to oyster embryos.  

PubMed

One of the main concerns in wastewater whole effluent assessment is the sampling phase and the sample chain of custody before any toxicity evaluation. The major problem is related to establishing the correct method for sample storage in order to perform toxicity bioassays. The toxicity of some domestic and glass factory industrial wastewater samples stored both by refrigeration at 4 +/- 1 degrees C for no more than three days, and freezing at -18 +/- 1 degrees C for no more than one month was compared via the embryo larval development bioassay with the oyster Crassostrea gigas. The results showed no significant differences between the toxicities of refrigerated and frozen wastewater samples. The wastewater classification, according to a score based on four toxicity classes, showed that the preservation methods did not alter the toxicity classification of the samples. In particular, it was demonstrated that the samples considered as 'not acutely toxic' after refrigeration were also found to have this classification after freezing. PMID:19603701

Libralato, G; Avezzů, F; Losso, C; Volpi Ghirardini, A

2009-05-01

75

The toxicity of silver nanoparticles to zebrafish embryos increases through sewage treatment processes.  

PubMed

Silver nanoparticles (AgNPs) are widely believed to be retained in the sewage sludge during sewage treatment. The AgNPs and their derivatives, however, re-enter the environment with the sludge and via the effluent. AgNP were shown to occur in surface water, while evidence of a potential toxicity of AgNPs in aquatic organisms is growing. This study aims to examine the toxicity of AgNPs to the embryos of the aquatic vertebrate model zebrafish (Danio rerio) before and after sewage treatment plants (STPs) processes. Embryos were treated with AgNP (particle size: >90 % <20 nm) and AgNO3 in ISO water for 48 h and consequently displayed effects such as delayed development, tail malformations and edema. For AgNP, the embryos were smaller than the controls with conspicuously smaller yolk sacs. The corresponding EC50 values of 48 hours post fertilization (hpf) were determined as 73 ?g/l for AgNO3 and 1.1 mg/l for AgNP. Whole-mount immunostainings of primary and secondary motor neurons also revealed secondary neurotoxic effects. A TEM analysis confirmed uptake of the AgNPs, and the distribution within the embryo suggested absorption across the skin. Embryos were also exposed (for 48 h) to effluents of AgNP-spiked model STP with AgNP influent concentrations of 4 and 16 mg/l. These embryos exhibited the same malformations than for AgNO3 and AgNPs, but the embryo toxicity of the sewage treatment effluent was higher (EC50 = 142 ?g/l; 48 hpf). On the other hand, control STP effluent spiked with AgNPs afterwards was less toxic (EC50 = 2.9 mg/l; 48 hpf) than AgNPs in ISO water. This observation of an increased fish embryo toxicity of STP effluents with increasing AgNP influent concentrations identifies the accumulation of AgNP in the STP as a potential source of effluent toxicity. PMID:23975539

Muth-Köhne, Elke; Sonnack, Laura; Schlich, Karsten; Hischen, Florian; Baumgartner, Werner; Hund-Rinke, Kerstin; Schäfers, Christoph; Fenske, Martina

2013-10-01

76

Toxicity evaluation of biodegradable chitosan nanoparticles using a zebrafish embryo model  

PubMed Central

Background Although there are a number of reports regarding the toxicity evaluation of inorganic nanoparticles, knowledge on biodegradable nanomaterials, which have always been considered safe, is still limited. For example, the toxicity of chitosan nanoparticles, one of the most widely used drug/gene delivery vehicles, is largely unknown. In the present study, the zebrafish model was used for a safety evaluation of this nanocarrier. Methods Chitosan nanoparticles with two particle sizes were prepared by ionic cross-linking of chitosan with sodium tripolyphosphate. Chitosan nanoparticles of different concentrations were incubated with zebrafish embryos, and ZnO nanoparticles were used as the positive control. Results Embryo exposure to chitosan nanoparticles and ZnO nanoparticles resulted in a decreased hatching rate and increased mortality, which was concentration-dependent. Chitosan nanoparticles at a size of 200 nm caused malformations, including a bent spine, pericardial edema, and an opaque yolk in zebrafish embryos. Furthermore, embryos exposed to chitosan nanoparticles showed an increased rate of cell death, high expression of reactive oxygen species, as well as overexpression of heat shock protein 70, indicating that chitosan nanoparticles can cause physiological stress in zebrafish. The results also suggest that the toxicity of biodegradable nanocarriers such as chitosan nanoparticles must be addressed, especially considering the in vivo distribution of these nanoscaled particles. Conclusion Our results add new insights into the potential toxicity of nanoparticles produced by biodegradable materials, and may help us to understand better the nanotoxicity of drug delivery carriers. PMID:22267920

Hu, Yu-Lan; Qi, Wang; Han, Feng; Shao, Jian-Zhong; Gao, Jian-Qing

2011-01-01

77

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

Microsoft Academic Search

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 B1, carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in

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

2011-01-01

78

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

SciTech Connect

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.

Schweitzer, L.E.; Suffet, I.H. [Univ. of California, Los Angeles, CA (United States); Hose, J.E. [Occidental Coll., Los Angeles, CA (United States). Dept. of Biology; Bay, S.M. [Southern California Coastal Water Research Project, Westminster, CA (United States)

1997-07-01

79

Influence of the salinity adjustment methods, salts and brine, on the toxicity of wastewater samples to mussel embryos.  

PubMed

One of the main problems of the Whole Effluent Toxicity is related to the use of bioindicator species representative of the target environment. Most wastewater discharges are of fresh water, so their salinity has to be adjusted when they are discharged to transitional and marine coastal waters, in order to perform toxicity bioassays with reliable organisms. At the moment, there is no optimum technique to allow sample salinity to be adjusted and no specific information regarding salinity adjustment when bivalves are being considered for toxicity test performance. This paper provides information on the potential use of different methods to adjust the salinity of hotel/domestic wastewater samples with different brands of natural and synthetic Dry Salts (DS) and HyperSaline Brine (HSB) for use in the embryo larval development bioassay with the mussel Mytilus galloprovincialis. HyperSaline Brine derived from reconstructed artificial seawater proved to be more viable for wastewater salinity adjustment than DS. PMID:19213470

Libralato, G; Losso, C; Avezzů, F; Volpi Ghirardini, A

2009-01-01

80

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

PubMed

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. PMID:24992311

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

2015-02-01

81

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

PubMed

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. PMID:24375932

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

2014-04-01

82

Toxic effects of triazophos on rare minnow (Gobiocypris rarus) embryos and larvae.  

PubMed

Triazophos (TAP) has been widely used in agriculture for controlling insect pests and is a known organophosphorus pesticide. Due to TAP characteristics, such as high chemical and photochemical stability, its potential toxicity to aquatic organisms has gained great interest. To explore the potential developmental toxicity of TAP, Gobiocypris rarus embryos and larvae were exposed to various concentrations of TAP (0.1-15 mg L(-1)) until 72 h. Results showed that values of 72 h LC50 and EC50 were 7.44 and 5.60 mg L(-1) for embryos, 2.52 and 1.37 mg L(-1) for larvae. Increased malformation, decreased heart rate and body length provide a gradual concentration-dependent pattern. Enzyme activities and mRNA levels were significantly changed even at low concentration (0.05 mg L(-1) for embryos and 0.01 mg L(-(1) for larvae). Overall, the present study points out that TAP is likely a risk to the early development of G. rarus. The information presented in this study will be helpful in better understanding the toxicity induced by TAP in fish embryos and larvae. PMID:24875911

Zhu, Bin; Gong, Yu-Xin; Liu, Lei; Li, Dong-Liang; Wang, Yuan; Ling, Fei; Wang, Gao-Xue

2014-08-01

83

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

PubMed

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 LC?? and EC?? values were used to calculate the teratogenicity index (TI) for the different substances, and the EC?? 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. PMID:21237239

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

2011-03-15

84

670 nanometer light treatment attenuates dioxin toxicity in the developing chick embryo.  

PubMed

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an acutely toxic anthropogenic chemical. Treatment with a red to near-infrared (630-1000 nm) light-emitting diode (LED) attenuates the toxicant-induced oxidative stress and energy deficit in neuronal cell culture. For this study, fertile chicken (Gallus gallus) eggs were injected once at the start of incubation with sunflower oil vehicle or 200 pg TCDD/g egg (200 parts per trillion), an environmentally relevant dose. Daily LED treatment after TCDD exposure reduced embryonic mortality by 47%. LED treatment of TCDD-exposed eggs also decreased the hepatic oxidized-to-reduced glutathione ratio by 88%. Activities of other hepatic indicators of oxidative stress, such as glutathione reductase and catalase, were increased after LED treatment of TCDD-exposed eggs. Our study demonstrates that 670 nm phototherapy can mitigate the oxidative stress and energy deficit resulting from developmental exposure to TCDD while reducing TCDD-induced embryo mortality. Moreover, LED treatment restores hepatic enzyme activities to control levels in TCDD-exposed embryos. The effective attenuation of TCDD-induced embryo toxicity by LED treatment could extend to mitigating the effects of other teratogens that induce oxidative and energy stress. PMID:17163486

Yeager, Ronnie L; Lim, Jinhwan; Millsap, Deborah S; Jasevicius, Ashley V; Sanders, Ruth A; Whelan, Harry T; Watkins, John B; Eells, Janis T; Henshel, Diane S

2006-01-01

85

Toxicity to embryo and adult zebrafish of copper complexes with two malonic acids as models for dissolved organic matter  

SciTech Connect

The toxicity to embryo and adult zebrafish (Danio rerio) of Cu complexes with two substituted malonic acids, benzyl- and n-hexadecyl-, chosen as models for low-molecular-weight natural dissolved organic matter, were investigated. Toxicity test solutions at pH 6.5 {+-} 0.1 with the required Cu ion-specific electrode. In the absence of malonic acids, concentrations of Cu{sup 2+} up to 1.13 {mu}mol/L increased the embryo hatching time from approx. 2 d in control solutions (no Cu or malonic acid) and solutions containing malonic acids without Cu to approx. 8 d. The Cu-benzylmalonic acid complex in the presence of inorganic Cu species did not delay hatching beyond that attributable to Cu{sup 2+}. In contrast, 0.60 {mu}mol/L Cu-n-hexadecylmalonic complexes delayed hatching by 5.5 d in excess of that attributable to 1.13 {mu}mol/L Cu{sup 2+}, assuming that the hatching delays caused by the different Cu species were additive, possibly because of Cu entry into the embryo as the lipophilic Cu-n-hexadecylmalonic complex. None of the Cu-malonic acid complexes was acutely toxic to adult zebrafish at concentrations up to 1.4 {mu}mol/L, possibly because Cu was removed from the Cu-malonic acid complexes by stronger chelating groups at the gill surface. Substituted malonic acids with similar proton and Cu association constants can be readily prepared with a variety of simple substituents, radiolabeled if required. Their results show that these acids could be useful ligands for investigating intracellular transport and metabolism of metal-organic complexes.

Palmer, F.B.; Evans, C.W. [Univ. of Auckland (New Zealand); Butler, C.A. [Woodward Clyde NZ Ltd., Auckland (New Zealand); Timperley, M.H. [National Inst. of Water and Atmospheric Research, Auckland (New Zealand)

1998-08-01

86

A new developmental toxicity test for pelagic fish using anchoveta (Engraulis ringens J.).  

PubMed

A series of six 96-h static bioassays were performed to validate the use of anchoveta (Engraulis ringens) embryos as test organisms for ecotoxicological studies. The standardization protocol utilized potassium dichromate (K(2)Cr(2)O(7)) as a reference toxicant and egg mortality as the endpoint. The results indicated that the mean sensitivity of anchoveta embryos to potassium dichromate was 156.1 mg L(-1) (range: 131-185 mg L(-1)). The statistical data analysis showed high homogeneity in LC50 values among bioassays (variation coefficient = 11.02%). These results demonstrated that the protocol and handling procedures implemented for the anchoveta embryo bioassays comply with international standards for intra-laboratory precision. After secondary treatment, an effluent from a modern Kraft pulp mill was tested for E. ringens embryo toxicity, finding no significant differences from the controls. PMID:19333532

Llanos-Rivera, A; Castro, L R; Silva, J; Bay-Schmith, E

2009-07-01

87

PRESENT APPROACHES TO TOXICITY TESTING - A PERSPECTIVE  

EPA Science Inventory

Interest in aquatic toxicity tests is increasing as more emphasis is placed on control of highly toxic pollutants. While this interest offers an opportunity to increase the use of aquatic toxicity tests, there is a responsibility to recognize their limitations. Aquatic toxicology...

88

Aryl hydrocarbon receptor 2 mediates the toxicity of Paclobutrazol on the digestive system of zebrafish embryos.  

PubMed

Paclobutrazol (PBZ), a trazole-containing fungicide and plant growth retardant, has been widely used for over 30 years to regulate plant growth and promote early fruit setting. Long-term usage of PBZ in agriculture and natural environments has resulted in residual PBZ in the soil and water. Chronic exposure to waterborne PBZ can cause various physiological effects in fish, including hepatic steatosis, antioxidant activity, and disruption of spermatogenesis. We have previously shown that PBZ also affects the rates of zebrafish embryonic survival and hatching, and causes developmental failure of the head skeleton and eyes; here, we further show that PBZ has embryonic toxic effects on digestive organs of zebrafish, and describe the underlying mechanisms. PBZ treatment of embryos resulted in dose-dependent morphological and functional abnormalities of the digestive organs. Real-time RT-PCR and in situ hybridization were used to show that PBZ strongly induces cyp1a1 expression in the digestive system, and slightly induces ahr2 expression in zebrafish embryos. Knockdown of ahr2 with morpholino oligonucleotides prevents PBZ toxicity. Thus, the toxic effect of PBZ on digestive organs is mediated by AhR2, as was previously reported for retene and TCDD. These findings have implications for understanding the potential toxicity of PBZ during embryogenesis, and thus the potential impact of fungicides on public health and the environment. PMID:25500619

Wang, Wen-Der; Chen, Guan-Ting; Hsu, Hwei-Jan; Wu, Chang-Yi

2015-02-01

89

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

PubMed

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. PMID:22052622

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

2014-02-01

90

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

PubMed

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. PMID:25303653

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

2015-01-01

91

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...

92

Assessment of trifloxystrobin uptake kinetics, developmental toxicity and mRNA expression in rare minnow embryos.  

PubMed

Trifloxystrobin (TFS) is the widely used strobilurin fungicide. However, little information is so far available regarding the uptake kinetics and developmental toxicity of TFS to fish. The present study was conducted to investigate the uptake kinetics, potential environment risk and toxicity of TFS on Gobiocypris rarus embryos. Results revealed that increased malformation, decreased body length and heart rate, affected spontaneous movement and swimming speed provide a gradual concentration-dependent manner; values of 144h LC50 (median lethal concentration) and EC50 (median effective concentration) were 1.11 and 0.86?gL(-1). Continuous exposure to TFS resulted in a steady accumulation with no evidence of elimination. Enzyme activities were significantly changed; reactive oxygen species and DNA damage were significantly induced after TFS treatment. Certain genes related to cell apoptosis (p53), metabolism (cyp1a), stress response (hsp70) and blood vessels (vezf1) development were all significantly up-regulated. This is the first study to define uptake kinetics and to focus on behavioral consequences, physiological changes and mRNA expression following TFS exposure in the early life stages of fish. Our results suggest that TFS is highly toxic to fish embryos. PMID:25240160

Zhu, Bin; Liu, Guang-Lu; Liu, Lei; Ling, Fei; Wang, Gao-Xue

2015-02-01

93

Triazole-induced toxicity in developing rare minnow (Gobiocypris rarus) embryos.  

PubMed

Using rare minnow (Gobiocypris rarus) at early-life stages as experimental models, the developmental toxicity of five widely used triazole fungicides (myclobutanil, fluconazole, flusilazole, triflumizole, and epoxiconazole) were investigated following exposure to 1-15 mg/L for 72 h. Meanwhile, morphological parameters (body length, body weight, and heart rate), enzyme activities (superoxide dismutase (SOD), glutathione S-transferase (GST), adenosine triphosphatase (ATPase), and acetyl cholinesterase (AChE)), and mRNA levels (hsp70, mstn, mt, apaf1, vezf1, and cyp1a) were also recorded following exposure to 0.2, 1.0, and 5.0 mg/L for 72 h. Results indicated that increased malformation and mortality, decreased body length, body weight, and heart rate provide a concentration-dependent pattern; values of 72 h LC50 (median lethal concentration) and EC50 (median effective concentration) ranged from 3 to 12 mg/L. Most importantly, the results of the present study suggest that even at the lowest concentration, 0.2 mg/L, five triazole fungicides also caused notable changes in enzyme activities and mRNA levels. Overall, the present study points out that those five triazole fungicides are highly toxic to the early development of G. rarus embryos. The information presented in this study will be helpful in better understanding the toxicity induced by triazole fungicides in fish embryos. PMID:25028328

Zhu, Bin; Liu, Lei; Gong, Yu-Xin; Ling, Fei; Wang, Gao-Xue

2014-12-01

94

Synthesis, culture medium stability, and in vitro and in vivo zebrafish embryo toxicity of metal-organic framework nanoparticles.  

PubMed

Metal-organic frameworks (MOFs) are among the most attractive porous materials available today. They have garnered much attention for their potential utility in many different areas such as gas storage, separation, catalysis, and biomedicine. However, very little is known about the possible health or environmental risks of these materials. Here, the results of toxicity studies on sixteen representative uncoated MOF nanoparticles (nanoMOFs), which were assessed for cytotoxicity to HepG2 and MCF7 cells in vitro, and for toxicity to zebrafish embryos in vivo, are reported. Interestingly, there is a strong correlation between their in vitro toxicity and their in vivo toxicity. NanoMOFs were ranked according to their respective in vivo toxicity (in terms of the amount and severity of phenotypic changes observed in the treated zebrafish embryos), which varied widely. Altogether these results show different levels of toxicity of these materials; however, leaching of solubilized metal ions plays a main role. PMID:25504892

Ruyra, Ŕngels; Yazdi, Amirali; Espín, Jordi; Carné-Sánchez, Arnau; Roher, Nerea; Lorenzo, Julia; Imaz, Inhar; Maspoch, Daniel

2015-02-01

95

Toxicity of cylindrospermopsin, and other apparent metabolites from Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum, to the zebrafish (Danio rerio) embryo  

PubMed Central

Cyanobacteria produce a diverse array of toxic or otherwise bioactive compounds that pose growing threats to human and environmental health. We utilized the zebrafish (Danio rerio) embryo, as a model of vertebrate development, to investigate the inhibition of development pathways (i.e. developmental toxicity) by the cyanobacterial toxin, cylindrospermopsin (CYN), as well as extracts from various isolates of Cylindrospermopsis raciborskii and Aphanizomenon ovalisporum. CYN was toxic only when injected directly into embryos, but not by direct immersion at doses up to 50 ?g/ml. Despite the dose dependency of toxicity observed following injection of CYN, no consistent patterns of developmental defects were observed, suggesting that toxic effects of CYN may not target specific developmental pathways. In contrast, direct immersion of embryos in all of the extracts resulted in both increased mortality and reproducible, consistent, developmental dysfunctions. Interestingly, there was no correlation of developmental toxicity observed for these extracts with the presence of CYN or with previously reported toxicity for these strains. These results suggest that CYN is lethal to zebrafish embryos, but apparently inhibits no specific developmental pathways, whereas other apparent metabolites from C. raciborskii and A. ovalisporum seem to reproducibly inhibit development in the zebrafish model. Continued investigation of these apparent, unknown metabolites is needed. PMID:19087885

Berry, John P.; Gibbs, Patrick D.L.; Schmale, Michael C.; Saker, Martin L.

2012-01-01

96

Comparison of Methods to Obtain a Liquid Phase in Marine Sediment Toxicity Bioassays with Paracentrotus lividus Sea Urchin Embryos  

Microsoft Academic Search

Sediment toxicity bioassays using planktonic organisms are widespread tools in environmental quality assessment, but they\\u000a have limitations because the method for extracting and diluting the liquid phase may affect the final toxicity. The present\\u000a study compares the toxicity on sea urchin embryos and larvae of elutriates and pore water obtained from intertidal sediments\\u000a by various methods. The effects of mixing

R. Beiras

2002-01-01

97

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

PubMed Central

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

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

2004-01-01

98

GUIDELINES FOR CONDUCTING EARLY LIFE STAGE TOXICITY TESTS WITH JAPANESE MEDAKA (ORYZIAS LATIPES)  

EPA Science Inventory

This manual represents a procedural guide for conducting embryo-larval early life stage (ELS) toxicity tests with Japanese medaka (Oryzias latipes). hese procedures are based upon evaluation of published papers and recent methods development work conducted at our laboratory in Du...

99

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

SciTech Connect

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.

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

2007-07-15

100

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

PubMed

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 ?g/l showed a similar toxicological behaviour with a trend corresponding to the pesticide concentrations. At high concentration (500 ?g/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. PMID:22101977

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

2012-04-01

101

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

PubMed Central

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

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

2012-01-01

102

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...

103

RAPID AQUATIC TOXICITY ASSAY USING INCORPORATION OF TRITIATED-THYMIDINE INTO SEA URCHIN, 'ARBACIA PUNCTULATA', EMBRYO: EVALUATION OF TOXICANT EXPOSURE PROCEDURES  

EPA Science Inventory

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 toxican...

104

Comparison of Diazinon Toxicity to Embryos of Xenopus laevis and Danio rerio ; Degradation of Diazinon in Water  

Microsoft Academic Search

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,\\u000a respectively. The 96-h LC50 diazinon values demonstrated

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

2011-01-01

105

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

PubMed

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. PMID:24375551

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

2014-04-01

106

Developmental toxicity and stress protein responses in zebrafish embryos after exposure to diclofenac and its solvent, DMSO  

Microsoft Academic Search

One of the most frequently detected pharmaceuticals in environmental water samples is the anti-rheumatic drug, diclofenac. Despite its increasing environmental significance, investigations concerning the effects of this drug on the early developmental stages of aquatic species are lacking up to now. To determine the developmental toxicity and proteotoxicity of this drug on the growing fish embryos, eggs of zebrafish were

A. V. Hallare; H.-R. Köhler; R. Triebskorn

2004-01-01

107

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

SciTech Connect

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.

Nemeth, Kimberly A. [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107 (United States); Singh, Amar V. [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107 (United States); School of Dentistry, Birth Defects Center, University of Louisville, 501 South Preston Street, Louisville, KY 40202 (United States); Knudsen, Thomas B. [Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107 (United States) and School of Dentistry, Birth Defects Center, University of Louisville, 501 South Preston Street, Louisville, KY 40202 (United States)]. E-mail: thomas.knudsen@louisville.edu

2005-08-07

108

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

PubMed

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. PMID:25259848

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

109

Toxicity assessment of TiO? nanoparticles in zebrafish embryos under different exposure conditions.  

PubMed

The popularity of TiO2 nanoparticles (nano-TiO2) lies in their wide range of nanotechnological applications, together with low toxicity. Meanwhile, recent studies have shown that the photocatalytic properties of this material can result in alterations in their behavior in the environment, causing effects that have not yet been fully elucidated. The objective of this study was to evaluate the toxicity of two formulations of nano-TiO2 under different illumination conditions, using an experimental model coherent with the principle of the three Rs of alternative animal experimentation (reduction, refinement, and replacement). Embryos of the fish Danio rerio were exposed for 96h to different concentrations of nano-TiO2 in the form of anatase (TA) or an anatase/rutile mixture (TM), under either visible light or a combination of visible and ultraviolet light (UV). The acute toxicity and sublethal parameters evaluated included survival rates, malformation, hatching, equilibrium, and overall length of the larvae, together with biochemical biomarkers (specific activities of catalase (CAT), glutathione S-transferase (GST), and acid phosphatase (AP)). Both TA and TM caused accelerated hatching of the larvae. Under UV irradiation, there was greater mortality of the larvae of the groups exposed to TM, compared to those exposed to TA. Exposure to TM under UV irradiation altered the equilibrium of the larvae. Alterations in the activities of CAT and GST were indicative of oxidative stress, although no clear dose-response relationship was observed. The effects of nano-TiO2 appeared to depend on both the type of formulation and the illumination condition. The findings contribute to elucidation of the factors involved in the toxicity of these nanoparticles, as well as to the establishment of protocols for risk assessments of nanotechnology. PMID:24418748

Clemente, Z; Castro, V L S S; Moura, M A M; Jonsson, C M; Fraceto, L F

2014-02-01

110

Toxicity testing of leachate from waste landfills using medaka (Oryzias latipes) for monitoring environmental safety.  

PubMed

To investigate the environmental safety of waste disposal landfill sites and of land reclaimed from such sites, we evaluated the toxicity of leachate from these sites by a combination of bioassays in the Japanese killifish medaka Oryzias latipes. We tested for lethal toxicity in adult and larval medaka and for hatching inhibition of embryos from eggs. As biochemical evidence of the effects of leachate exposure, CYP1A (EROD activity) and vitellogenin (Vtg) were induced. We also bioassayed water-treated leachate and downstream river water. Leachate solution was lethal to larval and adult medaka. Embryo hatchability was inhibited, and abnormal hatching, spinal deformity and anisophthalmia occurred in embryos exposed to leachate solution. CYP1A was induced by exposure to leachate solution diluted to 1.0%, and EROD activity was significantly higher than in control. Vtg and unknown proteins were induced in the sera of male medaka exposed to the diluted leachate solution. Conventional water treatments worked effectively to remove toxic compounds but did not work well to remove element ions, including heavy metals. Treated leachate produced neither lethal toxicity nor hatching abnormalities during the exposure period. Fish toxicity tests for leachate would be useful for monitoring the environmental safety of landfill sites. PMID:16917699

Osaki, Kae; Kashiwada, Shosaku; Tatarazako, Norihisa; Ono, Yoshiro

2006-06-01

111

Toxicity of scorpion venom in chick embryo and mealworm assay depending on the use of the soluble fraction versus the whole venom.  

PubMed

The LD50 is an important metric for venom studies and antivenom development. It has been shown that several variables in the protocol influence the LD50 value obtained, such as venom source, extraction and treatment and administration route. These inconsistencies reduce the utility of the results of these test for comparative studies. In scorpion venom LD50 assays, often only the soluble fraction of the venom is used, whereas other studies use the whole venom. We here tested the toxicity of the soluble fraction in isolation, and of the whole venom in two different systems: chick embryos and mealworms Tenebrio molitor. Ten microliters of venom solutions from Hadrurus arizonensis, Leiurus quinquestriatus, Androctonus australis, Grosphus grandidieri and Heterometrus laoticus were applied to five day old chicken embryos at stage 25-27. Our results showed no significant differences between the LD50 based on the whole venom versus that of only the soluble fraction and in the chicken embryo assay in four of the five scorpion species tested. H. laoticus however, showed a significantly lower LD50 value for the whole venom than the soluble fraction. In assays on mealworms however, this pattern was not seen. Nonetheless, caution may be warranted when using LD50 values obtained from only the soluble fraction. The LD50 values of the five species in this study, based on the chicken embryo assay, showed good correlation with values from the literature based on mouse studies. This suggests that the chick embryo assay may be an economic alternative to rodent assays for scorpion LD50 studies. PMID:24951875

van der Valk, Tom; van der Meijden, Arie

2014-09-01

112

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

PubMed Central

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

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

2012-01-01

113

TOXIC SUBSTANCES CONTROL ACT TEST SUBMISSIONS (TSCATS)  

EPA Science Inventory

Toxic Substances Control Act Test Submissions (TSCATS) is an online index to unpublished, nonconfidential studies covering chemical testing results and adverse effects of chemicals on health and ecological systems. The studies are submitted by U.S. industry to EPA under several s...

114

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

NASA Astrophysics Data System (ADS)

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 ?m. 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.

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

2013-12-01

115

AhR2-mediated, CYP1A-independent cardiovascular toxicity in zebrafish (Danio rerio) embryos exposed to retene.  

PubMed

In the embryo-larval stages of fish, alkylphenanthrenes such as retene (7-isopropyl-1-methylphenanthrene) produce a suite of developmental abnormalities typical of exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), including pericardial and yolk sac edema, cardiovascular dysfunction, and skeletal deformities. To investigate the mechanism and target tissue of retene toxicity, we used observational, histological, and protein knockdown techniques in zebrafish (Danio rerio) embryos. The primary overt signs of toxicity are pericardial edema and reduced blood flow, first observed at 36 h post-fertilization (hpf). The most pronounced effects at this stage are a reduced layer of cardiac jelly in the atrium and reduced diastolic filling. Conversely, an increased layer of cardiac jelly is observed at 72 hpf in retene-exposed embryos. Induction of cytochrome P4501A (CYP1A) is apparent in a subset of cardiomyocytes by 48 hpf suggesting that early cardiac effects may be due to AhR activation in the myocardium. Myocardial CYP1A induction is transient, with only endocardial induction observed at 72 hpf. Knockdown of cyp1a by morpholino oligonucleotides does not affect retene toxicity; however, ahr2 knockdown prevents toxicity. Thus, the mechanism of retene cardiotoxicity is AhR2-mediated and CYP1A-independent, similar to TCDD; however, the onset and proximate signs of retene toxicity differ from those of TCDD. Retene cardiotoxicity also differs mechanistically from the cardiac effects of non-alkylated phenanthrane, illustrating that alkyl groups can alter toxic action. These findings have implications for understanding the toxicity of complex mixtures containing alkylated and non-alkylated polycyclic aromatic hydrocarbons. PMID:21040984

Scott, Jason A; Incardona, John P; Pelkki, Kathleen; Shepardson, Sally; Hodson, Peter V

2011-01-17

116

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

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. PMID:22562751

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

2012-08-01

117

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

SciTech Connect

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.

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

1988-04-01

118

Use of Japanese medaka (Oryzias latipes) and Tilapia (Oreochromis mossambicus) in toxicity tests on different industrial effluents in Taiwan.  

PubMed

In Taiwan, aquatic toxicity tests for industrial effluents are not required for discharge permits. However, relying on traditional chemical and physical characteristics of an effluent to monitor and regulate such discharges to manage water quality of a receiving water is insufficient. In this study, we used two fish species, Japanese medaka (Oryzias latipes) and tilapia (Oreochromis mossambicus), and three toxic endpoints, including acute and subacute toxicity, to determine toxicity of seven different types of industrial effluents. Prior to the study, two reference toxicants were tested on two fish species. The LC50s of CdCl2 for tilapia and medaka juveniles were 29.6 +/- 15.3 mg/L and 2.2 +/- 1.2 mg/L, respectively. The sensitivity of medaka embryo mortality and hatching inhibition to CdCl2 were about the same, with the LC50 and EC50 of 0.3 +/- 0.1 mg/L and 0.1 +/- 0.1 mg/L, respectively. The LC50s for tilapia and medaka juveniles to sodium dodecyl sulfate (SDS) were 19.7 +/- 10.6 mg/L and 12.5 +/- 5.9 mg/L. The medaka embryo was less sensitive to SDS than to CdCl2. The embryo's LC50 for SDS was 5.8 +/- 2.8 mg/L and the hatching inhibition EC50 was 1.3 +/- 1.1 mg/L. Results of toxicity tests on different effluents showed that the electroplating effluent was the most toxic, followed by acrylonitrile manufacturing and pulp/paper mill discharges. The LC50s of the electroplating effluent to different assays were in the range of several percents of the whole effluent. The pulp/paper effluent was toxic only to the medaka embryo. The rest of the industrial effluents tested showed either moderate or no toxicity to the animals. PMID:11443367

Chen, C M; Yu, S C; Liu, M C

2001-04-01

119

Quantitative structure-activity relationships for chronic toxicity of alkyl-chrysenes and alkyl-benz[a]anthracenes to Japanese medaka embryos (Oryzias latipes).  

PubMed

Alkylated polycyclic aromatic hydrocarbons (alkyl-PAHs) are a class of compounds found at significant concentrations in crude oils, and likely the main constituents responsible for the chronic toxicity of oil to fish. Alkyl substituents at different locations on the aromatic rings change the size and shape of PAH molecules, which results in different interactions with tissue receptors and different severities of toxicity. The present study is the first to report the toxicity of several alkylated derivatives of chrysene and benz[a]anthracene to the embryos of Japanese medaka (Oryzias latipes) using the partition controlled delivery (PCD) method of exposure. The PCD method maintained the desired exposure concentrations by equilibrium partitioning of hydrophobic test compounds from polydimethylsiloxane (PDMS) films. Test concentrations declined by only 13% over a period of 17 days. Based on the prevalence of signs of blue sac disease (BSD), as expressed by median effective concentrations (EC50s), benz[a]anthracene (B[a]A) was more toxic than chrysene. Alkylation generally increased toxicity, except at position 2 of B[a]A. Alkyl-PAHs substituted in the middle region had a lower EC50 than those substituted at the distal region. Except for B[a]A and 7-methylbenz[a]anthracene (7-MB), estimated EC50 values were higher than their solubility limits, which resulted in limited toxicity within the range of test concentrations. The regression between log EC50s and logKow values provided a rough estimation of structure-activity relationships for alkyl-PAHs, but Kow alone did not provide a complete explanation of the chronic toxicity of alkyl PAHs. PMID:25528422

Lin, Hongkang; Morandi, Garrett D; Brown, R Stephen; Snieckus, Victor; Rantanen, Toni; Jřrgensen, Kĺre B; Hodson, Peter V

2015-02-01

120

Contact tests for pentachlorophenol toxicity to earthworms  

SciTech Connect

The standardized contact filter paper test (EEC and OECD) provides an effective screening test for toxicity to earthworms in a laboratory setting. A need exists for a reliable and inexpensive technique for non-laboratory settings where screening is desired, but facilities cannot provide for the acquisition and maintenance of the glass vials required by the standardized test. This study evaluated two modifications of the standardized test using clear polyethylene bags, with and without filter paper, with Eisenia fetida and domesticated surface-feeding earthworms. The tests were conducted according to EEC and OECD guidelines. Results of the modified tests corresponded in dose and effect to the standardized contact filter paper test indicating the usefulness of the modified tests.

Spontak, D.A. [Utah State Univ., Logan, UT (United States)

1994-12-31

121

MAMMALIAN WILDLIFE (MINK AND FERRET) TOXICITY TEST PROTOCOLS (LC50, REPRODUCTION, AND SECONDARY TOXICITY)  

EPA Science Inventory

Protocols describing guidelines for conducting dietary LC50 and reproduction toxicity tests and for assessing the primary versus secondary toxicity of a test substance using carnivorous mammalian wildlife, specifically mink (Mustela vison) or European ferrets (Mustela putorius fu...

122

CHIRONOMIDAE TOXICITY TESTS--BIOLOGICAL BACKGROUND AND PROCEDURES  

EPA Science Inventory

Toxicity tests must be based on an understanding of the test animal's life cycle. The first section of this report describes the biological information needed to develop toxicity test procedures. The second section describes three categories of toxicity test systems - short-expos...

123

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

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. PMID:23510220

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

2012-01-01

124

Morphological development of testes in ostrich (Struthio camelus) embryo.  

PubMed

Although the histological structure of ostrich testis has been studied, very little information is currently available on the embryonic development of this organ. The aim of this study was to determine the sequence of the histological changes in diverse components of the testis in ostrich embryo from embryonic day (E) 20 to E42. The main findings were categorized into four histological features, i.e., development of sex cords, interstitial tissue and rete ducts, and the appearance of defective septa. While the lumen of sex cords, tunica albuginea, capsular rete ducts and Leydig cell precursors appeared at E26, the filum-shaped defective septa were visible at E36. The emersion of the lumen in the primary sex cords and formation of capsular rete ducts in the ostrich embryo is considerably different from that in other birds. However, tunica albuginea and Leydig cell precursors appeared in a similar pattern to those of other birds. An interesting observation was that the primordial germ cell (PGC)-like cells were completely distinct, while the capsular rete ducts were formed by trapping of some Sertoli cell aggregations in the tunica albuginea. This suggests that similar to the primary sex cords, the capsular rete ducts may originate from the Sertoli cell aggregations which had corralled some PGCs. Stereological estimations in the ostrich embryo testis showed the major proportion of testis is occupied by the seminiferous tubules, which is unlike the fowl embryo testis. PMID:24127229

Hassanzadeh, Belal; Nabipour, Abolghasem; Behnam Rassouli, Morteza; Dehghani, Hesam

2014-06-01

125

TOXICITY OF GUTHION AND GUTHION 2S TO XENOPUS LAEVIS EMBRYOS  

EPA Science Inventory

Differences in sensitivity to waterborne contaminants between wildlife species have prompted investigations on the sensitivity of amphibians to potentially hazardous environmental chemicals. he development of Xenopus laevis (African clawed frog) embryos exposed to the pesticide G...

126

The Red Tide Toxin, Brevetoxin, Induces Embryo Toxicity and Developmental Abnormalities  

NSDL National Science Digital Library

This Environmental Health Perspectives journal article documents a study on the relationship between brevetoxin, a toxin produced by red tide-related dinoflagellates, and abnormalities in fish embryos. The article features color photographs, charts, and tables.

Kimm-Brinson, Karen L.; Ramsdell, John S.; Perspectives, Environmental H.

127

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 ...

128

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

PubMed

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. PMID:24664821

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

2014-06-01

129

A novel one-pot green synthesis of selenium nanoparticles and evaluation of its toxicity in zebrafish embryos.  

PubMed

Over the last 50 years, compelling evidence has accumulated on the beneficial role of selenium in human health. In the present study, different proteins were evaluated as reducing agents for the eco-friendly synthesis of selenium nanoparticles from an aqueous solution of sodium selenite. This method is a simple, low cost green synthesis alternative to chemical synthesis. The high conversion of selenium ions to selenium nanoparticles (SeNPs) was achieved by a reaction mixture of 0.1 g bovine serum albumin and 0.1 g sodium selenite at a reaction temperature of 121°C for 20 min duration. The selenium nanoparticles were characterized by fourier transform infrared (FTIR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. The FTIR spectral bands were sharp with strong absorption peaks at 1649 and 1551 cm(- 1). SEM analysis of the synthesized selenium nanoparticles clearly showed the spherical shape with an average size ranging from 500 to 600 nm. The toxicity of SeNPs was evaluated using zebrafish embryos as a model system. SeNPs induced malformations in zebrafish embryos in a concentration-dependent manner. Selenium nanoparticles at 15-25 ?g/ml concentration caused pericardial edema, tail malformation and decrease in heart rate in zebrafish embryos. Treatments with lower concentrations did not alter the heart rate or display any heart abnormalities. This study underlines the importance of identifying optimal SeNP concentration that could have potential therapeutic applications. PMID:25287880

Kalishwaralal, Kalimuthu; Jeyabharathi, Subhaschandrabose; Sundar, Krishnan; Muthukumaran, Azhaguchamy

2014-10-01

130

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...

131

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

PubMed

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 ?L/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. PMID:25552345

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

2015-01-28

132

In situ acute/chronic toxicological monitoring of industrial effluents for the NPDES biomonitoring program using fish and amphibian embryo-larval stages as test organisms. Final report  

SciTech Connect

The Clean Water Act has necessitated further requirements and revisions in the industrial permit program maintained under the National Pollutant Discharge Elimination System (NPDES). It is now evident that in many cases the identification and control of toxic substances cannot be accomplished solely on the basis of an effluent guideline approach, emphasizing the need for reliable and economical procedures with which to quantify directly the net toxicity of complex effluents and estimate acute and chronic effects on aquatic biota. Therefore, the major objective of this investigation was to develop and evaluate fish and amphibian embryo-larval test procedures for the toxicogical characterization of municipal and industrial effluents.

Birge, W.J.; Black, J.A.

1981-09-01

133

Sand spiked with copper as a reference toxicant material for sediment toxicity testing: A preliminary evaluation  

SciTech Connect

Routine use of solid-phase sediment toxicity tests for scientific and regulatory purposes necessitates the development of solid-phase reference toxicant materials. In order to evaluate an approach for developing such materials, 12 solid-phase 96-h reference toxicant tests were conducted over 12 weeks with the marine bivalve Mulinia lateralis. Measured concentrations of copper in the water column above the reference material during testing showed that the toxicant exposures were relatively consistent between tests. Coefficients of variation (CV) for mortality and sublethality (growth) endpoints were 39% and 42%, respectively. (Copyright (c) 1994 Springer-Verlag New York Inc.)

Burgess, R.M.; Rogers, B.A.; Rego, S.A.; Corbin, J.M.; Morrison, G.E.

1994-01-01

134

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...

135

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

PubMed Central

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

Kimm-Brinson, K L; Ramsdell, J S

2001-01-01

136

Effect of pH on pentachlorophenol toxicity to embryos and larvae of zebrafish (Brachydanio rerio)  

SciTech Connect

The hydrogen ion is an important determinant of toxicity in the aquatic environment, especially for weak acids or bases. Pentachlorophenol is a weak acid and is consequently more toxic at low pH because of increasing proportions of free phenol. For some heavy metals the toxic interaction with ambient pH is complicated by complexation with organic and inorganic compounds. These complexes are affected by pH, and bioassays may be the easiest and most reliable method of determining the influence of pH in such cases. The objective of this study was to find a simple laboratory procedure for determination of the effect of pH on the toxicity of various chemicals added to or already present in various samples of ground and surface waters. Pentachlorophenol was selected as a reference toxicant and positive control because of its established pH-toxicity interaction in fish.

Dave, G.

1984-11-01

137

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

SciTech Connect

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 technical manuscript); (3) additional laboratory experimentation focused on the potential effects of long-term exposures to fly ash on fish survival and reproductive competence; and (4) a combined field and laboratory study examining the in vitro developmental success of embryos and larvae obtained from fish exposed in vivo for over two years to fly ash in the Emory and Clinch Rivers. These fish reproduction and early life-stage studies are being conducted in conjunction with a broader biological monitoring program administered by TVA that includes a field study of the condition of larval fish in the Emory and Clinch Rivers along with assessments of water quality, sediment composition, ecotoxicological studies, terrestrial wildlife studies, and human and ecological risk assessment. Information and data generated from these studies will provide direct input into risk assessment efforts and will also complement and help support other phases of the overall biomonitoring program. Fish eggs, in general, are known to be capable of concentrating heavy metals and other environmental contaminants from water-borne exposures during embryonic development (Jezierska and others 2009), and fathead minnow embryos in particular have been shown to concentrate methylmercury (Devlin 2006) as well as other chemical toxicants. This technical report focuses on the responses of fathead minnow embryos to simple contact exposures to fly ash in laboratory toxicity tests adapted from a standard fathead minnow (Pimephales promelas) 7-d embryo-larval survival and teratogenicity test (method 1001.0 in EPA 2002) with mortality, hatching success, and the incidences of developmental abnormalities as measured endpoints.

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

2012-05-01

138

A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations  

ERIC Educational Resources Information Center

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 studying embryo

Porntrai, Supaporn; Damrongphol, Praneet

2008-01-01

139

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...

140

Selenoneine, a novel selenium-containing compound, mediates detoxification mechanisms against methylmercury accumulation and toxicity in zebrafish embryo.  

PubMed

The selenium (Se)-containing antioxidant selenoneine (2-selenyl-N ?,N ?,N ?-trimethyl-L-histidine) has recently been discovered to be the predominant form of organic Se in tuna blood. Although dietary intake of fish Se has been suggested to reduce methylmercury (MeHg) toxicity, the molecular mechanism of MeHg detoxification by Se has not yet been determined. Here, we report evidence that selenoneine accelerates the excretion and demethylation of MeHg, mediated by a selenoneine-specific transporter, organic cations/carnitine transporter-1 (OCTN1). Selenoneine was incorporated into human embryonic kidney HEK293 cells transiently overexpressing OCTN1 and zebrafish blood cells by OCTN1. The K m for selenoneine uptake was 13.0 ?M in OCTN1-overexpressing HEK293 cells and 9.5 ?M in zebrafish blood cells, indicating high affinity of OCTN1 for selenoneine in human and zebrafish cells. When such OCTN1-expressing cells and embryos were exposed to MeHg-cysteine (MeHgCys), MeHg accumulation was decreased and the excretion and demethylation of MeHg were enhanced by selenoneine. In addition, exosomal secretion vesicles were detected in the culture water of embryos that had been microinjected with MeHgCys, suggesting that these may be responsible for MeHg excretion and demethylation. In contrast, OCTN1-deficient embryos accumulated MeHg, and MeHg excretion and demethylation were decreased. Furthermore, Hg accumulation was decreased in OCTN1-overexpressing HEK293 cells, but not in mock vector-transfected cells, indicating that selenoneine and OCTN1 can regulate MeHg detoxification in human cells. Thus, the selenoneine-mediated OCTN1 system regulates secretory lysosomal vesicle formation and MeHg demethylation. PMID:23709046

Yamashita, Michiaki; Yamashita, Yumiko; Suzuki, Tamami; Kani, Yoko; Mizusawa, Nanami; Imamura, Shintaro; Takemoto, Kenji; Hara, Tatsuro; Hossain, Md Anwar; Yabu, Takeshi; Touhata, Ken

2013-10-01

141

Toxicity of glyphosate as Glypro and LI700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.  

PubMed

More than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. Whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. In some instances, management of turtle habitat requires control of successional stages through application of herbicides. Adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through the soil. In the present study, we exposed eggs of red-eared sliders (Trachemys scripta elegans) to single applications of herbicide ranging from 0 to 11,206 ppm wet weight of glyphosate in Glypro and 0 to 678 ppm of the surfactant, LI700. Hatching success at the highest concentration was significantly lower (73%) than in other treatments (80-100%). At hatch, turtles at the highest concentration weighed less than those at other concentrations. During a 14-d holding period, we observed dose-response relationships in the ability of hatchlings to right themselves when turned on their backs. At the end of the holding period, hatchlings at the highest dose level were still lighter, and somatic indices were lower, than those in other treatments. Genetic damage, as measured by flow cytometry, increased with treatment concentration except for the highest dose. We conclude that because of the high concentrations needed to produce effects and the protection offered by several centimeters of soil or sediment, glyphosate with LI700 poses low levels of risk to red-eared slider embryos under normal field operations with regards to the endpoints measured in the present study. Carelessness in handling glyphosate or failure to follow label directions may produce adverse effects. There also is a risk that the health of turtle embryos may be affected in ways not measured in the present study. PMID:17022419

Sparling, Donald W; Matson, Cole; Bickham, John; Doelling-Brown, Paige

2006-10-01

142

Optimization of culturing conditions for toxicity testing with the alga Oophila sp. (Chlorophyceae), an amphibian endosymbiont.  

PubMed

Eggs of the yellow-spotted salamander (Ambystoma maculatum) have a symbiotic relationship with green algae. It has been suggested that contaminants that are preferentially toxic to algae, such as herbicides, may impair the symbiont and, hence, indirectly affect the development of the salamander embryo. To enable testing under near-standard conditions for first-tier toxicity screening, the authors isolated the alga from field-collected eggs and identified conditions providing exponential growth rates in the apparent asexual phase of the alga. This approach provided a uniform, single-species culture, facilitating assessment of common toxicity end points and comparison of sensitivity relative to other species. Sequencing of the 18s ribosomal DNA indicated that the isolated alga is closely related to the recently described Oophila amblystomatis but is more similar to other known Chlamydomonas species, suggesting possible biogeographical variability in the genetic identity of the algal symbiont. After a tiered approach to culturing method refinement, a modified Bristol's media with 1?mM NH4 (+) as nitrogen source was found to provide suitable conditions for toxicity testing at 18?°C and 200?µmol?m(-2) s(-1) photosynthetically active radiation (PAR) on a 24-h light cycle. The validity of the approach was demonstrated with Zn(2+) as a reference toxicant. Overall, the present study shows that screening for direct effects of contaminants on the algal symbiont without the presence of the host salamander is possible under certain laboratory conditions. PMID:25113146

Rodríguez-Gil, José Luis; Brain, Richard; Baxter, Leilan; Ruffell, Sarah; McConkey, Brendan; Solomon, Keith; Hanson, Mark

2014-11-01

143

Toxicity testing of trinitrotoluene-contaminated soil composts  

SciTech Connect

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.

Honeycutt, M.E. [TNRCC TARA, Austin, TX (United States); McFarland, V.A.; Jarvis, A.S. [USAEWES, Vicksburg, MS (United States)

1997-10-01

144

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 ...

145

STATUS AND APPLICATIONS OF ECHINOID (PHYLUM ECHINODERMATA) TOXICITY TEST METHODS  

EPA Science Inventory

The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrolus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). he status and relative sensitivity of various test methods are descri...

146

Temperature-based rapid toxicity test using Ceriodaphnia dubia.  

PubMed

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. PMID:16722086

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

2006-01-01

147

Toxicity of pristine graphene in experiments in a chicken embryo model  

PubMed Central

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 ?g/L, 100 ?g/L, 500 ?g/L, 1,000 ?g/L, 5,000 ?g/L, and 10,000 ?g/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 ?g/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. PMID:25152621

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

2014-01-01

148

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

SciTech Connect

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.

Carr, R.S.; Chapman, D.C.; Biedenbach, J.M.; Robertson, L. [NBS, Corpus Christi, TX (United States). NFCR Field Research Station

1994-12-31

149

Reference toxicants for toxicity testing using Caenorhabditis elegans in aquatic media  

SciTech Connect

Caenorhabditis elegans aquatic toxicity assays were standardized with five common reference toxicants: CdCl{sub 2}, NaCl, KCl, sodium lauryl sulfate (SLS), and sodium pentachlorophenate (PCP). Aquatic toxicity testing was conducted in 3 media: a standard C. elegans medium; EPA moderately hard reconstituted water; and EPA moderately hard mineral water. Test duration in each medium was 24h without a food source, and 24h and 48h with Escherichia coli strain OP50 as a food source. Each test was replicated three times with each replicate having 6 wells per concentration, 10 worms per well. LC{sub 50} values were calculated using probit analysis. The average LC{sub 50}s for each set of replications were compared to assess sensitivity and reproducibility of the data, identifying expected variation between replicate tests. These reference toxicants increase the database for C. elegans and provide a benchmark for further application.

Cressman, C.P. III; Williams, P.L. [Univ. of Georgia, Athens, GA (United States)

1997-09-01

150

INTRALABORATORY PRECISION OF SALTWATER SHORT-TERM CHRONIC TOXICITY TESTS  

EPA Science Inventory

Short-term chronic toxicity tests using five salt-water species-two fishes, a mysid, a sea urchin, and a macro-alga- were developed. opper sulfate and sodium dodecyl sulfate were used as representative toxicants. oefficients of variation for LC50 results ranged from 1.8 to 46.4%....

151

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

SciTech Connect

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.

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

1995-12-31

152

ESNATS conference - the use of human embryonic stem cells for novel toxicity testing approaches.  

PubMed

The main achievements and results of the ESNATS project (Embryonic Stem Cell-based Novel Alternative Testing Strategies) were presented at the final project conference that was held on 15 September 2013, the day before the traditional EUSAAT (European Society for Alternatives to Animal Testing) Congress in Linz, Austria. The ESNATS project was an FP7 European Integrated Project, running from 2008 to 2013, the aim of which was to develop a novel toxicity testing platform based on embryonic stem cells (ESCs), and in particular, human ESC (hESCs), to accelerate drug development, reduce related R&D costs, and propose a powerful alternative to animal tests in the spirit of the Three Rs principles. Altogether, ESNATS offered the first proof of concept that hESCs can be used to create robust, reproducible and ready-to-use test assays for predicting human toxicity. In the end, essentially five test systems were developed to an adequate level for entering possible pre-validation procedures. These methods are based on hESCs, and can be combined to study the possible effects, on the human embryo, of exposure to a chemical during the early stages of development. In addition to the presentations by the main project partners, external speakers were invited to give lectures on relevant topics, both in the field of neurotoxicity and, more generally, on the applicability of hESCs in the development of advanced in vitro tests. PMID:24901904

Rovida, Costanza; Vivier, Manon; Garthoff, Bernward; Hescheler, Jürgen

2014-05-01

153

The Bioaccumulation and Toxicity of Platinum Group Metals in Developing Chick Embryos  

NASA Astrophysics Data System (ADS)

Recent studies showed that platinum group metals (PGMs) such as Pt, Pd, and Rh from automobile catalytic converters, can accumulate in the soft tissues of a variety of living organisms. However, the effects of PGMs on bone and organs development of animals are not clearly understood. To examine these aspects, developing chick embryos were injected with 0.1, 1.0, 5, or 10 ppm solutions of Pt, Rh, Pd, or with a PGMs mixture. 1) Pathological Changes: were observed for all PGM treatments above 1 ppm. Bone Cells Assesment: Chondrocyte cells in thibiotarsus showed decreased diameter and length. 2) PGMs Accumulation in Tissues: was quantified by GFAAS spectrometry on finely ground tissue powder. 3) Bone Demineralization: was detected by micro-Raman spectroscopy imaging on paraffin embedded bone sections. 4) DNA Damage in Cells: was determined by using a Comet assay and fluorescence spectroscopy. Oxidative Damage in Tissues: was analyzed using a glutathione peroxidase assay. The overall results indicated that PGMs presence in our environment raises concerns about their long-term health effects on all organisms.

Pavel, Ioana; Monahan, Jennifer; Markopoulos, Marjorie; Gagnon, Zofia; Nejame, Britney; Cawley, Jacob; Reens, David

2008-10-01

154

Extrapolation of toxic indices among test objects  

PubMed Central

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

Tichý, Milo?; Rucki, Marián; Roth, Zden?k; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút

2010-01-01

155

Extrapolation of toxic indices among test objects.  

PubMed

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

Tichý, Milo?; Rucki, Marián; Roth, Zden?k; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút

2010-12-01

156

Bacterial and enzymatic bioassays for toxicity testing in the environment  

SciTech Connect

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.

Bitton, G.; Koopman, B. (Department of Environmental Engineering Sciences, University of Florida, Gainesville (United States))

1992-01-01

157

MANUAL FOR THE EVALUATION OF LABORATORIES PERFORMING AQUATIC TOXICITY TESTS  

EPA Science Inventory

This manual describes guidelines and standardized procedures for conducting on-site audits and evaluations of laboratories performing toxicity tests. ncluded are pre-survey information activities, on-site evaluation activities, evaluation criteria, organizational history and labo...

158

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....

159

DEVELOPMENT OF A SPERM CELL TOXICITY TEST FOR MARINE WATERS  

EPA Science Inventory

Preliminary methods for conducting a quick and sensitive sperm cell toxicity test for marine waters have been developed. This paper presents a simple static test in which sea urchin or sand dollar sperm cells are exposed to test or control solutions for short periods of time (typ...

160

Developmental toxicity of a commercial herbicide mixture in mice: I. Effects on embryo implantation and litter size.  

PubMed Central

We investigated the developmental toxicity in mice of a common commercial formulation of herbicide containing a mixture of 2,4-dichlorophenoxyacetic acid (2,4-D), mecoprop, dicamba, and inactive ingredients. Pregnant mice were exposed to one of four different doses of the herbicide mixture diluted in their drinking water, either during preimplantation and organogenesis or only during organogenesis. Litter size, birth weight, and crown-rump length were determined at birth, and pups were allowed to lactate and grow without additional herbicide exposure so that they could be subjected to additional immune, endocrine, and behavioral studies, the results of which will be reported in a separate article. At weaning, dams were sacrificed, and the number of implantation sites was determined. The data, although apparently influenced by season, showed an inverted or U-shaped dose-response pattern for reduced litter size, with the low end of the dose range producing the greatest decrease in the number of live pups born. The decrease in litter size was associated with a decrease in the number of implantation sites, but only at very low and low environmentally relevant doses. Fetotoxicity, as evidenced by a decrease in weight and crown-rump length of the newborn pups or embryo resorption, was not significantly different in the herbicide-treated litters. PMID:12417478

Cavieres, María Fernanda; Jaeger, James; Porter, Warren

2002-01-01

161

Development toxicity of functionalized single-walled carbon nanotubes on rare minnow embryos and larvae.  

PubMed

Abstract Carbon nanotubes (CNTs) are widely used in industrial and commercial applications, but few studies systematically evaluate their developmental toxicity on aquatic organism. Using rare minnow (Gobiocypris rarus) at early life stages as experimental models, developmental toxicity of functionalized single-walled CNTs (SWCNTs) was investigated following exposure to 0-320?mg/L for 144?h. Results revealed that significantly increased in mortality and malformation was only observed after hatching. Decreased body length, heart rate and swimming speed provide a concentration-dependent manner on larvae; values of 144?h LC50 and EC50 were 140.8 and 109.8?mg/L, respectively. Antioxidant enzyme activities (superoxide dismutase, catalase and glutathione S-transferase) and antioxidant enzyme related mRNA expressions were significant changed; cell apoptosis activities (caspase-3, -8, -9) and cell apoptosis related mRNA expressions were significant up-regulated; reactive oxygen species and DNA damage were significantly induced when the concentration of SWCNTs above 100?mg/L. Fluorescence and electron microscopy sliced observation show that SWCNTs were well dispersed in larvae within 0.5?h, eventually cleared from the larvae at 144?h. This is the first study to define uptake kinetics and to focus on behavioral consequences, physiological changes and mRNA expression following SWCNTs exposure in the early life stages of fish. The results obtained in the present study demonstrated that functionalized SWCNTs have the potential to affect aquatic life when released into the aquatic environment and reached high concentration. In the increasing economical context of SWCNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations. PMID:25211547

Zhu, Bin; Liu, Guang-Lu; Ling, Fei; Song, Lin-Sheng; Wang, Gao-Xue

2014-09-11

162

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

SciTech Connect

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.

Yeardley, R.B. Jr. [DynCorp-TAI, Cincinnati, OH (United States); Lazorchak, J.M. [Environmental Protection Agency, Cincinnati, OH (United States); Pence, M.A. [Technology Applications, Inc., Cincinnati, OH (United States)

1995-07-01

163

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

SciTech Connect

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.

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

1999-09-01

164

Evaluation of metals, metalloids, and ash mixture toxicity using sediment toxicity testing.  

PubMed

In December 2008, a release of 4.1 million m(3) of coal ash from the Tennessee Valley Authority Kingston Fossil Plant occurred. Ash washed into the Emory River and migrated downstream into the Clinch and Tennessee Rivers. A Baseline Ecological Risk Assessment evaluated risks to ecological receptors from ash in the river system post-dredging. This article describes the approach used and results from sediment toxicity tests, discussing any causal relationships between ash, metals, and toxicity. Literature is limited in the realm of aquatic coal combustion residue (CCR) exposures and the potential magnitude of effects on benthic invertebrates. Sediment samples along a spectrum of ash content were used in a tiered toxicity testing approach and included a combination of 10 day sediment toxicity acute tests and longer-term, partial life cycle "definitive" tests with 2 species (Hyalella azteca and Chironomus dilutus). Arsenic, and to a lesser extent Se, in the ash was the most likely toxicant causing observed effects in the laboratory toxicity tests. Sites in the Emory River with the greatest statistical and biologically significant effects had As concentrations in sediments twice the probable effects concentration of 33?mg/kg. These sites contained greater than 50% ash. Sites with less than approximately 50% ash in sediments exhibited fewer significant toxic responses relative to the reference sediment in the laboratory. The results discussed here present useful evidence of only limited effects occurring from a worst-case exposure pathway. These results provided a valuable line of evidence for the overall assessment of risks to benthic invertebrates and to other ecological receptors, and were crucial to risk management and development of project remediation goals. Integr Environ Assess Manag 2015;11:21-31. © 2014 SETAC. PMID:25125279

Stojak, Amber; Bonnevie, Nancy L; Jones, Daniel S

2015-01-01

165

Interpretation of reference toxicant tests in standard test procedures for sediment: How important are they?  

SciTech Connect

At SAIC`s Environmental Testing Center (ETC) 10-day solid-phase sediment toxicity tests using marine and estuarine amphipods are routinely conducted with a concurrent 96-hour water-only cadmium or sodium dodecyl sulfate (SDS) reference toxicant test and with a negative control sediment collected from central Long Island Sound (LIS). Reference toxicant tests are performed to evaluate test organism sensitivity. A negative control is used to evaluate laboratory ability to obtain consistent, precise results. Analysis of data from over 100 tests revealed that four situations may arise: results obtained from both the reference toxicant test and the negative control are acceptable; results from both are unacceptable; reference toxicant tests results are acceptable but negative control survival is not; and reference toxicant test results are unacceptable but negative control survival is acceptable. The latter case is of greatest interest during data interpretation. Analyses indicate that failed reference toxicant tests rarely affect interpretation of sediment test data. Therefore, the authors recommend that the use of reference toxicant tests be restricted to documentation of ongoing laboratory performance rather than interpretation of specific test results.

Mueller, C.A.; Thursby, G.B.; Schlekat, C.E.; Scott, K.J. [SAIC, Narragansett, RI (United States)

1994-12-31

166

Real-time in vivo imaging of size-dependent transport and toxicity of gold nanoparticles in zebrafish embryos using single nanoparticle plasmonic spectroscopy  

PubMed Central

Noble metal nanoparticles (NPs) show distinctive plasmonic optical properties and superior photostability, enabling them to serve as photostable multi-coloured optical molecular probes and sensors for real-time in vivo imaging. To effectively study biological functions in vivo, it is essential that the NP probes are biocompatible and can be delivered into living organisms non-invasively. In this study, we have synthesized, purified and characterized stable (non-aggregated) gold (Au) NPs (86.2 ± 10.8 nm). We have developed dark-field single NP plasmonic microscopy and spectroscopy to study their transport into early developing zebrafish embryos (cleavage stage) and their effects on embryonic development in real-time at single NP resolution. We found that single Au NPs (75–97 nm) passively diffused into the embryos via their chorionic pore canals, and stayed inside the embryos throughout their entire development (120 h). The majority of embryos (96 ± 3%) that were chronically incubated with the Au NPs (0–20 pM) for 120 h developed to normal zebrafish, while an insignificant percentage of embryos developed to deformed zebrafish (1 ± 1)% or dead (3 ± 3)%. Interestingly, we did not observe dose-dependent effects of the Au NPs (0–20 pM) on embryonic development. By comparing with our previous studies of smaller Au NPs (11.6 ± 0.9 nm) and similar-sized Ag NPs (95.4 ± 16.0 nm), we found that the larger Au NPs are more biocompatible than the smaller Au NPs, while the similar-sized Ag NPs are much more toxic than Au NPs. This study offers in vivo assays and single NP microscopy and spectroscopy to characterize the biocompatibility and toxicity of single NPs, and new insights into the rational design of more biocompatible plasmonic NP imaging probes. PMID:24427540

Browning, Lauren M.; Huang, Tao; Xu, Xiao-Hong Nancy

2013-01-01

167

Environmental toxicity testing of contaminated soil based on microcalorimetry.  

PubMed

Contaminated site assessment and monitoring requires efficient risk-management tools including innovative environmental toxicity tests. The first application of microcalorimetry for toxicity testing draw the attention to a possible new tool to increase sensitivity, to eliminate matrix effect and to study effect-mechanism. A Thermal Activity Monitor (TAM) microcalorimeter was used for measuring the heat production of various test organisms when getting in contact with sterile toxic soils. Well known bacterial (Azomonas agilis), animal (Folsomia candida) and plant test organisms (Sinapis alba) were tested for heat production. The heat response of selected testorganisms was measured in case of metal (Cu and Zn) and organic pollutant (Diesel oil, DBNPA and PCP) contaminated soils. In addition to the quantitative determination of the heat production, the mechanism of the toxic effect can be characterized from the shape of the power-time curve (slope of the curve, height and time of the maximum). In certain concentration ranges the higher the pollutant concentration of the soil the lower the maximum of the time-heat curve. At low pollutant concentrations an increased heat production was measured in case of A. agile and 20 and 200 mg Zn kg(-1) soil. The microcalorimetric testing was more sensitive in all cases than the traditional test methods. Our results showed that the microcalorimetric test method offers a new and sensitive option in environmental toxicology, both for research and routine testing. PMID:20549622

Gruiz, K; Feigl, V; Hajdu, Cs; Tolner, M

2010-10-01

168

Knockdown of AHR1A but not AHR1B exacerbates PAH and PCB-126 toxicity in zebrafish (Danio rerio) embryos  

PubMed Central

Various environmental contaminants are known agonists for the aryl hydrocarbon receptor (AHR), which is highly conserved across vertebrate species. Due to gene duplication events before and after the divergence of ray- and lobe-finned fishes, many teleosts have multiple AHR isoforms. The zebrafish (Danio rerio) has three identified AHRs: AHR1A and AHR1B, the roles of which are not yet well elucidated, and AHR2, which has been shown to mediate the toxicity of various anthropogenic compounds including dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). In this study, we sought to explore the role of the two AHR1 isoforms in PAH- and PCB-induced toxicity in zebrafish embryos utilizing morpholino gene knockdown of the AHR isoforms. Knockdown of AHR1B did not affect the toxicity of PAH mixtures or PCB-126, whereas knockdown of AHR1A exacerbated the cardiac toxicity caused by PAH mixtures and PCB-126. Knockdown of AHR1A did not impact the mRNA expression of CYP1A, CYP1B1, and CYP1C1 in exposed embryos, but it did result in increased CYP1 activity in exposed embryos. As has been shown previously, knockdown of AHR2 resulted in protection from PAH- and PCB-induced cardiac deformities and prevented CYP1 enzyme activity in exposed embryos. Co-knockdown of AHR1A and AHR2 resulted in an intermediate response compared to knockdown of AHR1A and AHR2 individually; co-knockdown did not exacerbate nor protect from PAH-induced deformities and embryos exhibited an intermediate CYP1 enzyme activity response. In contrast, co-knockdown of AHR1A and AHR2 did protect from PCB-126-induced deformities. These results suggest that AHR1A is not a nonfunctional receptor as previously thought and may play a role in the normal physiology of zebrafish during development and/or the toxicity of environmental contaminants in early life stages. PMID:24084256

Garner, Lindsey V.T.; Brown, Daniel R.; Giulio, Richard T. Di

2013-01-01

169

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...

170

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

PubMed

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 worms shortly after addition of Pb to soils may result in the over-estimate of Pb toxicity to worms. The current OECD acute worm toxicity test fails to take these two phenomena into account thereby reducing the environmental relevance of the contaminant toxicities it is used to calculate. PMID:12475061

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

2003-01-01

171

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

SciTech Connect

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.

Park, Margriet V.D.Z. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment, 3720 BA, Bilthoven (Netherlands); Department of Health Risk Analysis and Toxicology, Maastricht University, 6200 MD Maastricht (Netherlands)], E-mail: Margriet.Park@rivm.nl; Annema, Wijtske [Laboratory for Health Protection Research, National Institute for Public Health and the Environment, 3720 BA, Bilthoven (Netherlands); Salvati, Anna; Lesniak, Anna [Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4 (Ireland); Elsaesser, Andreas; Barnes, Clifford; McKerr, George; Howard, C. Vyvyan [Centre for Molecular Bioscience, University of Ulster, Coleraine, BT52 1SA (United Kingdom); Lynch, Iseult; Dawson, Kenneth A. [Centre for BioNano Interactions, School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4 (Ireland); Piersma, Aldert H. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment, 3720 BA, Bilthoven (Netherlands); Institute for Risk Assessment Sciences, University of Utrecht, 3508 TD, Utrecht (Netherlands); Jong, Wim H. de [Laboratory for Health Protection Research, National Institute for Public Health and the Environment, 3720 BA, Bilthoven (Netherlands)

2009-10-01

172

EVALUATION OF THE PEEP INDEX AND RECOMMENDED TOXICITY TESTS  

E-print Network

a Vancouver storm sewer. A flow-weighte~ composite sample from each site was tested for acute toxicity the mathematicalformula used to derive the index. A battery of bioassays is recommended for use in the FraserRiver Basin tliatthe SOS-Chromotest The test battery is identical to that used for the PEEP index, is replaced

173

GENETIC VARIATION FOR COPPER RESISTANCE IN FATHEAD MINNOW TOXICITY TESTS  

EPA Science Inventory

Unexplained variation in the results of aquatic organism toxicity tests is a consistently observed and troubling phenomenon. Possible sources of variation include differences in condition or nutritional status of the population prior to the test, as well as age, density and hand...

174

APPROPRIATE DURATIONS AND MEASURES FOR 'CERIODAPHNIA' TOXICITY TESTS  

EPA Science Inventory

The Mount-Norberg test, which employs a measure of the size of three broods over seven days, has been used extensively in toxicity testing. The authors have applied it to estimating sublethal ecosystem effects of complex effluents in the Raisin River drainage (of Michigan) on the...

175

Acute systemic toxicity—prospects for tiered testing strategies  

Microsoft Academic Search

After many years of controversy and debate, the LD50 test was finally deleted by the end of 2002. Three alternative animal tests, the Fixed Dose Procedure, the Acute Toxic Class Method and the Up and Down Procedure have been developed which give rise to significant improvements in animal welfare. They have recently undergone revision to improve their scientific performance but

P. A. Botham

2004-01-01

176

Improved bacterial growth test for rapid water toxicity screening  

Microsoft Academic Search

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

J. L. Slabbert

1986-01-01

177

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...

178

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

SciTech Connect

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

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

1987-08-01

179

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...

180

A COUPLED MICROSOMAL-ACTIVATING/EMBRYO CULTURE SYSTEM: TOXICITY OF REDUCED BETA-NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE (NADPH)  

EPA Science Inventory

An NADPH-dependent microsomal-activating system has been coupled to a rat embryo culture in vitro. No embryonic morphological abnormalities or decrease in final yolk sac or embryo DNA and protein contents occurred when 0.2 mM NADPH was used in this coupled system. In contrast, 1....

181

Eugenic selection benefits embryos.  

PubMed

The primary question to be addressed here is whether pre-implantation genetic diagnosis (PGD), used for both negative and positive trait selection, benefits potential supernumerary embryos. The phrase 'potential supernumerary embryos' is used to indicate that PGD is typically performed on a set of embryos, only some of which will be implanted. Prior to any testing, each embryo in the set is potentially supernumerary in the sense that it may not be selected for implantation. Those embryos that are not selected, and hence destroyed or frozen, are 'actually supernumerary'. The argument to be advanced is hypothetical: If embryos may be said to benefit or be harmed by our actions, then PGD used to select for an embryo or embryos with the highest expected Wellbeing benefits potential supernumerary embryos. The argument shows that the 'non-identity' problem is not sufficient to show that eugenic selection does not benefit supernumerary embryos. PMID:22845885

Walker, Mark

2014-06-01

182

Acute toxicity testing with the European estuarine amphipod Corophium multisetosum  

Microsoft Academic Search

This study reports on the use of the estuarine amphipod Corophium multisetosum in acute toxicity testing. The species was successfully acclimated to the laboratory and was used in a water-only whole effluent\\u000a 96 h acute bioassay and in a 10 days whole estuarine sediment test. C. multisetosum response was compared to other species in 96 h bioassays, testing boiling cork

Ana Ré; A. M. Rodrigues; V. Quintino

2007-01-01

183

REPORT ON ALGAL TOXICITY TESTS ON SELECTED OFFICE OF TOXIC SUBSTANCES (OTS) CHEMICALS  

EPA Science Inventory

Algal (Selenastrum capricornutum) assays were performed on 11 chemicals selected from a larger list of candidate chemicals provided by the EPA's Office of Toxic Substances (OTS). imited chemical analysis of those chemicals that could be tested readily at ERL-C was performed in su...

184

Toxicity of parathion on embryo and yolk-sac larvae of gilthead seabream (Sparus aurata l.): effects on survival, cholinesterase, and carboxylesterase activity.  

PubMed

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?ą) was about two-fold lower than the 48-h LC50 for embryos (1.005 mg L?ą). 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. PMID:19565633

Arufe, M Isabel; Arellano, Juana M; Albendín, Gemma; Sarasquete, Carmen

2010-12-01

185

Guidelines for developmental toxicity testing of chemicals in Japan  

SciTech Connect

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.

Tanimura, T.

1985-11-01

186

Differential effect of solar light in increasing the toxicity of silver and titanium dioxide nanoparticles to a fish cell line and zebrafish embryos.  

PubMed

The increasing use of silver (Ag) and titanium dioxide (TiO2) nanoparticles (NPs) in consumer products and their inevitable seepage into the environment prompted us to investigate their potential toxicity to a fish cell line (BF-2) and zebrafish embryos under dark and Simulated Solar Light (SSL) exposure conditions. Using high throughput screening (HTS) platforms, we showed that the oxidative stress-dependent cytotoxicity and embryonic toxicity of NPs were significantly increased upon exposure to SSL. While, the toxicity of TiO2 NPs under SSL exposure could be explained by hydroxyl radical generation, the enhanced toxicity of Ag NPs under SSL exposure was due to surface oxidation and physicochemical modification of Ag NPs and shedding of Ag+, leading to an increased bioavailability of silver. Our observations that solar light could induce physicochemical transformation of TiO2 and Ag NPs and enhance their toxic potential emphasizes the need for conducting future toxicity studies under environmentally relevant exposure conditions to guide decision making on the safe handling of NPs. PMID:24811346

George, Saji; Gardner, Hannah; Seng, Eng Khuan; Chang, Hengky; Wang, Chunyan; Yu Fang, Crystal Hay; Richards, Mark; Valiyaveettil, Suresh; Chan, Woon Khiong

2014-06-01

187

Functional toxicology: tools to advance the future of toxicity testing  

PubMed Central

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

Gaytán, Brandon D.; Vulpe, Chris D.

2014-01-01

188

Sun light mediated synthesis of gold nanoparticles as carrier for 6-mercaptopurine: Preparation, characterization and toxicity studies in zebrafish embryo model  

SciTech Connect

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.

Ganeshkumar, Moorthy [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India)] [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India); Sastry, Thotapalli Parvathaleswara [Bioproducts Laboratory, Central Leather Research Institute, Chennai 600020 (India)] [Bioproducts Laboratory, Central Leather Research Institute, Chennai 600020 (India); Sathish Kumar, Muniram [Department of Pharmaceutics, Anna University, Trichy, Tamilnadu (India)] [Department of Pharmaceutics, Anna University, Trichy, Tamilnadu (India); Dinesh, Murugan Girija [Thanthai Hansroever College, Perambalur, Tamilnadu (India)] [Thanthai Hansroever College, Perambalur, Tamilnadu (India); Kannappan, Sudalyandi [Central Institute of Brackish Water Aquaculture, Chennai 600028 (India)] [Central Institute of Brackish Water Aquaculture, Chennai 600028 (India); Suguna, Lonchin, E-mail: slonchin@yahoo.co.uk [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India)] [Department of Biochemistry, Central Leather Research Institute, Council of Scientific and Industrial Research, Chennai 600020 (India)

2012-09-15

189

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...

190

Controlling type-1 error rates in whole effluent toxicity testing  

SciTech Connect

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.

Smith, R.; Johnson, S.C. [EcoAnalysis, Inc., Ojai, CA (United States)

1995-12-31

191

Scanning respirometer for toxicity tests using micro-organisms  

NASA Astrophysics Data System (ADS)

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.

Zhang, Min-Quan; Li, Xiang-Ming; Wong, Yuk-Shan; Kwan, FolkYear

1995-09-01

192

Assessment of toxicity test endpoints for freshwater mussel larvae (glochidia).  

PubMed

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%. PMID:24122868

Fritts, Andrea K; Barnhart, M Christopher; Bradley, Megan; Liu, Na; Cope, W Gregory; Hammer, Edward; Bringolf, Robert B

2014-01-01

193

TOXICITY TEST USING LIFE STAGES OF 'CHAMPIA PARVULA' (RHODOPHYTA)  

EPA Science Inventory

A static-renewal, 11- to 14-day toxicity test has been developed using the life cycle of the marine red alga Champia parvula (C. Ag.) Harv. It measures the vegetative growth, formation of tetrasporangia (meiosis), and formation of cystocarps (sexual fusion). The procedure has bee...

194

COMPUTER INTERFACED TOXICITY TESTING SYSTEM FOR SIMULATING VARIABLE EFFLUENT LOADING  

EPA Science Inventory

Water quality criteria and standards are based primarily on toxicity tests carried out with single chemicals whose concentration is as nearly constant as possible. In the 'real world', however, organisms are exposed to mixtures of chemicals which usually have markedly fluctuating...

195

Aquatic toxicity tests for the control of effluent discharges in the UK — the influence of test precision  

Microsoft Academic Search

The initiative by the River Purification Boards (RPBs), National Rivers Authority (NRA) and Her Majesty's Inspectorate of Pollution (HMIP) to control certain complex and toxic effluent discharges by direct toxicity assessment places great emphasis on the use of aquatic toxicity tests. Like all biological and analytical measurements, determinations of toxicity exhibit variability. When setting ‘Toxicity-based Consents’ (TBCs) and monitoring for

Paul Whitehouse; Mark Crane; C. John Redshaw; Craig Turner

1996-01-01

196

Use of DNA strand damage (Comet assay) and embryo hatching effects to assess contaminant exposure in blue crab (Callinectes sapidus) embryos  

SciTech Connect

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.

Lee, R.F.; Steinert, S.A.; Nakayama, K.; Oshima, Y.

1999-07-01

197

Effect of test conditions on relative toxicity rankings of fifteen materials  

NASA Technical Reports Server (NTRS)

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.

Hilado, C. J.; Cumming, H. J.

1977-01-01

198

Insect (Locusta migratoria migratorioides) test monitoring the toxicity of cyanobacteria.  

PubMed

An insect test was developed to investigate the toxicity of cyanobacteria. The African locust, Locusta migratoria migratorioides R.F. was used as a test animal instead of mouse. The cyanobacteria tested were Aphanizomenon flos-aque, Anabaena aphanizomenoides, Cylindrospermopsis raciborskii, Microcystis aeruginosa. The toxicity of authentic microcystin-LR was also tested. Cyanobacteria producing toxins killed the animals when the homogenized cell suspension was injected into the animals. The locust test proved to be more sensitive than the mouse test. The LD50 values of the different cyanobacteria for locusts and for mice, respectively were the following: 90 microg/animal (60 mg/kg) and 8000 microg/animal (320 mg/kg), for Aphanizomenon flos-aquae; 255 microg/animal (170.2 mg/kg) and 3750 microg/animal (150 mg/kg), for Anabaena aphanizomenoides; 195 microg/animal (131.4 mg/kg) and 5750 microg/animal (230 mg/kg), for Cylindrospermopsis raciborskii; 22.5 microg/animal (15 mg/kg) and 6000 microg/ animal (240 mg/kg), for Microcystis aeruginosa. In locusts the LD50 value for authentic microcystin-LR was 0.2 microg/animal (130 mg/kg). Since the weight of the mice is 15 to 20 times larger than that of the locusts, hence less toxic cells are needed to kill the locusts. The locust test is cheaper than the mouse test, large number of animals can be used in the experiments and the LD50 values can be estimated more precisely. The toxicity of C. raciborskii was significantly lower when the lyophilized cells were extracted in methanol (LD50 = 767 mg/kg), instead of NaCl solution (LD50 = 131.4 mg/kg). PMID:9745918

Hiripi, L; Nagy, L; Kalmár, T; Kovács, A; Vörös, L

1998-01-01

199

EP-toxicity testing of mercury removal resin grout  

SciTech Connect

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.

Mersman, K.E.

1984-07-18

200

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing  

PubMed Central

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to model well differentiated human airway epithelium and heart muscle cells. This could be an invaluable tool to study the deleterious effects of toxic inhaled chemicals, such as chlorine, that can normally interact with the cell surfaces, and form various byproducts upon reacting with water, and limiting their effects in submerged cultures. Our model using well differentiated human airway epithelial cell cultures at air-liqiuid interface circumvents this limitation as well as provides an opportunity to evaluate critical mechanisms of toxicity of potential poisonous inhaled chemicals. We describe enhanced loss of membrane integrity, caspase release and death upon toxic inhaled chemical such as chlorine exposure. In this article, we propose methods to model chlorine exposure in mammalian heart and airway epithelial cells in culture and simple tests to evaluate its effect on these cell types. PMID:24837339

Ahmad, Shama; Ahmad, Aftab; Neeves, Keith B.; Hendry-Hofer, Tara; Loader, Joan E.; White, Carl W.; Veress, Livia

2014-01-01

201

In vitro cell culture model for toxic inhaled chemical testing.  

PubMed

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to model well differentiated human airway epithelium and heart muscle cells. This could be an invaluable tool to study the deleterious effects of toxic inhaled chemicals, such as chlorine, that can normally interact with the cell surfaces, and form various byproducts upon reacting with water, and limiting their effects in submerged cultures. Our model using well differentiated human airway epithelial cell cultures at air-liqiuid interface circumvents this limitation as well as provides an opportunity to evaluate critical mechanisms of toxicity of potential poisonous inhaled chemicals. We describe enhanced loss of membrane integrity, caspase release and death upon toxic inhaled chemical such as chlorine exposure. In this article, we propose methods to model chlorine exposure in mammalian heart and airway epithelial cells in culture and simple tests to evaluate its effect on these cell types. PMID:24837339

Ahmad, Shama; Ahmad, Aftab; Neeves, Keith B; Hendry-Hofer, Tara; Loader, Joan E; White, Carl W; Veress, Livia

2014-01-01

202

COMPARISON AND EVALUATION OF FIELD AND LABORATORY TOXICITY TESTS WITH FENVALERATE ON AN ESTUARINE CRUSTACEAN  

EPA Science Inventory

A combination of laboratory toxicity tests was conducted on the grass shrimp, Palaemonetes pugio. est results were compared with field toxicity tests to evaluate the usefulness of laboratory testing in estimating mortality from fenvalerate exposure associated with agricultural ru...

203

Modulation of cupric ion activity by pH and fulvic acid as determinants of toxicity in Xenopus laevis embryos and larvae  

SciTech Connect

An ion-specific electrode measured cupric ion activity modulated by fulvic acid (FA) and pH in a series of modified Frog Embryo Teratogenesis Assay--Xenopus (FETAX) toxicity assays. Hydrogen ion concentration was the primary determinant of cupric ion activity, while FA played a smaller but significant role. Fulvic acid was a weak copper complexing agent at pH 5.50. At pH 5.50 there was slight reduction of ionic activity and a subsequent attenuation of copper toxicity with 5.0 mg/L FA. At pH 7.50, FA also had a mild attenuating effect on copper toxicity. At pH 6.50, copper was strongly complexed by FA at total copper (TCu) concentrations below its pH-dependent solubility limit. At TCu concentrations above the solubility limit FA enhanced toxicity. There was more cupric ion activity measured in the presence of 0.5 and 5.0 mg/L FA than without it at TCu concentrations above the solubility limit. The proposed mechanism for this behavior was FA action as a nucleation inhibitor. Under the chemical conditions of the pH 6.50 experiments, a stable supersaturation of copper was formed, resulting in a more toxic aqueous matrix.

Buchwalter, D.B. [Oregon State Univ., Corvallis, OR (United States). Toxicology Program]|[ManTech Environmental Technology, Inc., Corvallis, OR (United States); Linder, G. [ManTech Environmental Technology, Inc., Corvallis, OR (United States); Curtis, L.R. [East Tennessee State Univ., Johnson City, TN (United States). Dept. of Environmental Health

1996-04-01

204

Normal Calves Obtained after Direct Transfer of Vitrified Bovine Embryos Using Ethylene Glycol, Trehalose, and Polyvinylpyrrolidone  

Microsoft Academic Search

In the present study, IVF bovine embryos were vitrified using as the cryoprotectants, ethylene glycol plus trehalose plus the polymer, polyvinylpyrrolidone (PVP). In Experiment I, toxicity of the vitrification solution (VS) containing 20% PVP was tested in relation to temperature and exposure time. One hundred percent embryo development was observed with treatment at 5°C for 5 min, whereas only 55.5%

S. SAHA; T. OTOI; M. TAKAGI; A. BOEDIONO; C. SUMANTRI; T. SUZUKI

1996-01-01

205

Decreased Dissolution of ZnO by Iron Doping Yields Nanoparticles with Reduced Toxicity in the Rodent Lung and Zebrafish Embryos  

PubMed Central

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

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

206

In situ toxicity testing with locally collected Daphnia  

SciTech Connect

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.

Snyder-Conn, E.

1993-07-01

207

Toxicity testing and instream biological monitoring in evaluating municipal effluents  

SciTech Connect

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.

Krier, K.; Pontasch, K. [Univ. of Northern Iowa, Cedar Falls, IA (United States). Environmental Science Program

1995-12-31

208

Evaluation of the test of significant toxicity for determining the toxicity of effluents and ambient water samples.  

PubMed

The test of significant toxicity (TST) is a hypothesis-testing approach based on bioequivalence developed by the U.S. Environmental Protection Agency (U.S. EPA) for analyzing whole-effluent toxicity (WET) and ambient toxicity data. The present study compares results of acute and chronic toxicity tests of effluent, storm-water, and ambient (i.e., receiving-water) samples using both the TST and the standard no-observed-effect concentration (NOEC) approach. Valid WET data were analyzed from 890 tests provided by more than 25 dischargers in California and Washington, USA, representing the majority of test methods used in the U.S. WET program. An additional 3,201 freshwater chronic toxicity tests, obtained from ambient monitoring programs in California, were also analyzed. The TST and NOEC approaches both declared a low number (<6.5%) of tests toxic if effects were below the unacceptable toxicity regulatory management decision (RMD) of 25% effect in chronic tests or 20% effect in acute tests. However, those test methods having generally lower within-test variability and greater test power (e.g., urchin fertilization test) had a much lower percentage of tests declared toxic than the NOEC approach when effects were below the unacceptable toxicity RMD. In addition, the TST showed fewer tests to be nontoxic than NOEC if the test exhibited effects greater than the toxicity RMD (0.1 and 9.6% for TST and NOEC, respectively, for effluents and 0 and 9.5%, respectively, for ambient samples). Our results demonstrate that the TST is more likely to identify a toxic sample when effects are fairly substantial (? 25% effect in chronic testing and ? 20% effect in acute tests) and less likely to identify a sample as toxic when effects are negligible (? 10% effect). Furthermore, these results demonstrate that appropriate WET data interpretation benefits from having well-designed test methods with sufficient power to identify significant toxicity or biologically insignificant effects when they occur. PMID:23400869

Diamond, Jerry M; Denton, Debra L; Roberts, John W; Zheng, Lei

2013-04-01

209

Sulfidation as a Natural Antidote to Metallic Nanoparticles Is Overestimated: CuO Sulfidation Yields CuS Nanoparticles with Increased Toxicity in Medaka (Oryzias latipes) Embryos.  

PubMed

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. PMID:25625586

Li, Lingxiangyu; Hu, Ligang; Zhou, Qunfang; Huang, Chunhua; Wang, Yawei; Sun, Cheng; Jiang, Guibin

2015-02-17

210

Toxicogenomic responses of zebrafish embryos/larvae to tris(1,3-dichloro-2-propyl) phosphate (TDCPP) reveal possible molecular mechanisms of developmental toxicity.  

PubMed

Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is frequently present in indoor dust and can be detected in human milk. In order to evaluate the effects of TDCPP on vertebrate development, zebrafish embryos/larvae were used as an animal model to examine developmental phenotypes and explore possible mechanisms of toxicity by employing microarrays and iTRAQ labeling quantitative proteomics. The results demonstrated that treatment with TDCPP (3 ?M) from 0.75 h postfertilization (hpf) inhibited cell rearrangement at 4 hpf, caused delay in epiboly at 5.7 and 8.5 hpf, and led to abnormal development (e.g., short tail, reduced body size) and lethality between 14 and 45 hpf, which might be related with altered expression of genes regulating embryogenesis. Furthermore, trunk curvature was observed as the main phenotype in 96 hpf zebrafish larvae exposed to 1 or 3 ?M TDCPP, possibly by changing somite formation and expression of proteins related to fast muscle and cartilage development. Collectively, our results suggest that exposure to TDCPP causes developmental toxicity in vertebrates and warrant the need for studies to evaluate the potential health risks of TDCPP to developing human embryos/infants/children, due to its frequent presence in indoor dust and potential for human exposure. PMID:23919627

Fu, Jie; Han, Jian; Zhou, Bingsheng; Gong, Zhiyuan; Santos, Eduarda M; Huo, Xiaojing; Zheng, Weiling; Liu, Hongling; Yu, Hongxia; Liu, Chunsheng

2013-09-17

211

Genotoxic and teratogenic effect of freshwater sediment samples from the Rhine and Elbe River (Germany) in zebrafish embryo using a multi-endpoint testing strategy.  

PubMed

The embryotoxic potential of three model sediment samples with a distinct and well-characterized pollutant burden from the main German river basins Rhine and Elbe was investigated. The Fish Embryo Contact Test (FECT) in zebrafish (Danio rerio) was applied and submitted to further development to allow for a comprehensive risk assessment of such complex environmental samples. As particulate pollutants are constructive constituents of sediments, they underlay episodic source-sink dynamics, becoming available to benthic organisms. As bioavailability of xenobiotics is a crucial factor for ecotoxicological hazard, we focused on the direct particle-exposure pathway, evaluating throughput-capable endpoints and considering toxicokinetics. Fish embryo and larvae were exposed toward reconstituted (freeze-dried) sediment samples on a microcosm-scale experimental approach. A range of different developmental embryonic stages were considered to gain knowledge of potential correlations with metabolic competence during the early embryogenesis. Morphological, physiological, and molecular endpoints were investigated to elucidate induced adverse effects, placing particular emphasis on genomic instability, assessed by the in vivo comet assay. Flow cytometry was used to investigate the extent of induced cell death, since cytotoxicity can lead to confounding effects. The implementation of relative toxicity indices further provides inter-comparability between samples and related studies. All of the investigated sediments represent a significant ecotoxicological hazard by disrupting embryogenesis in zebrafish. Beside the induction of acute toxicity, morphological and physiological embryotoxic effects could be identified in a concentration-response manner. Increased DNA strand break frequency was detected after sediment contact in characteristic non-monotonic dose-response behavior due to overlapping cytotoxic effects. The embryonic zebrafish toxicity model along with the in vivo comet assay and molecular biomarker analysis should prospectively be considered to assess the ecotoxicological potential of sediments allowing for a comprehensive hazard ranking. In order to elucidate mode of action, novel techniques such as flow cytometry have been adopted and proved to be valuable tools for advanced risk assessment and management. PMID:25471716

Garcia-Käufer, M; Gartiser, S; Hafner, C; Schiwy, S; Keiter, S; Gründemann, C; Hollert, H

2014-12-01

212

Fluorescent cell-based sensing approaches for toxicity testing  

Microsoft Academic Search

Fluorimetric cell-based sensing methods have attracted increasing interest in toxicity testing of pharmaceuticals, pathogens,\\u000a environmental pollutants, and other chemicals. The objective of this review is to summarise the variety of approaches reported\\u000a up to now and to present recent developments in this area. The different approaches are described in relation to their underlying\\u000a mechanism and, especially, to the role of

Michael Fritzsche; Carl-Fredrik Mandenius

2010-01-01

213

Bioavailability of fluoranthene in freshwater sediment toxicity tests  

SciTech Connect

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.

Suedel, B.C.; Rodgers, J.H. Jr. (Univ. of Mississippi, University (United States)); Clifford, P.A. (EA Engineering Science and Technology, Inc., Sparks, MD (United States))

1993-01-01

214

FISH SUBCHRONIC TOXICITY PREDICTION MODEL FOR INDUSTRIAL ORGANIC CHEMICALS THAT PRODUCE NARCOSIS  

EPA Science Inventory

A model based on partition coefficient was developed for predicting subchronic toxicities of selected chemicals to fish. Early life stage tests were conducted under flow-through conditions using fathead minnows (Pimephales promelas) as test organisms. Embryos, larvae and juvenile...

215

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

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. PMID:25391229

Thellmann, Paul; Köhler, Heinz-R; Rößler, Annette; Scheurer, Marco; Schwarz, Simon; Vogel, Hans-Joachim; Triebskorn, Rita

2014-11-13

216

FETAX interlaboratory validation study: Phase 2 testing  

Microsoft Academic Search

The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that

John A. Bantle; Dennis T. Burton; Douglas A. Dawson; James N. Dumont; Robert A. Finch; Douglas J. Fort; Greg Linder; James R. Rayburn; David Buchwalter; Angela M. Gaudet-Hull; Margaret A. Maurice; Steven D. Turley

1994-01-01

217

Study of Charge-Dependent Transport and Toxicity of Peptide-Functionalized Silver Nanoparticles Using Zebrafish Embryos and Single Nanoparticle Plasmonic Spectroscopy  

PubMed Central

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+?), negatively (Ag-CALNNS NPs?2?), and more negatively charged NPs (Ag-CALNNE NPs?4?), 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+? (positively charged) are the most biocompatible while the Ag-CALNNE NPs–4? (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 in vivo and in tissues, and reveals the possibility of rational design of biocompatible NPs. PMID:23621491

Lee, Kerry J.; Browning, Lauren M.; Nallathamby, Prakash D.; Xu, Xiao-Hong Nancy

2013-01-01

218

Sediment toxicity testing of Lake Orta after liming  

SciTech Connect

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.

Baudo, R.; Beltrami, M.; Rossi, D. [CNR, Verbania-Pallanza (Italy). Ist. Italiano Idrobiologia; Gronda, A. [Ecotox LSD, Prenana Milanese (Italy); Abdel-Monem, A.M. [National Institutes of Oceanography and Fisheries, Cairo (Egypt); Burton, G.A. [Wright State Univ., Dayton, OH (United States)

1995-12-31

219

The environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin disrupts morphogenesis of the rat pre-implantation embryo  

PubMed Central

Background Environmental toxicants, whose actions are often mediated through the aryl hydrocarbon receptor (AhR) pathway, pose risks to the health and well-being of exposed species, including humans. Of particular concern are exposures during the earliest stages of development that while failing to abrogate embryogenesis, may have long term effects on newborns or adults. The purpose of this study was to evaluate the effect of maternal exposure to the AhR-specific ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development of rat pre-implantation embryos with respect to nuclear and cytoskeletal architecture and cell lineage allocation. Results We performed a systematic 3 dimensional (3D) confocal microscopy analysis of rat pre-implantation embryos following maternal exposure to environmentally relevant doses of TCDD. Both chronic (50 ng/kg/wk for 3 months) and acute (50 ng/kg and 1 ?g/kg at proestrus) maternal TCDD exposure disrupted morphogenesis at the compaction stage (8–16 cell), with defects including monopolar spindle formation, f-actin capping and fragmentation due to aberrant cytokinesis. Additionally, the size, shape and position of nuclei were modified in compaction stage pre-implantation embryos collected from treated animals. Notably, maternal TCDD exposure did not compromise survival to blastocyst, which with the exception of nuclear shape, were morphologically similar to control blastocysts. Conclusion We have identified the compaction stage of pre-implantation embryogenesis as critically sensitive to the effects of TCDD, while survival to the blastocyst stage is not compromised. To the best of our knowledge this is the first in vivo study to demonstrate a critical window of pre-implantation mammalian development that is vulnerable to disruption by an AhR ligand at environmentally relevant doses. PMID:18171477

Hutt, Karla J; Shi, Zhanquan; Albertini, David F; Petroff, Brian K

2008-01-01

220

Tritium toxicity: age-dependent radiosensitivity of mouse testes  

SciTech Connect

As a radiation hazard of biological significance tritium has largely been ignored because of its rapid turnover from the body, its low average beta energy, and short range in the tissue. In all the available reports of the investigations, little research effort has been noticed on the age-specific consequences of HTO-irradiation of mammals in the perinatal to pubertal stages of life as compared to the adult stages. The present study is an attempt to evaluate qualitative and quantitatively the age dependent radio-sensitivity of mice testes to tritium toxicity.

Bhatia, A.L.

1985-06-01

221

Evaluation of a phytoplankton toxicity test for water pollution assessment and control  

Microsoft Academic Search

A suggested standard test protocol for the short term14C assimilation algal toxicity test method (photosynthesis inhibition test) has been evaluated with natural phytoplankton and cultures of the marine diatomSkeletonema costatum. A number of test technical factors as well as the variability in the sensitivity of natural phytoplankton have been investigated, using potassium dichromate as a reference toxicant in all tests.

Kresten Ole Kusk; Niels Nyholm

1991-01-01

222

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...

223

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...

224

Toxicity testing of organic chemicals in groundwater polluted with landfill leachate  

SciTech Connect

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.

Baun, A.; Kloeft, L.; Bjerg, P.L.; Nyholm, N.

1999-09-01

225

Evaluation of municipal waste incinerator fly ash toxicity and the role of cadmium by two aquatic toxicity tests  

SciTech Connect

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.

Kaneko, Hidehiro [Yamanashi Univ., Kofu, Yamanashi (Japan). Dept. of Civil and Environmental Engineering] [Yamanashi Univ., Kofu, Yamanashi (Japan). Dept. of Civil and Environmental Engineering

1996-12-31

226

Combined repeated-dose toxicity study of silver nanoparticles with the reproduction/developmental toxicity screening test.  

PubMed

Combined repeated-dose toxicity study of citrate-capped silver nanoparticles (7.9 ± 0.95 nm) with reproduction/developmental toxicity was investigated in rats orally treated with 62.5, 125 and 250 mg/kg, once a day for 42 days for males and up to 52 days for females. The test was performed based on the Organization for Economic Cooperation and Development test guideline 422 and Good Laboratory Practice principles. No death was observed in any of the groups. Alopecia, salivation and yellow discolouration of the lung were observed in a few rats but the symptoms were not dose-dependent. Haematology, serum biochemical investigation and histopathological analysis revealed no statistically significant differences between control group and the treated groups. Toxicity endpoints of reproduction/developmental screening test including mating, fertility, implantation, delivery and foetus were measured. There was no evidence of toxicity. PMID:23432083

Hong, Jeong-Sup; Kim, Suhyon; Lee, Sang Hee; Jo, Eunhye; Lee, Byungcheun; Yoon, Junheon; Eom, Ig-Chun; Kim, Hyun-Mi; Kim, Pilje; Choi, Kyunghee; Lee, Moo Yeol; Seo, Yeong-Rok; Kim, Younghun; Lee, Yeonjin; Choi, Jonghye; Park, Kwangsik

2014-06-01

227

Comparative toxicity of diuron on survival and growth of Pacific treefrog, bullfrog, red-legged frog, and African clawed frog embryos and tadpoles.  

PubMed

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 embryos had reduced growth and developed increased deformities in diuron concentrations over 20 mg/L. Hindlimb bud and forelimb development were retarded in R. aurora following 14 days exposure to diuron concentrations of > 7.6 mg/L. Mean 14-day LC50s for P. regilla and X. laevis tadpoles were 15.2 and 11.3 mg/L diuron, respectively. The 21-day LC50 for R. catesbeiana tadpoles was 12.7 mg/L diuron. The 14-day LC50 for R. aurora tadpoles was 22.2 mg/L. The lowest NOAELs calculated in embryo tests were 14.5 mg/L for P. regilla (10 days) and 7.6 mg/L diuron for X. laevis (4 days). The lowest NOAELs calculated in tadpole tests were: P. regilla, 14.5 mg/L (14 days); R. catesbeiana, 7.6 mg/L (21 days); R. aurora, 7.6 mg/L (14 days); and X. laevis, > 29.1 mg/L (14 days). Diuron concentrations having an effect on survival, growth, and malformation in the laboratory were much higher than those found in normal field spray situations; field studies would be needed to determine the hazard to amphibians in areas of localized pooling of recently applied herbicide in the environment. PMID:9543507

Schuytema, G S; Nebeker, A V

1998-05-01

228

Test of significant toxicity: a statistical application for assessing whether an effluent or site water is truly toxic.  

PubMed

The U.S. Environmental Protection Agency (U.S. EPA) and state agencies implement the Clean Water Act, in part, by evaluating the toxicity of effluent and surface water samples. A common goal for both regulatory authorities and permittees is confidence in an individual test result (e.g., no-observed-effect concentration [NOEC], pass/fail, 25% effective concentration [EC25]), which is used to make regulatory decisions, such as reasonable potential determinations, permit compliance, and watershed assessments. This paper discusses an additional statistical approach (test of significant toxicity [TST]), based on bioequivalence hypothesis testing, or, more appropriately, test of noninferiority, which examines whether there is a nontoxic effect at a single concentration of concern compared with a control. Unlike the traditional hypothesis testing approach in whole effluent toxicity (WET) testing, TST is designed to incorporate explicitly both ? and ? error rates at levels of toxicity that are unacceptable and acceptable, given routine laboratory test performance for a given test method. Regulatory management decisions are used to identify unacceptable toxicity levels for acute and chronic tests, and the null hypothesis is constructed such that test power is associated with the ability to declare correctly a truly nontoxic sample as acceptable. This approach provides a positive incentive to generate high-quality WET data to make informed decisions regarding regulatory decisions. This paper illustrates how ? and ? error rates were established for specific test method designs and tests the TST approach using both simulation analyses and actual WET data. In general, those WET test endpoints having higher routine (e.g., 50th percentile) within-test control variation, on average, have higher method-specific ? values (type I error rate), to maintain a desired type II error rate. This paper delineates the technical underpinnings of this approach and demonstrates the benefits to both regulatory authorities and permitted entities. PMID:21305584

Denton, Debra L; Diamond, Jerry; Zheng, Lei

2011-05-01

229

Quantification and in situ localisation of abcb1 and abcc9genes in toxicant-exposed sea urchin embryos.  

PubMed

A multixenobiotic resistance (MXR) mechanism mediated by ABC binding cassette (ABC) transport proteins is an efficient chemical defence mechanism in sea urchin embryos. The aim of our work was to evidence whether exposure to sub-lethal doses of specific contaminants (oxybenzone (OXI), mercuric chloride (HgCl2) and trybutiltin (TBT)) would induce MXR transporter activity during embryonic development (from zygote to blastula stage) in purple sea urchin (Paracentrotus lividus) embryos. Further, we present data on molecular identification, transport function, expression levels and gene localisation of two ABC efflux transporters-P-glycoprotein (ABCB1/P-gp) and sulfonylurea-receptor-like protein (ABCC9/SUR-like). Partial cDNA sequences of abcb1 and abcc9 were identified and quantitative PCR (qPCR) evidenced an increase in mRNA transcript levels of both ABC transporters during the two-cell, as well as an overall decrease during the blastulae stage. Calcein-AM efflux activity assay indicated the activation of multidrug resistance-associated protein/ABCC-like transport in the presence of HgCl2 and TBT in exposed blastulae. The in situ hybridisation of the two-cell and blastula stages showed ubiquitous localisation of both transcripts within cells, supporting qPCR data. In conclusion, ABCB1 and ABCC9 are constitutive, as are HgCl2, TBT and OXI-inducible ABC membrane transporters, coexpressed in the zygote, two-cell and blastula stages of the P. lividus. Their ubiquitous cell localisation further fortifies their protective role in early embryonic development. PMID:23690080

Bošnjak, Ivana; Plei?, Ivana Lepen; Borra, Marco; Mladineo, Ivona

2013-12-01

230

Aquatic toxicity testing for multicomponent compounds with special reference to preparation of test solution  

SciTech Connect

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.

Tadokoro, H.; Maeda, M.; Kawashima, Y.; Kitano, M.; Hwang, D.F.; Yoshida, T. (Chemical Biotesting Center, Chemicals Inspection and Testing Institute, Tokyo (Japan))

1991-02-01

231

Results of acute and chronic toxicity tests conducted at SRS NPDES outfalls, July--October 1991  

SciTech Connect

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.

Specht, W.L.

1992-01-01

232

INTRA- AND INTERLABORATORY VARIABILITY IN ACUTE TOXICITY TESTS WITH GLOCHIDIA AND JUVENILES OF FRESHWATER MUSSELS (UNIONIDAE)  

Microsoft Academic Search

Abstract—The present study evaluated,the performance,and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods,outlined in American,Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels,were,conducted,within a single laboratory and among,five laboratories. All tests met the test acceptability requirements (e.g., 90% control survival). Intralaboratory tests were

Ning Wang; Tom Augspurger; M. Chris Barnhart; Joseph R. Bidwell; W. Gregory Cope; F. James Dwyer; Steve Geis; I. Eugene Greer; Chris G. Ingersoll; Cynthia M. Kane; Thomas W. May; Richard J. Neves; Teresa J. Newton; Andy D. Roberts; David W. Whites

2007-01-01

233

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...

234

Comparison of prehatch C-start responses in rainbow trout and lake trout embryos by means of a tactile stimulus test  

USGS Publications Warehouse

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.

Wright, P.J.; Noltie, D.B.; Tillitt, D.E.

2003-01-01

235

Methods For Collecting , Culturing And Performing Toxicity Tests With Daphnia ambigua  

SciTech Connect

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 financial support associated with maintaining the cultures until testing is needed. The purpose of this document is to provide guidance on how to establish a laboratory culture of D. ambigua so that a culture can be restarted when needed.

Specht, Winona L.

2005-07-01

236

REVIEW OF THE CURRENT STATUS OF MARINE ALGAL TOXICITY TESTING IN THE UNITED STATES  

EPA Science Inventory

Algal toxicity testing is not new, but only within the past few years have data from such testing been used to help set standards for allowable contamination. arly toxicity testing with marine algae used a few planktonic species with inhibition of growth as the primary endpoint. ...

237

SEED GERMINATION AND ROOT ELONGATION TOXICITY TESTS IN HAZARDOUS WASTE SITE EVALUATION: METHODS DEVELOPMENT AND APPLICATIONS  

EPA Science Inventory

Seed germination tests measure soil toxicity directly, while root elongation tests consider the indirect effects of water-soluble constituents which may be present in site-samples. n the seed germination toxicity test, site-soil is mixed with a reference soil to yield exposure co...

238

MARINE COMPLEX EFFLUENT TOXICITY PROGRAM: TEST SENSITIVITY, REPEATAELITY AND RELEVANCE TO RECEIVING WATER TOXICITY  

EPA Science Inventory

In March 1984, the U.S. Environmental Protection Agency (EPA) issued a significant change in procedures regulating toxic materials in effluents through the National Pollutant Discharge Elimination System (NPDES). Concurrent with this toxicity-based effluent control policy, the EP...

239

65 FR 78746 - Toxic Substances Control Act Test Guidelines  

Federal Register 2010, 2011, 2012, 2013, 2014

...under appropriate conditions. (8) Clinical Biochemistry. (i) Clinical biochemistry determinations to investigate major toxic...determination of hematological and clinical biochemistry variables before dosing...

2000-12-15

240

Lethal and sublethal toxicity of the industrial chemical epichlorohydrin on Rhinella arenarum (Anura, Bufonidae) embryos and larvae.  

PubMed

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. PMID:24231313

Hutler Wolkowicz, Ianina R; Aronzon, Carolina M; Pérez Coll, Cristina S

2013-12-15

241

Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos  

USGS Publications Warehouse

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.

Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D.

1995-01-01

242

Computational Systems Biology and Dose-Response Modeling in Relation to New Directions in Toxicity Testing  

Microsoft Academic Search

The new paradigm envisioned for toxicity testing in the 21st century advocates shifting from the current animal-based testing process to a combination of in vitro cell-based studies, high-throughput techniques, and in silico modeling. A strategic component of the vision is the adoption of the systems biology approach to acquire, analyze, and interpret toxicity pathway data. As key toxicity pathways are

Qiang Zhang; Sudin Bhattacharya; Melvin E. Andersen; Rory B. Conolly

2010-01-01

243

Evaluation of three soil toxicity tests used to monitor acceptable endpoints  

SciTech Connect

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.

Brinkmann, M.; Stroo, H.; Leuschner, A.; Leuteritz, D.; Stromberg, M.; Brourman, M.

1995-12-31

244

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...

245

Aquatic toxicity tests for the control of effluent discharges in the UK - the influence of test precision.  

PubMed

: The initiative by the River Purification Boards (RPBs), National Rivers Authority (NRA) and Her Majesty's Inspectorate of Pollution (HMIP) to control certain complex and toxic effluent discharges by direct toxicity assessment places great emphasis on the use of aquatic toxicity tests. Like all biological and analytical measurements, determinations of toxicity exhibit variability. When setting 'Toxicity-based Consents' (TBCs) and monitoring for compliance with such consents, it is important to understand and if possible control this variability. The implications of toxicity test variability for the way TBCs may be set and monitored are discussed; including a consideration of monitoring consents based on a single exposure concentration (limit) test and procedures involving a range of exposure concentrations (concentration-response test). We also review the precision of data arising from acute aquatic toxicity test methods which may be used for the control and monitoring of complex effluents in the UK. This includes the variability that occurs when repeated tests are carried out on different occasions within the same laboratory (repeatability) and also within different laboratories (reproducibility). Particular attention is given to acute tests using Daphnia magna, the only method for which there is a large amount of published information on the precision of toxicity data. PMID:24193722

Whitehouse, P; Crane, M; John Redshaw, C; Turner, C

1996-06-01

246

A comparison of relative toxicity rankings by some small-scale laboratory tests  

NASA Technical Reports Server (NTRS)

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.

Hilado, C. J.; Cumming, H. J.

1977-01-01

247

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 ...

248

SUITABILITY OF SHEEPSHEAD MINNOWS ('CYPRINODON VARIEGATUS') FOR LIFE-CYCLE TOXICITY TESTS  

EPA Science Inventory

Entire life-cycle toxicity tests are practical with sheepshead minnows, Cyprinodon variegatus. This is the only estuarine fish that has been utilized successfully in life-cycle toxicity tests, using methods formulated only since 1973. Salinity, temperature, and spawning requireme...

249

PERIPHYTON PHOTOSYNTHESIS AS AN INDICATOR OF EFFLUENT TOXICITY: RELATIONSHIP TO EFFECTS ON ANIMAL TEST SPECIES  

EPA Science Inventory

The use of aquatic plants in effluent toxicity evaluations is uncommon despite the availability of test methods and numerous recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity ...

250

Population growth rate determinants for Arbacia: Evaluating ecological relevance of toxicity test endpoints  

SciTech Connect

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.

Nacci, D.; Gleason, T.; Munns, W.R. Jr. [Environmental Protection Agency, Narragansett, RI (United States). Environmental Research Lab.

1995-12-31

251

Development and application of a marine sediment porewater toxicity test using algal spores  

SciTech Connect

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.

Hooten, R. [Texas A and M Univ., Corpus Christi, TX (United States); Carr, R.S. [National Biological Service, Corpus Christi, TX (United States)

1995-12-31

252

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....

253

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...

254

Pyrrolizidine Alkaloids: Testing for Toxic Constituents of Comfrey.  

ERIC Educational Resources Information Center

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)

Vollmer, John J.; And Others

1987-01-01

255

In situ toxicity tests of fishes in acid waters  

Microsoft Academic Search

Toxicity of waters within the North Branch of the Moose River to various life stages of lake trout (Salvelinus namaycush), brook trout (Salvelinus fontinalis), creek chub (Semotilus atromaculatus), and blacknose dace (Rhinichthys atratulus) were examined in situ. Study sites were selected that were expected to range from toxic to favourable water quality. For example, pH varied from 4.25 to 7.17,

David W. Johnson; Howard A. Simonin; James R. Colquhoun; Frank M. Flack

1987-01-01

256

Evaluation of whole effluent toxicity data characteristics and use of Welch's T-test in the test of significant toxicity analysis.  

PubMed

The U.S. Environmental Protection Agency (U.S. EPA) and state agencies evaluate the toxicity of effluent and surface water samples based on statistical endpoints derived from multiconcentration tests (e.g., no observed effect concentration, EC25). The test of significant toxicity (TST) analysis is a two-sample comparison test that uses Welch's t test to compare organism responses in a sample (effluent or surface water) with responses in a control or site sample. In general, any form of t test (Welch's t included) is appropriate only if the data meet assumptions of normality and homogeneous variances. Otherwise, nonparametric tests are recommended. TST was designed to use Welch's t as the statistical test for all whole effluent toxicity (WET) test data. The authors evaluated the suitability of using Welch's t test for analyzing two-sample toxicity (WET) data, and within the TST approach, by examining the distribution and variances of data from over 2,000 WET tests and by conducting multiple simulations of WET test data. Simulated data were generated having variances and nonnormal distributions similar to observed WET test data for control and the effluent treatment groups. The authors demonstrate that (1) moderately unequal variances (similar to WET data) have little effect on coverage of the t test or Welch t test (for normally distributed data), and (2) for nonnormally distributed data (similar in distribution to WET data) TST, using Welch's t test, has close to nominal coverage on the basis of simulations with up to a ninefold difference in variance between the effluent and control groups (?95th percentile based on observed WET test data). PMID:23172744

Zheng, Lei; Diamond, Jerry M; Denton, Debra L

2013-02-01

257

TWO SHORT-TERM TOXICITY TESTS FOR THE CALANOID COPEPOD 'EURYTEMORA HERDMANI' USING A COMPLEX EFFLUENT  

EPA Science Inventory

Test designs and methodologies for two short-term static renewal tests, a 96-hr lethality test and a 5-day reproductive test, are described and statistically evaluated. The tests were developed specifically for use in the assessment of the toxicity of mixed effluents to copepods....

258

78 FR 66700 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data  

Federal Register 2010, 2011, 2012, 2013, 2014

...Acute Toxicity to Mammals; Bacterial Reverse Mutation Assay...and Water Solubility; in cellulose fabrics; Ready Biodegradability...for textiles; Potential (Bacterial bleaching agent 2-15 for...Toxicity; Acute Oral Toxicity; Bacterial Reverse Mutation (Ames...

2013-11-06

259

Influence of sediment composition on apparent toxicity in a solid-phase test using bioluminescent bacteria  

Microsoft Academic Search

Clean and spiked sediment formulations of various silt:sand and clay:sand ratios were tested for toxicity using a bioassay that utilizes bioluminescent bacteria. Measured toxicities of clean and copper sulfate-spiked sediments were negatively but nonlinearly related with percent silt and percent clay, but no significant relationship existed between measured toxicity and sediment composition for methyl parathion-spiked formulations. Results suggest that solid-phase

Michael J. Benton; Michelle L. Malott; Scott S. Knight; Charles M. Cooper; William H. Benson

1995-01-01

260

Microfluidic EmbryoSort technology: towards in flow analysis, sorting and dispensing of individual vertebrate embryos  

NASA Astrophysics Data System (ADS)

The demand to reduce the numbers of laboratory animals has facilitated the emergence of surrogate models such as tests performed on zebrafish (Danio rerio) or African clawed frog's (Xenopus levis) eggs, embryos and larvae. Those two model organisms are becoming increasingly popular replacements to current adult animal testing in toxicology, ecotoxicology and also in drug discovery. Zebrafish eggs and embryos are particularly attractive for toxicological analysis due their size (diameter 1.6 mm), optical transparency, large numbers generated per fish and very straightforward husbandry. The current bottleneck in using zebrafish embryos for screening purposes is, however, a tedious manual evaluation to confirm the fertilization status and subsequent dispensing of single developing embryos to multitier plates to perform toxicity analysis. Manual procedures associated with sorting hundreds of embryos are very monotonous and as such prone to significant analytical errors due to operator's fatigue. In this work, we present a proofof- concept design of a continuous flow embryo sorter capable of analyzing, sorting and dispensing objects ranging in size from 1.5 - 2.5 mm. The prototypes were fabricated in polymethyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining. The application of additive manufacturing processes to prototype Lab-on-a-Chip sorters using both fused deposition manufacturing (FDM) and stereolithography (SLA) were also explored. The operation of the device was based on a revolving receptacle capable of receiving, holding and positioning single fish embryos for both interrogation and subsequent sorting. The actuation of the revolving receptacle was performed using a DC motor and/or microservo motor. The system was designed to separate between fertilized (LIVE) and non-fertilized (DEAD) eggs, based on optical transparency using infrared (IR) emitters and receivers.

Fuad, Nurul M.; Wlodkowic, Donald

2013-12-01

261

Sediment toxicity testing with the amphipod Ampelisca abdita in Calcasieu Estuary, Louisiana  

USGS Publications Warehouse

Discharges from chemical and petrochemical manufacturing facilities have contaminated portions of Louisiana's Calcasieu River estuary with a variety of organic and inorganic contaminants. As part of a special study, sediment toxicity testing was conducted to assess potential impact to the benthic community. Ten-day flow-through sediment toxicity tests with the amphipod Ampelisca abdita revealed significant toxicity at 68% (26 of 38) of the stations tested. A. abdita mortality was highest in the effluent-dominated bayous, which are tributaries to the Calcasieu River. Mortality was correlated with total heavy metal and total organic compound concentrations in the sediments. Ancillary experiments showed that sediment interstitial water salinity as low as 2.5 o/o-o did not significantly affect A. abdita's, response in the flow-through system; sediment storage for 7 weeks at 4??C did not significantly affect toxicity. Sediment toxicity to A. abdita was more prevalent than receiving water toxicity using three short-term chronic bioassays. Results suggest that toxicity testing using this amphipod is a valuable tool when assessing sediments containing complex contaminant mixtures and for assessing effects of pollutant loading over time. In conjunction with chemical analyses, the testing indicated that the effluent-dominated, brackish bayous (Bayou d'Inde and Bayou Verdine) were the portions of the estuary most impacted by toxicity.

Redmond, M.S.; Crocker, P.A.; McKenna, K.M.; Petrocelli, E.A.; Scott, K.J.; Demas, C.R.

1996-01-01

262

Tests with Daphnia magna: a new approach to prescreen toxicity of newly synthesized acetylcholinesterase reactivators.  

PubMed

Reactivators of phosphorylated acetylcholinesterase (oximes) are substances used as a human antidotal therapy for organophosphate poisoning. The objective of our study was to examine if juveniles of freshwater microcrustacean Daphnia magna could be employed as test animals in early screen toxicity tests of those substances as a first step for further experiments with daphnids intoxicated by organophosphates. For this purpose, seven different oximes were investigated. It was found that toxicity of all tested oximes increased with time. Mono-quaternary oximes were approximately ten fold (EC50, 14.9 mg.l(-1)) more toxic in 24 hour tests and five fold (EC50 was 79.46 mg.l(-1)) more toxic in 48 hour tests than bis-quaternary oximes. Tests with daphnids were shown to be easy to carry out at low cost and provided valuable results which could be used as a starting point for further research. PMID:17059176

Vesela, Sarka; Ondruska, Vlastimil; Kuca, Kamil; Patocka, Jiri

2006-08-01

263

Original article Combining use of embryo sexing  

E-print Network

Original article Combining use of embryo sexing and cloning within mixed MOETs for selection) Summary - Given the same overall number of transferred embryos, a comparison was carried out between adult mixed (ie with bull progeny-testing) MOET (multiple ovulation and embryo-transfer) schemes with embryo

Paris-Sud XI, Université de

264

Validation of plant based bioassays for the toxicity testing of Indian waters  

Microsoft Academic Search

Plant-based bioassays have recently gained remarkable popularity among the toxicological\\/eco-toxicological assessment procedures.\\u000a The reasons for their wide use are comparative simplicity, sensitivity, and cost-effectiveness as well as a good correlation\\u000a with other toxicity tests. The present study describes the use of two plant bioassays, Allium cepa test and seed germination test in the evaluation of the toxicity\\/genotoxicity of industrial waste

Athar Habib Siddiqui; Shams Tabrez; Masood Ahmad

2011-01-01

265

Toxicity of polybrominated diphenyl ethers (DE-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings.  

PubMed

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01-20 microg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3',4,4',5-pentachlorobiphenyl; 0.002 microg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 microg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 microg/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 microg total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife. PMID:19045936

McKernan, Moira A; Rattner, Barnett A; Hale, Robert C; Ottinger, Mary Ann

2009-05-01

266

Cytogenetic Alterations in Preimplantation Mice Embryos Following Male Mouse Gonadal Gamma-irradiation: Comparison of Two Methods for Reproductive Toxicity Screening  

PubMed Central

Background Genome instability is a main cause of chromosomal alterations in both somatic and germ cells when exposed to environmental, physical and chemical genotoxicants. Germ cells especially spermatozoa are more vulnerable to suffering from DNA damaging agents during spermatogenesis and also more potent in transmitting genome instability to next generation. Methods To investigate the effects of ?-rays on inducing abnormalities manifested as numerical Chromosome Aberrations (CA) and Micronucleus (MN) in preimplantation embryos, adult male NMRI mice were irradiated with 4 Gy of ?-rays. They were then mated at weekly intervals with superovulated, non-irradiated female mice in 6 successive weeks. About 68 hr post coitous, four to eight cell embryos were retrieved and fixed on slides using standard methods in order to screen for CA and MN. Results In embryos generated from irradiated mice, the frequency of aneuploidy and MN increased dramatically at all post-irradiation sampling times as compared to the control (p<0.01). The frequency of embryos expressed MN was much higher than chromosomally abnormal embryos, although the trend of MN formation was similar to chromosomal abnormalities seen in corresponding sampling times. Conclusion Irradiation of sperms at any stages of spermatogenesis may lead to stable chromosomal abnormalities affecting pairing and disjunction of chromosomes in successive preimplantation embryos that are expressed as MN. Although chromosome analysis of embryos showed various types of chromosomal abnormalities, MN assay provide a simpler and faster technique for investigating the genotoxicity of agents affecting embryos at preimplantation stages. PMID:25215176

Salimi, Mahdieh; Mozdarani, Hossein; Nazari, Elmina

2014-01-01

267

Evaluation of an alternative in vitro test battery for detecting reproductive toxicants in a grouping context.  

PubMed

Previously we showed a battery consisting of CALUX transcriptional activation assays, the ReProGlo assay, and the embryonic stem cell test, and zebrafish embryotoxicity assay as 'apical' tests to correctly predict developmental toxicity for 11 out of 12 compounds, and to explain the one false negative (Piersma et al., 2013 [7]). Here we report on applying this battery within the context of grouping and read across, put forward as a potential tool to fill data gaps and avoid animal testing, to distinguish in vivo non- or weak developmental toxicants from potent developmental toxicants within groups of structural analogs. The battery correctly distinguished 2-methylhexanoic acid, monomethyl phthalate, and monobutyltin trichloride as non- or weak developmental toxicants from structurally related developmental toxicants valproic acid, mono-ethylhexyl phthalate, and tributyltin chloride, respectively, and, therefore, holds promise as a biological verification model in grouping and read across approaches. The relevance of toxicokinetic information is indicated. PMID:25461900

Kroese, E Dinant; Bosgra, Sieto; Buist, Harrie E; Lewin, Geertje; van der Linden, Sander C; Man, Hai-Yen; Piersma, Aldert H; Rorije, Emiel; Schulpen, Sjors H W; Schwarz, Michael; Uibel, Frederik; Vugt-Lussenburg, Barbara M A van; Wolterbeek, Andre P M; van der Burg, Bart

2014-10-14

268

Computerized In Vitro Test for Chemical Toxicity Based on Tetrahymena Swimming Patterns  

NASA Technical Reports Server (NTRS)

An apparatus and a method for rapidly determining chemical toxicity have been evaluated as an alternative to the rabbit eye initancy test (Draize). The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The method, called the motility assay (MA), is tested for 30 s to determine the chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy.

Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

1994-01-01

269

DEVELOPMENT OF A TOXICITY TEST SYSTEM USING PRIMARY RAT LIVER CELLS  

EPA Science Inventory

A model in vitro rat liver parenchymal cellular toxicity system employing cells obtained by the in situ collagenase perfusion technique has been developed to detect potential liver toxicants. The initial evaluation of this test system was accomplished using cadmium chloride, chro...

270

Development and application of whole-sediment toxicity test using immobilized freshwater microalgae Pseudokirchneriella subcapitata.  

PubMed

A method for a whole-sediment toxicity test using alginate immobilized microalgae Pseudokirchneriella subcapitata was developed using spiked sediments and applied to contaminated field sediment samples. For method development, a growth inhibition test (72 h) with algal beads was conducted for the sediments spiked with Cu or diuron. The method was validated by determining dose-response relationships for Cu and diuron in both fine-grained and coarse-grained sediments. The results of a spiked sediment toxicity test suggested that sediment particle size distribution (clay content) had a significant effect on the growth of P. subcapitata. The developed method using immobilized microalgae P. subcapitata beads was applied successfully in the toxicity test and toxicity identification evaluation (TIE) for the four field sediment samples. After a series of extractions with 0.01 M CaCl(2) solution, acetone, and dichloromethane, the extracted sediment, which was shown to be nontoxic to algae, was used as the control and diluent for the same sediment in the whole-sediment toxicity test. The results showed that all investigated field sediment samples were found to be toxic to the immobilized algae P. subcapitata, with their median effective concentration (EC50) values ranging from 41.4 to 79.0% after 72 h exposure. In the whole sediment TIE, growth of P. subcapitata was improved to varying degrees after adding zeolite, resin, or activated charcoal, suggesting different contributions to toxicity from ammonia, metals, and organic contaminants in the tested sediments. PMID:22065399

Zhang, Li-Juan; Ying, Guang-Guo; Chen, Feng; Zhao, Jian-Liang; Wang, Li; Fang, Yi-Xiang

2012-02-01

271

ExpoCast: Exposure Science for Prioritization and Toxicity Testing  

EPA Science Inventory

The US EPA is completing the Phase I pilot for a chemical prioritization research program, called ToxCastTM. Here EPA is developing methods for using computational chemistry, high-throughput screening, and toxicogenomic technologies to predict potential toxicity and prioritize l...

272

Testing, Toxicity and Exposure: How Safe is "No Unreasonable  

E-print Network

#12;2 2 Outline Pesticide Regulations Risk Assessments ­ Hazard Assessments ­ Exposure Assessments FQPA 1996 Required EPA to: re-assess all pesticides/uses consider exposure from all non ASSESSMENT MANAGEMENT EXPOSURE Risk Assessment ­ 4 elements Toxicity of the pesticide ­ potential hazards

Watson, Craig A.

273

Toxicity tests of soil contaminated by recycling of scrap plastics  

Microsoft Academic Search

The present investigation studied the toxicity of soil contaminated by untreated discharge from a factory that recycles used plastics. The nearby agricultural areas and freshwater fish ponds were polluted with high concentrations of Cu, Ni, and Mn. Water extracts from the contaminated soil retarded root growth of Brassica chinensis (Chinese white cabbage) and Cynodon dactylon (Bermuda grass) where their seeds

M. H. Wong; V. W. Chui

1990-01-01

274

Development of a test system for screening toxic substances: a comparison using organic substances  

SciTech Connect

The purpose of this research was to develop a test system for screening toxic substances by predicting their aquatic ecosystem effects. The system studied was a static, one liter microcosm with a diverse species assemblage. The microcosm was composed of biotic inoculum, chemically defined medium and sediment. The biotic inoculum contained primary producers, grazers, carnivores and decomposers. Three different types of sediment were studied: sand, clay, and clay plus sand. Four organic chemicals: phenol, triethylene glycol (TEG), quinoline and naphthoquinone were evaluated with this test system. The toxicities of TEG, quinoline and naphthoquinone were compared for each sediment type. Toxicity was evaluated in terms of the chemical's effects on primary productivity and heterotrophic activity though other effects are also noted. Naphthoquinone concentration exhibited no correlation between ecosystem property values and therefore, could not be ranked. Phenol exhibited the greatest toxicity to net production immediately after the toxicant addition. Quinoline was most toxic to net production over the longer time scale. TEG exhibited the least toxicity to net production, however, TEG exhibited higher toxicity to heterotrophic activity than either quinoline or phenol. Although the type of sediment used in the microcosms did not change the relative toxicities of the chemicals, the microcosms with clay sediment always were observed to exhibit lower net production and higher variability.

Thomas, C.L.

1985-01-01

275

Assessment of four different test designs for Hyalella azteca 10 days sediment toxicity test  

SciTech Connect

The purpose of this study was to assess the adequacy of four experimental designs of the Hyalella azteca 10 days sediment toxicity test. The authors conducted a series of sediment toxicity tests using an EPA recommended experimental design (8 chambers with 10 organisms per treatment) and three other designs. These had the same total number of organisms (80) per treatment and the same sediment:water ratio (1:1.5) but different number of chambers (4,2,1). The number of organisms recovered, the time to sort and count the animals, as well as the time to make a water change were compared for these four designs. Logistic regression was used to analyze the recovery data while one-way analysis of variance methods were used to analyze the time responses. The results showed that the four treatments were comparable in terms of proportion of organisms recovered. However, the sorting time and the water change time decreased as the number of chambers decreased, making those designs with less chambers more desirable.

Ramirez-Romero, P. [Autonomous Metropolitan Univ., Mexico City (Mexico). Hydrobiology Dept.; [Miami Univ., Oxford, OH (United States). Zoology Dept.; Oris, J.T.; Bailer, J.; DePoy, M. [Miami Univ., Oxford, OH (United States)

1995-12-31

276

Environmental impact assessment of tailings dispersal from a uranium mine using toxicity testing protocols  

SciTech Connect

Toxicity testing is a means of establishing the environmental risk of uranium tailings release. It is valuable in designing tailings containment structures because it assists in setting acceptable levels of risk of the design. This paper presents details of toxicity tests of the tailings from Ranger Uranium Mine, Northern Territory, Australia. The results suggest that the non-radiological toxicity of the tailings is low. The environmental risk of a tailings release is more likely to be related to the physical impacts of the tailings, including infilling of billabongs and changes in the sedimentology of riparian ecosystems rather than their biogeochemical impact. Two major results were: (1) water from treatment with washed tailing fines was not toxic to Hydra viridissima, and (2) mixtures of washed tailings fines and natural floodplain sediment (overlying water or elutriates) were not toxic to Hydra viridissima or Moinodaphnia macleayi. 33 refs., 4 figs., 3 tabs.

Rippon, G.D. [Environmental Protection Agency, Canberra (Australia); Riley, S.J. [Univ. of Western Sydney-Nepean, Kingswood (Australia)

1996-12-01

277

Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores  

USGS Publications Warehouse

An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH3) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH3 than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH3 concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH3 concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH3 and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH3.

Hooten, R.L.; Carr, R.S.

1998-01-01

278

Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores  

SciTech Connect

An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH{sub 3}) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH{sub 3} than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH{sub 3} concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH{sub 3} concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH{sub 3} and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH{sub 3}.

Hooten, R.L.; Carr, R.S. [Texas A and M Univ., Corpus Christi, TX (United States). Geological Survey

1998-01-01

279

EVALUATION OF A SHORT-TERM CHRONIC EFFLUENT TOXICITY TEST USING SHEEPSHEAD MINNOW (CYPRINODON VARIEGATUS) LARVAE  

EPA Science Inventory

In response to recent changes in National Pollutant Discharge Elimination System (NPDES) permit regulations, rapid (7-day) static renewal toxicity tests have been developed to detect chronic (sublethal and lethal) effect concentrations of municipal and industrial effluents on fre...

280

EPAS TOXCAST PROGRAM FOR PREDICTING HAZARD AND PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS(S).  

EPA Science Inventory

EPAs National Center for Computational Toxicology is developing methods that apply computational chemistry, high-throughput screening (HTS) and genomic technologies to predict potential toxicity and prioritize the use of limited testing resources....

281

EPA'S TOXCAST PROGRAM FOR PREDICTING HAZARD AND PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

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 that likely represent the greatest hazard to human ...

282

EPA's Toxcast ? Program for Predicting Hazard and Priortizing Toxicity Testing of Environemntal Chemicals (T)  

EPA Science Inventory

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 that likely represent the greatest hazard to human ...

283

MOTOR ACTIVITY: A SURVEY OF METHODS WITH POTENTIAL USE IN TOXICITY TESTING  

EPA Science Inventory

Activity measurements are expected to have widespread use in toxicity testing. The multifaceted nature of motor activity will directly influence the selection of a measurement technique since the relative contribution of various motor acts to any particular measurement will depen...

284

A Roadmap for the Development of Alternative (Non-Animal) Methods for Systemic Toxicity Testing  

EPA Science Inventory

Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new prod...

285

Intra- and interlaboratory variability in acute toxicity tests with glochidia and juveniles of freshwater mussels (Unionidae).  

PubMed

The present study evaluated the performance and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods outlined in American Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels were conducted within a single laboratory and among five laboratories. All tests met the test acceptability requirements (e.g., >or=90% control survival). Intralaboratory tests were conducted over two consecutive mussel-spawning seasons with mucket (Actinonaias ligamentina) or fatmucket (Lampsilis siliquoidea) using copper, ammonia, or chlorine as a toxicant. For the glochidia of both species, the variability of intralaboratory median effective concentrations (EC50s) for the three toxicants, expressed as the coefficient of variation (CV), ranged from 14 to 27% in 24-h exposures and from 13 to 36% in 48-h exposures. The intralaboratory CV of copper EC50s for juvenile fatmucket was 24% in 48-h exposures and 13% in 96-h exposures. Interlaboratory tests were conducted with fatmucket glochidia and juveniles by five laboratories using copper as a toxicant. The interlaboratory CV of copper EC50s for glochidia was 13% in 24-h exposures and 24% in 48-h exposures, and the interlaboratory CV for juveniles was 22% in 48-h exposures and 42% in 96-h exposures. The high completion success and the overall low variability in test results indicate that the test methods have acceptable precision and can be performed routinely. PMID:17867871

Wang, Ning; Augspurger, Tom; Barnhart, M Chris; Bidwell, Joseph R; Cope, W Gregory; Dwyer, F James; Geis, Steve; Greer, I Eugene; Ingersoll, Chris G; Kane, Cynthia M; May, Thomas W; Neves, Richard J; Newton, Teresa J; Roberts, Andy D; Whites, David W

2007-10-01

286

Scientific rationale for the selection of toxicity testing methods. II. Teratology, immunotoxicology, and inhalation toxicology  

SciTech Connect

This document is the second of a two-part literature analysis of parameters associated with the various toxicity testing methods (test anial selection, pathology, etc.). Acute, subchronic, chronic, and carcinogenic testing methods are covered in ORNL/EIS-151. Testing methods for developmental toxicity, immunotoxicology, and inhalation toxicology and research needs associated with these areas are covered in this volume, ORNL-6094. These reports were prepared for the purpose of assisting and supporting the US Environmental Protection Agency in its efforts to develop guidelines for more efficient and economical testing procedures. 416 refs., 29 figs., 27 tabs.

Ryon, M.G.; Sawhney, D.S. (eds.)

1985-09-01

287

Genotoxicity and toxicity evaluations of ECF cellulose bleaching effluents using the Allium cepa L. test.  

PubMed

Toxicity and genotoxicity tests were performed on root cells of Allium cepa in order to evaluate wastewater quality following an ECF cellulose bleaching process. The results revealed a toxic effect of the effluent, with inhibition of meristem growth and generally lower values of metaphase, anaphase and telophase indices at pH 10.5 than pH 7 for all effluent concentrations. The genotoxicity effect was different from the toxic effect given that the micronucleus and the chromosomal aberration tests in anaphase-telophase cells were low over all ranges of the studied effluent concentrations. PMID:22990817

Roa, O; Yeber, M C; Venegas, W

2012-08-01

288

Use of sublethal endpoints in sediment toxicity testing with the amphipod Hyalella azteca  

SciTech Connect

ASTM and EPA standard methods for sediment toxicity tests with Hyalella azteca typically recommend use of lethality as the endpoint in a 10-d exposure. However, data from 10- to 28-d exposures with amphipods indicate sublethal endpoints (i.e., growth, sexual maturation, or reproduction) identify additional samples as toxic. The authors compared the frequency that lethal and sublethal endpoints identified a sediment sample as toxic in 14- and 28-d amphipod exposures. In the 14-d amphipod exposures, lethality identified 20% of the samples as toxic, and sublethal endpoints identified an additional 16% of the samples as toxic using sublethal endpoints only. Similarly, in the 28-d exposures, lethality identified 14% of the samples as toxic and sublethal endpoints identified an additional 18% of the samples as toxic. The authors are also currently evaluating Sediment Effect Concentrations (SECs) relative to both lethal and sublethal endpoints in H. azteca exposures. These SECs will be used to evaluate reliability in estimating toxicity of samples. Potential factors which may confound interpretation of sublethal endpoints in sediment tests include: (1) changes in sediment chemistry resulting from long-term storage or feeding (2) the influence of physical characteristics of sediment (grain size), and (3) effects of ammonia or hydrogen sulfide.

Kemble, N.E.; Brunson, E.B.; Dwyer, F.J.; Ehrhardt, E.A.; Hardesty, D.K.; Haverland, P.S.; Ingersoll, C.G. [National Biological Service, Columbia, MO (United States). Midwest Science Center

1995-12-31

289

Toxicity tests of effluents with marsh plants in water and sediment  

SciTech Connect

Methods are described for toxicity testing of water and sediment with two varieties of the freshwater marsh plant Echinochloa crusgalli (Linneaus) Palisot de Beauvois (Poaceae), and complex effluents. Two tests are described: a seed germination and early seedling growth test in water, and a survival and seedling growth test in natural and synthetic sediments. Effects of effluents from a sewage treatment plant, tannery, textile mill, pulp and paper mill, coking plant and sewage treatment plant included inhibition of germination, chlorophyll synthesis and growth. The tests with rooted marsh plants were sensitive to pollutants and detected toxicity of a range of pollutants in water and sediment. Synthetic sediments similar to natural sediments allowed toxicity tests to be done under carefully controlled conditions of particle size distribution, organic content, pH, electrode potential (Eh) and cation exchange capacity (CEC).

Walsh, G.E.; Weber, D.E.; Simon, T.L.; Brashers, L.K.

1991-01-01

290

Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests  

Microsoft Academic Search

Sediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P [>=] 0.05) but did reduce growth in all three test species

T. B. Reynoldson; K. E. Day; C. Clarke; D. Milani

1994-01-01

291

Influence of sediment composition on apparent toxicity in a solid-phase test using bioluminescent bacteria  

SciTech Connect

Clean and spiked sediment formulations of various silt:sand and clay:sand ratios were tested for toxicity using a bioassay that utilizes bioluminescent bacteria. Measured toxicities of clean and copper sulfate-spiked sediments were negatively but nonlinearly related with percent silt and percent clay, but no significant relationship existed between measured toxicity and sediment composition for methyl parathion-spiked formulations. Results suggest that solid-phase sediment bioassays using bioluminescence bacteria may be useful for testing the toxicities of single contaminants in formulated artificial sediments of known particle-size composition, and for repeated samples collected from the same site. However, extreme caution must be taken when testing sediments of varying composition or which may be differentially contaminated or contain a suite of contaminants.

Benton, M.J. [East Tennessee State Univ., Johnson City, TN (United States). Dept. of Environmental Health; Malott, M.L. [Univ. of Mississippi, University, MS (United States)]|[Dept. of Agriculture, Oxford, MS (United States); Knight, S.S.; Cooper, C.M. [Dept. of Agriculture, Oxford, MS (United States); Benson, W.H. [Univ. of Mississippi, University, MS (United States)

1995-03-01

292

Cross-Sector Review of Drivers and Available 3Rs Approaches for Acute Systemic Toxicity Testing  

PubMed Central

Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or refining the use of animals, and (3) recommendations for future work in this area. PMID:20484382

Seidle, Troy; Robinson, Sally; Holmes, Tom; Creton, Stuart; Prieto, Pilar; Scheel, Julia; Chlebus, Magda

2010-01-01

293

Acute toxicity testing with the tropical marine copepod Acartia sinjiensis: optimisation and application.  

PubMed

Globally there is limited toxicity data for tropical marine species, and there has been a call for further research and development in the area of tropical marine ecotoxicology. An increase in developmental pressures in northern tropical Australia is causing a higher demand for toxicity test protocols with ecologically relevant species. Copepods are a diverse group of zooplankton that are major components of marine food webs. The calanoid copepod Acartia sinjiensis is widely distributed across tropical and sub-tropical brackish to marine waters of Australia and was identified in a recent comprehensive review of marine tropical toxicity testing in Australia as a suitable test organism. Through a number of optimisation steps including feeding trials, changes to culture and test conditions; a 48-h acute toxicity test with A. sinjiensis was modified to become a highly reliable and reproducible standard test protocol. Control mobility was improved significantly, and the sensitivity of A. sinjiensis to copper (EC50 of 33µg/L), ammonia (EC50 of 10mg/L) and phenol (EC50 of 13mg/L) fell within the ranges of those reported previously, indicating that the modifications did not alter its sensitivity. In a comprehensive literature search we found that this species was the most sensitive to copper out of a range of marine copepods. The test was also successfully applied in toxicity assessments of four environmental samples: two produced formations waters (PFWs) and two mine tailing liquors (MTLs). The toxicity assessments utilised toxicity data from a suite of marine organisms (bacteria, microalgae, copepods, sea urchins, oysters, prawns, and fish). For the PFWs, which were predominantly contaminated with organic chemicals, A. sinjiensis was the most sensitive species (EC50 value 2-17 times lower than for any other test species). For the predominantly metal-contaminated mine tailing liquors, its sensitivity was similar to that of other test species used. The modified 48-h acute toxicity test with A. sinjiensis proved to be a valuable tool in these toxicity assessments, and is recommended for use in tropical marine toxicity assessments for northern Australia. PMID:23932510

Gissi, F; Binet, M T; Adams, M S

2013-11-01

294

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2011 CFR

...and conditions using freshwater and marine algae to develop data on the phytotoxicity... means having the property of killing algae. (2) Algistatic means having the...solution. Start the test by introducing algae into the test and control...

2011-07-01

295

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2014 CFR

...and conditions using freshwater and marine algae to develop data on the phytotoxicity... means having the property of killing algae. (2) Algistatic means having the...solution. Start the test by introducing algae into the test and control...

2014-07-01

296

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2012 CFR

...and conditions using freshwater and marine algae to develop data on the phytotoxicity... means having the property of killing algae. (2) Algistatic means having the...solution. Start the test by introducing algae into the test and control...

2012-07-01

297

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2013 CFR

...and conditions using freshwater and marine algae to develop data on the phytotoxicity... means having the property of killing algae. (2) Algistatic means having the...solution. Start the test by introducing algae into the test and control...

2013-07-01

298

Revolutionizing Toxicity Testing For Predicting Developmental Outcomes (DNT4)  

EPA Science Inventory

Characterizing risk from environmental chemical exposure currently requires extensive animal testing; however, alternative approaches are being researched to increase throughput of chemicals screened, decrease reliance on animal testing, and improve accuracy in predicting adverse...

299

DEVELOPMENT OF A FATE/TOXICITY SCREENING TEST  

EPA Science Inventory

A shake-flask screening test was designed to rapidly evaluate the relative degradation rates of a wide spectrum of chemicals, each compared to methyl parathion. Test chemicals evaluated were bolero, bravo, dibutylphthalate, dimilin, dursban, endosulfan, hoelon, pentachlorobenzene...

300

EPA?s ToxCast Program for Predicting Toxicity and Prioritizing Chemicals for Further Screening and Testing  

EPA Science Inventory

Testing of environmental and industrial chemicals for toxicity potential is a daunting task because of the wide range of possible toxicity mechanisms. Although animal testing is one means of achieving broad toxicity coverage, evaluation of large numbers of chemicals is challengin...

301

Interpreting in vitro developmental toxicity test battery results: The consideration of toxicokinetics.  

PubMed

In the EU collaborative project ChemScreen an alternative, in vitro assay-based test strategy was developed to screen compounds for reproductive toxicity. A toxicokinetic modeling approach was used to allow quantitative comparison between effective concentrations in the in vitro test battery and observations of developmental toxicity in vivo. This modeling strategy is based on (1) the definition of relevant observations of toxicity in vivo, (2) simulation of the corresponding systemic concentrations in vivo by toxicokinetic modeling, and (3) correction for differences in protein binding and lipid partitioning between plasma and in vitro test media. The test results of a feasibility study with a number of known reproductive toxicants has been described previously (Piersma et al. [15]). In the present paper, we take a more detailed look at the toxicokinetics of these compounds, and add the analysis of some compounds from subsequent studies. We discuss how the consideration of toxicokinetics allowed comparison between test systems with differing test medium composition, has helped to interpret the in vitro findings in light of in vivo observations, and to gain confidence in the predictive value of the test battery outcomes. The same toxicokinetic modeling strategy, in reverse order, can now be used for risk assessment purposes to predict toxic doses in vivo from effective concentrations in vitro. PMID:25462785

Bosgra, Sieto; Westerhout, Joost

2014-11-11

302

Establishment of quality assurance procedures for aquatic toxicity testing with the nematode Caenorhabditis elegans  

SciTech Connect

In this study initial data were generated to develop laboratory control charts for aquatic toxicity testing using the nematode Caenorhabditis elegans. Tests were performed using two reference toxicants: CdCl{sub 2} and CuCl{sub 2}. All tests were performed for 24 h without a food source and of 48 h with a food source in a commonly used nematode aquatic medium. Each test was replicated 6 times with each replicate having 6 wells per concentration with 10 {+-} 1 worms per well. Probit analysis was used to estimate LC{sub 50} values for each test. The data were used to construct a mean ({bar x}) laboratory control chart for each reference toxicant. The coefficient of variation (CV) for three of the four reference toxicant tests was less than 20%, which demonstrates an excellent degree of reproducibility. These CV values are well within suggested standards for determination of organism sensitivity and overall test system credibility. A standardized procedure for performing 24 h and 48 h aquatic toxicity studies with C. elegans is proposed.

Freeman, M.N.; Marse, T.J.; Williams, P.L. [Univ. of Georgia, Athens, GA (United States). Environmental Health Science Program

1998-12-31

303

Results of Toxicity Tests on SRS NPDES Outfalls A-01, A-11, and G-10, January - September 2002  

SciTech Connect

The results of the 10 rounds of toxicity tests that were performed on SRS NPDES outfalls A-01, A-11 and G-10 indicate that there would have been no toxicity failures if these tests had been compliance tests. Except for one set of test results for G-10, all of the tests resulted in NOECs of 100 percent effluent. All of the tests met the criteria of less than a 25 percent mean reduction in reproduction for any quarter and less than a 40 percent reduction in any single test. Therefore, there is no reasonable potential to discharge toxic effluents in toxic amounts.

Specht, W.L.

2002-11-01

304

Comparative Toxicity of Eight Oil Dispersants, Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Aquatic Test Species  

EPA Science Inventory

This study describes the acute toxicity of eight commercial oil dispersants, Louisiana sweet crude oil (LSC), and chemically dispersed LSC. The approach utilized consistent test methodologies within a single laboratory in assessing the relative acute toxicity of the eight dispers...

305

Movement disorder and neuromuscular change in zebrafish embryos after exposure to caffeine  

Microsoft Academic Search

Though caffeine is broadly distributed in many plants and foods, little is known about the teratogenic effects of caffeine during early embryonic development. Here, we used zebrafish as a model to test toxicity and teratogenicity since they have transparent eggs, making the organogenesis of zebrafish embryos easier to observe. When the exposure doses of caffeine were less than 150 ppm (17.5,

Yau-Hung Chen; Yi-Hui Huang; Chi-Chung Wen; Yun-Hsin Wang; Wei-Li Chen; Li-Chao Chen; Huey-Jen Tsay

2008-01-01

306

EFFECTS OF BEAUVERIA BASSIANA TO EMBRYOS OF THE INLAND SILVERSIDE (MENIDIA BERYLLINA)  

EPA Science Inventory

A chemical toxicity/teratogenicity test was adapted to assess potential adverse affect of a microbial pest control agent on a nontarget fish. eveloping embryos of inland silverside, Menidia beryllina, were exposed to conidiospores or the insect-pathogenic fungus, Beauveria bassia...

307

DIETARY TOXICITY TEST FOR 2% DRC1339TREATED BROWN RICE ON NONTARGET AVIAN SPECIES  

Microsoft Academic Search

In Louisiana and Texas DRC-1339-treated brown rice is used to manage blackbird populations that cause severe damage to newly planted rice. Nontarget bird species have been observed on some DRC-1339 bait sites. We conducted dietary toxicity tests to provide additional data on the toxicity of DRC-1339 to the following nontarget species observed on DRC-1339 bait sites: savannah sparrows (Passerculus sandwichensis),

JOHN L. CUMMINGS; DARRYL L. YORK; KIRK J. SHIVELY; PATRICIA A. PIPAS; RANDAL S. STAHL; JAMES E. DAVIS

308

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2010 CFR

...around the trunk of the animal. The ends of the...subjects. In the testing of unctuous...one-half of the animals are further prepared...c) Procedures for testing. The sleeve is slipped onto the animal which is then...

2010-01-01

309

Rapid toxicity screening tests for aquatic biota. 1. Methodology and experiments with Daphnia magna  

SciTech Connect

A promising new and rapid toxicity screening test was developed, the concept and principles of which are presented. The method consists of visual observation of in vivo inhibition of an enzymatic process, using a fluorescent substrate. Juvenile Daphnia magna was exposed to a toxicant dilution series for 1 h, after which the substrate was added and the enzymatic inhibition was observed visually, using a long-wave UV light. The 1-h EC50 results of 11 pure compounds are presented and compared to the conventional 24- and 48-h Daphnia magna EC50s. All 1-h fluorescence EC50s were of the same order of magnitude and correlated very well with the 24- and 48-h EC50s. The sensitivity and reproducibility of this cost-effective screening test were compared to those of the Microtox[reg sign] test. The scope for application and the potential of this new rapid toxicity screening test are evaluated.

Janssen, C.R.; Persoone, G. (State Univ. of Ghent (Belgium))

1993-04-01

310

Dispersed oil toxicity tests with biological species indigenous to the Gulf of Mexico. Final report  

SciTech Connect

Static and flowthrough aquatic acute toxicity testing protocols were utilized on eggs and larvae of seven commercially important invertebrates and fishes from the Gulf of Mexico. Test organisms were exposed to Central and Western Gulf oils, dispersed oil, and Corexit 9527. Species included brown shrimp (Penaeus aztecus), white shrimp (Penaeus setiferus), blue crab (Callinectes sapidus), eastern oyster (Crassostrea virginica), red drum (Sciaenops ocellatus), inland silverside (Menidia berylina), and spot (Leiosomus xanthurus). Atlantic menhaden (Brevoortia tyrannus) was also tested because gulf menhaden were not available. Mysids (Mysidopsis bahia) were evaluated as part of a chronic toxicity assessment.

Fucik, K.W.; Carr, K.A.; Balcom, B.J.

1994-08-01

311

EVALUATION OF THE FATHEAD MINNOW SEVEN-DAY SUBCHRONIC TEST FOR ESTIMATING CHRONIC TOXICITY  

EPA Science Inventory

Renewal and flow-through subchronic tests were conducted on fathead minnows (Pimephales promelas) with nine chemicals and the results compared to early life stage (ELS) or life cycle toxicity values for one water type. In addition, ELS tests were conducted simultaneously with fou...

312

Applications of Toxicity Testing as a Tool: Things we've Learned  

EPA Science Inventory

Whole effluent toxicity (WET) testing methodologies have been widely used to assess potential adverse effects of wastewater discharges on aquatic life in the United States since the 1970?s. The tests have been incorporated into the U.S. Environmental Protection Agency?s Water Qu...

313

Perspectives on Validation of High-Throughput Assays Supporting 21st Century Toxicity Testing  

EPA Science Inventory

In vitro high-throughput screening (HTS) assays are seeing increasing use in toxicity testing. HTS assays can simultaneously test many chemicals but have seen limited use in the regulatory arena, in part because of the need to undergo rigorous, time-consuming formal validation. ...

314

APPROACH TO ENVIRONMENTAL RISK ASSESSMENT USING AVIAN TOXICITY TESTS (JOURNAL VERSION)  

EPA Science Inventory

Toxicity tests results are often condensed into a single endpoint (LC50) to facilitate their use in environmental management. The single number cannot distinguish between two tests with equal LC50s but dissimilar slopes at LC50 and it cannot describe the response at low and high ...

315

Use of tracheal organ cultures in toxicity testing.  

PubMed Central

Fragments of tracheal epithelium alone or in continuity with connective tissues, can be maintained in culture medium and used for short term or long term studies of toxicity of a variety of chemicals. Large numbers of uniform cultures are prepared with the aid of a slicing device or by application of simple method for dissecting sheets of epithelium free from underlying cartilage. The cultures may be placed in an exposure chamber-incubator mounted on a microscope stage and monitored continually for ciliostasis and exfoliation of cells. Morphology is further studied by fixation of selected specimens and preparation for light microscopy and electron microscopy. Synthetic functions are evaluated by autoradiographic measurement of incorporation of radioactive precursors into macromolecules and other dynamic features are indirectly assessed by histochemical and histoenzymatic methods. Short-term studies using these several techniques have shown that ciliostasis does not correlate with cell injury in all instances, and a long-term study has demonstrated dose dependence of a cytotoxic agent when duration of culture viability is measured. The method lends itself to a broad range of investigations in which dose, period of exposure, and role of cofactors must be independently and quantitatively assessed. Images FIGURE 1. FIGURE 2. FIGURE 3. FIGURE 4. FIGURE 5. FIGURE 6. FIGURE 7. FIGURE 8. FIGURE 9. FIGURE 10. FIGURE 11. FIGURE 12. PMID:1017423

Lane, B P; Miller, S L; Drummond, E J

1976-01-01

316

Considerations related to the use of toxicity testing in Canada`s ocean disposal program  

SciTech Connect

As part of its Ocean Disposal Program, Environment Canada is proposing the use of sediment and porewater toxicity tests to evaluate the acceptability of estuarine and marine sediments for ocean disposal. Under a tiered testing approach, sediments which fail the regulated chemical limits would be subjected to toxicity testing using 5 different type of tests: a 10-day amphipod acute test, a bacterial bioluminescence test, an echinoid fertilization test, a 28-day bioaccumulation test and a polychaete growth test which is still in development. In the past year, the use of the first four of these tests in ocean disposal projects on Canada`s west and east coasts has generated several issues which need to be addressed. Among these is the need for more guidance on the selection of reference sediments and on the selection of appropriate test species. Also, the interpretation of toxicity due to unregulated parameters such as sulfides and ammonia must be considered. Pass/fail criteria based on sound scientific rationale must be established to justify land confinement or capping of sediments, and a weight-of-evidence approach (e.g. Triad) using site-specific studies should be considered to support the results of laboratory tests. Techniques such as Ecological Risk Assessment should be considered to predict potential biological effects at an ocean dump site.

Riebel, P. [BEAK Consultants Ltd., Dorval, Quebec (Canada); Rowland, A. [Dept. of Fisheries and Ocean, Vancouver, British Columbia (Canada); Samant, H. [PWGS Canada, Halifax, Nova Scotia (Canada); Doe, K. [Environment Canada, Dartmouth, Nova Scotia (Canada)

1995-12-31

317

Current Development in Reproductive Toxicity Testing of Pesticides  

EPA Science Inventory

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 Asses...

318

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2010 CFR

...50 percent of the flask volume. (iii) Cleaning and sterilization. New test containers may contain substances which inhibit...chemical. (v) Nutrient medium. (A) Formulation and sterilization of nutrient medium used for algal culture and...

2010-07-01

319

40 CFR 797.1330 - Daphnid chronic toxicity test.  

Code of Federal Regulations, 2011 CFR

...parameters are measured at specified intervals in selected test chambers. Data...values and associated 95 percent confidence limits for adult immobilization...and corresponding 95 percent confidence intervals shall also be...

2011-07-01

320

Can laboratory toxicity tests explain the pattern of field communities of algae, plants, and invertebrates along a toxicity gradient of post-mining sites?  

Microsoft Academic Search

The responses of soil algae, vascular plants, and invertebrates to soils collected along a toxicity gradient of post-mining sites were measured in laboratory toxicity tests, and the responses were compared with field pattern of communities of these organisms along this gradient. The study was performed in the Sokolov coal mining district (Czech Republic) where three types of soil materials were

Jan Frouz; Kristýna Hr?ková; Jan Lána; Václav Krišt?fek; Ond?ej Mudrák; Alena Lukešová; Martin Mihaljevi?

2011-01-01

321

Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects  

USGS Publications Warehouse

Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.

Buchwalter, D.B.; Cain, D.J.; Clements, W.H.; Luoma, S.N.

2007-01-01

322

Consensus report on the future of animal-free systemic toxicity testing.  

PubMed

Since March 2013, animal use for cosmetics testing for the European market has been banned. This requires a renewed view on risk assessment in this field. However, in other fields as well, traditional animal experimentation does not always satisfy requirements in safety testing, as the need for human-relevant information is ever increasing. A general strategy for animal-free test approaches was outlined by the US National Research Council`s vision document for Toxicity Testing in the 21st Century in 2007. It is now possible to provide a more defined roadmap on how to implement this vision for the four principal areas of systemic toxicity evaluation: repeat dose organ toxicity, carcinogenicity, reproductive toxicity and allergy induction (skin sensitization), as well as for the evaluation of toxicant metabolism (toxicokinetics) (Fig. 1). CAAT-Europe assembled experts from Europe, America and Asia to design a scientific roadmap for future risk assessment approaches and the outcome was then further discussed and refined in two consensus meetings with over 200 stakeholders. The key recommendations include: focusing on improving existing methods rather than favoring de novo design; combining hazard testing with toxicokinetics predictions; developing integrated test strategies; incorporating new high content endpoints to classical assays; evolving test validation procedures; promoting collaboration and data-sharing of different industrial sectors; integrating new disciplines, such as systems biology and high throughput screening; and involving regulators early on in the test development process. A focus on data quality, combined with increased attention to the scientific background of a test method, will be important drivers. Information from each test system should be mapped along adverse outcome pathways. Finally, quantitative information on all factors and key events will be fed into systems biology models that allow a probabilistic risk assessment with flexible adaptation to exposure scenarios and individual risk factors. PMID:25061899

Leist, Marcel; Hasiwa, Nina; Rovida, Costanza; Daneshian, Mardas; Basketter, David; Kimber, Ian; Clewell, Harvey; Gocht, Tilman; Goldberg, Alan; Busquet, Francois; Rossi, Anna-Maria; Schwarz, Michael; Stephens, Martin; Taalman, Rob; Knudsen, Thomas B; McKim, James; Harris, Georgina; Pamies, David; Hartung, Thomas

2014-01-01

323

Development of marine sediment bioassays and toxicity tests for monitoring and regulation in Europe  

SciTech Connect

There is a need in Europe and elsewhere for a broad suite of whole-sediment bioassays and toxicity tests which can be used for routine monitoring and assessment of the marine environment and for evaluating the toxic effects of chemicals which may find their way into sediments. Until recently, few European species had been incorporated into such tests but the availability of suitable methodologies is now increasing rapidly. Perhaps the most important recent activity in this area consisted of an international ring test of acute sediment toxicity test methods which was organized by the Oslo and Paris Commissions in 1993, using up to 4 offshore chemicals as test materials. It evaluated the performance of 4 acute (5--10 day) tests involving: the sea urchin Echinocardium cordatum, the bivalve mollusc Abra alba, the amphipod crustacean Corophium volutator, and the polychaete worm Arenicola marina. The ring test concluded that the C. volutator test was the most appropriate for evaluating offshore chemicals, but all these methods are now widely used in Europe, both as toxicity tests and as bioassays. For example, the A. marina procedure (which has both lethal and sublethal endpoints), in combination with the C. volutator method, is now routinely used in the UK for monitoring the toxicity of estuarine sediments. Further activities are in progress. Perhaps the most important is the development of chronic marine sediment tests and bioassays which can be used to assess the long-term effects of the many sedimentary contaminants which are able to persist in this type of habitat and possibly cause delayed effects on the growth and reproduction, etc. of benthic fauna.

Thain, J.; Matthiessen, P.

1995-12-31

324

Refinery water (intake and effluent) quality: Update of 1970s with 1990s toxicity testing  

SciTech Connect

The quality of two separate refinery intake waters and effluents was investigated: Petro-Canada (Oakville) and Novacor (Corunna Operations). This study comprised eight different test organized and 22 different toxicity end points, was built on and complemented pioneering 1970s work at the Petro-Canada refinery, and was designed to (a) determine any changes in effluent quality, (b) determine any previously unsuspected effluent toxicity, and (c) determine any potential for chronic toxicity in the effluent. Although Petro-Canada has steadily reduced contaminants in its effluent since the earlier study, toxicity has not changed and no new toxic effects were identified. Effect thresholds for the most sensitive animal species (Daphnia pulex) were 1 to 10% effluent in both studies. The Novacor effluent had lesser effects on biota than the Petro-Canada effluent. Intake waters demonstrated toxicity in some tests. Chronic effects on invertebrates and fish in receiving waters are predicted not to occur in the Novacor effluent is diluted 10- to 20-fold and the Petro-Canada effluent is diluted 50- to 100-fold.

Chapman, P.M.; Paine, M.D. (EVS Environment Consultants, Vancouver, British Columbia (Canada)); Moran, T. (Pollutech Environmental Ltd., Sarnia, Ontario (Canada)); Kierstead, T. (Novacor Chemicals Ltd., Sarnia, Ontario (Canada))

1994-06-01

325

Screening the toxicity of phosphorous-removal adsorbents using a bioluminescence inhibition test.  

PubMed

When found in excess, phosphorus (P) has been linked to surface water eutrophication. As a result, adsorbents are now used in P remediation efforts. However, possible secondary toxicological impacts on the use of new materials for P removal from surface water have not been reported. This study evaluated the toxicity of adsorbent materials used in the removal of P from surface water including: fly ash, bottom ash, alum sludge, a proprietary mix of adsorbents, and a proprietary engineered material. Toxicity screening was conducted by performing solid-liquid extractions (SLEs) followed by the bacterial bioluminescence inhibition test with a Microtox® M500. Of the materials tested, the samples extracted at lower pH levels demonstrated higher toxicity. The material exhibiting the most toxic response was the iron and aluminum oxide coated engineered material registering a 66-67% 15-min EC50 level for pH 4 and 5 SLEs, respectively. However, for SLEs prepared at pH 7, toxic effects were not detected for this engineered material. Fly ash and bottom ash demonstrated between 82 and 84% 15-min EC50 level, respectively, for pH 4 SLE conditions. Dried alum sludge and the proprietary mix of adsorbents were classified as having little to no toxicity. © 2014 Wiley Periodicals, Inc. Environ Toxicol, 2014. PMID:25348491

Duranceau, Steven J; Biscardi, Paul G; Barnhill, Danielle K

2014-10-28

326

Sensitivity of screening-level toxicity tests using soils from a former petroleum refinery  

SciTech Connect

The authors tested five composite soil samples from a former refinery. The samples included a reference soil (Mineral Oil and Grease, MO and G < 40 ppm), thermally-treated soil, biotreated soil, and two untreated soils. They evaluated toxicity using the earthworm E. foetida, lettuce, cress, barley, Microtox, green algae, fathead minnow, and D. magna. The endpoints measured were lethality, seed germination, root elongation, growth, and bioluminescence. Toxicity, as measured by the number of positive responses, increased as follows: biotreated soil < untreated soil No. 1 < reference soil < thermally-treated soil and untreated soil No. 2. The biotreated soil generated only one positive response, whereas the thermally-treated soil and untreated soil No. 2 generated five positive responses. The most sensitive and discriminant terrestrial endpoint was lettuce root elongation which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was barley seed germination for which no toxicity was detected. The most sensitive and discriminant aquatic endpoint was green algae growth which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was D. magna for which no toxicity was detected. Overall, soil and aqueous extract toxicity was spotty and no consistent patterns emerged to differentiate the five soils. Biotreatment significantly reduced the effects of the contamination. Aqueous toxicity was measured in the reference soil, probably because of the presence of unknown dissolved compounds in the aqueous extract. Finally, clear differences in sensitivity existed among the test species.

Pauwels, S.; Bureau, J.; Roy, Y.; Allen, B.; Robidoux, P.Y.; Soucy, M.

1995-12-31

327

Effects of physiochemical properties of test media on nanoparticle toxicity to Daphnia magna Straus.  

PubMed

The physicochemical property of standard test media significantly influenced the aggregation and dissolution of Ag, CuO and ZnO nanoparticles (NPs) and the toxicity of the NPs to Daphnia magna. For all the NPs, the highest amount of metal ions was released from the ISO medium, whereas acute toxicity to D. magna was highest in the moderately hard water medium (EC50 = 4.94, 980, and 1,950 ?g L(-1) for Ag, CuO, and ZnO, respectively). By comparing EC50 values based on the total and dissolved concentrations of NPs with those of metal salt solutions, we found that both particulate and dissolved fractions were likely responsible for the toxicity of Ag NPs, whereas the dissolved fraction mostly contributed to the toxicity of CuO and ZnO NPs. PMID:25063370

Seo, Jaehwan; Kim, Soyoun; Choi, Seona; Kwon, Dongwook; Yoon, Tae-Hyun; Kim, Woo-Keun; Park, June-Woo; Jung, Jinho

2014-09-01

328

Visible Embryo  

NSDL National Science Digital Library

a comprehensive resource of information on human development from conception to birth, designed for both medical student and interested lay people. The Visible Embryo offers a detailed pictorial account of normal and abnormal development.

Carmen Arbona (Mouseworks)

2006-01-30

329

Morphing Embryos  

NSDL National Science Digital Library

Quicktime movies morph human, pig, fish and chick embryos. from Odyssey of Life, Nova Online. No explanation of what is developing, only VERY small morphing movies of early development. Low detail, no explanation.

NOVA Online, Odyssey of Life (WGBH Audience and Member Services)

2005-11-14

330

Whole effluent toxicity (WET) tests on wastewater treatment plants with Daphnia magna and Selenastrum capricornutum.  

PubMed

Whole effluent toxicity (WET) tests, with Daphnia magna and Selenastrum capricornutum, were introduced to evaluate the biological toxicities of effluents from the wastewater treatment plants (WWTPs) in Korea. In WET tests of WWTPs effluents, 33.3% (33/99) for D. magna and 92.6% (75/81) for S. capricornutum revealed greater than 1 toxic unit (TU), even though all the treatment plants investigated were operating in compliance with the regulations, as assessed using conventional monitoring methods (i.e., BOD and total concentration of N or P, etc). There were only minor differences in toxicities according to the types of influents (municipal and agro-industrial) in all treatment plants. However, the effluents treated by an activated sludge treatment process were found to exhibit significantly lower toxicity than those treated by rotating biological contactor (RBC) and extended aeration processes. The seasonal variations in the toxicity were lower in the summer compared to winter, which may have been due to the rainfall received to the sewage intake system during the former period. The impact of WET on river water was also investigated based on the discharge volume. At sites A and B, the total impact of toxicity to stream and river waters was observed to be 70.9% and 90.4% for D. magna and S. capricornutum, respectively. The other four small treatment plants (sites F, G, H and I), with relative discharging volumes between 0.001 and 0.002, contribute less than 1% to the total toxicity. PMID:17106776

Ra, Jin Sung; Kim, Hyun Koo; Chang, Nam Ik; Kim, Sang Don

2007-06-01

331

Development of a biopolymer nanoparticle-based method of oral toxicity testing in aquatic invertebrates.  

PubMed

Aquatic toxicity testing generally focuses on the water absorption/dermal route of exposure to potential toxic chemicals, while much less work has been done on the oral route of exposure. This is due in part to the difficulties of applying traditional oral toxicity testing to aquatic environments, including the tendency for test chemicals to dissolve into water. The use of biopolymer nanoparticles to encapsulate test chemicals onto food to prevent dissolution is one solution presented herein. The biopolymers zein and chitosan were explored for their previously known nanoparticle-forming abilities. Nanoparticles containing the test chemical rhodamine B were formed, applied as films to coat food, and then fed to the test organism, the freshwater amphipod Hyalella azteca. In feeding trials both zein and chitosan nanoparticles showed a significantly lower release rate of rhodamine B into water than food dyed with rhodamine B without biopolymer nanoparticles. Zein nanoparticles also showed better retention ability than chitosan nanoparticles. Both kinds of nanoparticles showed no significant effect on the survival, growth, or feeding behavior of H. azteca. Thus these biopolymers may be an effective system to encapsulate and deliver chemicals to aquatic invertebrates without interfering with common toxicity assessment endpoints like survival and growth. PMID:24726933

Gott, Ryan C; Luo, Yangchao; Wang, Qin; Lamp, William O

2014-06-01

332

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

Code of Federal Regulations, 2013 CFR

...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...specific antiserum to neutralize the vaccine virus in the product. Each lot of antiserum shall be demonstrated by virus neutralization tests not to inhibit...

2013-01-01

333

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

Code of Federal Regulations, 2010 CFR

...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...specific antiserum to neutralize the vaccine virus in the product. Each lot of antiserum shall be demonstrated by virus neutralization tests not to inhibit...

2010-01-01

334

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

Code of Federal Regulations, 2014 CFR

...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...specific antiserum to neutralize the vaccine virus in the product. Each lot of antiserum shall be demonstrated by virus neutralization tests not to inhibit...

2014-01-01

335

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

Code of Federal Regulations, 2011 CFR

...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...specific antiserum to neutralize the vaccine virus in the product. Each lot of antiserum shall be demonstrated by virus neutralization tests not to inhibit...

2011-01-01

336

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

Code of Federal Regulations, 2012 CFR

...INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS...specific antiserum to neutralize the vaccine virus in the product. Each lot of antiserum shall be demonstrated by virus neutralization tests not to inhibit...

2012-01-01

337

Ecotoxicity of aged uranium in soil using plant, earthworm and microarthropod toxicity tests.  

PubMed

Discrepancies about probable no effect concentrations (PNEC) for uranium in soils may be because toxicity tests used freshly contaminated soils. This study used 3 soils amended with a range of uranium concentrations 10 years previously. The toxicity tests with northern wheatgrass (Elymus lanceolatus); earthworm (Eisenia andrei) were not affected below ~1,000 mg U kg(-1), and the soil arthropod Folsomia candida was not affected below ~350 mg U kg(-1). Survival of Orthonychiurus folsomi was diminished 20% (EC(20)) by ~85-130 mg U kg(-1), supporting a PNEC in the range of 100-250 mg U kg(-1) as derived previously. PMID:22033655

Sheppard, S C; Stephenson, G L

2012-01-01

338

AQUATIC TOXICITY TESTS TO CHARACTERIZE THE HAZARD OF VOLATILE ORGANIC CHEMICALS IN WATER: A TOXICITY DATA SUMMARY. PARTS 1 AND 2  

EPA Science Inventory

This summary presents acute and chronic toxicity test data and bioconcentration factors compiled over a 2-year period on fish and invertebrates exposed to several representative chemicals from 5 chemical classes (chlorinated ethanes, chlorinated benzenes, chlorinated ethylenes, c...

339

Relating results from earthworm toxicity tests to agricultural soil  

USGS Publications Warehouse

The artificial soil tests of the European Economic Community and of the Organization for Economic Cooperation produce data relating earthworm mortality to pesticide concentrations in soil under laboratory conditions. To apply these results to agricultural soils it is necessary to relate these concentrations to amounts of pesticide applied per area. This paper reviews the relevant published literature and suggests a simple relation for regulatory use. Hazards to earthworms from pesticides are suggested to be greatest soon after application, when the pesticides may be concentrated in a soil layer a few millimeters thick. For estimating exposure of earthworms, however, a thicker soil layer should be considered, to account for their movement through soil. During favorable weather conditions, earthworms belonging to species appropriate to the artificial soil test have been reported to confine their activity to a layer about 5 cm. If a 5-cm layer is accepted as relevant for regulatory purposes, then an application of 1 kg/ha would be equivalent to 1-67 ppm (dry) in the artificial soil test.

Beyer, W.N.

1992-01-01

340

Developmental toxicity screening in zebrafish.  

PubMed

Given the ever-increasing toxic exposure ubiquitously present in our environment as well as emerging evidence that these exposures are hazardous to human health, the current rodent-based regulations are proving inadequate. In the process of overhauling risk assessment methodology, a nonrodent test organism, the zebrafish, is emerging as tractable for medium- and high-throughput assessments, which may help to accelerate the restructuring of standards. Zebrafish have high developmental similarity to mammals in most aspects of embryo development, including early embryonic processes, and on cardiovascular, somite, muscular, skeletal, and neuronal systems. Here, we briefly describe the development of these systems and then chronicle the toxic impacts assessed following chemical exposure. We also compare the available data in zebrafish toxicity assays with two databases containing mammalian toxicity data. Finally, we identify gaps in our collective knowledge that are ripe for future studies. PMID:21671351

McCollum, Catherine W; Ducharme, Nicole A; Bondesson, Maria; Gustafsson, Jan-Ake

2011-06-01

341

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana  

PubMed Central

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes3. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation4. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol. PMID:22525984

Manfra, Loredana; Savorelli, Federica; Pisapia, Marco; Magaletti, Erika; Cicero, Anna Maria

2012-01-01

342

Increased RO concentrate toxicity following application of antiscalants - Acute toxicity tests with the amphipods Gammarus pulex and Gammarus roeseli.  

PubMed

In reverse osmosis, a frequently used technology in water desalination processes, wastewater (RO concentrate) is generated containing the retained solutes as well as so-called antiscalants (AS), i.e. chemical substances that are commonly applied to prevent membrane-blocking. In this study, a risk assessment of a possible discharge of concentrate into a small stream was conducted. The acute toxicity of two concentrates containing two different ASs and of concentrate without AS to the amphipods Gammarus pulex and Gammarus roeseli was studied. Mortality of gammarids exposed to the concentrate without AS was not different to the control, whereas concentrates including ASs caused mortality rates up to 100% at the highest test concentrations after 168 h. Resulting EC50-values were 36.2-39.4% (v/v) after 96 h and 26.6-58.0% (v/v) after 168 h. These results suggest that the ecotoxicological relevance of antiscalants is greater than currently assumed. PMID:25476491

Feiner, Mona; Beggel, Sebastian; Jaeger, Nadine; Geist, Juergen

2014-12-01

343

COMPARISON OF THE EC50S OF ALGAL TOXICITY TESTS CALCULATED BY FOUR METHODS  

EPA Science Inventory

EC50s (calculated concentrations that would inhibit growth by 50%) of 21 pesticides in unicellular algal toxicity tests were calculated by straight-line graphical interpolation, moving average interpolation, probit analysis and the binomial method. EC50s of 18 tin compounds were ...

344

High Throughput Prioritization for Integrated Toxicity Testing Based on ToxCast Chemical Profiling  

EPA Science Inventory

The rational prioritization of chemicals for integrated toxicity testing is a central goal of the U.S. EPA?s ToxCast? program (http://epa.gov/ncct/toxcast/). ToxCast includes a wide-ranging battery of over 500 in vitro high-throughput screening assays which in Phase I was used to...

345

Fireflies in the Coalmine: Luciferase Technologies in Next-Generation Toxicity Testing  

EPA Science Inventory

Whole-animal studies have been the mainstay of toxicity testing for decades. These approaches are too expensive and laborious to effectively characterize all of the chemicals currently in commercial use. In addition, there are social and ethical pressures to reduce, refine and re...

346

USE OF THE GRASS SHRIMP 'PALAEMONETES PUGIO' IN A LIFE-CYCLE TOXICITY TEST  

EPA Science Inventory

A methodology for using the estuarine grass shrimp (Palaemonetes pugio) in life-cycle toxicity tests was successfully developed. Life-cycle exposures of juvenile shrimp (12 to 19 mm in rostrum-telson length) to the chlorinated hydrocarbon pesticide endrin were begun in November 1...

347

The Future of Toxicity Testing - the NRC Vision and EPA?s ToxCast Program  

EPA Science Inventory

The EPA requested the National Research Council (NRC) to develop a vision and strategic plan for toxicity testing in the 21st century. The 2007 report called for transforming toxicology to provide a robust scientific basis for assessing adverse health effects of environmental age...

348

IMPLICATIONS FOR TOXICITY TESTS WITH AMPHIPOD GAMMARUS AEQUICAUDA: EFFECTS OF TEMPERATURE AND SALINITY ON LIFE CYCLE  

Microsoft Academic Search

This study explored the effect of temperature and salinity on the life cycle of Gammarus aequicauda in order to establish temperature and salinity ranges advantageous for chronic toxicity testing. A broad range of salinity?temperature conditions (salinities of 10, 20 and 36‰ and temperatures of 10, 18 and 24°C combined in nine different treatments) significantly influenced various reproductive aspects of G.

E. Prato; F. Biandolino; C. Scardicchio

2008-01-01

349

Modeling Reproductive Toxicity for Chemical Prioritization into an Integrated Testing Strategy  

EPA Science Inventory

The EPA ToxCast research program uses a high-throughput screening (HTS) approach for predicting the toxicity of large numbers of chemicals. Phase-I tested 309 well-characterized chemicals in over 500 assays of different molecular targets, cellular responses and cell-states. Of th...

350

Comparative Toxicity of Eight Oil Dispersant Products on Two Gulf of Mexico Aquatic Test Species  

EPA Science Inventory

This report is the first of a round of toxicity testing data for eight oil dispersants that have been authorized for use on the National Contingency Plan (NCP) Product Schedule, which is a list of authorized dispersants and other chemicals that may be used to respond to oil disch...

351

ROAD-SALT TOXICITY OF SELECT MICHIGAN WETLAND MACROINVERTEBRATES UNDER DIFFERENT TESTING CONDITIONS  

Microsoft Academic Search

This study determined lethal dose levels of road salt on selected macroinvertebrates from a Michigan, USA wetland under different testing conditions and related those levels to in situ chloride con- centrations of standing water habitats along multi-lane highways. We conducted simultaneous acute (24 and 96 h) and chronic (15 d) toxicity experiments using laboratory containers, containers adjacent to a wetland,

M. Eric Benbow; Richard W. Merritt

2004-01-01

352

PREDICTION OF POPULATION-LEVEL RESPONSE FROM MYSID TOXICITY TEST DATA USING POPULATION MODEL TECHNIQUES  

EPA Science Inventory

Acute and chronic bioassay statistics are used to evaluate the toxicity and the risks of chemical stressors to mysid shrimp Americamysis bahia (formerly Mysidopsis bahia). These include LC50 values from acute tests, chronic values (the geometric mean of the no-obsderved-effect co...

353

Acute toxicity of Cd in stream invertebrates in relation to pH and test design  

Microsoft Academic Search

The acute toxicity of Cd to three stream invertebrates (Baetis rhodani Pict., Leptophlebia marginata (L.) and Pisidium sp.) was tested at pH 5 and 7 simultaneously in static (ST) and flow through (FT) systems. In the static design, the animals were kept individually in small boxes containing aerated stream water. In the flow through system, the three species were kept

A. Gerhardt

1992-01-01

354

Acute toxicity of metals and reference toxicants to a freshwater ostracod, Cypris subglobosa Sowerby, 1840 and correlation to EC(50) values of other test models.  

PubMed

The ostracod Cypris subglobosa Sowerby, 1840 static bioassay test on the basis of a 48h of 50% of immobilization (EC(50)) has been used to measure the toxicity of 36 metals and metalloids and 12 reference toxicants. Among the 36 metals and metalloids, osmium (Os) was found to be the most toxic in the test while boron (B), the least toxic. The EC(50) values of this study revealed positive linear relationship with the established test models of cladoceran (Daphnia magna), sludge worm (Tubifex tubifex), chironomid larvae (Chironomus tentans), protozoan (Tetrahymena pyriformis), fathead minnow (Pimephales promelas), bluegill sunfish (Lepomis macrochirus), and aquatic macrophyte duckweed (Lemna minor). Correlation coefficients (r(2)) for 17 physicochemical properties of metals or metal ions and EC(50)s (as pM) were examined by linear regression analysis. The electronegativity, ionization potential, melting point, solubility product of metal sulfides (pK(sp)), softness parameter and some other physicochemical characteristics were significantly correlated with EC(50)s of metals to C. subglobosa. The reproducibility of toxicity test was determined using 12 reference toxicants. The coefficient of variability of the EC(50)s ranged from 6.95% to 55.37% and variability was comparable to that noticed for D. magna and other aquatic test models. The study demonstrated the need to include crustacean ostracods in a battery of biotests to detect the presence of hazardous chemicals in soils, sewage sludges, sediments and aquatic systems. PMID:19683870

Khangarot, B S; Das, Sangita

2009-12-30

355

Biochemical markers of contamination in fish toxicity tests.  

PubMed

Markers of xenobiotic metabolization (cytochrome P450, ethoxyresorufin-O-deethylase, glutathione and glutathione-S-transferase) were investigated in the liver of the common carp Cyprinus carpio after 28-day exposure to different pesticide formulations.The fish exposed to herbicide Sencor 70 WG (metribuzin 700 g/kg) of 0.25 and 2.5 mg/l showed no change in cytochrome P450 and activity of ethoxyresorufin-O-deethylase when compared to control.Successor 600 (pethoxamid 600 g/l) of 0.06; 0.22 and 0.60 mg/l did not affect either cytochrome P450 or the activity of ethoxyresorufin-O-deethylase. However, in fish exposed to Successor 600 of 0.22 and 0.60 mg/l, there was a rise in glutathione and in the activity of glutathione-S-transferase (p<0.05), with Spearman's correlation r = 0.23 at p<0.05.Spartakus (prochloraz 450 g/l) of 0.36 and 1.08 mg/l induced cytochrome P450 and ethoxyresorufin-O-deethylase (p<0.05), with Spearman's correlation r=0.49 at p<0.01. Glutathione increased in fish exposed to 1.08 mg/l (p<0.05), the activity of glutathione-S-transferase rose (p<0.05) in all concentrations tested (0.108; 0.36 and 1.08 mg/l). Spearman's correlation between glutathione and GST was r=0.38; p<0.01).The obtained data contribute to a better understanding of detoxification of the selected xenobitics in fish. Although biomarkers of the first phase of metabolization are considered to be more sensitive, our results indicate higher sensitivity of the second phase biomarkers. PMID:21753904

Haluzová, Ivana; Modrá, Helena; Blahová, Jana; Havelková, Marcela; Siroká, Zuzana; Svobodová, Zde?ka

2011-06-01

356

Biochemical markers of contamination in fish toxicity tests  

PubMed Central

Markers of xenobiotic metabolization (cytochrome P450, ethoxyresorufin-O-deethylase, glutathione and glutathione-S-transferase) were investigated in the liver of the common carp Cyprinus carpio after 28-day exposure to different pesticide formulations. The fish exposed to herbicide Sencor 70 WG (metribuzin 700 g/kg) of 0.25 and 2.5 mg/l showed no change in cytochrome P450 and activity of ethoxyresorufin-O-deethylase when compared to control. Successor 600 (pethoxamid 600 g/l) of 0.06; 0.22 and 0.60 mg/l did not affect either cytochrome P450 or the activity of ethoxyresorufin-O-deethylase. However, in fish exposed to Successor 600 of 0.22 and 0.60 mg/l, there was a rise in glutathione and in the activity of glutathione-S-transferase (p<0.05), with Spearman's correlation r = 0.23 at p<0.05. Spartakus (prochloraz 450 g/l) of 0.36 and 1.08 mg/l induced cytochrome P450 and ethoxyresorufin-O-deethylase (p<0.05), with Spearman's correlation r=0.49 at p<0.01. Glutathione increased in fish exposed to 1.08 mg/l (p<0.05), the activity of glutathione-S-transferase rose (p<0.05) in all concentrations tested (0.108; 0.36 and 1.08 mg/l). Spearman's correlation between glutathione and GST was r=0.38; p<0.01). The obtained data contribute to a better understanding of detoxification of the selected xenobitics in fish. Although biomarkers of the first phase of metabolization are considered to be more sensitive, our results indicate higher sensitivity of the second phase biomarkers. PMID:21753904

Haluzová, Ivana; Modrá, Helena; Blahová, Jana; Havelková, Marcela; Široká, Zuzana; Svobodová, Zde?ka

2011-01-01

357

Does the survivorship of activated resting stages in toxic environments provide cues for ballast water treatment?  

Microsoft Academic Search

The toxic effects of three inorganic metals (Cu, Cr, Hg), three organic (phenol, formalin, ammonium) chemicals, ozone-enriched water and peroxides (H2O2) on embryonic development were tested in 8 species from the Porifera, Bryozoa and Crustacea. Toxicants with lower molecular weight showed stronger negative impacts on post-diapause embryos than chemicals with higher molecular weight if related to the toxicity of the

Victor Alekseev; Andrey Makrushin; Jiang-Shiou Hwang

2010-01-01

358

Critique on the use of the standardized avian acute oral toxicity test for first generation anticoagulant rodenticides  

USGS Publications Warehouse

Avian risk assessments for rodenticides are often driven by the results of standardized acute oral toxicity tests without regards to a toxicant's mode of action and time course of adverse effects. First generation anticoagulant rodenticides (FGARs) generally require multiple feedings over several days to achieve a threshold concentration in tissue and cause adverse effects. This exposure regimen is much different than that used in the standardized acute oral toxicity test methodology. Median lethal dose values derived from standardized acute oral toxicity tests underestimate the environmental hazard and risk of FGARs. Caution is warranted when FGAR toxicity, physiological effects, and pharmacokinetics derived from standardized acute oral toxicity testing are used for forensic confirmation of the cause of death in avian mortality incidents and when characterizing FGARs' risks to free-ranging birds.

Vyas, Nimish B.; Rattner, Barnett A.

2012-01-01

359

Influence of salinity on fertilization and larval development toxicity tests with two species of sea urchin.  

PubMed

Sea urchin embryo-larval development (ELD) and fertilization tests have been widely used in ecotoxicity studies and are included in regulatory frameworks. Biological processes occur naturally within a range of salinity that depends on the species considered. In an attempt to determine the optimum range of salinity, ELD and fertilization bioassays were performed at different salinities (15-40.5‰) with two species of Atlantic sea urchin: Arbacia lixula and Paracentrotus lividus. In the ELD assay, the optimum range of salinity was wider for A. lixula (29-35.5‰) than for P. lividus (29-33‰). In the fertilization assay with P. lividus as a bioindicator species, the highest percentage of fertilization (90%) was obtained at salinities of between 29 and 33‰. More research on A. lixula is required, since the fertilization success was below 60%. The results of the present study demonstrate that salinity may be a confounding factor in interpreting ELD test results. PMID:21945655

Carballeira, C; Martín-Díaz, L; Delvalls, T A

2011-10-01

360

Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests  

SciTech Connect

Sediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P [>=] 0.05) but did reduce growth in all three test species and in two species at the lowest tested densities, equivalent to 1,460 worms per square meter. At densities of Tubifex tubifex equivalent to 20,000 m[sup [minus]2], the growth of Chironomus riparius was reduced by >90%, Hyalella azteca by >60%, and Hexagenia limbata by almost 50%. The densities of oligochaetes are equivalent to those found in many contaminated sites. Therefore, it is concluded that the presence of indigenous organisms can confound the interpretation of toxicity test results, based on chronic end points. It is recommended that removal of organisms by considered before toxicity tests are conducted with freshwater sediments from sites with large populations of benthic invertebrates, especially oligochaete worms.

Reynoldson, T.B.; Day, K.E.; Clarke, C.; Milani, D. (National Water Research Inst., Burlington, Ontario (Canada))

1994-06-01

361

Biological interactions and toxicity of nanomaterials in the respiratory tract and various approaches of aerosol generation for toxicity testing.  

PubMed

After deposition in the respiratory tract, nanoparticles exhibit acute, neutrophil-driven inflammatory and oxidative reactions, fibrotic responses and in chronic studies under overload conditions carcinogenic effects, more severely than the microscaled materials of the same chemistry. Besides these effects also known to be induced by microsized particles, nanoparticles principally can translocate from the site of exposure to circulation and become systemically available. This may either increase the toxic outcome (e.g. cardio-vascular effects and potential responses in remote organs) or facilitate an elimination of nanomaterials. For example, in combination with partial dissolution, a strong lung response after a short-term inhalative exposure may be followed by a rapid recovery effect. Mechanistically, in vitro and in vivo tests demonstrated that nanoparticles induce inflammation and oxidative stress after interaction with macrophages and lung epithelial cells; consequently, a cytotoxic and genotoxic potential may exist. The deposition, retention and clearance behaviour of inhaled nanomaterials and the toxic effects observed are decisively dependent on the particle agglomeration status of the aerosol. Two principally different experimental approaches are used for inhalative exposure to nanoparticles: either (1) a basic research-oriented approach using very small aerosol mass concentrations or particle formulations that result in at least partially nanoscaled aerosols; in this way, the potential hazard and the translocation potential for individual nanoparticles can be followed effectively; or (2) exposure scenarios mimicking the occupational situation (risk-oriented) with mostly agglomerated nanoparticles; consequently, the probable risk deriving from incidental/accidental exposure can be assessed more adequately. PMID:22418596

Creutzenberg, Otto

2012-07-01

362

Evaluation of multi-organ DNA damage by comet assay from 28 days repeated dose oral toxicity test in mice: A practical approach for test integration in regulatory toxicity testing  

Microsoft Academic Search

The use of comet assay is not new in the evaluation of genotoxic potential of different agents; however, its broad use in product safety for regulatory testing is a relatively new approach. The present study was aimed to integrate genotoxicity tests (micronucleus and comet assay) in 28days repeated dose oral toxicity of methotrexate (MTX) in mice. MTX was administered at

S. Kushwaha; D. N. Tripathi; A. Vikram; P. Ramarao; G. B. Jena

2010-01-01

363

Assessment of the Integral Toxicity of Aquatic Medium Contamination with Oil and Oil Products Using Bacterial Tests  

Microsoft Academic Search

A biotest kit was used to assess the integral toxicity level of aquatic environment contamination with oil and oil products. The integral toxicity dynamics were also monitored during biodegradation of oil and oil products by an association of oil-degrading strains, including Acinetobacter sp., Mycobacterium flavescens, and Rhodococcussp. The following bacterial tests were used: the bioluminescence (BL) test based on Photobacterium

V. M. Fomchenkov; I. A. Irkhina; I. A. Novikov; B. N. Gurov; V. A. Chugunov; V. P. Kholodenko

2000-01-01

364

Optimizing the performance of Hyalella azteca in chronic toxicity tests: Results of feeding studies with various foods and feeding regimes  

EPA Science Inventory

The freshwater amphipod Hyalella azteca is a common organism used for sediment toxicity testing in the United States and elsewhere. Standard methods for 10-d and 42-d toxicity tests with H. azteca were last revised and published by USEPA/ASTM in 2000. Under the methods in the man...

365

Natural sunlight and residual fuel oils are an acutely lethal combination for fish embryos.  

PubMed

The majority of studies characterizing the mechanisms of oil toxicity in fish embryos and larvae have focused largely on unrefined crude oil. Few studies have addressed the toxicity of modern bunker fuels, which contain residual oils that are the highly processed and chemically distinct remains of the crude oil refinement process. Here we use zebrafish embryos to investigate potential toxicological differences between unrefined crude and residual fuel oils, and test the effects of sunlight as an additional stressor. Using mechanically dispersed oil preparations, the embryotoxicity of two bunker oils was compared to a standard crude oil from the Alaska North Slope. In the absence of sunlight, all three oils produced the stereotypical cardiac toxicity that has been linked to the fraction of tricyclic aromatic compounds in an oil mixture. However, the cardiotoxicity of bunker oils did not correlate strictly with the concentrations of tricyclic compounds. Moreover, when embryos were sequentially exposed to oil and natural sunlight, the bunker oils produced a rapid onset cell-lethal toxicity not observed with crude oil. To investigate the chemical basis of this differential toxicity, a GC/MS full scan analysis was used to identify a range of compounds that were enriched in the bunker oils. The much higher phototoxic potential of chemically distinct bunker oils observed here suggests that this mode of action should be considered in the assessment of bunker oil spill impacts, and indicates the need for a broader approach to understanding the aquatic toxicity of different oils. PMID:20435358

Hatlen, Kristin; Sloan, Catherine A; Burrows, Douglas G; Collier, Tracy K; Scholz, Nathaniel L; Incardona, John P

2010-08-01

366

Microtox toxicity test: detoxification of TNT and RDX contaminated solutions by poplar tissue cultures.  

PubMed

Poplar (Populus deltoidesxnigra DN34) tissue cultures removed 2,4,6-trinitrotoluene (TNT) from an aqueous solution in five days, reducing the toxicity of the solution from highly toxic Microtox EC value to that of the control. 1,3,5-Trinitro-1,3,5-triazacyclohexane (RDX) was taken up by the plant tissue cultures more slowly, but toxicity reduction of the solution was evident. The measurement of toxicity reduction of aqueous solutions containing TNT and RDX was performed using a novel methodology developed for use with the Microtox testing system. Radiolabeled TNT and RDX were used to confirm removal of explosives from hydroponic solutions containing plant tissue cultures and to verify that toxicity did not change in solutions where no plant cultures were present (positive controls). High Performance Liquid Chromatography (HPLC) and Liquid Scintillation Counter (LSC) measurements confirmed removal of TNT and RDX from solutions containing poplar plant tissue cultures and constancy of the plant-free controls. In addition, metabolites were identified in remediated solutions by HPLC, confirming the mechanism by which plants can remediate groundwater, surface water, and soil solutions. PMID:18400248

Flokstra, Brittany R; Aken, Benoit Van; Schnoor, Jerald L

2008-05-01

367

Influence of potentially confounding factors on sea urchin porewater toxicity tests  

USGS Publications Warehouse

The influence of potentially confounding factors has been identified as a concern for interpreting sea urchin porewater toxicity test data. The results from >40 sediment-quality assessment surveys using early-life stages of the sea urchin Arbacia punctulata were compiled and examined to determine acceptable ranges of natural variables such as pH, ammonia, and dissolved organic carbon on the fertilization and embryological development endpoints. In addition, laboratory experiments were also conducted with A. punctulata and compared with information from the literature. Pore water with pH as low as 6.9 is an unlikely contributor to toxicity for the fertilization and embryological development tests with A. punctulata. Other species of sea urchin have narrower pH tolerance ranges. Ammonia is rarely a contributing factor in pore water toxicity tests using the fertilization endpoint, but the embryological development endpoint may be influenced by ammonia concentrations commonly found in porewater samples. Therefore, ammonia needs to be considered when interpreting results for the embryological development test. Humic acid does not affect sea urchin fertilization at saturation concentrations, but it could have an effect on the embryological development endpoint at near-saturation concentrations. There was no correlation between sediment total organic carbon concentrations and porewater dissolved organic carbon concentrations. Because of the potential for many varying substances to activate parthenogenesis in sea urchin eggs, it is recommended that a no-sperm control be included with every fertilization test treatment. ?? 2006 Springer Science+Business Media, Inc.

Carr, R.S.; Biedenbach, J.M.; Nipper, M.

2006-01-01

368

Toxicity of landfill leachate to sea urchin development with a focus on ammonia.  

PubMed

Sea urchin gametes and embryos serve as a model system to evaluate toxicity in the marine environment. In this study, the toxicity of complex chemical mixtures in leachate samples to sea urchin development was examined with a focus on ammonia, which was the main contaminant of concern in most samples. Two rapid tests, the submitochondrial particle function and bacterial luminescence tests, were also used. Ammonia is highly toxic to sea urchin embryos with an EC50 of 1.3 mg l(-1) for the embryos of the Australian sea urchin Heliocidaris tuberculata. Leachate ammonia levels were well above these EC50 concentrations. To assess the contribution of ammonia to leachate toxicity in sea urchin development, we compared the predicted toxic units (PTU) and observed toxic units (OTU) for ammonia for each sample. The PTU/OTU comparison revealed that the sensitivity of the sea urchin embryos to ammonia were altered (enhanced or decreased) by other chemicals in the leachates. This result emphasises the need for parallel chemical analyses and a suite bioassays for evaluating the toxicity of complex and variable chemical mixtures. PMID:18716888

Byrne, Maria; Oakes, Diana J; Pollak, John K; Laginestra, Edwina

2008-12-01

369

Ecologically-based clean-up criteria for nitroaromatic explosives using toxicity test results  

SciTech Connect

A former trinitrotoluene (TNT) production and storage facility was the focus of a Remedial Investigation (RI). Contaminants identified during the RI included 2,4-dinitrotoluene (DNT), 2,6-DNT, and 2,4,6-TNT, PCBs, arsenic, lead and chromium. The Conceptual Site Model determined there to be several complete exposure pathways. One of these identified a route by which soil invertebrate communities could be affected through dermal contact and ingestion of soil contaminants. Maintenance of the soil invertebrate community was chosen as the assessment endpoints for this pathway in the Ecological Risk Assessment. The corresponding measurement endpoint was survival of earthworms in 14-day toxicity tests in which they were exposed to site soils. Seven surficial soil samples were collected from Areas of Concern. Each sample was evaluated for acute toxicity to earthworms using standard USEPA protocols. Chemical concentrations were also measured. An artificial soil was used as the control and diluent to establish the Lethal Concentration (LC{sub 50}) of the test soils to earthworms. From the toxicity test results and the corresponding chemical analysis, a matrix of toxicity and contaminant levels was developed. This table was used to determine a concentration of each contaminant at which no acute lethality would be expected. Lower bounds to the chemical specific LC{sub 50} values were determined and, based on sample-specific toxicity units, appropriate LC{sub 50} values were derived (333 mg/kg 2,4-DNT, 182 mg/kg 2,6-DNT, and 1960 mg/kg 2,4,6TNT). Extrapolation of this level to a chronic No Observable Adverse Effect Level (NOAEL) provided a means of proposing site-specific ecologically based clean-up criteria for the constituents of concern which would be protective of the chosen assessment endpoint.

Duh, D.; Roberts, B.; Buzgo, S. [IT Corp., Somerset, NJ (United States)

1995-12-31

370

Arsenic exposure affects embryo development of sea urchin, Paracentrotus lividus (Lamarck, 1816).  

PubMed

Toxicity tests were performed with embryos of Paracentrotus lividus to investigate the toxicological effect of two arsenic species: arsenate (As(V)), expected to be more toxic, and dimethyl-arsinate (DMA) expected to be less toxic. Exposures to toxicants were performed at different developmental stages in order to identify the most sensitive phase of embryological development. Statistical analysis revealed a high significance of each factor (Molecule, Concentration and Time of exposure) and their interaction for the dependent variable "Percentage of normal-shaped plutei". In particular, the 8 cell stage was the most sensitive to arsenic; at a concentration of 50 ?g L(-1) DMA proved to be more toxic than As(V), resulting in nearly 50 % of normal-shaped plutei against the 74 % recorded for As(V). Starting the administration of arsenic at the morula stage, arsenate proved to be significantly more toxic when compared to DMA. PMID:24077651

Gaion, Andrea; Scuderi, Alice; Pellegrini, David; Sartori, Davide

2013-11-01

371

Assessing the relationship between laboratory whole effluent toxicity test data and in-stream biological communities.  

PubMed

The ability of whole effluent toxicity (WET) tests to predict in-stream effects to periphyton, benthic macroinvertebrates, and fish in a habitat-impaired stream was assessed. Habitat assessment data were useful in interpreting in-stream conditions for periphyton and benthic macroinvertebrates. Various periphyton and macroinvertebrate metrics identified siltation effects as opposed to water quality effects in-stream. Pathogen effects noted in fathead minnow WET tests were not reflected in the fish community. Overall, in-stream biological conditions confirmed the absence of water quality-related effects as predicted by WET tests. PMID:19009223

Hall, Scott; Beeson, Dave; Kinsey, Mark; Heise, Liza; Lockwood, Rick

2009-03-01

372

Modified whole effluent toxicity test to assess and decouple wastewater effects from environmental gradients.  

PubMed

Environmental gradients and wastewater discharges produce aggregated effects on marine populations, obscuring the detection of human impact. Classical assessment methods do not include environmental effects in toxicity tests designs, which could lead to incorrect conclusions. We proposed a modified Whole Effluent Toxicity test (mWET) that includes environmental gradients in addition to effluent dilutions, together with the application of Generalized Linear Mixed Models (GLMM) to assess and decouple those effects. We tested this approach, analyzing the lethal effects of wastewater on a marine sandy beach bivalve affected by an artificial canal freshwater discharge used for rice crops irrigation. To this end, we compared bivalve mortality between canal water dilutions (CWd) and salinity controls (SC: without canal water). CWd were prepared by diluting the water effluent (sampled during the pesticide application period) with artificial marine water. The salinity gradient was included in the design by achieving the same final salinities in both CWd and SC, allowing us to account for the effects of salinity by including this variable as a random factor in the GLMM. Our approach detected significantly higher mortalities in CWd, indicating potential toxic effects of the effluent discharge. mWET represents an improvement over the internationally standardized WET tests, since it considers environmental variability and uses appropriate statistical analyses. PMID:23755304

Sauco, Sebastián; Gómez, Julio; Barboza, Francisco R; Lercari, Diego; Defeo, Omar

2013-01-01

373

Brief screening test of ventilatory sensitivity to CO? cannot replace the mandatory test for susceptibility to CNS oxygen toxicity.  

PubMed

Central nervous system oxygen toxicity is a major risk in closed-circuit diving, and the risk increases with elevation of the inspired carbon dioxide (CO2). Mandatory tests for CO2 retention and detection are common practice at the Israel Naval Medical Institute, for the instruction and selection of combat divers at an advanced stage in their training. Read test is a simpler test of the ventilatory response to CO2. Positive correlation between parameters from Read and mandatory tests, enable conducting the test at an earlier stage in diving candidates. In the mandatory test, divers (n = 45) breathing various levels of CO2 in oxygen, and tested for the detection and retention of CO2 reported their sensations. In the Read test, we recorded end-tidal CO2 and ventilation in subjects as they rebreathed from rubber bag. The slope of ventilation was calculated as a function of end-tidal CO2. There was low correlation between any of the parameters from our test and the Read test. There was low insignificant correlation between any parameter from the Read test and detection or retention of CO2. We cannot use the Read test as a test for CO2 retention or detection at an earlier stage in diving candidates. PMID:25102538

Arieli, Ran; Eynan, Mirit; Ofir, Dror; Arieli, Yehuda

2014-08-01

374

Using medaka embryos as a model system to study biological effects of the electromagnetic fields on development and behavior.  

PubMed

The electromagnetic fields (EMFs) of anthropogenic origin are ubiquitous in our environments. The health hazard of extremely low frequency and radiofrequency EMFs has been investigated for decades, but evidence remains inconclusive, and animal studies are urgently needed to resolve the controversies regarding developmental toxicity of EMFs. Furthermore, as undersea cables and technological devices are increasingly used, the lack of information regarding the health risk of EMFs to aquatic organisms needs to be addressed. Medaka embryos (Oryzias latipes) have been a useful tool to study developmental toxicity in vivo due to their optical transparency. Here we explored the feasibility of using medaka embryos as a model system to study biological effects of EMFs on development. We also used a white preference test to investigate behavioral consequences of the EMF developmental toxicity. Newly fertilized embryos were randomly assigned to four groups that were exposed to an EMF with 3.2kHz at the intensity of 0.12, 15, 25, or 60µT. The group exposed to the background 0.12µT served as the control. The embryos were exposed continually until hatch. They were observed daily, and the images were recorded for analysis of several developmental endpoints. Four days after hatching, the hatchlings were tested with the white preference test for their anxiety-like behavior. The results showed that embryos exposed to all three levels of the EMF developed significantly faster. The endpoints affected included the number of somites, eye width and length, eye pigmentation density, midbrain width, head growth, and the day to hatch. In addition, the group exposed to the EMF at 60µT exhibited significantly higher levels of anxiety-like behavior than the other groups did. In conclusion, the EMF tested in this study accelerated embryonic development and heightened anxiety-like behavior. Our results also demonstrate that the medaka embryo is a sensitive and cost-efficient in vivo model system to study developmental toxicity of EMFs. PMID:25084399

Lee, Wenjau; Yang, Kun-Lin

2014-10-01

375

Optimizing the aquatic toxicity assessment under REACH through an integrated testing strategy (ITS).  

PubMed

To satisfy REACH requirements a high number of data on chemical of interest should be supplied to the European Chemicals Agency. To organize the various kinds of information and help the registrants to choose the best strategy to obtain the needed information limiting at the minimum the use of animal testing, integrated testing strategies (ITSs) schemes can be used. The present work deals with regulatory data requirements for assessing the hazards of chemicals to the aquatic pelagic environment. We present an ITS scheme for organizing and using the complex existing data available for aquatic toxicity assessment. An ITS to optimize the choice of the correct prediction strategy for aquatic pelagic toxicity is described. All existing information (like physico-chemical information), and all the alternative methods (like in silico, in vitro or the acute-to-chronic ratio) are considered. Moreover the weight of evidence approach to combine the available data is included. PMID:25262089

Lombardo, Anna; Roncaglioni, Alessandra; Benfenati, Emilio; Nendza, Monika; Segner, Helmut; Jeram, Sonja; Pauné, Eduard; Schüürmann, Gerrit

2014-11-01

376

Effect of methyl tert-butyl ether in standard tests for mutagenicity and environmental toxicity.  

PubMed

Methyl tert-butyl ether (MTBE) is a synthetic compound that is used as a technological solution to problems created by air pollution from vehicle emissions. An important source of MTBE in the environment is leakage from underground storage tanks at gasoline stations or accidents during gasoline transport. The aim of this study was to evaluate the risk of MTBE leakage for the environment using the Microtox (Vibrio fischeri) toxicity test, Lactuca sativa seed germination test, and Ames bacterial mutagenicity test with Salmonella typhimurium his(-) strains TA98, TA100, YG1041, and YG1042, using both standard plate and preincubation protocols. The result of Microtox expressed as EC(50) was 33 mg (MTBE)/L. The effect of all tested MTBE concentration (0.05, 0.50, and 1.00% v/v) on Lactuca sativa roots elongation was negative and proved its toxicity. The highest tested concentration of MTBE that could be tested in Ames test was 3 mg (MTBE)/plate, because of cytotoxicity. No mutagenic response was observed at this or lower concentrations in any of the four strains used. PMID:17091504

Vosahlikova, Miluse; Cajthaml, Tomas; Demnerova, Katerina; Pazlarova, Jarmila

2006-12-01

377

Effects of metal ions and CCl/sub 4/ on sea urchin embryo (Paracentrotus lividus)  

SciTech Connect

The determination of embryotoxicity is an experimental tool for detecting the risks of environmental pollutants. In this study, fertilized eggs of sea urchin have been observed morphologically during exposure to heavy metal salts or carbon tetrachloride, with the purpose of testing possible differences in toxicity of various classes of poisons. Mercuric chloride is the most active salt, still harmful at 0.25 x 10(-6) M, while potassium dichromate, cadmium chloride and lead nitrate block embryo development at concentrations ranging between 0.25 x 10(-4) and 0.25 x 10(-5) M. Carbon tetrachloride per se does not affect the gastrulation at concentrations up to 3,520 ppm, and fails in potentiating the toxicity of the studied metal salts. The selective susceptibility of the development phases of sea urchin embryos to different compounds renders this simple morphological study a sensitive and reliable model for predicting the toxicity of environmental pollutants.

Congiu, A.M.; Calendi, E.; Ugazio, G.

1984-02-01

378

Ecotoxicity of engineered nanoparticles to aquatic invertebrates: a brief review and recommendations for future toxicity testing  

Microsoft Academic Search

Based on a literature review and an overview of toxic effects of engineered nanoparticles in aquatic invertebrates, this paper\\u000a proposes a number of recommendations for the developing field of nanoecotoxicology by highlighting the importance of invertebrates\\u000a as sensitive and relevant test organisms. Results show that there is a pronounced lack of data in this field (less than 20\\u000a peer-reviewed papers

A. Baun; N. B. Hartmann; K. Grieger; K. O. Kusk

2008-01-01

379

First steps in establishing a developmental toxicity test method based on human embryonic stem cells  

Microsoft Academic Search

The use of embryonic stem cells is currently the most promising approach to assess developmental toxicity in vitro. In addition, the possibility of using human embryonic stem (hES) cells will increase safety of consumers and patients as false classification of substances due to inter-species variations can be avoided.One validated test based on murine embryonic stem cells, the embryonic stem cell

Sarah Adler; Cristian Pellizzer; Lars Hareng; Thomas Hartung; Susanne Bremer

2008-01-01

380

CELL DEATH IN RAT AND MOUSE EMBRYOS EXPOSED TO METHANOL IN WHOLEEMBRYO CULTURE  

EPA Science Inventory

Methanol induces developmental toxicity in rats and mice producing exencephaly, cleft palate, cervical ribs, sternebral defects, reduced body weight, and increased embryo/fetal death. xposure to methanol in whole embryo culture also induces developmental retardation, dysmorphogen...

381

METHOD FOR TESTING THE AQUATIC TOXICITY OF SEDIMENT EXTRACTS FOR USE IN IDENTIFYING ORGANIC TOXICANTS IN SEDIMENTS  

EPA Science Inventory

Biologically-directed fractionation techniques are a fundamental tool for identifying the cause of toxicity in environmental samples, but few are available for studying mixtures of organic chemicals in aquatic sediments. This paper describes a method for extracting organic chemic...

382

Development of a suitable test method for evaluating the toxicity of contaminated soils to earthworms in Canada  

SciTech Connect

Environment Canada has embarked on a five year program to develop, standardize, and validate a battery of soil toxicity tests which can be used to assess the relative toxicity of contaminants in soils to terrestrial organisms. These tests must be applicable to soil conditions typically found in Canadian environments and the test species must be representative of the species of soil invertebrates or plants inhabiting soil ecosystems in Canada. One of the toxicity tests being developed is designed to assess the toxicity of contaminated soils to earthworms. Five of the potential test species belong to the Lumbricidae family and include the Canadian worm (Allobophora calignosa/Aporrectodea tuberculate), the European bark worm (Dendrodtilus rubidus (rubida)), the pink soil worm (Eisenia rosea), the red marsh worm (Lumbricus rubellus), and the Canadian night crawler or dew worm (Lumbricus terrestris). The sixth species, the white pot worm (Enchytraeus albidus), belongs to the Enchytraeidae family. Further assessment reduced the number of representative species to three. Most earthworm test methods have been developed to assess the toxicity of chemically-spiked artificial soils to Eisenia fetida or E. andrei. Test methods have also been developed to assess the relative toxicity of contaminated soils from hazardous waste sites. Comparative acute toxicity data for three species of earthworm exposed to a hydrocarbon contamination will be presented. Comparative toxicity data for the same three species of earthworm will also be presented using test procedures and conditions that have been modified to accommodate biological differences among the species of earthworm. Recommendations regarding test design, methods, and conditions optimal for each test species will be summarized and discussed with respect to the precision of test results.

Stephenson, G.L. [Univ. of Guelph, Ontario (Canada); Scroggins, R. [Environment Canada, Gloucester, Ontario (Canada). Method Development and Application Section

1995-12-31

383

Historical Data Analyses and Scientific Knowledge Suggest Complete Removal of the Abnormal Toxicity Test as a Quality Control Test  

PubMed Central

In the early 1900s, the abnormal toxicity test (ATT) was developed as an auxiliary means to ensure safe and consistent antiserum production. Today, the ATT is utilized as a quality control (QC) release test according to pharmacopoeial or other regulatory requirements. The study design has not been changed since around 1940. The evidence of abnormal toxicity testing as a prediction for harmful batches is highly questionable and lacks a scientific rationale. Numerous reviews of historical ATT results have revealed that no reliable conclusions can be drawn from this QC measure. Modern pharmaceutical manufacturers have thorough control of the manufacturing process and comply with good manufacturing practice rules. Contaminants are appropriately controlled by complying with the validated manufacturing processes and strict QC batch release confirming batch-to-batch consistency. Recognizing that product safety, efficacy, and stability can be ensured with strict QC measures, nowadays most regulatory authorities do not require the ATT for most product classes. In line with the replacement, reduction, and refinement (3Rs) initiative, the test requirement has been deleted from approximately 80 monographs of the European Pharmacopoeia and for the majority of product classes in the United States. For these reasons, it is recommended that the ATT should be consistently omitted world-wide and be removed from pharmacopoeias and other regulatory requirements. PMID:25209378

Garbe, Joerg H O; Ausborn, Susanne; Beggs, Claire; Bopst, Martin; Joos, Angelika; Kitashova, Alexandra A; Kovbasenco, OLga; Schiller, Claus-Dieter; Schwinger, Martina; Semenova, Natalia; Smirnova, Lilia; Stodart, Fraser; Visalli, Thomas; Vromans, Lisette

2014-01-01

384

Historical data analyses and scientific knowledge suggest complete removal of the abnormal toxicity test as a quality control test.  

PubMed

In the early 1900s, the abnormal toxicity test (ATT) was developed as an auxiliary means to ensure safe and consistent antiserum production. Today, the ATT is utilized as a quality control (QC) release test according to pharmacopoeial or other regulatory requirements. The study design has not been changed since around 1940. The evidence of abnormal toxicity testing as a prediction for harmful batches is highly questionable and lacks a scientific rationale. Numerous reviews of historical ATT results have revealed that no reliable conclusions can be drawn from this QC measure. Modern pharmaceutical manufacturers have thorough control of the manufacturing process and comply with good manufacturing practice rules. Contaminants are appropriately controlled by complying with the validated manufacturing processes and strict QC batch release confirming batch-to-batch consistency. Recognizing that product safety, efficacy, and stability can be ensured with strict QC measures, nowadays most regulatory authorities do not require the ATT for most product classes. In line with the replacement, reduction, and refinement (3Rs) initiative, the test requirement has been deleted from approximately 80 monographs of the European Pharmacopoeia and for the majority of product classes in the United States. For these reasons, it is recommended that the ATT should be consistently omitted world-wide and be removed from pharmacopoeias and other regulatory requirements. PMID:25209378

Garbe, Joerg H O; Ausborn, Susanne; Beggs, Claire; Bopst, Martin; Joos, Angelika; Kitashova, Alexandra A; Kovbasenco, Olga; Schiller, Claus-Dieter; Schwinger, Martina; Semenova, Natalia; Smirnova, Lilia; Stodart, Fraser; Visalli, Thomas; Vromans, Lisette

2014-11-01

385

A system for conducting flow-through toxicity tests with larval fish  

SciTech Connect

Assessment of toxicological effects in aquatic systems commonly include larval fish 96-h LC50 determinations. The LC50 tests are conducted using static renewal as well as flow-through methods. However, in the case of chemicals with high vapor pressures or fugacity, static renewal methods may produce inconsistent results arising from the pulsed nature of exposure. In addition, in exposures involving these types of compounds, the fluctuation in concentration that can occur between renewals is unlike most exposure scenarios in nature. For these reasons, flow-through systems are often preferable. The authors report here on an inexpensive, easily constructed, flow-through system for toxicant exposure of small organisms. Data are presented to illustrate the capacity of the system to maintain uniform toxicant concentrations relative to static renewal methods.

Diamond, S.A.; Oris, J.T.; Guttman, S.I. [Miami Univ., Oxford, OH (United States). Dept. of Zoology

1995-08-01

386

Developmental toxicity of low generation PAMAM dendrimers in zebrafish  

SciTech Connect

Biological molecules and intracellular structures operate at the nanoscale; therefore, development of nanomedicines shows great promise for the treatment of disease by using targeted drug delivery and gene therapies. PAMAM dendrimers, which are highly branched polymers with low polydispersity and high functionality, provide an ideal architecture for construction of effective drug carriers, gene transfer devices and imaging of biological systems. For example, dendrimers bioconjugated with selective ligands such as Arg-Gly-Asp (RGD) would theoretically target cells that contain integrin receptors and show potential for use as drug delivery devices. While RGD-conjugated dendrimers are generally considered not to be cytotoxic, there currently exists little information on the risks that such materials pose to human health. In an effort to compliment and extend the knowledge gleaned from cell culture assays, we have used the zebrafish embryo as a rapid, medium throughput, cost-effective whole-animal model to provide a more comprehensive and predictive developmental toxicity screen for nanomaterials such as PAMAM dendrimers. Using the zebrafish embryo, we have assessed the developmental toxicity of low generation (G3.5 and G4) PAMAM dendrimers, as well as RGD-conjugated forms for comparison. Our results demonstrate that G4 dendrimers, which have amino functional groups, are toxic and attenuate growth and development of zebrafish embryos at sublethal concentrations; however, G3.5 dendrimers, with carboxylic acid terminal functional groups, are not toxic to zebrafish embryos. Furthermore, RGD-conjugated G4 dendrimers are less potent in causing embryo toxicity than G4 dendrimers. RGD-conjugated G3.5 dendrimers do not elicit toxicity at the highest concentrations tested and warrant further study for use as a drug delivery device.

King Heiden, Tisha C.; Dengler, Emelyne [Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI 53705 (United States); Kao, Weiyuan John [Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Department of Biomedical Engineering, College of Engineering, University of Wisconsin, Madison, WI 53705 (United States); Heideman, Warren [Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI 53705 (United States); Peterson, Richard E. [Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin, Madison, WI 53705 (United States); Molecular and Environmental Toxicology Center, University of Wisconsin, Madison, WI 53705 (United States)], E-mail: repeterson@pharmacy.wisc.edu

2007-11-15

387

Multimodal label-free in vitro toxicity testing with digital holographic microscopy  

NASA Astrophysics Data System (ADS)

Common in vitro toxicity tests of drugs, chemicals or nanomaterials involves the measurement of cellular endpoints like stress response, cell viability, proliferation or cell death. The assay systems determine enzyme activity or protein expression by optical read out of enzyme substrates or marker protein labeling. These standard procedures have several disadvantages. Cellular processes have to be stopped at a distinct time point for the read out, where usually only parts of the cells were affected by the treatment with substances. Typically, only one parameter is analyzed and detection of cellular processes requires several time consuming incubations and washing steps. Here we have applied digital holographic microscopy (DHM) for a multimodal label-free analysis of drug toxicity. NIH 3T3 cells were incubated with 1 ?M Taxol for 24 h. The recorded quantitative phase images were analyzed for cell thickness, cell volume, dry mass and cell migration. Taxol treated cells showed rapidly decreasing cell motility as measure of cell viability. A short increase in cell thickness and dry mass indicated cell division and growth in control cells, whereas Taxol treatment resulted in a continuous increase in cell height followed by a rapid decrease and a decrease of dry mass as indicators of cell death. Multimodal DHM analysis of drug treatment by multiple parameters allows direct and label-free detection of several toxicity parameters in parallel. DHM can quantify cellular reactions minimally invasive over a long time period and analyze kinetics of delayed cellular responses. Our results demonstrate digital holographic microscopy as a valuable tool for multimodal toxicity testing.

Rommel, Christina E.; Dierker, Christian; Vollmer, Angelika; Ketelhut, Steffi; Kemper, Björn; Schnekenburger, Juergen

2014-05-01

388

Standardization of a chronic sediment toxicity test with Chironomus riparius -- An EU collaboration  

SciTech Connect

Because of the need for sensitive measures of low level contaminants in European sediments, a chronic sediment toxicity test method, using Chironomus riparius has been developed as part of a collaborative program for the European Commission. The protocol is a partial life cycle test exposing the animals from egg stage to pre-emergence in sediment-water systems. In 1995 the protocol was ring tested in several laboratories in Europe, the US and Canada using the moth-proofer permethrin as a model substance. This was spiked into a natural sediment using a spiking protocol also developed in this program. Results of the ring test and details of the protocols will be presented.

Fleming, R.; Grootelaar, L.; Guchte, C. van de [WRc Medmenham, Marlow (United Kingdom); [RIZA, Lelystad (Netherlands)

1995-12-31

389

The added value of the 90-day repeated dose oral toxicity test for industrial chemicals with a low (sub)acute toxicity profile in a high quality dataset.  

PubMed

A survey conducted on the EU Notification of New Substances (NONS) database suggested that for industrial chemicals with a profile of low toxicity in (sub)acute toxicity tests there is little added value to the conduct of the 90-day repeated dose study. Avoiding unnecessary animal testing is a central aim of the EU REACH chemicals legislation; therefore we sought to verify the profile using additional data. The OECD's eChemPortal was searched for substances that had both a 28-day and a 90-day study and their robust study summaries were then examined from the ECHA CHEM database. Out of 182 substances with high quality 28-day and 90-day study results, only 18 reported no toxicity of any kind in the (sub)acute tests. However, for 16 of these there were also no reported signs of toxicity at or close to the limit dose (1000mg/kgbw/d) in the 90-day study. Restricting the 'low (sub)acute toxicity in a high quality dataset' profile to general industrial chemicals of no known biological activity, whilst allowing irritant substances, increases the data set and improves the prediction to 95% (20 substances out of 21 substances). The low toxicity profile appears to be of low prevalence within industrial chemicals (10-15%), nevertheless, avoidance of the conduct of a redundant 90-day study for this proportion of the remaining REACH phase-in substances would avoid the use of nearly 50,000 animals and save industry 50million Euros, with no impact on the assessment of human health. PMID:24768988

Taylor, Katy; Andrew, David J; Rego, Laura

2014-08-01

390

Potent Phototoxicity of Marine Bunker Oil to Translucent Herring Embryos after Prolonged Weathering  

PubMed Central

Pacific herring embryos (Clupea pallasi) spawned three months following the Cosco Busan bunker oil spill in San Francisco Bay showed high rates of late embryonic mortality in the intertidal zone at oiled sites. Dead embryos developed to the hatching stage (e.g. fully pigmented eyes) before suffering extensive tissue deterioration. In contrast, embryos incubated subtidally at oiled sites showed evidence of sublethal oil exposure (petroleum-induced cardiac toxicity) with very low rates of mortality. These field findings suggested an enhancement of oil toxicity through an interaction between oil and another environmental stressor in the intertidal zone, such as higher levels of sunlight-derived ultraviolet (UV) radiation. We tested this hypothesis by exposing herring embryos to both trace levels of weathered Cosco Busan bunker oil and sunlight, with and without protection from UV radiation. Cosco Busan oil and UV co-exposure were both necessary and sufficient to induce an acutely lethal necrotic syndrome in hatching stage embryos that closely mimicked the condition of dead embryos sampled from oiled sites. Tissue levels of known phototoxic polycyclic aromatic compounds were too low to explain the observed degree of phototoxicity, indicating the presence of other unidentified or unmeasured phototoxic compounds derived from bunker oil. These findings provide a parsimonious explanation for the unexpectedly high losses of intertidal herring spawn following the Cosco Busan spill. The chemical composition and associated toxicity of bunker oils should be more thoroughly evaluated to better understand and anticipate the ecological impacts of vessel-derived spills associated with an expanding global transportation network. PMID:22312421

Incardona, John P.; Vines, Carol A.; Linbo, Tiffany L.; Myers, Mark S.; Sloan, Catherine A.; Anulacion, Bernadita F.; Boyd, Daryle; Collier, Tracy K.; Morgan, Steven; Cherr, Gary N.; Scholz, Nathaniel L.

2012-01-01

391

Zebrafish on a Chip: A Novel Platform for Real-Time Monitoring of Drug-Induced Developmental Toxicity  

PubMed Central

Pharmaceutical safety testing requires a cheap, fast and highly efficient platform for real-time evaluation of drug toxicity and secondary effects. In this study, we have developed a microfluidic system for phenotype-based evaluation of toxic and teratogenic effects of drugs using zebrafish (Danio rerio) embryos and larvae as the model organism. The microfluidic chip is composed of two independent functional units, enabling the assessment of zebrafish embryos and larvae. Each unit consists of a fluidic concentration gradient generator and a row of seven culture chambers to accommodate zebrafish. To test the accuracy of this new chip platform, we examined the toxicity and teratogenicity of an anti-asthmatic agent-aminophylline (Apl) on 210 embryos and 210 larvae (10 individuals per chamber). The effect of Apl on zebrafish embryonic development was quantitatively assessed by recording a series of physiological indicators such as heart rate, survival rate, body length and hatch rate. Most importantly, a new index called clonic convulsion rate, combined with mortality was used to evaluate the toxicities of Apl on zebrafish larvae. We found that Apl can induce deformity and cardiovascular toxicity in both zebrafish embryos and larvae. This microdevice is a multiplexed testing apparatus that allows for the examination of indexes beyond toxicity and teratogenicity at the sub-organ and cellular levels and provides a potentially cost-effective and rapid pharmaceutical safety assessment tool. PMID:24733308

Chen, Zuanguang; Shi, Lijuan; Zhang, Beibei; Pan, Jianbin; Li, Xinchun; Sun, Duanping; Yang, Hongzhi

2014-01-01

392

Egg incubation position affects toxicity of air cell administered PCB 126 (3,3?4,4?,5- pentachlorobiphenyl) in chicken (Gallus domesticus) embryos  

USGS Publications Warehouse

The avian egg is used extensively for chemical screening and determining the relative sensitivity of species to environmental contaminants (e.g., metals, pesticides, polyhalogenated compounds). The effect of egg incubation position on embryonic survival, pipping, and hatching success was examined following air cell administration of polychlorinated biphenyl (PCB) congener 126 (3,3',4,4',5-pentachlorobiphenyl [PCB 126]; 500?2,000 pg/g egg) on day 4 of development in fertile chicken (Gallus gallus) eggs. Depending on dose, toxicity was found to be up to nine times greater in vertically versus horizontally incubated eggs. This may be due to enhanced embryonic exposure to the injection bolus in vertically incubated eggs compared to more gradual uptake in horizontally incubated eggs. Following air cell administration of PCB 126, horizontal incubation of eggs may more closely approximate uptake and toxicity that has been observed with naturally incorporated contaminants. These data have implications for chemical screening and use of laboratory data for ecological risk assessments.

McKernan, M.A.; Rattner, B.A.; Hale, R.C.; Ottinger, M.A.

2007-01-01

393

A FATHEAD MINNOW 'PIMEPHALES PROMELAS' EARLY LIFE STAGE TOXICITY TEST METHOD EVALUATION AND EXPOSURE TO FOUR ORGANIC CHEMICALS  

EPA Science Inventory

A 32-day test was developed at the Environmental Research Laboratory-Duluth for conducting early life stage (ELS) toxicity tests with fathead minnows Pimephales promelas. These test procedures were evaluated by using the prescribed methods to establish estimated maximum acceptabl...

394

Anodonta imbecillis copper sulfate reference toxicant/food test, Clinch River - Environmental Restoration Program (CR-ERP)  

SciTech Connect

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. Two different foods, phytoplankton and YCT-Selenastrum (YCT-S), were tested in side by side tests to compare food quality. Toxicity testing of copper sulfate reference toxicant was conducted from July 6-15, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed LC{sub 50} values of 0.97 and 0.84 mg Cu/L for phytoplankton and YCT-S, respectively. Previously obtained values for phytoplankton tests are 2.02 and 1.12 mg Cu/L. Too few tests have been conducted with copper as the toxicant to determine a normal range of values. Although significant reduction in growth, compared to the phytoplankton control, was seen in all treatments, including the YCT-S Control, the consequence of this observation has not been established. Ninety-day testing of juvenile mussels exhibited large variations in growth within treatment and replicate groups.

Simbeck, D.J.

1997-06-01

395

Use of estuarine water column tests for detecting toxic conditions in ambient areas of the Chesapeake Bay watershed  

SciTech Connect

Various estuarine water column toxicity tests were conducted twice in nine different ambient stations in the Chesapeake Bay watershed over a 2-year period (1991 to 1993) to determine if toxic conditions existed. The following 8-d toxicity tests were conducted: larval sheepshead minnow (Cyprinodon variegatus) survival and growth test; larval grass shrimp (Palaemonetes pugio) survival and growth test; and a copepod (Eurytemora affinis) life-cycle test. During the second year of testing, two 48-h coot clam (Mulinia lateralis) tests were conducted at each station during each testing period. In 1991, the toxicity tests were conducted twice at stations in the Potomac River at Morgantown and Dahlgren, and in the Patapsco River and the Wye River at the Manor House. All of the above tests were conducted during the fall of 1992 and spring of 1993 at two stations in the Wye River, Nanticoke River, and Middle River. Inorganic contaminants, organic contaminants, and water-quality conditions were measured concurrently during the toxicity testing of ambient water. In 1991, reduced growth of sheepshead minnow larvae was reported at both Potomac River stations during the first test. Significant mortality of either the copepod or sheepshead minnow larvae was also reported at the Wye River during both tests. Results from the 1992/93 testing generally showed minimal effects for three of the test species at all stations. Reduced normal shell development was reported for the coot clam at both Middle River stations during the fall and spring tests concurrently with concentrations of various trace metals that exceeded chronic marine water-quality criteria.

Hall, L.W. Jr.; Ziegenfuss, M.C.; Anderson, R.D.; Killen, W.D. Jr. (Univ. of Maryland System, Queenstown, MD (United States))

1995-02-01

396

ELSFVIFR Toxicology 99 (1995) 11-18 Influence of antioxidants on cadmium toxicity of mouse  

E-print Network

ELSFVIFR Toxicology 99 (1995) 11- 18 Influence of antioxidants on cadmium toxicity of mouse, embryos were cultured in medium containing 0.0, 1.O,3.0, or 6.0 PM Cd with or without various antioxidants antioxidants tested were ineffective. Pretreating em- bryos with antioxidants for 24 h prior to exposing them

Omiecinski, Curtis

397

Hormetic Versus Toxic Effects of Vegetable Tannin in a Multitest Study  

Microsoft Academic Search

Tannin from mimosa trees (Acacia sp.) utilized in traditional leather tanning was tested for toxicity in sea urchin (Sphaerechinus granularis and Paracentrotus lividus) embryos and sperm, marine, and freshwater algae (Selenastrum capricornutum and Dunaliella tertiolecta), and Daphnia magna. Based on a two-step tanning procedure used in traditional tanneries, two mimosa tannin preparations, i.e., fresh tannin (FT) and used tannin (UT),

E. De Nicola; M. Gallo; M. Iaccarino; S. Meric; R. Oral; T. Russo; T. Sorrentino; O. Tünay; E. Vuttariello; M. Warnau; G. Pagano

2004-01-01

398

Resistance to chemical stressors in embryo-larval fish from a marine Superfund site  

SciTech Connect

Several recent studies have demonstrated that estuarine fish chronically exposed to polyhalogenated aromatic hydrocarbons (PHAHs) are resistant to effects of those contaminants, as measured both by induction of detoxification enzymes and toxicity. A study was undertaken to examine the phenomenon of resistance to chemical toxicity in F. heteroclitus inhabiting the New Bedford (NBH) Superfund Site which exhibit some of the highest levels of polychlorinated biphenyls (PCBs) in the world. This portion of that study was designed to examine: (a) whether embryo-larvae of NBH are resistant to PHAHs; (b) whether this resistance is restricted to site-related contaminants; and (c) whether this resistance is correlated with reduced responsiveness to cytochrome P450 induction. To investigate the correlation between cytochrome P450 induction and toxic effects in embryo-larval fish, a novel, nondestructive in ovo fluorescence assay for ethoxyresorufin-o-deethylase (EROD) activity was developed. Embryo-larval tests were conducted using whole sediment and aqueous exposures to samples such as PCB and PAH mixtures and single compounds, organic sediment extracts, and methylmercury as a reference toxicant.

Nacci, D.; Coiro, L.; Kuhn-Hines, A.; Munns, W.R. Jr. [Environmental Protection Agency, Narragansett, RI (United States); Cooper, K. [Rutgers Univ., NJ (United States)

1995-12-31

399

Elimination of Whole Effluent Toxicity NPDES Permit Limits through the Use of an Alternative Testing Species and Reasonable Potential Analysis  

SciTech Connect

The cladoceran, Ceriodaphnia dubia (C. dubia), is required by the State of South Carolina to be used in whole effluent toxicity (WET) compliance tests in order to meet limits contained within National Pollutant Discharge Elimination System (NPDES) permits. Westinghouse Savannah River Company (WSRC) experienced WET test failures for no clear reason over a long period of time. Toxicity identification examinations on effluents did not indicate the presence of toxicants; therefore, the WET test itself was brought under suspicion. Research was undertaken with an alternate cladoceran, Daphnia ambigua (D. ambigua). It was determined that this species survives better in soft water, so approval was obtained from regulating authorities to use this ''alternate'' species in WET tests. The result was better test results and elimination of non-compliances. The successful use of D. ambigua allowed WSRC to gain approval from the South Carolina Department of Health and Environmental Control (SCDHEC) to remove WET limits from the NPDES permit.

PAYNE, W.L.

2004-05-24

400

A technique for extracting blood samples from mice in fire toxicity tests  

NASA Technical Reports Server (NTRS)

The extraction of adequate blood samples from moribund and dead mice has been a problem because of the small quantity of blood in each animal and the short time available between the animals' death and coagulation of the blood. These difficulties are particularly critical in fire toxicity tests because removal of the test animals while observing proper safety precautions for personnel is time-consuming. Techniques for extracting blood samples from mice were evaluated, and a technique was developed to obtain up to 0.8 ml of blood from a single mouse after death. The technique involves rapid exposure and cutting of the posterior vena cava and accumulation of blood in the peritoneal space. Blood samples of 0.5 ml or more from individual mice have been consistently obtained as much as 16 minutes after apparent death. Results of carboxyhemoglobin analyses of blood appeared reproducible and consistent with carbon monoxide concentrations in the exposure chamber.

Bucci, T. J.; Hilado, C. J.; Lopez, M. T.

1976-01-01

401

Acute toxicity of 31 different nanoparticles to zebrafish (Danio rerio) tested in adulthood and in early life stages – comparative study  

PubMed Central

At present, nanoparticles are beginning to influence our lives in many ways and understanding the environmental health and safety aspect of nanomaterials has become a crucial issue. The aim of the work was to assess and compare the acute toxicity of 31 different nanomaterials to fish mature individuals Danio rerio with that to fish early life stages on using evaluation of the 48- and 96- hour LC50 values. A further aim was to evaluate teratogenicity of the nanoparticles tested to fish eggs. The nanoparticles tested were: 8 pure metals, 10 metal oxides, 5 other metal compounds and their mixtures, 2 silicon compounds, 3 calcium compounds, and 3 carbon compounds. Using 48-h and 96-h tests of acute toxicity (according to OECD 203), we evaluated mortality data, LC50 values, occurrence of malformations, as well as hatching time. In our study, 6 kinds of nanoparticles – calcium oxide, copper, copper in the form of oxide and CuZnFe4O4, magnesium oxide, and nickel – caused cumulative mortality. Two kinds of nanoparticles – copper and silver – were toxic for fish with LC50 values of approximately 3 mg/L. We did not observe marked differences between the 48-hour and 96-hour acute toxicity LC50 values, yet the possibility to evaluate hatching time in the 96-h acute fish toxicity test seems to be an advantage against that of the 48-hour toxicity. PMID:24179431

Kovrižnych, Jevgenij A.; Zeljenková, Dagmar; Rollerová, Eva; Szabová, Elena; Wimmerová, So?a

2013-01-01

402

Determination of acute and early life stage toxicity of fat-plant effluent using zebrafish (Danio rerio).  

PubMed

The present study examines the effects of an effluent from a fat plant (FP) on zebrafish (Danio rerio) embryos and larvae using the whole effluent toxicity testing methods (WET). The method is based on acute toxicity using 96-h larval mortality and chronic toxicity using endpoints such as the time to hatch, hatching success, deformity, growth rate, swim-up failure, accumulative mortality, and sex ratio. On the basis of larval mortality the 96-h LC(50) (the concentration was lethal to 50% of newly hatching zebrafish larvae) was 68.9%. In chronic toxicity test, newly fertilized embryos (<5-h old) were exposed to 1, 6, 12, 25, 50% effluent concentrations in a 24-h static renewal system at (27 +/- 0.5) degrees C until 15-day posthatch. The results showed that all chronic endpoints were significantly different from the control at 50% dilution. Embryos began to show lesions on third day at higher concentrations (12, 25, 50% FP effluent concentrations). Treatment group of 25% dilution showed delayed time to hatch. Morphological abnormalities were observed in newly hatched larvae at 25 and 50% FP effluent concentrations. At 25% dilution, sex ratio of larvae was alternated and there was feminization phenomenon. On the basis of the study, the FP effluent tested here may cause increasing embryotoxicity in the zebrafish embryos. We conclude that the test using zebrafish is feasible to evaluate both acute and chronic toxicities of industrial effluents. PMID:18246548

Si?man, Turgay; Incekara, Umit; Yildiz, Yalçin Sevki

2008-08-01

403

Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish  

PubMed Central

Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri), larvae and embryos of zebrafish (Danio rerio) were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v) and 1.95% (v/v) respectively, and embryonic development was inhibited at just 1% (v/v). Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR), while the LC50 of larvae was 75.23% (v/v) and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent. PMID:24995598

Chen, Wenyan; Cai, Qiang; Zhao, Yuan; Zheng, Guojuan; Liang, Yuting

2014-01-01

404

Estuarine sediment acute toxicity testing with the European amphipod Corophium multisetosum Stock, 1952.  

PubMed

This study assessed the use of the European amphipod Corophium multisetosum Stock [Stock, J.H., 1952. Some notes on the taxonomy, the distribution and the ecology of four species of the genus Corophium (Crustacea, Malacostraca). Beaufortia 21, 1-10] in estuarine sediment acute toxicity testing. The sensitivity of adults to the reference toxicant CdCl(2) was determined in water-only 96 h exposures in salinity 2. LC(50) values ranged from 0.33mgCd(2+)L(-1) at 22 degrees C to 0.57mgCd(2+)L(-1) at 15 degrees C. Adult survival was studied in control sediment with water salinity from 0 to 36 and with fine particles content (<63 microm) from 2% to 97% of total sediment, dry weight. Experiments were conducted at 15, 18 and 22 degrees C and the results indicate that the species can be used under the full salinity range although higher mortality was observed at the lower salinity in the higher water temperature, and at the higher salinity in the lower water temperature. The species also tolerated the studied range of sediment fines content and showed the highest sensitivity at intermediate values of fines, especially at the higher temperature, thus advising that tests which have to accommodate sediments with a wide range in fines content should preferably be conducted at 15 degrees C rather than at 22 degrees C. The response in natural sediments was studied in samples collected yearly from 1997 to 2006, at a site located off the Tagus Estuary, western Portugal. A major flood event in winter 2000-2001 induced detectable alterations in sediment baseline descriptors (grain-size, redox potential and total volatile solids), organic contaminants (PAHs, PCBs, DDT metabolites and gamma-HCH) and the macrofauna benthic community. Mortality of the amphipod diminished significantly from the before to the after flood period, in close agreement with diminishing sediment contamination and increasing benthic fauna diversity, in the same time period. C. multisetosum is suitable to conduct acute sediment toxicity tests and presents good potential for the development of a full life-cycle sediment test, due to its amenability to laboratory culture and high survival in the control sediment. PMID:19595433

Ré, Ana; Freitas, Rosa; Sampaio, Leandro; Rodrigues, Ana Maria; Quintino, Victor

2009-09-01

405

Toxicity testing of NCSRP priority substances for the development of soil quality criteria  

SciTech Connect

The effects of 14 National Contaminated Sites Remediation Program (NCSRP) priority substances was measured on emergence and root elongation in lettuce (Lactuca saliva) and radish (Raphanus saliva) and on survival of the earthworm Eisenia foetida. The worm and seedling emergence tests were conducted in an artificial soil mixture composed of 10% peat moss, 20% kaolinite clay, and 70% silica sand (70 mesh) spiked with the contaminant. The root elongation tests were conducted on filter paper moistened with the contaminant solution. The following endpoints were derived on nominal and measured concentrations: NOEC, LOEC, the LC{sub 50} and LC{sub 25} for earthworm mortality and the EC{sub 50} and EC{sub 25} for emergence and root elongation. The contaminants tested included: arsenic, cadmium, chromium, copper, lead, mercury, zinc, vanadium, benzo(a)pyrene, cyanide, naphthalene, ethylene glycol, pentachlorophenol, and phenol. Each test was repeated three times using different batches of freshly prepared soil, seed lots and worm cultures. The authors will present the findings and discuss the application of toxicity test results in developing generic soil quality criteria.

Cureton, P.M. [Environment Canada, Ottawa, Ontario (Canada). Evaluation and Interpretation Branch; Balch, G.; Lintott, D.; Poirrier, K.; Goudey, S. [HydroQual Labs. Ltd., Calgary, Alberta (Canada)

1994-12-31

406

Toxicity assessment of industrial chemicals and airborne contaminants: transition from in vivo to in vitro test methods: a review.  

PubMed

Exposure to occupational and environmental contaminants is a major contributor to human health problems. Inhalation of gases, vapors, aerosols, and mixtures of these can cause a wide range of adverse health effects, ranging from simple irritation to systemic diseases. Despite significant achievements in the risk assessment of chemicals, the toxicological database, particularly for industrial chemicals, remains limited. Considering there are approximately 80,000 chemicals in commerce, and an extremely large number of chemical mixtures, in vivo testing of this large number is unachievable from both economical and practical perspectives. While in vitro methods are capable of rapidly providing toxicity information, regulatory agencies in general are still cautious about the replacement of whole-animal methods with new in vitro techniques. Although studying the toxic effects of inhaled chemicals is a complex subject, recent studies demonstrate that in vitro methods may have significant potential for assessing the toxicity of airborne contaminants. In this review, current toxicity test methods for risk evaluation of industrial chemicals and airborne contaminants are presented. To evaluate the potential applications of in vitro methods for studying respiratory toxicity, more recent models developed for toxicity testing of airborne contaminants are discussed. PMID:16195213

Bakand, S; Winder, C; Khalil, C; Hayes, A

2005-12-01

407

A field assessment of long-term laboratory sediment toxicity tests with the amphipod Hyalella azteca  

USGS Publications Warehouse

Response of the amphipod Hyalella azteca exposed to contaminated sediments for 10 to 42 d in laboratory toxicity tests was compared to responses observed in controlled three-month invertebrate colonization exposures conducted in a pond. Sediments evaluated included a sediment spiked with dichlorodiphenyldichloroethane (DDD) or dilutions of a field sediment collected from the Grand Calumet River (GCR) in Indiana (USA) (contaminated with organic compounds and metals). Consistent effects were observed at the highest exposure concentrations (400 ??g DDD/goc [DDD concentrations normalized to grams of organic carbon (goc) in sedimentl or 4% GCR sediment) on survival, length, and reproduction of amphipods in the laboratory and on abundance of invertebrates colonizing sediments in the field. Effect concentrations for DDD observed for 10-d length and 42-d reproduction of amphipods (e.g., chronic value [ChV] of 66 ??g DDD/goc and 25% inhibition concentration [IC25] of 68 ??g DDD/goc for reproduction) were similar to the lowest effect concentrations for DDD measured on invertebrates colonizing sediment the field. Effect concentrations for GCR sediment on 28-d survival and length and 42-d reproduction and length of amphipods (i.e., ChVs of 0.20-0.66% GCR sediment) provided more conservative effect concentrations compared to 10-d survival or length of amphipods in the laboratory or the response of invertebrates colonizing sediment in the field (e.g., ChVs of 2.2% GCR sediment). Results of this study indicate that use of chronic laboratory toxicity tests with H. azteca and benthic colonization studies should be used to provide conservative estimates of impacts on benthic communities exposed to contaminated sediments. Bioaccumulation of DDD by oligochaetes colonizing the DDD-spiked sediment was similar to results of laboratory sediment tests previously conducted with the oligochaete Lumbriculus variegates, confirming that laboratory exposures can be used to estimate bioaccumulation by oligochaetes exposed in the field. ?? 2005 SETAC.

Ingersoll, C.G.; Wang, N.; Hayward, J.M.R.; Jones, J.R.; Jones, S.B.; Ireland, D.S.

2005-01-01

408

Effects of several variables on whole effluent toxicity test performance and interpretation  

SciTech Connect

Protocol changes and options contained within US Environmental Protection Agency whole effluent toxicity tests represent variables that have the potential to affect bioassay performance and interpretation of results. Variables evaluated in this study include: the change in allowable age in the Pimephales promelas acute bioassay from up to 90 d to a maximum of 14 d, age-specific acute responses of P. promelas among the allowable ages of 1 to 14 d, change in the chronic growth endpoint definition from final mass to biomass, differences between hemacytometer and fluorometer measurements in the Selenastrum capricornutum protocol, and options for statistical interpretation of species sensitivity in multiple test/species screening bioassays. Clear age-related sensitivity and precision differences were observed in acute responses of P. promelas. Results obtained using the younger age classes were typically more variable in studies of both 1- to 14-d-old and 14- to 90-d-old P. promelas. In the experiments on 1- to 14-d-old organisms, larvae at 1 d of age were significantly less sensitive. In the tests on 14- to 90-d-old organisms, the 14-d-old organisms were significantly less sensitive. The change in endpoint definition in the P. promelas chronic bioassay resulted in an apparent increase in toxic response in the inhibition concentration (ICp) value for each bioassay, evaluated by the biomass method, with no general improvement in statistical interest precision estimates and no predictable impact on the no-observed-effect concentration endpoint. Fluorometric scoring in the Selenastrum bioassay was significantly more precise and better capable of estimating counts than hemacytometer measurements. Discrepancies associated with commonly used statistical endpoints used to determine the most sensitive species were identified, and potential solutions were proposed.

Markle, P.J.; Gully, J.R.; Baird, R.B.; Nakada, K.M.; Bottomley, J.P.

2000-01-01

409

Effect-based interpretation of toxicity test data using probability and comparison with alternative methods of analysis  

SciTech Connect

A methodology is described that incorporates the intra- and intertest variability and the biological effect of bioassay data in evaluating the toxicity of single and multiple tests for regulatory decision-making purposes. The single- and multiple-test regulatory decision probabilities were determined from t values (n {minus} 1, one-tailed) derived from the estimated biological effect and the associated standard error at the critical sample concentration. Single-test regulatory decision probabilities below the selected minimum regulatory decision probability identify individual tests as noncompliant. A multiple-test regulatory decision probability is determined by combining the regulatory decision probability of a series of single tests. A multiple-test regulatory decision probability is determined by combining the regulatory decision probability of a series of single tests. A multiple-test regulatory decision probability below the multiple-test regulatory decision minimum identifies groups of tests in which the magnitude and persistence of the toxicity is sufficient to be considered noncompliant or to require enforcement action. Regulatory decision probabilities derived from the t distribution were compared with results based on standard and bioequivalence hypothesis tests using single- and multiple-concentration toxicity test data from an actual national pollutant discharge incorporated the precision of the effect estimate into regulatory decisions at a fixed level of effect. Also, probability-based interpretation of toxicity tests provides incentive to laboratories to produce, and permit holders to use, high-quality, precise data, particularly when multiple tests are used in regulatory decisions. These results are contrasted with standard and bioequivalence hypothesis tests in which the intratest precision is a determining factor in setting the biological effect used for regulatory decisions.

Gully, J.R.; Baird, R.B.; Markle, P.J.; Bottomley, J.P.

2000-01-01

410

Static renewal tests using Anodonta imbecillis (freshwater mussels). Anodonta imbecillis copper sulfate reference toxicant/food test, Clinch River-Environmental Restoration Program (CR-ERP)  

SciTech Connect

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. Two different foods, phytoplankton and YCT-Selenastrum (YCT-S), were tested in side by side tests to compare food quality. Toxicity testing of copper sulfate reference toxicant was conducted from July 6--15, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Although significant reduction in growth, compared to the phytoplankton control, was seen in all treatments, including the YCT-S Control, the consequence of this observation has not been established. Ninety-day testing of juvenile mussels exhibited large variations in growth within treatment and replicate groups. Attachments to this report include: Toxicity test bench sheets and statistical analyses; and Copper analysis request and results.

Simbeck, D.J.

1993-12-31

411

A roadmap for the development of alternative (non-animal) methods for systemic toxicity testing - t4 report*.  

PubMed

Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new products (such as nanoparticles or cell therapies), the limited predictivity of traditional tests for human health effects, duration and costs of current approaches, and animal welfare considerations. The latter holds especially true in the context of the scheduled 2013 marketing ban on cosmetic ingredients tested for systemic toxicity. Based on a major analysis of the status of alternative methods (Adler et al., 2011) and its independent review (Hartung et al., 2011), the present report proposes a roadmap for how to overcome the acknowledged scientific gaps for the full replacement of systemic toxicity testing using animals. Five whitepapers were commissioned addressing toxicokinetics, skin sensitization, repeated-dose toxicity, carcinogenicity, and reproductive toxicity testing. An expert workshop of 35 participants from Europe and the US discussed and refined these whitepapers, which were subsequently compiled to form the present report. By prioritizing the many options to move the field forward, the expert group hopes to advance regulatory science. PMID:22307314

Basketter, David A; Clewell, Harvey; Kimber, Ian; Rossi, Annamaria; Blaauboer, Bas; Burrier, Robert; Daneshian, Mardas; Eskes, Chantra; Goldberg, Alan; Hasiwa, Nina; Hoffmann, Sebastian; Jaworska, Joanna; Knudsen, Thomas B; Landsiedel, Robert; Leist, Marcel; Locke, Paul; Maxwell, Gavin; McKim, James; McVey, Emily A; Ouédraogo, Gladys; Patlewicz, Grace; Pelkonen, Olavi; Roggen, Erwin; Rovida, Costanza; Ruhdel, Irmela; Schwarz, Michael; Schepky, Andreas; Schoeters, Greet; Skinner, Nigel; Trentz, Kerstin; Turner, Marian; Vanparys, Philippe; Yager, James; Zurlo, Joanne; Hartung, Thomas

2012-01-01

412

Using a Sequence Homology-Based Predictive Strategy to Address Current Demands for Focused Toxicity Testing in Ecological Risk Assessment  

EPA Science Inventory

The lack of resources available for comprehensive toxicity testing, international interest in limiting the quantity of animals used in testing, and a mounting list of anthropogenic chemicals produced world-wide have led to the exploration of innovative means for identifying chemi...

413

Commentary on ?Toxicity Testing in the 21st Century: Implications for Human Health Risk Assessment? by Krewski et al.  

EPA Science Inventory

The main goal of Toxicity Testing in the 21st Century: A Vision and A Strategy(1) is to provide a practical means of evaluating the heath risks of chemicals. The vision is in stark contrast to the current situation, where the focus on apical testing in vivo is too expensive and t...

414

ABILITY OF STANDARD TOXICITY TESTS TO PREDICT THE EFFECTS OF THE INSECTICIDE DIFLUBENZURON ON LABORATORY STREAM COMMUNITIES  

EPA Science Inventory

The authors assessed the ability of a standard set of freshwater single species toxicity test to predict accurately effects of the insecticide diflubenzuron (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea) on complex laboratory stream communities. The single-species tests complie...

415

LABORATORY SEDIMENT TOXICITY TESTS, SEDIMENT CHEMISTRY AND DISTRIBUTION OF BENTHIC MACROINVERTEBRATES IN SEDIMENTS FROM THE KEWEENAW WATERWAY, MICHIGAN  

EPA Science Inventory

Acute laboratory sediment toxicity tests using the water flea Daphnia magna and the burrowing mayfly nymph Hexagenia limbata were conducted on sediments from two areas of the Keweenaw Waterway, Michigan, to determine whether the tests reflected the condition of benthic macroinver...

416

Comparative Toxicity of Louisiana Sweet Crude Oil (LSC) and Chemically Dispersed LSC to Two Gulf of Mexico Aquatic Test Species.  

EPA Science Inventory

Environmental Protection Agency released peer reviewed results from the second phase of its independent toxicity testing on mixtures of eight oil dispersants with Louisiana Sweet Crude Oil. EPA conducted the tests as part of an effort to ensure that EPA decisions remain grounded ...

417

Laboratory toxicity test and post-exposure feeding inhibition using the giant freshwater prawn Macrobrachium rosenbergii.  

PubMed

A bioassay was developed using post-larvae of freshwater prawn Macrobrachium rosenbergii (length 9-10 mm) in order to determine the toxicity of profenofos, dimethoate, chlorpyrifos, carbendazim and zinc. This was the first study in the tropics with M. rosenbergii, particularly at the post-larvae stage (9-10 mm) on lethal (LC(50)) and sublethal (EC(50)) effects of toxic substances using post-exposure feeding rate as end point. Median lethal concentrations (LC(50) at 24 and 48 h) were respectively estimated as 11.6 and 9.8 microg L(-1) for profenofos, 142.1 and 102.7 microg L(-1) for dimethoate, 0.7 and 0.3 microg L(-1) for chlorpyrifos, and 439.7 and 329 microg L(-1) for zinc. Effects of carbendazim could not be estimated because carbendazim exposure needs more than 24h exposure period to produce observable effects at the concentrations used. The EC(50) using post-exposure feeding rates determined for profenofos, dimethoate, chlorpyrifos and zinc were 6.023, 269.3, 0.293 and 109.01 microg L(-1), respectively, at 24 h of exposure. Only chlorpyrifos and zinc had LC(50) concentrations greater than the post-exposure feeding EC(50) concentrations. This study demonstrated that the M. rosenbergii could also be used as a test animal to detect the effects of different chemical contaminants in aquatic environments. PMID:19103457

Satapornvanit, Kriengkrai; Baird, D J; Little, D C

2009-03-01

418

Measuring the toxicity of alkyl-phenanthrenes to early life stages of medaka (Oryzias latipes) using partition-controlled delivery.  

PubMed

Alkyl-phenanthrenes are a class of compounds present in crude oil and toxic to developing fish. Most research on alkyl-phenanthrenes has focused on retene (7-isopropyl-1-methyl-phenanthrene), but little is known about the chronic toxicity of related congeners to the early life stages of fish. This project is the first to describe the chronic toxicity of a series of alkyl-phenanthrenes to the embryos of Japanese medaka (Oryzias latipes) using the partition-controlled delivery (PCD) method of exposure and is the first to establish a relationship between toxicity of alkyl-phenanthrenes and log P. With PCD, test concentrations were maintained by equilibrium partitioning of test chemicals from polydimethylsiloxane (PDMS) films containing various concentrations of C1 to C4 phenanthrenes. Log film:solution partition constants (log K(fs)) and aqueous solubility limits were determined for each alkyl-phenanthrene. The prevalence of abnormalities in fish embryos increased in an exposure-dependent manner, with median effective concentration (EC50) values lower than experimental solubility limits of the compounds, and typical of environmental concentrations. Alkyl-phenanthrenes were more toxic to medaka embryos than unsubstituted phenanthrene, with effects resembling those of dioxin and indicating a specific receptor-based mechanism of toxicity. These results extend conclusions for the Exxon Valdez oil spill, suggest a specific mechanism of toxicity for alkyl-phenanthrenes, and provide a model for assessing the risks of mixture toxicity. PMID:21072839

Turcotte, Dominique; Akhtar, Parveen; Bowerman, Michelle; Kiparissis, Yiannis; Brown, R Stephen; Hodson, Peter V

2011-02-01

419

Extending the statistical analysis and graphical presentation of toxicity test results using standardized effect sizes.  

PubMed

The results of repeat-dose toxicity tests are usually presented as tables of means and standard deviations (SDs), with an indication of statistical significance for each biomarker. Interpretation is based mainly on the pattern of statistical significance rather than the magnitude of any response. Multiple statistical testing of many biomarkers leads to false-positive results and, with the exception of growth data, few graphical methods for showing the results are available. By converting means and SDs to standardized effect sizes, a range of graphical techniques including dot plots, line plots, box plots, and quantile-quantile plots become available to show the patterns of response. A bootstrap statistical test involving all biomarkers is proposed to compare the magnitudes of the response between treated groups. These methods are proposed as an extension rather than an alternative to current statistical analyses. They can be applied to published work retrospectively, as all that is required is tables of means and SDs. The methods are illustrated using published articles, where the results range from strong positive to completely negative responses to the test substances. PMID:24487356

Festing, Michael F W

2014-12-01

420

Perspectives on Validation of High-Throughput Assays Supporting 21st Century Toxicity Testing1  

PubMed Central

Summary In vitro, high-throughput screening (HTS) assays are seeing increasing use in toxicity testing. HTS assays can simultaneously test many chemicals, but have seen limited use in the regulatory arena, in part because of the need to undergo rigorous, time-consuming formal validation. Here we discuss streamlining the validation process, specifically for prioritization applications in which HTS assays are used to identify a high-concern subset of a collection of chemicals. The high-concern chemicals could then be tested sooner rather than later in standard guideline bioassays. The streamlined validation process would continue to ensure the reliability and relevance of assays for this application. We discuss the following practical guidelines: (1) follow current validation practice to the extent possible and practical; (2) make increased use of reference compounds to better demonstrate assay reliability and relevance; (3) deemphasize the need for cross-laboratory testing, and; (4) implement a web-based, transparent and expedited peer review process. PMID:23338806

Judson, Richard; Kavlock, Robert; Martin, Matt; Reif, David; Houck, Keith; Knudsen, Thomas; Richard, Ann; Tice, Raymond R.; Whelan, Maurice; Xia, Menghang; Huang, Ruili; Austin, Christopher; Daston, George; Hartung, Thomas; Fowle, John R.; Wooge, William; Tong, Weida; Dix, David

2014-01-01

421

40 CFR 799.9355 - TSCA reproduction/developmental toxicity screening test.  

Code of Federal Regulations, 2013 CFR

...if applicable. (E) Effects on reproduction, including information on mating...The study will provide evaluations of reproduction/developmental toxicity associated...this chapter. (1) OECD (1995). Reproduction/Developmental Toxicity...

2013-07-01

422

40 CFR 799.9355 - TSCA reproduction/developmental toxicity screening test.  

Code of Federal Regulations, 2014 CFR

...if applicable. (E) Effects on reproduction, including information on mating...The study will provide evaluations of reproduction/developmental toxicity associated...this chapter. (1) OECD (1995). Reproduction/Developmental Toxicity...

2014-07-01

423

40 CFR 799.9355 - TSCA reproduction/developmental toxicity screening test.  

Code of Federal Regulations, 2011 CFR

...if applicable. (E) Effects on reproduction, including information on mating...The study will provide evaluations of reproduction/developmental toxicity associated...holidays. (1) OECD (1995). Reproduction/Developmental Toxicity...

2011-07-01

424