Toxicity assessment of reference and natural freshwater sediments with the luminotox assay

CSIR Research Space (South Africa)

Dellamatrice, PM

2006-08-01

Full Text Available to exist between LuminoTox-Solid Phase Assay (Lum-SPA) and Microtox Solid Phase Assay (Mic-SPA) indicating that both tests display a similar toxicity response pattern for CRM sediments having differing contaminant profiles. The sediment elutriate Lum...

Modeling Zebrafish Developmental Toxicity using a Concurrent In vitro Assay Battery (SOT)

Science.gov (United States)

We describe the development of computational models that predict activity in a repeat-dose zebrafish embryo developmental toxicity assay using a combination of physico-chemical parameters and in vitro (human) assay measurements. The data set covered 986 chemicals including pestic...

Pyruvate Decarboxylase Activity Assay in situ of Different Industrial Yeast Strains

Directory of Open Access Journals (Sweden)

Dorota Kręgiel

2009-01-01

Full Text Available Cytoplasmic pyruvate decarboxylase (PDC, EC 4.1.1.1 is one of the key enzymes of yeast fermentative metabolism. PDC is the first enzyme which, under anaerobic conditions, leads to decarboxylation of pyruvate with acetaldehyde as the end product. The aim of this study is to develop a suitable method for PDC activity assay in situ for different industrial yeast strains. Saccharomyces sp. and Debaryomyces sp. yeast strains grew in fermentative medium with 12 % of glucose. Enzymatic assay was conducted in cell suspension treated with digitonin as permeabilisation agent, and with sodium pyruvate as a substrate, at temperature of 30 °C. Metabolites of PDC pathway were detected using gas chromatographic (GC technique. Various parameters like type and molar concentration of the substrate, minimal effective mass fraction of digitonin, cell concentration, reaction time and effect of pyrazole (alcohol dehydrogenase inhibitor were monitored to optimize PDC enzymatic assay in situ. In the concentration range of yeast cells from 1⋅10^7 to 1⋅10^8 per mL, linear correlation between the produced acetaldehyde and cell density was noticed. Only pyruvate was the specific substrate for pyruvate decarboxylase. In the presence of 0.05 M sodium pyruvate and 0.05 % digitonin, the enzymatic reaction was linear up to 20 min of the assay. During incubation, there was no formation of ethanol and, therefore, pyrazole was not necessary for the assay.

A study on the toxicity of three radiosensitizers on retinoblastoma cells by MTT assay

International Nuclear Information System (INIS)

Yi Xianjin; Jin Yizun; Ding Li; Ni Zhou; Wang Wenji

1994-01-01

The toxicity of three radiosensitizers BSO, CM and RSU-1069 on retinoblastoma cells was determined and the efficiency of in vitro MTT assay on drug-screening for retinoblastoma was also evaluated. The results showed that the MTT assay is very useful. The toxicity of radiosensitizers on retinoblastoma cells is dependent on cell line characteristics, drug concentration and time of exposure to it

A FLUORESCENCE BASED ASSAY FOR DNA DAMAGE INDUCED BY TOXIC INDUSTRIAL CHEMICALS

Science.gov (United States)

One of the reported effects for exposure to many of the toxic industrial chemicals is DNA damage. The present study describes a simple, rapid and innovative assay to detect DNA damage resulting from exposure of surrogate DNA to toxic industrial chemicals (acrolein, allylamine, ch...

Rapid in situ assessment for predicting soil quality using an algae-soaked disc seeding assay.

Science.gov (United States)

Nam, Sun-Hwa; Moon, Jongmin; Kim, Shin Woong; Kim, Hakyeong; Jeong, Seung-Woo; An, Youn-Joo

2017-11-16

The soil quality of remediated land is altered and this land consequently exerts unexpected biological effects on terrestrial organisms. Therefore, field evaluation of such land should be conducted using biological indicators. Algae are a promising new biological indicator since they are a food source for organisms in higher soil trophic levels and easily sampled from the soil. Field evaluation of soil characteristics is preferred to be testing in laboratory conditions because many biological effects cannot be duplicated during laboratory evaluations. Herein, we describe a convenient and rapid algae-soaked disc seeding assay for assessing soil quality in the field based on soil algae. The collection of algae is easy and rapid and the method predicts the short-term quality of contaminated, remediated, and amended farm and paddy soils. The algae-soaked disc seeding assay is yet to be extensively evaluated, and the method cannot be applied to loamy sand soil in in situ evaluations. The algae-soaked disc seeding assay is recommended for prediction of soil quality in in situ evaluations because it reflects all variations in the environment. The algae-soaked disc seeding assay will help to develop management strategies for in situ evaluation.

VAPOR SAMPLING DEVICE FOR INTERFACE WITH MICROTOX ASSAY FOR SCREENING TOXIC INDUSTRIAL CHEMICALS

Science.gov (United States)

A time-integrated sampling system interfaced with a toxicity-based assay is reported for monitoring volatile toxic industrial chemicals (TICs). Semipermeable membrane devices (SPMDs) using dimethyl sulfoxide (DMSO) as the fill solvent accumulated each of 17 TICs from the vapor...

In situ assay of nitrate reductase activity using portable water bath

Science.gov (United States)

Adam Rajsz; Bronisław Wojtuń; Andrzej Bytnerowicz

2017-01-01

In environmental research (i.e., plant ecophysiology, environmental microbiology, and environmental chemistry), some assays require incubation of samples at controlled temperature and darkness. Until now, due to a lack of equipment providing such possibility in situ, researchers had to move collected samples to the laboratory for incubation. Obviously, a delayed...

Ecotoxicological evaluation of in situ bioremediation of soils contaminated by the explosive 2,4,6-trinitrotoluene (TNT)

International Nuclear Information System (INIS)

Frische, Tobias

2003-01-01

The luminescent bacteria assay, using soil leachates, was the most sensitive toxicity indicator. - To evaluate the environmental relevance of in situ bioremediation of contaminated soils, effective and reliable monitoring approaches are of special importance. The presented study was conducted as part of a research project investigating in situ bioremediation of topsoils contaminated by the explosive 2,4,6-trinitrotoluene (TNT). Changes in soil toxicity within different experimental fields at a former ordnance factory were evaluated using a battery of five bioassays (plant growth, Collembola reproduction, soil respiration, luminescent bacteria acute toxicity and mutagenicity test) in combination to chemical contaminant analysis. Resulting data reveal clear differences in sensitivities between methods with the luminescent bacteria assay performed with soil leachates as most sensitive toxicity indicator. Complete test battery results are presented in so-called soil toxicity profiles to visualise and facilitate the interpretation of data. Both biological and chemical monitoring results indicate a reduction of soil toxicity within 17 months of remediation

A cell impedance measurement device for the cytotoxicity assay dependent on the velocity of supplied toxic fluid

Science.gov (United States)

Kang, Yoon-Tae; Kim, Min-Ji; Cho, Young-Ho

2018-04-01

We present a cell impedance measurement chip capable of characterizing the toxic response of cells depending on the velocity of the supplied toxic fluid. Previous impedance-based devices using a single open-top chamber have been limited to maintaining a constant supply velocity, and devices with a single closed-top chamber present difficulties in simultaneous cytotoxicity assay for varying levels of supply velocities. The present device, capable of generating constant and multiple levels of toxic fluid velocity simultaneously within a single stepwise microchannel, performs a cytotoxicity assay dependent on toxic fluid velocity, in order to find the effective velocity of toxic fluid to cells for maximizing the cytotoxic effect. We analyze the cellular toxic response of 5% ethanol media supplied to cancer cells within a toxic fluid velocity range of 0-8.3 mm s-1. We observe the velocity-dependent cell detachment rate, impedance, and death rate. We find that the cell detachment rate decreased suddenly to 2.4% at a velocity of 4.4 mm s-1, and that the change rates of cell resistance and cell capacitance showed steep decreases to 8% and 41%, respectively, at a velocity of 5.7 mm s-1. The cell death rate and impedance fell steeply to 32% at a velocity of 5.7 mm s-1. We conclude that: (1) the present device is useful in deciding on the toxic fluid velocity effective to cytotoxicity assay, since the cellular toxic response is dependent on the velocity of toxic fluid, and; (2) the cell impedance analysis facilitates a finer cellular response analysis, showing better correlation with the cell death rate, compared to conventional visual observation. The present device, capable of performing the combinational analysis of toxic fluid velocity and cell impedance, has potential for application to the fine cellular toxicity assay of drugs with proper toxic fluid velocity.

Evaluation of Myc Gene Amplification in Prostate Cancer Using a Dual Color Chromogenic in-Situ Hybridization (Dual CISH) Assay

OpenAIRE

Daniel Lerda; Marta Cabrera; Jorge Flores; Luis Gutierrez; Armando Chierichetti; Martin Revol; Hernan Garcia Onto

2013-01-01

Objetive: The overall purpose of the study was to demonstrate applicability of the Dako dual-color chromogenic in situ hybridization (CISH) assay (DAKO Denmark, Glostrup) with respect to fluorescence in situ hybridization (FISH) probes MYC-C. Methods: MYC gene amplification by FISH and Dako dual-color CISH Results: The study showed that the dual-color CISH assay can convert Texas red and fluorescein isothiocyanate (FITC) signals into chromogenic signals. The dual –color CISH assay was p...

In Situ Estuarine and Marine Toxicity Testing: A Review, Including Recommendations for Future Use in Ecological Risk Assessment

Science.gov (United States)

2009-09-01

field and microcosms than they do under laboratory test conditions. In the case of tributyltin ( TBT ) exposures in San Diego Bay, he found that...TECHNICAL REPORT 1986 September 2009 In Situ Estuarine and Marine Toxicity Testing A Review, Including Recommendations for Future Use in...Pacific TECHNICAL REPORT 1986 September 2009 In Situ Estuarine and Marine Toxicity Testing A Review, Including Recommendations for Future Use in

Building predictive in vitro pulmonary toxicity assays using high-throughput imaging and artificial intelligence.

Science.gov (United States)

Lee, Jia-Ying Joey; Miller, James Alastair; Basu, Sreetama; Kee, Ting-Zhen Vanessa; Loo, Lit-Hsin

2018-06-01

Human lungs are susceptible to the toxicity induced by soluble xenobiotics. However, the direct cellular effects of many pulmonotoxic chemicals are not always clear, and thus, a general in vitro assay for testing pulmonotoxicity applicable to a wide variety of chemicals is not currently available. Here, we report a study that uses high-throughput imaging and artificial intelligence to build an in vitro pulmonotoxicity assay by automatically comparing and selecting human lung-cell lines and their associated quantitative phenotypic features most predictive of in vivo pulmonotoxicity. This approach is called "High-throughput In vitro Phenotypic Profiling for Toxicity Prediction" (HIPPTox). We found that the resulting assay based on two phenotypic features of a human bronchial epithelial cell line, BEAS-2B, can accurately classify 33 reference chemicals with human pulmonotoxicity information (88.8% balance accuracy, 84.6% sensitivity, and 93.0% specificity). In comparison, the predictivity of a standard cell-viability assay on the same set of chemicals is much lower (77.1% balanced accuracy, 84.6% sensitivity, and 69.5% specificity). We also used the assay to evaluate 17 additional test chemicals with unknown/unclear human pulmonotoxicity, and experimentally confirmed that many of the pulmonotoxic reference and predicted-positive test chemicals induce DNA strand breaks and/or activation of the DNA-damage response (DDR) pathway. Therefore, HIPPTox helps us to uncover these common modes-of-action of pulmonotoxic chemicals. HIPPTox may also be applied to other cell types or models, and accelerate the development of predictive in vitro assays for other cell-type- or organ-specific toxicities.

Quantification of hydrolysis of toxic organophosphates and organophosphonates by diisopropyl fluorophosphatase from Loligo vulgaris by in situ Fourier transform infrared spectroscopy.

Science.gov (United States)

Gäb, Jürgen; Melzer, Marco; Kehe, Kai; Richardt, André; Blum, Marc-Michael

2009-02-15

The enzyme diisopropyl fluorophosphatase (DFPase) from the squid Loligo vulgaris effectively catalyzes the hydrolysis of diisopropyl fluorophosphate (DFP) and a number of organophosphorus nerve agents, including sarin, soman, cyclosarin, and tabun. Up to now, the determination of kinetic data has been achieved by techniques such as pH-stat titration, ion-selective electrodes, and fluorogenic substrate analogs. We report a new assaying method using in situ Fourier transform infrared (FTIR) spectroscopy with attenuated total reflection (ATR) for the real-time determination of reaction rates. The method employs changes in the P-O-R stretching vibration of DFP and nerve agent substrates when hydrolyzed to their corresponding phosphoric and phosphonic acids. It is shown that the Lambert-Beer law holds and that changes in absorbance can be directly related to changes in concentration. Compared with other methods, the use of in situ FTIR spectroscopy results in a substantially reduced reaction volume that adds extra work safety when handling highly toxic substrates. In addition, the new method allows the noninvasive measurement of buffered solutions with varying ionic strengths complementing existing methods. Because the assay is independent of the used enzyme, it should also be applicable to other phosphotriesterase enzymes such as organophosphorus hydrolase (OPH), organophosphorus acid anhydrolase (OPAA), and paraoxonase (PON).

Comparison of Acute Toxicity of Algal Metabolites Using Bioluminescence Inhibition Assay

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Hansa Jeswani

2015-01-01

Full Text Available Microalgae are reported to degrade hazardous compounds. However, algae, especially cyanobacteria are known to produce secondary metabolites which may be toxic to flora, fauna and human beings. The aim of this study was selection of an appropriate algal culture for biological treatment of biomass gasification wastewater based on acute toxicity considerations. The three algae that were selected were Spirulina sp., Scenedesmus abundans and a fresh water algal consortium. Acute toxicity of the metabolites produced by these algal cultures was tested at the end of log phase using the standard bioluminescence inhibition assay based on Vibrio fischeri NRRLB 11174. Scenedesmus abundans and a fresh water algal consortium dominated by cyanobacteria such as Phormidium, Chroococcus and Oscillatoria did not release much toxic metabolites at the end of log phase and caused only about 20% inhibition in bioluminescence. In comparison, Spirulina sp. released toxic metabolites and caused 50% bioluminescence inhibition at 3/5 times dilution of the culture supernatant (EC50.

Testing of in situ and ex situ bioremediation approaches for an oil-contaminated peat bog following a pipeline break

International Nuclear Information System (INIS)

Wilson, J.J.; Lee, D.W.; Yeske, B.M.; Kuipers, F.

2000-01-01

The feasibility of treating a 1985 pipeline spill of light Pembina Cardium crude oil at a bog near Violet Grove, Alberta was discussed. Pembina Pipeline Corporation arranged for a treatability test to be conducted on oil-contaminated sphagnum peat moss from the site to determine effective in situ or ex situ remediation options for the site. The test was used to evaluate the biodegradation potential of contaminants. Four tests were designed to simulate field different field treatment approaches and to collect critical data on toxicity and leachability of the peat moss. The tests included a bioslurry test, a soil microcosm test, an aerated water saturated peat column test, and a standard toxicity characteristic leachate potential test. The first three tests gave similar results of at least 74 per cent biodegradation of the residual crude oil on the peat solids and no residual toxicity as measured by the Microtox Assay. It was determined that both in situ bioremediation using an aerated water injection system or an ex situ landfarming approach would achieve required criteria and no fertilizers would be necessary to maintain active bioremediation. The new gas-liquid reactor (GLR) aeration technology used in these tests creates a constant supply of hyperoxygenated water prior to column injection. The continuous release of tiny air bubbles maximizes air surface area and increases the gas transfer rates. 3 tabs., 3 figs

ASSESSMENT OF TOXICITY OF INDUSTRIAL WASTES USING CROP PLANT ASSAYS

OpenAIRE

Carmen Alice Teacă; Ruxanda Bodîrlău

2008-01-01

Environmental pollution has a harmful action on bioresources, including agricultural crops. It is generated through many industrial activities such as mining, coal burning, chemical technology, cement production, pulp and paper industry, etc. The toxicity of different industrial wastes and heavy metals excess was evaluated using crop plant assays (germination and hydroponics seedlings growth tests). Experimental data regarding the germination process of wheat (from two cultivars) and rye seed...

Toxicity assays applied for evaluation of ionizing radiation and zeolites adsorption as treatment technologies for coloured effluent

International Nuclear Information System (INIS)

Higa, Marcela Cantelli

2008-01-01

Textile industry is one raising commercial activity in Brazil. This activity has been generating important environmental interferences such as colour and bad biological effects into aquatic environment. Liquid textile effluents are toxic to lived organisms and may present low biological degradability. Although foreseen at federal regulation, the effluent quality is not controlled by toxicity assays in the country. These assays are carried out to determine the potential effects of chemical substances and effluents to cause negative effects to the exposed organisms. The present work aimed whole toxicity evaluation as well as the applicability of two different treatment techniques: ionizing radiation and zeolite adsorption. The efficacy of them were evaluated using eco toxicity bases and real effluents. Two different industries from Sao Paulo State contributed to this project supplying their real effluents. The samples were collected at a Textile Industry and at a Chemical Industry (dying producer) and after the measurement of whole toxicity the samples were submitted to treatments. Toxicity assays were carried out for Daphnia similis and for Vibrio fischeri. Sample irradiations were performed at an Electron Beam Accelerator at CTR/IPEN. Zeolites treatment is an P and D activity from CQMA/IPEN which contributed to this Project. Zeolites v/ere prepared from fly ash previously being used as an adsorber material. Both treatments (electron irradiation and zeolite adsorption) resulted on important toxicity and colour reduction. Concerning irradiation the effluents from chemical industry required higher radiation doses than that from textile activity. The radiation dose to be suggested is 40 kGy (toxicity reduction > 60%) for the chemical effluents and 0.5 kGy for the textile effluents (toxicity reduction > 90%). When zeolite adsorption was evaluated the Z1M6 resulted in 85%o v/hole toxicity reduction and ZC6 resulted in very low efficiency for the effluents of chemical

In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

Science.gov (United States)

Farag, Aïda M.; Harper, David D.; Skaar, Don

2014-01-01

Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

Automated high-content assay for compounds selectively toxic to Trypanosoma cruzi in a myoblastic cell line.

Directory of Open Access Journals (Sweden)

Julio Alonso-Padilla

2015-01-01

Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, represents a very important public health problem in Latin America where it is endemic. Although mostly asymptomatic at its initial stage, after the disease becomes chronic, about a third of the infected patients progress to a potentially fatal outcome due to severe damage of heart and gut tissues. There is an urgent need for new drugs against Chagas disease since there are only two drugs available, benznidazole and nifurtimox, and both show toxic side effects and variable efficacy against the chronic stage of the disease.Genetically engineered parasitic strains are used for high throughput screening (HTS of large chemical collections in the search for new anti-parasitic compounds. These assays, although successful, are limited to reporter transgenic parasites and do not cover the wide T. cruzi genetic background. With the aim to contribute to the early drug discovery process against Chagas disease we have developed an automated image-based 384-well plate HTS assay for T. cruzi amastigote replication in a rat myoblast host cell line. An image analysis script was designed to inform on three outputs: total number of host cells, ratio of T. cruzi amastigotes per cell and percentage of infected cells, which respectively provides one host cell toxicity and two T. cruzi toxicity readouts. The assay was statistically robust (Z´ values >0.6 and was validated against a series of known anti-trypanosomatid drugs.We have established a highly reproducible, high content HTS assay for screening of chemical compounds against T. cruzi infection of myoblasts that is amenable for use with any T. cruzi strain capable of in vitro infection. Our visual assay informs on both anti-parasitic and host cell toxicity readouts in a single experiment, allowing the direct identification of compounds selectively targeted to the parasite.

Fluorescence-based assay as a new screening tool for toxic chemicals

Science.gov (United States)

Moczko, Ewa; Mirkes, Evgeny M.; Cáceres, César; Gorban, Alexander N.; Piletsky, Sergey

2016-09-01

Our study involves development of fluorescent cell-based diagnostic assay as a new approach in high-throughput screening method. This highly sensitive optical assay operates similarly to e-noses and e-tongues which combine semi-specific sensors and multivariate data analysis for monitoring biochemical processes. The optical assay consists of a mixture of environmental-sensitive fluorescent dyes and human skin cells that generate fluorescence spectra patterns distinctive for particular physico-chemical and physiological conditions. Using chemometric techniques the optical signal is processed providing qualitative information about analytical characteristics of the samples. This integrated approach has been successfully applied (with sensitivity of 93% and specificity of 97%) in assessing whether particular chemical agents are irritating or not for human skin. It has several advantages compared with traditional biochemical or biological assays and can impact the new way of high-throughput screening and understanding cell activity. It also can provide reliable and reproducible method for assessing a risk of exposing people to different harmful substances, identification active compounds in toxicity screening and safety assessment of drugs, cosmetic or their specific ingredients.

Comparative evaluation of genetic toxicity patterns of carcinogens and noncarcinogens: strategies for predictive use of short-term assays

International Nuclear Information System (INIS)

Tennant, R.W.; Spalding, J.W.; Stasiewicz, S.; Caspary, W.D.; Mason, J.M.; Resnick, M.A.

1987-01-01

The results of a recent comprehensive evaluation of the relationship between four measures of in vitro genetic toxicity and the capacity of the chemicals to induce neoplasia in rodents carry some important implications. The results showed that while the Salmonella mutagenesis assay detected only about half of the carcinogenes as mutagens, the other three in vitro assays (mutagenesis in MOLY cells or induction of aberrations or SCEs in CHO cells) did not complement Salmonella since they failed to effectively discriminate between the carcinogens and noncarcinogens found negative in the Salmonella assay. The specificity of the Salmonella assay for this group of 73 chemicals was relatively high (only 4 of 29 noncarcinogens were positive). Therefore, the authors have begun to evaluate in vivo genetic toxicity assays for their ability to complement Salmonella in the identification of carcinogens

Lead toxicity thresholds in 17 Chinese soils based on substrate-induced nitrification assay.

Science.gov (United States)

Li, Ji; Huang, Yizong; Hu, Ying; Jin, Shulan; Bao, Qiongli; Wang, Fei; Xiang, Meng; Xie, Huiting

2016-06-01

The influence of soil properties on toxicity threshold values for Pb toward soil microbial processes is poorly recognized. The impact of leaching on the Pb threshold has not been assessed systematically. Lead toxicity was screened in 17 Chinese soils using a substrate-induced nitrification (SIN) assay under both leached and unleached conditions. The effective concentration of added Pb causing 50% inhibition (EC50) ranged from 185 to >2515mg/kg soil for leached soil and 130 to >2490mg/kg soil for unleached soil. These results represented >13- and >19-fold variations among leached and unleached soils, respectively. Leaching significantly reduced Pb toxicity for 70% of both alkaline and acidic soils tested, with an average leaching factor of 3.0. Soil pH and CEC were the two most useful predictors of Pb toxicity in soils, explaining over 90% of variance in the unleached EC50 value. The relationships established in the present study predicted Pb toxicity within a factor of two of measured values. These relationships between Pb toxicity and soil properties could be used to establish site-specific guidance on Pb toxicity thresholds. Copyright © 2016. Published by Elsevier B.V.

Toxicity screening of soils from different mine areas—A contribution to track the sensitivity and variability of Arthrobacter globiformis assay

Energy Technology Data Exchange (ETDEWEB)

Marques, Catarina R., E-mail: crmarques@ua.pt [Departamento de Biologia and CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Caetano, Ana L. [Departamento de Biologia and CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Haller, Andreas [ECT Oekotoxikologie GmbH, Böttgerstraße 2–14, D-65439 Flörsheim a. M. (Germany); Gonçalves, Fernando [Departamento de Biologia and CESAM (Centro de Estudos do Ambiente e do Mar), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Pereira, Ruth [Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto (Portugal); Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, P 4050-123 Porto (Portugal); Römbke, Jörg [ECT Oekotoxikologie GmbH, Böttgerstraße 2–14, D-65439 Flörsheim a. M. (Germany)

2014-06-01

Highlights: • The assay gave rapid and feasible discrimination of toxic soils to A. globiformis. • Sensitive and low variability response to soils from different regions. • Soil properties may interfere with metal toxicity and fluorescence measurements. • Proposal of a toxicity threshold for the contact assay regarding soils. • A. globiformis assay should be included in the Tier I of risk assessment frameworks. - Abstract: This study used the Arthrobacter globiformis solid-contact test for assessing the quality of soils collected in areas subjected to past and present mine activities in Europe (uranium mine, Portugal) and North Africa (phosphogypsum pile, Tunisia; iron mine, Morocco). As to discriminate the influence of soils natural variability from the effect of contaminants, toxicity thresholds were derived for this test, based on the dataset of each study area. Furthermore, the test sensitivity and variability was also evaluated. As a result, soils that inhibited A. globiformis dehydrogenase activity above 45% or 50% relatively to the control, were considered to be toxic. Despite the soil metal content determined, the properties of soils seemed to influence dehydrogenase activity. Overall, the contact test provided a coherent outcome comparing to other more time-consuming and effort-demanding ecotoxicological assays. Our results strengthened the feasibility and ecological relevance of this assay, which variability was quite reduced hence suggesting its potential integration within the test battery of tier 1 of soil risk assessment schemes.

Toxicity screening of soils from different mine areas—A contribution to track the sensitivity and variability of Arthrobacter globiformis assay

International Nuclear Information System (INIS)

Marques, Catarina R.; Caetano, Ana L.; Haller, Andreas; Gonçalves, Fernando; Pereira, Ruth; Römbke, Jörg

2014-01-01

Highlights: • The assay gave rapid and feasible discrimination of toxic soils to A. globiformis. • Sensitive and low variability response to soils from different regions. • Soil properties may interfere with metal toxicity and fluorescence measurements. • Proposal of a toxicity threshold for the contact assay regarding soils. • A. globiformis assay should be included in the Tier I of risk assessment frameworks. - Abstract: This study used the Arthrobacter globiformis solid-contact test for assessing the quality of soils collected in areas subjected to past and present mine activities in Europe (uranium mine, Portugal) and North Africa (phosphogypsum pile, Tunisia; iron mine, Morocco). As to discriminate the influence of soils natural variability from the effect of contaminants, toxicity thresholds were derived for this test, based on the dataset of each study area. Furthermore, the test sensitivity and variability was also evaluated. As a result, soils that inhibited A. globiformis dehydrogenase activity above 45% or 50% relatively to the control, were considered to be toxic. Despite the soil metal content determined, the properties of soils seemed to influence dehydrogenase activity. Overall, the contact test provided a coherent outcome comparing to other more time-consuming and effort-demanding ecotoxicological assays. Our results strengthened the feasibility and ecological relevance of this assay, which variability was quite reduced hence suggesting its potential integration within the test battery of tier 1 of soil risk assessment schemes

Assaying environmental nickel toxicity using model nematodes

Science.gov (United States)

Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

2013-01-01

Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

Cytotoxicity of Phenol Red in Toxicity Assays for Carbon Nanoparticles

Directory of Open Access Journals (Sweden)

Chunhai Fan

2012-09-01

Full Text Available To explore the novel properties of carbon nanoparticles (CNPs in nanotoxicity assays, the adsorption of phenol red (a pH indicator for culture medium by multi-walled carbon nanotubes (MWNTs and three kinds of carbon blacks (CBs with nanosize, and its effects on cytotoxicity were studied. Results indicated that the phenol red adsorbed and delivered into cells by CBs was responsible for the toxicity to Hela cells in the medium without serum. The cellular uptake of phenol red was verified using 125I-labeling techniques. The size-dependent cytotoxicity of CBs was found to closely correlate to adsorption of phenol red, cellular uptake of phenol red-CB complexes and the amount of phenol red delivered into the cells by CBs. Although the CBs were either nontoxic or slightly toxic, as vehicles of phenol red, they played an essential role in the cytotoxicity induced by phenol red. However, MWNTs showed an intrinsic cytotoxicity independent of phenol red. The implications associated with these findings are discussed.

Toxicity assessment of water at different stages of treatment using Microtox assay

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Pogorzelec Marta

2017-01-01

Full Text Available Number of potentially toxic hydrophobic organic contaminants e.g. polycyclic aromatic hydrocarbons, pesticides, polychlorinated biphenyls and dioxins having entered aquatic environment, including potential sources of drinking water. Unfortunately, not all micropollutants can be removed during water treatment processes. What is more, disinfectants can react with some organic compounds already present in the water, and form disinfection by-products which also can be toxic. The aim of this study was to assess toxicity of water at different stages of water treatment and to verify usefulness semipermeable membrane devices in monitoring of drinking water. For this purpose, semipermeable membrane devices (SPMDs were deployed in a surface water treatment plant. To determine the effect of water treatment on the presence of toxic micropollutants, study was conducted for a period of 5 months. Three sampling places were chosen: raw water input, stream of water just before disinfection and treated water output. After sampling dialysis in organic solvent was carried out and extracts were then analyzed with the Microtox acute toxicity test. The study has indicated the utility as well as some limitations of combining SPMDs with bioluminescence assay in the monitoring of biological effects of bioavailable hydrophobic pollutants in drinking water.

ASSESSMENT OF TOXICITY OF INDUSTRIAL WASTES USING CROP PLANT ASSAYS

Directory of Open Access Journals (Sweden)

Carmen Alice Teacă

2008-11-01

Full Text Available Environmental pollution has a harmful action on bioresources, including agricultural crops. It is generated through many industrial activities such as mining, coal burning, chemical technology, cement production, pulp and paper industry, etc. The toxicity of different industrial wastes and heavy metals excess was evaluated using crop plant assays (germination and hydroponics seedlings growth tests. Experimental data regarding the germination process of wheat (from two cultivars and rye seeds in the presence of industrial wastes (thermal power station ash, effluents from a pre-bleaching stage performed on a Kraft cellulose – chlorinated lignin products or chlorolignin, along with use of an excess of some heavy metals (Zn and Cu are presented here. Relative seed germination, relative root elongation, and germination index (a factor of relative seed germination and relative root elongation were determined. Relative root elongation and germination index were more sensitive indicators of toxicity than seed germination. The toxic effects were also evaluated in hydroponics experiments, the sensitivity of three crop plant species, namely Triticum aestivum L. (wheat, Secale cereale (rye, and Zea mays (corn being compared. Physiological aspects, evidenced both by visual observation and biometric measurements (mean root, aerial part and plant length, as well as the cellulose and lignin content were examined.

Evaluation of Myc Gene Amplification in Prostate Cancer Using a Dual Color Chromogenic in-Situ Hybridization (Dual CISH Assay

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Daniel Lerda

2013-04-01

Full Text Available Objetive: The overall purpose of the study was to demonstrate applicability of the Dako dual-color chromogenic in situ hybridization (CISH assay (DAKO Denmark, Glostrup with respect to fluorescence in situ hybridization (FISH probes MYC-C. Methods: MYC gene amplification by FISH and Dako dual-color CISH Results: The study showed that the dual-color CISH assay can convert Texas red and fluorescein isothiocyanate (FITC signals into chromogenic signals. The dual –color CISH assay was performed on 40 cases of prostate cancer. Amplification was identified in 12 of 40 (30% tumors. No amplification was seen in 28 of 40 (70% tumors. FISH data were available in total of 40 tumors. All tumors showed concordant results between dual-color CISH and FISH for classifying a tumor as MYC amplified or not amplified. Conclusions: We conclude that dual-color Dako CISH assay is an accurate method for determining MYC gene amplification with added advantages that make it a more practically useful method. [J Interdiscipl Histopathol 2013; 1(2.000: 81-84

Bioluminescent Vibrio fischeri assays in the assessment of seasonal and spatial patterns in toxicity of contaminated river sediments

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Sergio Jarque

2016-11-01

Full Text Available Several bacteria-based assays, notably Vibrio fischeri luminescence assays, are often used as environmental monitoring tool for toxicity in sediments that may serve as both sinks and secondary source of contamination in aquatic ecosystems. In this study, we used 30-s kinetic bioassays based on V. fischeri to evaluate the toxicity associated to sediments from five localities with different contamination inputs (Morava River and its tributary Drevnice River in the south-eastern part of the Czech Republic. Toxicity assessed as half maximal inhibitory concentration (IC50 over the course of a year-long sampling was compared in bottom sediments and freshly trapped particulate material. Standard approach based on testing of aqueous elutriates was compared with toxicity of whole sediments (contact suspension toxicity. Bottom sediments showed lower toxicity compared to freshly trapped suspended materials in all cases. On the other hand, standardized elutriates induced generally weaker effects than suspended sediments likely due to losses during the extraction process. Toxicity generally increased during winter reaching maximum peaks in early spring months in all five sites. Total organic carbon (TOC was found to be highly correlated with toxic effects. Toxicity from sites with direct industrial and agricultural water inputs also correlated with concentrations of metals, polycyclic aromatic hydrocarbons (PAHs and polychlorinated biphenyls (PCBs. Single time point sampling followed by the extraction and testing of elutriates, do not truly reflect the spatial and temporal variability in natural sediments and may lead to underestimation of ecotoxic risks.

Assaying environmental nickel toxicity using model nematodes.

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David Rudel

Full Text Available Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water, we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

Acute toxicity assessment of explosive-contaminated soil extracting solution by luminescent bacteria assays.

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Xu, Wenjie; Jiang, Zhenming; Zhao, Quanlin; Zhang, Zhenzhong; Su, Hongping; Gao, Xuewen; Ye, Zhengfang

2016-11-01

Explosive-contaminated soil is harmful to people's health and the local ecosystem. The acute toxicity of its extracting solution was tested by bacterial luminescence assay using three kinds of luminescent bacteria to characterize the toxicity of the soil. An orthogonal test L 16 (4 5 ) was designed to optimize the soil extracting conditions. The optimum extracting conditions were obtained when the ultrasonic extraction time, ultrasonic extraction temperature, and the extraction repeat times were 6 h, 40 °C, and three, respectively. Fourier transform infrared spectroscopy (FTIR) results showed that the main components of the contaminated soil's extracting solution were 2,4-dinitrotoluene-3-sulfonate (2,4-DNT-3-SO 3 - ); 2,4-dinitrotoluene-5-sulfonate (2,4-DNT-5-SO 3 - ); and 2,6-dinitrotoluene (2,6-DNT). Compared with Photobacterium phosphoreum and Vibrio fischeri, Vibrio qinghaiensis sp. Nov. is more suitable for assessing the soil extracting solution's acute toxicity. Soil washing can remove most of the contaminants toxic to luminescent bacterium Vibrio qinghaiensis sp. Nov., suggesting that it may be a potential effective remediation method for explosive-contaminated soil.

In situ and laboratory bioassays with Chironomus riparius larvae to assess toxicity of metal contamination in rivers: the relative toxic effect of sediment versus water contamination.

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Faria, Mafalda S; Lopes, Ricardo J; Nogueira, António J A; Soares, Amadeu M V M

2007-09-01

We used bioassays employing head capsule width and body length increase of Chironomus riparius larvae as end points to evaluate metal contamination in streams. Bioassays were performed in situ near an abandoned Portuguese goldmine in the spring of 2003 and 2004. Bioassays also were performed under laboratory conditions with water and sediment collected from each stream to verify if laboratory bioassays could detect in situ toxicity and to evaluate the relative contribution of sediment and water to overall toxicity. We used field sediments with control water and control sediments with field water to discriminate between metal contamination in water and sediment. Field water with dry and sieved, organic matter-free, and nontreated sediments was used to determine the toxicity of heavy metals that enter the organism through ingested material. In both in situ and laboratory bioassays, body length increase was significantly inhibited by metal contamination, whereas head capsule width was not affected. Body length increase was more affected by contaminated sediment compared to contaminated water. The lowest-effect level of heavy metals was observed in the dry and sieved sediment that prevented ingestion of sediment particles by larvae. These results suggest that body length increase of C. riparius larvae can be used to indicate the impact of metal contamination in rivers. Chironomus riparius larvae are more affected by heavy metals that enter the organism through ingested sediment than by heavy metals dissolved in the water column. Nevertheless, several factors, such as the particle size and organic matter of sediment, must be taken into account.

Investigation of olive mill wastewater (OMW) ozonation efficiency with the use of a battery of selected ecotoxicity and human toxicity assays

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Siorou, Sofia [Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, GR-26500 Patras (Greece); Vgenis, Theodoros T.; Dareioti, Margarita A. [Laboratory of Biochemical Engineering and Environmental Technology, Department of Chemical Engineering, University of Patras, 1 Karatheodori Str., University Campus, GR-26500 Patras (Greece); Vidali, Maria-Sophia; Efthimiou, Ioanna [Department of Environmental and Natural Resources Management, University of Patras, 2 Seferi Str., GR-30100 Agrinio (Greece); Kornaros, Michael [Laboratory of Biochemical Engineering and Environmental Technology, Department of Chemical Engineering, University of Patras, 1 Karatheodori Str., University Campus, GR-26500 Patras (Greece); Vlastos, Dimitris [Department of Environmental and Natural Resources Management, University of Patras, 2 Seferi Str., GR-30100 Agrinio (Greece); Dailianis, Stefanos, E-mail: sdailianis@upatras.gr [Section of Animal Biology, Department of Biology, Faculty of Sciences, University of Patras, GR-26500 Patras (Greece)

2015-07-15

Highlights: • Raw- and ozonated-olive mill wastewater (OMW) toxic effects were investigated. • A battery of biological assays and toxic endpoints were used. • Ozonation for up to 300 min attenuates OMW toxicity, following phenols’ reduction. • Further OMW ozonation (>300 min) could enhance OMW toxicity. • OMW ozonation efficacy depends on OMW-derived intermediates and high NO{sub 3}{sup −}–N levels. - Abstract: The effects of olive mill wastewater (OMW) on a battery of biological assays, before and during the ozonation process, were investigated in order to assess ozone’s efficiency in removing phenolic compounds from OMW and decreasing the concomitant OMW toxicity. Specifically, ozonated-OMW held for 0, 60, 120, 300, 420, 540 min in a glass bubble reactor, showed a drastic reduction of OMW total phenols (almost 50%) after 300 min of ozonation with a concomitant decrease of OMW toxicity. In particular, the acute toxicity test primarily performed in the fairy shrimp Thamnocephalus platyurus (Thamnotoxkit F™ screening toxicity test) showed a significant attenuation of OMW-induced toxic effects, after ozonation for a period of 120 and in a lesser extent 300 min, while further treatment resulted in a significant enhancement of ozonated-OMW toxic effects. Furthermore, ozonated-OMW-treated mussel hemocytes showed a significant attenuation of the ability of OMW to cause cytotoxic (obtained by the use of NRRT assay) effects already after an ozonation period of 120 and to a lesser extent 300 min. In accordance with the latter, OMW-mediated oxidative (enhanced levels of superoxide anions and lipid peroxidation by-products) and genotoxic (induction of DNA damage) effects were diminished after OMW ozonation for the aforementioned periods of time. The latter was also revealed by the use of cytokinesis block micronucleus (CBMN) assay in human lymphocytes exposed to different concentrations of both raw- and ozonated-OMW for 60, 120 and 300 min. Those findings

Oligonucleotide PIK3CA/Chromosome 3 Dual in Situ Hybridization Automated Assay with Improved Signals, One-Hour Hybridization, and No Use of Blocking DNA.

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Zhang, Wenjun; Hubbard, Antony; Baca-Parkinson, Leslie; Stanislaw, Stacey; Vladich, Frank; Robida, Mark D; Grille, James G; Maxwell, Daniel; Tsao, Tsu-Shuen; Carroll, William; Gardner, Tracie; Clements, June; Singh, Shalini; Tang, Lei

2015-09-01

The PIK3CA gene at chromosome 3q26.32 was found to be amplified in up to 45% of patients with squamous cell carcinoma of the lung. The strong correlation between PIK3CA amplification and increased phosphatidylinositol 3-kinase (PI3K) pathway activities suggested that PIK3CA gene copy number is a potential predictive biomarker for PI3K inhibitors. Currently, all microscopic assessments of PIK3CA and chromosome 3 (CHR3) copy numbers use fluorescence in situ hybridization. PIK3CA probes are derived from bacterial artificial chromosomes whereas CHR3 probes are derived mainly from the plasmid pHS05. These manual fluorescence in situ hybridization assays mandate 12- to 18-hour hybridization and use of blocking DNA from human sources. Moreover, fluorescence in situ hybridization studies provide limited morphologic assessment and suffer from signal decay. We developed an oligonucleotide-based bright-field in situ hybridization assay that overcomes these shortcomings. This assay requires only a 1-hour hybridization with no need for blocking DNA followed by indirect chromogenic detection. Oligonucleotide probes produced discrete and uniform CHR3 stains superior to those from the pHS05 plasmid. This assay achieved successful staining in 100% of the 195 lung squamous cell carcinoma resections and in 94% of the 33 fine-needle aspirates. This robust automated bright-field dual in situ hybridization assay for the simultaneous detection of PIK3CA and CHR3 centromere provides a potential clinical diagnostic method to assess PIK3CA gene abnormality in lung tumors. Copyright © 2015 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Evaluation of e-liquid toxicity using an open-source high-throughput screening assay

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Keating, James E.; Zorn, Bryan T.; Kochar, Tavleen K.; Wolfgang, Matthew C.; Glish, Gary L.; Tarran, Robert

2018-01-01

The e-liquids used in electronic cigarettes (E-cigs) consist of propylene glycol (PG), vegetable glycerin (VG), nicotine, and chemical additives for flavoring. There are currently over 7,700 e-liquid flavors available, and while some have been tested for toxicity in the laboratory, most have not. Here, we developed a 3-phase, 384-well, plate-based, high-throughput screening (HTS) assay to rapidly triage and validate the toxicity of multiple e-liquids. Our data demonstrated that the PG/VG vehicle adversely affected cell viability and that a large number of e-liquids were more toxic than PG/VG. We also performed gas chromatography–mass spectrometry (GC-MS) analysis on all tested e-liquids. Subsequent nonmetric multidimensional scaling (NMDS) analysis revealed that e-liquids are an extremely heterogeneous group. Furthermore, these data indicated that (i) the more chemicals contained in an e-liquid, the more toxic it was likely to be and (ii) the presence of vanillin was associated with higher toxicity values. Further analysis of common constituents by electron ionization revealed that the concentration of cinnamaldehyde and vanillin, but not triacetin, correlated with toxicity. We have also developed a publicly available searchable website (www.eliquidinfo.org). Given the large numbers of available e-liquids, this website will serve as a resource to facilitate dissemination of this information. Our data suggest that an HTS approach to evaluate the toxicity of multiple e-liquids is feasible. Such an approach may serve as a roadmap to enable bodies such as the Food and Drug Administration (FDA) to better regulate e-liquid composition. PMID:29584716

Prediction of Chemical Carcinogenicity in Rodents from in vitro Genetic Toxicity Assays

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Tennant, Raymond W.; Margolin, Barry H.; Shelby, Michael D.; Zeiger, Errol; Haseman, Joseph K.; Spalding, Judson; Caspary, William; Resnick, Michael; Stasiewicz, Stanley; Anderson, Beth; Minor, Robert

1987-05-01

Four widely used in vitro assays for genetic toxicity were evaluated for their ability to predict the carcinogenicity of selected chemicals in rodents. These assays were mutagenesis in Salmonella and mouse lymphoma cells and chromosome aberrations and sister chromatid exchanges in Chinese hamster ovary cells. Seventy-three chemicals recently tested in 2-year carcinogenicity studies conducted by the National Cancer Institute and the National Toxicology Program were used in this evaluation. Test results from the four in vitro assays did not show significant differences in individual concordance with the rodent carcinogenicity results; the concordance of each assay was approximately 60 percent. Within the limits of this study there was no evidence of complementarity among the four assays, and no battery of tests constructed from these assays improved substantially on the overall performance of the Salmonella assay. The in vitro assays which represented a range of three cell types and four end points did show substantial agreement among themselves, indicating that chemicals positive in one in vitro assay tended to be positive in the other in vitro assays. To help put this project into its proper context, we emphasize certain features of the study: 1) Standard protocols were used to mimic the major use of STTs worldwide--screening for mutagens and carcinogens; no attempt was made to optimize protocols for specific chemicals. 2) The 73 NTP chemicals and their 60% incidence of carcinogenicity are probably not representative of the universe of chemicals but rather reflect the recent chemical selection process for the NTP carcinogenicity assay. 3) The small, diverse group of chemicals precludes a meaningful evaluation of the predictive utility of chemical structure information. 4) The NTP is currently testing these same 73 chemicals in two in vivo STTs for chromosomal effects. 5) Complete data for an additional group of 30 to 40 NTP chemicals will be gathered on

Fluorescence in situ hybridization in combination with the comet assay and micronucleus test in genetic toxicology

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Hovhannisyan Galina G

2010-09-01

Full Text Available Abstract Comet assay and micronucleus (MN test are widely applied in genotoxicity testing and biomonitoring. While comet assay permits to measure direct DNA-strand breaking capacity of a tested agent MN test allows estimating the induced amount of chromosome and/or genome mutations. The potential of these two methods can be enhanced by the combination with fluorescence in situ hybridization (FISH techniques. FISH plus comet assay allows the recognition of targets of DNA damage and repairing directly. FISH combined with MN test is able to characterize the occurrence of different chromosomes in MN and to identify potential chromosomal targets of mutagenic substances. Thus, combination of FISH with the comet assay or MN test proved to be promising techniques for evaluation of the distribution of DNA and chromosome damage in the entire genome of individual cells. FISH technique also permits to study comet and MN formation, necessary for correct application of these methods. This paper reviews the relevant literature on advantages and limitations of Comet-FISH and MN-FISH assays application in genetic toxicology.

Assessment of Pharmacogenomic Panel Assay for Prediction of Taxane Toxicities: Preliminary Results

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Raffaele Di Francia

2017-11-01

Full Text Available Backbone: Paclitaxel and docetaxel are the primary taxane anticancer drugs regularly used to treat, breast, gastric, ovarian, head/neck, lung, and genitourinary neoplasm. Suspension of taxane treatments compromising patient benefits is more frequently caused by peripheral neuropathy and allergy, than to tumor progression. Several strategies for preventing toxicity have been investigated so far. Recently, findings on the genetic variants associated with toxicity and resistance to taxane-based chemotherapy have been reported.Methods: An extensive panel of five polymorphisms on four candidate genes (ABCB1, CYP2C8*3, CYP3A4*1B, XRCC3, previously validated as significant markers related to paclitaxel and Docetaxel toxicity, are analyzed and discussed. We genotyped 76 cancer patients, and 35 of them received paclitaxel or docetaxel-based therapy. What is more, an early outline evaluation of the genotyping costs and benefit was assessed.Results: Out of 35 patients treated with a taxane, six (17.1% had adverse neuropathy events. Pharmacogenomics analysis showed no correlation between candidate gene polymorphisms and toxicity, except for the XRCC3 AG+GG allele [OR 2.61 (95% CI: 0.91–7.61] which showed a weak significant trend of risk of neurotoxicities vs. the AG allele [OR 1.52 (95% CI: 0.51–4.91] P = 0.03.Summary: Based on our experimental results and data from the literature, we propose a useful and low-cost genotyping panel assay for the prevention of toxicity in patients undergoing taxane-based therapy. With the individual pharmacogenomics profile, clinicians will have additional information to plan the better treatment for their patients to minimize toxicity and maximize benefits, including determining cost-effectiveness for national healthcare sustainability.

Human Pluripotent Stem Cell-Based Assay Predicts Developmental Toxicity Potential of ToxCast Chemicals (ACT meeting)

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Worldwide initiatives to screen for toxicity potential among the thousands of chemicals currently in use require inexpensive and high-throughput in vitro models to meet their goals. The devTOX quickPredict platform is an in vitro human pluripotent stem cell-based assay used to as...

Toxicity assessment of silica coated iron oxide nanoparticles and biocompatibility improvement by surface engineering.

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Maria Ada Malvindi

Full Text Available We have studied in vitro toxicity of iron oxide nanoparticles (NPs coated with a thin silica shell (Fe3O4/SiO2 NPs on A549 and HeLa cells. We compared bare and surface passivated Fe3O4/SiO2 NPs to evaluate the effects of the coating on the particle stability and toxicity. NPs cytotoxicity was investigated by cell viability, membrane integrity, mitochondrial membrane potential (MMP, reactive oxygen species (ROS assays, and their genotoxicity by comet assay. Our results show that NPs surface passivation reduces the oxidative stress and alteration of iron homeostasis and, consequently, the overall toxicity, despite bare and passivated NPs show similar cell internalization efficiency. We found that the higher toxicity of bare NPs is due to their stronger in-situ degradation, with larger intracellular release of iron ions, as compared to surface passivated NPs. Our results indicate that surface engineering of Fe3O4/SiO2 NPs plays a key role in improving particles stability in biological environments reducing both cytotoxic and genotoxic effects.

Development of a male reproductive toxicity assay for evaluating the success of bioremediation

International Nuclear Information System (INIS)

Schrock, E.J.; Bantle, J.A.

1995-01-01

The Eglin Air Force Base was contaminated with JP-4 over 10 years ago. The project goal was to develop and evaluate male reproductive toxicity testing procedures and endpoints using the gametes of the South African clawed frog Xenopus laevis with particular emphasis on assessing the toxicity of contaminated soil from Eglin Air Force Base in Florida. Reproductive toxicity tests were done to evaluate several different locations within the original spill area. Specific sites were selected based on their location to the spill site. The site was evaluated before and after remediation. Before remediation, the males were exposed to the JP-4 orally for 73 days, with the contaminant injected into the food source. After remediation, the males were directly exposed to the contaminated soil samples for 60 days. The endpoints measured in both studies were: change in body weight, organ to body weight ratios, sperm counts, number of malformed sperm, and sperm motility. In both the pre and post remediation studies, there were no significant effects on body weight or organ weight data at the p ≤ 0.05 level. However, there were effects seen in sperm count and morphology. The male reproductive toxicity assay under development has given useful information in initially determining the reproductive toxicity of JP-4. Significant effects were seen in both the pre and post remediation direct exposure tests, indicating that the direct exposure route may be the most promising for future testing

In situ modification of activated carbons developed from a native invasive wood on removal of trace toxic metals from wastewater.

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de Celis, J; Amadeo, N E; Cukierman, A L

2009-01-15

Activated carbons were developed by phosphoric acid activation of sawdust from Prosopis ruscifolia wood, an indigenous invasive species of degraded lands, at moderate conditions (acid/precursor ratio=2, 450 degrees C, 0.5h). For in situ modification of their characteristics, either a self-generated atmosphere or flowing air was used. The activated carbons developed in the self-generated atmosphere showed higher BET surface area (2281m2/g) and total pore volume (1.7cm3/g) than those obtained under flowing air (1638m2/g and 1.3cm3/g). Conversely, the latter possessed a higher total amount of surface acidic/polar oxygen groups (2.2meq/g) than the former (1.5meq/g). To evaluate their metal sorption capability, adsorption isotherms of Cu(II) ion from model solutions were determined and properly described by the Langmuir model. Maximum sorption capacity (Xm) for the air-derived carbons (Xm=0.44mmol/g) almost duplicated the value for those obtained in the self-generated atmosphere (Xm=0.24mmol/g), pointing to a predominant effect of the surface functionalities on metal sequestering behaviour. The air-derived carbons also demonstrated a superior effectiveness in removing Cd(II) ions as determined from additional assays in equilibrium conditions. Accordingly, effective phosphoric acid-activated carbons from Prosopis wood for toxic metals removal from wastewater may be developed by in situ modification of their characteristics operating under flowing air.

A flow-cytometric NK-cytotoxicity assay adapted for use in rat repeated dose toxicity studies

International Nuclear Information System (INIS)

Marcusson-Staahl, Maritha; Cederbrant, Karin

2003-01-01

A recent regulatory document for immunotoxicity testing of new pharmaceutical drugs includes cytotoxic natural killer (NK)-cell function as a required parameter in repeated dose toxicity studies. The classical 51 Cr-release assay is the conventional test for cytotoxicity testing but several drawbacks with this assay has increased the demand for new reliable test systems. Here, we describe the optimisation of a flow-cytometric cytotoxicity assay especially adapted for regulatory rat studies in drug development. The test principle is based on target cell labelling with 5-(6)-carboxy-fluorescein succinimidyl ester (CFSE) and subsequent DNA-labelling with propidium iodide (PI) for identification of target cells with compromised cell membranes. The results are expressed as percentage of dead targets on a cell-to-cell basis. The final format of the assay includes 0.5 ml peripheral blood, 1.25x10 5 effector cells per sample, and collection of 500 target events by flow-cytometry. When NKR-P1+ cells were removed from the effector cell population by magnetic depletion the relative proportion decreased from 6 to 0.08%. The corresponding cytotoxic activity decreased from 68 to 8%. Also, the cytotoxic activity showed a significant and positive correlation with the proportion of NK-cells present in the effector cell suspension. Thus, the cytotoxicity measured is almost exclusively exerted by NK-cells. The current flow-cytometric test benefits from using peripheral blood as a source for effector cells since it will not conflict with the use of spleen for histopathological investigations in repeated dose toxicity studies. Additionally, since only a minimal number of effector cells are required per sample repeated testing of the same animal is enabled

First results with a radioreceptor-assay (TRAK-Assay) for TSH-receptor-autoantibodies

International Nuclear Information System (INIS)

Becker, W.; Reiners, C.; Boerner, W.

1983-01-01

A new radioreceptor-assay (TRAK-assay) for autoantibodies against TSH-receptors was tested in 48 untreated thyrotoxic patients (26 regional autonomies, 22 toxic diffuse goiters). None of the 26 patients with regional autonomy showed positive autoantibody-titers. 4 patients with toxic diffuse goiter and thyrotoxic exophthalmos were TRAK-positive. Positive titers of microsomal and thyreoglobulin autoantibodies could be seen in 8 of 9 patients with positive TRAK-titers. In accordance with the conventional methods for detecting thyroid-stimulating immunoglobulins the new TRAK-assay seems to be suited for differentiating between immunogenic toxic diffuse goiter (Graves' disease) and goiter with disseminated autonomy as well as for prediction of relapse. (orig.) [de

Unique Nanoparticle Optical Properties Confound Fluorescent Based Assays Widely Employed in Their In Vitro Toxicity Screening and Ranking

Science.gov (United States)

Nanoparticles (NPs) are novel materials having at least one dimension less than 100 nm and display unique physicochemical properties due to their nanoscale size. An emphasis has been placed on developing high throughput screening (HTS) assays to characterize and rank the toxiciti...

Toxicity evaluation of ZnO nanostructures on L929 fibroblast cell line using MTS assay

Energy Technology Data Exchange (ETDEWEB)

Bakhori, Siti Khadijah Mohd; Mahmud, Shahrom; Ann, Ling Chuo [Nano-optoelectronics Research and Technology Laboratory (NOR.), School of Physics, Universiti Sains Malaysia, 11800, USM, Pulau Pinang (Malaysia); Mohamed, Azman Seeni; Saifuddin, Siti Nazmin [Integrative Medicine Cluster, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Bandar Putra Bertam, 13200 Kepala Batas, Pulau Pinang (Malaysia); Masudi, Sam’an Malik; Mohamad, Dasmawati [Craniofacial Science Laboratory, School of Dentistry, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan (Malaysia)

2015-04-24

ZnO has wide applications in medical and dentistry apart from being used as optoelectronic devices such as solar cells, photodetectors, sensors and light emitting diodes (LEDs). Therefore, the toxicity evaluation is important to know the toxicity level on normal cell line. The toxicity of two grades ZnO nanostructures, ZnO-4 and ZnO-8 have been carried out using cytotoxicity test of MTS assay on L929 rat fibroblast cell line. Prior to that, ZnO-4 and ZnO-8 were characterized for its morphology, structure and optical properties using FESEM, X-ray diffraction, and Photoluminescence respectively. The two groups revealed difference in morphology and exhibit slightly shifted of near band edge emission of Photoluminescence other than having a similar calculated crystallite size of nanostructures. The viability of cells after 72h were obtained and the statistical significance value was calculated using SPSS v20. The p value is more than 0.05 between untreated and treated cell with ZnO. This insignificant value of p>0.05 can be summarized as a non-toxic level of ZnO-4 and ZnO-8 on the L929 cell line.

Toxicity evaluation of ZnO nanostructures on L929 fibroblast cell line using MTS assay

International Nuclear Information System (INIS)

Bakhori, Siti Khadijah Mohd; Mahmud, Shahrom; Ann, Ling Chuo; Mohamed, Azman Seeni; Saifuddin, Siti Nazmin; Masudi, Sam’an Malik; Mohamad, Dasmawati

2015-01-01

ZnO has wide applications in medical and dentistry apart from being used as optoelectronic devices such as solar cells, photodetectors, sensors and light emitting diodes (LEDs). Therefore, the toxicity evaluation is important to know the toxicity level on normal cell line. The toxicity of two grades ZnO nanostructures, ZnO-4 and ZnO-8 have been carried out using cytotoxicity test of MTS assay on L929 rat fibroblast cell line. Prior to that, ZnO-4 and ZnO-8 were characterized for its morphology, structure and optical properties using FESEM, X-ray diffraction, and Photoluminescence respectively. The two groups revealed difference in morphology and exhibit slightly shifted of near band edge emission of Photoluminescence other than having a similar calculated crystallite size of nanostructures. The viability of cells after 72h were obtained and the statistical significance value was calculated using SPSS v20. The p value is more than 0.05 between untreated and treated cell with ZnO. This insignificant value of p>0.05 can be summarized as a non-toxic level of ZnO-4 and ZnO-8 on the L929 cell line

Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships (MCBIOS)

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Comparative Analysis of Predictive Models for Liver Toxicity Using ToxCast Assays and Quantitative Structure-Activity Relationships Jie Liu1,2, Richard Judson1, Matthew T. Martin1, Huixiao Hong3, Imran Shah1 1National Center for Computational Toxicology (NCCT), US EPA, RTP, NC...

Pulmonary toxicity of nanomaterials: a critical comparison of published in vitro assays and in vivo inhalation or instillation studies.

Science.gov (United States)

Landsiedel, Robert; Sauer, Ursula G; Ma-Hock, Lan; Schnekenburger, Jürgen; Wiemann, Martin

2014-11-01

To date, guidance on how to incorporate in vitro assays into integrated approaches for testing and assessment of nanomaterials is unavailable. In addressing this shortage, this review compares data from in vitro studies to results from in vivo inhalation or intratracheal instillation studies. Globular nanomaterials (ion-shedding silver and zinc oxide, poorly soluble titanium dioxide and cerium dioxide, and partly soluble amorphous silicon dioxide) and nanomaterials with higher aspect ratios (multiwalled carbon nanotubes) were assessed focusing on the Organisation for Economic Co-Operation and Development (OECD) reference nanomaterials for these substances. If in vitro assays are performed with dosages that reflect effective in vivo dosages, the mechanisms of nanomaterial toxicity can be assessed. In early tiers of integrated approaches for testing and assessment, knowledge on mechanisms of toxicity serves to group nanomaterials thereby reducing the need for animal testing.

Acute response of mouse kidney clonogens to fractionated irradiation in situ and then assayed in primary culture

International Nuclear Information System (INIS)

Yeemin Jen; Hendry, J.H.

1991-01-01

The radiosensitivity of mouse kidney cells after in situ single-dose, 2, 8, and 16 fraction X-irradiations was measured in primary culture using a clonogenic assay. The assay was made 12 h after single doses or 12 h after the last dose of the multifraction regimens. When analysed using the linear-quadratic model, as predicted the individual α components for all the different fractionation schedules were not significantly different, and the changes in the β values were consistent with those expected on the basis of the reciprocal fraction numbers. When all four data sets were integrated to derive a common α/β ratio, the result was 4.4±1.3 (1SE) Gy, or 2.8±0.9 Gy (a better fit) if the single-dose data set was excluded. These values fall into the range reported for kidney using assays of tissue function at long times after irradiation. (author)

Ceriodaphnia and Chironomus in situ toxicity tests assessing the wastewater treatment efficacy of constructed wetlands

International Nuclear Information System (INIS)

Barjaktarovic, L.; Nix, P.; Gulley, J.

1995-01-01

In situ toxicity tests were designed for Ceriodaphnia dubia and Chironomus tentans as part of a larger study designed to assess the effectiveness of constructed wetlands for the treatment of wastewater produced by oil production at Suncor OSG. The artificial wetlands were 50m long by 3m wide, with three replicates of the control and the treatment. Each wetland had four sample sites equidistant along its length, creating a gradient of treatment from site A being the most toxic to site D being the least toxic. Each test was conducted twice during the summer of 1994. Both the Ceriodaphnia and Chironomus test cages were a flow through design to allow for maximal exposure to the water within the wetlands. Mortality and reproduction were used as endpoints for Ceriodaphnia, whereas mortality and growth were used as endpoints for the Chironomus test. Test durations were fifteen and ten days respectively. Chironomus had very high mortality along the entire wetlands whereas Ceriodaphnia survival and fecundity increased along the length of the treatment wetlands. Both organisms had low mortality and high growth/fecundity in the control wetlands

A high-throughput method for assessing chemical toxicity using a Caenorhabditis elegans reproduction assay

International Nuclear Information System (INIS)

Boyd, Windy A.; McBride, Sandra J.; Rice, Julie R.; Snyder, Daniel W.; Freedman, Jonathan H.

2010-01-01

The National Research Council has outlined the need for non-mammalian toxicological models to test the potential health effects of a large number of chemicals while also reducing the use of traditional animal models. The nematode Caenorhabditis elegans is an attractive alternative model because of its well-characterized and evolutionarily conserved biology, low cost, and ability to be used in high-throughput screening. A high-throughput method is described for quantifying the reproductive capacity of C. elegans exposed to chemicals for 48 h from the last larval stage (L4) to adulthood using a COPAS Biosort. Initially, the effects of exposure conditions that could influence reproduction were defined. Concentrations of DMSO vehicle ≤ 1% did not affect reproduction. Previous studies indicated that C. elegans may be influenced by exposure to low pH conditions. At pHs greater than 4.5, C. elegans reproduction was not affected; however below this pH there was a significant decrease in the number of offspring. Cadmium chloride was chosen as a model toxicant to verify that automated measurements were comparable to those of traditional observational studies. EC 50 values for cadmium for automated measurements (176-192 μM) were comparable to those previously reported for a 72-h exposure using manual counting (151 μM). The toxicity of seven test toxicants on C. elegans reproduction was highly correlative with rodent lethality suggesting that this assay may be useful in predicting the potential toxicity of chemicals in other organisms.

Discovering less toxic ionic liquids by using the Microtox® toxicity test.

Science.gov (United States)

Hernández-Fernández, F J; Bayo, J; Pérez de los Ríos, A; Vicente, M A; Bernal, F J; Quesada-Medina, J

2015-06-01

New Microtox® toxicity data of 16 ionic liquids of different cationic and anionic composition were determined. The ionic liquids 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, [BMPyr(+)][TFO(-)], 1-butyl-1-methylpyrrolidinium chloride, [BMPyr(+)][Cl(-)], hydroxypropylmethylimidazolium fluoroacetate, [HOPMIM(+)][FCH2COO(-)], and hydroxypropylmethylimidazolium glycolate [HOPMIM(+)][glycolate(-)] were found to be less toxic than conventional organic solvent such as chloroform or toluene, accoding the Microtox® toxicity assays. The toxicity of pyrrolidinium cation was lower than the imidazolium and pyridinium ones. It was found that the inclusion of an hydroxyl group in the alkyl chain length of the cation also reduce the toxicity of the ionic liquid. To sum up, the Microtox® toxicity assays can be used as screening tool to easily determined the toxicity of a wide range of ionic liquids and the toxicity data obtained could allow the obtention of structure-toxicity relationships to design less toxic ionic liquids. Copyright © 2015 Elsevier Inc. All rights reserved.

A combined approach to investigate the toxicity of an industrial landfill's leachate: Chemical analyses, risk assessment and in vitro assays

International Nuclear Information System (INIS)

Baderna, D.; Maggioni, S.; Boriani, E.; Gemma, S.; Molteni, M.; Lombardo, A.; Colombo, A.; Bordonali, S.; Rotella, G.; Lodi, M.; Benfenati, E.

2011-01-01

Solid wastes constitute an important and emerging problem. Landfills are still one of the most common ways to manage waste disposal. The risk assessment of pollutants from landfills is becoming a major environmental issue in Europe, due to the large number of sites and to the importance of groundwater protection. Furthermore, there is lack of knowledge for the environmental, ecotoxicological and toxicological characteristics of most contaminants contained into landfill leacheates. Understanding leachate composition and creating an integrated strategy for risk assessment are currently needed to correctly face the landfill issues and to make projections on the long-term impacts of a landfill, with particular attention to the estimation of possible adverse effects on human health and ecosystem. In the present study, we propose an integrated strategy to evaluate the toxicity of the leachate using chemical analyses, risk assessment guidelines and in vitro assays using the hepatoma HepG2 cells as a model. The approach was applied on a real case study: an industrial waste landfill in northern Italy for which data on the presence of leachate contaminants are available from the last 11 years. Results from our ecological risk models suggest important toxic effects on freshwater fish and small rodents, mainly due to ammonia and inorganic constituents. Our results from in vitro data show an inhibition of cell proliferation by leachate at low doses and cytotoxic effect at high doses after 48 h of exposure. - Research highlights: → We study the toxicity of leachate from a non-hazardous industrial waste landfill. → We perform chemical analyses, risk assessments and in vitro assays on HepG2 cells. → Risk models suggest toxic effects due to ammonia and inorganic constituents. → In vitro assays show that leachate inhibits cell proliferation at low doses. → Leachate can induce cytotoxic effects on HepG2 cells at high doses.

Determination of leachate toxicity through acute toxicity using Daphnia pulex and anaerobic toxicity assays

OpenAIRE

Carabalí-Rivera, Y. S; Barba-Ho, L. E; Torres-Lozada, P

2017-01-01

ABSTRACT The municipal solid waste (MSW) of large cities, in particular the ones of developing countries, is mainly disposed in landfills (LFs), whose inadequate management generates the emission of greenhouse gases and the production of leachates with high concentrations of organic and inorganic matter and, occasionally heavy metals. In this study, the toxicity of the leachates from an intermediate-age municipal landfill was evaluated by ecotoxicity and anaerobic toxicity tests. The acute to...

Evaluation of an adherent mouse embryonic stem cell in vitro assay to predict developmental toxicity of ToxCast chemicals.

Science.gov (United States)

The potential for most environmental chemicals to produce developmental toxicity is unknown. Mouse embryonic stem cell (mESC) assays are an alternative in vitro model to assess chemicals. The chemical space evaluated using mESC and compared to in vivo is limited. We used an adher...

Chronic toxicity, genotoxic assay, and phytochemical analysis of four traditional medicinal plants.

Science.gov (United States)

Castañeda Sortibrán, América; Téllez, María Guadalupe Ordaz; Ocotero, Verónica Muñoz; Carballo-Ontiveros, Marco Antonio; García, Angélica Méndez; Valdés, Rocio Jimena Jiménez; Gutiérrez, Elizabeth Romero; Rodríguez-Arnaiz, Rosario

2011-09-01

Four medicinal plants--Tecoma stans, Ligusticum porteri, Monarda austromontana, and Poliomintha longiflora, which are distributed in tropical and subtropical countries of the American continent--are widely used in folk medicine to treat diseases such as diarrhea and dysentery. In addition, T. stans and P. longiflora are extensively used as hypoglycemic agents, and M. austromontana and P. longiflora are used as condiments. The plants were collected, identified, dried, and pulverized. Solvent extraction was prepared by maceration of the plant samples, and the phytochemical composition of the extracts was determined by using standard analysis procedures. Phytochemical analysis showed the presence of triterpenoids/steroids, flavonoids, and phenols/tannins and, in L. porteri, traces of alkaloids. After the elimination of solvents in vacuo, the extracts were administrated to Drosophila larvae to test their toxicity and genotoxicity. Third instar larvae were chronically fed with the phytoextracts. The extract from L. porteri was toxic, whereas those from T. stans, P. longiflora, and M. austromontana were not. Genotoxic activities of the 4 plants were investigated by using the wing-spot assay of D. melanogaster. Mitomycin C was used as a positive control. No statistically significant increase was observed between treated sample series and a concurrent negative (water) or solvent control sample series.

Assessing toxic levels of hydrocarbons on microbial degrader communities in vadose zone fill soils

International Nuclear Information System (INIS)

Schoenberg, T.H.; Long, S.C.

1995-01-01

Authentic fill samples were collected from the vadose zone at a highway travel plaza. The contamination at the site is a combination of gasoline, diesel, and waste oil resulting from leaking underground storage tanks. Microbial assessments including plate counts and specific-degrader enumerations were performed to establish the presence of degrader microbial communities, and thus bioremediation potential. Contaminant levels were estimated in samples by quantifying headspace VOCs in collection jars. Physical soil characteristics including soil grain size distribution and moisture content were measured to evaluate the potential ecological variables that would affect implementation of a bioremediation technology. Toxicity screening using the Microtox trademark acute toxicity assay was used to compare the level of toxicity present among samples. These analyses were used to assess the potential for using in situ bioventing remediation to clean-up the leaking underground storage tank spill study site. High contaminant levels appear to have exerted a toxic effect and resulted in smaller total microbial community sizes in highly contaminated areas (thousands of ppmv) of the site. Microtox trademark EC50 results generally corroborated with the trends of the enumeration experiments. Microbial characterization results indicate that in situ bioremediation would be possible at the study site. Soil heterogeneity appears to pose the greatest challenges to the design and implementation of bioremediation at this site

Acute toxicity evaluation of in situ gel-forming controlled drug delivery system based on biodegradable poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) copolymer

International Nuclear Information System (INIS)

Fang Fang; Gong Changyang; Dong Pengwei; Fu Shaozhi; Gu Yingchun; Guo Gang; Zhao Xia; Wei Yuquan; Qian Zhiyong

2009-01-01

In this paper, biodegradable poly(ε-caprolactone)-poly(ethylene glycol)-poly(ε-caprolactone) (PCL-PEG-PCL) triblock copolymer was synthesized, and was characterized by FTIR, 1 H-NMR and GPC. The PCL-PEG-PCL/dimethyl sulfoxide (DMSO) solution displayed in situ gelling behavior when subcutaneously injected into the body. Toxicity tests and a histopathological study were performed in BALB/c mice. We focused mainly on acute organ toxicity of BALB/c mice by subcutaneous injection. In the acute toxicity test, the dose of subcutaneous injection was 5 g/kg body weight (b.w.), and the mice were observed continuously for 14 days. For the histopathological study, samples including heart, lung, liver, kidneys, spleen, stomach and intestine were histochemically prepared and stained with hematoxylin-eosin for histopathological examination. No mortality or significant signs of toxicity were observed during the whole observation period, and there is no significant lesion to be shown in histopathological study of major organs in the mice. Therefore, the maximal tolerance dose of dimethyl sulfoxide (DMSO) solution of PCL-PEG-PCL copolymer by subcutaneous injection was calculated to be higher than 5 g/kg b.w. Therefore, the PCL-PEG-PCL/DMSO system was thought to be non-toxic after subcutaneous injection, and it might be a candidate for an in situ gelling controlled drug delivery system.

Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

Directory of Open Access Journals (Sweden)

G. Persoone

2009-08-01

Full Text Available One of the most internationally used bioassays for toxicity screening of chemicals and for toxicity monitoring of effluents and contaminated waters is the acute toxicity test with daphnid crustaceans, and in particular that performed with Daphnia magna.Standard methods have been developed for this assay that were gradually endorsed by national and international organisations dealing with toxicity testing procedures, in view of its application within a regulatory framework. As for all toxicity tests, the organisms used for the acute D. magna assay have to be obtained from live stocks which are cultured in the laboratory on live food (micro-algae.Unsurprisingly the various standard protocols of this particular assay differ – at least to a certain extent – with regard to the test organism culturing conditions. In addition, some technical aspects of the toxicity test such as the effect criterion (mortality of immobility, the exposure time, the type of dilution water, etc., also vary from one standard to another.Although this particular assay is currently used in many countries, the technical and biological problems inherent in year-round culturing and availability of the biological material and the culturing/maintenance costs of live stocks restrict its application to a limited number of highly specialised laboratories.This fundamental bottleneck in toxicity testing triggered investigations which brought forward the concept of “microbiotests” or “small-scale” toxicity tests. “Culture/maintenance free” aquatic microbiotests with species of different phylogenetic groups were developed in the early 1990s at the Laboratory for Environmental Toxicology and Aquatic Ecology at the Ghent University in Belgium.These assays which were given the generic name “Toxkits”, are unique in that they employ dormant stages (“cryptobiotic eggs” of the test species, which can be stored for long periods of time and “hatched” at the time of

Chromogenic in situ hybridization is a reliable assay for detection of ALK rearrangements in adenocarcinomas of the lung.

Science.gov (United States)

Schildhaus, Hans-Ulrich; Deml, Karl-Friedrich; Schmitz, Katja; Meiboom, Maren; Binot, Elke; Hauke, Sven; Merkelbach-Bruse, Sabine; Büttner, Reinhard

2013-11-01

Reliable detection of anaplastic lymphoma kinase (ALK) rearrangements is a prerequisite for personalized treatment of lung cancer patients, as ALK rearrangements represent a predictive biomarker for the therapy with specific tyrosine kinase inhibitors. Currently, fluorescent in situ hybridization (FISH) is considered to be the standard method for assessing formalin-fixed and paraffin-embedded tissue for ALK inversions and translocations. However, FISH requires a specialized equipment, the signals fade rapidly and it is difficult to detect overall morphology and tumor heterogeneity. Chromogenic in situ hybridization (CISH) has been successfully introduced as an alternative test for the detection of several genetic aberrations. This study validates a newly developed ALK CISH assay by comparing FISH and CISH signal patterns in lung cancer samples with and without ALK rearrangements. One hundred adenocarcinomas of the lung were included in this study, among them 17 with known ALK rearrangement. FISH and CISH were carried out and evaluated according to the manufacturers' recommendations. For both assays, tumors were considered positive if ≥15% of tumor cells showed either isolated 3' signals or break-apart patterns or a combination of both. A subset of tumors was exemplarily examined by using a novel EML4 (echinoderm microtubule-associated protein-like 4) CISH probe. Red, green and fusion CISH signals were clearcut and different signal patterns were easily recognized. The percentage of aberrant tumor cells was statistically highly correlated (PCISH. On the basis of 86 samples that were evaluable by ALK CISH, we found a 100% sensitivity and 100% specificity of this assay. Furthermore, EML4 rearrangements could be recognized by CISH. CISH is a highly reliable, sensitive and specific method for the detection of ALK gene rearrangements in pulmonary adenocarcinomas. Our results suggest that CISH might serve as a suitable alternative to FISH, which is the current gold

Metabolic profiles show specific mitochondrial toxicities in vitro in myotube cells

International Nuclear Information System (INIS)

Xu Qiuwei; Vu, Heather; Liu Liping; Wang, Ting-Chuan; Schaefer, William H.

2011-01-01

Mitochondrial toxicity has been a serious concern, not only in preclinical drug development but also in clinical trials. In mitochondria, there are several distinct metabolic processes including fatty acid β-oxidation, the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation (OXPHOS), and each process contains discrete but often intimately linked steps. Interruption in any one of those steps can cause mitochondrial dysfunction. Detection of inhibition to OXPHOS can be complicated in vivo because intermediate endogenous metabolites can be recycled in situ or circulated systemically for metabolism in other organs or tissues. Commonly used assays for evaluating mitochondrial function are often applied to ex vivo or in vitro samples; they include various enzymatic or protein assays, as well as functional assays such as measurement of oxygen consumption rate, membrane potential, or acidification rates. Metabolomics provides quantitative profiles of overall metabolic changes that can aid in the unraveling of explicit biochemical details of mitochondrial inhibition while providing a holistic view and heuristic understanding of cellular bioenergetics. In this paper, we showed the application of quantitative NMR metabolomics to in vitro myotube cells treated with mitochondrial toxicants, rotenone and antimycin A. The close coupling of the TCA cycle to the electron transfer chain (ETC) in OXPHOS enables specific diagnoses of inhibition to ETC complexes by discrete biochemical changes in the TCA cycle.

Petroleum hydrocarbon toxicity to corals: A review.

Science.gov (United States)

Turner, Nicholas R; Renegar, D Abigail

2017-06-30

The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodology, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities between studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. Following standardized protocols and quantifying the concentration and composition of toxicant will aid in comparison of results between studies and extrapolation to actual spills. Copyright © 2017 Elsevier Ltd. All rights reserved.

Relationship between lung colony and in situ assays

International Nuclear Information System (INIS)

Ando, K.; Koike, S.

1985-01-01

The relationship between different assays: tumor control, tumor growth delay and lung colony formation was examined after fast neutron and γ ray irradiations. Fibrosarcomas (NFSa) in syngeneic C3Hf mice were irradiated locally with 60 Co γ rays, fast neutrons or mixed beams (γ rays and fast neutrons). A comparison between the lung colony assay and the TRT 50 (50% tumor growth delay time) assay when cells were exposed to single doses of fast neutrons or γ rays, resulted in identical growth delay times. The fraction of cells surviving a single dose of fast neutrons, was 10 times higher than the surviving fraction of cells after a single dose of γ rays. Both doses resulted in the same tumor control probability (TCD 50 assay). Neither repair of potentially lethal damage nor tumor bed effect was sufficient to explain the difference between cell survival and tumor control probability. The surviving fraction of cells following fractionated irradiations of γ rays and fast neutrons were identical at 50% tumor control probabilities

Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S., E-mail: frank.abbott@ubc.ca

2012-11-01

Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it

Assessing off-site impacts of wildfires on aquatic organisms using in-situ assays

Science.gov (United States)

Ré, Ana; Saraiva, MariaJoão; Puga, João; Campos, Isabel; Pereira, Joana; Keizer, Jacob; Goncalves, Fernando; Abrantes, Nelson

2017-04-01

Wildfires have been recognized as an important source of diffuse pollution to aquatic systems, particularly through the production and transport of pyrolytic substances such as polycyclic aromatic hydrocarbons (PAHs) and metals associated to ash/soil loads. However, the effects of these compounds from recently burnt areas on the aquatic biota have been largely ignored. Hence, the main goal of this study was to assess the ecotoxicological effects of wildfires in aquatic systems through the use of in situ experiments. In this sense, five sites were selected in a catchment partially burnt: two in the main water course - Ceira river (Miranda do Corvo, Portugal), being one located upstream (RUS) and the other downstream (RDS) the burnt area; two in tributary streams within the burnt area (SUS and SDS); and finally one in a stream located in the unburnt part of the catchment (CS). During the first post-fire rainfall events, distinct organisms, including the water flea Daphnia magna, the freshwater shrimp Atyaephyra desmaresti, the freshwater clam Corbicula fluminea and the mosquitofish Gambusia holbrooki were exposed in situ, in all five sites, using dedicated test chambers. After four days of field exposition, the mortality and post-exposure feeding inhibition were evaluated. Feeding depression after exposure time was selected as a sub-lethal endpoint because it is a quick, sensitive and ecologically relevant indicator of toxic stress. The results showed negligible mortality for all the species and sites, thus lethality was not sensitive to discern impacts among the assessed sites. Conversely, the sub-lethal post-exposure feeding inhibition endpoint, revealed a decrease of feeding rate, in streams within the burnt area (SUS and SDS), that seemed to be the most affected places in the study area. Conversely, the sites outside the burnt area, both on river (RUS) and on the stream (CS), showed no adverse effects in this endpoint. Hence, the current results pointed-out that

Introducing Environmental Toxicology in Instructional Labs: The Use of a Modified Amphibian Developmental Toxicity Assay to Support Inquiry-Based Student Projects

Science.gov (United States)

Sauterer, Roger; Rayburn, James R.

2012-01-01

Introducing students to the process of scientific inquiry is a major goal of high school and college labs. Environmental toxins are of great concern and public interest. Modifications of a vertebrate developmental toxicity assay using the frog Xenopus laevis can support student-initiated toxicology experiments that are relevant to humans. Teams of…

Toxicities of emamectin benzoate homologues and photodegradates to Lepidoptera.

Science.gov (United States)

Argentine, Joseph A; Jansson, Richard K; Starner, Van R; Halliday, W Ross

2002-12-01

The toxicity of a number of emamectin benzoate homologues and photodegradates to five species of Lepidoptera was investigated using diet and foliar bioassays. The emamectin benzoate homologues B1a and B1b were equally toxic in the diet and foliar assays to Spodoptera exigua (Hübner), Heliothis virescens (F.), Tricoplusia ni (Hübner), and Spodoptera frugiperda (J. E. Smith), within each of these species. Plutella xylostella (L.) was the most sensitive species to emamectin benzoate. The AB1a photodegradate of emamectin benzoate was as toxic as the parent compound in the diet assay. However, in the foliage assay AB1a was 4.4-fold less toxic to S. exigua than the parent compound. The MFB1a photodegradate of emamectin benzoate was as toxic as the parent compound to P. xylostella, and 3.1 to 6.2 times as toxic as the parent compound to the other species in the diet assay. The order of toxicity of the photodegradates were AB1a > MFB1a > FAB1a > 8,9-Z-MAB1a > PAB1a.

High-throughput respirometric assay identifies predictive toxicophore of mitochondrial injury

Energy Technology Data Exchange (ETDEWEB)

Wills, Lauren P. [MitoHealth Inc., Charleston, SC 29403 (United States); Beeson, Gyda C.; Trager, Richard E.; Lindsey, Christopher C. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Beeson, Craig C. [MitoHealth Inc., Charleston, SC 29403 (United States); Peterson, Yuri K. [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Schnellmann, Rick G., E-mail: schnell@musc.edu [Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425 (United States); Ralph H. Johnson VA Medical Center, Charleston, SC 29401 (United States)

2013-10-15

Many environmental chemicals and drugs negatively affect human health through deleterious effects on mitochondrial function. Currently there is no chemical library of mitochondrial toxicants, and no reliable methods for predicting mitochondrial toxicity. We hypothesized that discrete toxicophores defined by distinct chemical entities can identify previously unidentified mitochondrial toxicants. We used a respirometric assay to screen 1760 compounds (5 μM) from the LOPAC and ChemBridge DIVERSet libraries. Thirty-one of the assayed compounds decreased uncoupled respiration, a stress test for mitochondrial dysfunction, prior to a decrease in cell viability and reduced the oxygen consumption rate in isolated mitochondria. The mitochondrial toxicants were grouped by chemical similarity and two clusters containing four compounds each were identified. Cheminformatic analysis of one of the clusters identified previously uncharacterized mitochondrial toxicants from the ChemBridge DIVERSet. This approach will enable the identification of mitochondrial toxicants and advance the prediction of mitochondrial toxicity for both drug discovery and risk assessment. - Highlights: • Respirometric assay conducted in RPTC to create mitochondrial toxicant database. • Chemically similar mitochondrial toxicants aligned as mitochondrial toxicophores • Mitochondrial toxicophore identifies five novel mitochondrial toxicants.

High-throughput respirometric assay identifies predictive toxicophore of mitochondrial injury

International Nuclear Information System (INIS)

Wills, Lauren P.; Beeson, Gyda C.; Trager, Richard E.; Lindsey, Christopher C.; Beeson, Craig C.; Peterson, Yuri K.; Schnellmann, Rick G.

2013-01-01

Many environmental chemicals and drugs negatively affect human health through deleterious effects on mitochondrial function. Currently there is no chemical library of mitochondrial toxicants, and no reliable methods for predicting mitochondrial toxicity. We hypothesized that discrete toxicophores defined by distinct chemical entities can identify previously unidentified mitochondrial toxicants. We used a respirometric assay to screen 1760 compounds (5 μM) from the LOPAC and ChemBridge DIVERSet libraries. Thirty-one of the assayed compounds decreased uncoupled respiration, a stress test for mitochondrial dysfunction, prior to a decrease in cell viability and reduced the oxygen consumption rate in isolated mitochondria. The mitochondrial toxicants were grouped by chemical similarity and two clusters containing four compounds each were identified. Cheminformatic analysis of one of the clusters identified previously uncharacterized mitochondrial toxicants from the ChemBridge DIVERSet. This approach will enable the identification of mitochondrial toxicants and advance the prediction of mitochondrial toxicity for both drug discovery and risk assessment. - Highlights: • Respirometric assay conducted in RPTC to create mitochondrial toxicant database. • Chemically similar mitochondrial toxicants aligned as mitochondrial toxicophores • Mitochondrial toxicophore identifies five novel mitochondrial toxicants

Development of a heavy metals enzymatic-based assay using papain

International Nuclear Information System (INIS)

Shukor, Yunus; Baharom, Nor Azlan; Rahman, Fadhil Abd.; Abdullah, Mohd. Puad; Shamaan, Nor Aripin; Syed, Mohd. Arif

2006-01-01

A heavy metals enzymatic-based assay using papain was developed. Papain was assayed using the Casein-coomassie-dye-binding assay. The assay is sensitive to several heavy metals. The IC 50 (concentration of toxicant giving 50% inhibition) of Hg 2+ , Ag 2+ , Pb 2 , Zn 2+ is 0.39, 0.40, 2.16, 2.11 mg l -1 , respectively. For Cu 2+ and Cd 2+ the LOQ (limits of quantitation) is 0.004 and 0.1 mg l -1 , respectively. The IC 50 and LOQ values were found to be generally comparable to several other enzymatic and bioassays tests such as: immobilized urease, 15-min Microtox TM , 48 h Daphnia magna, and 96 h Rainbow trout. The papain assay is xenobiotics tolerant, has a wide pH for optimum activity, is temperature stable, and has a relatively quick assay time. The papain assay was used to identify polluted water samples from industrial sources in Penang, Malaysia. We found one site where the assay gave a positive toxic response. The toxicity of the site was confirmed using Atomic Emission Spectrometry analysis

Recovery of anaerobic digestion after exposure to toxicants. Final report

Energy Technology Data Exchange (ETDEWEB)

Yang, J.; Parkin, G.F.; Speece, R.E.

1979-12-01

The concept that methane fermentation cannot tolerate chronic or slug doses of toxicants has almost totally precluded methane fermentation as a viable contender for the treatment of industrial wastewaters. This study assayed a wide variety of toxicants, heavy metals, inorganic salts, organic chemicals, solvents, and antibiotics which are used in industrial processes and, therefore, appear in the industrial wastewaters therefrom. Toxicity was related to the reduction in methane production of a control containing no toxicant. The response of methane fermentation after exposure to a toxicant was assayed with unacclimated cultures as well as cultures which had been acclimated to increasing concentrations of the toxicant over long periods of time. The reversible nature of the toxicants was assayed by adding slug doses to plug flow anaerobic filters and recording gas production prior to, during, and after toxicant addition.

Isonychia spp. and macroinvertebrate community responses to stressors in streams utilizing the benthic in situ toxicity identification evaluation (BiTIE) method

International Nuclear Information System (INIS)

Custer, Kevin W.; Burton, G. Allen

2008-01-01

Exposures of caged organisms in situ have proven to be a useful way to improve exposure realism and link to stressor effects in aquatic assessments of hazard or risk. A novel cage system, the benthic in situ toxicity identification evaluation (BiTIE), was developed for benthic macroinvertebrates (surrogate species, resident populations and communities) to separate low and high flow effects, and major chemical classes of stressors in streams. Three resin types were used to separate the chemical stressors in the streams Honey Creek and Little Beavercreek, Ohio, USA: Dowex TM Optipore TM (non-polar organics), zeolite (ammonia), and polywool (control). Isonychia spp. sensitivity was compared to Chironomus tentans, and no significant differences were found (p > 0.05). Isonychia spp. growth (length) showed a stressor response in the zeolite treatments, and community testing revealed improved metric responses in the Dowex TM treatments. The BiTIE chamber system demonstrated stressor-response relationships using sublethal and multimetric endpoints. - Use of an indigenous aquatic insect and benthic macroinvertebrate communities allows for discerning the stressors in low and high flows with an in situ TIE approach

Biological control of toxic cyanobacteri

CSIR Research Space (South Africa)

Ndlela, Luyanda L

2017-05-01

Full Text Available . Ecotoxicity studies: is toxicity reduced? (Testing on daphnids, fish and human cell lines) Resulting impacts on cyanotoxins (Toxin conformation changes, ELISA detection) Competition assays against toxic cyanobacteria (Can Bacillus etc. outcompete...

Application of in-situ bioassays with macrophytes in aquatic mesocosm studies.

Science.gov (United States)

Coors, Anja; Kuckelkorn, Jochen; Hammers-Wirtz, Monika; Strauss, Tido

2006-10-01

Aquatic mesocosm studies assess ecotoxicological effects of chemicals by using small artificial ponds as models of lentic ecosystems. In this study, methods of controlled insertion of macrophytes within an outdoor mesocosm study were explored. Although analytically confirmed concentrations of the model herbicide terbuthylazine were high enough to expect direct effects on phytoplankton, functional parameters and dominant taxa abundance indicated only minor and transient effects. In-situ assays with Lemna minor, Myriophyllum spicatum, Potamogeton lucens and Chara globularis revealed adverse effects at concentrations in accordance with literature data. Complex interactions such as nutrient limitation and competition were possible reasons for the observed growth promotion at the lower concentration of about 5 microg/l terbuthylazine. The approach of macrophyte in-situ bioassays within a mesocosm study proved to be applicable. Presumed advantages are simultaneous acquisition of toxicity data for several species of aquatic plants under more realistic conditions compared to laboratory tests and inclusion of macrophytes as important structural and functional components in mesocosms while limiting their domination of the model ecosystem.

Determination of toxicity assays, trophic state index, and physicochemical parameters on Piracicaba River and Itapeva Stream

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Larissa de Assunção Rodrigues

2015-04-01

Full Text Available Anthropogenic activity has a great impact on aquatic environments, causing changes in biodiversity and the environment. In an attempt to determine pollution levels, we established physicochemical parameters, a trophic state index and toxicity assays. The Piracicaba River is an important water body that receives xenobiotic waste from industry, domestic activities and agriculture. These pollutants are released directly into the river or by streams like Itapeva Stream, which discharges into the river. The goals of this work were to analyze the toxicity factor for Daphnia magna (TFD, trophic state index (TSI, pH, conductivity, temperature and dissolved oxygen in the Piracicaba River and in the Itapeva Stream from one monthly collection in the months of May, June and August 2011. In the Piracicaba River was not found toxicity, while in May, June and August the TFD was 1, 8 and 1, respectively. The TSI varied from mesotrophic to eutrophic in the river and in the stream from ultraoligotrophic to mesotrophic. The medium of conductivity for the Itapeva Stream was 479.5 µS.cm-1 and for the Piracicaba River was 219.8 µS.cm-1. The dissolved oxygen in the Piracicaba River varied from 6.89 to11.36 mg.L-1 and in the Itapeva Stream from 0.92 to 6.31 mg.L-1. Based upon the results, both hydric bodies were eutrophic, and the Itapeva Stream was classified as unsuitable for maintaining aquatic life.

Isonychia spp. and macroinvertebrate community responses to stressors in streams utilizing the benthic in situ toxicity identification evaluation (BiTIE) method

Energy Technology Data Exchange (ETDEWEB)

Custer, Kevin W. [Department of Earth and Environmental Sciences, Wright State University, 127 Allyn Hall, 3640 Colonel Glenn Highway, Dayton, OH 45435 (United States)], E-mail: custer.4@wright.edu; Burton, G. Allen [Department of Earth and Environmental Sciences, Wright State University, 127 Allyn Hall, 3640 Colonel Glenn Highway, Dayton, OH 45435 (United States)

2008-01-15

Exposures of caged organisms in situ have proven to be a useful way to improve exposure realism and link to stressor effects in aquatic assessments of hazard or risk. A novel cage system, the benthic in situ toxicity identification evaluation (BiTIE), was developed for benthic macroinvertebrates (surrogate species, resident populations and communities) to separate low and high flow effects, and major chemical classes of stressors in streams. Three resin types were used to separate the chemical stressors in the streams Honey Creek and Little Beavercreek, Ohio, USA: Dowex{sup TM} Optipore{sup TM} (non-polar organics), zeolite (ammonia), and polywool (control). Isonychia spp. sensitivity was compared to Chironomus tentans, and no significant differences were found (p > 0.05). Isonychia spp. growth (length) showed a stressor response in the zeolite treatments, and community testing revealed improved metric responses in the Dowex{sup TM} treatments. The BiTIE chamber system demonstrated stressor-response relationships using sublethal and multimetric endpoints. - Use of an indigenous aquatic insect and benthic macroinvertebrate communities allows for discerning the stressors in low and high flows with an in situ TIE approach.

Cyclophosphamide-induced pulmonary toxicity

International Nuclear Information System (INIS)

Siemann, D.W.; Macler, L.; Penney, D.P.

1986-01-01

Unlike radiation effects, pulmonary toxicity following drug treatments may develop soon after exposure. The dose-response relationship between Cyclophosphamide and lung toxicity was investigated using increased breathing frequency assays used successfully for radiation induced injury. The data indicate that release of protein into the alveolus may play a significant role in Cy induced pulmonary toxicity. Although the mechanism responsible for the increased alveolar protein is as yet not identified, the present findings suggest that therapeutic intervention to inhibit protein release may be an approach to protect the lungs from toxic effects. (UK)

Evaluation of different toxicity assays applied to proliferating cells and to stratified epithelium in relation to permeability enhancement with glycocholate

DEFF Research Database (Denmark)

Eirheim, Heidi Ugelstad; Bundgaard, Christoffer; Nielsen, Hanne Mørck

2004-01-01

The purpose of the present study was to evaluate different toxicity assays for use on proliferating buccal TR146 cells and on stratified TR146 epithelium and to compare these results to the permeability enhancing effect of glycocholate (GC). Both the proliferating cells and the epithelium were...... across the epithelium concurrent with a decrease in the transepithelial electrical resistance (TEER) was also determined. The robustness of the epithelium was significantly higher than that of the proliferating cells (P...

Widespread nanoparticle-assay interference: implications for nanotoxicity testing.

Science.gov (United States)

Ong, Kimberly J; MacCormack, Tyson J; Clark, Rhett J; Ede, James D; Ortega, Van A; Felix, Lindsey C; Dang, Michael K M; Ma, Guibin; Fenniri, Hicham; Veinot, Jonathan G C; Goss, Greg G

2014-01-01

The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1) nanoparticle intrinsic fluorescence/absorbance, 2) interactions between nanoparticles and assay components, and 3) the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments.

Widespread nanoparticle-assay interference: implications for nanotoxicity testing.

Directory of Open Access Journals (Sweden)

Kimberly J Ong

Full Text Available The evaluation of engineered nanomaterial safety has been hindered by conflicting reports demonstrating differential degrees of toxicity with the same nanoparticles. The unique properties of these materials increase the likelihood that they will interfere with analytical techniques, which may contribute to this phenomenon. We tested the potential for: 1 nanoparticle intrinsic fluorescence/absorbance, 2 interactions between nanoparticles and assay components, and 3 the effects of adding both nanoparticles and analytes to an assay, to interfere with the accurate assessment of toxicity. Silicon, cadmium selenide, titanium dioxide, and helical rosette nanotubes each affected at least one of the six assays tested, resulting in either substantial over- or under-estimations of toxicity. Simulation of realistic assay conditions revealed that interference could not be predicted solely by interactions between nanoparticles and assay components. Moreover, the nature and degree of interference cannot be predicted solely based on our current understanding of nanomaterial behaviour. A literature survey indicated that ca. 95% of papers from 2010 using biochemical techniques to assess nanotoxicity did not account for potential interference of nanoparticles, and this number had not substantially improved in 2012. We provide guidance on avoiding and/or controlling for such interference to improve the accuracy of nanotoxicity assessments.

Understanding mechanisms of toxicity: Insights from drug discovery research

International Nuclear Information System (INIS)

Houck, Keith A.; Kavlock, Robert J.

2008-01-01

Toxicology continues to rely heavily on use of animal testing for prediction of potential for toxicity in humans. Where mechanisms of toxicity have been elucidated, for example endocrine disruption by xenoestrogens binding to the estrogen receptor, in vitro assays have been developed as surrogate assays for toxicity prediction. This mechanistic information can be combined with other data such as exposure levels to inform a risk assessment for the chemical. However, there remains a paucity of such mechanistic assays due at least in part to lack of methods to determine specific mechanisms of toxicity for many toxicants. A means to address this deficiency lies in utilization of a vast repertoire of tools developed by the drug discovery industry for interrogating the bioactivity of chemicals. This review describes the application of high-throughput screening assays as experimental tools for profiling chemicals for potential for toxicity and understanding underlying mechanisms. The accessibility of broad panels of assays covering an array of protein families permits evaluation of chemicals for their ability to directly modulate many potential targets of toxicity. In addition, advances in cell-based screening have yielded tools capable of reporting the effects of chemicals on numerous critical cell signaling pathways and cell health parameters. Novel, more complex cellular systems are being used to model mammalian tissues and the consequences of compound treatment. Finally, high-throughput technology is being applied to model organism screens to understand mechanisms of toxicity. However, a number of formidable challenges to these methods remain to be overcome before they are widely applicable. Integration of successful approaches will contribute towards building a systems approach to toxicology that will provide mechanistic understanding of the effects of chemicals on biological systems and aid in rationale risk assessments

Toxicity Assessment of Atrazine and Related Triazine Compounds in the Microtox Assay, and Computational Modeling for Their Structure-Activity Relationship

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Jerzy Leszczynski

2000-10-01

Full Text Available The triazines are a group of chemically similar herbicides including atrazine, cyanazine, and propazine, primarily used to control broadleaf weeds. About 64 to 80 million lbs of atrazine alone are used each year in the United States, making it one of the two most widely used pesticides in the country. All triazines are somewhat persistent in water and mobile in soil. They are among the most frequently detected pesticides in groundwater. They are considered as possible human carcinogens (Group C based on an increase in mammary gland tumors in female laboratory animals. In this research, we performed the Microtox Assay to investigate the acute toxicity of a significant number of triazines including atrazine, atraton, ametryne, bladex, prometryne, and propazine, and some of their degradation products including atrazine desethyl, atrazine deisopropyl, and didealkyled triazine. Tests were carried out as described by Azur Environmental [1]. The procedure measured the relative acute toxicity of triazines, producing data for the calculation of triazine concentrations effecting 50% reduction in bioluminescence (EC50s. Quantitative structure-activity relationships (QSAR were examined based on the molecular properties obtained from quantum mechanical predictions performed for each compound. Toxicity tests yielded EC50 values of 39.87, 273.20, 226.80, 36.96, 81.86, 82.68, 12.74, 11.80, and 78.50 mg/L for atrazine, propazine, prometryne, atraton, atrazine desethyl, atrazine deisopropyl, didealkylated triazine, ametryne, and bladex, respectively; indicating that ametryne was the most toxic chemical while propazine was the least toxic. QSAR evaluation resulted in a coefficient of determination (r2 of 0.86, indicating a good value of toxicity prediction based on the chemical structures/properties of tested triazines.

Establishment of 60Co dose calibration curve using fluorescent in situ hybridization assay technique: Result of preliminary study

International Nuclear Information System (INIS)

Rahimah Abdul Rahim; Noriah Jamal; Noraisyah Mohd Yusof; Juliana Mahamad Napiah; Nelly Bo Nai Lee

2010-01-01

This study aims at establishing an in-vitro 60 Co dose calibration curve using Fluorescent In-Situ Hybridization assay technique for the Malaysian National Bio dosimetry Laboratory. Blood samples collected from a female healthy donor were irradiated with several doses of 60 Co radiation. Following culturing of lymphocytes, microscopic slides are prepared, denatured and hybridized. The frequencies of translocation are estimated in the metaphases. A calibration curve was then generated using a regression technique. It shows a good fit to a linear-quadratic model. The results of this study might be useful in estimating absorbed dose for the individual exposed to ionizing radiation retrospectively. This information may be useful as a guide for medical treatment for the assessment of possible health consequences. (author)

Genetic and rat toxicity studies of cyclodextrin glucanotransferase

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Robert R. Maronpot

Full Text Available Introduction: Microbiologically derived cyclodextrin glucanotransferase (CGTase is used commercially as a processing agent in manufacture of food, pharmaceuticals, and cosmetics. Its toxic potential was evaluated in anticipation of use in the production of alpha-glycosyl isoquercitrin, a water-soluble form of quercetin. Methods: Following OECD guidelines, CGTase, produced by Bacillus pseudalcaliphilus DK-1139, was evaluated in a genotoxicity battery consisting of a bacterial reverse mutation assay, an in vitro micronucleus (MN assay and MN and comet assays using B6C3F1 male and female mice. These same genotoxicity assays were also conducted for sodium sulfate, a contaminant of CGTase preparation. In a 90-day Sprague Dawley rat toxicity study, CGTase was administered by gavage in water at daily doses of 0, 250, 500, and 1000 mg/kg/day. Results: CGTase did not induce mutations with or without metabolic activation in the bacterial reverse mutation assay. Formation of micronuclei was not induced in either in vitro or in vivo MN assays with or without metabolic activation. No induction of DNA damage was detected in male or female mouse liver, stomach, or duodenum in the comet assay. Sodium sulfate also tested negative in these same genotoxicity assays. In the 90-day repeated dose rat study there were no treatment-related adverse clinical or pathological findings. Conclusion: The genotoxicity assays and repeated dose toxicity study support the safe use of CGTase in production of alpha-glycosyl isoquercitrin. Keywords: Micronucleus assay, Comet assay, Enzymatically modified isoquercitrin (EMIQ, Food additive, Flavonol, Sodium sulfate

Repurposing CRISPR/Cas9 for in situ functional assays

NARCIS (Netherlands)

Malina, Abba; Mills, John R; Cencic, Regina; Yan, Yifei; Fraser, James; Schippers, Laura M; Paquet, Marilène; Dostie, Josée; Pelletier, Jerry

2013-01-01

RNAi combined with next-generation sequencing has proven to be a powerful and cost-effective genetic screening platform in mammalian cells. Still, this technology has its limitations and is incompatible with in situ mutagenesis screens on a genome-wide scale. Using p53 as a proof-of-principle

Facile Synthesis of Novel Coumarin Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study, ADMET Prediction and Toxicity Study

Directory of Open Access Journals (Sweden)

Shailee V. Tiwari

2017-07-01

Full Text Available The work reports the synthesis under solvent-free condition using the ionic liquid [Et3NH][HSO4] as a catalyst of fifteen novel 3-((dicyclohexylamino(substituted phenyl/heteryl-methyl-4-hydroxy-2H-chromen-2-onederivatives 4a–o as potential antimicrobial agents. The structures of the synthesized compounds were confirmed by IR, 1H-NMR, 13C-NMR, mass spectral studies and elemental analyses. All the synthesized compounds were evaluated for their in vitro antifungal and antibacterial activity. The compound 4k bearing 4-hydroxy-3-ethoxy group on the phenyl ring was found to be the most active antifungal agent. The compound 4e bearing a 2,4-difluoro group on the phenyl ring was found to be the most active antibacterial agent. The mode of action of the most promising antifungal compound 4k was established by an ergosterol extraction and quantitation assay. From the assay it was found that 4k acts by inhibition of ergosterol biosynthesis in C. albicans. Molecular docking studies revealed a highly spontaneous binding ability of the tested compounds to the active site of lanosterol 14α-demethylase, which suggests that the tested compounds inhibit the synthesis of this enzyme. The synthesized compounds were analyzed for in silico ADMET properties to establish oral drug like behavior and showed satisfactory results. To establish the antimicrobial selectivity and safety, the most active compounds 4e and 4k were further tested for cytotoxicity against human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 4e and 4k and results indicated that the compounds are non-toxic.

Review on the acute Daphnia magna toxicity test – Evaluation of the sensitivity and the precision of assays performed with organisms from laboratory cultures or hatched from dormant eggs

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Persoone G.

2009-08-01

“Culture/maintenance free” aquatic microbiotests with species of different phylogenetic groups were developed in the early 1990s at the Laboratory for Environmental Toxicology and Aquatic Ecology at the Ghent University in Belgium. These assays which were given the generic name “Toxkits”, are unique in that they employ dormant stages (“cryptobiotic eggs” of the test species, which can be stored for long periods of time and “hatched” at the time of performance of the assays. One of these microbiotests is the Daphtoxkit F magna, which is currently used in many laboratories worldwide for research as well as for toxicity monitoring purposes. The microbiotest technology has several advantages in comparison to the “traditional” tests based on laboratory cultures, especially its independence of the stock culturing burden. However, the acceptance (or possible non-acceptance of performing assays with test organisms obtained from “dormant eggs” should be clearly dictated by the “sensitivity” and “precision” criteria of the former assays in comparison to the latter. The first part of this review therefore thoroughly reviews the scientific literature and of data obtained from various laboratories for assays performed with either D. magna test organisms obtained from lab cultures or hatched from dormant eggs. Attention has focused on data of quality control tests performed on reference chemicals, and in particular on potassium dichromate (K2Cr2O7 for which an acceptability range of 0.6–2.1 mg·L–1 has been set in ISO standard 6341 for the 24 h EC50 of the acute D. magna assay. Mean EC50s, standard deviations and variation coefficients were calculated from the collected data, all of which are presented in tables and figures and discussed in detail. The major conclusions drawn from the analysis of the large number of quality control (QC data on the acute D. magna toxicity test are that : (1 Virtually all results from assays performed with

Integrating the fish embryo toxicity test as triad element for sediment toxicity assessment based on the water framework directive approach

Energy Technology Data Exchange (ETDEWEB)

Bartzke, Mariana [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Dept. Bioanalytical Ecotoxicology, Helmholtz Centre for Environmental Research, UFZ, Leipzig (Germany); Delov, Vera [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany); Gobio GmbH, Aarbergen/Kettenbach (Germany); Ecotoxicology, Fraunhofer Inst. for Molecular Biology and Applied Ecology IME, Aachen (Germany); Stahlschmidt-Allner, Petra; Allner, Bernhard [Gobio GmbH, Aarbergen/Kettenbach (Germany); Oehlmann, Joerg [Dept. Aquatic Ecotoxicology, Goethe Univ. Frankfurt am Main (Germany)

2010-04-15

Purpose: The objective of this study was to complement analyses according to the European Union Water Framework Directive (WFD) with a sediment toxicity analysis as part of an integrated river assessment. To this end, Hessian water courses were analyzed using the sediment quality triad concept according to Chapman with chemical analyses, in situ effect evaluations, and ecotoxicological assessments. For the ecotoxicological assessment (fish embryo toxicity test with Danio rerio), a new evaluation scheme was developed, the fish teratogenicity index (FTI), that allows for a classification of sediments into ecological quality classes compliant to the WFD. Materials and methods sediment and macrozoobenthos samples were taken from tributaries of the rivers Fulda and Lahn. Sediments were characterized regarding particle size, carbon, heavy metals, and polyaromatic hydrocarbon content. Macroinvertebrate samples were taken via multi-habitat sampling. The fish embryo toxicity test with D. rerio was conducted as a contact assay on the basis of DIN 38415-6. Results and discussion The integrated assessment indicated a significant influence of heavy metals and carbon content on macroinvertebrate communities. The bioaccessibility of sediment pollutants were clearly demonstrated by the FTI, which showed a wide range of adverse effects. A significant linear relationship between metals and the FTI was detected. However, there was no statistically significant evidence that macroinvertebrate communities were affected by the hydromorphological quality clements at the sampling sites. Conclusions The new scheme for the assessment of fish embryo toxicity test was successfully applied. The results suggest that sediment compounds impact macroinvertebrate communities and early development of fish. It demonstrates that the quality of sediments should be evaluated on a routine basis as part of an integrated river assessment. (orig.)

Enhancement of in situ Remediation of Hydrocarbon Contaminated Soil

Energy Technology Data Exchange (ETDEWEB)

Palmroth, M.

2006-07-01

Approximately 750 000 sites of contaminated land exist across Europe. The harmful chemicals found in Finnish soils include heavy metals, oil products, polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorophenols, and pesticides. Petroleum and petroleum products enter soil from ruptured oil pipelines, land disposal of refinery products, leaking storage tanks and through accidents. PAH contamination is caused by the spills of coal tar and creosote from coal gasification and wood treatment sites in addition to oil spills. Cleanup of soil by bioremediation is cheaper than by chemical and physical processes. However, the cleaning capacity of natural attenuation and in situ bioremediation is limited. The purpose of this thesis was to find feasible options to enhance in situ remediation of hydrocarbon contaminants. The aims were to increase the bioavailability of the contaminants and microbial activity at the subsurface in order to achieve higher contaminant removal efficiency than by intrinsic biodegradation alone. Enhancement of microbial activity and decrease of soil toxicity during remediation were estimated by using several biological assays. The performance of these assays was compared in order to find suitable indicators to follow the progress of remediation. Phytoremediation and chemical oxidation are promising in situ techniques to increase the degradation of hydrocarbons in soil. Phytoremediation is plant-enhanced decontamination of soil and water. Degradation of hydrocarbons is enhanced in the root zone by increased microbial activity and through the detoxifying enzymes of plants themselves. Chemical oxidation of contaminants by Fenton's reaction can produce degradation products which are more biodegradable than the parent compounds. Fenton's reaction and its modifications apply solutions of hydrogen peroxide and iron for the oxidation of organic chemicals. The cost of oxidation can be reduced by aiming at partial instead of full

Measurement of thyroid-stimulating autoantibodies using a radioreceptor-assay (TRAK-assay)

International Nuclear Information System (INIS)

Becker, W.; Reiners, C.; Boerner, W.

1983-01-01

Autoantibodes against TSH-receptors were determined with a new radioreceptorassay (TRAK-assay) in 37 patients with untreated toxic diffus goitre and in 73 patients with non immunogenic thyroid diseases (41 healthy controls, respectively patients with euthyroid diffus or nodular goitres as well as 32 patients with toxic nodular goitre). The upper limit of normal is a TRAK-Titer of 20% without considerable fluctuations during titers in follow-up. According to this preliminary results it seems to be recommendable to treat patients with TRAK-titer F 20% (expected risk of relapse) primarily by operation or radioiodine. (orig.) [de

Metabolism Retrofit Strategies for ToxCast Assays (BOSC)

Science.gov (United States)

The EPA’s ToxCast program utilizes a wide variety of high-throughput screening assays (HTS) to assess chemical perturbations of molecular and cellular endpoints. A limitation of many HTS assays used for toxicity assessment is the lack of xenobiotic metabolism (XM) which precludes...

Altered apoptotic profiles in irradiated patients with increased toxicity

International Nuclear Information System (INIS)

Crompton, Nigel E.A.; Miralbell, Raymond; Rutz, Hans-Peter; Ersoy, Fuegen; Sanal, Oezden; Wellmann, Danielle; Bieri, Sabine; Coucke, Philippe A.; Emery, Gillian C.; Shi Yuquan; Blattmann, Hans; Ozsahin, Mahmut

1999-01-01

Purpose: A retrospective study of radiation-induced apoptosis in CD4 and CD8 T-lymphocytes, from 12 cancer patients who displayed enhanced toxicity to radiation therapy and 9 ataxia telangiectasia patients, was performed to test for altered response compared to healthy blood-donors and normal cancer patients. Methods and Materials: Three milliliters of heparinized blood from each donor was sent via express post to the Paul Scherrer Institute (PSI) for subsequent examination. The blood was diluted 1:10 in RPMI medium, irradiated with 0-, 2-, or 9-Gy X-rays, and incubated for 48 h. CD4 and CD8 T-lymphocytes were then labeled using FITC-conjugated antibodies, erythrocytes were lysed, and the DNA stained with propidium iodide. Subsequently, cells were analyzed using a Becton Dickinson FACScan flow cytometer. Radiation-induced apoptosis was recognized in leukocytes as reduced DNA content attributed to apoptosis-associated changes in chromatin structure. Apoptosis was confirmed by light microscopy, electron microscopy, and by the use of commercially available apoptosis detection kits (in situ nick translation and Annexin V). Data from hypersensitive individuals were compared to a standard database of 105 healthy blood-donors, and a database of 48 cancer patient blood donors who displayed normal toxicity to radiation therapy. To integrate radiosensitivity results from CD4 and CD8 T-lymphocytes after 2 and 9 Gy, z-score analyses were performed. Results: A cohort of 12 hypersensitive patients was evaluated; 8 showed enhanced early toxicity, 3 showed enhanced late toxicity, and 1 showed both. The cohort displayed less radiation-induced apoptosis (-1.8 σ) than average age-matched donors. A cohort of 9 ataxia telangiectasia homozygotes displayed even less apoptosis (-3.6 σ). Conclusion: The leukocyte apoptosis assay appears to be a useful predictor of individuals likely to display increased toxicity to radiation therapy; however, validation of this requires a prospective

Toxic Potential of Synthesized Graphene Zinc Oxide Nanocomposite in the Third Instar Larvae of Transgenic Drosophila melanogaster (hsp70-lacZBg9

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Yasir Hasan Siddique

2014-01-01

Full Text Available In the present study the graphene zinc oxide nanocomposite (GZNC was synthesized, characterized, and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZBg9. The synthesized GZNC was characterized by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. The GZNC in 0.1% dimethyl sulphoxide (DMSO was sonicated for 10 minutes and the final concentrations 0.033, 0.099, 0.199, and 3.996 μg/μL of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hr. The hsp70 expression was measured by o-nitrophenyl-β-D-galactopyranoside assay, tissue damage was measured by trypan blue exclusion test, and β-galactosidase activity was monitored by in situ histochemical β-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 μg/μL of GZNC was toxic for both 24 hr and 48 hr of exposure. The doses of 0.033 μg/μL and 0.099 of GZNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hr of duration.

An integrated approach to improved toxicity prediction for the safety assessment during preclinical drug development using Hep G2 cells

International Nuclear Information System (INIS)

Noor, Fozia; Niklas, Jens; Mueller-Vieira, Ursula; Heinzle, Elmar

2009-01-01

Efficient and accurate safety assessment of compounds is extremely important in the preclinical development of drugs especially when hepatotoxicty is in question. Multiparameter and time resolved assays are expected to greatly improve the prediction of toxicity by assessing complex mechanisms of toxicity. An integrated approach is presented in which Hep G2 cells and primary rat hepatocytes are compared in frequently used cytotoxicity assays for parent compound toxicity. The interassay variability was determined. The cytotoxicity assays were also compared with a reliable alternative time resolved respirometric assay. The set of training compounds consisted of well known hepatotoxins; amiodarone, carbamazepine, clozapine, diclofenac, tacrine, troglitazone and verapamil. The sensitivity of both cell systems in each tested assay was determined. Results show that careful selection of assay parameters and inclusion of a kinetic time resolved assay improves prediction for non-metabolism mediated toxicity using Hep G2 cells as indicated by a sensitivity ratio of 1. The drugs with EC 50 values 100 μM or lower were considered toxic. The difference in the sensitivity of the two cell systems to carbamazepine which causes toxicity via reactive metabolites emphasizes the importance of human cell based in-vitro assays. Using the described system, primary rat hepatocytes do not offer advantage over the Hep G2 cells in parent compound toxicity evaluation. Moreover, respiration method is non invasive, highly sensitive and allows following the time course of toxicity. Respiration assay could serve as early indicator of changes that subsequently lead to toxicity.

Assessment of Individual and Combined Toxicities of Four Non-Essential Metals (As, Cd, Hg and Pb in the Microtox Assay

Directory of Open Access Journals (Sweden)

Paul B. Tchounwou

2006-03-01

Full Text Available Although most researches with non-essential metals (NEMs have been done with single or individual metals, in reality, organisms are often exposed to multiple contaminants at the same time through the air, food and water. In this study, we tested the toxicity of four NEMs, As, Cd, Pb, and Hg, individually and as a composite mixture using the microtox bioassay. This assay uses the reduction of bioluminescence of the bacterium Vibrio fischeri as a measure of toxicity. The concentrations of each chemical in the mixture were based on multiples of their maximum contaminant levels (MCLs set by the U.S. EPA. The highest concentration of exposure was 20 times the MCL, which translated into 200, 100, 40 and 300 ppb for As, Cd, Hg and Pb, respectively. The ratio for the mixture from these concentrations was 10:5:2:15 for As, Cd, Hg and Pb, respectively. Among the individual metals tested, the ranking of toxicity was Hg>Pb>Cd>As based on the EC50 values of 109, 455, 508 and 768 ppb for Hg, Pb, Cd and As, respectively. The EC50 for the composite mixture was 495% MCL which translated into nominal concentrations of 49, 25, 10 and 74 ppb for As, Cd, Hg, and Pb, respectively. Overall, the EC50 value of each NEM within the mixture was lower than the EC50 of the individual chemical; an evidence of synergism for the mixture. The individual toxic units (TU were 0.06, 0.05, 0.09, and 0.16 for As, Cd Hg, and Pb, respectively and the summed toxic unit (TU was 0.37 (less than 1. This study provides needed scientific data necessary for carrying out complete risk assessment of As, Cd, Hg, and Pb mixtures of some priority compounds.

Monkey Feeding Assay for Testing Emetic Activity of Staphylococcal Enterotoxin.

Science.gov (United States)

Seo, Keun Seok

2016-01-01

Staphylococcal enterotoxins (SEs) are unique bacterial toxins that cause gastrointestinal toxicity as well as superantigenic activity. Since systemic administration of SEs induces superantigenic activity leading to toxic shock syndrome that may mimic enterotoxic activity of SEs such as vomiting and diarrhea, oral administration of SEs in the monkey feeding assay is considered as a standard method to evaluate emetic activity of SEs. This chapter summarizes and discusses practical considerations of the monkey feeding assay used in studies characterizing classical and newly identified SEs.

UV/H2O2 advanced oxidation for abatement of organophosphorous pesticides and the effects on various toxicity screening assays.

Science.gov (United States)

Parker, Austa M; Lester, Yaal; Spangler, Emily K; von Gunten, Urs; Linden, Karl G

2017-09-01

Advanced oxidation processes (AOPs) are utilized due to their ability to treat emerging contaminants with the fast reacting and non-selective hydroxyl radical (OH). Organophosphorous insecticides are common drinking water contaminants, with 12 different compounds of this class being found on the US EPA's most recent Candidate Contaminant List (CCL4). The use of the AOP UV/H 2 O 2 for the treatment of organophosphorous insecticides was explored in this study, by coupling biological and analytical tools to follow the abatement of the target compounds. Four insecticides were explored for advanced oxidation treatment: acephate, dicrotophos, fenamiphos, and methamidophos. All four compounds were fast reacting with OH, all reacting with second order rate constants ≥5.5 × 10 9  M -1 s -1 . Three major endpoints of toxicity were studied: estrogenicity, genotoxicity (mutagenicity) and neurotoxicity. None of the target compounds showed any estrogenic activity, while all compounds showed an active genotoxic (mutagenic) response (AMES II assay) and most compounds had some level of neurotoxic activity. AOP treatment did not induce any estrogenic activity, and reduced the compounds' neurotoxicity and genotoxicity in all but one case. Methamidophos degradation by UV/H 2 O 2 resulted in an increase in genotoxicity, likely due to the formation of toxic transformation products. The increase in toxicity gradually decreased with time, possibly due to hydrolysis of the transformation products formed. This study provides insights into parent compound abatement and the changes in toxicity due to transformation products. Copyright © 2017 Elsevier Ltd. All rights reserved.

The comet assay in Environmental Risk Assessment of marine pollutants: applications, assets and handicaps of surveying genotoxicity in non-model organisms.

Science.gov (United States)

Martins, Marta; Costa, Pedro M

2015-01-01

Determining the genotoxic effects of pollutants has long been a priority in Environmental Risk Assessment (ERA) for coastal ecosystems, especially of complex areas such as estuaries and other confined waterbodies. The acknowledged link between DNA damage, mutagenicity and carcinogenicity to the exposure to certain toxicants has been responsible to the growing interest in determining the genotoxic effects of xenobiotics to wildlife as a measure of environmental risk. The comet assay, although widely employed in in vivo and in vitro toxicology, still holds many constraints in ERA, in large part owing to difficulties in obtaining conclusive cause-effect relationships from complex environments. Nevertheless, these challenges do not hinder the attempts to apply the alkaline comet assay on sentinel organisms, wild or subjected to bioassays in or ex situ (from fish to molluscs) as well to standardise protocols and establish general guidelines to the interpretation of findings. Fish have been regarded as an appealing subject due to the ease of performing the comet assay in whole blood. However, the application of the comet assay is becoming increasingly common in invertebrates (e.g. in molluscan haemocytes and solid tissues such as gills). Virtually all sorts of results have been obtained from the application of the comet assay in ERA (null, positive and inconclusive). However, it has become clear that interpreting DNA damage data from wild organisms is particularly challenging due to their ability to adapt to continuous environmental stressors, including toxicants. Also, the comet assay in non-model organisms for the purpose of ERA implies different constraints, assumptions and interpretation of findings, compared with the in vitro procedures from which most guidelines have been derived. This paper critically reviews the application of the comet assay in ERA, focusing on target organisms and tissues; protocol developments, case studies plus data handling and

Monosodium Glutamate Toxicity

African Journals Online (AJOL)

Dr Olaleye

The brain is reportedly sensitive to monosodium glutamate (MSG) toxicity via oxidative stress. Sida acuta leaf ethanolic .... wherein the right hemisphere, was preserved for histology and fixed in 10% ... Biochemical Assays: The left hemisphere of the brain samples was ...... development in male and female rats. Exp Physiol.

Aminopropyltriethoxysilane-mediated surface functionalization of hydroxyapatite nanoparticles: synthesis, characterization, and in vitro toxicity assay

Directory of Open Access Journals (Sweden)

Wang S

2011-12-01

Full Text Available Shige Wang1, Shihui Wen2, Mingwu Shen2, Rui Guo2, Xueyan Cao2, Jianhua Wang3, Xiangyang Shi1,2,41State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, 2College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, 3Department of Biochemistry and Molecular Cell Biology, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China; 4Centro de Química da Madeira, Universidade da Madeira, Campus da Penteada, Funchal, PortugalBackground: We report on aminopropyltriethoxysilane (APTS-mediated surface modification of nanohydroxyapatite with different surface functional groups for potential biomedical applications. In this study, nanohydroxyapatite covalently linked with APTS (n-HA-APTS was reacted with acetic anhydride or succinic anhydride to produce neutralized (n-HA-APTS.Ac or negatively charged (n-HA-APTS.SAH nanohydroxyapatite, respectively. Nanohydroxyapatite formed with amine, acetyl, and carboxyl groups was extensively characterized using Fourier transform infrared spectroscopy, transmission electron microscopy, 1H nuclear magnetic resonance spectroscopy, X-ray diffraction, inductively coupled plasma-atomic emission spectroscopy, and zeta potential measurements.Results: In vitro 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide colorimetric assay revealed that the slight toxicity of the amine-functionalized n-HA-APTS could be eliminated by post-functionalization of APTS amines to form acetyl and carboxyl groups. Blood compatibility assessment demonstrated that the negligible hemolytic activity of the pristine nanohydroxyapatite particles did not appreciably change after APTS-mediated surface functionalization.Conclusion: APTS-mediated functionalization of nanohydroxyapatite with different surface groups may be useful for further functionalization of nanohydroxyapatite with biologically active materials, thereby providing possibilities for a broad range of

MONITORING THE AIR FOR TOXIC AND GENOTOXIC COMPOUNDS

Science.gov (United States)

A time-integrated sampling system interfaced with a toxicity-based assay is reported for monitoring volatile toxic industrial chemicals (TICs). Semipermeable membrane devices (SPMDs) using dimethyl sulfoxide (DMSO) as the fill solvent accumulated each of 17 TICs from the vapor p...

CYTOTOXICITY AND MUTAGENESIS METHODS FOR EVALUATING TOXICITY REMOVAL FROM WASTEWATERS

Science.gov (United States)

This project was a feasibility study of the effectiveness of a mammalian cell cytotoxicity assay and a mammalian cell mutagenesis assay for monitoring the toxicity and mutagenicity of influent and effluent wastewater at treatment plants. In the cytotoxicity assay, ambient samples...

Toxicоlogical evaluation of the plant products using Brine Shrimp (Artemia salina L. model

Directory of Open Access Journals (Sweden)

Меntor R. Hamidi

2014-04-01

Full Text Available Many natural products could serve as the starting point in the development of modern medicines because of their numerous biological and pharmacological activities. However, some of them are known to carry toxicological properties as well. In order to achieve a safe treatment with plant products, numerous research studies have recently been focused on both pharmacology and toxicity of medicinal plants. Moreover, these studies employed efforts for alternative biological assays. Brine Shrimp Lethality Assay is the most convenient system for monitoring biological activities of various plant species. This method is very useful for preliminary assessment of toxicity of the plant extracts. Rapidness, simplicity and low requirements are several advantages of this assay. However, several conditions need to be completed, especially in the means of standardized experimental conditions (temperature, pH of the medium, salinity, aeration and light. The toxicity of herbal extracts using this assay has been determined in a concentration range of 10, 100 and 1000 µg/ml of the examined herbal extract. Most toxicity studies which use the Brine Shrimp Lethality Assay determine the toxicity after 24 hours of exposure to the tested sample. The median lethal concentration (LC50 of the test samples is obtained by a plot of percentage of the dead shrimps against the logarithm of the sample concentration. LC50 values are estimated using a probit regression analysis and compared with either Meyer’s or Clarkson’s toxicity criteria. Furthermore, the positive correlation between Meyer’s toxicity scale for Artemia salina and Gosselin, Smith and Hodge’s toxicity scale for higher animal models confirmed that the Brine Shrimp Lethality Assay is an excellent predictive tool for the toxic potential of plant extracts in humans.

Development of Medical Technology for Contingency Response to Marrow Toxic Agents

Science.gov (United States)

2014-05-06

Specific Oligonucleotides SSP Sequence Specific Primers SSOP Sequence Specific Oligonucleotide Probes STAR ® Search, Tracking and Registry TBI Total... white paper detailing recommendations/guidelines for the assessment of new assays (potency or other assays) relevant to cord blood banking and/or...Irradiation - Marcel van den Brink (Memorial Sloan Kettering Cancer Center) 5. Organ Toxicity: h. Pulmonary Toxicity - Zeljko Vujaskovic (Duke) i

Experimental Assays to Assess the Efficacy of Vinegar and Other Topical First-Aid Approaches on Cubozoan (Alatina alata) Tentacle Firing and Venom Toxicity.

Science.gov (United States)

Yanagihara, Angel A; Wilcox, Christie; King, Rebecca; Hurwitz, Kikiana; Castelfranco, Ann M

2016-01-11

Despite the medical urgency presented by cubozoan envenomations, ineffective and contradictory first-aid management recommendations persist. A critical barrier to progress has been the lack of readily available and reproducible envenomation assays that (1) recapitulate live-tentacle stings; (2) allow quantitation and imaging of cnidae discharge; (3) allow primary quantitation of venom toxicity; and (4) employ rigorous controls. We report the implementation of an integrated array of three experimental approaches designed to meet the above-stated criteria. Mechanistically overlapping, yet distinct, the three approaches comprised (1) direct application of test solutions on live tentacles (termed tentacle solution assay, or TSA) with single image- and video-microscopy; (2) spontaneous stinging assay using freshly excised tentacles overlaid on substrate of live human red blood cells suspended in agarose (tentacle blood agarose assays, or TBAA); and (3) a "skin" covered adaptation of TBAA (tentacle skin blood agarose assay, or TSBAA). We report the use and results of these assays to evaluate the efficacy of topical first-aid approaches to inhibit tentacle firing and venom activity. TSA results included the potent stimulation of massive cnidae discharge by alcohols but only moderate induction by urine, freshwater, and "cola" (carbonated soft drink). Although vinegar, the 40-year field standard of first aid for the removal of adherent tentacles, completely inhibited cnidae firing in TSA and TSBAA ex vivo models, the most striking inhibition of both tentacle firing and subsequent venom-induced hemolysis was observed using newly-developed proprietary formulations (Sting No More™) containing copper gluconate, magnesium sulfate, and urea.

A comparison of sediment toxicity test methods at three Great Lake Areas of Concern

Science.gov (United States)

Burton, G. Allen; Ingersoll, Christopher G.; Burnett, LouAnn C.; Henry, Mary; Hinman, Mark L.; Klaine, Stephen J.; Landrum, Peter F.; Ross, Phillipe; Tuchman, Marc

1996-01-01

The significance of sediment contamination is often evaluated using sediment toxicity (bioassay) testing. There are relatively few “standardized” test methods for evaluating sediments. Popular sediment toxicity methods examine the extractable water (elutriate), interstitial water, or whole (bulk) sediment phases using test species spanning the aquatic food chain from bacteria to fish. The current study was designed to evaluate which toxicity tests were most useful in evaluations of sediment contamination at three Great Lake Areas of Concern. Responses of 24 different organisms including fish, mayflies, amphipods, midges, cladocerans, rotifers, macrophytes, algae, and bacteria were compared using whole sediment or elutriate toxicity assays. Sediments from several sites in the Buffalo River, Calumet River (Indiana Harbor), and Saginaw River were tested, as part of the U.S. Environmental Protection Agency's (USEPA) Assessment and Remediation of Contaminated Sediments (ARCS) Project. Results indicated several assays to be sensitive to sediment toxicity and able to discriminate between differing levels of toxicity. Many of the assay responses were significantly correlated to other toxicity responses and were similar based on factor analysis. For most applications, a test design consisting of two to three assays should adequately detect sediment toxicity, consisting of various groupings of the following species: Hyalella azteca, Ceriodaphnia dubia, Chironomus riparius, Chironomus tentans, Daphnia magna, Pimephales promelas, Hexagenia bilineata, Diporeia sp., Hydrilla verticillata, or Lemna minor.

Temperature influence on chemical toxicity to aquatic organisms

International Nuclear Information System (INIS)

Cairns, J. Jr.; Heath, A.G.; Parker, B.C.

1975-01-01

The literature on the effects of temperature on chemical toxicity to aquatic animals and microorganisms is reviewed. Microbial photosynthesis and respiration is briefly discussed. It is concluded that there is a paucity of information on the inter-relations of temperature and toxicants to algae, bacteria, and protozoa and that standards based on the in situ response of indigenous organisms to specific discharge areas should be developed

Toxic effect evaluation of the lead acetate and chromium chloride on anaerobic bacterial metabolism

International Nuclear Information System (INIS)

Wills, Beatriz; Naranjo, Fernando

2004-01-01

The toxicity of trivalent chromium and lead to anaerobic sludge system was studied. Performed assay was tested in 60 mL serum vials, the toxicity test to succeed in two steps, first with formic acid and then whey powder as a substrate. Anaerobic toxicity assays were performed taking into account, methane gas production and oxidation-reduction potential (ORP) rate, these tests were considered a useful indicator for monitoring a anaerobic sludge suffering from toxicants, over 72 hours with metals dosage against the control. First of all, exploratory assays in order to know different chromium and lead concentrations were carried out. The assays degradation activity reduced methane by 50% that came into contact with 3.322 mg Cr 3 +/L and 1.415 mg Pb/L and 2.291 mg Cr 3 +/Land 1.982 mg Pb/L with formic acid and whey powder as a substrate respectively. Heavy metal concentrations that caused 50% inhibition of methanogenesis during whey and formic acid methanation indicated that toxicity decreased in order Pb>>Cr

Bio-testing integral toxicity of corrosion inhibitors, biocides and oil hydrocarbons in oil-and gas-processing industry

Energy Technology Data Exchange (ETDEWEB)

Chugunov, V.A.; Kholodenko, V.P.; Irkhina, I.A.; Fomchenkov, V.M.; Novikov, I.A. [State Research Center for Applied Microbiology, Obolensk, Moscow (Russian Federation)

2004-07-01

In recent years bioassays have been widely used for assessing levels of contamination of the environment. This is due to the fact that test-organisms provide a general response to toxicants present in samples. Based on microorganisms as test objects, it is possible to develop cheap, sensitive and rapid assays to identify environmental xenobiotics and toxicants. The objective of the research was to develop different microbiological assays for assessing integral toxicity of water environments polluted with corrosion inhibitors, biocides and hydrocarbons in oil- and gas-processing industry. Bio-luminescent, electro-orientational, osmo-optic and microorganism reducing activity assays were used for express evaluation of integral toxicity. They are found to determine promptly integral toxicity of water environments containing various pollutants (oil, oil products, corrosion inhibitors, biocides). Results conclude that the assays may be used for analyzing integral toxicity of water polluted with hydrocarbons, as well as for monitoring of water changes as a result of biodegradation of pollutants by microorganisms and their associations. Using a kit of different assays, it is also possible to evaluate ecological safety of biocides, corrosion inhibitors, and their compositions. Bioassays used as a kit are more effective than each assay individually, allowing one to get complete characterization of a reaction of bacterial test organisms to different environments. (authors)

Assessment of the Microscreen phage-induction assay for screening hazardous wastes

Energy Technology Data Exchange (ETDEWEB)

Houk, V.S.; DeMarini, D.M.

1987-09-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s(lambda), was used to test 14 crude (unfractionated) hazardous industrial waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 picograms per ml. Comparisons between the mutagenicity of these waste samples in Salmonella and their ability to induce prophage lambda indicate that the Microscreen phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic 5 additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed along with some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

Assay for the developmental toxicity of safflower (Carthamus tinctorius L. to zebrafish embryos/larvae

Directory of Open Access Journals (Sweden)

Qing Xia

2017-01-01

Conclusion: Safflower exhibits developmental toxicity for zebrafish embryos/larvae. The developing heart was speculated as the target organ of toxicity. Oxidative stress and increased apoptosis have roles in the developmental toxicity of safflower. This article provides a novel method to research the teratogenicity and possible mechanisms of toxicity of traditional Chinese medicines that are prohibited or contraindicated in pregnant women.

Predicting the risk of developmental toxicity from in vitro assays

International Nuclear Information System (INIS)

Spielmann, Horst

2005-01-01

Reproductive toxicity refers to the adverse effects of a substance on any aspect of the reproductive cycle, including the impairment of reproductive function, the induction of adverse effects in the embryo, such as growth retardation, malformations, and death. Due to the complexity of the mammalian reproductive cycle, it is impossible to model the whole cycle in a single in vitro system in order to detect chemical effects on mammalian reproduction. However, the cycle can be broken down in its biological components which may be studied individually or in combination. This approach has the advantage that the target tissue/organ of a developmental toxicant can be identified. In specific areas of developmental toxicity, a number of useful and promising in vitro models are already available. The individual tests may be used as building blocks of a tiered testing strategy. So far, research has focused on developing and validating tests covering only a few components of the reproductive cycle, in particular organogenesis of the embryo, reflecting important concerns for teratogenic chemicals. During the last three decades, a number of established models and promising new developments have emerged that will be discussed, e.g. culture of mammalian embryos and embryonic cells and tissues and the use of embryonic stem cells

Toxicity testing of human assisted reproduction devices using the mouse embryo assay.

NARCIS (Netherlands)

Punt-Van der Zalm, J.P.; Hendriks, J.C.M.; Westphal, J.R.; Kremer, J.A.M.; Teerenstra, S.; Wetzels, A.M.M.

2009-01-01

Systems to assess the toxicity of materials used in human assisted reproduction currently lack efficiency and/or sufficient discriminatory power. The development of 1-cell CBA/B6 F1 hybrid mouse embryos to blastocysts, expressed as blastocyst rate (BR), is used to measure toxicity. The embryos were

Effect of soil contaminant extraction method in determining toxicity using the Microtox(reg.) assay

International Nuclear Information System (INIS)

Harkey, G.A.; Young, T.M.

2000-01-01

This project examined the influence of different extraction methods on the measured toxicity of contaminated soils collected from manufactured gas plant (MGP) sites differing in soil composition and contaminant concentration. Aged soils from a number of MGP sites were extracted using a saline solution, supercritical fluid extraction (SFE), and Soxhlet extraction. Toxicity was assessed using two forms of Microtox tests: acute aqueous tests on saline and SFE soil extracts and solid-phase tests (SPTs) on soil particles. Microtox SPTs were performed on soils before and after SFE to determine resulting toxicity reduction. Three hypotheses were tested: (1) Toxicity of soil extracts is related to contaminant concentrations of the extracts, (2) measured toxicity significantly decreases with less vigorous methods of extraction, and (3) supercritical fluid extractability correlates with measured toxicity. The EC50s for SPTs performed before and after SFE were not different for some soils but were significantly greater after extraction for other soils tested. The most significant toxicity reductions were observed for soils exhibiting the highest toxicity in both preextraction SPTs and acute aqueous tests. Acute Microtox tests performed on SFE extracts showed significantly lower EC50s than those reported from saline-based extraction procedures. Toxicity of the soils measured by Microtox SPTs was strongly correlated with both SFE efficiency and measures of contaminant aging. Data from this project provide evidence of sequestration and reduced availability of polycyclic aromatic hydrocarbons (PAHs) from soils extracted via physiologically based procedures compared to vigorous physical extraction protocols

Application of cell-based assays for toxicity characterization of complex wastewater matrices: Possible applications in wastewater recycle and reuse.

Science.gov (United States)

Shrivastava, Preeti; Naoghare, Pravin K; Gandhi, Deepa; Devi, S Saravana; Krishnamurthi, Kannan; Bafana, Amit; Kashyap, Sanjay M; Chakrabarti, Tapan

2017-08-01

Exposure to pre-concentrated inlet or outlet STP wastewater extracts at different concentrations (0.001% to 1%) induced dose-dependent toxicity in MCF-7 cells, whereas drinking water extracts did not induce cytotoxicity in cells treated. GC-MS analysis revealed the occurrence of xenobiotic compounds (Benzene, Phthalate, etc.) in inlet/outlet wastewater extracts. Cells exposed to inlet/outlet extract showed elevated levels of reactive oxygen species (ROS: inlet: 186.58%, ploss of mitochondrial membrane potential (Δψm: inlet, 74.91%, pcontrol. These concentrations induced DNA damage (Tail length: inlet: 34.4%, pcontrol (Tail length: 7.5%). Cell cycle analysis displayed drastic reduction in the G1 phase in treated cells (inlet, G1:45.0%; outlet, G1:58.3%) compared to the control (G1:67.3%). Treated cells showed 45.18% and 28.0% apoptosis compared to the control (1.2%). Drinking water extracts did not show any significant alterations with respect to ROS, Δψm, DNA damage, cell cycle and apoptosis compared to the control. Genes involved in cell cycle and apoptosis were found to be differentially expressed in cells exposed to inlet/outlet extracts. Herein, we propose cell-based toxicity assays to evaluate the efficacies of wastewater treatment and recycling processes. Copyright © 2017 Elsevier Inc. All rights reserved.

Vanadium bioavailability and toxicity to soil microorganisms and plants.

Science.gov (United States)

Larsson, Maja A; Baken, Stijn; Gustafsson, Jon Petter; Hadialhejazi, Golshid; Smolders, Erik

2013-10-01

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting properties were spiked with 7 different doses (3.2-3200 mg V kg(-1)) of dissolved vanadate, and toxicity was measured with 2 microbial and 3 plant assays. The median effective concentration (EC50) thresholds of the microbial assays ranged from 28 mg added V kg(-1) to 690 mg added V kg(-1), and the EC50s in the plant assays ranged from 18 mg added V kg(-1) to 510 mg added V kg(-1). The lower thresholds were in the concentration range of the background vanadium in the untreated control soils (15-58 mg V kg(-1)). The vanadium toxicity to plants decreased with a stronger soil vanadium sorption strength. The EC50 values for plants expressed on a soil solution basis ranged from 0.8 mg V L(-1) to 15 mg V L(-1) and were less variable among soils than corresponding values based on total vanadium in soil. It is concluded that sorption decreases the toxicity of added vanadate and that soil solution vanadium is a more robust measure to determine critical vanadium concentrations across soils. © 2013 SETAC.

Using quantitative structure-activity relationships (QSAR) to predict toxic endpoints for polycyclic aromatic hydrocarbons (PAH).

Science.gov (United States)

Bruce, Erica D; Autenrieth, Robin L; Burghardt, Robert C; Donnelly, K C; McDonald, Thomas J

2008-01-01

Quantitative structure-activity relationships (QSAR) offer a reliable, cost-effective alternative to the time, money, and animal lives necessary to determine chemical toxicity by traditional methods. Additionally, humans are exposed to tens of thousands of chemicals in their lifetimes, necessitating the determination of chemical toxicity and screening for those posing the greatest risk to human health. This study developed models to predict toxic endpoints for three bioassays specific to several stages of carcinogenesis. The ethoxyresorufin O-deethylase assay (EROD), the Salmonella/microsome assay, and a gap junction intercellular communication (GJIC) assay were chosen for their ability to measure toxic endpoints specific to activation-, induction-, and promotion-related effects of polycyclic aromatic hydrocarbons (PAH). Shape-electronic, spatial, information content, and topological descriptors proved to be important descriptors in predicting the toxicity of PAH in these bioassays. Bioassay-based toxic equivalency factors (TEF(B)) were developed for several PAH using the quantitative structure-toxicity relationships (QSTR) developed. Predicting toxicity for a specific PAH compound, such as a bioassay-based potential potency (PP(B)) or a TEF(B), is possible by combining the predicted behavior from the QSTR models. These toxicity estimates may then be incorporated into a risk assessment for compounds that lack toxicity data. Accurate toxicity predictions are made by examining each type of endpoint important to the process of carcinogenicity, and a clearer understanding between composition and toxicity can be obtained.

In situ detection of estrogen receptor dimers in breast carcinoma cells in archival materials using proximity ligation assay (PLA).

Science.gov (United States)

Iwabuchi, Erina; Miki, Yasuhiro; Ono, Katsuhiko; Onodera, Yoshiaki; Suzuki, Takashi; Hirakawa, Hisashi; Ishida, Takanori; Ohuchi, Noriaki; Sasano, Hironobu

2017-01-01

Estrogen receptor (ER) is required for carcinoma cell proliferation in the great majority of breast cancer and also functions as a dimer. ER dimeric proteins have been largely identified by BRET/FRET analyses but their in situ visualization have not yet been reported. Recently, in situ Proximity Ligation Assay (PLA) has been developed as the methods detecting protein interactions in situ. Therefore, in this study we firstly demonstrated the dimerization of ERα in breast carcinoma cell lines and tissues using PLA. The human breast carcinoma cell lines MCF-7, T-47D and MDA-MB-231 were used in this study. Cells were treated with ER agonist or antagonist and fixed in 4% PFA, and ER dimers were subsequently detected using PLA. The evaluation of ER dimers in breast carcinoma cell lines were quantified by measuring the area of dots localized in the nuclei using image analysis. We also firstly demonstrated the visualization of ER dimer patterns in 10% formalin-fixed paraffin-embedded tissues of breast cancer using PLA technique. Estradiol (E2) administration induced ERα homodimers in the nuclei of MCF-7 and T-47D but not in ER-negative MDA-MB-231. 4-OH tamoxifen also induced ERα homodimers but the subcellular localization of these ERα homodimers was predominant in cytoplasm instead of the nuclei induced by E2 treatment. ICI182,780 treatment did decrease the number of formation of ERα homodimers in MCF-7. In breast cancer patients, ERα PLA score was significantly correlated positively with ERα- or PgR (progesterone receptor) immunohistochemical scores and inversely with Ki-67-labeling index, respectively. We also demonstrated the ERα/β heterodimer as well as ERα homodimers in both breast carcinoma cell lines and surgical pathology specimens. In summary, we did firstly succeed in the visualization of ER dimeric proteins using PLA method. The evaluation of ER dimer patterns could provide pivotal information as to the prediction of response to endocrine therapy of

In Situ Loading of Basic Fibroblast Growth Factor Within Porous Silica Nanoparticles for a Prolonged Release

Directory of Open Access Journals (Sweden)

Postovit Lynne-Marie

2009-01-01

Full Text Available Abstract Basic fibroblast growth factor (bFGF, a protein, plays a key role in wound healing and blood vessel regeneration. However, bFGF is easily degraded in biologic systems. Mesoporous silica nanoparticles (MSNs with well-tailored porous structure have been used for hosting guest molecules for drug delivery. Here, we report an in situ route to load bFGF in MSNs for a prolonged release. The average diameter (d of bFGF-loaded MSNs is 57 ± 8 nm produced by a water-in-oil microemulsion method. The in vitro releasing profile of bFGF from MSNs in phosphate buffer saline has been monitored for 20 days through a colorimetric enzyme linked immunosorbent assay. The loading efficiency of bFGF in MSNs is estimated at 72.5 ± 3%. In addition, the cytotoxicity test indicates that the MSNs are not toxic, even at a concentration of 50 μg/mL. It is expected that the in situ loading method makes the MSNs a new delivery system to deliver protein drugs, e.g. growth factors, to help blood vessel regeneration and potentiate greater angiogenesis.

Evaluation of the repeated-dose liver micronucleus assay using 2,4-dinitrotoluene: a report of a collaborative study by CSGMT/JEMS.MMS.

Science.gov (United States)

Maeda, Akihisa; Tsuchiyama, Hiromi; Asaoka, Yoshiji; Hirakata, Mikito; Miyoshi, Tomoya; Oshida, Keiyu; Miyamoto, Yohei

2015-03-01

The liver micronucleus assay using young adult rats has the potential to detect liver carcinogens by repeated dosing, and could be expected to be integrated into repeated-dose toxicity studies using a hepatocyte isolation method without the traditional in situ collagenase perfusion. In this study, to assess the performance of the repeated-dose liver micronucleus assay, 2,4-dinitrotoluene (DNT), which is a rodent liver carcinogen, was administered orally to male rats at doses of 50, 100 and 200 mg/kg/day once daily for 14 or 28 consecutive days, and the frequencies of micronucleated hepatocytes (MNHEPs) and micronucleated immature erythrocytes (MNIMEs) were examined. Significant increases in the MNHEPs were observed at 50 mg/kg/day or more in the 14-day treatment, and 50 and 100 mg/kg/day in the 28-day treatment. These increases were dependent on both the dose and the number of administrations, which indicates the possibility that the MNHEPs accumulate as a result of repeated dosing. In contrast, no increase in the MNIMEs was observed. In conclusion, the repeated-dose liver micronucleus assay using young adult rats is sufficiently sensitive to detect the genotoxicity of 2,4-DNT at a low dose.

Ionic Liquid-Promoted Synthesis of Novel Chromone-Pyrimidine Coupled Derivatives, Antimicrobial Analysis, Enzyme Assay, Docking Study and Toxicity Study

Directory of Open Access Journals (Sweden)

Shailee V. Tiwari

2018-02-01

Full Text Available Herein, we report an environmentally friendly, rapid, and convenient ionic liquid ([Et3NH][HSO4]-promoted facile synthesis of ethyl 4-(6-substituted-4-oxo-4H-chromen-3-yl-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5-carboxylate derivatives 4(a–f and 4-(6-substituted-4-oxo-4H-chromen-3-yl-6-methyl-2-thioxo/oxo-1,2,3,4-tetrahydropyrimidine-5- carbohydrazide derivatives 6(a–f. All the synthesized derivatives 4(a–f and 6(a–f were evaluated for their in vitro antifungal and antibacterial activity, by method recommended by National Committee for Clinical Laboratory Standards (NCCLS. The compound 6c bearing a fluoro group on the chromone ring and oxygen and a hydrazino group (–NHNH2 on the pyrimidine ring, was found to be the most potent antibacterial compound amongst the synthesized derivatives. The compound 6f bearing a methoxy group (–OCH3 on the chromone ring and sulphur group on the pyrimidine ring, was found to exhibit equipotent antifungal activity when compared with the standard drug miconazole. A d-alanine-d-alanine ligase (DdlB enzyme assay study and an ergosterol extraction and quantitation assay study were performed to predict the mode of action of the synthesized compounds. A molecular docking study was performed to predict the binding interactions with receptors and mode of action of the synthesized derivatives. Further, analysis of the ADMET parameters for the synthesized compounds has shown that these compounds have good oral drug-like properties and can be developed as oral drug candidates. To establish the antimicrobial selectivity and safety, the most active compounds 6c and 6f were further tested for cytotoxicity against the human cancer cell line HeLa and were found to be non-cytotoxic in nature. An in vivo acute oral toxicity study was also performed for the most active compounds 6c and 6f and the results indicated that the compounds are non-toxic in nature.

Toxcast Profiling in a Human Stem Cell Assay for Developmental Toxicity (SOT)

Science.gov (United States)

We correlated the ToxCast library in a metabolic biomarker-based in vitro assay (Stemina devTOXqP) utilizing human embryonic stem (hES) cells (H9 line). This assay identifies the concentration of a chemical that disrupts cellular metabolism in a manner indicative of teratogenic...

Innovative Applications of In Situ Gamma Spectroscopy for Non-destructive Assay of Transuranic Wastes

International Nuclear Information System (INIS)

Watters, D.J.; Weismann, J.J.; Duke, S.J.; Nicosia, W.C.

2009-01-01

Cabrera Services (CABRERA), under contract to National Security Technologies, LLC (NSTec), supported the transuranic (TRU) waste reduction initiative at the Radioactive Waste Management Complex of the Nevada Test Site (NTS). CABRERA developed advanced NDA techniques for oversized boxes (OSB) and drums using in situ gamma spectroscopy during several phases of the project. A more thorough characterization method was employed during the planning phase of the project to better understand the TRU content and distribution within each container, while a comprehensive NDA program was designed and implemented during the intrusive phase that guided waste segregation and re-packaging of both TRU and low-level wastes (LLW). NSTec took receipt of 58 oversized boxes of suspect TRU waste from Lawrence Livermore National Lab (LLNL). TRU waste is defined as greater than 3.7 kilobecquerels per gram [kBq/g] (100 nanocuries (nCi)/g) activity from alpha-emitting radionuclides with atomic number greater than 92 having a half-life greater than 20 years. Each box was custom-made to house a variety of suspect TRU wastes resulting from years of weapons program research, development, and testing. Since their arrival at NTS, the boxes have undergone several iterations of non-destructive assay (NDA) in preparation for the comprehensive repackaging effort. NDA has included two rounds of in situ gamma spectroscopy and real-time radiography (RTR) scans that were videotaped. Contents have been confirmed to include glove boxes, HEPA filters and their housings, and assorted process equipment and piping. TRU content was determined via directly measuring plutonium-239 (Pu-239), americium-241 (Am-241), and other radionuclides, while adding calculated results for non-measurable nuclides using reliable scaling factors developed from acceptable knowledge (AK). Advantages of CABRERA's NDA methods included: - More NDA information is available in the same amount of counting time, allowing NSTec to make more

Bioelectrochemical biosensor for water toxicity detection: generation of dual signals for electrochemical assay confirmation.

Science.gov (United States)

Yang, Yuan; Wang, Yan-Zhai; Fang, Zhen; Yu, Yang-Yang; Yong, Yang-Chun

2018-02-01

Toxicity assessment of water is of great important to the safety of human health and to social security because of more and more toxic compounds that are spilled into the aquatic environment. Therefore, the development of fast and reliable toxicity assessment methods is of great interest and attracts much attention. In this study, by using the electrochemical activity of Shewanella oneidensis MR-1 cells as the toxicity indicator, 3,5-dichlorophenol (DCP) as the model toxic compound, a new biosensor for water toxicity assessment was developed. Strikingly, the presence of DCP in the water significantly inhibited the maximum current output of the S. oneidensis MR-1 in a three-electrode system and also retarded the current evolution by the cells. Under the optimized conditions, the maximum current output of the biosensor was proportional to the concentration of DCP up to 30 mg/L. The half maximal inhibitory concentration of DCP determined by this biosensor is about 14.5 mg/L. Furthermore, simultaneous monitoring of the retarded time (Δt) for current generation allowed the identification of another biosensor signal in response to DCP which could be employed to verify the electrochemical result by dual confirmation. Thus, the present study has provided a reliable and promising approach for water quality assessment and risk warning of water toxicity.

Predictive value of cell assays for developmental toxicity and embryotoxicity of conazole fungicides

DEFF Research Database (Denmark)

Sørensen, Karin Dreisig; Taxvig, Camilla; Kjærstad, Mia Birkhøj

2013-01-01

in reasonably good agreement with available in vivo effects. Ketoconazole and epoxiconazole are the most potent embryotoxic compounds, whereas prochloraz belongs to the most potent developmental toxicants. In conclusion, a rough prediction of the ranking of these conazole fungicides for in vivo toxicity data...

Assessment of microplastic toxicity to embryonic development of the sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

Science.gov (United States)

Nobre, C R; Santana, M F M; Maluf, A; Cortez, F S; Cesar, A; Pereira, C D S; Turra, A

2015-03-15

Apart from the physiological impacts on marine organisms caused by ingesting microplastics, the toxicity caused by substances leaching from these particles into the environment requires investigation. To understand this potential risk, we evaluated the toxicity of virgin (raw) and beach-stranded plastic pellets to the development of embryos of Lytechinus variegatus, simulating transfers of chemical compounds to interstitial water and water column by assays of pellet-water interface and elutriate, respectively. Both assays showed that virgin pellets had toxic effects, increasing anomalous embryonic development by 58.1% and 66.5%, respectively. The toxicity of stranded pellets was lower than virgin pellets, and was observed only for pellet-water interface assay. These results show that (i) plastic pellets act as a vector of pollutants, especially for plastic additives found on virgin particles; and that (ii) the toxicity of leached chemicals from pellets depends on the exposure pathway and on the environmental compartment in which pellets accumulate. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cellular toxicity and bioaccumulationof silver nanoparticles in the marine polychaete, Nereis diversicolor

DEFF Research Database (Denmark)

cong, Yi; Banta, Gary Thomas; Selck, Henriette

(comet assay) and bioaccumulation as endpoints. Prior to the toxicity experiment, the physical-chemical properties of Ag NPs were fully characterized. The nominal concentrations used in all exposure scenarios were 0, 5, 10, 25, 50 and 100 µg Ag/g dry weight (dw) sediment. Lysosomal membrane stability...... of Nereis coelomocytes, which was measured by neutral red retention time (NRRT), decreased in a concentration-dependent manner in all Ag treatments, indicating increased permeability of lysosomal membranes. Comet assay results showed that Ag was able to cause DNA damage in Nereis coelomocytes regardless......In this study, the toxicities of commercial silver nanoparticles (Ag NPs, 20 and 80 nm) were compared with the toxicities of Ag+ ions in the marine sediment-dwelling polychaete, Nereis diversicolor, after 10 d of sediment exposure, using lysosomal membrane stability (neutral red assay), DNA damage...

Toxicity and antinociceptive effects of Hamelia patens

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Angel Josabad Alonso-Castro

Full Text Available Abstract Many medicinal herbs are used in folk medicine without taking into account their toxicity. Hamelia patens Jacq. (Rubiaceae, a Mexican endemic species, is used for the empirical treatment of pain. The aim of this work was to evaluate the toxicity and antinociceptive effects of ethanolic extracts of H. patens leaves. The toxicity of H. patens leaves (500–5000 mg/kg was evaluated in acute (14 days and subacute (28 days assays. In the subacute assay, a blood analysis (both hematology and chemistry was carried out. The antinociceptive effects of H. patens leaves (50–200 mg/kg were evaluated using thermal-induced nociception (hot plate and the chemical-induced nociceptive tests (acid acetic and formalin. In the acute toxicity test, the LD50 estimated for H. patens leaves was 2964 mg/kg i.p. and >5000 mg/kg p.o., whereas in the subacute test HPE did not affect hematological or biochemical parameters. In chemical-induced nociception models, H. patens (100 and 200 mg/kg p.o. showed antinociceptive effects with similar activity than 100 mg/kg naproxen. In the hot plate test, HPE at 100 mg/kg (17% and 200 mg/kg (25% showed moderate antinociceptive effects. HPE could be a good source of antinociceptive agents because of its good activity and low toxicity.

Immunotoxicity, genotoxicity and epigenetic toxicity of nanomaterials: New strategies for toxicity testing?

Science.gov (United States)

Dusinska, Maria; Tulinska, Jana; El Yamani, Naouale; Kuricova, Miroslava; Liskova, Aurelia; Rollerova, Eva; Rundén-Pran, Elise; Smolkova, Bozena

2017-11-01

The unique properties of nanomaterials (NMs) are beneficial in numerous industrial and medical applications. However, they could also induce unintended effects. Thus, a proper strategy for toxicity testing is essential in human hazard and risk assessment. Toxicity can be tested in vivo and in vitro; in compliance with the 3Rs, alternative strategies for in vitro testing should be further developed for NMs. Robust, standardized methods are of great importance in nanotoxicology, with comprehensive material characterization and uptake as an integral part of the testing strategy. Oxidative stress has been shown to be an underlying mechanism of possible toxicity of NMs, causing both immunotoxicity and genotoxicity. For testing NMs in vitro, a battery of tests should be performed on cells of human origin, either cell lines or primary cells, in conditions as close as possible to an in vivo situation. Novel toxicity pathways, particularly epigenetic modification, should be assessed along with conventional toxicity testing methods. However, to initiate epigenetic toxicity screens for NM exposure, there is a need to better understand their adverse effects on the epigenome, to identify robust and reproducible causal links between exposure, epigenetic changes and adverse phenotypic endpoints, and to develop improved assays to monitor epigenetic toxicity. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.

Science.gov (United States)

Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M

2014-09-01

Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions. © 2014 SETAC.

In vitro toxicities of experimental jet fuel system ice-inhibiting agents.

Science.gov (United States)

Geiss, K T; Frazier, J M

2001-07-02

One research emphasis within the Department of Defense has been to seek the replacement of operational compounds with alternatives that pose less potential risk to human and ecological systems. Alternatives to glycol ethers, such as diethylene glycol monomethyl ether (M-DE), were investigated for use as jet fuel system ice-inhibiting agents (FSIIs). This group of chemicals includes three derivatives of 1,3-dioxolane-4-methanol (M-1, M-2, and M-3) and a 1,3-dioxane (M-27). In addition, M-DE was evaluated as a reference compound. Our approach was to implement an in vitro test battery based on primary rat hepatocyte cultures to perform initial toxicity evaluations. Hepatocytes were exposed to experimental chemicals (0, 0.001, 0.01, 0.1, 1, 10 mM dosages) for periods up to 24 h. Samples were assayed for lactate dehydrogenase (LDH) release, MTT dye reduction activity, glutathione level, and rate of protein synthesis as indicators of toxicity. Of the compounds tested, M-1, especially at the 10-mM dose, appeared to be more potent than the other chemicals, as measured by these toxicity assays. M-DE, the current FSII, elicited little response in the toxicity assays. Although some variations in toxicity were observed at the 10-mM dose, the in vitro toxicities of the chemicals tested (except for M-1) were not considerably greater than that of M-DE.

Sacha Inchi (Plukenetia volubilis L. powder: acute toxicity, 90 days oral toxicity study and micronucleus assay in rodents

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Idania Rodeiro

2018-02-01

Full Text Available Context: Sacha Inchi has been consumed for years by indigenous peoples. Meanwhile, its toxicological potential has not been sufficiently studied. Aims: To assess the acute, sub-chronic toxicity and genotoxicity evaluation of Sacha Inchi powder obtained from Plukenetia volubilis L. Methods: A dose of 2000 mg/kg was orally administered to rats and mice and toxicity symptoms for 14 days were observed. In repeated dose study, the product was orally administered to Sprague Dawley rats of both sexes. Animals received 50, 250 and 500 mg/kg/day of the product for 90 days. At the end, animals were sacrificed and samples were done for hematological and biochemical analysis, organ weighs and histopathological examination. Genotoxicity potential of Sacha Inchi powder was evaluated through micronucleus test in mice. Negative controls received the vehicle (carboxymethyl cellulose, 0.5% used. Results: No morbidity or mortality at 2000 mg/kg of the product were found. Sacha Inchi powder oral administration during 90 days to rats did not lead to death, body weight gain, food consumption, or adverse events. No significant changes on hematological or biochemical parameters, organ weights or histopathological findings were observed. Induction of micronucleus formation attributable to the product was not found in mice. Conclusions: No toxicity effects after oral acute exposure of Sacha Inchi power to rats and mice were observed. Neither toxicity attributable to oral doses of the product up to 500 mg/kg during 90 days to rats were found. Results suggested Sacha Inchi powder does not have genotoxicity potential under our experimental conditions.

Toxicity of sediment pore water associated with offshore oil and gas platforms in the Gulf of Mexico

International Nuclear Information System (INIS)

Carr, R.S.; Chapman, D.C.

1993-01-01

As a part of a multidisciplinary program to assess the long-term impacts of offshore petroleum production in the Gulf of Mexico, a series of sediment porewater toxicity tests were conducted. Sediments were samples from five petroleum production platforms along five radial transects. Pore water was extracted from the sediment using a pressure extraction device, centrifuged, and frozen for later toxicity testing and chemical analysis. The sea urchin (Arbacia punctulata) embryological development assay and fertilization assay were used to assess porewater toxicity. Significant decreases in normal development of embryos was observed at 14 stations and fertilization was reduced at three stations. All stations with reduced fertilization also showed impaired development in the embryological development assay. All but three toxic sites were within 150 m of the platform. The six most toxic stations were at one platform near the Flower Garden reef, occurring near the platform along three radii; toxicity was always greater at the first site on a radium than at the second. Toxicity is discussed in relation to metal and hydrocarbon concentrations in whole sediment and in pore water

Reducing the cytotoxicity of inhalable engineered nanoparticles via in situ passivation with biocompatible materials

International Nuclear Information System (INIS)

Byeon, Jeong Hoon; Park, Jae Hong; Peters, Thomas M.; Roberts, Jeffrey T.

2015-01-01

Highlights: • The cytotoxicity of model welding particles was modulated through in situ passivation. • Model welding particles were incorporated with chitosan nanoparticles for passivation. • In vitro assay revealed that the passivated particles had a lower cytotoxicity. • Passivation with chitosan adhesive or graphite paste could also reduce cytotoxicity. • This method would be suitable for efficient reduction of inhalable toxic components. - Abstract: The cytotoxicity of model welding nanoparticles was modulated through in situ passivation with soluble biocompatible materials. A passivation process consisting of a spark discharge particle generator coupled to a collison atomizer as a co-flow or counter-flow configuration was used to incorporate the model nanoparticles with chitosan. The tested model welding nanoparticles are inhaled and that A549 cells are a human lung epithelial cell line. Measurements of in vitro cytotoxicity in A549 cells revealed that the passivated nanoparticles had a lower cytotoxicity (>65% in average cell viability, counter-flow) than the untreated model nanoparticles. Moreover, the co-flow incorporation between the nanoparticles and chitosan induced passivation of the nanoparticles, and the average cell viability increased by >80% compared to the model welding nanoparticles. As a more convenient way (additional chitosan generation and incorporation devices may not be required), other passivation strategies through a modification of the welding rod with chitosan adhesive and graphite paste did also enhance average cell viability (>58%). The approach outlined in this work is potentially generalizable as a new platform, using only biocompatible materials in situ, to treat nanoparticles before they are inhaled

Reducing the cytotoxicity of inhalable engineered nanoparticles via in situ passivation with biocompatible materials

Energy Technology Data Exchange (ETDEWEB)

Byeon, Jeong Hoon, E-mail: postjb@yu.ac.kr [School of Mechanical Engineering, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Park, Jae Hong; Peters, Thomas M. [Department of Occupational and Environmental Health, University of Iowa, IA 52242 (United States); Roberts, Jeffrey T., E-mail: jtrob@purdue.edu [Department of Chemistry, Purdue University, IN 47907 (United States)

2015-07-15

Highlights: • The cytotoxicity of model welding particles was modulated through in situ passivation. • Model welding particles were incorporated with chitosan nanoparticles for passivation. • In vitro assay revealed that the passivated particles had a lower cytotoxicity. • Passivation with chitosan adhesive or graphite paste could also reduce cytotoxicity. • This method would be suitable for efficient reduction of inhalable toxic components. - Abstract: The cytotoxicity of model welding nanoparticles was modulated through in situ passivation with soluble biocompatible materials. A passivation process consisting of a spark discharge particle generator coupled to a collison atomizer as a co-flow or counter-flow configuration was used to incorporate the model nanoparticles with chitosan. The tested model welding nanoparticles are inhaled and that A549 cells are a human lung epithelial cell line. Measurements of in vitro cytotoxicity in A549 cells revealed that the passivated nanoparticles had a lower cytotoxicity (>65% in average cell viability, counter-flow) than the untreated model nanoparticles. Moreover, the co-flow incorporation between the nanoparticles and chitosan induced passivation of the nanoparticles, and the average cell viability increased by >80% compared to the model welding nanoparticles. As a more convenient way (additional chitosan generation and incorporation devices may not be required), other passivation strategies through a modification of the welding rod with chitosan adhesive and graphite paste did also enhance average cell viability (>58%). The approach outlined in this work is potentially generalizable as a new platform, using only biocompatible materials in situ, to treat nanoparticles before they are inhaled.

The Comet Assay: Tails of the (Unexpected. Use of the comet assay in pharmaceutical development.

Directory of Open Access Journals (Sweden)

Bas-jan Van Der Leede

2015-08-01

Full Text Available In genotoxicity testing of pharmaceuticals the rodent alkaline comet assay is being increasingly used as a second in vivo assay in addition to the in vivo micronucleus assay to mitigate in vitro positive results as recommended by regulatory guidance. In this presentation we want to give insight into the circumstances in vivo comet assay is deployed in a Genetic Toxicology Department of a pharmaceutical company. As the in vivo comet assay is a salvage assay, it means that some events have occurred in an in vitro assay and that the compound (or metabolite responsible for this signal is potentially deselected for further development. More than often the decision to perform an in vivo comet assay is at a very early stage in development and the first time that the compound will be tested in vivo at high/toxic dose levels. As almost no toxicokinetic data and tissue distribution data are available a careful design with maximizes the chances for successful mitigation is necessary. Decisions on acute or repeated dosing need to be made and arrangements for combining the in vivo comet assay with the in vivo micronucleus assay are to be considered. Often synthesis methods need to be scaled up fast to provide the required amount of compound and information on suitable formulations needs to be in place. As exposure data is crucial for interpretation of results, analytical methods need to be brought in place rapidly. An experienced multi skilled and communicative team needs to be available to deploy successfully this kind of assays at an early stage of development. We will present a few scenarios on study conduct and demonstrate how this assay can make a difference for the further development of a new drug.

Environmental toxicants cause sperm DNA fragmentation as detected by the Sperm Chromatin Structure Assay (SCSA[reg])

International Nuclear Information System (INIS)

Evenson, Donald P.; Wixon, Regina

2005-01-01

Studies over the past two decades have clearly shown that reproductive toxicants cause sperm DNA fragmentation. This DNA fragmentation can usually be detected prior to observing alterations of metaphase chromosomes in embryos. Thus, Sperm Chromatin Structure Assay (SCSA)-detected DNA damage is viewed as the molecular precursor to later gross chromosome damage observed under the light microscope. SCSA measurements of animal or human sperm consist of first obtaining a fresh or flash frozen neat semen sample in LN2 or dry ice. Samples are then sent to a SCSA diagnostic laboratory where the samples are thawed, diluted to ∼1-2 x 106 sperm/ml, treated for 30 s with a pH 1.2 detergent buffer and then stained with acridine orange (AO). The low pH partially denatures DNA at the sites of DNA strand breaks and the AO-ssDNA fluoresces red while the AO-dsDNA fluoresces green. Flow cytometry measurements of 5000 sperm/sample provide statistically robust data on the ratio of red to green sperm, the extent of the DNA fragmentation and the standard deviations of measures. Numerous experiments on rodents treated with reproductive toxicants clearly showed that SCSA measures are highly dose responsive and have a very low CV. Different agents that act on germ cells at various stages of development usually showed sperm DNA fragmentation when that germ cell fraction arrived in the epididymis or ejaculate. Some of these treated samples were capable of successful in vitro fertilization but with frequent embryo failure. A 2-year longitudinal study of men living a valley town with a reported abnormal level of infertility and spontaneous miscarriages and also a seasonal atmospheric smog pollution, showed, for the first time, that SCSA measurements of human sperm DNA fragmentation were detectable and correlated with dosage of air pollution while the classical semen measures were not correlated. Also, young men spraying pesticides without protective gear are at an increased risk for elevated

Toxicity ranking and toxic mode of action evaluation of commonly used agricultural adjuvants on the basis of bacterial gene expression profiles.

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Ingrid Nobels

Full Text Available The omnipresent group of pesticide adjuvants are often referred to as "inert" ingredients, a rather misleading term since consumers associate this term with "safe". The upcoming new EU regulation concerning the introduction of plant protection products on the market (EC1107/2009 includes for the first time the demand for information on the possible negative effects of not only the active ingredients but also the used adjuvants. This new regulation requires basic toxicological information that allows decisions on the use/ban or preference of use of available adjuvants. In this study we obtained toxicological relevant information through a multiple endpoint reporter assay for a broad selection of commonly used adjuvants including several solvents (e.g. isophorone and non-ionic surfactants (e.g. ethoxylated alcohols. The used assay allows the toxicity screening in a mechanistic way, with direct measurement of specific toxicological responses (e.g. oxidative stress, DNA damage, membrane damage and general cell lesions. The results show that the selected solvents are less toxic than the surfactants, suggesting that solvents may have a preference of use, but further research on more compounds is needed to confirm this observation. The gene expression profiles of the selected surfactants reveal that a phenol (ethoxylated tristyrylphenol and an organosilicone surfactant (ethoxylated trisiloxane show little or no inductions at EC(20 concentrations, making them preferred surfactants for use in different applications. The organosilicone surfactant shows little or no toxicity and good adjuvant properties. However, this study also illustrates possible genotoxicity (induction of the bacterial SOS response for several surfactants (POEA, AE, tri-EO, EO FA and EO NP and one solvent (gamma-butyrolactone. Although the number of compounds that were evaluated is rather limited (13, the results show that the used reporter assay is a promising tool to rank commonly

Acute toxicity and bio-accumulation of mercury and copper in ...

African Journals Online (AJOL)

The acute toxicity of Mercury and Copper on C. africanus and T. fuscatus and the bio-accumulation potentials of the metals were investigated in laboratory experiments employing standard bio–assay techniques. On the basis of LC50 values, both metals had similar magnitudes of toxicity against C. africanus. However ...

Succinate Dehydrogenase Activity Assay in situ with Blue Tetrazolium Salt in Crabtree-Positive Saccharomyces cerevisiae Strain

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Joanna Berlowska

2008-01-01

Full Text Available A spectrophotometric method for determining succinate dehydrogenase (SDH activity assay in azide-sensitive yeast Saccharomyces cerevisiae has been developed. The permeabilization of yeast cells by 0.05 % digitonin permitted to study yeast enzymatic activity in situ. The reduction of blue tetrazolium salt (BT to blue tetrazolium formazan (BTf was conducted in the presence of phenazine methosulphate (PMS as an exogenous electron carrier, and sodium azide (SA as an inhibitor of cytochrome oxidase (Cyt pathway. Various factors such as type of substrate, BT concentration, cell number, temperature and time of incubation, and different Cyt pathway blockers were optimized. In earlier studies, dimethyl sulfoxide (DMSO had been selected as the best solvent for extraction of BTf from yeast cells. The linear correlation between permeabilized yeast cell density and amount of formed formazan was evidenced in the range from 9·10^7 to 5·10^8 cells per sample solution. Below the yeast cell concentration of 10^7 the absorbance values were too low to detect formazans with good precision. This standarized procedure allows the estimation of SDH activity in whole cells, depending on vitality level of yeast populations. Significant increases of succinate dehydrogenase activities were observed in sequential passages as the result of the increase of activity of the strain and adaptation to cultivation conditions.

Vectorization by nanoparticles decreases the overall toxicity of airborne pollutants.

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Rodolphe Carpentier

Full Text Available Atmospheric pollution is mainly composed of volatile pollutants and particulate matter that strongly interact. However, their specific roles in the induction of cellular toxicity, in particular the impact of the vectorization of atmospheric pollutants by ultrafine particles, remains to be fully elucidated. For this purpose, non-toxic poly-lactic co-glycolic acid (PLGA nanoparticles were synthesized and three pollutants (benzo(apyrene, naphthalene and di-ethyl-hexyl-phthalate were adsorbed on the surface of the nanoparticles in order to evaluate the toxicity (cytotoxicity, genotoxicity and ROS induction of these complexes to a human airway epithelial cell line. The adsorption of the pollutants onto the nanoparticles was confirmed by HPLC analysis. Interestingly, the cytotoxicity assays (MTT, LDH and CellTox Green clearly demonstrated that the vectorization by nanoparticles decreases the toxicity of the adsorbed pollutants. Genotoxicity was assessed by the micronucleus test and the comet assay and showed no increase in primary DNA damage or in chromosomal aberrations of nanoparticle vectorized pollutants. Neither cytotoxicity nor genotoxicity was correlated with ROS induction. To conclude, our results indicate that the vectorization of pollutants by nanoparticles does not potentiate the toxicity of the pollutants studied and that, on the contrary, adsorption onto nanoparticles could protect cells against pollutants' toxicity.

Vectorization by nanoparticles decreases the overall toxicity of airborne pollutants.

Science.gov (United States)

Carpentier, Rodolphe; Platel, Anne; Maiz-Gregores, Helena; Nesslany, Fabrice; Betbeder, Didier

2017-01-01

Atmospheric pollution is mainly composed of volatile pollutants and particulate matter that strongly interact. However, their specific roles in the induction of cellular toxicity, in particular the impact of the vectorization of atmospheric pollutants by ultrafine particles, remains to be fully elucidated. For this purpose, non-toxic poly-lactic co-glycolic acid (PLGA) nanoparticles were synthesized and three pollutants (benzo(a)pyrene, naphthalene and di-ethyl-hexyl-phthalate) were adsorbed on the surface of the nanoparticles in order to evaluate the toxicity (cytotoxicity, genotoxicity and ROS induction) of these complexes to a human airway epithelial cell line. The adsorption of the pollutants onto the nanoparticles was confirmed by HPLC analysis. Interestingly, the cytotoxicity assays (MTT, LDH and CellTox Green) clearly demonstrated that the vectorization by nanoparticles decreases the toxicity of the adsorbed pollutants. Genotoxicity was assessed by the micronucleus test and the comet assay and showed no increase in primary DNA damage or in chromosomal aberrations of nanoparticle vectorized pollutants. Neither cytotoxicity nor genotoxicity was correlated with ROS induction. To conclude, our results indicate that the vectorization of pollutants by nanoparticles does not potentiate the toxicity of the pollutants studied and that, on the contrary, adsorption onto nanoparticles could protect cells against pollutants' toxicity.

A vast collection of microbial genes that are toxic to bacteria

Energy Technology Data Exchange (ETDEWEB)

Kimelman, Aya; Levy, Asaf; Sberro, Hila; Kidron, Shahar; Leavitt, Azita; Amitai, Gil; Yoder-Himes, Deborah; Wurtzel, Omri; Zhu, Yiwen; Rubin, Edward M; Sorek, Rotem

2012-02-02

In the process of clone-based genome sequencing, initial assemblies frequently contain cloning gaps that can be resolved using cloning-independent methods, but the reason for their occurrence is largely unknown. By analyzing 9,328,693 sequencing clones from 393 microbial genomes we systematically mapped more than 15,000 genes residing in cloning gaps and experimentally showed that their expression products are toxic to the Escherichia coli host. A subset of these toxic sequences was further evaluated through a series of functional assays exploring the mechanisms of their toxicity. Among these genes our assays revealed novel toxins and restriction enzymes, and new classes of small non-coding toxic RNAs that reproducibly inhibit E. coli growth. Further analyses also revealed abundant, short toxic DNA fragments that were predicted to suppress E. coli growth by interacting with the replication initiator dnaA. Our results show that cloning gaps, once considered the result of technical problems, actually serve as a rich source for the discovery of biotechnologically valuable functions, and suggest new modes of antimicrobial interventions.

Hazard evaluation of soil contaminants from an abandoned oil refinery site with chemical and biological assays

International Nuclear Information System (INIS)

Ramanathan, A.; Yates, C.W.; Burks, S.L.

1993-01-01

The phytotoxic characteristics of soil and leachates of soil from an abandoned oil refinery site were evaluated with rice (Oryza sativa L.) seed germinations and root elongation assays. Toxicity of soil leachates to aquatic animals was determined with acute and martial chronic toxicity tests with Ceriodaphnia dubia, fathead minnows, and Microtox reg-sign. Soil samples from uncontaminated (control) and selected contaminated areas within the old refinery were extracted with Toxic Characteristics Leachate Procedure (TCLP), an aqueous procedure and a supercritical carbon dioxide method. Aqueous extracts of soil from the oil leaded gasoline storage area exhibited greatest effects in all tests. Aqueous extracts from this site also caused a significant reduction in rice root development. Supercritical carbon dioxide extraction proved to be a quick and non-toxic procedure for isolating non-polar organics for assay with aquatic toxicity tests. Subsequent supercritical extracts collected in solvent can help characterize the class of toxicants through HPLC and Gas Chromatography. The toxic constituents were characterized with a Toxicity Identification/Toxicity Reduction Evaluation protocol to fractionate the contaminants into conventional non-polar organics, weak acids, base-neutrals, or heavy metals for subsequent analysis

Fish eco-genotoxicology: Comet and micronucleus assay in fish erythrocytes as in situ biomarker of freshwater pollution

Directory of Open Access Journals (Sweden)

Bilal Hussain

2018-02-01

Full Text Available Owing to white meat production Labeo rohita have vast economic importance, but its population has been reduced drastically in River Chenab due to pollution. Atomic absorption spectrophotometry showed a merciless toxicity level of Cd, Cu, Mn, Zn, Pb, Cr, Sn and Hg. Comet assay results indicated significant (p < .05 DNA fragmentation in Labeo rohita as 42.21 ± 2.06%, 31.26 ± 2.41% and 21.84 ± 2.21% DNA in comet tail, tail moment as 17.71 ± 1.79, 10.30 ± 1.78 and 7.81 ± 1.56, olive moment as 13.58 ± 1.306, 8.10 ± 1.04 and 5.88 ± 0.06, respectively, from three different polluted sites on the river. Micronucleus assay showed similar findings of single micronucleus induction (MN as 50.00 ± 6.30‰, double MN 14.40 ± 2.56‰, while nuclear abnormalities (NA were found as 150.00 ± 2.92‰. These higher frequencies of MN induction and NA were found to be the cause of reduction of 96% of the population of this fish species in an experimental area of the River Chenab. This fish species has been found near extinction through the length of the river Chenab and few specimens in rainy seasons if restored by flood, may die in sugarcane mill season. Due to sweeping extinction Labeo rohita showed the highest sensitivity for pollution and could be used as bioindicator and DNA fragmentation in this column feeder fish species as a biomarker of the pollution load in freshwater bodies.

Alkaline comet assay in liver and stomach, and micronucleus assay in bone marrow, from rats treated with 2-acetylaminofluorene, azidothymidine, cisplatin, or isobutyraldehyde.

Science.gov (United States)

Kraynak, A R; Barnum, J E; Cunningham, C L; Ng, A; Ykoruk, B A; Bennet, B; Stoffregen, D; Merschman, M; Freeland, E; Galloway, S M

2015-07-01

As part of the Japanese Center for the Validation of Alternative Methods (JaCVAM) initiative international validation study of the in vivo rat alkaline comet assay (comet assay), we examined the ability of the assay to determine the genotoxicity of 2-acetylaminofluorene (AAF), azidothymidine (AZT), cisplatin (CPN), and isobutyraldehyde (IBA) in liver and glandular stomach of male Sprague-Dawley rats. Rats were given oral doses of test compound or control once daily for three days. High dose levels were approximately maximum tolerated doses and were based on preliminary range-finding studies. Tissues were harvested 3h after the final dose (48h after the initial dose). A bone marrow micronucleus assay (MN) was also conducted on the rats treated with AZT, CPN, and IBA. Acute toxic effects of treatment were determined primarily through histomorphologic analysis of liver and stomach but also by body weight and serum liver enzyme changes. The comet assay was conducted on fresh tissue preparations but frozen samples from two studies were also assayed. Statistically significant dose-related differences in comet % DNA in tail were found in liver and stomach for the genotoxin AZT and in liver for the genotoxin CPN, but not in liver or stomach for the non-genotoxin IBA. Statistically significant differences in % DNA in tail were measured in liver for the low and mid dose of the genotoxin AAF, but not the high dose. The comet assays of frozen liver suspensions from CPN- and AAF-treated rats yielded comparable results to the assays of fresh preparations. There were no indications of significant toxicity induced by any treatment. The micronucleus assay was positive for CPN and AZT and negative for IBA. In conclusion, the in vivo comet assay is capable of detecting genotoxic effects of a variety of chemicals and may fill an important role in the genotoxicity test battery. Copyright © 2015 Elsevier B.V. All rights reserved.

Toxicity of nonylphenol diethoxylate in lab-scale anaerobic digesters

DEFF Research Database (Denmark)

Bozkurt, Hande; Sanin, F. Dilek

2014-01-01

Nonylphenol compounds have high commercial, industrial and domestic uses owing to their surface active properties. In addition to their toxic, carcinogenic and persistent characteristics; they have drawn the attention of scientists lately due to their endocrine disrupting properties....... Their widespread use and disposal cause them to enter wastewater treatment systems at high concentrations. Since they are highly persistent and hydrophobic, they accumulate mostly on sludge.In this study using Anaerobic Toxicity Assay (ATA) tests, the toxicity of a model nonylphenol compound, nonylphenol...

Gene protein detection platform--a comparison of a new human epidermal growth factor receptor 2 assay with conventional immunohistochemistry and fluorescence in situ hybridization platforms.

Science.gov (United States)

Stålhammar, Gustav; Farrajota, Pedro; Olsson, Ann; Silva, Cristina; Hartman, Johan; Elmberger, Göran

2015-08-01

Human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are widely used semiquantitative assays for selecting breast cancer patients for HER2 antibody therapy. However, both techniques have been shown to have disadvantages. Our aim was to test a recent automated technique of combined IHC and brightfield dual in situ hybridization-gene protein detection platform (GPDP)-in breast cancer HER2 protein, gene, and chromosome 17 centromere status evaluations, comparing the results in accordance to the American Society of Clinical Oncology/College of American Pathologists recommendations for HER2 testing in breast cancer from both 2007 and 2013. The GPDP technique performance was evaluated on 52 consecutive whole slide invasive breast cancer cases with HER2 IHC 2/3+ scoring results. Applying in turns the American Society of Clinical Oncology/College of American Pathologists recommendations for HER2 testing in breast cancer from 2007 and 2013 to both FISH and GPDP DISH assays, the HER2 gene amplification results showed 100% concordance among amplified/nonamplified cases, but there was a shift in 4 cases toward positive from equivocal results and toward equivocal from negative results. This might be related to the emphasis on the average HER2 copy number in the 2013 criteria. HER2 expression by IVD market IHC kit (Pathway®) has a strong correlation with GPDP HER2 protein, including a full concordance for all cases scored as 3+ and a reduction from 2+ to 1+ in 7 cases corresponding to nonamplified cases. Gene protein detection platform HER2 protein "solo" could have spared the need for 7 FISH studies. In addition, the platform offered advantages on interpretation reassurance including selecting areas for counting gene signals paralleled with protein IHC expression, on heterogeneity detection, interpretation time, technical time, and tissue expense. Copyright © 2015 Elsevier Inc. All rights reserved.

Assessing protein oxidation by inorganic nanoparticles with enzyme-linked immunosorbent assay (ELISA).

Science.gov (United States)

Sun, Wenjie; Luna-Velasco, Antonia; Sierra-Alvarez, Reyes; Field, Jim A

2013-03-01

Growth in the nanotechnology industry is leading to increased production of engineered nanoparticles (NPs). This has given rise to concerns about the potential adverse and toxic effects to biological system and the environment. An important mechanism of NP toxicity is oxidative stress caused by the formation of reactive oxygen species (ROS) or via direct oxidation of biomolecules. In this study, a protein oxidation assay was developed as an indicator of biomolecule oxidation by NPs. The oxidation of the protein, bovine serum albumin (BSA) was evaluated with an enzyme-linked immunosorbent assay (ELISA) to measure the protein carbonyl derivatives formed from protein oxidation. The results showed that some NPs such as Cu(0), CuO, Mn(2)O(3), and Fe(0) caused oxidation of BSA; whereas, many of the other NPs tested were not reactive or very slowly reactive with BSA. The mechanisms involved in the oxidation of BSA protein by the reactive NPs could be attributed to the combined effects of ROS-dependent and direct protein oxidation mechanisms. The ELISA assay is a promising method for the assessment of protein oxidation by NPs, which can provide insights on NP toxicity mechanisms. Copyright © 2012 Wiley Periodicals, Inc.

Oxidative Stress and Nano-Toxicity Induced by TiO2 and ZnO on WAG Cell Line.

Directory of Open Access Journals (Sweden)

Akhilesh Dubey

Full Text Available Metallic nanoparticles are widely used in cosmetics, food products and textile industry. These particles are known to cause respiratory toxicity and epithelial inflammation. They are eventually released to aquatic environment necessitating toxicity studies in cells from respiratory organs of aquatic organisms. Hence, we have developed and characterized a new cell line, WAG, from gill tissue of Wallago attu for toxicity assessment of TiO2 and ZnO nanoparticles. The efficacy of the cell line as an in vitro system for nanoparticles toxicity studies was established using electron microscopy, cytotoxicity assays, genotoxicity assays and oxidative stress biomarkers. Results obtained with MTT assay, neutral red uptake assay and lactate dehydrogenase assay showed acute toxicity to WAG cells with IC50 values of 25.29 ± 0.12, 34.99 ± 0.09 and 35.06 ± 0.09 mg/l for TiO2 and 5.716 ± 0.1, 3.160 ± 0.1 and 5.57 ± 0.12 mg/l for ZnO treatment respectively. The physicochemical properties and size distribution of nanoparticles were characterized using electron microscopy with integrated energy dispersive X-ray spectroscopy and Zetasizer. Dose dependent increase in DNA damage, lipid peroxidation and protein carbonylation along with a significant decrease in activity of Superoxide Dismutase, Catalase, total Glutathione levels and total antioxidant capacity with increasing concentration of exposed nanoparticles indicated that the cells were under oxidative stress. The study established WAG cell line as an in vitro system to study toxicity mechanisms of nanoparticles on aquatic organisms.

Use of the microscreen phage-induction assay to assess the genotoxicity of 14 hazardous industrial wastes

Energy Technology Data Exchange (ETDEWEB)

Houk, V.S.; DeMarini, D.M.

1988-01-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s(lambda), was used to test 14 crude (unfractionated) hazardous industrial waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 pg per ml. Comparisons between the ability of these waste samples to induce prophage and their mutagenicity in the Salmonella reverse mutation assay indicate that the phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic five additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed, as are some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

Toxicity profile of labile preservative bronopol in water: The role of more persistent and toxic transformation products

International Nuclear Information System (INIS)

Cui Na; Zhang Xiaoxiang; Xie Qing; Wang Se; Chen Jingwen; Huang Liping; Qiao Xianliang; Li Xuehua; Cai Xiyun

2011-01-01

Transformation products usually differ in environmental behaviors and toxicological properties from the parent contaminants, and probably cause potential risks to the environment. Toxicity evolution of a labile preservative, bronopol, upon primary aquatic degradation processes was investigated. Bronopol rapidly hydrolyzed in natural waters, and primarily produced more stable 2-bromo-2-nitroethanol (BNE) and bromonitromethane (BNM). Light enhanced degradation of the targeted compounds with water site specific photoactivity. The bond order analysis theoretically revealed that the reversible retroaldol reactions were primary degradation routes for bronopol and BNE. Judging from toxicity assays and the relative pesticide toxicity index, these degradation products (i.e., BNE and BNM), more persistent and higher toxic than the parent, probably accumulated in natural waters and resulted in higher or prolonging adverse impacts. Therefore, these transformation products should be included into the assessment of ecological risks of non-persistent and low toxic chemicals such as the preservative bronopol. - The preservative bronopol is non-persistent and low toxic, but some transformation products can cause higher or prolonging adverse impacts.

Toxicity profile of labile preservative bronopol in water: The role of more persistent and toxic transformation products

Energy Technology Data Exchange (ETDEWEB)

Cui Na; Zhang Xiaoxiang; Xie Qing; Wang Se; Chen Jingwen; Huang Liping; Qiao Xianliang; Li Xuehua [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China); Cai Xiyun, E-mail: xiyuncai@dlut.edu.c [Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024 (China)

2011-02-15

Transformation products usually differ in environmental behaviors and toxicological properties from the parent contaminants, and probably cause potential risks to the environment. Toxicity evolution of a labile preservative, bronopol, upon primary aquatic degradation processes was investigated. Bronopol rapidly hydrolyzed in natural waters, and primarily produced more stable 2-bromo-2-nitroethanol (BNE) and bromonitromethane (BNM). Light enhanced degradation of the targeted compounds with water site specific photoactivity. The bond order analysis theoretically revealed that the reversible retroaldol reactions were primary degradation routes for bronopol and BNE. Judging from toxicity assays and the relative pesticide toxicity index, these degradation products (i.e., BNE and BNM), more persistent and higher toxic than the parent, probably accumulated in natural waters and resulted in higher or prolonging adverse impacts. Therefore, these transformation products should be included into the assessment of ecological risks of non-persistent and low toxic chemicals such as the preservative bronopol. - The preservative bronopol is non-persistent and low toxic, but some transformation products can cause higher or prolonging adverse impacts.

Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

Science.gov (United States)

Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

2015-08-01

For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

Ex-Situ Remediation Technologies for Environmental Pollutants: A Critical Perspective.

Science.gov (United States)

Kuppusamy, Saranya; Palanisami, Thavamani; Megharaj, Mallavarapu; Venkateswarlu, Kadiyala; Naidu, Ravi

2016-01-01

Pollution and the global health impacts from toxic environmental pollutants are presently of great concern. At present, more than 100 million people are at risk from exposure to a plethora of toxic organic and inorganic pollutants. This review is an exploration of the ex-situ technologies for cleaning-up the contaminated soil, groundwater and air emissions, highlighting their principles, advantages, deficiencies and the knowledge gaps. Challenges and strategies for removing different types of contaminants, mainly heavy metals and priority organic pollutants, are also described.

Methods of acute biological assays in guinea-pigs for the study of toxicity and innocuity of drugs and chemicals

Directory of Open Access Journals (Sweden)

Gui Mi Ko

2010-06-01

Full Text Available In this study, 602 samples were tested by the following assays performed at the animal facilities (Cedeme of the Federal University of São Paulo (UNIFESP: 385 for dermal irritability, 90 for ocular irritability (discontinued in 1995, 31 for systemic toxicity by injection, 26 for oral acute toxicity, 15 for toxicity by intracutaneous injection, 15 for skin sensitization, 15 for toxicity of serum and vaccines for human use, 14 for toxicity by intramuscular implantation, 7 for pyrogens, 2 for acute dermal toxicity, and 2 for irritation of mucous membrane. The following agents were tested: cosmetics and related substances (42.0%, chemicals used in industry (32.9%, plastics, rubber, and other polymers (15.9%, agrotoxics (4.0%, medicines (2.7%, and vaccines (2.5%. In the present description, emphasis was given to tests of dermal irritability and sensitization. This work was conducted entirely in animal facilities, according to our general belief that animal facilities at universities, while considering ethic principles and sanitary, genetic, nutritional, and pathophysiological controls, also require laboratories specialized in areas such as transgenics, cryopreservation, ambiental physiology, functional genomics, alternative models, and mainly activities and research on methods in toxicology, as focused in this study.Descrevemos os testes usados em ensaios biológicos de curta duração para estudo de toxicidade e inocuidade de cosméticos, fármacos e outras substâncias químicas, feitos no Biotério Central/Cedeme da Unifesp, de 1986 a 2000. Testamos 602 amostras nos seguintes ensaios: 385 de irritação cutânea, 90 de irritação ocular (até 1995, 31 de toxicidade sistêmica por injeção, 26 de toxicidade oral aguda, 15 de toxicidade por aplicação intracutânea, 15 de sensibilização da pele, 15 de toxicidade de soros e vacinas de uso humano, 14 de toxicidade por implantação intramuscular, 7 de pirogênio, 2 de toxicidade dérmica aguda e

Caenorhabditis elegans as a Model for Toxic Effects of Nanoparticles: Lethality, Growth, and Reproduction.

Science.gov (United States)

Maurer, Laura L; Ryde, Ian T; Yang, Xinyu; Meyer, Joel N

2015-11-02

The nematode Caenorhabditis elegans is extensively utilized in toxicity studies. C. elegans offers a high degree of homology with higher organisms, and its ease of use and relatively inexpensive maintenance have made it an attractive complement to mammalian and ecotoxicological models. C. elegans provides multiple benefits, including the opportunity to perform relatively high-throughput assays on whole organisms, a wide range of genetic tools permitting investigation of mechanisms and genetic sensitivity, and transparent bodies that facilitate toxicokinetic studies. This unit describes protocols for three nanotoxicity assays in C. elegans: lethality, growth, and reproduction. This unit focuses on how to use these well-established assays with nanoparticles, which are being produced in ever-increasing volume and exhibit physicochemical properties that require alteration of standard toxicity assays. These assays permit a broad phenotypic assessment of nanotoxicity in C. elegans, and, when used in combination with genetic tools and other assays, also permit mechanistic insight. Copyright © 2015 John Wiley & Sons, Inc.

Recommended Immunological Assays to Screen for Ricin-Containing Samples

Directory of Open Access Journals (Sweden)

Stéphanie Simon

2015-11-01

Full Text Available Ricin, a toxin from the plant Ricinus communis, is one of the most toxic biological agents known. Due to its availability, toxicity, ease of production and absence of curative treatments, ricin has been classified by the Centers for Disease Control and Prevention (CDC as category B biological weapon and it is scheduled as a List 1 compound in the Chemical Weapons Convention. An international proficiency test (PT was conducted to evaluate detection and quantification capabilities of 17 expert laboratories. In this exercise one goal was to analyse the laboratories’ capacity to detect and differentiate ricin and the less toxic, but highly homologuous protein R. communis agglutinin (RCA120. Six analytical strategies are presented in this paper based on immunological assays (four immunoenzymatic assays and two immunochromatographic tests. Using these immunological methods “dangerous” samples containing ricin and/or RCA120 were successfully identified. Based on different antibodies used the detection and quantification of ricin and RCA120 was successful. The ricin PT highlighted the performance of different immunological approaches that are exemplarily recommended for highly sensitive and precise quantification of ricin.

Addressing the selectivity and toxicity of antiviral nucleosides.

Science.gov (United States)

Feng, Joy Y

2018-01-01

Nucleoside and nucleotide analogs have played significant roles in antiviral therapies and are valued for their impressive potency and high barrier to resistance. They have been approved for treatment of herpes simplex virus-1, HIV, HBV, HCV, and influenza, and new drugs are being developed for the treatment of RSV, Ebola, coronavirus MERS, and other emerging viruses. However, this class of compounds has also experienced a high attrition rate in clinical trials due to toxicity. In this review, we discuss the utility of different biochemical and cell-based assays and provide recommendations for assessing toxicity liability before entering animal toxicity studies.

Application of fluorescent in situ hybridisation for demonstration of Coxiella burnetti in placentas from ruminant abortions

DEFF Research Database (Denmark)

Jensen, Tim Kåre; Montgomery, Donald L.; Jaeger, Paula T.

2007-01-01

A fluorescent in situ hybridisation (FISH) assay targeting 16S ribosomal RNA was developed for detection of the zoonotic bacterium Coxiella burnetii in formalin-fixed, paraffin-embedded tissue, and applied on placentas from ruminant abortions. The applicability of the FISH assay was compared...

Whole acute toxicity removal from industrial and domestic effluents treated by electron beam radiation: emphasis on anionic surfactants

International Nuclear Information System (INIS)

Moraes, M.C.F.; Romanelli, M.F; Sena, H.C.; Pasqualini da Silva, G.; Sampa, M.H.O.; Borrely, S.I.

2004-01-01

Electron beam radiation has been applied to improve real industrial and domestic effluents received by Suzano wastewater treatment plant. Radiation efficacy has been evaluated as toxicity reduction, using two biological assays. Three sites were sampled and submitted for toxicity assays, anionic surfactant determination and electron beam irradiation. This paper shows the reduction of acute toxicity for both test-organisms, the marine bacteria Vibrio fischeri and the crustacean Daphnia similis. The raw toxic effluents exibitted from 0.6 ppm up to 11.67 ppm for anionic surfactant before being treated by the electron beam. Radiation processing resulted in reduction of the acute toxicity as well as surfactant removal. The final biological effluent was in general less toxic than other sites but the presence of anionic surfactants was evidenced

Whole acute toxicity removal from industrial and domestic effluents treated by electron beam radiation: emphasis on anionic surfactants

Energy Technology Data Exchange (ETDEWEB)

Moraes, M.C.F. E-mail: mariacristinafm@uol.com.br; Romanelli, M.F; Sena, H.C.; Pasqualini da Silva, G.; Sampa, M.H.O.; Borrely, S.I

2004-10-01

Electron beam radiation has been applied to improve real industrial and domestic effluents received by Suzano wastewater treatment plant. Radiation efficacy has been evaluated as toxicity reduction, using two biological assays. Three sites were sampled and submitted for toxicity assays, anionic surfactant determination and electron beam irradiation. This paper shows the reduction of acute toxicity for both test-organisms, the marine bacteria Vibrio fischeri and the crustacean Daphnia similis. The raw toxic effluents exibitted from 0.6 ppm up to 11.67 ppm for anionic surfactant before being treated by the electron beam. Radiation processing resulted in reduction of the acute toxicity as well as surfactant removal. The final biological effluent was in general less toxic than other sites but the presence of anionic surfactants was evidenced.

Toxic cyanobacteria and cyanotoxins in public hot springs in Saudi Arabia.

Science.gov (United States)

Mohamed, Zakaria A

2008-01-01

Toxic cyanobacteria are well reported in rivers, lakes and even marine environments, but the toxin production of cyanobacteria in hot springs is largely unexplored. Therefore, the present study investigated the presence of toxic cyanobacteria and cyanotoxins in public hot springs in Saudi Arabia. The results of an enzyme-linked immunosorbent assay (ELISA) revealed that Saudi spring cyanobacterial mats contained microcystins (MCYSTs) at concentrations ranging from 468 to 512.5 microg g(-1). The Limulus amebocyte lystae (LAL) assay detected lipopolysaccharide (LPS) endotoxins in these mats at concentrations ranging from 433.3 to 506.8 EU g(-1). MCYSTs and endotoxins were also detected in spring waters at levels of 5.7 microg l(-1) and 640 EU ml(-1), respectively, exceeding WHO's provisional guideline value for MCYST-LR in drinking-water. High-performance liquid chromatography (HPLC) analysis revealed that only Oscillatoria limosa and Synechococcus lividus can produce MCYSTs with a profile consisting of MCYST-RR and -LR. Based on the LAL assay, 12 out of 17 cyanobacterial species contained LPS at concentrations ranging from 0.93 to 21.06 EU g(-1). However, not all LPS of these species were toxic to mice. This study suggests that the hot springs in the world including Saudi Arabia should be screened for toxic cyanobacteria to avoid the exposure of people recreating and bathing in spring waters to cyanobacterial toxins.

Late toxicity in breast cancer radiotherapy

International Nuclear Information System (INIS)

Gonzalez Coletti, F.; Rafailovici, L.; Filomia, M.L.; Chiozza, J.; Dosoretz, B.

2008-01-01

Full text: The aim of this study is to describe and classify chronic complications due to radiotherapy in breast cancer. Also the impact of radiotherapy on the quality of life of patients is evaluated. Materials and methods: 50 patients with breast cancer at early stages (78% in situ, 22% I and II) treated with radiotherapy in breast volume plus boost (45/50 Gy + 18/20 Gy) with a follow up over 5 years. Acute toxicities were found retrospectively and chronic toxicities were assessed though physical examination and review of complementary studies. To facilitate data collection, pre printed forms were used. Bibliographic searches were made. Results: 10% received chemotherapy and 64% tamoxifen. The predominant chronic toxicity were found in skin (66%), although grade I and II (hyperpigmentation 26%, dryness 22%, telangiectasia 10% fibrosis, 4%, other 4%). A 50% of the patients showed hypoesthesia in ipsilateral upper limb. The other toxicities were presented in low rate and magnitude: mastodynia 16%; actinic pneumonitis 4%, pyrosis 4%, Tachycardia 2%, among others. Of the patients with acute toxicity, only 30% were grade III. The 70% of the patients had a positive impact of radiotherapy on quality of life. Conclusions: We found low rates and degrees of late toxicity. It was noticed a relationship between acute and chronic toxicity, because those who presented adverse effects during treatment developed late effects. It reflects the importance of integrating monitoring as part of radiation treatment. It should be adopted a single score of late toxicity measurement to unify data from different series. (authors) [es

GHS additivity formula: can it predict the acute systemic toxicity of agrochemical formulations that contain acutely toxic ingredients?

Science.gov (United States)

Van Cott, Andrew; Hastings, Charles E; Landsiedel, Robert; Kolle, Susanne; Stinchcombe, Stefan

2018-02-01

In vivo acute systemic testing is a regulatory requirement for agrochemical formulations. GHS specifies an alternative computational approach (GHS additivity formula) for calculating the acute toxicity of mixtures. We collected acute systemic toxicity data from formulations that contained one of several acutely-toxic active ingredients. The resulting acute data set includes 210 formulations tested for oral toxicity, 128 formulations tested for inhalation toxicity and 31 formulations tested for dermal toxicity. The GHS additivity formula was applied to each of these formulations and compared with the experimental in vivo result. In the acute oral assay, the GHS additivity formula misclassified 110 formulations using the GHS classification criteria (48% accuracy) and 119 formulations using the USEPA classification criteria (43% accuracy). With acute inhalation, the GHS additivity formula misclassified 50 formulations using the GHS classification criteria (61% accuracy) and 34 formulations using the USEPA classification criteria (73% accuracy). For acute dermal toxicity, the GHS additivity formula misclassified 16 formulations using the GHS classification criteria (48% accuracy) and 20 formulations using the USEPA classification criteria (36% accuracy). This data indicates the acute systemic toxicity of many formulations is not the sum of the ingredients' toxicity (additivity); but rather, ingredients in a formulation can interact to result in lower or higher toxicity than predicted by the GHS additivity formula. Copyright © 2018 Elsevier Inc. All rights reserved.

Mechanism Profiling of Hepatotoxicity Caused by Oxidative Stress Using Antioxidant Response Element Reporter Gene Assay Models and Big Data.

Science.gov (United States)

Kim, Marlene Thai; Huang, Ruili; Sedykh, Alexander; Wang, Wenyi; Xia, Menghang; Zhu, Hao

2016-05-01

Hepatotoxicity accounts for a substantial number of drugs being withdrawn from the market. Using traditional animal models to detect hepatotoxicity is expensive and time-consuming. Alternative in vitro methods, in particular cell-based high-throughput screening (HTS) studies, have provided the research community with a large amount of data from toxicity assays. Among the various assays used to screen potential toxicants is the antioxidant response element beta lactamase reporter gene assay (ARE-bla), which identifies chemicals that have the potential to induce oxidative stress and was used to test > 10,000 compounds from the Tox21 program. The ARE-bla computational model and HTS data from a big data source (PubChem) were used to profile environmental and pharmaceutical compounds with hepatotoxicity data. Quantitative structure-activity relationship (QSAR) models were developed based on ARE-bla data. The models predicted the potential oxidative stress response for known liver toxicants when no ARE-bla data were available. Liver toxicants were used as probe compounds to search PubChem Bioassay and generate a response profile, which contained thousands of bioassays (> 10 million data points). By ranking the in vitro-in vivo correlations (IVIVCs), the most relevant bioassay(s) related to hepatotoxicity were identified. The liver toxicants profile contained the ARE-bla and relevant PubChem assays. Potential toxicophores for well-known toxicants were created by identifying chemical features that existed only in compounds with high IVIVCs. Profiling chemical IVIVCs created an opportunity to fully explore the source-to-outcome continuum of modern experimental toxicology using cheminformatics approaches and big data sources. Kim MT, Huang R, Sedykh A, Wang W, Xia M, Zhu H. 2016. Mechanism profiling of hepatotoxicity caused by oxidative stress using antioxidant response element reporter gene assay models and big data. Environ Health Perspect 124:634-641;�

Use of the Microscreen phage-induction assay to assess the genotoxicity of 14 hazardous industrial wastes

Energy Technology Data Exchange (ETDEWEB)

Houk, V.S.; DeMarini, D.M.

1988-01-01

The Microscreen phage-induction assay, which quantitatively measures the induction of prophage lambda in Escherichia coli WP2s lambda, was used to test 14 crude (unfractionated) hazardous industrial-waste samples for genotoxic activity in the presence and absence of metabolic activation. Eleven of the 14 wastes induced prophage, and induction was observed at concentrations as low as 0.4 picograms per ml. Comparisons between the mutagenicity of these waste samples in Salmonella and their ability to induce prophage lambda indicate that the Microscreen phage-induction assay detected genotoxic activity in all but one of the wastes that were mutagenic in Salmonella. Moreover, the Microscreen assay detected as genotoxic 5 additional wastes that were not detected in the Salmonella assay. The applicability of the Microscreen phage-induction assay for screening hazardous wastes for genotoxic activity is discussed along with some of the problems associated with screening highly toxic wastes containing toxic volatile compounds.

[Endonuclease modified comet assay for oxidative DNA damage induced by detection of genetic toxicants].

Science.gov (United States)

Zhao, Jian; Li, Hongli; Zhai, Qingfeng; Qiu, Yugang; Niu, Yong; Dai, Yufei; Zheng, Yuxin; Duan, Huawei

2014-03-01

The aim of this study was to investigate the use of the lesion-specific endonucleases-modified comet assay for analysis of DNA oxidation in cell lines. DNA breaks and oxidative damage were evaluated by normal alkaline and formamidopyrimidine-DNA-glycosylase (FPG) modified comet assays. Cytotoxicity were assessed by MTT method. The human bronchial epithelial cell (16HBE) were treated with benzo (a) pyrene (B(a)P), methyl methanesulfonate (MMS), colchicine (COL) and vincristine (VCR) respectively, and the dose is 20 µmol/L, 25 mg/ml, 5 mg/L and 0.5 mg/L for 24 h, respectively. Oxidative damage was also detected by levels of reactive oxygen species in treated cells. Four genotoxicants give higher cytotoxicity and no significant changes on parameters of comet assay treated by enzyme buffer. Cell survival rate were (59.69 ± 2.60) %, (54.33 ± 2.81) %, (53.11 ± 4.00) %, (51.43 ± 3.92) % in four groups, respectively. There was the direct DNA damage induced by test genotoxicants presented by tail length, Olive tail moment (TM) and tail DNA (%) in the comet assay. The presence of FPG in the assays increased DNA migration in treated groups when compared to those without it, and the difference was statistically significant which indicated that the clastogen and aneugen could induce oxidative damage in DNA strand. In the three parameters, the Olive TM was changed most obviously after genotoxicants treatment. In the contrast group, the Olive TM of B(a) P,MMS, COL,VCR in the contrast groups were 22.99 ± 17.33, 31.65 ± 18.86, 19.86 ± 9.56 and 17.02 ± 9.39, respectively, after dealing with the FPG, the Olive TM were 34.50 ± 17.29, 43.80 ± 10.06, 33.10 ± 12.38, 28.60 ± 10.53, increased by 58.94%, 38.48%, 66.86% and 68.21%, respectively (t value was 3.91, 3.89, 6.66 and 3.87, respectively, and all P comet assay appears more specific for detecting oxidative DNA damage induced by genotoxicants exposure, and the application of comet assay will be expanded. The endonuclease

Intracellular bacteria: the origin of dinoflagellate toxicity.

Science.gov (United States)

Silva, E S

1990-01-01

Dinoflagellate blooms of the same species have been registered either as toxic or nontoxic and, in the latter case, toxicity may be of different types. A hypothesis has been formulated according to which the bacteria having in some way taken part in the toxin formation are either inside the dinoflagellate cell or in the nutritive liquid. The presence of intracellular bacteria in those microorganisms has been studied mainly in material from cultures, a few from the sea, and several strains were isolated from different species. Experiments with crossed inoculations have shown that the bacterial strain from Gonyaulax tamarensis caused the cells of some other species to become toxic. From nontoxic clonal cultures of Prorocentrum balticum, Glenodinium foliaceum, and Gyrodinium instriatum, after inoculation of that bacterial strain, cultures were obtained whose cell extracts showed the same kind of toxicity as G. tamarensis. No toxic action could be found in the extracts of the bacterial cells form the assayed strains. The interference of intracellular bacteria in the metabolism of dinoflagellates must be the main cause of their toxicity.

Comparative Toxicity of Gasoline and Diesel Engine Emissions

Energy Technology Data Exchange (ETDEWEB)

JeanClare Seagrave; Joe L. Mauderly; Barbara Zielinska; John Sagebiel; Kevin Whitney; Doughlas R. Lawson; Michael Gurevich

2000-06-19

Better information on the comparative toxicity of airborne emissions from different types of engines is needed to guide the development of heavy vehicle engine, fuel, lubricant, and exhaust after-treatment technologies, and to place the health hazards of current heavy vehicle emissions in their proper perspective. To help fill this information gap, samples of vehicle exhaust particles and semi-volatile organic compounds (SVOC) were collected and analyzed. The biological activity of the combined particle-SVOC samples is being tested using standardized toxicity assays. This report provides an update on the design of experiments to test the relative toxicity of engine emissions from various sources.

Genotoxic and teratogenic potential of marine sediment extracts investigated with comet assay and zebrafish test

International Nuclear Information System (INIS)

Kammann, Ulrike; Biselli, Scarlett; Huehnerfuss, Heinrich; Reineke, Ninja; Theobald, Norbert; Vobach, Michael; Wosniok, Werner

2004-01-01

Organic extracts of marine sediments from the North Sea and the Baltic Sea were investigated with two toxicity assays. The comet assay based on the fish cell line Epithelioma papulosum cyprini (EPC) was applied to determine the genotoxic potential; zebrafish embryos (Danio rerio) were used to quantify the teratogenic potential of the samples. EC 50 values were calculated from dose-response curves for both test systems. Highest teratogenic and genotoxic effects normalised to total organic carbon (TOC) content were detected in sediment samples of different origins. Polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) are not likely to be the causes of the observed effects, as demonstrated by a two-step fractionation procedure of selected extracts. The toxic potential was more pronounced in fractions having polarity higher than those possessed by PAHs and PCBs. The suitability of the two in vitro test systems for assessing genotoxic and teratogenic effects of marine sediment extracts could be demonstrated. - Capsule: In vitro toxicity assays are used to assess genotoxic and teratogenic effects of environmental extracts

An in situ survey of the Paducah Gaseous Diffusion Plant and surrounding area

International Nuclear Information System (INIS)

Hoover, R.A.

1994-02-01

An in situ survey of the area surrounding the Paducah Gaseous Diffusion Plant was conducted between May 17 and 24, 1990. The survey consisted of in situ measurements and of ground sampling. A High Purity Germanium detector was used for the in situ measurements. The ground samples were taken to the, laboratory at EG ampersand G Energy Measurements, Inc., in Santa Barbara, California, for a radionuclide assay on a laboratory system. Results of the in situ measurements found evidence of naturally occurring radioisotopes, cesium-137 from international fallout, and some evidence of anomalous uranium-238. The soil sampling results show only the presence of naturally occurring radioisotopes, cesium-137, and also anomalous uranium-238

Bait-lamina assay as a tool to assess the effects of metal contamination in the feeding activity of soil invertebrates within a uranium mine area

International Nuclear Information System (INIS)

Andre, A.; Antunes, S.C.; Goncalves, F.; Pereira, R.

2009-01-01

As part of the tier 2 of a site-specific risk assessment, this study was the first reporting an intensive in situ application of the bait-lamina assay; two exposure periods (7 and 14 days) were tested during four seasons in ten different sites, within a uranium mine area and at two different depths. The most contaminated sites (by deposition of sludge from the effluent treatment pond) were discriminated after 14 days of exposure because extremely low percentages of feeding activity were recorded. Previous sub-lethal ecotoxicological assays, already had demonstrated that the habitat function of these soils is compromised. Nevertheless, seasonality has proved to have a significant influence on responses. Thus to strength conclusions about the impact of contaminants, the in situ bait-lamina assay should be performed on different annual seasons, at least for temperate regions. It was also found that some environmental parameters (e.g. soil moisture and litter) can act as confounding factors in the bait-lamina assay. - Bait-lamina assay for in situ evaluation of soil functions under site-specific risk assessments.

Making bio-sense of toxicity: new developments in whole-cell biosencors

DEFF Research Database (Denmark)

Sørensen, Søren Johannes; Burmølle, Mette; Hansen, Lars Hestbjerg

2006-01-01

Bacterial whole-cell biosensors are very useful for toxicity measurements of various samples. Semi-specific biosensors, containing fusions of stress-regulated promoters and reporter genes, have several advantages over the traditional, general biosensors that are based on constitutively expressed ....... The application of in situ inoculation and single-cell detection, combined with the introduction of new reporter genes and refined detection equipment, could lead to the extensive use of semi-specific, stress-responsive biosensors for toxicity estimations in the future....... reporter genes. Furthermore, semi-specific biosensors are constantly being refined to lower their sensitivity and, in combination, are able to detect a wide range of toxic agents. However, the requirement for a positive response of these biosensors to toxicants can result in false-negative responses...

A comprehensive study of the toxicity of natural multi-contaminated sediments: New insights brought by the use of a combined approach using the medaka embryo-larval assay and physico-chemical analyses.

Science.gov (United States)

Barjhoux, Iris; Clérandeau, Christelle; Menach, Karyn Le; Anschutz, Pierre; Gonzalez, Patrice; Budzinski, Hélène; Morin, Bénédicte; Baudrimont, Magalie; Cachot, Jérôme

2017-08-01

Sediment compartment is a long term sink for pollutants and a secondary source of contamination for aquatic species. The abiotic factors controlling the bioavailability and thus the toxicity of complex mixtures of pollutants accumulated in sediments are poorly documented. To highlight the different factors influencing sediment toxicity, we identified and analyzed the physico-chemical properties, micro-pollutant contents, and toxicity level of six contrasted sediments in the Lot-Garonne continuum. Sediment toxicity was evaluated using the recently described Japanese medaka (Oryzias latipes) embryo-larval assay with direct exposure to whole sediment (MELAc). Multiple toxicity endpoints including embryotoxicity, developmental defects and DNA damage were analyzed in exposed embryos. Chemical analyses revealed significant variations in the nature and contamination profile of sediments, mainly impacted by metallic trace elements and, unexpectedly, polycyclic aromatic hydrocarbons. Exposure to sediments induced different toxic impacts on medaka early life stages when compared with the reference site. Principal component analysis showed that the toxic responses following exposure to sediments from the Lot River and its tributary were associated with micro-pollutant contamination: biometric measurements, hatching success, genotoxicity, craniofacial deformities and yolk sac malabsorption were specifically correlated to metallic and organic contaminants. Conversely, the main biological responses following exposure to the Garonne River sediments were more likely related to their physico-chemical properties than to their contamination level. Time to hatch, cardiovascular injuries and spinal deformities were correlated to organic matter content, fine particles and dissolved oxygen levels. These results emphasize the necessity of combining physico-chemical analysis of sediment with toxicity assessment to accurately evaluate the environmental risks associated with sediment

Assessment of precision and concordance of quantitative mitochondrial DNA assays: a collaborative international quality assurance study

NARCIS (Netherlands)

Hammond, Emma L.; Sayer, David; Nolan, David; Walker, Ulrich A.; Ronde, Anthony de; Montaner, Julio S. G.; Cote, Helene C. F.; Gahan, Michelle E.; Cherry, Catherine L.; Wesselingh, Steven L.; Reiss, Peter; Mallal, Simon

2003-01-01

Background: A number of international research groups have developed DNA quantitation assays in order to investigate the role of mitochondrial DNA depletion in anti-retroviral therapy-induced toxicities. Objectives: A collaborative study was undertaken to evaluate intra-assay precision and between

Toxicity and Binding Profile of Lectins from the Genus Canavalia on Brine Shrimp

Directory of Open Access Journals (Sweden)

Francisco Vassiliepe Sousa Arruda

2013-01-01

Full Text Available Lectins are sugar-binding proteins widely distributed in nature with many biological functions. Although many lectins have a remarkable biotechnological potential, some of them can be cytotoxic. Thus, the aim of this study was to assess the toxicity of five lectins, purified from seeds of different species of Canavalia genus. In order to determine the toxicity, assays with Artemia nauplii were performed. In addition, a fluorescence assay was carried out to evaluate the binding of lectins to Artemia nauplii. In order to verify the relationship between the structure of lectins and their cytotoxic effect, structural analysis was carried out to evaluate the volume of the carbohydrate recognition domain (CRD of each lectin. The results showed that all lectins exhibited different toxicities and bound to a similar area in the digestive tract of Artemia nauplii. Concerning the structural analysis, differences in spatial arrangement and volume of CRD may explain the variation of the toxicity exhibited by each lectin. To this date, this is the first study that establishes a link between toxicity and structure of CRD from Diocleinae lectins.

An in vitro assay for compounds toxic to rumen protozoa

International Nuclear Information System (INIS)

Campbell, A.J.; Cumming, G.J.; Graham, C.A.; Leng, R.A.

1982-01-01

The viability of protozoa in whole rumen fluid was assessed by measuring the incorporation of Me- 14 C-choline in vitro. The use of the technique as an assay for testing antiprotozoal agents was evaluated with a variety of surfactant detergents which have previously been shown to have antiprotozoal activity in vivo. A good correlation was obtained between the potency of these compounds in vitro and in vivo. (auth)

A UK NEQAS ISH multicenter ring study using the Ventana HER2 dual-color ISH assay.

LENUS (Irish Health Repository)

Bartlett, J M S

2011-01-01

We performed a multicenter assessment of a new HER2 dual-color chromogenic in situ hybridization (CISH) test and herein report on concordance of CISH data with fluorescence in situ hybridization (FISH) data and intraobserver and interlaboratory scoring consistency. HER2 results were evaluated using duplicate cores from 30 breast cancers in 5 laboratories using the Ventana HER2 dual-color ISH assay (Ventana Medical Systems, Cambridgeshire, England) and in 1 central laboratory using a standard FISH assay. Overall 93.3% of cases were successfully analyzed by CISH across the 5 participating laboratories. There was excellent concordance (98.0% overall) for diagnosis of HER2 amplification by CISH compared with FISH. Intraobserver variability (7.7%) and intersite variability (9.1%) of absolute HER2\\/chromosome enumeration probe 17 ratios were tightly controlled across all participating laboratories. The Ventana HER2 dual-color ISH assay is robust and reproducible, shows good concordance with a standard FISH assay, and complies with requirements in national and international guidelines for performance of ISH-based diagnostic tests.

Earthworm Comet Assay for Assessing the Risk of Weathered Petroleum Hydrocarbon Contaminated Soils: Need to Look Further than Target Contaminants.

Science.gov (United States)

Ramadass, Kavitha; Palanisami, Thavamani; Smith, Euan; Mayilswami, Srinithi; Megharaj, Mallavarapu; Naidu, Ravi

2016-11-01

Earthworm toxicity assays contribute to ecological risk assessment and consequently standard toxicological endpoints, such as mortality and reproduction, are regularly estimated. These endpoints are not enough to better understand the mechanism of toxic pollutants. We employed an additional endpoint in the earthworm Eisenia andrei to estimate the pollutant-induced stress. In this study, comet assay was used as an additional endpoint to evaluate the genotoxicity of weathered hydrocarbon contaminated soils containing 520 to 1450 mg hydrocarbons kg -1 soil. Results showed that significantly higher DNA damage levels (two to sixfold higher) in earthworms exposed to hydrocarbon impacted soils. Interestingly, hydrocarbons levels in the tested soils were well below site-specific screening guideline values. In order to explore the reasons for observed toxicity, the contaminated soils were leached with rainwater and subjected to earthworm tests, including the comet assay, which showed no DNA damage. Soluble hydrocarbon fractions were not found originally in the soils and hence no hydrocarbons leached out during soil leaching. The soil leachate's Electrical Conductivity (EC) decreased from an average of 1665 ± 147 to 204 ± 20 µS cm -1 . Decreased EC is due to the loss of sodium, magnesium, calcium, and sulphate. The leachate experiment demonstrated that elevated salinity might cause the toxicity and not the weathered hydrocarbons. Soil leaching removed the toxicity, which is substantiated by the comet assay and soil leachate analysis data. The implication is that earthworm comet assay can be included in future eco (geno) toxicology studies to assess accurately the risk of contaminated soils.

Single-cell nanotoxicity assays of superparamagnetic iron oxide nanoparticles.

Science.gov (United States)

Eustaquio, Trisha; Leary, James F

2012-01-01

Properly evaluating the nanotoxicity of nanoparticles involves much more than bulk-cell assays of cell death by necrosis. Cells exposed to nanoparticles may undergo repairable oxidative stress and DNA damage or be induced into apoptosis. Exposure to nanoparticles may cause the cells to alter their proliferation or differentiation or their cell-cell signaling with neighboring cells in a tissue. Nanoparticles are usually more toxic to some cell subpopulations than others, and toxicity often varies with cell cycle. All of these facts dictate that any nanotoxicity assay must be at the single-cell level and must try whenever feasible and reasonable to include many of these other factors. Focusing on one type of quantitative measure of nanotoxicity, we describe flow and scanning image cytometry approaches to measuring nanotoxicity at the single-cell level by using a commonly used assay for distinguishing between necrotic and apoptotic causes of cell death by one type of nanoparticle. Flow cytometry is fast and quantitative, provided that the cells can be prepared into a single-cell suspension for analysis. But when cells cannot be put into suspension without altering nanotoxicity results, or if morphology, attachment, and stain location are important, a scanning image cytometry approach must be used. Both methods are described with application to a particular type of nanoparticle, a superparamagnetic iron oxide nanoparticle (SPION), as an example of how these assays may be applied to the more general problem of determining the effects of nanomaterial exposure to living cells.

Characterization and preliminary toxicity assay of nano-titanium dioxide additive in sugar-coated chewing gum.

Science.gov (United States)

Chen, Xin-Xin; Cheng, Bin; Yang, Yi-Xin; Cao, Aoneng; Liu, Jia-Hui; Du, Li-Jing; Liu, Yuanfang; Zhao, Yuliang; Wang, Haifang

2013-05-27

Nanotechnology shows great potential for producing food with higher quality and better taste through including new additives, improving nutrient delivery, and using better packaging. However, lack of investigations on safety issues of nanofood has resulted in public fears. How to characterize engineered nanomaterials in food and assess the toxicity and health impact of nanofood remains a big challenge. Herein, a facile and highly reliable separation method of TiO2 particles from food products (focusing on sugar-coated chewing gum) is reported, and the first comprehensive characterization study on food nanoparticles by multiple qualitative and quantitative methods is provided. The detailed information on nanoparticles in gum includes chemical composition, morphology, size distribution, crystalline phase, particle and mass concentration, surface charge, and aggregation state. Surprisingly, the results show that the number of food products containing nano-TiO2 (TiO2 in gum is nano-TiO2 , and it is unexpectedly easy to come out and be swallowed by a person who chews gum. Preliminary cytotoxicity assays show that the gum nano-TiO2 particles are relatively safe for gastrointestinal cells within 24 h even at a concentration of 200 μg mL(-1) . This comprehensive study demonstrates accurate physicochemical property, exposure, and cytotoxicity information on engineered nanoparticles in food, which is a prerequisite for the successful safety assessment of nanofood products. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acute toxicity and genotoxicity of fermented traditional medicine oyaksungi-san.

Science.gov (United States)

Park, Hwayong; Hwang, Youn-Hwan; Ma, Jin Yeul

2017-06-01

The traditional medicine oyaksungi-san (OY) has been prescribed in East Asia for hundreds of years for the treatment of stroke, paralysis, and ataxia. OY also has therapeutic effects on arthralgia, myalgia, and rheumatoid arthritis, and recent studies have shown its protective effects against apoptosis of hippocampal cells and its anti-inflammatory effects on the peripheral blood cells of patient with cerebral infarction. Many studies have explored the use of traditional medicine and herb materials in the development of safe, novel, and effective pharmaceuticals with fewer side effects. These efforts commonly adopt a bioconversion tool for fermentation with beneficial microbes. However, only pharmaceuticals with high levels of safety and low levels of toxicity can be used in healthcare system. OY water extract was fermented with Lactobacillus and assayed for acute toxicity and genotoxicity. Single dose acute toxicity, bacterial reverse mutation, chromosome aberrations, and micronucleus were observed and assayed in rats, histidine/tryptophan auxotrophic bacteria, Chinese hamster ovary fibroblast cells, and mice bone marrow cells, respectively. All the experimental animals showed no abnormal behavior, clinical signs, body weight increases, or mortality. In the bacterial cultures, no revertant colonies were observed. Morphological and numerical chromosomal aberrations were not found in all metaphases examined. Frequency of induced micronuclei was not significantly increased in all doses applied. As a whole, no acute toxicity or genotoxicity were observed in all the assays examined. Therefore, fermented OY is considered to be a safe material that can be used for development of complementary and alternative medicine using bioconversion.

Investigation of acute dermal irritation/corrosion, acute inhalation toxicity and cytotoxicity tests for Nanobiocide®

Directory of Open Access Journals (Sweden)

Mansour Hemmati

2016-07-01

Full Text Available Objective(s: Nanomaterials, especially silver Nanoparticles (Ag-NPs, are employed in an increasing number of commercial products. This has led to an ever growing exposure of human beings to this substance. The first purpose of the Nano Committee of Food and Drug Administration of The Islamic Republic of Iran (IFDA is developing guidelines to assess and approve commercial nano-health products for their safety of human applications. Nanobiocide® as a commercial product of stable colloid including 2000 ppm Ag-NPs for surface antimicrobial applications was investigated according to IFDA guidelines in the approval process. Methods: The first fabrication and characterization method of the product were determined. The human exposure to Nanobiocide® were studied by cytotoxicity assay, dermal irritation and inhalation toxicity assay based on the standard assay. Results: According to cytotoxicity assay by MTT method the concentration-dependent of cell viability was reduced and Inhibitory concentration-50 was about 1160 ppm. The Draize dermal irritation scoring system (DDIS showed no irritation to the skin of rabbits. No sign of gross toxicity, adverse pharmacological effect, or abnormal behavior based on inhalation toxicity was observed. Conclusions: The consideration of toxicity of Nanobiocide® is one of the major key for medical application. The results obtained revealed that the Nanobiocide® may be safe using in domestic and veterinary applications.

Ensuring the Quality of Stem Cell-Derived In Vitro Models for Toxicity Testing.

Science.gov (United States)

Stacey, Glyn N; Coecke, Sandra; Price, Anna-Bal; Healy, Lyn; Jennings, Paul; Wilmes, Anja; Pinset, Christian; Ingelman-Sundberg, Magnus; Louisse, Jochem; Haupt, Simone; Kidd, Darren; Robitski, Andrea; Jahnke, Heinz-Georg; Lemaitre, Gilles; Myatt, Glenn

Quality control of cell cultures used in new in vitro toxicology assays is crucial to the provision of reliable, reproducible and accurate toxicity data on new drugs or constituents of new consumer products. This chapter explores the key scientific and ethical criteria that must be addressed at the earliest stages of developing toxicology assays based on human pluripotent stem cell (hPSC) lines. It also identifies key considerations for such assays to be acceptable for regulatory, laboratory safety and commercial purposes. Also addressed is the development of hPSC-based assays for the tissue and cell types of greatest interest in drug toxicology. The chapter draws on a range of expert opinion within the European Commission/Cosmetics Europe-funded alternative testing cluster SEURAT-1 and consensus from international groups delivering this guidance such as the International Stem Cell Banking Initiative. Accordingly, the chapter summarizes the most up-date best practices in the use and quality control of human Pluripotent Stem Cell lines in the development of in vitro toxicity assays from leading experts in the field.

A High-Content Live-Cell Viability Assay and Its Validation on a Diverse 12K Compound Screen.

Science.gov (United States)

Chiaravalli, Jeanne; Glickman, J Fraser

2017-08-01

We have developed a new high-content cytotoxicity assay using live cells, called "ImageTOX." We used a high-throughput fluorescence microscope system, image segmentation software, and the combination of Hoechst 33342 and SYTO 17 to simultaneously score the relative size and the intensity of the nuclei, the nuclear membrane permeability, and the cell number in a 384-well microplate format. We then performed a screen of 12,668 diverse compounds and compared the results to a standard cytotoxicity assay. The ImageTOX assay identified similar sets of compounds to the standard cytotoxicity assay, while identifying more compounds having adverse effects on cell structure, earlier in treatment time. The ImageTOX assay uses inexpensive commercially available reagents and facilitates the use of live cells in toxicity screens. Furthermore, we show that we can measure the kinetic profile of compound toxicity in a high-content, high-throughput format, following the same set of cells over an extended period of time.

In Vivo Nanotoxicity Testing using the Zebrafish Embryo Assay.

Science.gov (United States)

Rizzo, Larissa Y; Golombek, Susanne K; Mertens, Marianne E; Pan, Yu; Laaf, Dominic; Broda, Janine; Jayapaul, Jabadurai; Möckel, Diana; Subr, Vladimir; Hennink, Wim E; Storm, Gert; Simon, Ulrich; Jahnen-Dechent, Willi; Kiessling, Fabian; Lammers, Twan

2013-06-10

Nanoparticles are increasingly used for biomedical purposes. Many different diagnostic and therapeutic applications are envisioned for nanoparticles, but there are often also serious concerns regarding their safety. Given the fact that numerous new nanomaterials are being developed every day, and that not much is known about the long-term toxicological impact of exposure to nanoparticles, there is an urgent need to establish efficient methods for nanotoxicity testing. The zebrafish (Danio rerio) embryo assay has recently emerged as an interesting 'intermediate' method for in vivo nanotoxicity screening, enabling (semi-) high-throughput analyses in a system significantly more complex than cultured cells, but at the same time also less 'invasive' and less expensive than large-scale biocompatibility studies in mice or rats. The zebrafish embryo assay is relatively well-established in the environmental sciences, but it has not yet gained wide notice in the nanomedicine field. Using prototypic polymeric drug carriers, gold-based nanodiagnostics and nanotherapeutics, and iron oxide-based nanodiagnostics, we here show that toxicity testing using zebrafish embryos is easy, efficient and informative, and faithfully reflects, yet significantly extends, cell-based toxicity testing. We therefore expect that the zebrafish embryo assay will become a popular future tool for in vivo nanotoxicity screening.

ToxiFly: Can Fruit Flies be Used to Identify Toxicity Pathways for Airborne Chemicals?

Science.gov (United States)

Current high-throughput and alternative screening assays for chemical toxicity are unable to test volatile organic compounds (VOCs), thus limiting their scope. Further, the data generated by these assays require mechanistic information to link effects at molecular targets to adve...

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

NARCIS (Netherlands)

Kroese, E.D.; Bosgra, S.; Buist, H.E.; Lewin, G.; Linden, S.C. van der; Man, H.Y.; Piersma, A.H.; Rorije, E.; Schulpen, S.H.W.; Schwarz, M.; Uibel, F.; Vugt-Lussenburg, B.M.A. van; Wolterbeek, A.P.M.; Burg, B. van der

2015-01-01

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

Toxicity of contaminants in lagoons and pannes of the Indiana Dunes National Lakeshore

International Nuclear Information System (INIS)

Gillespie, R.; Speelman, J.; Stewart, P.M.

1995-01-01

Contaminants in water and sediments of lagoons and pannes were 2--90 times greater at sites adjacent to slag and coal piles than those at reference sites. One site (Lagoon-US5) had sediments with very high concentrations of toxic organics (e.g. naphthalene, phenanthrene, dibenzofuran). Although analyses indicated a gradient of contaminant concentration with distance from their sources, toxicity assays were somewhat equivocal. With the exception of less reproduction in Ceriodaphnia at one lagoon site (US3 = 0.55 of reference), survival of fathead minnows and reproduction in Ceriodaphnia in lagoon and panne waters varied independently of the contaminant concentration. In fact, there was better Ceriodaphnia reproduction in water from two contaminated sites (Lagoon-US5, Panne-WP1) than in water from reference sites. Fathead minnow survival, Ceriodaphnia survival, Ceriodaphnia reproduction, amphipod survival, and amphipod growth varied among sites in toxicity assays with sediments, 100% mortality of fatheads at Lagoon-US5, 100% mortality of Ceriodaphnia at Lagoon-US3, and less survival of fathead minnows at Lagoon-US3 indicate possible toxicity from contaminants in sediments at these sites. Of all organisms and end-points tested, Ceriodaphnia survival seemed to be most closely associated with concentrations of contaminants in lagoon water and sediments. Amphipod survival also varied with contaminants in sediments, however, survival in sediments of contaminated sites ranged only from 0.90--0.93 of reference sites. Although the results are not consistent among organisms, toxicity assays indicate that sediments from the lagoon site with the highest contaminants (Lagoon-US5) and possibly those from another contaminated lagoon site (Lagoon-US3) could be toxic to aquatic organisms. Water and sediments from contaminated panne sites do not appear to be toxic to aquatic test organisms

Quantifying engineered nanomaterial toxicity: comparison of common cytotoxicity and gene expression measurements

Directory of Open Access Journals (Sweden)

Donald H. Atha

2017-11-01

Full Text Available Abstract Background When evaluating the toxicity of engineered nanomaterials (ENMS it is important to use multiple bioassays based on different mechanisms of action. In this regard we evaluated the use of gene expression and common cytotoxicity measurements using as test materials, two selected nanoparticles with known differences in toxicity, 5 nm mercaptoundecanoic acid (MUA-capped InP and CdSe quantum dots (QDs. We tested the effects of these QDs at concentrations ranging from 0.5 to 160 µg/mL on cultured normal human bronchial epithelial (NHBE cells using four common cytotoxicity assays: the dichlorofluorescein assay for reactive oxygen species (ROS, the lactate dehydrogenase assay for membrane viability (LDH, the mitochondrial dehydrogenase assay for mitochondrial function, and the Comet assay for DNA strand breaks. Results The cytotoxicity assays showed similar trends when exposed to nanoparticles for 24 h at 80 µg/mL with a threefold increase in ROS with exposure to CdSe QDs compared to an insignificant change in ROS levels after exposure to InP QDs, a twofold increase in the LDH necrosis assay in NHBE cells with exposure to CdSe QDs compared to a 50% decrease for InP QDs, a 60% decrease in the mitochondrial function assay upon exposure to CdSe QDs compared to a minimal increase in the case of InP and significant DNA strand breaks after exposure to CdSe QDs compared to no significant DNA strand breaks with InP. High-throughput quantitative real-time polymerase chain reaction (qRT-PCR data for cells exposed for 6 h at a concentration of 80 µg/mL were consistent with the cytotoxicity assays showing major differences in DNA damage, DNA repair and mitochondrial function gene regulatory responses to the CdSe and InP QDs. The BRCA2, CYP1A1, CYP1B1, CDK1, SFN and VEGFA genes were observed to be upregulated specifically from increased CdSe exposure and suggests their possible utility as biomarkers for toxicity. Conclusions This study can

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

NARCIS (Netherlands)

Park, M.V.; Annema, W.; Salvati, A.; Lesniak, A.; Elsaesser, A.; Barnes, C.; McKerr, G.; Howard, C.; Lynch, I.; Dawson, K.; Piersma, A.H.; de Jong, W.H.

2009-01-01

While research into the potential toxic properties of nanomaterials is now increasing, the area of developmental toxicity has remained relatively uninvestigated. The embryonic stem cell test is an in vitro screening assay used to investigate the embryotoxic potential of chemicals by determining

A biological method for in-situ synthesis of hydroxyapatite-coated magnetite nanoparticles using Enterobacter aerogenes: Characterization and acute toxicity assessments.

Science.gov (United States)

Ahmadzadeh, Elham; Talebnia Rowshan, Farid; Hosseini, Morteza

2017-04-01

Hydroxyapatite (HA)-coated magnetite nanoparticles (MNPs) are being widely investigated for various applications in medical engineering and wastewater treatment. In this work, the MNPs were thoroughly coated by bacterial synthesized HA nanoparticles during biomineralization process using Enterobacter aerogenes. The resulting bacterial-induced precipitate was then calcined at 600°C and investigated with respect to structural characteristics, particle size and magnetic strength by XRD, FT-IR, SEM, EDS, TEM and VSM analyses. The effects of MNPs and HA-coated MNPs (HA-MNPs) on the viability of human MCF-7 cell lines were also investigated via mitochondrial activity test (MTT) and lactate dehydrogenase (LDH) assays. The powder characterization results showed appropriate structural properties for HA-MNPs samples. The particles diameter size of the MNPs and HA-MNPs were in the range of 3-25nm and 20-80nm, respectively. The biologically-synthesized HA-MNPs formed a stable suspension in water while keeping their magnetic property. The saturation magnetization (Ms) of HA-MNPs was measured at ~10emug -1 which was in good agreement with the structural composition of this sample. Finally, the results of the cell lines viability indicated that coating of toxic MNPs via biomineralization was a promising approach in order to synthesize bio-compatible magnetic nanoparticles with suitable physical and chemical structural characteristics. The toxicity level of MNPs was reduced by 10 fold when coated by bacterial-synthesized HA. Copyright © 2016 Elsevier B.V. All rights reserved.

Acute toxicity and associated mechanisms of four strobilurins in algae.

Science.gov (United States)

Liu, Xiaoxu; Wang, Yu; Chen, Hao; Zhang, Junli; Wang, Chengju; Li, Xuefeng; Pang, Sen

2018-04-03

Strobilurins have been reported highly toxic to non-target aquatic organisms but few illustrated how they cause toxic effects on algae. This study investigated the acute toxicity of Kresoxim-methy (KRE), Pyraclostrobin (PYR), Trifloxystrobin (TRI) and Picoxystrobin (PIC) on two algae and their toxicity mechanisms. Four strobilurins showed lower toxic effects on Chlorella pyrenoidsa but higher on Chlorella vulgaris. bc1 complex activities in C. vulgaris were significantly inhibited by all strobilurins, suggesting bc 1 complex might be the target of strobilurin toxicity in algae. Moreover, SOD, CAT and POD activities were significantly up-regulated by all doses of KRE, PYR and PIC. In contrast, low concentrations of TRI stimulated SOD and POD activities but highest concentration significantly inhibited those activities. Comet assays showed damaged DNA in C. vulgaris by four strobulirins, suggesting their potential genotoxic threats to algae. The results illustrated acute toxicity by strobulirins on algae and their possible toxicity mechanisms. Copyright © 2018 Elsevier B.V. All rights reserved.

Silver Accumulation in the Green Microalga Coccomyxa actinabiotis: Toxicity, in Situ Speciation, and Localization Investigated Using Synchrotron XAS, XRD, and TEM.

Science.gov (United States)

Leonardo, Thomas; Farhi, Emmanuel; Pouget, Stéphanie; Motellier, Sylvie; Boisson, Anne-Marie; Banerjee, Dipanjan; Rébeillé, Fabrice; den Auwer, Christophe; Rivasseau, Corinne

2016-01-05

Microalgae are good candidates for toxic metal remediation biotechnologies. This study explores the cellular processes implemented by the green microalga Coccomyxa actinabiotis to take up and cope with silver over the concentration range of 10(-7) to 10(-2) M Ag(+). Understanding these processes enables us to assess the potential of this microalga for applications for bioremediation. Silver in situ speciation and localization were investigated using X-ray absorption spectroscopy, X-ray diffraction, and transmission electron microscopy. Silver toxicity was evaluated by monitoring microalgal growth and photochemical parameters. Different accumulation mechanisms were brought out depending on silver concentration. At low micromolar concentration, microalgae fixed all silver initially present in solution, trapping it inside the cells into the cytosol, mainly as unreduced Ag(I) bound with molecules containing sulfur. Silver was efficiently detoxified. When concentration increased, silver spread throughout the cell and particularly entered the chloroplast, where it damaged the photosystem. Most silver was reduced to Ag(0) and aggregated to form crystalline silver nanoparticles of face-centered cubic structure with a mean size of 10 nm. An additional minor interaction of silver with molecules containing sulfur indicated the concomitant existence of the mechanism observed at low concentration or nanoparticle capping. Nanoparticles were observed in chloroplasts, in mitochondria, on the plasma membrane, on cytosolic membrane structures, and in vacuoles. Above 10(-4) M Ag(+), damages were irreversible, and photosynthesis and growth were definitely inhibited. However, high silver amounts remained confined inside microalgae, showing their potential for the bioremediation of contaminated water.

Flow cytometric assay for analysis of cytotoxic effects of potential drugs on human peripheral blood leukocytes

Science.gov (United States)

Nieschke, Kathleen; Mittag, Anja; Golab, Karolina; Bocsi, Jozsef; Pierzchalski, Arkadiusz; Kamysz, Wojciech; Tarnok, Attila

2014-03-01

Toxicity test of new chemicals belongs to the first steps in the drug screening, using different cultured cell lines. However, primary human cells represent the human organism better than cultured tumor derived cell lines. We developed a very gentle toxicity assay for isolation and incubation of human peripheral blood leukocytes (PBL) and tested it using different bioactive oligopeptides (OP). Effects of different PBL isolation methods (red blood cell lysis; Histopaque isolation among others), different incubation tubes (e.g. FACS tubes), anticoagulants and blood sources on PBL viability were tested using propidium iodide-exclusion as viability measure (incubation time: 60 min, 36°C) and flow cytometry. Toxicity concentration and time-depended effects (10-60 min, 36 °C, 0-100 μg /ml of OP) on human PBL were analyzed. Erythrocyte lysis by hypotonic shock (dH2O) was the fastest PBL isolation method with highest viability (>85%) compared to NH4Cl-Lysis (49%). Density gradient centrifugation led to neutrophil granulocyte cell loss. Heparin anticoagulation resulted in higher viability than EDTA. Conical 1.5 mL and 2 mL micro-reaction tubes (both polypropylene (PP)) had the highest viability (99% and 97%) compared to other tubes, i.e. three types of 5.0 mL round-bottom tubes PP (opaque-60%), PP (blue-62%), Polystyrene (PS-64%). Viability of PBL did not differ between venous and capillary blood. A gentle reproducible preparation and analytical toxicity-assay for human PBL was developed and evaluated. Using our assay toxicity, time-course, dose-dependence and aggregate formation by OP could be clearly differentiated and quantified. This novel assay enables for rapid and cost effective multiparametric toxicological screening and pharmacological testing on primary human PBL and can be adapted to high-throughput-screening.°z

heavy metal fixation in contaminated soil using non-toxic agents

African Journals Online (AJOL)

USER

2013-05-08

May 8, 2013 ... agricultural ecosystems (Chukwuka and Omotayo,. 2008), as well as remediation of former industrial sites which have been exposed to diffuse pollution by toxic heavy metals (Finžgar et al., 2006; Belviso et al., 2010). Among the remediation technologies available for contaminated sites, in situ (in place) ...

In situ nitrate from groundwater using freely available carbon material at an industrially polluted site

CSIR Research Space (South Africa)

Israel, S

2011-09-01

Full Text Available concentrations, nitrate in drinking water can be toxic to infants and young animals. In situ treatment could be a robust and effective technique for removal of nitrate, iron and manganese....

Toxicity assessments of nonsteroidal anti-inflammatory drugs in isolated mitochondria, rat hepatocytes, and zebrafish show good concordance across chemical classes

Energy Technology Data Exchange (ETDEWEB)

Nadanaciva, Sashi [Compound Safety Prediction, Worldwide Medicinal Chemistry, Pfizer, Inc., Groton, CT 06340 (United States); Aleo, Michael D. [Drug Safety Research and Development, Pfizer Inc., Groton, CT 06340 (United States); Strock, Christopher J. [Cyprotex US, Watertown, MA 02472 (United States); Stedman, Donald B. [Drug Safety Research and Development, Pfizer Inc., Groton, CT 06340 (United States); Wang, Huijun [Computational Sciences, Pfizer Inc., Groton, CT 06340 (United States); Will, Yvonne, E-mail: yvonne.will@pfizer.com [Compound Safety Prediction, Worldwide Medicinal Chemistry, Pfizer, Inc., Groton, CT 06340 (United States)

2013-10-15

To reduce costly late-stage compound attrition, there has been an increased focus on assessing compounds in in vitro assays that predict attributes of human safety liabilities, before preclinical in vivo studies are done. Relevant questions when choosing a panel of assays for predicting toxicity are (a) whether there is general concordance in the data among the assays, and (b) whether, in a retrospective analysis, the rank order of toxicity of compounds in the assays correlates with the known safety profile of the drugs in humans. The aim of our study was to answer these questions using nonsteroidal anti-inflammatory drugs (NSAIDs) as a test set since NSAIDs are generally associated with gastrointestinal injury, hepatotoxicity, and/or cardiovascular risk, with mitochondrial impairment and endoplasmic reticulum stress being possible contributing factors. Eleven NSAIDs, flufenamic acid, tolfenamic acid, mefenamic acid, diclofenac, meloxicam, sudoxicam, piroxicam, diflunisal, acetylsalicylic acid, nimesulide, and sulindac (and its two metabolites, sulindac sulfide and sulindac sulfone), were tested for their effects on (a) the respiration of rat liver mitochondria, (b) a panel of mechanistic endpoints in rat hepatocytes, and (c) the viability and organ morphology of zebrafish. We show good concordance for distinguishing among/between NSAID chemical classes in the observations among the three approaches. Furthermore, the assays were complementary and able to correctly identify “toxic” and “non-toxic” drugs in accordance with their human safety profile, with emphasis on hepatic and gastrointestinal safety. We recommend implementing our multi-assay approach in the drug discovery process to reduce compound attrition. - Highlights: • NSAIDS cause liver and GI toxicity. • Mitochondrial uncoupling contributes to NSAID liver toxicity. • ER stress is a mechanism that contributes to liver toxicity. • Zebrafish and cell based assays are complimentary.

Toxicity assessments of nonsteroidal anti-inflammatory drugs in isolated mitochondria, rat hepatocytes, and zebrafish show good concordance across chemical classes

International Nuclear Information System (INIS)

Nadanaciva, Sashi; Aleo, Michael D.; Strock, Christopher J.; Stedman, Donald B.; Wang, Huijun; Will, Yvonne

2013-01-01

To reduce costly late-stage compound attrition, there has been an increased focus on assessing compounds in in vitro assays that predict attributes of human safety liabilities, before preclinical in vivo studies are done. Relevant questions when choosing a panel of assays for predicting toxicity are (a) whether there is general concordance in the data among the assays, and (b) whether, in a retrospective analysis, the rank order of toxicity of compounds in the assays correlates with the known safety profile of the drugs in humans. The aim of our study was to answer these questions using nonsteroidal anti-inflammatory drugs (NSAIDs) as a test set since NSAIDs are generally associated with gastrointestinal injury, hepatotoxicity, and/or cardiovascular risk, with mitochondrial impairment and endoplasmic reticulum stress being possible contributing factors. Eleven NSAIDs, flufenamic acid, tolfenamic acid, mefenamic acid, diclofenac, meloxicam, sudoxicam, piroxicam, diflunisal, acetylsalicylic acid, nimesulide, and sulindac (and its two metabolites, sulindac sulfide and sulindac sulfone), were tested for their effects on (a) the respiration of rat liver mitochondria, (b) a panel of mechanistic endpoints in rat hepatocytes, and (c) the viability and organ morphology of zebrafish. We show good concordance for distinguishing among/between NSAID chemical classes in the observations among the three approaches. Furthermore, the assays were complementary and able to correctly identify “toxic” and “non-toxic” drugs in accordance with their human safety profile, with emphasis on hepatic and gastrointestinal safety. We recommend implementing our multi-assay approach in the drug discovery process to reduce compound attrition. - Highlights: • NSAIDS cause liver and GI toxicity. • Mitochondrial uncoupling contributes to NSAID liver toxicity. • ER stress is a mechanism that contributes to liver toxicity. • Zebrafish and cell based assays are complimentary

An improved method for the assay of platelet pyruvate dehydrogenase

International Nuclear Information System (INIS)

Schofield, P.J.; Griffiths, L.R.; Rogers, S.H.

1980-01-01

An improved method for the assay of human platelet pyruvate dehydrogenase is described. By generating the substrate [1- 14 C]pyruvate in situ from [1- 14 C]lactate plus L-lactate dehydrogenase, the rate of spontaneous decarboxylation is dramatically reduced, allowing far greater sensitivity in the assay of low activities of pyruvate dehydrogenase. In addition, no special precautions are required for the storage and use of [1- 14 C]lactate, in contrast to those for [1- 14 C]pyruvate. These factors allow a 5-10-fold increase in sensitivity compared with current methods. The pyruvate dehydrogenase activity of normal subjects as determined by the [1- 14 C]lactate system was 215+-55 pmol min -1 mg -1 protein (n=18). The advantages of this assay system are discussed. (Auth.)

Use of higher plants as screens for toxicity assessment.

Science.gov (United States)

Kristen, U

1997-01-01

This review deals with the use of entire plants, seedlings, cell suspension cultures and pollen tubes for the estimation of potential toxicity in the environment, and for risk assessment of chemicals and formulations of human relevance. It is shown that the roots of onions and various crop seedlings, as well as in vitro growing pollen tubes of some mono- and dicotyledonous plants, are most frequently used to obtain toxicity data by determination of root and tube growth inhibition. Both roots and pollen tubes are chloroplast free, non-photosynthetic systems and, therefore, with regard to their cytotoxic reactions are closer to vertebrate tissues and cells than are chloroplast-containing plant organs. Root tips and anthers of flower buds are shown to be applicable to genotoxicity screening by microscopic analysis of mitotic or meiotic aberrations during cell division or microspore development, respectively. The processes of mitosis and meiosis are similar in plants and animals. Therefore, meristematic and sporogenic tissues of plants generally show patterns of cytotoxic response similar to those of embryogenic and spermatogenic tissues of vertebrates. The suitability of root tips, cell suspensions and pollen tubes for the investigation of mechanisms of toxic action and for the analysis of structure-activity relationships is also demonstrated. Two plant-based assays, the Allium test and the pollen tube growth test, both currently being evaluated alongside with established mammalian in vivo and in vitro protocols, are emphasized with regard to their potential use as alternatives to animal in vivo toxicity tests. For both assays, preliminary results indicate that the tips of growing roots and the rapidly elongating pollen tubes of certain higher plant species are as reliable as mammalian cell lines for detecting basal cytotoxicity. It is suggested that seeds and pollen grains, in particular, provide easily storable and convenient systems for inexpensive, relatively

Hyperpolarized NMR Probes for Biological Assays

Directory of Open Access Journals (Sweden)

Sebastian Meier

2014-01-01

Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.

A miniature TDCR system dedicated to in-situ activity assay

International Nuclear Information System (INIS)

Johansson, Lena; Bakhshandeiar, Eleanor; Pearce, Andy; Collins, Sean; Orlandini, Pascal; Sephton, John

2014-01-01

In the framework of the European Metrology Research Programme (EMRP), the Joint Research Project MetroFission has a dedicated work package for the development of a portable Triple-to-Double-Coincidence-Ratio (TDCR) system dedicated to in-situ activity measurements of low-energy beta emitters arising from the operation of the next generation of nuclear power plants. In the design phase of the NPL version of the mini-TDCR, a wide range of metrological aspects and detector types was considered. This paper summarizes these aspects of design, in the light of previous experience with the primary TDCR system at NPL. For example, in this miniature version of the TDCR, the optical chamber was simplified and cylindrical geometry was deemed sufficient. The reflectivity of the surface was increased by painted layers of Spectraflect ® , a specially formulated barium sulphate coating with high reflectivity across a wide range of wave lengths including UV. This option was chosen rather than the high performing and more expensive Spectralon ® material used for the primary NPL TDCR. The miniature TDCR system is intended for on-site monitoring and will not require as high a performance as the primary system. Other factors that were considered included sample changing, light tightness, type of photo detector, method for varying the detection efficiency, shielding and the possible addition of an internal gamma-ray source for determination of the quench parameter of the source. In this version, the sample changing is performed using a piston and an automatic shutter. Significant design effort has been applied to ensure minimal ingress of light from the piston. Efficiency variation is accomplished by increasing the vertical displacement of the vial. Provision has been made to automate this at a later stage. Maximum light transmission to the photo-multiplier tubes is obtained at the “zero” reference height. Validation measurements were successfully performed using four different

Toxicity and bioaccumulation of sediment-associated silvernanoparticles in the estuarine polychaete, Nereis (Hediste) diversicolor

DEFF Research Database (Denmark)

Cong, Yi; Banta, Gary Thomas; Selck, Henriette

2014-01-01

damage (comet assay tail moment and tail DNA intensity %) of Nereis coelomocytes increased in a concentration-dependent manner in all three Ag treatments. Ag NP treatments were more toxic than aqueous Ag for all toxicity endpoints, even though bioaccumulation did not differ significantly among Ag forms...

Multiple-endpoint assay provides a detailed mechanistic view of responses to herbicide exposure in Chlamydomonas reinhardtii

International Nuclear Information System (INIS)

Nestler, Holger; Groh, Ksenia J.; Schönenberger, René; Behra, Renata; Schirmer, Kristin; Eggen, Rik I.L.; Suter, Marc J.-F.

2012-01-01

The release of herbicides into the aquatic environment raises concerns about potential detrimental effects on ecologically important non-target species, such as unicellular algae, necessitating ecotoxicological risk assessment. Algal toxicity tests based on growth, a commonly assessed endpoint, are integrative, and hence do not provide information about underlying toxic mechanisms and effects. This limitation may be overcome by measuring more specific biochemical and physiological endpoints. In the present work, we developed and applied a novel multiple-endpoint assay, and analyzed the effects of the herbicides paraquat, diuron and norflurazon, each representing a specific mechanism of toxic action, on the single celled green alga Chlamydomonas reinhardtii. The endpoints added to assessment of growth were pigment content, maximum and effective photosystem II quantum yield, ATP content, esterase and oxidative activity. All parameters were measured at 2, 6 and 24 h of exposure, except for growth and pigment content, which were determined after 6 and 24 h only. Effective concentrations causing 50% of response (EC50s) and lowest observable effect concentrations (LOECs) were determined for all endpoints and exposure durations where possible. The assay provided a detailed picture of the concentration- and time-dependent development of effects elicited by the analyzed herbicides, thus improving the understanding of the underlying toxic mechanisms. Furthermore, the response patterns were unique to the respective herbicide and reflected the different mechanisms of toxicity. The comparison of the endpoint responses and sensitivities revealed that several physiological and biochemical parameters reacted earlier or stronger to disturbances than growth. Overall, the presented multiple-endpoint assay constitutes a promising basis for investigating stressor and toxicant effects in green algae.

Multiple-endpoint assay provides a detailed mechanistic view of responses to herbicide exposure in Chlamydomonas reinhardtii

Energy Technology Data Exchange (ETDEWEB)

Nestler, Holger [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); Groh, Ksenia J.; Schoenenberger, Rene; Behra, Renata [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); Schirmer, Kristin [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); EPF Lausanne, School of Architecture, Civil and Environmental Engineering, 1015 Lausanne (Switzerland); Eggen, Rik I.L. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland); Suter, Marc J.-F., E-mail: suter@eawag.ch [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, 8600 Duebendorf (Switzerland); ETH Zurich, Swiss Federal Institute of Technology, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich (Switzerland)

2012-04-15

The release of herbicides into the aquatic environment raises concerns about potential detrimental effects on ecologically important non-target species, such as unicellular algae, necessitating ecotoxicological risk assessment. Algal toxicity tests based on growth, a commonly assessed endpoint, are integrative, and hence do not provide information about underlying toxic mechanisms and effects. This limitation may be overcome by measuring more specific biochemical and physiological endpoints. In the present work, we developed and applied a novel multiple-endpoint assay, and analyzed the effects of the herbicides paraquat, diuron and norflurazon, each representing a specific mechanism of toxic action, on the single celled green alga Chlamydomonas reinhardtii. The endpoints added to assessment of growth were pigment content, maximum and effective photosystem II quantum yield, ATP content, esterase and oxidative activity. All parameters were measured at 2, 6 and 24 h of exposure, except for growth and pigment content, which were determined after 6 and 24 h only. Effective concentrations causing 50% of response (EC50s) and lowest observable effect concentrations (LOECs) were determined for all endpoints and exposure durations where possible. The assay provided a detailed picture of the concentration- and time-dependent development of effects elicited by the analyzed herbicides, thus improving the understanding of the underlying toxic mechanisms. Furthermore, the response patterns were unique to the respective herbicide and reflected the different mechanisms of toxicity. The comparison of the endpoint responses and sensitivities revealed that several physiological and biochemical parameters reacted earlier or stronger to disturbances than growth. Overall, the presented multiple-endpoint assay constitutes a promising basis for investigating stressor and toxicant effects in green algae.

Quantum Dot Nanotoxicity Investigations Using Human Lung Cells and TOXOR Electrochemical Enzyme Assay Methodology.

Science.gov (United States)

O'Hara, Tony; Seddon, Brian; O'Connor, Andrew; McClean, Siobhán; Singh, Baljit; Iwuoha, Emmanuel; Fuku, Xolile; Dempsey, Eithne

2017-01-27

Recent studies have suggested that certain nanomaterials can interfere with optically based cytotoxicity assays resulting in underestimations of nanomaterial toxicity. As a result there has been growing interest in the use of whole cell electrochemical biosensors for nanotoxicity applications. Herein we report application of an electrochemical cytotoxicity assay developed in house (TOXOR) in the evaluation of toxic effects of mercaptosuccinic acid capped cadmium telluride quantum dots (MSA capped CdTe QDs), toward mammalian cells. MSA capped CdTe QDs were synthesized, characterized, and their cytotoxicity toward A549 human lung epithelial cells investigated. The internalization of QDs within cells was scrutinized via confocal microscopy. The cytotoxicity assay is based on the measurement of changes in cellular enzyme acid phosphatase upon 24 h exposure to QDs. Acid phosphatase catalyzes dephosphorylation of 2-naphthyl phosphate to 2-naphthol (determined by chronocoulometry) and is indicative of metabolic activity in cells. The 24 h IC50 (concentration resulting in 50% reduction in acid phosphatase activity) value for MSA capped CdTe QDs was found to be 118 ± 49 μg/mL using the TOXOR assay and was in agreement with the MTT assay (157 ± 31 μg/mL). Potential uses of this electrochemical assay include the screening of nanomaterials, environmental toxins, in addition to applications in the pharmaceutical, food, and health sectors.

Transcriptomic analyses in a benthic fish exposed to contaminated estuarine sediments through laboratory and in situ bioassays.

Science.gov (United States)

Costa, Pedro M; Miguel, Célia; Caeiro, Sandra; Lobo, Jorge; Martins, Marta; Ferreira, Ana M; Caetano, Miguel; Vale, Carlos; DelValls, T A; Costa, Maria H

2011-11-01

The transcription of contaminant response-related genes was investigated in juvenile Senegalese soles exposed to sediments from three distinct sites (a reference plus two contaminated) of a Portuguese estuary (the Sado, W Portugal) through simultaneous 28-day laboratory and in situ bioassays. Transcription of cytochrome P450 1A (CYP1A), metallothionein 1 (MT1), glutathione peroxidase (GPx), catalase (CAT), caspase 3 (CASP3) and 90 kDa heat-shock protein alpha (HSP90AA) was surveyed in the liver by real-time PCR. CASP3 transcription analysis was complemented by surveying apoptosis through the TUNEL reaction. After 14 days of exposure, relative transcription was either reduced or decreased in fish exposed to the contaminated sediments, revealing a disturbance stress phase during which animals failed to respond to insult. After 28 days of exposure all genes' transcription responded to contamination but laboratory and in situ assays depicted distinct patterns of regulation. Although sediments revealed a combination of organic and inorganic toxicants, transcription of the CYP1A gene was consistently correlated to organic contaminants. Metallothionein regulation was found correlated to metallic and organic xenobiotic contamination in the laboratory and in situ, respectively. The transcription of oxidative stress-related genes can be a good indicator of general stress but caution is mandatory when interpreting the results since regulation may be influenced by multiple factors. As for MT1, HSP90 up-regulation has potential to be a good indicator for total contamination, as well as the CASP3 gene, even though hepatocyte apoptosis depicted values inconsistent with sediment contamination, showing that programmed cell death did not directly depend on caspase transcription alone.

Test plan for Digface Chemical and Radiation Assay System

International Nuclear Information System (INIS)

Akers, D.W.

1993-07-01

The Digface Chemical and Radiation Assay System (CRAS) Project will develop a sensor using Prompt Gamma Neutron Activation Analysis (PGNAA) that can detect the present of hazardous chemicals and radioactive materials. The CRAS is being designed for in situ assay of closed drums and contaminated soils for gamma-ray emitting radionuclides and hazardous elements. The CRAS is based upon the use of 252 Cf PGNAA with a germanium gamma-ray spectrometer as the analyzer. Tasks being performed include determining detection limits for a number of hazardous chemicals and assessing matrix and transmission effects through soil. Initial analyses suggest that the technique is applicable to a number of hazardous materials such as trichloroethane and carbon tetrachloride

In-situ remediation system for groundwater and soils

Science.gov (United States)

Corey, John C.; Kaback, Dawn S.; Looney, Brian B.

1993-01-01

A method and system for in-situ remediation of contaminated groundwater and soil where the contaminants, such as toxic metals, are carried in a subsurface plume. The method comprises selection and injection into the soil of a fluid that will cause the contaminants to form stable, non-toxic compounds either directly by combining with the contaminants or indirectly by creating conditions in the soil or changing the conditions of the soil so that the formation of stable, non-toxic compounds between the contaminants and existing substances in the soil are more favorable. In the case of non-toxic metal contaminants, sulfides or sulfates are injected so that metal sulfides or sulfates are formed. Alternatively, an inert gas may be injected to stimulate microorganisms in the soil to produce sulfides which, in turn, react with the metal contaminants. Preferably, two wells are used, one to inject the fluid and one to extract the unused portion of the fluid. The two wells work in combination to create a flow of the fluid across the plume to achieve better, more rapid mixing of the fluid and the contaminants.

Prognostic Significance of Telomere Attrition in Ductal Carcinoma in Situ of the Breast

National Research Council Canada - National Science Library

Griffith, Jeffrey K

2008-01-01

We are using an innovative, quantitative assay for telomere DNA content (TC) developed and characterized by the PI, to test the hypothesis that TC predicts the likelihood of disease recurrence in women with ductal carcinoma in situ (DCIS...

Complementing in vitro screening assays with in silico ...

Science.gov (United States)

High-throughput in vitro assays offer a rapid, cost-efficient means to screen thousands of chemicals across hundreds of pathway-based toxicity endpoints. However, one main concern involved with the use of in vitro assays is the erroneous omission of chemicals that are inactive under assay conditions but that can generate active metabolites under in vivo conditions. To address this potential issue, a case study will be presented to demonstrate the use of in silico tools to identify inactive parents with the ability to generate active metabolites. This case study used the results from an orthogonal assay designed to improve confidence in the identification of active chemicals tested across eighteen estrogen receptor (ER)-related in vitro assays by accounting for technological limitations inherent within each individual assay. From the 1,812 chemicals tested within the orthogonal assay, 1,398 were considered inactive. These inactive chemicals were analyzed using Chemaxon Metabolizer software to predict the first and second generation metabolites. From the nearly 1,400 inactive chemicals, over 2,200 first-generation (i.e., primary) metabolites and over 5,500 second-generation (i.e., secondary) metabolites were predicted. Nearly 70% of primary metabolites were immediately detoxified or converted to other metabolites, while over 70% of secondary metabolites remained stable. Among these predicted metabolites, those that are most likely to be produced and remain

Proximity probing assays for simultaneous visualization of protein complexes in situ

DEFF Research Database (Denmark)

Moreira, José; Thorsen, Stine Buch; Brünner, Nils

2013-01-01

EVALUATION OF: Leuchowius KJ, Clausson CM, Grannas K et al. Parallel visualization of multiple protein complexes in individual cells in tumor tissue. Mol. Cell Proteomics doi:10.1074/mcp.O112.023374 (2013) (Epub ahead of print). Techniques for in situ detection and quantification of proteins...... in fixed tissue remain an important element of both basic biological analyses and clinical biomarker research. The practical importance of such techniques can be exemplified by the everyday clinical use of immunohistochemical detection of the estrogen receptor and HER2 in tissues from breast cancer...

Toxicity of medicinal plants used in traditional medicine in Northern Peru.

Science.gov (United States)

Bussmann, R W; Malca, G; Glenn, A; Sharon, D; Nilsen, B; Parris, B; Dubose, D; Ruiz, D; Saleda, J; Martinez, M; Carillo, L; Walker, K; Kuhlman, A; Townesmith, A

2011-09-01

The plant species reported here are traditionally used in Northern Peru for a wide range of illnesses. Most remedies are prepared as ethanol or aqueous extracts and then ingested. The aim of this study was to evaluate the potential toxicity of these extracts. The toxicity of ethanolic and water extracts of 341 plant species was determined using a brine-shrimp assay. Overall 24% of the species in water extract and 76% of the species in alcoholic extract showed elevated toxicity levels to brine-shrimp. Although in most cases multiple extracts of the same species showed very similar toxicity values, in some cases the toxicity of different extracts of the same species varied from non-toxic to highly toxic. Traditional preparation methods take different toxicity levels in aqueous and ethanol extracts into account when choosing the appropriate solvent for the preparation of a remedy. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

International Nuclear Information System (INIS)

Klobucar, Goeran I.V.; Stambuk, Anamaria; Srut, Maja; Husnjak, Ivana; Merkas, Martina; Traven, Luka; Cvetkovic, Zelimira

2011-01-01

There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Research highlights: → Native A. caliginosa has shown significant biological effect measured by the Comet and NRRT assays. → The Comet assay on A. caliginosa and E. fetida has shown to be of similar sensitivity as the NRRT assay. → A. caliginosa is a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Native populations of endogeic earthworm Aporrectodea caliginosa can be successfully applied in the genotoxicity field surveys using Comet assay.

Aporrectodea caliginosa, a suitable earthworm species for field based genotoxicity assessment?

Energy Technology Data Exchange (ETDEWEB)

Klobucar, Goeran I.V., E-mail: gklobuca@zg.biol.pmf.hr [Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb (Croatia); Stambuk, Anamaria; Srut, Maja [Department of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb (Croatia); Husnjak, Ivana [Ministry of Environmental Protection, Physical Planning and Construction, Ulica Republike Austrije 14, Zagreb (Croatia); Merkas, Martina [Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000 Zagreb (Croatia); Traven, Luka [Department of Environmental Medicine, Medical Faculty, University of Rijeka, Brace Branchetta 20a, 51000 Rijeka (Croatia); Teaching Institute of Public Health of the Primorsko-goranska County, Kresimirova 52a, 51000 Rijeka (Croatia); Cvetkovic, Zelimira [Department of Ecology, Institute of Public Health, Mirogojska c. 16, 10000 Zagreb (Croatia)

2011-04-15

There is a growing interest for the application of biomakers to field-collected earthworms. Therefore we have evaluated the usability of native populations of endogeic, widely distributed earthworm Aporrectodea caliginosa in the assessment of soil genotoxicity using the Comet assay. Validation of the Comet assay on earthworm coelomocytes has been established using commercially available Eisenia fetida exposed to copper, cadmium, and pentachlorophenol, along with A. caliginosa exposed to copper in a filter paper contact test. Neutral red retention time (NRRT) assay was conducted on copper exposed and field-collected earthworms. Significant DNA and lysosomal damage was measured using Comet and NRRT assays in native populations of A. caliginosa sampled from the polluted soils in the urban area in comparison to the earthworms from the reference site. The results of this study confirm the employment of A. caliginosa as a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Research highlights: > Native A. caliginosa has shown significant biological effect measured by the Comet and NRRT assays. > The Comet assay on A. caliginosa and E. fetida has shown to be of similar sensitivity as the NRRT assay. > A. caliginosa is a suitable species for the in situ soil toxicity and genotoxicity field surveys. - Native populations of endogeic earthworm Aporrectodea caliginosa can be successfully applied in the genotoxicity field surveys using Comet assay.

Antimicrobial activity and toxicity in vitro and in vivo of Equisetum hyemale extracts

Directory of Open Access Journals (Sweden)

Geisiany Maria de Queiroz

2014-09-01

Full Text Available Equisetum hyemale L, (Equisetaceae species is considered a medicinal plant used in the form of teas to combat infectious or inflammation diseases, presenting several compounds related to these actions, There are no extensive studies about the use against different microbial groups as well as for the toxicity, The objective of these studies was for the first time evaluated the antimicrobial activity against oral microorganisms and the in vitro and in vivo toxicity of 70% ethanol and methanol E, hyemale extracts, Antimicrobial activity assays were performed by broth microdilution technique to determine the Minimum Inhibitory Concentration (MIC and the cytoxicity was assayed in vitro and acute toxicity in vivo was performed with mice, The methanol extracts, showed better antimicrobial activity against oral microorganisms whit MIC of 0.5 mg/mL, Both extracts presented low cytotoxicity even in high concentrations and the 70% ethanol extract of E, hyemale did not present toxicity inducing significant alterations and/or death in mice, This results suggests that both extracts exhibits great potential to therapeutic applications.

In situ sonochemical reduction and direct functionalization of graphene oxide: A robust approach with thermal and biomedical applications.

Science.gov (United States)

Maktedar, Shrikant S; Mehetre, Shantilal S; Avashthi, Gopal; Singh, Man

2017-01-01

The rapid, robust, scalable and non-hazardous sonochemical approach for in situ reduction and direct functionalization of graphene oxide has been developed for non-toxic biomedical applications. The graphene oxide (GrO) was directly functionalized with tryptamine (TA) without using any hazardous acylating and coupling reagents. The reaction was completed within 20min. An impact of ultrasound was inferred for a direct functionalization with other conventional methods. The evolved electronic states were confirmed with near edge X-ray absorption fine structure (NEXAFS). The direct covalent functionalization and formation of f-(TA) GrO was proven with FTIR, 13 C solid state NMR, XPS, XRD, Raman' HRTEM, AFM and TGA. The total percentage weight loss in TGA confirms an enhanced thermal stability of f-(TA) GrO. The f-(TA) GrO was further explored for an investigation of in vitro antimicrobial activity to ensure the health and environmental safety. An outstanding antibacterial activity of f-(TA) GrO was found against gram positive Staphylococcus aureus at MIC 128mgmL -1 . It confirms a suitability of f-(TA) GrO for thermally stable antibacterial coating. The f-(TA) GrO showed 39.14-48.9% antioxidant activities, evaluated with 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. The inherent cytotoxicity of f-(TA) GrO was evaluated with SRB assay to living cells, MCF-7 and Vero. The estimated cell viabilities were >80% upon addition of f-(TA) GrO over a wide concentration range of 10-80μgmL -1 . The high cytocompatibility of f-(TA) GrO confirms the low toxicity and an excellent biocompatibility. The morphological effect on Vero cell line, evidently confirmed the biocompatibility of f-(TA) GrO. Therefore, f-(TA) GrO was emerged as an advanced functional biomaterial for thermal and biomedical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Reliability of plant root comet assay in comparison with human leukocyte comet assay for assessment environmental genotoxic agents.

Science.gov (United States)

Reis, Gabriela Barreto Dos; Andrade-Vieira, Larissa Fonseca; Moraes, Isabella de Campos; César, Pedro Henrique Souza; Marcussi, Silvana; Davide, Lisete Chamma

2017-08-01

Comet assay is an efficient test to detect genotoxic compounds based on observation of DNA damage. The aim of this work was to compare the results obtained from the comet assay in two different type of cells extracted from the root tips from Lactuca sativa L. and human blood. For this, Spent Pot Liner (SPL), and its components (aluminum and fluoride) were applied as toxic agents. SPL is a solid waste generated in industry from the aluminum mining and processing with known toxicity. Three concentrations of all tested solutions were applied and the damages observed were compared to negative and positive controls. It was observed an increase in the frequency of DNA damage for human leukocytes and plant cells, in all treatments. On human leukocytes, SPL induced the highest percentage of damage, with an average of 87.68%. For root tips cells of L. sativa the highest percentage of damage was detected for aluminum (93.89%). Considering the arbitrary units (AU), the average of nuclei with high levels of DNA fragmentation was significant for both cells type evaluated. The tested cells demonstrated equal effectiveness for detection of the genotoxicity induced by the SPL and its chemical components, aluminum and fluoride. Further, using a unique method, the comet assay, we proved that cells from root tips of Lactuca sativa represent a reliable model to detect DNA damage induced by genotoxic pollutants is in agreement of those observed in human leukocytes as model. So far, plant cells may be suggested as important system to assess the toxicological risk of environmental agents. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparison of Fluorescence In Situ Hybridization and Chromogenic In Situ Hybridization for Low and High Throughput HER2 Genetic Testing

Science.gov (United States)

Poulsen, Tim S.; Espersen, Maiken L. M.; Kofoed, Vibeke; Dabetic, Tanja; Høgdall, Estrid; Balslev, Eva

2013-01-01

The purpose was to evaluate and compare 5 different HER2 genetic assays with different characteristics that could affect the performance to analyze the human epidermal growth factor 2 (HER2) gene copy number under low and high throughput conditions. The study included 108 tissue samples from breast cancer patients with HER2 immunohistochemistry (IHC) results scored as 0/1+, 2+, and 3+. HER2 genetic status was analysed using chromogenic in situ hybridization (CISH) and fluorescence in situ hybridization (FISH). Scoring results were documented through digital image analysis. The cancer region of interest was identified from a serial H&E stained slide following tissue cores were transferred to a tissue microarrays (TMA). When using TMA in a routine flow, all patients will be tested for HER2 status with IHC followed by CISH or FISH, thereby providing individual HER2 results. In conclusion, our results show that the differences between the HER2 genetic assays do not have an effect on the analytic performance and the CISH technology is superior to high throughput HER2 genetic testing due to scanning speed, while the IQ-FISH may still be a choice for fast low throughput HER2 genetic testing. PMID:24383005

In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells

KAUST Repository

Zenger, Katharina; Dutta, Subhajit; Wolff, Horst; Genton, Marc G.; Kraus, Birgit

2015-01-01

Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones.

In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells

KAUST Repository

Zenger, Katharina

2015-07-19

Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones.

Impedimetric toxicity assay in microfluidics using free and liposome-encapsulated anticancer drugs

DEFF Research Database (Denmark)

Caviglia, Claudia; Zor, Kinga; Montini, Lucia

2015-01-01

In this work, we have developed a microfluidic cytotoxicity assay for a cell culture and detection platform, which enables both fluid handling and electrochemical/optical detection. The cytotoxic effect of anticancer drugs doxorubicin (DOX), oxaliplatin (OX) as well as OX-loaded liposomes, develo...

Effectiveness of bioremediation in reducing toxicity in oiled intertidal sediments

International Nuclear Information System (INIS)

Lee, K.; Tremblay, G.H.

1995-01-01

A 123-day field study was conducted with in situ enclosures to compare the effectiveness of bioremediation strategies based in inorganic and organic fertilizer additions to accelerate the biodegradation rates and reduce the toxicity of Venture trademark condensate stranded within sand-beach sediments. Comparison of the two fertilizer formulations with identical nitrogen and phosphorus concentrations showed that the organic fertilizer stimulated bacterial productivity within the oiled sediments to the greatest extent. However, detailed chemical analysis indicated that inorganic fertilizer additions were the most effective in enhancing condensate biodegradation rates. The Microtox reg-sign Solid-Phase Test (SPT) bioassay was determined to be sensitive to Venture Condensate in laboratory tests. Subsequent application of this procedure to oiled sediment in the field showed a reduction in sediment toxicity over time. However, the Microtox reg-sign bioassay procedure did not identify significant reductions in sediment toxicity following bioremediation treatment. An observed increase in toxicity following periodic additions of the organic fertilizer was attributed to rapid biodegradation rates of the fertilizer, which resulted in the production of toxic metabolic products

Comparative cytotoxic and genotoxic potential of 13 drinking water disinfection by-products using a microplate-based cytotoxicity assay and a developed SOS/umu assay.

Science.gov (United States)

Zhang, Shao-Hui; Miao, Dong-Yue; Tan, Li; Liu, Ai-Lin; Lu, Wen-Qing

2016-01-01

The implications of disinfection by-products (DBPs) present in drinking water are of public health concern because of their potential mutagenic, carcinogenic and other toxic effects on humans. In this study, we selected 13 main DBPs found in drinking water to quantitatively analyse their cytotoxicity and genotoxicity using a microplate-based cytotoxicity assay and a developed SOS/umu assay in Salmonella typhimurium TA1535/pSK1002. With the developed SOS/umu test, eight DBPs: 3-chloro-4-(dichloromethyl)-5-hydroxy-2[5H]-fura3-chloro-4-(dichloromethyl)-5-hydroxy-2-[5H]-furanone (MX), dibromoacetonitrile (DBN), iodoacetic acid (IA), bromochloroacetonitrile (BCN), bromoacetic acid (BA), trichloroacetonitrile (TCN), dibromoacetic acid (DBA) and dichloroacetic acid (DCA) were significantly genotoxic to S. typhimurium. Three DBPs: chloroacetic acid (CA), trichloroacetic acid (TCA) and dichloroacetonitrile (DCN) were weakly genotoxic, whereas the remaining DBPs: chloroacetonitrile (CN) and chloral hydrate (CH) were negative. The rank order in decreasing genotoxicity was as follows: MX > DBN > IA > BCN > BA > TCN > DBA > DCA > CA, TCA, DCN > CN, CH. MX was approximately 370 000 times more genotoxic than DCA. In the microplate-based cytotoxicity assay, cytotoxic potencies of the 13 DBPs were compared and ranked in decreasing order as follows: MX > IA > DBN > BCN > BA > TCN > DCN > CA > DCA > DBA > CN > TCA > CH. MX was approximately 19 200 times more cytotoxic than CH. A statistically significant correlation was found between cytotoxicity and genotoxicity of the 13 DBPs in S. typhimurium. Results suggest that microplate-based cytotoxicity assay and the developed SOS/umu assay are feasible tools for analysing the cytotoxicity and genotoxicity of DBPs, particularly for comparing their toxic intensities quantitatively. © The Author 2015. Published by Oxford University Press on behalf of the UK Environmental Mutagen Society. All rights reserved. For permissions, please e

Plumbagin Nanoparticles Induce Dose and pH Dependent Toxicity on Prostate Cancer Cells.

Science.gov (United States)

Nair, Harikrishnan A; Snima, K S; Kamath, Ravindranath C; Nair, Shantikumar V; Lakshmanan, Vinoth-Kumar

2015-01-01

Stable nano-formulation of Plumbagin nanoparticles from Plumbago zeylanica root extract was explored as a potential natural drug against prostate cancer. Size and morphology analysis by DLS, SEM and AFM revealed the average size of nanoparticles prepared was 100±50nm. In vitro cytotoxicity showed concentration and time dependent toxicity on prostate cancer cells. However, plumbagin crude extract found to be highly toxic to normal cells when compared to plumbagin nanoformulation, thus confirming nano plumbagin cytocompatibility with normal cells and dose dependent toxicity to prostate cells. In vitro hemolysis assay confirmed the blood biocompatibility of the plumbagin nanoparticles. In wound healing assay, plumbagin nanoparticles provided clues that it might play an important role in the anti-migration of prostate cancer cells. DNA fragmentation revealed that partial apoptosis induction by plumbagin nanoparticles could be expected as a potent anti-cancer effect towards prostate cancer.

An effective and economic system for the determination of biogas production in discontinuous assays; Sistema effectivo y economico parala determinacion de la produccion de biogas en ensayos en discontinuo

Energy Technology Data Exchange (ETDEWEB)

Ferrer, I.; Fornes, O.; Ferrer, O.; Gordillo, M. A.; Font, X.

2004-07-01

Methodology for the determination of anaerobic biodegradability or toxicity assays is well described in bibliography. However a certain lack of information exists regarding the experimental assembly for the realization of such assays. In this article the experimental setup is described in detail, as well as the cost of a system for the determination of biogas production in toxicity or biodegradability anaerobic assays. (Author) 10 refs.

Gamma aminobutyric acid radioreceptor assay: a confirmatory quantitative assay for toxaphene in environmental and biological samples

International Nuclear Information System (INIS)

Saleh, M.A.; Blancato, J.N.

1993-01-01

Toxaphene is a complex mixture of polychlorinated monoterpenes, and was found to be acutely and chronically toxic to aquatic and wild life and posed a carcinogenic risk to humans before its ban in 1982. However, it is still found in the environment due to its relative persistence with an estimated half life time of about 10 years in soils. Toxaphenes neurotoxicity is attributed to a few isomers with a mode of action through binding to the chloride channel of the gamma-aminobutyric acid (GABA) receptor ionophore complex. [ 35 S] tertiary butylbicyclophosphorothionate (TBPS) with specific activity higher than 60 Ci/mmole has a high binding affinity to the same sites and is now commercially available and can be used to label the GABA receptor for the development of radioreceptor assay technique. The GABA receptor was prepared by a sequence of ultra centrifugation and dialysis of mammalian (rats, cows, catfish and goats) brain homogenates. The receptor is then labeled with [ 35 S] TBPS and the assay was conducted by measuring the displacement of radioactivity following incubation with the sample containing the analytes. The assay is fast, sensitive and requires very little or no sample preparation prior to the analysis. (Author)

Testing of toxicity based methods to develop site specific clean up objectives - phase 1: Toxicity protocol screening and applicability

International Nuclear Information System (INIS)

Hamilton, H.; Kerr, D.; Thorne, W.; Taylor, B.; Zadnik, M.; Goudey, S.; Birkholz, D.

1994-03-01

A study was conducted to develop a cost-effective and practical protocol for using bio-assay based toxicity assessment methods for remediation of decommissioned oil and gas production, and processing facilities. The objective was to generate site-specific remediation criteria for contaminated sites. Most companies have used the chemical-specific approach which, however, did not meet the ultimate land use goal of agricultural production. The toxicity assessment method described in this study dealt with potential impairment to agricultural crop production and natural ecosystems. Human health concerns were not specifically addressed. It was suggested that chemical-specific methods should be used when human health concerns exist. . Results showed that toxicity tests will more directly identify ecological stress caused by site contamination than chemical-specific remediation criteria, which can be unnecessarily protective. 11 refs., 7 tabs., 6 figs

Acute toxicity and genotoxicity of fermented traditional medicine oyaksungi-san

Directory of Open Access Journals (Sweden)

Hwayong Park

2017-06-01

Conclusion: As a whole, no acute toxicity or genotoxicity were observed in all the assays examined. Therefore, fermented OY is considered to be a safe material that can be used for development of complementary and alternative medicine using bioconversion.

Discriminating modes of toxic action in mice using toxicity in BALB/c mouse fibroblast (3T3) cells.

Science.gov (United States)

Huang, Tao; Yan, Lichen; Zheng, Shanshan; Wang, Yue; Wang, Xiaohong; Fan, Lingyun; Li, Chao; Zhao, Yuanhui; Martyniuk, Christopher J

2017-12-01

The objective of this study was to determine whether toxicity in mouse fibroblast cells (3T3 cells) could predict toxicity in mice. Synthesized data on toxicity was subjected to regression analysis and it was observed that relationship of toxicities between mice and 3T3 cells was not strong (R 2  = 0.41). Inclusion of molecular descriptors (e.g. ionization, pKa) improved the regression to R 2  = 0.56, indicating that this relationship is influenced by kinetic processes of chemicals or specific toxic mechanisms associated to the compounds. However, to determine if we were able to discriminate modes of action (MOAs) in mice using the toxicities generated from 3T3 cells, compounds were first classified into "baseline" and "reactive" guided by the toxic ratio (TR) for each compound in mice. Sequence, binomial and recursive partitioning analyses provided strong predictions of MOAs in mice based upon toxicities in 3T3 cells. The correct classification of MOAs based on these methods was 86%. Nearly all the baseline compounds predicted from toxicities in 3T3 cells were identified as baseline compounds from the TR in mice. The incorrect assignment of MOAs for some compounds is hypothesized to be due to experimental uncertainty that exists in toxicity assays for both mice and 3T3 cells. Conversely, lack of assignment can also arise because some reactive compounds have MOAs that are different in mice compared to 3T3 cells. The methods developed here are novel and contribute to efforts to reduce animal numbers in toxicity tests that are used to evaluate risks associated with organic pollutants in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study on the toxic effects induced by different arsenicals in primary cultured rat astroglia

International Nuclear Information System (INIS)

Jin Yaping; Sun Guifan; Li Xin; Li Gexin; Lu Chunwei; Qu Long

2004-01-01

Arsenic toxicity is a global health problem affecting millions of people. The objectives of this study were to determine if the toxic effects on primary cultured rat astroglia would be induced by different arsenicals. Based on alamarBlue assay and the single cell gel electrophoresis (SCGE, comet assay), the cell viability and DNA damage in the cells exposed to different arsenicals were evaluated. Treatment of astroglia with methylated arsenicals, that is, pentavalent monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV), resulted in no obvious changes in cell viability and DNA damage at micromolar concentrations. However, treatment of astroglia with inorganic arsenicals, that is, arsenite and arsenate, caused decreased cell viability and increased DNA damage at micromolar levels, and showing a dose-related decrease in mean alamarBlue reduced rate and a dose-related increase in mean comet length. Our study is therefore highly suggestive for a link between inorganic exposure and cellular toxicity or DNA damage. Based on the results of this study, the toxic effects induced by arsenite were stronger than those induced by arsenate

Riboflavin ameliorates cisplatin induced toxicities under photoillumination.

Directory of Open Access Journals (Sweden)

Iftekhar Hassan

Full Text Available BACKGROUND: Cisplatin is an effective anticancer drug that elicits many side effects mainly due to induction of oxidative and nitrosative stresses during prolonged chemotherapy. The severity of these side effects consequently restricts its clinical use under long term treatment. Riboflavin is an essential vitamin used in various metabolic redox reactions in the form of flavin adenine dinucleotide and flavin mononucleotide. Besides, it has excellent photosensitizing property that can be used to ameliorate these toxicities in mice under photodynamic therapy. METHODS AND FINDINGS: Riboflavin, cisplatin and their combinations were given to the separate groups of mice under photoilluminated condition under specific treatment regime. Their kidney and liver were excised for comet assay and histopathological studies. Furthermore, Fourier Transform Infrared Spectroscopy of riboflavin-cisplatin combination in vitro was also conducted to investigate any possible interaction between the two compounds. Their comet assay and histopathological examination revealed that riboflavin in combination with cisplatin was able to protect the tissues from cisplatin induced toxicities and damages. Moreover, Fourier Transform Infrared Spectroscopy analysis of the combination indicated a strong molecular interaction among their constituent groups that may be assigned for the protective effect of the combination in the treated animals. CONCLUSION: Inclusion of riboflavin diminishes cisplatin induced toxicities which may possibly make the cisplatin-riboflavin combination, an effective treatment strategy under chemoradiotherapy in pronouncing its antineoplastic activity and sensitivity towards the cancer cells as compared to cisplatin alone.

ToxCast Profiling in a Human Stem Cell Assay for ...

Science.gov (United States)

Standard practice for assessing disruptions in embryogenesis involves testing pregnant animals of two species, typically rats and rabbits, exposed during major organogenesis and evaluated just prior to term. Under this design the major manifestations of developmental toxicity are observed as one or more apical endpoints including intrauterine death, fetal growth retardation, structural malformations and variations. Alternative approaches to traditional developmental toxicity testing have been proposed in the form of in vitro data (e.g., embryonic stem cells, zebrafish embryos, HTS assays) and in silico models (e.g., computational toxicology). To increase the diversity of assays used to assess developmental toxicity in EPA’s ToxCast program, we tested the chemicals in Stemina’s metabolomics-based platform that utilizes the commecrially available H9 human embryonic stem cell line. The devTOXqP dataset for ToxCast of high-quality based on replicate samples and model performance (82% balanced accuracy, 0.71 sensitivity and 1.00 specificity). To date, 136 ToxCast chemicals (12.8% of 1065 tested) were positive in this platform; 48 triggered the biomarker signal without any change in hESC viability and 88 triggered activity concurrent with effects on cell viability. Work is in progress to complete the STM dataset entry into the TCPL, compare data with results from zFish and mESC platforms, profile bioactivity (ToxCastDB), endpoints (ToxRefDB), chemotypes (DSSTox)

Hazard and risk assessment of human exposure to toxic metals using in vitro digestion assay

Directory of Open Access Journals (Sweden)

Hani A. Alhadrami

2016-10-01

Full Text Available Clean-up targets for toxic metals require that the site be “fit for purpose”. This means that targets are set with respect to defined receptors that reflect intended land-use. In this study, the likely threat of human exposure to toxic metals has been evaluated by simulating the human digestion process in vitro. The effects of key attributes (i.e. sample fraction size, pH, Kd and total metal concentrations on the bioavailability of Cu and Ni were also investigated. Total metal concentration was the key explanatory factor for Cu and Ni bioavailability. A comparative ranking of metal concentrations in the context of tolerable daily intakes for Cu and Ni confirmed that the pH has the greatest impact on metals bioavailability. Rapid screening of key attributes and total toxic metal doses can reveal the relative hazard imposed on human, and this approach should be considered when defining threshold values for human protection.

Assessment of sediments from Tiete River - toxicity and trace elements - from Salesopolis to Suzano counties, Sao Paulo, Brazil

International Nuclear Information System (INIS)

Alegre, Gabriel F.; Borrely, Sueli; Nascimento, Thuany M.; Favaro, Deborah I.T.

2009-01-01

In the present study, sediment samples from the Tiete River were evaluated for toxicity and trace metals (5 sampling sites). The studied region includes Salesopolis to Suzano and surroundings, a highly industrialized area. The study involved toxicity evaluation (sediment, elutriate and pore-water) and the distribution of some major, trace and rare earth elements on sediments. Multielemental analysis was carried out by instrumental neutron activation analysis (INAA) and total mercury by cold vapor atomic absorption technique (CV AAS). The concentration values obtained for the metals As, Cr, Hg and Zn in the sediment samples were compared to the Canadian Council of Minister of the Environment (CCME) oriented values (TEL and PEL). Regarding toxicity, whole sediments and elutriate fractions were evaluated using chronic assays for Ceriodaphnia dubia, while the pore water was carried out for Vibrio fischeri toxicity assays. These assays followed Brazilian Standardized Methods (ABNT). Whole sediments and elutriate evidenced negative biological effects, even at Salesopolis county, the control site (less impacted area). The worst effects were obtained at Mogi das Cruzes and Suzano counties (sampling stations 3 and 4). The elutriate fractions collected at the same stations showed acute toxicity in two of three samples (C. dubia). When pore water was evaluated, a toxicity gradient which increased as the river flowed through Mogi das Cruzes county was obtained. Regarding toxic metal contents in the sediment samples points 3 and 4 exceeded the TEL oriented values for As, Cr, Hg and Zn and point 4 also exceeded the PEL values for all these elements. (author)

Toxicity of middle distillates from dermal exposure.

Science.gov (United States)

Koschier, F J

1999-02-01

This report focuses on recent studies that investigated the effects of kerosine dermal exposure on neurotoxicity and reproductive/developmental toxicity. Background toxicity information will also be reviewed for kerosine range mid distillates. The kerosine range mid distillates have a carbon range of C9-C16 and have a boiling range of 302-554 degrees F (150-290 degrees C). This category includes kerosine, aviation fuels (e.g., Jet A, JP-5 and JP-8), no. 1 fuel oil and diesel fuel oil. In general, the kerosine range mid distillates demonstrate relatively low acute toxicity by any route of exposure. High inhalation exposures can induce central nervous system depression characterized by ataxia, hypoactivity and prostration. Kerosines are known to cause skin irritation and inflammation under conditions of acute and repeated exposure in animals and humans, but are only slightly irritating to the eye and are not skin sensitizers. In addition, the absorption of kerosine range mid distillates through the skin has been demonstrated to be fairly rapid, but limited to approximately 10-15% of the applied dose after 24 hours. The kerosine range mid distillates are generally inactive in genetic toxicity tests although positive studies have been reported. Positive results, while at times equivocal, have been reported for straight run kerosine and jet fuel A in the mouse lymphoma assay with metabolic activation, and hydrodesulfurized kerosine (mouse) and jet fuel A (rat) in the bone marrow cytogenetic assay. Effects on the nervous and reproductive systems have been reported in humans and experimental animals under conditions where inhalation and dermal exposure to specific kerosine type fuels are sometimes difficult to separate. Recent laboratory studies have addressed this point and examined the effects of dermal exposure. In these studies, rats were exposed to hydrodesulfurized kerosine by skin application to determine the potential of dermal contact to cause reproductive

Toxic effects exerted on methanogenic, nitrifying and denitrifying bacteria by chemicals used in a milk analysis laboratory

NARCIS (Netherlands)

Lopez-Fiuza, J.; Buys, B.; Mosquera-Corral, A.; Omil, F.; Mendez, R.

2002-01-01

The toxic effects caused by the chemicals contained in wastewaters generated by laboratories involved in raw milk analyses were assessed using batch assays. These assays were carried out separately with methanogenic, ammonium-oxidizing, nitrite-oxidizing and denitrifying bacteria. Since sodium azide

Gas Chromatography, GC/Mass Analysis and Bioactivity of Essential Oil from Aerial Parts of Ferulago trifida: Antimicrobial, Antioxidant, AChE Inhibitory, General Toxicity, MTT Assay and Larvicidal Activities.

Science.gov (United States)

Tavakoli, Saeed; Vatandoost, Hassan; Zeidabadinezhad, Reza; Hajiaghaee, Reza; Hadjiakhoondi, Abbas; Abai, Mohammad Reza; Yassa, Narguess

2017-09-01

We aimed to investigate different biological properties of aerial parts essential oil of Ferulago trifida Boiss and larvicidal activity of its volatile oils from all parts of plant. Essential oil was prepared by steam distillation and analyzed by Gas chromatography and GC/Mass. Antioxidant, antimicrobial, cytotoxic effects and AChE inhibitory of the oil were investigated using DPPH, disk diffusion method, MTT assay and Ellman methods. Larvicidal activity of F. trifida essential oil against malaria vector Anopheles stephensi was carried out according to the method described by WHO. In GC and GC/MS analysis, 58 compounds were identified in the aerial parts essential oil, of which E-verbenol (9.66%), isobutyl acetate (25.73%) and E-β-caryophyllene (8.68%) were main compounds. The oil showed (IC 50 = 111.2μg/ml) in DPPH and IC 50 = 21.5 mg/ml in the investigation of AChE inhibitory. Furthermore, the oil demonstrated toxicity with (LD 50 = 1.1μg/ml) in brine shrimp lethality test and with (IC 50 = 22.0, 25.0 and 42.55 μg/ml) on three cancerous cell lines (MCF-7, A-549 and HT-29) respectively. LC 50 of stem, root, aerial parts, fruits, and flowers essential oils against larvae of An. stephensi were equal with 10.46, 22.27, 20.50, 31.93 and 79.87ppm respectively. In antimicrobial activities, essential oil was effective on all specimens except Escherichia coli , Aspergillus niger and Candida albicans. The essential oil showed moderate antioxidant activity, strong antimicrobial properties and good toxic effect in brine shrimp test and MTT assay on three cancerous cell lines.

Non-specific phospholipase C4 mediates response to aluminum toxicity in Arabidopsis thaliana

Directory of Open Access Journals (Sweden)

Přemysl ePejchar

2015-02-01

Full Text Available Aluminum ions (Al have been recognized as a major toxic factor for crop production in acidic soils. The first indication of the Al toxicity in plants is the cessation of root growth, but the mechanism of root growth inhibition is largely unknown. Here we examined the impact of Al on the expression, activity and function of the non-specific phospholipase C4 (NPC4, a plasma membrane-bound isoform of NPC, a member of the plant phospholipase family, in Arabidopsis thaliana.We observed a lower expression of NPC4 using GUS assay and a decreased formation of labeled diacylglycerol, product of NPC activity, using fluorescently labeled phosphatidylcholine as a phospholipase substrate in Arabidopsis WT seedlings treated with AlCl3 for 2 h. The effect on in situ NPC activity persisted for longer Al treatment periods (8, 14 h. Interestingly, in seedlings overexpressing NPC4, the Al-mediated NPC-inhibiting effect was alleviated at 14 h. However, in vitro activity and localization of NPC4 were not affected by Al, thus excluding direct inhibition by Al ions or possible translocation of NPC4 as the mechanisms involved in NPC-inhibiting effect. Furthermore, the growth of tobacco pollen tubes rapidly arrested by Al was partially rescued by the overexpression of AtNPC4 while Arabidopsis npc4 knockout lines were found to be more sensitive to Al stress during long-term exposure of Al at low phosphate conditions.Our observations suggest that NPC4 plays a role in both early and long-term responses to Al stress.

Portable, accurate toxicity testing

International Nuclear Information System (INIS)

Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L.; Hinds, A.A.; Vieaux, G.J.

1994-01-01

Ever tightening environmental regulations, severe penalties for non-compliance, and expensive remediation costs have stimulated development of methods to detect and measure toxins. Most of these methods are bioassays that must be performed in the laboratory; none previously devised has been truly portable. The US Army, through the Small Business Innovative Research program, has developed a hand-held, field deployable unit for testing toxicity of battlefield water supplies. This patented system employs the measurable quenching, in the presence of toxins, of the natural bioluminescence produced by the marine dinoflagellate alga Pyrocystis lunula. The procedure's inventor used it for years to measure toxicity concentrations of chemical warfare agents actually, their simulants, primarily in the form of pesticides and herbicides plus assorted toxic reagents, waterbottom samples, drilling fluids, even blood. While the procedure is more precise, cheaper, and faster than most bioassays, until recently it was immobile. Now it is deployable in the field. The laboratory apparatus has been proven to be sensitive to toxins in concentrations as low as a few parts per billion, repeatable within a variation of 10% or less, and unlike some other bioassays effective in turbid or colored media. The laboratory apparatus and the hand-held tester have been calibrated with the EPA protocol that uses the shrimplike Mysidopsis bahia. The test organism tolerates transportation well, but must be rested a few hours at the test site for regeneration of its light-producing powers. Toxicity now can be measured confidently in soils, water columns, discharge points, and many other media in situ. Most significant to the oil industry is that drilling fluids can be monitored continuously on the rig

Towards non-invasive 3D hepatotoxicity assays with optical coherence phase microscopy

Science.gov (United States)

Nelson, Leonard J.; Koulovasilopoulos, Andreas; Treskes, Philipp; Hayes, Peter C.; Plevris, John N.; Bagnaninchi, Pierre O.

2015-03-01

Three-dimensional tissue-engineered models are increasingly recognised as more physiologically-relevant than standard 2D cell culture for pre-clinical drug toxicity testing. However, many types of conventional toxicity assays are incompatible with dense 3D tissues. This study investigated the use of optical coherence phase microscopy (OCPM) as a novel approach to assess cell death in 3D tissue culture. For 3D micro-spheroid formation Human hepatic C3A cells were encapsulated in hyaluronic acid gels and cultured in 100μl MEME/10%FBS in 96-well plates. After spheroid formation the 3D liver constructs were exposed to acetaminophen on culture day 8. Acetaminophen hepatotoxicity in 3D cultures was evaluated using standard biochemical assays. An inverted OCPM in common path configuration was developed with a Callisto OCT engine (Thorlabs), centred at 930nm and a custom scanning head. Intensity data were used to perform in-depth microstructural imaging. In addition, phase fluctuations were measured by collecting several successive B scans at the same location, and statistics on the first time derivative of the phase, i.e. time fluctuations, were analysed over the acquisition time interval to retrieve overall cell viability. OCPM intensity (cell cluster size) and phase fluctuation statistics were directly compared with biochemical assays. In this study, we investigated optical coherence phase tomography to assess cell death in a 3d liver model after exposure to a prototypical hepatotoxin, acetaminophen. We showed that OCPM has the potential to assess noninvasively and label-free drug toxicity in 3D tissue models.

In situ gelling dorzolamide loaded chitosan nanoparticles for the treatment of glaucoma.

Science.gov (United States)

Katiyar, Shefali; Pandit, Jayamanti; Mondal, Rabi S; Mishra, Anil K; Chuttani, Krishna; Aqil, Mohd; Ali, Asgar; Sultana, Yasmin

2014-02-15

The most important risk associated with glaucoma is the onset and progression of intraocular pressure. The objective of this study was to formulate in situ gel of chitosan nanoparticles to enhance the bioavailability and efficacy of dorzolamide in the glaucoma treatment. Optimized nanoparticles were spherical in shape (particle size: 164 nm) with a loading efficiency of 98.1%. The ex vivo release of the optimized in situ gel nanoparticle formulation showed a sustained drug release as compared to marketed formulation. The gamma scintigraphic study of prepared in situ nanoparticle gel showed good corneal retention compared to marketed formulation. HET-CAM assay of the prepared formulation scored 0.33 in 5 min which indicates the non-irritant property of the formulation. Thus in situ gel of dorzolamide hydrochloride loaded nanoparticles offers a more intensive treatment of glaucoma and a better patient compliance as it requires fewer applications per day compared to conventional eye drops. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of toxicity reduction of sodium dodecyl sulfate submitted to electron beam radiation

Science.gov (United States)

Romanelli, M. F.; Moraes, M. C. F.; Villavicencio, A. L. C. H.; Borrely, S. I.

2004-09-01

Surfactants, as detergent active substances, are an important source of pollution causing biological adverse effects to aquatic organisms. Several data have been showing ecological disturbance due to the high concentration of surfactants on receiving waters and on wastewater treatment plants. Ionizing radiation has been proved as an effective technology to decompose organic substances and few papers have included ecotoxicological aspects. This paper shows the reduction of acute toxicity of a specific surfactant, sodium dodecyl sulfate (SDS), when diluted in distilled water and submitted to electron beam radiation. The study included two test-organisms, the marine bacteria Vibrio fischeri and the crustacean Daphnia similis. Radiation processing resulted in an important acute toxicity removal for both assays, which can be summarized between 70% and 96%, using 3.0, 6.0, 9.0 and 12.0 kGy as radiation doses. Nevertheless, lower doses demonstrated better effect than 9.0 and 12.0 kGy and the bacterium assay was more sensitive to SDS than crustacean assay.

Complementing in vitro screening assays with in silico molecular chemistry tools to examine potential in vivo metabolite-mediated effects

Science.gov (United States)

High-throughput in vitro assays offer a rapid, cost-efficient means to screen thousands of chemicals across hundreds of pathway-based toxicity endpoints. However, one main concern involved with the use of in vitro assays is the erroneous omission of chemicals that are inactive un...

A novel comprehensive evaluation platform to assess nanoparticle toxicity in vitro

Science.gov (United States)

Hirsch, C.; Kaiser, J.-P.; Wessling, F.; Fischer, K.; Roesslein, M.; Wick, P.; Krug, H. F.

2011-07-01

The amount of engineered nanomaterials (ENM) is constantly increasing. Their unique properties, compared to their bulk counterparts, render them suitable for various applications in many areas of life. Hence, nanomaterials appear in a variety of different consumer products leading to the exposure of human beings and the environment during their lifecycle. Even though results on biological effects of ENM are available, harmonized and validated test systems are still missing. One major problem concerning the reliable and robust toxicity testing arises from interactions of ENM with different assay systems. Modifications or damage to DNA can have fatal consequences, such as the formation of tumor cells and hence carcinogenesis. Therefore we focused on the re-evaluation of two genotoxicity assays concerning their nanomaterial compatibility; namely the cytokinesis-block micronucleus cytome assay (MN-assay) and the alkaline single cell gel electorphoresis assay (comet assay). We demonstrate the interference of ENM agglomerates with the read-out of both assays and discuss possibilities how to acquire relevant genotoxicity data.

A novel comprehensive evaluation platform to assess nanoparticle toxicity in vitro

International Nuclear Information System (INIS)

Hirsch, C; Kaiser, J-P; Wessling, F; Fischer, K; Roesslein, M; Wick, P; Krug, H F

2011-01-01

The amount of engineered nanomaterials (ENM) is constantly increasing. Their unique properties, compared to their bulk counterparts, render them suitable for various applications in many areas of life. Hence, nanomaterials appear in a variety of different consumer products leading to the exposure of human beings and the environment during their lifecycle. Even though results on biological effects of ENM are available, harmonized and validated test systems are still missing. One major problem concerning the reliable and robust toxicity testing arises from interactions of ENM with different assay systems. Modifications or damage to DNA can have fatal consequences, such as the formation of tumor cells and hence carcinogenesis. Therefore we focused on the re-evaluation of two genotoxicity assays concerning their nanomaterial compatibility; namely the cytokinesis-block micronucleus cytome assay (MN-assay) and the alkaline single cell gel electorphoresis assay (comet assay). We demonstrate the interference of ENM agglomerates with the read-out of both assays and discuss possibilities how to acquire relevant genotoxicity data.

Genetic polymorphism in Gymnodinium galatheanum chloroplast DNA sequences and development of a molecular detection assay.

Science.gov (United States)

Tengs, T; Bowers, H A; Ziman, A P; Stoecker, D K; Oldach, D W

2001-02-01

Nuclear and chloroplast-encoded small subunit ribosomal DNA sequences were obtained from several strains of the toxic dinoflagellate Gymnodinium galatheanum. Phylogenetic analyses and comparison of sequences indicate that the chloroplast sequences show a higher degree of sequence divergence than the nuclear homologue. The chloroplast sequences were chosen as targets for the development of a 5'--3' exonuclease assay for detection of the organism. The assay has a very high degree of specificity and has been used to screen environmental water samples from a fish farm where the presence of this dinoflagellate species has previously been associated with fish kills. Various hypotheses for the derived nature of the chloroplast sequences are discussed, as well as what is known about the toxicity of the species.

Comparative metal oxide nanoparticle toxicity using embryonic zebrafish

Directory of Open Access Journals (Sweden)

Leah C. Wehmas

2015-01-01

Full Text Available Engineered metal oxide nanoparticles (MO NPs are finding increasing utility in the medical field as anticancer agents. Before validation of in vivo anticancer efficacy can occur, a better understanding of whole-animal toxicity is required. We compared the toxicity of seven widely used semiconductor MO NPs made from zinc oxide (ZnO, titanium dioxide, cerium dioxide and tin dioxide prepared in pure water and in synthetic seawater using a five-day embryonic zebrafish assay. We hypothesized that the toxicity of these engineered MO NPs would depend on physicochemical properties. Significant agglomeration of MO NPs in aqueous solutions is common making it challenging to associate NP characteristics such as size and charge with toxicity. However, data from our agglomerated MO NPs suggests that the elemental composition and dissolution potential are major drivers of toxicity. Only ZnO caused significant adverse effects of all MO particles tested, and only when prepared in pure water (point estimate median lethal concentration = 3.5–9.1 mg/L. This toxicity was life stage dependent. The 24 h toxicity increased greatly (∼22.7 fold when zebrafish exposures started at the larval life stage compared to the 24 h toxicity following embryonic exposure. Investigation into whether dissolution could account for ZnO toxicity revealed high levels of zinc ion (40–89% of total sample were generated. Exposure to zinc ion equivalents revealed dissolved Zn2+ may be a major contributor to ZnO toxicity.

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

Science.gov (United States)

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

2012-06-01

Reproductive toxicity testing is characterized by high animal use. For registration of pharmaceutical compounds, developmental toxicity studies are usually conducted in both rat and rabbits. Efforts have been underway for a long time to design alternatives to animal use. Implementation has lagged, partly because of uncertainties about the applicability domain of the alternatives. The reproductive cycle is complex and not all mechanisms of development can be mimicked in vitro. Therefore, efforts are underway to characterize the available alternative tests with regard to the mechanism of action they include. One alternative test is the mouse embryonic stem cell test (EST), which has been studied since the late 1990s. It is a genuine 3R "alternative" assay as it is essentially animal-free. A meeting was held to review the state-of-the-art of various in vitro models for prediction of developmental toxicity. Although the predictivity of individual assays is improving, a battery of several assays is likely to have even higher predictivity, which is necessary for regulatory acceptance. The workshop concluded that an important first step is a thorough survey of the existing rat and rabbit studies, to fully characterize the frequency of responses and the types of effects seen. At the same time, it is important to continue the optimization of in vitro assays. As more experience accumulates, the optimal conditions, assay structure, and applicability of the alternative assays are expected to emerge. Copyright © 2012 Elsevier Inc. All rights reserved.

Persistence and dioxin-like toxicity of carbazole and chlorocarbazoles in soil.

Science.gov (United States)

Mumbo, John; Henkelmann, Bernhard; Abdelaziz, Ahmed; Pfister, Gerd; Nguyen, Nghia; Schroll, Reiner; Munch, Jean Charles; Schramm, Karl-Werner

2015-01-01

Halogenated carbazoles have recently been detected in soil and water samples, but their environmental effects and fate are unknown. Eighty-four soil samples obtained from a site with no recorded history of pollution were used to assess the persistence and dioxin-like toxicity of carbazole and chlorocarbazoles in soil under controlled conditions for 15 months. Soil samples were divided into two temperature conditions, 15 and 20 °C, both under fluctuating soil moisture conditions comprising 19 and 44 drying-rewetting cycles, respectively. This was characterized by natural water loss by evaporation and rewetting to -15 kPa. Accelerated solvent extraction (ASE) and cleanup were performed after incubation. Identification and quantification were done using high-resolution gas chromatogram/mass spectrometer (HRGC/MS), while dioxin-like toxicity was determined by ethoxyresorufin-O-deethylase (EROD) induction in H4IIA rat hepatoma cells assay and multidimensional quantitative structure-activity relationships (mQSAR) modelling. Carbazole, 3-chlorocarbazole and 3,6-dichlorocarbazole were detected including trichlorocarbazole not previously reported in soils. Carbazole and 3-chlorocarbazole showed significant dissipation at 15 °C but not at 20 °C incubating conditions indicating that low temperature could be suitable for dissipation of carbazole and chlorocarbazoles. 3,6-Dichlorocarbazole was resistant at both conditions. Trichlorocarbazole however exhibited a tendency to increase in concentration with time. 3-Chlorocarbazole, 3,6-dibromocarbazole and selected soil extracts exhibited EROD activity. Dioxin-like toxicity did not decrease significantly with time, whereas the sum chlorocarbazole toxic equivalence concentrations (∑TEQ) did not contribute significantly to the soil assay dioxin-like toxicity equivalent concentrations (TCDD-EQ). Carbazole and chlorocarbazoles are persistent with the latter also toxic in natural conditions.

Toxicity assessment of organochlorine compounds detected in water environment using cultured human cell lines; Hito yurai saibo baiyokei wo mochiita suikankyo shiryochu no yuki enso kagobutsu no dokusei hyoka

Energy Technology Data Exchange (ETDEWEB)

Kunimoto, M; Yonemoto, J; Soma, Y; Nakasugi, O [National Institute for Environmental Studies, Tsukuba (Japan)

1997-11-10

As part of validation processes of in vitro toxicity assays for the risk assessment of environmental hazards, we applied an in vitro toxicity test using two human cell lines, neuroblastoma NB-1 cells and glioblastoma U-87 MG cells, to the assessment of organochlorine compounds detected in the water environment. The in vitro toxicity assay using NB-1 cells was calibrated by testing reference chemicals proposed by MEIC (Multicenter Evaluation of In Vitro Cytotoxicity), an international program for the validation of in vitro cytotoxicity assays. Beforehand, an assay using cells in frozen stock without subcultivation was examined by comparing IC50 values with the ordinary assay using subcultured cells. IC50 values for MEIC reference chemicals from the former assay showed good correlation with those from the latter assay, suggesting that the assay using cells in frozen stock can be used at least for the assessment of basal cytotoxicity. IC50 values for ten organochlorine compounds frequently detected in the sediment samples from contaminated rivers, p-chloroaniline, 3,4-dichloroaniline, p-dichlorobenzene, o-dichlorobenzene, Tris (2-chloroethyl)-phosphate, 2,5-dichlorophenol, 2,5-dichloroanisol, Triclosan and Triclocarban, were obtained with the in vitro assays and compared with their LD50 values in rats. No significant correlation, however, was seen between the IC50 and LD50 values, indicating that further improvement of in vitro toxicity assays is necessary for the application to the risk assessment of environmental hazards. 7 refs., 4 figs., 1 tab.

Tolerance to various toxicants by marine bacteria highly resistant to mercury

Digital Repository Service at National Institute of Oceanography (India)

De, J.; Ramaiah, N.; Mesquita, A.; Verlecar, X.N.

of growth in media containing 5 ppm mercury. Plasmid-curing assays done in this study ascertained that resistance to mercury antibiotics, and toxic xenobiotics is mediated by chromosomally borne genes and/or transposable elements rather than by plasmids...

A Comparison of Real-Time and Endpoint Cell Viability Assays for Improved Synthetic Lethal Drug Validation.

Science.gov (United States)

Single, Andrew; Beetham, Henry; Telford, Bryony J; Guilford, Parry; Chen, Augustine

2015-12-01

Cell viability assays fulfill a central role in drug discovery studies. It is therefore important to understand the advantages and disadvantages of the wide variety of available assay methodologies. In this study, we compared the performance of three endpoint assays (resazurin reduction, CellTiter-Glo, and nuclei enumeration) and two real-time systems (IncuCyte and xCELLigence). Of the endpoint approaches, both the resazurin reduction and CellTiter-Glo assays showed higher cell viabilities when compared directly to stained nuclei counts. The IncuCyte and xCELLigence real-time systems were comparable, and both were particularly effective at tracking the effects of drug treatment on cell proliferation at sub-confluent growth. However, the real-time systems failed to evaluate contrasting cell densities between drug-treated and control-treated cells at full growth confluency. Here, we showed that using real-time systems in combination with endpoint assays alleviates the disadvantages posed by each approach alone, providing a more effective means to evaluate drug toxicity in monolayer cell cultures. Such approaches were shown to be effective in elucidating the toxicity of synthetic lethal drugs in an isogenic pair of MCF10A breast cell lines. © 2015 Society for Laboratory Automation and Screening.

A multigene expression assay to predict local recurrence risk for ductal carcinoma in situ of the breast.

Science.gov (United States)

Solin, Lawrence J; Gray, Robert; Baehner, Frederick L; Butler, Steven M; Hughes, Lorie L; Yoshizawa, Carl; Cherbavaz, Diana B; Shak, Steven; Page, David L; Sledge, George W; Davidson, Nancy E; Ingle, James N; Perez, Edith A; Wood, William C; Sparano, Joseph A; Badve, Sunil

2013-05-15

For women with ductal carcinoma in situ (DCIS) of the breast, the risk of developing an ipsilateral breast event (IBE; defined as local recurrence of DCIS or invasive carcinoma) after surgical excision without radiation is not well defined by clinical and pathologic characteristics. The Oncotype DX breast cancer assay was performed for patients with DCIS treated with surgical excision without radiation in the Eastern Cooperative Oncology Group (ECOG) E5194 study. The association of the prospectively defined DCIS Score (calculated from seven cancer-related genes and five reference genes) with the risk of developing an IBE was analyzed using Cox regression. All statistical tests were two-sided. There were 327 patients with adequate tissue for analysis. The continuous DCIS Score was statistically significantly associated with the risk of developing an IBE (hazard ratio [HR] = 2.31, 95% confidence interval [CI] = 1.15 to 4.49; P = .02) when adjusted for tamoxifen use (prespecified primary analysis) and with invasive IBE (unadjusted HR = 3.68, 95% CI = 1.34 to 9.62; P = .01). For the prespecified DCIS risk groups of low, intermediate, and high, the 10-year risks of developing an IBE were 10.6%, 26.7%, and 25.9%, respectively, and for an invasive IBE, 3.7%, 12.3%, and 19.2%, respectively (both log rank P ≤ .006). In multivariable analyses, factors associated with IBE risk were DCIS Score, tumor size, and menopausal status (all P ≤ .02). The DCIS Score quantifies IBE risk and invasive IBE risk, complements traditional clinical and pathologic factors, and provides a new clinical tool to improve selecting individualized treatment for women with DCIS who meet the ECOG E5194 criteria.

Comet Assay on Daphnia magna in eco-genotoxicity testing.

Science.gov (United States)

Pellegri, Valerio; Gorbi, Gessica; Buschini, Annamaria

2014-10-01

Detection of potentially hazardous compounds in water bodies is a priority in environmental risk assessment. For the evaluation and monitoring of water quality, a series of methodologies may be applied. Among them, the worldwide used toxicity tests with organisms of the genus Daphnia is one of the most powerful. In recent years, some attempts were made to utilize Daphnia magna in genotoxicity testing as many of the new environmental contaminants are described as DNA-damaging agents in aquatic organisms. The aim of this research was to develop a highly standardized protocol of the Comet Assay adapted for D. magna, especially regarding the isolation of cells derived from the same tissue (haemolymph) from newborn organisms exposed in vivo. Several methods for haemolymph extraction and different Comet Assay parameters were compared. Electrophoretic conditions were adapted in order to obtain minimum DNA migration in cells derived from untreated organisms and, at the same time, maximum sensitivity in specimens treated with known genotoxicants (CdCl2 and H2O2). Additional tests were performed to investigate if life-history traits of the cladoceran (such as the age of adult organisms that provide newborns, the clutch size of origin, the number of generations reared in standard conditions) and the water composition as well, might influence the response of the assay. This study confirms the potential application of the Comet Assay in D. magna for assessing genotoxic loads in aqueous solution. The newly developed protocol could integrate the acute toxicity bioassay, thus expanding the possibility of using this model species in freshwater monitoring (waters, sediment and soil elutriates) and is in line with the spirit of the EU Water Framework Directive in reducing the number of bioassays that involve medium-sized species. Copyright © 2014 Elsevier B.V. All rights reserved.

In vitro structure-toxicity relationship of chalcones in human hepatic stellate cells.

Science.gov (United States)

Zenger, Katharina; Dutta, Subhajit; Wolff, Horst; Genton, Marc G; Kraus, Birgit

2015-10-02

Xanthohumol (XN), the major prenylated chalcone from hops (Humulus lupulus L.), has received much attention within the last years, due to its multiple pharmacological activities including anti-proliferative, anti-inflammatory, antioxidant, pro-apoptotic, anti-bacterial and anti-adhesive effects. However, there exists a huge number of metabolites and structurally-related chalcones, which can be expected, or are already known, to exhibit various effects on cells. We have therefore analyzed the effects of XN and 18 other chalcones in a panel, consisting of multiple cell-based assays. Readouts of these assays addressed distinct aspects of cell-toxicity, like proliferation, mitochondrial health, cell cycle and other cellular features. Besides known active structural elements of chalcones, like the Michael system, we have identified several moieties that seem to have an impact on specific effects and toxicity in human liver cells in vitro. Based on these observations, we present a structure-toxicity model, which will be crucial to understand the molecular mechanisms of wanted effects and unwanted side-effects of chalcones. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparison of central HER2 testing with quantitative total HER2 expression and HER2 homodimer measurements using a novel proximity-based assay.

Science.gov (United States)

Huang, Weidong; Reinholz, Monica; Weidler, Jodi; Yolanda, Lie; Paquet, Agnes; Whitcomb, Jeannette; Lingle, Wilma; Jenkins, Robert B; Chen, Beiyun; Larson, Jeffrey S; Tan, Yuping; Sherwood, Thomas; Bates, Michael; Perez, Edith A

2010-08-01

The accuracy and reliability of immunohistochemical analysis and in situ hybridization for the assessment of HER2 status remains a subject of debate. We developed a novel assay (HERmark Breast Cancer Assay, Monogram Biosciences, South San Francisco, CA) that provides precise quantification of total HER2 protein expression (H2T) and HER2 homodimers (H2D) in formalin-fixed, paraffin-embedded tissue specimens. H2T and H2D results of 237 breast cancers were compared with those of immunohistochemical studies and fluorescence in situ hybridization (FISH) centrally performed at the Mayo Clinic, Rochester, MN. H2T described a continuum across a wide dynamic range ( approximately 2.5 log). Excluding the equivocal cases, HERmark showed 98% concordance with immunohistochemical studies for positive and negative assay values. For the 94 immunohistochemically equivocal cases, 67% and 39% concordance values were observed between HERmark and FISH for positive and negative assay values, respectively. Polysomy 17 in the absence of HER2 gene amplification did not result in HER2 overexpression as evaluated quantitatively using the HERmark assay.

Latent Toxicity of Endothall to Anadromous Salmonids During Seawater Challenge.

Science.gov (United States)

Courter, Lauren A; Garrison, Thomas M; Courter, Ian I

2016-05-01

Limited evidence exists on the latent effects of toxicant exposure on the seawater adaptability of anadromous salmon and steelhead. It is unclear whether such an effect exists for the widely used and relatively non-toxic herbicide endothall. Coho salmon, Oncorhynchus kisutch (coho), Chinook salmon, O. tshawytscha (Chinook), and anadromous rainbow trout, O. mykiss (steelhead) were subjected to a 10-day seawater challenge following freshwater treatments [0-12 mg acid equivalent (a.e)./L at 96 h]. Mean survival resulted in 82 % (n = 225), 84 % (n = 133), 90 % (n = 73) and 59 % (n = 147) survival for 0, 3-5, 6-8, and 9-12 mg a.e./L, respectively. Our results indicate a lower toxicity threshold compared with previously reported acute toxicity results, but higher compared with previous seawater challenge studies. We demonstrate the utility of the seawater challenge assay to accurately define toxic effects of pesticides on salmonids with complex life-histories.

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

Energy Technology Data Exchange (ETDEWEB)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Ederli, L.; Pasqualini, S. [Department of Applied Biology, University of Perugia, I-06121 (Italy); Monarca, S. [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy); Moretti, M., E-mail: massimo.moretti@unipg.i [Department of Medical-Surgical Specialties and Public Health, University of Perugia, I-06126 (Italy)

2009-12-15

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

Assessing the genotoxicity of urban air pollutants using two in situ plant bioassays

International Nuclear Information System (INIS)

Villarini, M.; Fatigoni, C.; Dominici, L.; Maestri, S.; Ederli, L.; Pasqualini, S.; Monarca, S.; Moretti, M.

2009-01-01

Genotoxicity of urban air has been analysed almost exclusively in airborne particulates. We monitored the genotoxic effects of airborne pollutants in the urban air of Perugia (Central Italy). Two plant bioindicators with different genetic endpoints were used: micronuclei in meiotic pollen mother cells using Tradescantia-micronucleus bioassay (Trad-MCN) and DNA damage in nuclei of Nicotiana tabacum leaves using comet assay (Nicotiana-comet). Buds of Tradescantia clone no. 4430 and young N. tabacum cv. Xanthi plants were exposed for 24 h at three sites with different pollution levels. One control site (indoor control) was also used. The two bioassays showed different sensitivities toward urban pollutants: Trad-MCN assay was the most sensitive, but DNA damage in N. tabacum showed a better correlation with the pollutant concentrations. In situ biomonitoring of airborne genotoxins using higher plants combined with chemical analysis is thus recommended for characterizing genotoxicity of urban air. - Plant bioassays used to explore in situ the correlation between air pollution and genotoxicity.

In situ, dual-mode monitoring of organ-on-a-chip with smartphone-based fluorescence microscope.

Science.gov (United States)

Cho, Soohee; Islas-Robles, Argel; Nicolini, Ariana M; Monks, Terrence J; Yoon, Jeong-Yeol

2016-12-15

The use of organ-on-a-chip (OOC) platforms enables improved simulation of the human kidney's response to nephrotoxic drugs. The standard method of analyzing nephrotoxicity from existing OOC has majorly consisted of invasively collecting samples (cells, lysates, media, etc.) from an OOC. Such disruptive analyses potentiate contamination, disrupt the replicated in vivo environment, and require expertize to execute. Moreover, traditional analyses, including immunofluorescence microscopy, immunoblot, and microplate immunoassay are essentially not in situ and require substantial time, resources, and costs. In the present work, the incorporation of fluorescence nanoparticle immunocapture/immunoagglutination assay into an OOC enabled dual-mode monitoring of drug-induced nephrotoxicity in situ. A smartphone-based fluorescence microscope was fabricated as a handheld in situ monitoring device attached to an OOC. Both the presence of γ-glutamyl transpeptidase (GGT) on the apical brush-border membrane of 786-O proximal tubule cells within the OOC surface, and the release of GGT to the outflow of the OOC were evaluated with the fluorescence scatter detection of captured and immunoagglutinated anti-GGT conjugated nanoparticles. This dual-mode assay method provides a novel groundbreaking tool to enable the internal and external in situ monitoring of the OOC, which may be integrated into any existing OOCs to facilitate their subsequent analyses. Copyright © 2016 Elsevier B.V. All rights reserved.

Assay to detect lipid peroxidation upon exposure to nanoparticles.

Science.gov (United States)

Potter, Timothy M; Neun, Barry W; Stern, Stephan T

2011-01-01

This chapter describes a method for the analysis of human hepatocarcinoma cells (HEP G2) for lipid peroxidation products, such as malondialdehyde (MDA), following treatment with nanoparticle formulations. Oxidative stress has been identified as a likely mechanism of nanoparticle toxicity, and cell-based in vitro systems for evaluation of nanoparticle-induced oxidative stress are widely considered to be an important component of biocompatibility screens. The products of lipid peroxidation, lipid hydroperoxides, and aldehydes, such as MDA, can be measured via a thiobarbituric acid reactive substances (TBARS) assay. In this assay, which can be performed in cell culture or in cell lysate, MDA combines with thiobarbituric acid (TBA) to form a fluorescent adduct that can be detected at an excitation wavelength of 530 nm and an emission wavelength of 550 nm. The results are then expressed as MDA equivalents, normalized to total cellular protein (determined by Bradford assay).

Functional toxicology: tools to advance the future of toxicity testing

Science.gov (United States)

Gaytán, Brandon D.; Vulpe, Chris D.

2014-01-01

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

Future directions for in-situ product removal (ISPR)

DEFF Research Database (Denmark)

Woodley, John; Bisschops, Marc; Straathof, Adrie J J

2008-01-01

by inhibitory or toxic products, as wen as unstable products or reactions that are thermodynamically unfavorable. However, several issues for industrial implementation were revealed in the discussion. Most notably implementation will be dependent on (1) research into the appropriate process structure, (2......This paper summarizes the main findings of a round-table discussion held to examine the key bottlenecks in the further application and industrial implementation of in-situ product removal (ISPR) techniques. It is well established that ISPR can yield great benefits for processes limited...

Novel RNA hybridization method for the in situ detection of ETV1, ETV4, and ETV5 gene fusions in prostate cancer.

Science.gov (United States)

Kunju, Lakshmi P; Carskadon, Shannon; Siddiqui, Javed; Tomlins, Scott A; Chinnaiyan, Arul M; Palanisamy, Nallasivam

2014-09-01

The genetic basis of 50% to 60% of prostate cancer (PCa) is attributable to rearrangements in E26 transformation-specific (ETS) (ERG, ETV1, ETV4, and ETV5), BRAF, and RAF1 genes and overexpression of SPINK1. The development and validation of reliable detection methods are warranted to classify various molecular subtypes of PCa for diagnostic and prognostic purposes. ETS gene rearrangements are typically detected by fluorescence in situ hybridization and reverse-transcription polymerase chain reaction methods. Recently, monoclonal antibodies against ERG have been developed that detect the truncated ERG protein in immunohistochemical assays where staining levels are strongly correlated with ERG rearrangement status by fluorescence in situ hybridization. However, specific antibodies for ETV1, ETV4, and ETV5 are unavailable, challenging their clinical use. We developed a novel RNA in situ hybridization-based assay for the in situ detection of ETV1, ETV4, and ETV5 in formalin-fixed paraffin-embedded tissues from prostate needle biopsies, prostatectomy, and metastatic PCa specimens using RNA probes. Further, with combined RNA in situ hybridization and immunohistochemistry we identified a rare subset of PCa with dual ETS gene rearrangements in collisions of independent tumor foci. The high specificity and sensitivity of RNA in situ hybridization provides an alternate method enabling bright-field in situ detection of ETS gene aberrations in routine clinically available PCa specimens.

Acute toxicity and genotoxicity study of fermented traditional herb formula Guibi-tang.

Science.gov (United States)

Park, Hwayong; Hwang, Youn-Hwan; Yang, Hye Jin; Kim, Hyun-Kyu; Song, Kyung Seuk; Ma, Jin Yeul

2014-10-28

Guibi-tang (Guipi-tang in Chinese and Kihi-to in Japanese) is a multi-herb traditional medicine commonly prescribed to treat psychoneurosis in East Asia. Although this medicine has been widely used, there is little available information on the safety and toxicity of Guibi-tang, especially on the fermented one. Guibi-tang, composed of 12 herbs, was fermented with bacteria and lyophilized. Single dose acute toxicity in rats was observed for 14 days after administration. Genetic toxicity of fermented Guibi-tang was evaluated on bacterial reverse mutation in Salmonella and Escherichia spp., chromosome aberrations in Chinese hamster ovary cells, and micronucleus formation in mice. Ingredients in FGBT were identified and quantified by high performance liquid chromatography-mass spectrometry. In acute oral toxicity study, behavior, clinical signs and body weight changes were normal observing in all experimental animals. No revertant colonies were found in any bacterial cultures examined. Morphological or numerical anomalies and significant increased number of aberrant metaphases were not observed. Micronucleus assay showed no significant increases in the frequency of inducing micronuclei in any dose examined. Decursinol, decursin, glycyrrhizin, and 6-gingerol in fermented Guibi-tang were identified and quantitated. As a whole, no acute and genotoxic effects were found in all the assays and parameters analyzed. Fermented Guibi-tang was recognized as safe and non-toxic, and therefore can be used for applications of traditional medicine in modern complementary and alternative therapeutics and health care. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

ToxCast Workflow: High-throughput screening assay data processing, analysis and management (SOT)

Science.gov (United States)

US EPA’s ToxCast program is generating data in high-throughput screening (HTS) and high-content screening (HCS) assays for thousands of environmental chemicals, for use in developing predictive toxicity models. Currently the ToxCast screening program includes over 1800 unique c...

Solid-phase receptor-based assay for the detection of cyclic imines by chemiluminescence, fluorescence, or colorimetry.

Science.gov (United States)

Rodríguez, Laura P; Vilariño, Natalia; Molgó, Jordi; Aráoz, Rómulo; Antelo, Alvaro; Vieytes, Mercedes R; Botana, Luis M

2011-08-01

The spirolides and gymnodimines are marine phycotoxins included in the group of cyclic imines. The toxicity of these compounds to humans is still unknown, although their toxicity by intraperitoneal injection in rodents is very high. A receptor-based method was developed using the competition of the 13-desmethyl spirolide C with biotin-labeled α-bungarotoxin for binding to nicotinic acetylcholine receptors and the immobilization of the α-bungarotoxin-receptor complex on streptavidin-coated surfaces. The quantification of the immobilized receptor can be achieved using a specific antibody. Finally, after the addition of a secondary antibody labeled with horseradish peroxidase, three alternative substrates of this enzyme generate a chemiluminescent, fluorescent, or colorimetric signal. The assay performs well in shellfish extracts and the detection range is 5-150 nM of 13-desmethyl spirolide C in shellfish extracts, which is at least 5 times more sensitive than the existing fluorescence polarization assay. This assay can also detect gymnodimine, although with 10 times lower sensitivity than the spirolide. The detection of cyclic imines with microplate assays would be useful for screening purposes in order to reduce the number of samples to be processed by bioassays or analytical methods.

Ecotoxicological evaluation of leachate from the Limeira sanitary landfill with a view to identifying acute toxicity

OpenAIRE

José Euclides Stipp Paterniani; Ronaldo Teixeira Pelegrini; Núbia Natália de Brito Pelegrini

2007-01-01

Final disposal of solid waste is still a cause for serious impacts on the environment. In sanitary landfills, waste undergoes physical, chemical, and biological decomposition, generating biogas and leachate. Leachate is a highly toxic liquid with a very high pollution potential. The purpose of this work is to evaluate toxicity of in natura leachate samples collected from Limeira Sanitary Landfill, in Limeira, SP. The ecotoxicological evaluation comprised acute toxicity assays using as test or...

Comet Assay: A Method to Evaluate Genotoxicity of Nano-Drug Delivery System

Science.gov (United States)

Vandghanooni, Somayeh; Eskandani, Morteza

2011-01-01

Introduction Drug delivery systems could induce cellular toxicity as side effect of nanomaterials. The mechanism of toxicity usually involves DNA damage. The comet assay or single cell gel electrophoresis (SCGE) is a sensitive method for detecting strand damages in the DNA of a cell with applications in genotoxicity testing and molecular epidemiology as well as fundamental research in DNA damage and repair. Methods In the current study, we reviewed recent drug delivery researches related to SCGE. Results We found that one preference for choosing the assay is that comet images may result from apoptosis-mediated nuclear fragmentation. This method has been widely used over the last decade in several different areas. Overall cells, such as cultured cells are embedded in agarose on a microscope slide, lysed with detergent, and treated with high salt. Nucleoids are supercoiled DNA form. When the slide is faced to alkaline electrophoresis any breakages present in the DNA cause the supercoiling to relax locally and loops of DNA extend toward the anode as a ‘‘comet tail’’. Conclusion This article provides a relatively comprehensive review upon potentiality of the comet assay for assessment of DNA damage and accordingly it can be used as an informative platform in genotoxicity studies of drug delivery systems. PMID:23678412

Toxicity assessment of carbon black waste: A by-product from oil refineries

Energy Technology Data Exchange (ETDEWEB)

Zhen, Xu; Ng, Wei Cheng [NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602 (Singapore); Fendy; Tong, Yen Wah [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Dai, Yanjun [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai, 200240 (China); Neoh, Koon Gee, E-mail: chenkg@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore); Wang, Chi-Hwa, E-mail: chewch@nus.edu.sg [Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585 (Singapore)

2017-01-05

Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

Toxicity assessment of carbon black waste: A by-product from oil refineries

International Nuclear Information System (INIS)

Zhen, Xu; Ng, Wei Cheng; Fendy; Tong, Yen Wah; Dai, Yanjun; Neoh, Koon Gee; Wang, Chi-Hwa

2017-01-01

Highlights: • Carbon black waste extract decreased cell viability in a dose and time-dependent manner. • Apoptosis of human cell lines was induced by carbon black waste extract. • Carbon black waste extract elicited oxidative stress by increasing intracellular ROS generation. • Carbon black waste extract impaired antioxidant enzymatic activities of human cell lines. • The high toxicity of carbon black waste extract could be attributed mainly to the effect of vanadium. - Abstract: In Singapore, approximately 30 t/day of carbon-based solid waste are produced from petrochemical processes. This carbon black waste has been shown to possess physical properties that are characteristic of a good adsorbent such as high external surface area. Therefore, there is a growing interest to reutilize and process this carbon black waste into secondary materials such as adsorbents. However, the carbon black waste obtained from petrochemical industries may contain heavy metals that are hazardous to human health and the environment, hence restricting its full potential for re-utilization. Therefore, it is important to examine the possible toxicity effects and toxicity mechanism of carbon black waste on human health. In this study, inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis showed that the heavy metals, vanadium (V), molybdenum (Mo) and nickel (Ni), were present in the carbon black waste in high concentrations. Three human cell lines (HepG2 cells, MRC-5 cells and MDA-MB-231 cells) were used to investigate the toxicity of carbon black waste extract in a variety of in vitro assays. Results from MTS assays indicated that carbon black waste extract decreased the viability of all three cell lines in a dose and time-dependent manner. Observations from confocal microscopy further confirmed this phenomenon. Flow cytometry assay also showed that carbon black waste extract induced apoptosis of human cell lines, and the level of apoptosis increased with

Effects of heat-activated persulfate oxidation on soil microorganisms

DEFF Research Database (Denmark)

Tsitonaki, Aikaterini; Smets, Barth F.; Bjerg, Poul Løgstrup

2008-01-01

/L). The results emphasize the necessity of using multiple toxicity assays and indigenous cultures in order to realistically assess the potential effects of in situ chemical oxidation on soil microorganisms. A comparison to other studies suggests that the effects of activated persulfate on soil microorganisms...

Antioxidant Capacity, Cytotoxicity, and Acute Oral Toxicity of Gynura bicolor

Directory of Open Access Journals (Sweden)

Wuen Yew Teoh

2013-01-01

Full Text Available Gynura bicolor (Compositae which is widely used by the locals as natural remedies in folk medicine has limited scientific studies to ensure its efficacy and nontoxicity. The current study reports the total phenolic content, antioxidant capacity, cytotoxicity, and acute oral toxicity of crude methanol and its fractionated extracts (hexane, ethyl acetate, and water of G. bicolor leaves. Five human colon cancer cell lines (HT-29, HCT-15, SW480, Caco-2, and HCT 116, one human breast adenocarcinoma cell line (MCF7, and one human normal colon cell line (CCD-18Co were used to evaluate the cytotoxicity of G. bicolor. The present findings had clearly demonstrated that ethyl acetate extract of G. bicolor with the highest total phenolic content among the extracts showed the strongest antioxidant activity (DPPH radical scavenging assay and metal chelating assay, possessed cytotoxicity, and induced apoptotic and necrotic cell death, especially towards the HCT 116 and HCT-15 colon cancer cells. The acute oral toxicity study indicated that methanol extract of G. bicolor has negligible level of toxicity when administered orally and has been regarded as safe in experimental rats. The findings of the current study clearly established the chemoprevention potential of G. bicolor and thus provide scientific validation on the therapeutic claims of G. bicolor.

In silico assessment of the acute toxicity of chemicals: recent advances and new model for multitasking prediction of toxic effect.

Science.gov (United States)

Kleandrova, Valeria V; Luan, Feng; Speck-Planche, Alejandro; Cordeiro, M Natália D S

2015-01-01

The assessment of acute toxicity is one of the most important stages to ensure the safety of chemicals with potential applications in pharmaceutical sciences, biomedical research, or any other industrial branch. A huge and indiscriminate number of toxicity assays have been carried out on laboratory animals. In this sense, computational approaches involving models based on quantitative-structure activity/toxicity relationships (QSAR/QSTR) can help to rationalize time and financial costs. Here, we discuss the most significant advances in the last 6 years focused on the use of QSAR/QSTR models to predict acute toxicity of drugs/chemicals in laboratory animals, employing large and heterogeneous datasets. The advantages and drawbacks of the different QSAR/QSTR models are analyzed. As a contribution to the field, we introduce the first multitasking (mtk) QSTR model for simultaneous prediction of acute toxicity of compounds by considering different routes of administration, diverse breeds of laboratory animals, and the reliability of the experimental conditions. The mtk-QSTR model was based on artificial neural networks (ANN), allowing the classification of compounds as toxic or non-toxic. This model correctly classified more than 94% of the 1646 cases present in the whole dataset, and its applicability was demonstrated by performing predictions of different chemicals such as drugs, dietary supplements, and molecules which could serve as nanocarriers for drug delivery. The predictions given by the mtk-QSTR model are in very good agreement with the experimental results.

Discrimination of uranium chemo-toxic and radio-toxic effects: definition of biological markers for evaluating professional risks in nuclear industry

International Nuclear Information System (INIS)

Darolles, Carine

2010-01-01

Uranium (U) is a heavy metal that is also considered as an alpha emitter. Thus the origin of U toxicity is both chemical and radiological. The identification of bio-markers to discriminate chemical and radiological toxicity for a given U compound is required to assess accurately the health effects of isotopic mixtures such as depleted U in 235 U with a low specific activity. Data from the literature show that the best candidates are cytogenetic markers. In the present work, the assessment of bio-markers of U contamination was performed on three cellular models (mouse fibroblasts, rat lymphocytes and human lymphocytes) that were exposed to different isotopic mixtures of U. The cytokinesis-block micronucleus (MN) centromere assay was performed to discriminate the chemo-toxic and radio-toxic effects of U. This study showed that the evaluation of micronuclei in bi-nucleated cells could not assess U genotoxicity accurately. Instead, the assessment of centromere-negative micronuclei and nucleo-plasmic bridges correlated with the radio-toxic effects of U. The evaluation of centromere-positive micronuclei and micronuclei in mono-nucleated cells correlated with the chemo-toxic effects of U. These cytogenetic markers should be validated on different biological models and could be proposed to discriminate radiological and chemical toxicity of a given isotopic mixture of U. These four cytogenetic markers could be a useful complement of the classical dosimetric bio-markers for the assessment of internal uranium contamination. (author)

Exposure to contaminated sediments induces alterations in the gill epithelia in juvenile Solea senegalensis: a comparative in situ and ex situ study

Directory of Open Access Journals (Sweden)

Carla Martins

2014-06-01

Full Text Available The loss of biodiversity in aquatic ecosystems is a major problem for society, with very significant ecological and economic deleterious effects. Estuaries, as the Sado Estuary (SW Portugal, are fragile ecosystems always associated to multiple anthropogenic stressors, such as heavy industry, shipping and agricultural activities, which can affect biodiversity and, therefore, environmental health, as well as the local economy, through its impact on fisheries. In the Sado Estuary there are many important commercial fish species that support a significant part of the local communities. As such, fish population are continuously exposed to pollutants that can have repercussions in the animals’ physiology and survival. This estuary is characterized by its multiple sources of toxicants, which is reflected onto a complex pattern of sediment contamination. In order to evaluate the physiological effects onto an important commercial species in the Sado Estuary, juvenile Solea senegalensis were subjected to a series of in and ex situ sediment-based bioassays, since this flatfish, being benthic, is particularly exposed to sediment-bound pollutants. Histological alterations in gill epithelia were taken as the main endpoint, since this is the main apical entry organ of toxicants. Sediment contaminants, mostly adsorbed to fine particles and organic matter, namely organochlorides, PAHs and same metals, presented a relation with alterations in gill epithelia. Even though no significant gross histopathological lesions were found, the animals exposed to sediments from the most polluted sites presented physiological alterations, when compared to those exposed to sediments from a reference site. These alterations were particularly related to the number of mucous cells and hypertrophied chloride cells per interlamellar space. These changes imply physiological hampering of normal gill functions and, therefore, affect the health status of animals exposed to

Toxicity evaluation of the process effluent streams of a petrochemical industry.

Science.gov (United States)

Reis, J L R; Dezotti, M; Sant'Anna, G L

2007-02-01

The physico-chemical characteristics and the acute toxicity of several wastewater streams, generated in the industrial production of synthetic rubber, were determined. The acute toxicity was evaluated in bioassays using different organisms: Danio rerio (fish), Lactuca sativa (lettuce) and Brachionus calyciflorus (rotifer). The removal of toxicity attained in the industrial wastewater treatment plant was also determined upstream and downstream of the activated sludge process. The results obtained indicate that the critical streams in terms of acute toxicity are the effluents from the liquid polymer unit and the spent caustic butadiene washing stage. The biological treatment was able to partially remove the toxicity of the industrial wastewater. However, a residual toxicity level persisted in the biotreated wastewater. The results obtained with Lactuca sativa showed a high degree of reproducibility, using root length or germination index as evaluation parameters. The effect of volatile pollutants on the toxicity results obtained with lettuce seeds was assessed, using ethanol as a model compound. Modifications on the assay procedure were proposed. A strong correlation between the toxic responses of Lactuca sativa and Danio rerio was observed for most industrial effluent streams.

Gas Chromatography, GC/Mass Analysis and Bioactivity of Essential Oil from Aerial Parts of Ferulago trifida: Antimicrobial, Antioxidant, AChE Inhibitory, General Toxicity, MTT assay and Larvicidal Activities

Directory of Open Access Journals (Sweden)

Saeed Tavakoli

2017-10-01

Full Text Available Background: We aimed to investigate different biological properties of aerial parts essential oil of Ferulago trifida Boiss and larvicidal activity of its volatile oils from all parts of plant.Methods: Essential oil was prepared by steam distillation and analyzed by Gas chromatography and GC/Mass. Anti­oxidant, antimicrobial, cytotoxic effects and AChE inhibitory of the oil were investigated using DPPH, disk diffusion method, MTT assay and Ellman methods. Larvicidal activity of F. trifida essential oil against malaria vector Anoph­eles stephensi was carried out according to the method described by WHO.Results: In GC and GC/MS analysis, 58 compounds were identified in the aerial parts essential oil, of which E-ver­benol (9.66%, isobutyl acetate (25.73% and E-β-caryophyllene (8.68% were main compounds. The oil showed (IC50= 111.2µg/ml in DPPH and IC50= 21.5 mg/ml in the investigation of AChE inhibitory. Furthermore, the oil demonstrated toxicity with (LD50= 1.1µg/ml in brine shrimp lethality test and with (IC50= 22.0, 25.0 and 42.55 µg/ml on three cancerous cell lines (MCF-7, A-549 and HT-29 respectively. LC50 of stem, root, aerial parts, fruits, and flowers essential oils against larvae of An. stephensi were equal with 10.46, 22.27, 20.50, 31.93 and 79.87ppm respectively. In antimicrobial activities, essential oil was effective on all specimens except Escherichia coli, Asper­gillus niger and Candida albicans.Conclusion: The essential oil showed moderate antioxidant activity, strong antimicrobial properties and good toxic effect in brine shrimp test and MTT assay on three cancerous cell lines.

Evaluation of the systemic toxicity and mutagenicity of OLIGOPIN®, procyanidolic oligomers (OPC) extracted from French Maritime Pine Bark extract.

Science.gov (United States)

Segal, L; Penman, M G; Piriou, Y

2018-01-01

The potential systemic toxicity of Oligopin®, a French Maritime Pine Bark extract (FMPBE) rich in procyanidolic oligomers, was evaluated in an acute oral limit test and a 90-day repeated dose oral toxicity study with Sprague Dawley rats. The potential mutagenicity was assessed in a bacterial reverse mutation assay and in vitro mammalian chromosome aberration assay with human lymphocytes. The results indicate that Oligopin® was nongenotoxic in both bacterial and human cell assays, was not acutely toxic via oral administration at up to 2000 mg/kg and was well tolerated following 90 days of oral administration to SD rats, with a no observed adverse effect level of 1000 mg/kg/day. The lack of significant adverse systemic effects in the 90 day study is concordant with findings from several human clinical trials. The acute toxicity and mutagenicity data are consistent with data reported by AFSSA in a summary of FMPBE safety, in which a NOAEL of 100 mg/kg/day was established. In contrast, the NOAEL derived from the 90-day study with Oligopin® was 1000 mg/kg/day, suggesting that it is less systemically toxic than other FMPBE previously evaluated in subchronic studies, and comparable to proanthocyanidins extracted from grape seeds, which are widely used as nutritional supplement ingredients.

Abrin Toxicity and Bioavailability after Temperature and pH Treatment.

Science.gov (United States)

Tam, Christina C; Henderson, Thomas D; Stanker, Larry H; He, Xiaohua; Cheng, Luisa W

2017-10-13

Abrin, one of most potent toxins known to man, is derived from the rosary pea (jequirity pea), Abrus precatorius and is a potential bioterror weapon. The temperature and pH stability of abrin was evaluated with an in vitro cell free translation (CFT) assay, a Vero cell culture cytotoxicity assay, and an in vivo mouse bioassay. pH treatment of abrin had no detrimental effect on its stability and toxicity as seen either in vitro or in vivo. Abrin exposure to increasing temperatures did not completely abrogate protein translation. In both the cell culture cytotoxicity model and the mouse bioassay, abrin's toxic effects were completely abrogated if the toxin was exposed to temperatures of 74 °C or higher. In the cell culture model, 63 °C-treated abrin had a 30% reduction in cytotoxicity which was validated in the in vivo mouse bioassay with all mice dying but with a slight time-to-death delay as compared to the non-treated abrin control. Since temperature inactivation did not affect abrin's ability to inhibit protein synthesis (A-chain), we hypothesize that high temperature treatment affected abrin's ability to bind to cellular receptors (affecting B-chain). Our results confirm the absolute need to validate in vitro cytotoxicity assays with in vivo mouse bioassays.

Injectible candidate sealants for fetal membrane repair: Bonding and toxicity in vitro

Science.gov (United States)

Bilic, Grozdana; Brubaker, Carrie; Messersmith, Phillip B.; Mallik, Ajit S.; Quinn, Thomas M.; Haller, Claudia; Done, Elisa; Gucciardo, Leonardo; Zeisberger, Steffen M.; Zimmermann, Roland; Deprest, Jan; Zisch, Andreas H.

2010-01-01

Objective This study was undertaken to test injectible surgical sealants that are biocompatible with fetal membranes, eventually for closure of iatrogenic membrane defects. Study Design Dermabond, Histoacryl, Tissucol fibrin glue, and three types of in situ forming poly(ethylene glycol)-based polymer hydrogels were tested for acute toxicity upon direct contact with fetal membranes for 24h. For determination of elution toxicity, extracts of sealants were incubated on amnion cell cultures for 72h. Bonding and toxicity was assessed through morphological and/or biochemical analysis. Results Extracts of all adhesives were non-toxic for cultured cells. However, only Tissucol and one type of poly(ethylene glycol)-based hydrogel, mussel-mimetic tissue adhesive, showed efficient, non-disruptive, non-toxic bonding to fetal membranes. Mussel-mimetic tissue adhesive applied over membrane defects created with a 3.5 mm trocar accomplished leak-proof closure that withstood membrane stretch in an in vitro model. Conclusion A synthetic hydrogel-type tissue adhesive emerged as potential sealing modality for iatrogenic membrane defects that merits further evaluation in vivo. PMID:20096254

Evaluation of environmental genotoxicity by comet assay in Columba livia.

Science.gov (United States)

González-Acevedo, Anahi; García-Salas, Juan A; Gosálvez, Jaime; Fernández, José Luis; Dávila-Rodríguez, Martha I; Cerda-Flores, Ricardo M; Méndez-López, Luis F; Cortés-Gutiérrez, Elva I

2016-01-01

The concentrations of recognized or suspected genotoxic and carcinogenic agents found in the air of large cities and, in particular, developing countries, have raised concerns about the potential for chronic health effects in the populations exposed to them. The biomonitoring of environmental genotoxicity requires the selection of representative organisms as "sentinels," as well as the development of suitable and sensitive assays, such as those aimed at assessing DNA damage. The aim of this study was to evaluate DNA damage levels in erythrocytes from Columba livia living in the metropolitan area of Monterrey, Mexico, compared with control animals via comet assay, and to confirm the results via Micronuclei test (MN) and DNA breakage detection-fluorescence in situ hybridization (DBD-FISH). Our results showed a significant increase in DNA migration in animals from the area assayed compared with that observed in control animals sampled in non-contaminated areas. These results were confirmed by MN test and DBD-FISH. In conclusion, these observations confirm that the examination of erythrocytes from Columba livia via alkaline comet assay provides a sensitive and reliable end point for the detection of environmental genotoxicants.

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African Journals Online (AJOL)

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Large-scale assessment of the zebrafish embryo as a possible predictive model in toxicity testing.

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Shaukat Ali

Full Text Available 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 LC(50 determination. Zebrafish embryo LC(50 (log mmol/L, and published data on rodent LD(50 (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.

Assessment of pyrrolizidine alkaloid-induced toxicity in an in vitro screening model.

Science.gov (United States)

Li, Yan Hong; Kan, Winnie Lai Ting; Li, Na; Lin, Ge

2013-11-25

Pyrrolizidine alkaloids (PAs) are a group of heterocyclic phytotoxins present in a wide range of plants. The consumption of PA-containing medicinal herbs or PA-contaminated foodstuffs has long been reported to cause human hepatotoxicity. However, the degrees of hepatotoxicity of different PAs are unknown, which makes it difficult to determine a universal threshold of toxic dose of individual PAs for safe regulation of PA-containing natural products. The aim of the present study is to develop a simple and convenient in vitro model to assess the hepatotoxicity of different PAs. Six common cytotoxicity assays were used to evaluate the hepatotoxicity of different PAs in human hepatocellular carcinoma HepG2 cells. The combination of MTT and bromodeoxyuridine incorporation (BrdU) assays demonstrated to be a suitable method to evaluate the toxic potencies of various PAs in HepG2 cells, and the results indicated that otonecine-type PA (clivorine: IC₂₀=0.013 ± 0.004 mM (MTT), 0.066 ± 0.031 mM (BrdU)) exhibited significantly higher cytotoxic and anti-proliferative effects than retronecine-type PA (retrorsine: IC₂₀=0.27 ± 0.07 mM (MTT), 0.19 ± 0.03 mM (BrdU)). While as expected, the known less toxic platyphylline-type PA (platyphylline: IC₂₀=0.85 ± 0.11 mM (MTT), 1.01 ± 0.40 mM (BrdU)) exhibited significantly less toxicity. The different cytotoxic and anti-proliferative potencies of various PAs in the same retronecine-type could also be discriminated by using the combined MTT and BrdU assays. In addition, the developed assays were further utilized to test alkaloid extract of Gynura segetum, a senecionine and seneciphylline-containing herb, the overall cytotoxicity of two PAs in the extract was comparable to that of these two PAs tested individually. Using the developed in vitro model, the cytotoxicity of different PAs and the extract of a PA-containing herb were investigated in parallel in one system, and their different hepatotoxic potencies were determined

USING STRUCTURAL EFFECTS ON THE ORGANIZATION OF THE CYTOSKELETON OF RAINBOW TROUT HEPATOCYTES TO SORT PATHWAYS OF REACTIVE TOXICITY

Science.gov (United States)

Quinones have been shown to be more acutely toxic to aquatic organisms than chemicals that are not capable of either direct interaction with cellular nucleophiles or potentially metabolized free radicals. For the development of accurate QSAR models, in vitro toxicity assays are n...

Rapid determination of the toxicity of quantum dots with luminous bacteria

Energy Technology Data Exchange (ETDEWEB)

Wang Lingling [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, No. 2 Tiansheng Road, Beibei District, Chongqing 400715 (China); Zheng Huzhi, E-mail: zhenghz@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, No. 2 Tiansheng Road, Beibei District, Chongqing 400715 (China); Long Yijuan; Gao Mei; Hao Jianyu; Du Juan; Mao Xiaojiao; Zhou Dongbo [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, No. 2 Tiansheng Road, Beibei District, Chongqing 400715 (China)

2010-05-15

In this paper, a novel method so-called bioluminescence inhibition assay with luminous bacteria (Photobacterium phosphoreum) was introduced to evaluate the toxicity of quantum dots. The bioassay was based on measuring the decrease of the light emitted by luminous bacteria. With obvious advantages of simplicity, rapidity and sensitivity, it can dramatically improve the efficiency of probing the toxicity of QDs. Based on this method, we systemically explored the effect of the composition and surface modification on QDs' toxicity. The experiment of composition effect was performed using three kinds of QDs, namely CdSe, CdTe and ZnS-AgInS{sub 2} QDs with the same stabilizer - dihydrolipoic acid. As for the effect of different stabilizers, mercaptoacetic acid, L-cysteine and dihydrolipoic acid stabilized CdSe were researched, respectively. Our results demonstrated that both the composition and surface modification were the important factors affecting the toxicity of QDs. In addition, a concentration dependence of toxicity was also found.

Rapid determination of the toxicity of quantum dots with luminous bacteria

International Nuclear Information System (INIS)

Wang Lingling; Zheng Huzhi; Long Yijuan; Gao Mei; Hao Jianyu; Du Juan; Mao Xiaojiao; Zhou Dongbo

2010-01-01

In this paper, a novel method so-called bioluminescence inhibition assay with luminous bacteria (Photobacterium phosphoreum) was introduced to evaluate the toxicity of quantum dots. The bioassay was based on measuring the decrease of the light emitted by luminous bacteria. With obvious advantages of simplicity, rapidity and sensitivity, it can dramatically improve the efficiency of probing the toxicity of QDs. Based on this method, we systemically explored the effect of the composition and surface modification on QDs' toxicity. The experiment of composition effect was performed using three kinds of QDs, namely CdSe, CdTe and ZnS-AgInS 2 QDs with the same stabilizer - dihydrolipoic acid. As for the effect of different stabilizers, mercaptoacetic acid, L-cysteine and dihydrolipoic acid stabilized CdSe were researched, respectively. Our results demonstrated that both the composition and surface modification were the important factors affecting the toxicity of QDs. In addition, a concentration dependence of toxicity was also found.

Whole cell based electrical impedance sensing approach for a rapid nanotoxicity assay

Energy Technology Data Exchange (ETDEWEB)

Hondroulis, Evangelia; Liu Chang; Li Chenzhong, E-mail: licz@fiu.edu [Nanobioengineering/Bioelectronics Laboratory, Department of Biomedical Engineering, Florida International University, 10555 West Flagler Street, Miami, FL 33174 (United States)

2010-08-06

A whole cell based biosensor for rapid real-time testing of human and environmental toxicity of nanoscale materials is reported. Recent studies measuring nanoparticle cytotoxicity in vitro provide a final measurement of toxicity to a cell culture overlooking the ongoing cytotoxic effects of the nanoparticles over the desired timeframe. An array biosensor capable of performing multiple cytotoxicity assays simultaneously was designed to address the need for a consistent method to measure real-time assessments of toxicity. The impedimetric response of human lung fibroblasts (CCL-153) and rainbow trout gill epithelial cells (RTgill-W1) when exposed to gold and silver nanoparticles (AuNPs, AgNPs), single walled carbon nanotubes (SWCNTs) and cadmium oxide (CdO) was tested. Exposure to CdO particles exhibited the fastest rate of cytotoxicity and demonstrated the biosensor's ability to monitor toxicity instantaneously in real time. Advantages of the present method include shorter run times, easier usage, and multi-sample analysis leading to a method that can monitor the kinetic effects of nanoparticle toxicity continuously over a desired timeframe.

Whole cell based electrical impedance sensing approach for a rapid nanotoxicity assay

Science.gov (United States)

Hondroulis, Evangelia; Liu, Chang; Li, Chen-Zhong

2010-08-01

A whole cell based biosensor for rapid real-time testing of human and environmental toxicity of nanoscale materials is reported. Recent studies measuring nanoparticle cytotoxicity in vitro provide a final measurement of toxicity to a cell culture overlooking the ongoing cytotoxic effects of the nanoparticles over the desired timeframe. An array biosensor capable of performing multiple cytotoxicity assays simultaneously was designed to address the need for a consistent method to measure real-time assessments of toxicity. The impedimetric response of human lung fibroblasts (CCL-153) and rainbow trout gill epithelial cells (RTgill-W1) when exposed to gold and silver nanoparticles (AuNPs, AgNPs), single walled carbon nanotubes (SWCNTs) and cadmium oxide (CdO) was tested. Exposure to CdO particles exhibited the fastest rate of cytotoxicity and demonstrated the biosensor's ability to monitor toxicity instantaneously in real time. Advantages of the present method include shorter run times, easier usage, and multi-sample analysis leading to a method that can monitor the kinetic effects of nanoparticle toxicity continuously over a desired timeframe.

Whole cell based electrical impedance sensing approach for a rapid nanotoxicity assay

International Nuclear Information System (INIS)

Hondroulis, Evangelia; Liu Chang; Li Chenzhong

2010-01-01

A whole cell based biosensor for rapid real-time testing of human and environmental toxicity of nanoscale materials is reported. Recent studies measuring nanoparticle cytotoxicity in vitro provide a final measurement of toxicity to a cell culture overlooking the ongoing cytotoxic effects of the nanoparticles over the desired timeframe. An array biosensor capable of performing multiple cytotoxicity assays simultaneously was designed to address the need for a consistent method to measure real-time assessments of toxicity. The impedimetric response of human lung fibroblasts (CCL-153) and rainbow trout gill epithelial cells (RTgill-W1) when exposed to gold and silver nanoparticles (AuNPs, AgNPs), single walled carbon nanotubes (SWCNTs) and cadmium oxide (CdO) was tested. Exposure to CdO particles exhibited the fastest rate of cytotoxicity and demonstrated the biosensor's ability to monitor toxicity instantaneously in real time. Advantages of the present method include shorter run times, easier usage, and multi-sample analysis leading to a method that can monitor the kinetic effects of nanoparticle toxicity continuously over a desired timeframe.

Fluorescence in situ hybridization for phytoplasma and endophytic bacteria localization in plant tissues.

Science.gov (United States)

Bulgari, Daniela; Casati, Paola; Faoro, Franco

2011-11-01

In the present study, we developed a rapid and efficient fluorescence in situ hybridization assay (FISH) in non-embedded tissues of the model plant Catharanthus roseus for co-localizing phytoplasmas and endophytic bacteria, opening new perspectives for studying the interaction between these microorganisms. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative hazard analysis and toxicological modeling of diverse nanomaterials using the embryonic zebrafish (EZ) metric of toxicity

International Nuclear Information System (INIS)

Harper, Bryan; Thomas, Dennis; Chikkagoudar, Satish; Baker, Nathan; Tang, Kaizhi; Heredia-Langner, Alejandro; Lins, Roberto; Harper, Stacey

2015-01-01

The integration of rapid assays, large datasets, informatics, and modeling can overcome current barriers in understanding nanomaterial structure–toxicity relationships by providing a weight-of-the-evidence mechanism to generate hazard rankings for nanomaterials. Here, we present the use of a rapid, low-cost assay to perform screening-level toxicity evaluations of nanomaterials in vivo. Calculated EZ Metric scores, a combined measure of morbidity and mortality in developing embryonic zebrafish, were established at realistic exposure levels and used to develop a hazard ranking of diverse nanomaterial toxicity. Hazard ranking and clustering analysis of 68 diverse nanomaterials revealed distinct patterns of toxicity related to both the core composition and outermost surface chemistry of nanomaterials. The resulting clusters guided the development of a surface chemistry-based model of gold nanoparticle toxicity. Our findings suggest that risk assessments based on the size and core composition of nanomaterials alone may be wholly inappropriate, especially when considering complex engineered nanomaterials. Research should continue to focus on methodologies for determining nanomaterial hazard based on multiple sub-lethal responses following realistic, low-dose exposures, thus increasing the availability of quantitative measures of nanomaterial hazard to support the development of nanoparticle structure–activity relationships

Comparative hazard analysis and toxicological modeling of diverse nanomaterials using the embryonic zebrafish (EZ) metric of toxicity

Energy Technology Data Exchange (ETDEWEB)

Harper, Bryan [Oregon State University (United States); Thomas, Dennis; Chikkagoudar, Satish; Baker, Nathan [Pacific Northwest National Laboratory (United States); Tang, Kaizhi [Intelligent Automation, Inc. (United States); Heredia-Langner, Alejandro [Pacific Northwest National Laboratory (United States); Lins, Roberto [CPqAM, Oswaldo Cruz Foundation, FIOCRUZ-PE (Brazil); Harper, Stacey, E-mail: stacey.harper@oregonstate.edu [Oregon State University (United States)

2015-06-15

The integration of rapid assays, large datasets, informatics, and modeling can overcome current barriers in understanding nanomaterial structure–toxicity relationships by providing a weight-of-the-evidence mechanism to generate hazard rankings for nanomaterials. Here, we present the use of a rapid, low-cost assay to perform screening-level toxicity evaluations of nanomaterials in vivo. Calculated EZ Metric scores, a combined measure of morbidity and mortality in developing embryonic zebrafish, were established at realistic exposure levels and used to develop a hazard ranking of diverse nanomaterial toxicity. Hazard ranking and clustering analysis of 68 diverse nanomaterials revealed distinct patterns of toxicity related to both the core composition and outermost surface chemistry of nanomaterials. The resulting clusters guided the development of a surface chemistry-based model of gold nanoparticle toxicity. Our findings suggest that risk assessments based on the size and core composition of nanomaterials alone may be wholly inappropriate, especially when considering complex engineered nanomaterials. Research should continue to focus on methodologies for determining nanomaterial hazard based on multiple sub-lethal responses following realistic, low-dose exposures, thus increasing the availability of quantitative measures of nanomaterial hazard to support the development of nanoparticle structure–activity relationships.

Evaluation of water column and sediment toxicity from an abandoned uranium mine using a battery of bioassays

International Nuclear Information System (INIS)

Antunes, S.C.; Figueiredo, D.R. de; Marques, S.M.; Castro, B.B.; Pereira, R.; Goncalves, F.

2007-01-01

Uranium mining activities in Cunha Baixa, Mangualde (Portugal), were extensive between 1967 and 1993, with high production of poor ore. Ore exploitation left millions of tons of tailings in the surrounding area, close to human houses. Contamination of the area (water and soil compartment) presently represents a serious hazard to humans and wildlife. The aim of this work was to evaluate the acute toxicity of water and sediments from a pond that floods a uranium mine pit, in two periods (spring and autumn). High contents of metals were found in water samples (chiefly Mn, Fe, Al, U, Sr). A battery of assays was applied to screen the acute toxicity of the different compartments using algae, crustaceans and dipterans. Results showed that the sediments were non-toxic, unlike the superficial water. Water toxicity was higher in the autumn, when the effluent was more acidic, compared to spring. In the water toxicity assays, the relative sensitivity of the test species used was Daphnia longispina > Pseudokirchneriella subcapitata > Daphnia magna. The present study is part of the chemical and ecotoxicological characterisation of the aquatic compartment performed in the Tier 1 of the Ecological Risk Assessment of the Cunha Baixa mining area

Fluorescent bioassays for toxic metals in milk and yoghurt

Science.gov (United States)

2012-01-01

Background From a human health viewpoint, contaminated milk and its products could be a source of long-term exposure to toxic metals. Simple, inexpensive, and on-site assays would enable constant monitoring of their contents. Bioassays that can measure toxic metals in milk or yoghurt might reduce the risk. For this purpose, the green fluorescent protein (GFP)-tagged trans factors, ArsR-GFP and CadC-GFP, together with their cis elements were used to develop such bioassays. Results ArsR-GFP or CadC-GFP, which binds either toxic metal or DNA fragment including cis element, was directly mixed with cow’s milk or yoghurt within a neutral pH range. The fluorescence of GFP, which is reflected by the association/dissociation ratio between cis element and trans factor, significantly changed with increasing externally added As (III) or Cd (II) whereas smaller responses to externally added Pb (II) and Zn (II) were found. Preparation and dilution of whey fraction at low pH were essential to intrinsic zinc quantification using CadC-GFP. Using the extraction procedure and bioassay, intrinsic Zn (II) concentrations ranging from 1.4 to 4.8 mg/l for milk brands and from 1.2 to 2.9 mg/kg for yoghurt brands were determined, which correlated to those determined using inductively coupled plasma atomic emission spectroscopy. Conclusions GFP-tagged bacterial trans factors and cis elements can work in the neutralized whole composition and diluted whey fraction of milk and yoghurt. The feature of regulatory elements is advantageous for establishment of simple and rapid assays of toxic metals in dairy products. PMID:23098077

Fluorescent bioassays for toxic metals in milk and yoghurt

Directory of Open Access Journals (Sweden)

Siddiki Mohammad Shohel

2012-10-01

Full Text Available Abstract Background From a human health viewpoint, contaminated milk and its products could be a source of long-term exposure to toxic metals. Simple, inexpensive, and on-site assays would enable constant monitoring of their contents. Bioassays that can measure toxic metals in milk or yoghurt might reduce the risk. For this purpose, the green fluorescent protein (GFP-tagged trans factors, ArsR-GFP and CadC-GFP, together with their cis elements were used to develop such bioassays. Results ArsR-GFP or CadC-GFP, which binds either toxic metal or DNA fragment including cis element, was directly mixed with cow’s milk or yoghurt within a neutral pH range. The fluorescence of GFP, which is reflected by the association/dissociation ratio between cis element and trans factor, significantly changed with increasing externally added As (III or Cd (II whereas smaller responses to externally added Pb (II and Zn (II were found. Preparation and dilution of whey fraction at low pH were essential to intrinsic zinc quantification using CadC-GFP. Using the extraction procedure and bioassay, intrinsic Zn (II concentrations ranging from 1.4 to 4.8 mg/l for milk brands and from 1.2 to 2.9 mg/kg for yoghurt brands were determined, which correlated to those determined using inductively coupled plasma atomic emission spectroscopy. Conclusions GFP-tagged bacterial trans factors and cis elements can work in the neutralized whole composition and diluted whey fraction of milk and yoghurt. The feature of regulatory elements is advantageous for establishment of simple and rapid assays of toxic metals in dairy products.

Microfluorometric mithramycin assay for quantitating the effects of immunotoxicants on lymphocyte activation

International Nuclear Information System (INIS)

Quattrone, A.J.; Ranney, D.F.

1981-01-01

A semiautomated, microfluorometric assay has been developed for the detection of toxicant-induced changes in lymphocyte DNA content at standard intervals after mitogen activation. DNA is quantitated by solubilizing the cells and determining the fluorescence enhancement that results from formation of the highly specific mithramycin:DNA adduct. The limit of detection is 0.21 μg (30,000 resting cell equivalents) per microliter well. Correlation with the less sensitive, nonautomatable, diphenylamine DNA assay give a correlation coefficient r = 0.91. Prototype substances representative of true immunotoxicants (prostaglandin E 2 ) and common interfering substances (thymidine at 14 M) have been tested. The latter substance produces false positive results in the standard [ 3 H] thymidine assay. The mithramycin assay does not inappropriately detect this interfering substance. It has the characteristics of a highly specific, accurate technique of screening and quantitating immunotoxic drugs, agents, and mediators in patient sera and other complex biological fluids

QIAD assay for quantitating a compound’s efficacy in elimination of toxic Aβ oligomers

Science.gov (United States)

Brener, Oleksandr; Dunkelmann, Tina; Gremer, Lothar; van Groen, Thomas; Mirecka, Ewa A.; Kadish, Inga; Willuweit, Antje; Kutzsche, Janine; Jürgens, Dagmar; Rudolph, Stephan; Tusche, Markus; Bongen, Patrick; Pietruszka, Jörg; Oesterhelt, Filipp; Langen, Karl-Josef; Demuth, Hans-Ulrich; Janssen, Arnold; Hoyer, Wolfgang; Funke, Susanne A.; Nagel-Steger, Luitgard; Willbold, Dieter

2015-01-01

Strong evidence exists for a central role of amyloid β-protein (Aβ) oligomers in the pathogenesis of Alzheimer’s disease. We have developed a fast, reliable and robust in vitro assay, termed QIAD, to quantify the effect of any compound on the Aβ aggregate size distribution. Applying QIAD, we studied the effect of homotaurine, scyllo-inositol, EGCG, the benzofuran derivative KMS88009, ZAβ3W, the D-enantiomeric peptide D3 and its tandem version D3D3 on Aβ aggregation. The predictive power of the assay for in vivo efficacy is demonstrated by comparing the oligomer elimination efficiency of D3 and D3D3 with their treatment effects in animal models of Alzheimer´s disease. PMID:26394756

A new DPYD genotyping assay for improving the safety of 5-fluorouracil therapy.

Science.gov (United States)

Sistonen, Johanna; Smith, Chingying; Fu, Yung-Kang; Largiadèr, Carlo R

2012-12-24

Chemotherapeutic use of 5-fluorouracil (5FU) is compromised by 10-20% of patients developing severe toxicity. Recently described genetic variation in dihydropyrimidine dehydrogenase (DPYD) has been shown to be a major predictor of 5FU toxicity. Here, we describe a new genotyping assay for routine clinical use that covers all the major DPYD risk variants. Genomic regions targeting DPYD risk variants (c.1129-5923C>G, c.1679T>G/A, c.1905+1G>A, c.2846A>T) and additional markers (c.234-123G>C, c.496A>G, c.775A>G) were amplified in a multiplex PCR reaction. The subsequent steps including allele-specific primer extension, hybridization of the primers to a microarray, scanning of the array, and data analysis were automated within the INFINITI® Analyzer (AutoGenomics). The assay was validated by analyzing 107 blood samples obtained from patients previously re-sequenced for the DPYD. The genotypes obtained with the developed assay were 100% concordant with the re-sequencing. The procedure is suitable for routine clinical use since the results are obtained within one day. For heterozygous risk variant carriers (~7% of Europeans), the treatment can be adjusted by 5FU dose reduction, whereas carriers of two risk alleles should be treated with an alternative therapy. The developed assay provides a novel tool to improve the safety of commonly used 5FU-based chemotherapies. Copyright © 2012 Elsevier B.V. All rights reserved.

Soil quality in the Lomellina area using in vitro models and ecotoxicological assays

Energy Technology Data Exchange (ETDEWEB)

Baderna, Diego, E-mail: diego.baderna@marionegri.it [Laboratory of Environmental Chemistry and Toxicology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Colombo, Andrea [Laboratory of Environmental Chemistry and Toxicology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Romeo, Margherita [Department of Molecular Biochemistry and Pharmacology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Cambria, Felice; Teoldi, Federico; Lodi, Marco [Laboratory of Environmental Chemistry and Toxicology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Diomede, Luisa [Department of Molecular Biochemistry and Pharmacology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Benfenati, Emilio [Laboratory of Environmental Chemistry and Toxicology, IRCCS—Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy)

2014-08-15

Soil quality is traditionally evaluated by chemical characterization to determine levels of pollutants. Biological tools are now employed for soil monitoring since they can take account of the global biological effects induced by all xenobiotics. A combined monitoring of soils based on chemical analyses, human-related in vitro models and ecotoxicological assay was applied in the Lomellina, a semirural area of northern Italy. Chemical characterization indicated overall good quality of the soils, with low levels of toxic and carcinogenic pollutants such as heavy metals, PAHs, PCDD/Fs and PCBs. HepG2 cells were used as a model for the human liver and BALB/c 3T3 cells to evaluate carcinogenic potential. Cells were treated with soil extractable organic matter (EOM) and the MTS assay, DNA release and morphological transformation were selected as endpoints for toxicity and carcinogenicity. Soil EOMs induced dose-dependent inhibition of cell growth at low doses and cytotoxicity only at doses of 500 and 1000 mg soil equivalents/ml. Potential issues for human health can be hypothesized after ingestion of soil samples from some sites. No statistically significant inductions of foci were recorded after exposure to EOMs, indicating that the levels of the soil-extracted organic pollutants were too low to induce carcinogenesis in our experimental conditions. An acute phytotoxicity test and studies on Caenorhabditis elegans were used as ecotoxicological assays for plants and small invertebrates. No significant alerts for ecotoxicity were found. In this proposed case study, HepG2 cells detected differences in the toxicity of soil EOMs, indicating that this cell line could be appropriate to assess the potential harm caused by the ingestion of contaminated soil. Additional information on the carcinogenic potential of mixtures was provided by the cell transformation assay, strengthening the combined approach. - Highlights: • A combined approach for evaluation of soil quality is

Impact of bioavailability on the correlation between in vitro cytotoxic and in vivo acute fish toxic concentrations of chemicals

International Nuclear Information System (INIS)

Guelden, Michael; Seibert, Hasso

2005-01-01

The lower sensitivity of in vitro cytotoxicity assays currently restricts their use as alternative to the fish acute toxicity assays for hazard assessment of chemicals in the aquatic environment. In vitro cytotoxic potencies mostly refer to nominal concentrations. The main objective of the present study was to investigate, whether a reduced availability of chemicals in vitro can account for the lower sensitivity of in vitro toxicity test systems. For this purpose, the bioavailable free fractions of the nominal cytotoxic concentrations (EC 50 ) of chemicals determined with a cytotoxicity test system using Balb/c 3T3 cells and the corresponding free cytotoxic concentrations (ECu 50 ) were calculated. The algorithm applied is based on a previously developed simple equilibrium distribution model for chemicals in cell cultures with serum-supplemented culture media. This model considers the distribution of chemicals between water, lipids and serum albumin. The algorithm requires the relative lipid volume of the test system, the octanol-water partition coefficient (K ow ) and the in vitro albumin-bound fraction of the chemicals. The latter was determined from EC 50 -measurements in the presence of different albumin concentrations with the Balb/c 3T3 test system. Organic chemicals covering a wide range of cytotoxic potency (EC 50 : 0.16-527000 μM) and lipophilicity (log K ow : -5.0-6.96) were selected, for which fish acute toxicity data (LC 50 -values) from at least one of the three fish species, medaka, rainbow trout and fathead minnow, respectively, were available. The availability of several chemicals was shown to be extensively reduced either by partitioning into lipids or by serum albumin binding, or due to both mechanisms. Reduction of bioavailability became more important with increasing cytotoxic potency. The sensitivity of the Balb/c 3T3 cytotoxicity assay and the correspondence between in vivo and in vitro toxic potencies were increased when the free cytotoxic

Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

Energy Technology Data Exchange (ETDEWEB)

Palumbo, Fabrizio [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Garcia-Lainez, Guillermo [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Limones-Herrero, Daniel [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Coloma, M. Dolores; Escobar, Javier [Instituto de Investigación Sanitaria (IIS) La Fe, Hospital Universitari i Politècnic La Fe, Avenida de Fernando Abril Martorell 106, 46026 Valencia (Spain); Jiménez, M. Consuelo [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); Miranda, Miguel A., E-mail: mmiranda@qim.upv.es [Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia (Spain); and others

2016-12-15

Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis. �

Enhanced photo(geno)toxicity of demethylated chlorpromazine metabolites

International Nuclear Information System (INIS)

Palumbo, Fabrizio; Garcia-Lainez, Guillermo; Limones-Herrero, Daniel; Coloma, M. Dolores; Escobar, Javier; Jiménez, M. Consuelo; Miranda, Miguel A.

2016-01-01

Chlorpromazine (CPZ) is an anti-psychotic drug widely used to treat disorders such as schizophrenia or manic-depression. Unfortunately, CPZ exhibits undesirable side effects such as phototoxic and photoallergic reactions in humans. In general, the influence of drug metabolism on this type of reactions has not been previously considered in photosafety testing. Thus, the present work aims to investigate the possible photo(geno)toxic potential of drug metabolites, using CPZ as an established reference compound. In this case, the metabolites selected for the study are demethylchlorpromazine (DMCPZ), didemethylchlorpromazine (DDMCPZ) and chlorpromazine sulfoxide (CPZSO). The demethylated CPZ metabolites DMCPZ and DDMCPZ maintain identical chromophore to the parent drug. In this work, it has been found that the nature of the aminoalkyl side chain modulates the hydrophobicity and the photochemical properties (for instance, the excited state lifetimes), but it does not change the photoreactivity pattern, which is characterized by reductive photodehalogenation, triggered by homolytic carbon-chlorine bond cleavage with formation of highly reactive aryl radical intermediates. Accordingly, these metabolites are phototoxic to cells, as revealed by the 3T3 NRU assay; their photo-irritation factors are even higher than that of CPZ. The same trend is observed in photogenotoxicity studies, both with isolated and with cellular DNA, where DMCPZ and DDMCPZ are more active than CPZ itself. In summary, side-chain demethylation of CPZ, as a consequence of Phase I biotransformation, does not result a photodetoxification. Instead, it leads to metabolites that exhibit in an even enhanced photo(geno)toxicity. - Highlights: • Demethylated CPZ metabolites are phototoxic to cells, as revealed by the NRU assay. • Single cell electrophoresis (Comet Assay) confirms the photodamage to cellular DNA. • DNA single strand breaks formation is observed on agarose gel electrophoresis. �

Toxic metal tolerance in native plant species grown in a vanadium mining area.

Science.gov (United States)

Aihemaiti, Aikelaimu; Jiang, Jianguo; Li, De'an; Li, Tianran; Zhang, Wenjie; Ding, Xutong

2017-12-01

Vanadium (V) has been extensively mined in China and caused soil pollution in mining area. It has toxic effects on plants, animals and humans, posing potential health risks to communities that farm and graze cattle adjacent to the mining area. To evaluate in situ phytoremediation potentials of native plants, V, chromium, copper and zinc concentrations in roots and shoots were measured and the bioaccumulation (BAF) and translocation (TF) efficiencies were calculated. The results showed that Setaria viridis accumulated greater than 1000 mg kg -1 V in its shoots and exhibited TF > 1 for V, Cr, Zn and BAF > 1 for Cu. The V accumulation amount in the roots of Kochia scoparia also surpassed 1000 mg kg -1 and showed TF > 1 for Zn. Chenopodium album had BAF > 1 for V and Zn and Daucus carota showed TF > 1 for Cu. Eleusine indica presented strong tolerance and high metal accumulations. S. viridis is practical for in situ phytoextractions of V, Cr and Zn and phytostabilisation of Cu in V mining area. Other species had low potential use as phytoremediation plant at multi-metal polluted sites, but showed relatively strong resistance to V, Cr, Cu and Zn toxicity, can be used to vegetate the contaminated soils and stabilise toxic metals in V mining area.

Application of Bioassays for the Ecotoxicity Assessment of Contaminated Soils

Science.gov (United States)

Fernández, María D.; Babín, Mar; Tarazona, José V.

The use of bioassays for soil characterization is receiving significant attention as a complementary tool to chemical analysis. Bioassays consist of direct toxicity assays of environmental samples that are transferred to the laboratory and analyzed for toxicity against selected organisms. Such soil samples contain the combination of the different pollutants present in situ and enable factors such as the bioavailability of contaminants or the interactions (synergic and antagonic) between them to be simultaneously studied.

Comparison of solid-phase and eluate assays to gauge the ecotoxicological risk of organic wastes on soil organisms

International Nuclear Information System (INIS)

Domene, Xavier; Alcaniz, Josep M.; Andres, Pilar

2008-01-01

Development of methodologies to assess the safety of reusing polluted organic wastes in soil is a priority in Europe. In this study, and coupled with chemical analysis, seven organic wastes were subjected to different aquatic and soil bioassays. Tests were carried out with solid-phase waste and three different waste eluates (water, methanol, and dichloromethane). Solid-phase assays were indicated as the most suitable for waste testing not only in terms of relevance for real situations, but also because toxicity in eluates was generally not representative of the chronic effects in solid-phase. No general correlations were found between toxicity and waste pollutant burden, neither in solid-phase nor in eluate assays, showing the inability of chemical methods to predict the ecotoxicological risks of wastes. On the contrary, several physicochemical parameters reflecting the degree of low organic matter stability in wastes were the main contributors to the acute toxicity seen in collembolans and daphnids. - Comparison of solid-phase and eluate bioassays for organic waste testing

Acylcarnitine Profiles in Acetaminophen Toxicity in the Mouse: Comparison to Toxicity, Metabolism and Hepatocyte Regeneration

Directory of Open Access Journals (Sweden)

Jack Hinson

2013-08-01

Full Text Available High doses of acetaminophen (APAP result in hepatotoxicity that involves metabolic activation of the parent compound, covalent binding of the reactive intermediate N-acetyl-p-benzoquinone imine (NAPQI to liver proteins, and depletion of hepatic glutathione. Impaired fatty acid β-oxidation has been implicated in previous studies of APAP-induced hepatotoxicity. To better understand relationships between toxicity and fatty acid β-oxidation in the liver in APAP toxicity, metabolomic assays for long chain acylcarnitines were examined in relationship to established markers of liver toxicity, oxidative metabolism, and liver regeneration in a time course study in mice. Male B6C3F1 mice were treated with APAP (200 mg/kg IP or saline and sacrificed at 1, 2, 4, 8, 24 or 48 h after APAP. At 1 h, hepatic glutathione was depleted and APAP protein adducts were markedly increased. Alanine aminotransferase (ALT levels were elevated at 4 and 8 h, while proliferating cell nuclear antigen (PCNA expression, indicative of hepatocyte regeneration, was apparent at 24 h and 48 h. Elevations of palmitoyl, oleoyl and myristoyl carnitine were apparent by 2–4 h, concurrent with the onset of Oil Red O staining in liver sections. By 8 h, acylcarnitine levels were below baseline levels and remained low at 24 and 48 h. A partial least squares (PLS model suggested a direct association of acylcarnitine accumulation in serum to APAP protein adduct and hepatic glutathione levels in mice. Overall, the kinetics of serum acylcarnitines in APAP toxicity in mice followed a biphasic pattern involving early elevation after the metabolism phases of toxicity and later depletion of acylcarnitines.

Potential of antioxidant and toxicity of some medical plants used by sub-ethnic communities of Bahau in East Kalimantan

Science.gov (United States)

Rohim, P.; Arung, E. T.; Kusuma, I. W.

2018-04-01

The purpose of this research is to assay the potential antioxidant and toxicity of several plants from Bahau, a sub-ethnic in East Kalimantan in regard to their utilization as traditional medicines. This research includes phytochemical analysis, DPPH radical and superoxide radical scavenging activity as well as toxicity assay using Artemiasalina shrimp larvae. The results of the extraction showed the highest yield was 2,91% obtained from avung tanaq (Ficus uncinata), while the lowest is 1.14% obtained from tevoqsalah (Saccharum sp.) species. The result of phytochemicals showed that all plants contain alkaloid and carbohydrate. While carotenoids, saponins, triterpenoids and steroids were absence in all plant extracts. The DPPH radical scavenging activity test showed that the lowest IC50 value of kayog kue (Dictamnus albus) by 23.96 μg/mL. The superoxide radical scavenging activity assay showed IC50 values of all extract samples were >100 μg/mL. The toxicity assay showed that LC50 values of all samples of extract tested were >1000 μg/mL. The present research suggested good potential activity of some plants from Bahau ethnic and further research oriented to wide uses of the plants as herbal products is needed.

40 CFR 798.5395 - In vivo mammalian bone marrow cytogenetics tests: Micronucleus assay.

Science.gov (United States)

2010-07-01

... Genetic Toxicity § 798.5395 In vivo mammalian bone marrow cytogenetics tests: Micronucleus assay. (a... and documented with data, only this one time point need be sampled. (ii) If a repeated treatment... slides, spread as a smear and stained. (2) Analysis. Slides shall be coded before microscopic analysis...

Genotoxic and Cytotoxic Safety Evaluation of Papain (Carica papaya L. Using In Vitro Assays

Directory of Open Access Journals (Sweden)

Claudia R. da Silva

2010-01-01

This work evaluated the toxic and mutagenic potential of papain and its potential antioxidant activity against induced-H2O2 oxidative stress in Escherichia coli strains. Cytotoxicity assay, Growth inhibition test, WP2-Mutoxitest and Plasmid-DNA treatment, and agarose gel electrophoresis were used to investigate if papain would present any toxic or mutagenic potential as well as if papain would display antioxidant properties. Papain exhibited negative results for all tests. This agent presented an activity protecting cells against H2O2-induced mutagenesis.

Resveratrol Sensitizes Selectively Thyroid Cancer Cell to 131-Iodine Toxicity

Directory of Open Access Journals (Sweden)

Seyed Jalal Hosseinimehr

2014-01-01

Full Text Available Background. In this study, the radiosensitizing effect of resveratrol as a natural product was investigated on cell toxicity induced by 131I in thyroid cancer cell. Methods. Human thyroid cancer cell and human nonmalignant fibroblast cell (HFFF2 were treated with 131I and/or resveratrol at different concentrations for 48 h. The cell proliferation was measured by determination of the percent of the survival cells using 3-(4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. Results. Findings of this study show that resveratrol enhanced the cell death induced by 131I on thyroid cancer cell. Also, resveratrol exhibited a protective effect on normal cells against 131I toxicity. Conclusion. This result indicates a promising effect of resveratrol on improvement of cellular toxicity during iodine therapy.

Personal care product preservatives: risk assessment and mixture toxicities with an industrial wastewater.

Science.gov (United States)

Carbajo, Jose B; Perdigón-Melón, Jose A; Petre, Alice L; Rosal, Roberto; Letón, Pedro; García-Calvo, Eloy

2015-04-01

The aquatic toxicity of eight preservatives frequently used in personal care products (PCPs) (iodopropynyl butylcarbamate, bronopol, diazolidinyl urea, benzalkonium chloride, zinc pyrithione, propylparaben, triclosan and a mixture of methylchloroisothiazolinone and methylisothiazolinone) was assessed by means of two different approaches: a battery of bioassays composed of single species tests of bacteria (Vibrio fischeri and Pseudomonas putida) and protozoa (Tetrahymena thermophila), and a whole biological community resazurin-based assay using activated sludge. The tested preservatives showed considerable toxicity in the studied bioassays, but with a marked difference in potency. In fact, all biocides except propylparaben and diazolidinyl urea had EC50 values lower than 1 mg L(-1) in at least one assay. Risk quotients for zinc pyrithione, benzalkonium chloride, iodopropynyl butylcarbamate and triclosan as well as the mixture of the studied preservatives exceeded 1, indicating a potential risk for the process performance and efficiency of municipal sewage treatment plants (STPs). These four single biocides explained more than 95% of the preservative mixture risk in all bioassays. Each individual preservative was also tested in combination with an industrial wastewater (IWW) from a cosmetics manufacturing facility. The toxicity assessment was performed on binary mixtures (preservative + IWW) and carried out using the median-effect principle, which is a special case of the concept of Concentration Addition (CA). Almost 70% of all experiments resulted in EC50 values within a factor of 2 of the values predicted by the median-effect principle (CI values between 0.5 and 2). The rest of the mixtures whose toxicity was mispredicted by CA were assessed with the alternative concept of Independent Action (IA), which showed higher predictive power for the biological community assay. Therefore, the concept used to accurately predict the toxicity of mixtures of a preservative

A non-isotopic assay uses bromouridine and RNA synthesis to detect DNA damage responses.

Science.gov (United States)

Hasegawa, Mayu; Iwai, Shigenori; Kuraoka, Isao

2010-06-17

Individuals with inherited xeroderma pigmentosum (XP) disorder and Cockayne syndrome (CS) are deficient in nucleotide excision repair and experience hypersensitivity to sunlight. Although there are several diagnostic assays for these disorders, the recovery of RNA synthesis (RRS) assay that can discriminate between XP cells and CS cells is very laborious. Here, we report on a novel non-radioisotope RRS assay that uses bromouridine (a uridine analog) as an alternative to (3)H-uridine. This assay can easily detect RNA polymerase I transcription in nucleoli and RNA polymerase II transcription in nuclei. The non-RI RSS assay also can rapidly detect normal RRS activity in HeLa cells. Thus, this assay is useful as a novel and easy technique for CS diagnosis. Because RRS is thought to be related to transcription-coupled DNA repair, which is triggered by the blockage of transcriptional machinery by DNA lesions, this assay may be of use for analysis of DNA repair, transcription, and/or genetic toxicity. Copyright 2010 Elsevier B.V. All rights reserved.

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

NARCIS (Netherlands)

Bosgra, S.; Westerhout, J.

2015-01-01

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

In situ PCR detection of phytoplasma DNA in embryos from coconut palms with lethal yellowing disease.

Science.gov (United States)

Cordova, Ivan; Jones, Phil; Harrison, Nigel A; Oropeza, Carlos

2003-03-01

SUMMARY DNA of the lethal yellowing (LY) phytoplasma was detected in 13 of 72 embryos from fruits of four diseased Atlantic tall coconut palms by polymerase chain reaction (PCR) assays employing phytoplasma universal rRNA primer pair P1/P7, nested LY group-specific rRNA primer pair 503f/LY16Sr or LY phytoplasma-specific nonribosomal primer pair LYF1/R1. Phytoplasma distribution in sectioned tissues from six PCR positive embryos was determined by in situ PCR and digoxigenin-11-deoxy-UTP (Dig) labelling of amplification products. Dig-labeled DNA products detected by colourimetric assay were clearly evident on sections from the same three embryos investigated in detail by in situ PCRs employing primer pairs P1/P7 or LYF1/R1. Deposition of blue-green stain on sections as a result of each assay was restricted to areas of the embryos corresponding to the plumule and cells ensheathing it. By comparison, similarly treated embryo sections derived from fruits of a symptomless Atlantic tall coconut palm were consistently devoid of any stain. Presence of phytoplasma DNA in embryo tissues suggests the possible potential for seed transmission which remains to be demonstrated.

Critical issues with the in vivo comet assay: A report of the comet assay working group in the 6th International Workshop on Genotoxicity Testing (IWGT).

Science.gov (United States)

Speit, Günter; Kojima, Hajime; Burlinson, Brian; Collins, Andrew R; Kasper, Peter; Plappert-Helbig, Ulla; Uno, Yoshifumi; Vasquez, Marie; Beevers, Carol; De Boeck, Marlies; Escobar, Patricia A; Kitamoto, Sachiko; Pant, Kamala; Pfuhler, Stefan; Tanaka, Jin; Levy, Dan D

2015-05-01

As a part of the 6th IWGT, an expert working group on the comet assay evaluated critical topics related to the use of the in vivo comet assay in regulatory genotoxicity testing. The areas covered were: identification of the domain of applicability and regulatory acceptance, identification of critical parameters of the protocol and attempts to standardize the assay, experience with combination and integration with other in vivo studies, demonstration of laboratory proficiency, sensitivity and power of the protocol used, use of different tissues, freezing of samples, and choice of appropriate measures of cytotoxicity. The standard protocol detects various types of DNA lesions but it does not detect all types of DNA damage. Modifications of the standard protocol may be used to detect additional types of specific DNA damage (e.g., cross-links, bulky adducts, oxidized bases). In addition, the working group identified critical parameters that should be carefully controlled and described in detail in every published study protocol. In vivo comet assay results are more reliable if they were obtained in laboratories that have demonstrated proficiency. This includes demonstration of adequate response to vehicle controls and an adequate response to a positive control for each tissue being examined. There was a general agreement that freezing of samples is an option but more data are needed in order to establish generally accepted protocols. With regard to tissue toxicity, the working group concluded that cytotoxicity could be a confounder of comet results. It is recommended to look at multiple parameters such as histopathological observations, organ-specific clinical chemistry as well as indicators of tissue inflammation to decide whether compound-specific toxicity might influence the result. The expert working group concluded that the alkaline in vivo comet assay is a mature test for the evaluation of genotoxicity and can be recommended to regulatory agencies for use

Amendment in phosphorus levels moderate the chromium toxicity in Raphanus sativus L. as assayed by antioxidant enzymes activities.

Science.gov (United States)

Sayantan, D; Shardendu

2013-09-01

Chromium (Z=24), a d-block element, is a potent carcinogen, whereas phosphorus is an essential and limiting nutrient for the plant growth and development. This study undertakes the role of phosphorus in moderating the chromium toxicity in Raphanus sativus L., as both of them compete with each other during the uptake process. Two-factor complete randomized experiment (5 chromium × 5 phosphorus concentrations) was conducted for twenty eight days in green house. The individuals of R. sativus were grown in pots supplied with all essential nutrients. The toxic effects of chromium and the moderation of toxicity due to phosphorus amendment were determined as accumulation of chromium, nitrogen, phosphorus in root tissues and their effects were also examined in the changes in biomass, chlorophyll and antioxidant enzyme levels. Cr and N accumulation were almost doubled at the highest concentration of Cr supply, without any P amendment, whereas at the highest P concentration (125 mM), the accumulation was reduced to almost half. A significant reduction in toxic effects of Cr was determined as there was three-fold increase in total chlorophyll and biomass at the highest P amendment. Antioxidant enzymes like superoxide dismutase, catalase, peroxidase and lipid peroxidation were analyzed at various levels of Cr each amended with five levels of P. It was observed that at highest level of P amendment, the reduction percentage in toxicity was 33, 44, 39 and 44, correspondingly. Conclusively, the phosphorus amendment moderates the toxicity caused by the supplied chromium in R. sativus. This finding can be utilized to develop a novel technology for the amelioration of chromium stressed fields. Copyright © 2013 Elsevier Inc. All rights reserved.

Biomarker-Based Analysis for Contaminants in Sediments/Soil: Review of Cell-Based Assays and cDNA Arrays

National Research Council Canada - National Science Library

Inouye, Laura

2000-01-01

This technical note reviews the existing technology for cell-based biomarker assays and cDNA arrays and explores their potential as rapid, sensitive, and low-cost tools for sediment/soil toxicity screening...

Acute toxicity of anionic and non-ionic surfactants to aquatic organisms.

Science.gov (United States)

Lechuga, M; Fernández-Serrano, M; Jurado, E; Núñez-Olea, J; Ríos, F

2016-03-01

The environmental risk of surfactants requires toxicity measurements. As different test organisms have different sensitivity to the toxics, it is necessary to establish the most appropriate organism to classify the surfactant as very toxic, toxic, harmful or safe, in order to establish the maximum permissible concentrations in aquatic ecosystems. We have determined the toxicity values of various anionic surfactants ether carboxylic derivatives using four test organisms: the freshwater crustacean Daphnia magna, the luminescent bacterium Vibrio fischeri, the microalgae Selenastrum capricornutum (freshwater algae) and Phaeodactylum tricornutum (seawater algae). In addition, in order to compare and classify the different families of surfactants, we have included a compilation of toxicity data of surfactants collected from literature. The results indicated that V. fischeri was more sensitive to the toxic effects of the surfactants than was D. magna or the microalgae, which was the least sensitive. This result shows that the most suitable toxicity assay for surfactants may be the one using V. fischeri. The toxicity data revealed considerable variation in toxicity responses with the structure of the surfactants regardless of the species tested. The toxicity data have been related to the structure of the surfactants, giving a mathematical relationship that helps to predict the toxic potential of a surfactant from its structure. Model-predicted toxicity agreed well with toxicity values reported in the literature for several surfactants previously studied. Predictive models of toxicity is a handy tool for providing a risk assessment that can be useful to establish the toxicity range for each surfactant and the different test organisms in order to select efficient surfactants with a lower impact on the aquatic environment. Copyright © 2015 Elsevier Inc. All rights reserved.

Comparison of Microtox and Xenoassay Light as a Near Real Time River Monitoring Assay for Heavy Metals

Directory of Open Access Journals (Sweden)

M. I. E. Halmi

2014-01-01

Full Text Available Luminescence-based assays for toxicants such as Microtox, ToxAlert, and Biotox have been used extensively worldwide. However, the use of these assays in near real time conditions is limited due to nonoptimal assay temperature for the tropical climate. An isolate that exhibits a high luminescence activity in a broad range of temperatures was successfully isolated from the mackerel, Rastrelliger kanagurta. This isolate was tentatively identified as Photobacterium sp. strain MIE, based on partial 16S rDNA molecular phylogeny. Optimum conditions that support high bioluminescence activity occurred between 24 and 30°C, with pH 5.5 to 7.5, 10 to 20 g/L of sodium chloride, 30 to 50 g/L of tryptone, and 4 g/L of glycerol as the carbon source. Assessment of near real time capability of this bacterial system, Xenoassay light to monitor heavy metals from a contaminated river running through the Juru River Basin shows near real time capability with assaying time of less than 30 minutes per samples. Samples returned to the lab were tested with a standard Microtox assay using Vibrio fishceri. Similar results were obtained to Xenoassay light that show temporal variation of copper concentration. Thus, this strain is suitable for near real time river monitoring of toxicants especially in the tropics.

Multiple-endpoints gene alteration-based (MEGA) assay: A toxicogenomics approach for water quality assessment of wastewater effluents.

Science.gov (United States)

Fukushima, Toshikazu; Hara-Yamamura, Hiroe; Nakashima, Koji; Tan, Lea Chua; Okabe, Satoshi

2017-12-01

Wastewater effluents contain a significant number of toxic contaminants, which, even at low concentrations, display a wide variety of toxic actions. In this study, we developed a multiple-endpoints gene alteration-based (MEGA) assay, a real-time PCR-based transcriptomic analysis, to assess the water quality of wastewater effluents for human health risk assessment and management. Twenty-one genes from the human hepatoblastoma cell line (HepG2), covering the basic health-relevant stress responses such as response to xenobiotics, genotoxicity, and cytotoxicity, were selected and incorporated into the MEGA assay. The genes related to the p53-mediated DNA damage response and cytochrome P450 were selected as markers for genotoxicity and response to xenobiotics, respectively. Additionally, the genes that were dose-dependently regulated by exposure to the wastewater effluents were chosen as markers for cytotoxicity. The alterations in the expression of an individual gene, induced by exposure to the wastewater effluents, were evaluated by real-time PCR and the results were validated by genotoxicity (e.g., comet assay) and cell-based cytotoxicity tests. In summary, the MEGA assay is a real-time PCR-based assay that targets cellular responses to contaminants present in wastewater effluents at the transcriptional level; it is rapid, cost-effective, and high-throughput and can thus complement any chemical analysis for water quality assessment and management. Copyright © 2017 Elsevier Ltd. All rights reserved.

Contribution of different constituents to the toxicity of the essential oil ...

African Journals Online (AJOL)

The lethal toxicity of the major constituent of the essential oils of Vernonia amygdalina and Xylopia aetiopica, and of selected blends of these against Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) was compared with those of the full blends of the essential oils. The compounds were assayed in amounts and ...

Automated evaluation of pharmaceutically active ionic liquids’ (eco)toxicity through the inhibition of human carboxylesterase and Vibrio fischeri

International Nuclear Information System (INIS)

Costa, Susana P.F.; Justina, Vanessa D.; Bica, Katharina; Vasiloiu, Maria; Pinto, Paula C.A.G.; Saraiva, M. Lúcia M.F.S.

2014-01-01

Highlights: • IL-APIs toxicity on humans and aquatic environment was evaluated by inhibition assays. • The inhibition assays were implemented through automated screening bioassays. • Automation of bioassays enabled a rigorous control of the reaction conditions. • EC 50 obtained provide vital information on IL-APIs safety and potential use as drugs. -- Abstract: The toxicity of 16 pharmaceutical active ionic liquids (IL-APIs) was evaluated by automated approaches based on sequential injection analysis (SIA). The implemented bioassays were centered on the inhibition of human carboxylesterase 2 and Vibrio fischeri, in the presence of the tested compounds. The inhibitory effects were quantified by calculating the inhibitor concentration required to cause 50% of inhibition (EC 50 ). The EC 50 values demonstrated that the cetylpyridinium group was one of the most toxic cations and that the imidazolium group was the less toxic. The obtained results provide important information about the safety of the studied IL-APIs and their possible use as pharmaceutical drugs. The developed automated SIA methodologies are robust screening bioassays, and can be used as a generic tools to identify the (eco)toxicity of the structural elements of ILs, contributing to a sustainable development of drugs

Radioimmunoassay, acetylating radio-enzymatic assay, and microbioassay of gentamicin: a comparative study

International Nuclear Information System (INIS)

Stevens, P.; Young, L.S.; Hewitt, W.L.

1975-01-01

Gentamicin is an aminoglycoside antibiotic widely used to treat gram-negative bacillary infections. Because it has a low therapeutic index, monitoring of serum levels may help to insure adequacy of dosage and avoid toxicity. Microbiological assays are relatively slow and can be complicated by the presence of other antimicrobials. Radioimmunoassay (RIA) and acetylating radio-enzymatic assay (ARA) are new methods for gentamicin assay which offer the following advantages: rapidity (less than 3 hours); no interference by other antibiotics; RIA is extremely sensitive and ARA is versatile (being useful in the measurement of other aminoglycosides). Correlation coefficients determined by linear regression analysis of assays on 36 patient samples performed in duplicate on 2 different days demonstrated no significant difference in measurement of gentamicin by each of the methods. Factors such as numbers of specimens, cost, and time involved will affect the decision of the method to be applied in individual laboratories. (U.S.)

Acute and subacute toxicity of 18F-FDG

International Nuclear Information System (INIS)

Dantas, Danielle Maia

2013-01-01

Before starting clinical trials of a new drug, it is necessary to perform a battery of safety tests for assessing human risk. Radiopharmaceuticals like any new drug must be tested taking into account its specificity, duration of treatment and especially the toxicity of both parties, the unlabeled molecule and its radionuclide, apart from impurities emanating from radiolysis. Regulatory agencies like the Food and Drug Administration - USA (FDA) and the European Medicine Agency (EMEA), establish guidelines for the regulation of production and research of radiopharmaceuticals. In Brazil the production of radiopharmaceuticals was not regulated until the end of 2009, when were established by the National Agency for Sanitary Surveillance (ANVISA) resolutions No. 63, which refers to the Good Manufacturing Practices of Radiopharmaceuticals and No. 64 which seeks the registration of record radiopharmaceuticals. To obtain registration of radiopharmaceuticals are necessary to prove the quality, safety, efficacy and specificity of the drug . For the safety of radiopharmaceuticals must be presented studies of acute toxicity, subacute and chronic toxicity as well as reproductive, mutagenic and carcinogenic. Nowadays IPEN-CNEN/SP produces one of the most important radiopharmaceutical of nuclear medicine, the 18 F-FDG, which is used in many clinical applications, particularly in the diagnosis and staging of tumors. The objective of this study was to evaluate the systemic toxicity (acute/ subacute) radiopharmaceutical 18 F-FDG in an in vivo test system, as recommended by the RDC No. 64, which will serve as a model for protocols toxicity of radiopharmaceuticals produced at IPEN. The following tests were performed: tests of acute and subacute toxicity, biodistribution studies of 18 F-FDG, comet assay and reproductive toxicity. In acute toxicity, healthy rats were injected . (author)

Abrin Toxicity and Bioavailability after Temperature and pH Treatment

Directory of Open Access Journals (Sweden)

Christina C. Tam

2017-10-01

Full Text Available Abrin, one of most potent toxins known to man, is derived from the rosary pea (jequirity pea, Abrus precatorius and is a potential bioterror weapon. The temperature and pH stability of abrin was evaluated with an in vitro cell free translation (CFT assay, a Vero cell culture cytotoxicity assay, and an in vivo mouse bioassay. pH treatment of abrin had no detrimental effect on its stability and toxicity as seen either in vitro or in vivo. Abrin exposure to increasing temperatures did not completely abrogate protein translation. In both the cell culture cytotoxicity model and the mouse bioassay, abrin’s toxic effects were completely abrogated if the toxin was exposed to temperatures of 74 °C or higher. In the cell culture model, 63 °C-treated abrin had a 30% reduction in cytotoxicity which was validated in the in vivo mouse bioassay with all mice dying but with a slight time-to-death delay as compared to the non-treated abrin control. Since temperature inactivation did not affect abrin’s ability to inhibit protein synthesis (A-chain, we hypothesize that high temperature treatment affected abrin’s ability to bind to cellular receptors (affecting B-chain. Our results confirm the absolute need to validate in vitro cytotoxicity assays with in vivo mouse bioassays.

Sperm shape abnormalities induced by energy-related hydrocarbons and industrial chemicals. Progress report, January 1-June 30, 1979

International Nuclear Information System (INIS)

Wyrobek, A.J.

1979-01-01

Using existing and new biological screening and testing systems, the presence of carcinogenic, mutagenic, teratogenic and physiologic or metabolically toxic agents associated with coal and oil shale extraction, conversion or utilization was identified. The purpose of the study is to further develop and apply the detection of morphologically abnormal mammalian sperm as a rapid, simple, quantitative assay of the pathologic response of the male gonad to toxic agents associated with the recovery, process stream, and emission of nonnuclear sources of energy, with primary attention to substances from in situ coal gasification and in situ oil-shale extraction. Changes in mouse sperm head dimensions following low dose x-ray exposure have been compiled and analyzed

Toxicity of nano- and micro-sized silver particles in human hepatocyte cell line L02

International Nuclear Information System (INIS)

Liu Pengpeng; Guan Rongfa; Jiang Jiaxin; Liu Mingqi; Huang Guangrong; Chen Xiaoting; Ye Xingqian

2011-01-01

Silver nanoparticles (Ag NPs) previously classified as antimicrobial agents have been widely used in consumers and industrial products, especially food storage material. Ag NPs used as antimicrobial agents may be found in liver. Thus, examination of the ability of Ag NPs to penetrate the liver is warranted. The aim of the study was to determine the optimal viability assay for using with Ag NPs in order to assess their toxicity to liver cells. For toxicity evaluations, cellular morphology, mitochondrial function (3-(4, 5-dimethylazol-2-yl)-2, 5-diphenyl-tetrazolium bromide, MTT assay), membrane leakage of lactate dehydrogenase (lactate dehydrogenase, LDH release assay), Oxidative stress markers (malonaldehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD)), DNA damage (single cell gel eletrophoresis, SCGE assay), and protein damage were assessed under control and exposed conditions (24 h of exposure). The results showed that mitochondrial function decreased significantly in cells exposed to Ag NPs at 25 μg·mL -1 . LDH leakage significantly increased in cells exposed to Ag NPs (≥ 25 μg mL -1 ) while micro-sized silver particles tested displayed LDH leakage only at higher doses (100 μg·mL -1 ). The microscopic studies demonstrated that nanoparticle-exposed cells at higher doses became abnormal in size, displaying cellular shrinkage, and an acquisition of an irregular shape. Due to toxicity of silver, further study conducted with reference to its oxidative stress. The results exhibited significant depletion of GSH level, increase in SOD levels and lead to lipid peroxidation, which suggested that cytotoxicity of Ag NPs in liver cells might be mediated through oxidative stress. The results demonstrates that Ag NPs lead to cellular morphological modifications, LDH leakage, mitochondrial dysfunction, and cause increased generation of ROS, depletion of GSH, lipid peroxidation, oxidative DNA damage and protein damage. Though the exact mechanism behind Ag NPs

Toxicity of nano- and micro-sized silver particles in human hepatocyte cell line L02

Science.gov (United States)

Liu, Pengpeng; Guan, Rongfa; Ye, Xingqian; Jiang, Jiaxin; Liu, Mingqi; Huang, Guangrong; Chen, Xiaoting

2011-07-01

Silver nanoparticles (Ag NPs) previously classified as antimicrobial agents have been widely used in consumers and industrial products, especially food storage material. Ag NPs used as antimicrobial agents may be found in liver. Thus, examination of the ability of Ag NPs to penetrate the liver is warranted. The aim of the study was to determine the optimal viability assay for using with Ag NPs in order to assess their toxicity to liver cells. For toxicity evaluations, cellular morphology, mitochondrial function (3-(4, 5-dimethylazol-2-yl)-2, 5-diphenyl-tetrazolium bromide, MTT assay), membrane leakage of lactate dehydrogenase (lactate dehydrogenase, LDH release assay), Oxidative stress markers (malonaldehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD)), DNA damage (single cell gel eletrophoresis, SCGE assay), and protein damage were assessed under control and exposed conditions (24 h of exposure). The results showed that mitochondrial function decreased significantly in cells exposed to Ag NPs at 25 μg·mL-1. LDH leakage significantly increased in cells exposed to Ag NPs (>= 25 μg mL-1) while micro-sized silver particles tested displayed LDH leakage only at higher doses (100 μg·mL-1). The microscopic studies demonstrated that nanoparticle-exposed cells at higher doses became abnormal in size, displaying cellular shrinkage, and an acquisition of an irregular shape. Due to toxicity of silver, further study conducted with reference to its oxidative stress. The results exhibited significant depletion of GSH level, increase in SOD levels and lead to lipid peroxidation, which suggested that cytotoxicity of Ag NPs in liver cells might be mediated through oxidative stress. The results demonstrates that Ag NPs lead to cellular morphological modifications, LDH leakage, mitochondrial dysfunction, and cause increased generation of ROS, depletion of GSH, lipid peroxidation, oxidative DNA damage and protein damage. Though the exact mechanism behind Ag NPs

Toxicity of nano- and micro-sized silver particles in human hepatocyte cell line L02

Energy Technology Data Exchange (ETDEWEB)

Liu Pengpeng; Guan Rongfa; Jiang Jiaxin; Liu Mingqi; Huang Guangrong; Chen Xiaoting [Zhejiang Provincial Key Laboratory of Biometrology and Inspection and Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018 (China); Ye Xingqian, E-mail: rfguan@163.com [Department of Food Science and Nutrition, School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou 310029 (China)

2011-07-06

Silver nanoparticles (Ag NPs) previously classified as antimicrobial agents have been widely used in consumers and industrial products, especially food storage material. Ag NPs used as antimicrobial agents may be found in liver. Thus, examination of the ability of Ag NPs to penetrate the liver is warranted. The aim of the study was to determine the optimal viability assay for using with Ag NPs in order to assess their toxicity to liver cells. For toxicity evaluations, cellular morphology, mitochondrial function (3-(4, 5-dimethylazol-2-yl)-2, 5-diphenyl-tetrazolium bromide, MTT assay), membrane leakage of lactate dehydrogenase (lactate dehydrogenase, LDH release assay), Oxidative stress markers (malonaldehyde (MDA), glutathione (GSH) and superoxide dismutase (SOD)), DNA damage (single cell gel eletrophoresis, SCGE assay), and protein damage were assessed under control and exposed conditions (24 h of exposure). The results showed that mitochondrial function decreased significantly in cells exposed to Ag NPs at 25 {mu}g{center_dot}mL{sup -1}. LDH leakage significantly increased in cells exposed to Ag NPs ({>=} 25 {mu}g mL{sup -1}) while micro-sized silver particles tested displayed LDH leakage only at higher doses (100 {mu}g{center_dot}mL{sup -1}). The microscopic studies demonstrated that nanoparticle-exposed cells at higher doses became abnormal in size, displaying cellular shrinkage, and an acquisition of an irregular shape. Due to toxicity of silver, further study conducted with reference to its oxidative stress. The results exhibited significant depletion of GSH level, increase in SOD levels and lead to lipid peroxidation, which suggested that cytotoxicity of Ag NPs in liver cells might be mediated through oxidative stress. The results demonstrates that Ag NPs lead to cellular morphological modifications, LDH leakage, mitochondrial dysfunction, and cause increased generation of ROS, depletion of GSH, lipid peroxidation, oxidative DNA damage and protein damage

In Situ Enzymatically Generated Photoswitchable Oxidase Mimetics and Their Application for Colorimetric Detection of Glucose Oxidase.

Science.gov (United States)

Cao, Gen-Xia; Wu, Xiu-Ming; Dong, Yu-Ming; Li, Zai-Jun; Wang, Guang-Li

2016-07-09

In this study, a simple and amplified colorimetric assay is developed for the detection of the enzymatic activity of glucose oxidase (GOx) based on in situ formation of a photoswitchable oxidase mimetic of PO₄(3-)-capped CdS quantum dots (QDs). GOx catalyzes the oxidation of 1-thio-β-d-glucose to give 1-thio-β-d-gluconic acid which spontaneously hydrolyzes to β-d-gluconic acid and H₂S; the generated H₂S instantly reacts with Cd(2+) in the presence of Na₃PO₄ to give PO₄(3-)-stabilized CdS QDs in situ. Under visible-light (λ ≥ 400 nm) stimulation, the PO₄(3-)-capped CdS QDs are a new style of oxidase mimic derived by producing some active species, such as h⁺, (•)OH, O₂(•-) and a little H₂O₂, which can oxidize the typical substrate (3,3,5,5-tetramethylbenzydine (TMB)) with a color change. Based on the GOx-triggered growth of the oxidase mimetics of PO₄(3-)-capped CdS QDs in situ, we developed a simple and amplified colorimetric assay to probe the enzymatic activity of GOx. The proposed method allowed the detection of the enzymatic activity of GOx over the range from 25 μg/L to 50 mg/L with a low detection limit of 6.6 μg/L. We believe the PO₄(3-)-capped CdS QDs generated in situ with photo-stimulated enzyme-mimicking activity may find wide potential applications in biosensors.

Toxicity assessment using different bioassays and microbial biosensors.

Science.gov (United States)

Hassan, Sedky H A; Van Ginkel, Steven W; Hussein, Mohamed A M; Abskharon, Romany; Oh, Sang-Eun

2016-01-01

Toxicity assessment of water streams, wastewater, and contaminated sediments, is a very important part of environmental pollution monitoring. Evaluation of biological effects using a rapid, sensitive and cost effective method can indicate specific information on ecotoxicity assessment. Recently, different biological assays for toxicity assessment based on higher and lower organisms such as fish, invertebrates, plants and algal cells, and microbial bioassays have been used. This review focuses on microbial biosensors as an analytical device for environmental, food, and biomedical applications. Different techniques which are commonly used in microbial biosensing include amperometry, potentiometry, conductometry, voltammetry, microbial fuel cells, fluorescence, bioluminescence, and colorimetry. Examples of the use of different microbial biosensors in assessing a variety of environments are summarized. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel approach for rapidly and cost-effectively assessing toxicity of toxic metals in acidic water using an acidophilic iron-oxidizing biosensor.

Science.gov (United States)

Yang, Shih-Hung; Cheng, Kuo-Chih; Liao, Vivian Hsiu-Chuan

2017-11-01

Contamination by heavy metals and metalloids is a serious environmental and health concern. Acidic wastewaters are often associated with toxic metals which may enter and spread into agricultural soils. Several biological assays have been developed to detect toxic metals; however, most of them can only detect toxic metals in a neutral pH, not in an acidic environment. In this study, an acidophilic iron-oxidizing bacterium (IOB) Strain Y10 was isolated, characterized, and used to detect toxic metals toxicity in acidic water at pH 2.5. The colorimetric acidophilic IOB biosensor was based on the inhibition of the iron oxidizing ability of Strain Y10, an acidophilic iron-oxidizing bacterium, by metals toxicity. Our results showed that Strain Y10 is acidophilic iron-oxidizing bacterium. Thiobacillus caldus medium (TCM) (pH 2.5) supplied with both S 4 O 6 2- and glucose was the optimum growth medium for Strain Y10. The optimum temperature and pH for the growth of Strain Y10 was 45 °C and pH 2.5, respectively. Our study demonstrates that the color-based acidophilic IOB biosensor can be semi-quantitatively observed by eye or quantitatively measured by spectrometer to detect toxicity from multiple toxic metals at pH 2.5 within 45 min. Our study shows that monitoring toxic metals in acidic water is possible by using the acidophilic IOB biosensor. Our study thus provides a novel approach for rapid and cost-effective detection of toxic metals in acidic conditions that can otherwise compromise current methods of chemical analysis. This method also allows for increased efficiency when screening large numbers of environmental samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

A fluorescence-based hydrolytic enzyme activity assay for quantifying toxic effects of Roundup® to Daphnia magna

DEFF Research Database (Denmark)

Ørsted, Michael; Roslev, Peter

2015-01-01

Daphnia magna is a widely used model organism for aquatic toxicity testing. In the present study, we investigated the hydrolytic enzyme activity of D. magna after exposure to toxicant stress. In vivo enzyme activity was quantified using 15 fluorogenic enzyme probes based on 4-methylumbelliferyl...... or 7-amino-4-methylcoumarin. Probing D. magna enzyme activity was evaluated using short-term exposure (24-48 h) to the reference chemical K2Cr2O7, or the herbicide formulation Roundup®. Toxicant induced changes in hydrolytic enzyme activity were compared to changes in mobility (ISO 6341). The results...... showed that hydrolytic enzyme activity was quantifiable as a combination of whole body fluorescence of D. magna, and fluorescence of the surrounding water. Exposure of D. magna to lethal and sublethal concentrations of Roundup® resulted in loss of whole body enzyme activity, and release of cell...

Three Strains of Pseudomonas fluorescens Exhibit Differential Toxicity Against Drosophila melanogaster

Science.gov (United States)

Three strains of Pseudomonas fluorescens were tested for toxicity to Drosophila melanogaster in an insect feeding assay. Insect eggs were placed on the surface of a non-nutritive agar plate supplemented with a food source that was non-inoculated or inoculated with P. fluorescens Pf0-1, SBW25, or Pf-...

Quantifying sublethal effects of glyphosate and Roundup® to Daphnia magna using a fluorescence based enzyme activity assay and video tracking

DEFF Research Database (Denmark)

Roslev, Peter; R. Hansen, Lone; Ørsted, Michael

Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum, non-selective herbicide formulations. The toxicity of this herbicide to non-target aquatic organisms such as Daphnia magna is often evaluated using conventional toxicity assays that focus...... on endpoints such as immobility and mortality. In this study, we investigated sublethal effects of glyphosate and Roundup® to D. magna using video tracking for quantifying behavioral changes, and a novel fluorescence based assay for measuring in vivo hydrolytic enzyme activity (FLEA assay). Roundup® exposure...... resulted in concentration-dependent inhibition of alkaline phosphatase activity in D. magna. The inhibition of alkaline phosphatase by Roundup® was temperature-dependent with lowest inhibition at 14 °C and greater inhibition at 20 and 26 °C. Exposure of D. magna to sublethal concentrations of glyphosate...

Plant responses to metal toxicity

Energy Technology Data Exchange (ETDEWEB)

Briat, J.F. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie moleculaire des plantes, CNRS, URA 2133; Lebrun, M. [Montpellier-2 Univ., 34 (France). Biochimie et physiologie vegetale appliquee

1999-01-01

Increased metal concentration in the soils, up to toxic levels, is becoming an important environmental problem. Safety rule evolution will require solutions in order to cope with food safety rules, and to freeze metal leakage from heavily metal-poisoned soils, such as those from industrial fallows. In this context, plants could serve to develop bio-assays in order to promote new standards, more realistic than the mass of a given metal per kg of soil, that does not consider the metal bio-disponibility. Plants could also be used for phyto-extraction and/or phyto-stabilization. To reach these objectives, a genetic approach could be useful to generate metal-tolerant plants with enough biomass. In this work is more particularly studied the plant responses to metal toxicity. Metal toxicity for living organisms involves oxidative and /or genotoxic mechanisms. Plant protection against metal toxicity occurs, at least in part, through control of root metal uptake and of long distance metal transport. Inside cells, proteins such as ferritins and metallothioneins, and glutathione-derived peptides named phyto-chelatins, participate in excess metal storage and detoxification. Low molecular weight organic molecules, mainly organic acids and amino acids and their derivatives, also play an important role in plant metal homeostasis. When these systems are overloaded, oxidative stress defense mechanisms are activated. Molecular and cellular knowledge of these processes will be necessary to improve plant metal resistance. Occurrence of naturally tolerant plants which hyper accumulate metals provides helpful tools for this research. (authors) 130 refs.

Comparative developmental toxicity of environmentally relevant oxygenated PAHs

International Nuclear Information System (INIS)

Knecht, Andrea L.; Goodale, Britton C.; Truong, Lisa; Simonich, Michael T.; Swanson, Annika J.; Matzke, Melissa M.; Anderson, Kim A.; Waters, Katrina M.; Tanguay, Robert L.

2013-01-01

Oxygenated polycyclic aromatic hydrocarbons (OPAHs) are byproducts of combustion and photo-oxidation of parent PAHs. OPAHs are widely present in the environment and pose an unknown hazard to human health. The developing zebrafish was used to evaluate a structurally diverse set of 38 OPAHs for malformation induction, gene expression changes and mitochondrial function. Zebrafish embryos were exposed from 6 to 120 h post fertilization (hpf) to a dilution series of 38 different OPAHs and evaluated for 22 developmental endpoints. AHR activation was determined via CYP1A immunohistochemistry. Phenanthrenequinone (9,10-PHEQ), 1,9-benz-10-anthrone (BEZO), xanthone (XAN), benz(a)anthracene-7,12-dione (7,12-B[a]AQ), and 9,10-anthraquinone (9,10-ANTQ) were evaluated for transcriptional responses at 48 hpf, prior to the onset of malformations. qRT-PCR was conducted for a number of oxidative stress genes, including the glutathione transferase(gst), glutathione peroxidase(gpx), and superoxide dismutase(sod) families. Bioenergetics was assayed to measure in vivo oxidative stress and mitochondrial function in 26 hpf embryos exposed to OPAHs. Hierarchical clustering of the structure-activity outcomes indicated that the most toxic of the OPAHs contained adjacent diones on 6-carbon moieties or terminal, para-diones on multi-ring structures. 5-carbon moieties with adjacent diones were among the least toxic OPAHs while the toxicity of multi-ring structures with more centralized para-diones varied considerably. 9,10-PHEQ, BEZO, 7,12-B[a]AQ, and XAN exposures increased expression of several oxidative stress related genes and decreased oxygen consumption rate (OCR), a measurement of mitochondrial respiration. Comprehensive in vivo characterization of 38 structurally diverse OPAHs indicated differential AHR dependency and a prominent role for oxidative stress in the toxicity mechanisms. - Highlights: • OPAHs are byproducts of combustion present in the environment. • OPAHs pose a largely

In situ synthesis of fluorescent magnetosomes using an organic membrane as a soft template.

Science.gov (United States)

Ke, Wenjing; Zhang, Juhua; An, Xueqin; Zhang, Bo

2017-05-04

A novel approach was presented for the in situ synthesis of fluorescent magnetosomes by biological mineralization and carbonization processes for the first time. The surface structures, magnetism and fluorescence were studied, and the cytotoxicity tests and fluorescent trace in liposomes were probed. The fluorescent magnetosomes exhibit not only unique fluorescence and ferromagnetic properties but also low toxicity and superior imaging capability.

An early developmental vertebrate model for nanomaterial safety: bridging cell-based and mammalian toxicity assessment.

Science.gov (United States)

Webster, Carl A; Di Silvio, Desire; Devarajan, Aarthi; Bigini, Paolo; Micotti, Edoardo; Giudice, Chiara; Salmona, Mario; Wheeler, Grant N; Sherwood, Victoria; Bombelli, Francesca Baldelli

2016-03-01

With the rise in production of nanoparticles (NPs) for an ever-increasing number of applications, there is an urgent need to efficiently assess their potential toxicity. We propose a NP hazard assessment protocol that combines mammalian cytotoxicity data with embryonic vertebrate abnormality scoring to determine an overall toxicity index. We observed that, after exposure to a range of NPs, Xenopus phenotypic scoring showed a strong correlation with cell based in vitro assays. Magnetite-cored NPs, negative for toxicity in vitro and Xenopus, were further confirmed as nontoxic in mice. The results highlight the potential of Xenopus embryo analysis as a fast screening approach for toxicity assessment of NPs, which could be introduced for the routine testing of nanomaterials.

Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

Science.gov (United States)

Cai, Zheng; Song, Xiangrong; Sun, Feng; Yang, Zhaoxiang; Hou, Shixiang; Liu, Zhongqiu

2011-12-01

Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

Concentration-dependent toxicity of iron oxide nanoparticles mediated by increased oxidative stress

Directory of Open Access Journals (Sweden)

Saba Naqvi

2010-11-01

Full Text Available Saba Naqvi1, Mohammad Samim2, MZ Abdin3, Farhan Jalees Ahmed4, AN Maitra5, CK Prashant6, Amit K Dinda61Faculty of Engineering and Interdisciplinary Sciences, 2Department of Chemistry, 3Department of Biotechnology, Faculty of Science, 4Department of Pharmaceutics, Faculty of Pharmacy, Jamia Hamdard, Hamdard University, 5Department of Chemistry, University of Delhi, 6Department of Pathology, All India Institute of Medical Sciences, New Delhi, IndiaAbstract: Iron oxide nanoparticles with unique magnetic properties have a high potential for use in several biomedical, bioengineering and in vivo applications, including tissue repair, magnetic resonance imaging, immunoassay, drug delivery, detoxification of biologic fluids, cell sorting, and hyperthermia. Although various surface modifications are being done for making these nonbiodegradable nanoparticles more biocompatible, their toxic potential is still a major concern. The current in vitro study of the interaction of superparamagnetic iron oxide nanoparticles of mean diameter 30 nm coated with Tween 80 and murine macrophage (J774 cells was undertaken to evaluate the dose- and time-dependent toxic potential, as well as investigate the role of oxidative stress in the toxicity. A 15–30 nm size range of spherical nanoparticles were characterized by transmission electron microscopy and zeta sizer. MTT assay showed >95% viability of cells in lower concentrations (25–200 µg/mL and up to three hours of exposure, whereas at higher concentrations (300–500 µg/mL and prolonged (six hours exposure viability reduced to 55%–65%. Necrosis-apoptosis assay by propidium iodide and Hoechst-33342 staining revealed loss of the majority of the cells by apoptosis. H2DCFDDA assay to quantify generation of intracellular reactive oxygen species (ROS indicated that exposure to a higher concentration of nanoparticles resulted in enhanced ROS generation, leading to cell injury and death. The cell membrane injury

In-situ bioremediation at the French Limited Site

International Nuclear Information System (INIS)

Woodward, R.; Ramsden, D.

1990-01-01

In situ biodegradation of petrochemical wastes at the French Limited Superfund Site was stimulated by providing the appropriate pH, essential nutrients, oxygen, and substrate availability. Fourteen wastewater treatment parameters, plus toxicity, were monitored to document the program of bioremediation. Periodic, organic priority pollutant analysis of mixed liquor, settled sludges and subsoils provided data for kinetics interpretation and half life calculation. The half lives of thirteen PAH compounds ranged from 27 to 46 days, in contrast to the degradation rate, in months, reported for these compounds in LTUs. An ambitious air monitoring program measured fugitive emissions at lagoon side, fenceline, and from the lagoon surface by floating flux chamber. The amount of volatiles lost never exceeded 1/2 of the OSHA 8 hr TLV and it could be readily managed by adjusting the intensity and frequency of mixing and aeration. The demonstration confirmed the feasibility of in situ bioremediation and led to one of the first US EPA Record of Decisions to use bioremediation for cleanup of a large Superfund site. A consent Decree outlining the site remedial action program was signed by the PRP task group and published in the Federal Register. This represents a landmark project for in situ bioremediation and has established precedence for use of this technology at CERCLA and RCRA sites nationwide

Non-animal Replacements for Acute Toxicity Testing.

Science.gov (United States)

Barker-Treasure, Carol; Coll, Kevin; Belot, Nathalie; Longmore, Chris; Bygrave, Karl; Avey, Suzanne; Clothier, Richard

2015-07-01

Current approaches to predicting adverse effects in humans from acute toxic exposure to cosmetic ingredients still heavily necessitate the use of animals under EU legislation, particularly in the context of the REACH system, when cosmetic ingredients are also destined for use in other industries. These include the LD50 test, the Up-and-Down Procedure and the Fixed Dose Procedure, which are regarded as having notable scientific deficiencies and low transferability to humans. By expanding on previous in vitro tests, such as the animal cell-based 3T3 Neutral Red Uptake (NRU) assay, this project aims to develop a truly animal-free predictive test for the acute toxicity of cosmetic ingredients in humans, by using human-derived cells and a prediction model that does not rely on animal data. The project, funded by Innovate UK, will incorporate the NRU assay with human dermal fibroblasts in animal product-free culture, to generate an in vitro protocol that can be validated as an accepted replacement for the currently available in vivo tests. To date, the project has successfully completed an assessment of the robustness and reproducibility of the method, by using sodium lauryl sulphate (SLS) as a positive control, and displaying analogous results to those of the original studies with mouse 3T3 cells. Currently, the testing of five known ingredients from key groups (a surfactant, a preservative, a fragrance, a colour and an emulsifier) is under way. The testing consists of initial range-finding runs followed by three valid runs of a main experiment with the appropriate concentration ranges, to generate IC50 values. Expanded blind trials of 20 ingredients will follow. Early results indicate that this human cell-based test holds the potential to replace aspects of in vivo animal acute toxicity testing, particularly with reference to cosmetic ingredients. 2015 FRAME.

Toxicity of Graphene Shells, Graphene Oxide, and Graphene Oxide Paper Evaluated with Escherichia coli Biotests

Directory of Open Access Journals (Sweden)

Ludmila V. Efremova

2015-01-01

Full Text Available The plate-like graphene shells (GS produced by an original methane pyrolysis method and their derivatives graphene oxide (GO and graphene oxide paper (GO-P were evaluated with luminescent Escherichia coli biotests and additional bacterial-based assays which together revealed the graphene-family nanomaterials’ toxicity and bioactivity mechanisms. Bioluminescence inhibition assay, fluorescent two-component staining to evaluate cell membrane permeability, and atomic force microscopy data showed GO expressed bioactivity in aqueous suspension, whereas GS suspensions and the GO-P surface were assessed as nontoxic materials. The mechanism of toxicity of GO was shown not to be associated with oxidative stress in the targeted soxS::lux and katG::lux reporter cells; also, GO did not lead to significant mechanical disruption of treated bacteria with the release of intracellular DNA contents into the environment. The well-coordinated time- and dose-dependent surface charge neutralization and transport and energetic disorders in the Escherichia coli cells suggest direct membrane interaction, internalization, and perturbation (i.e., “membrane stress” as a clue to graphene oxide’s mechanism of toxicity.

Toxicity of Graphene Shells, Graphene Oxide, and Graphene Oxide Paper Evaluated with Escherichia coli Biotests.

Science.gov (United States)

Efremova, Ludmila V; Vasilchenko, Alexey S; Rakov, Eduard G; Deryabin, Dmitry G

2015-01-01

The plate-like graphene shells (GS) produced by an original methane pyrolysis method and their derivatives graphene oxide (GO) and graphene oxide paper (GO-P) were evaluated with luminescent Escherichia coli biotests and additional bacterial-based assays which together revealed the graphene-family nanomaterials' toxicity and bioactivity mechanisms. Bioluminescence inhibition assay, fluorescent two-component staining to evaluate cell membrane permeability, and atomic force microscopy data showed GO expressed bioactivity in aqueous suspension, whereas GS suspensions and the GO-P surface were assessed as nontoxic materials. The mechanism of toxicity of GO was shown not to be associated with oxidative stress in the targeted soxS::lux and katG::lux reporter cells; also, GO did not lead to significant mechanical disruption of treated bacteria with the release of intracellular DNA contents into the environment. The well-coordinated time- and dose-dependent surface charge neutralization and transport and energetic disorders in the Escherichia coli cells suggest direct membrane interaction, internalization, and perturbation (i.e., "membrane stress") as a clue to graphene oxide's mechanism of toxicity.

Validation of visualized transgenic zebrafish as a high throughput model to assay bradycardia related cardio toxicity risk candidates.

Science.gov (United States)

Wen, Dingsheng; Liu, Aiming; Chen, Feng; Yang, Julin; Dai, Renke

2012-10-01

Drug-induced QT prolongation usually leads to torsade de pointes (TdP), thus for drugs in the early phase of development this risk should be evaluated. In the present study, we demonstrated a visualized transgenic zebrafish as an in vivo high-throughput model to assay the risk of drug-induced QT prolongation. Zebrafish larvae 48 h post-fertilization expressing green fluorescent protein in myocardium were incubated with compounds reported to induce QT prolongation or block the human ether-a-go-go-related gene (hERG) K⁺ current. The compounds sotalol, indapaminde, erythromycin, ofoxacin, levofloxacin, sparfloxacin and roxithromycin were additionally administrated by microinjection into the larvae yolk sac. The ventricle heart rate was recorded using the automatic monitoring system after incubation or microinjection. As a result, 14 out of 16 compounds inducing dog QT prolongation caused bradycardia in zebrafish. A similar result was observed with 21 out of 26 compounds which block hERG current. Among the 30 compounds which induced human QT prolongation, 25 caused bradycardia in this model. Thus, the risk of compounds causing bradycardia in this transgenic zebrafish correlated with that causing QT prolongation and hERG K⁺ current blockage in established models. The tendency that high logP values lead to high risk of QT prolongation in this model was indicated, and non-sensitivity of this model to antibacterial agents was revealed. These data suggest application of this transgenic zebrafish as a high-throughput model to screen QT prolongation-related cardio toxicity of the drug candidates. Copyright © 2012 John Wiley & Sons, Ltd.

Hydrous pyrolysis/oxidation process for in situ destruction of chlorinated hydrocarbon and fuel hydrocarbon contaminants in water and soil

Science.gov (United States)

Knauss, Kevin G.; Copenhaver, Sally C.; Aines, Roger D.

2000-01-01

In situ hydrous pyrolysis/oxidation process is useful for in situ degradation of hydrocarbon water and soil contaminants. Fuel hydrocarbons, chlorinated hydrocarbons, polycyclic aromatic hydrocarbons, petroleum distillates and other organic contaminants present in the soil and water are degraded by the process involving hydrous pyrolysis/oxidation into non-toxic products of the degradation. The process uses heat which is distributed through soils and water, optionally combined with oxygen and/or hydrocarbon degradation catalysts, and is particularly useful for remediation of solvent, fuel or other industrially contaminated sites.

Detection of Epstein Barr virus in formalin-fixed paraffin tissues by fluorescent direct in situ PCR

Directory of Open Access Journals (Sweden)

N Marziliano

2009-06-01

Full Text Available Specific viral laboratory diagnosis of primary Epstein-Barr Virus (EBV infection is usually based on antibody-detection assays. However, molecular detection is also considered the reference standard assay for diagnosis of central nervous system infections and of most cases of nasopharyngeal carcinoma (NPC. One-step or nested polymerase chain reaction (PCR has rapidly replaced immunological assays based on virus-specific Ig antibodies for the laboratory diagnosis of Herpesvirus infections, even if serological methods are considered an additional tool for defining clinical diagnosis. In this article, we will present a rapid, sensitive and robust molecular tool for the viral detection of EBV (EBNA-1 within tissue specimens by making use of in situ PCR (IS-PCR.

Assessment of toxicity and genotoxicity of the reactive azo dyes Remazol Black B and Remazol Orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects

International Nuclear Information System (INIS)

Pinheiro, Alessandro de Sa

2011-01-01

The textile industries play an important role in national and global economy. But, their activities are considered potentially polluting. The use of large volumes of water and the production of colored wastewater with high organic matter are among the main issues raised, especially during the stage of dyeing and washing of the textile process. The reactive azo dyes are the main colors used in the industry for dyeing of cotton in Brazil and worldwide. Because of its low setting and variations in the fiber production process, about 30% of the initial concentration used in the dyeing baths are lost and will compose the final effluent. These compounds have a low biodegradability, are highly soluble in water and therefore are not completely removed by conventional biological processes. In addition, other processes do not promote degradation but the transference to solid environment. The dyes discarded without treatment in the water body can cause aesthetic modifications, alter photosynthesis and gas solubility, as well as being toxic and genotoxic. The main objectives of this study were to evaluate the toxicity and genotoxicity of two reactive azo dyes (Remazol Black B - RPB and Remazol Orange 3R - R3AR) and the percentage of color and toxicity reduction after the use of electron beam radiation. The acute toxicity assays performed with Vibrio fischeri, Daphnia similis and Biomphalaria glabrata showed different response patterns for dyes. The different chemical forms of dyes were slightly toxic to Vibrio fischeri and only the RPB dye (vinylsulphone) was toxic (EC50 15min = 6,23 mg L-1). In tests with Daphnia similis, the dye RPB was slightly toxic in its pattern form, sulphatoethylsulphone, (CE50 48h = 91,25 mg L -1 ) and showed no toxicity in other chemical forms. However, the RA3R dye was toxic to the dafnids and the vinylsulphone form very toxic (EC50 48h = 0,54 mg L-1). No toxicity was observed in Biomphalaria glabrata assays. Chronic toxicity was assessed with the

The effect of laurel leaf extract against toxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in cultured rat hepatocytes.

Science.gov (United States)

Turkez, Hasan; Geyikoglu, Fatime

2011-12-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a very toxic environmental pollutant that raises great public concern about its impact on human health. Recent studies indicate that laurel leaf extract exhibits antioxidant properties that can counter the toxic effects of certain compounds in the liver. The aim of this study was to assess how effective LE is against the toxicity of TCDD in a primary culture of rat hepatocytes. The extract (50 mg L(-1), 100 mg L(-1), and 200 mg L(-1)) was added to cultures alone or with TCDD (1.61 mg L(-1) and 3.22 mg L(-1)) for 48 hours. Cell viability was measured using the [3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide] (MTT) assay and the lactate dehydrogenase (LDH) cytotoxicity assay, while oxidative damage was assessed by measuring total antioxidant capacity (TAC) and total oxidative stress (TOS). DNA damage was also analysed using the micronucleus (MN) assay of the cultured hepatocytes. TCDD alone lowered, and laurel extract had no effect on cell viability. TCDD also increased TOS and significantly decreased TAC. It significantly increased the frequency of micronucleated hepatocytes in a dose-dependent manner. In cultures exposed to LE alone, TOS did not change and TAC significantly increased in a dose-dependent manner. Added to TCDD, laurel countered its toxic effects and showed protective effects against TCDD-mediated DNA damage. This points to the therapeutic potential of laurel against TCDD toxicity in the liver.

In situ gel systems as 'smart' carriers for sustained ocular drug delivery.

Science.gov (United States)

Agrawal, Ashish Kumar; Das, Manasmita; Jain, Sanyog

2012-04-01

In situ gel systems refer to a class of novel delivery vehicles, composed of natural, semisynthetic or synthetic polymers, which present the unique property of sol-gel conversion on receipt of biological stimulus. The present review summarizes the latest developments in in situ gel technology, with regard to ophthalmic drug delivery. Starting with the mechanism of ocular absorption, the review expands on the fabrication of various polymeric in situ gel systems, made up of two or more polymers presenting multi-stimuli sensitivity, coupled with other interesting features, such as bio-adhesion, enhanced penetration or sustained release. Various key issues and challenges in this area have been addressed and critically analyzed. The advent of in situ gel systems has inaugurated a new transom for 'smart' ocular delivery. By virtue of possessing stimuli-responsive phase transition properties, these systems can easily be administered into the eye, similar to normal eye drops. Their unique gelling properties endow them with special features, such as prolonged retention at the site of administration, followed by sustained drug release. Despite the superiority of these systems as compared with conventional ophthalmic formulations, further investigations are necessary to address the toxicity issues, so as to minimize regulatory hurdles during commercialization.

Compound toxicity screening and structure-activity relationship modeling in Escherichia coli.

Science.gov (United States)

Planson, Anne-Gaëlle; Carbonell, Pablo; Paillard, Elodie; Pollet, Nicolas; Faulon, Jean-Loup

2012-03-01

Synthetic biology and metabolic engineering are used to develop new strategies for producing valuable compounds ranging from therapeutics to biofuels in engineered microorganisms. When developing methods for high-titer production cells, toxicity is an important element to consider. Indeed the production rate can be limited due to toxic intermediates or accumulation of byproducts of the heterologous biosynthetic pathway of interest. Conversely, highly toxic molecules are desired when designing antimicrobials. Compound toxicity in bacteria plays a major role in metabolic engineering as well as in the development of new antibacterial agents. Here, we screened a diversified chemical library of 166 compounds for toxicity in Escherichia coli. The dataset was built using a clustering algorithm maximizing the chemical diversity in the library. The resulting assay data was used to develop a toxicity predictor that we used to assess the toxicity of metabolites throughout the metabolome. This new tool for predicting toxicity can thus be used for fine-tuning heterologous expression and can be integrated in a computational-framework for metabolic pathway design. Many structure-activity relationship tools have been developed for toxicology studies in eukaryotes [Valerio (2009), Toxicol Appl Pharmacol, 241(3): 356-370], however, to the best of our knowledge we present here the first E. coli toxicity prediction web server based on QSAR models (EcoliTox server: http://www.issb.genopole.fr/∼faulon/EcoliTox.php). Copyright © 2011 Wiley Periodicals, Inc.

Comparing in situ removal strategies for improving styrene bioproduction.

Science.gov (United States)

McKenna, Rebekah; Moya, Luis; McDaniel, Matthew; Nielsen, David R

2015-01-01

As an important conventional monomer compound, the biological production of styrene carries significant promise with respect to creating novel sustainable materials. Since end-product toxicity presently limits styrene production by previously engineered Escherichia coli, in situ product removal by both solvent extraction and gas stripping were explored as process-based strategies for circumventing its inhibitory effects. In solvent extraction, the addition of bis(2-ethylhexyl)phthalate offered the greatest productivity enhancement, allowing net volumetric production of 836 ± 64 mg/L to be reached, representing a 320 % improvement over single-phase cultures. Gas stripping rates, meanwhile, were controlled by rates of bioreactor agitation and, to a greater extent, aeration. A periodic gas stripping protocol ultimately enabled up to 561 ± 15 mg/L styrene to be attained. Lastly, by relieving the effects of styrene toxicity, new insight was gained regarding subsequent factors limiting its biosynthesis in E. coli and strategies for future strain improvement are discussed.

Efficacy and toxicity of self-polishing biocide-free antifouling paints

International Nuclear Information System (INIS)

Loeschau, Margit; Kraetke, Renate

2005-01-01

The ban on harmful substances in antifouling paints requires the development of new antifouling strategies. Alternatives should be as effective as conventional paints but of lower toxicity. In the present study two commercially available, self-polishing antifouling paints were examined in order to get information on their antifouling properties and toxicological potential. Efficacy was shown in settlement assays with the marine barnacle species Balanus amphitrite, however, efficacy was related to toxic effects observed on target and non-target organisms. Toxicity of the paint extracts was concentration-dependent and differed according to the paint and the species investigated. Toxicity could at least partially be attributed to zinc leached from the paints. Effects of a water-soluble paint were more pronounced in larvae of B. amphitrite, Artemia salina and in the green algae Dunaliella tertiolecta. Embryos of the freshwater species Danio rerio and Vibrio fisheri were more affected by a paint based on organic solvents. - For alternative antifouling paints efficacy as well as adverse effects on non-target organisms and the aquatic environment should be carefully assessed

4-Alkynylphenylsilatranes: Insecticidal activity, mammalian toxicity, and mode of action

International Nuclear Information System (INIS)

Horsham, M.A.; Palmer, C.J.; Cole, L.M.; Casida, J.E.

1990-01-01

4-Ethynyl- and 4-(prop-1-ynyl)phenylsilatranes [N(CH 2 CH 2 O) 3 SiR, R = C 6 H 4 -4-C triple-bond CH or C 6 H 4 -4-C triple-bond CCH 3 ] are highly toxic to houseflies (pretreated with piperonyl butoxide) and milkweed bugs (topical LD 50 s 3-14 μg/g) and to mice (intraperitoneal LD 50 s 0.4-0.9 mg/kg), and they are moderately potent inhibitors of the [ 35 S]-tert-butylbicyclophosphorothionate or TBPS binding site (GABA-gated chloride channel) of mouse brain membranes. Scatchard analysis indicates noncompetitive interaction of 4-ethynylphenylsilatrane with the TBPS binding site. Phenylsilatrane analogues with 4-substituents of H, CH 3 , Cl, Br, and C triple-bond CSi(CH 3 ) 3 are highly toxic to mice but have little or no activity in the insect and receptor assays. Radioligand binding studies with [4- 3 H]phenylsilatrane failed to reveal a specific binding site in mouse brain. Silatranes with R = H, CH 3 , CH 2 Cl, CH double-bond CH 2 , OCH 2 CH 3 , and C 6 H 4 -4-CH 2 CH 3 are of little or no activity in the insect and mouse toxicity and TBPS binding site assays as are the trithia and monocyclic analogues of phenylsilatrane. 4-Alkynylphenylsilatranes are new probes to examine the GABA receptor-ionophore complex of insects and mammals

Some heterocyclic aromatic compounds are Ah receptor agonists in the DR-CALUX assay and the EROD assay with RTL-W1 cells.

Science.gov (United States)

Hinger, Gunnar; Brinkmann, Markus; Bluhm, Kerstin; Sagner, Anne; Takner, Helena; Eisenträger, Adolf; Braunbeck, Thomas; Engwall, Magnus; Tiehm, Andreas; Hollert, Henner

2011-09-01

Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil, marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays. To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two bioassays. The present study focuses on the identification and quantification of dioxin-like effects of 12 NSO-HET using the DR-CALUX assay, and the 7-ethoxyresorufin-O-deethylase (EROD) assay with the permanent fish liver cell line RTL-W1. Changes of the total medium compound concentrations during the test procedure due to, e.g., sorption or volatilization were quantified using GC/MS. The NSO-HET benzofuran, 2,3-dimethylbenzofuran, dibenzofuran, dibenzothiophen, acridine, xanthene, and carbazole caused a response in the DR-CALUX assay. Only benzofuran and 2,3-dimethylbenzofuran were also positive in the EROD assay. All other compounds were inactive in the EROD assay. Relative potency (REP) values ranged from (2.80 ± 1.32) · 10(-8) to (3.26 ± 2.03) · 10(-6) in the DR-CALUX and from (3.26 ± 0.91) · 10(-7) to (4.87 ± 1.97) · 10(-7) in the EROD assay. The REP values were comparable to those of larger polycyclic aromatic hydrocarbons, e.g., fluoranthene and pyrene. Thus, and because of the ubiquitous distribution of heterocyclic aromatic compounds in the environment, the provided data will further facilitate the bioanalytical and analytical characterization of environmental samples towards these toxicants.

Involvement of the histamine H4 receptor in clozapine-induced hematopoietic toxicity: Vulnerability under granulocytic differentiation of HL-60 cells

International Nuclear Information System (INIS)

Goto, Aya; Mouri, Akihiro; Nagai, Tomoko; Yoshimi, Akira; Ukigai, Mako; Tsubai, Tomomi; Hida, Hirotake; Ozaki, Norio; Noda, Yukihiro

2016-01-01

Clozapine is an effective antipsychotic for treatment-resistant schizophrenia, but can cause fatal hematopoietic toxicity as agranulocytosis. To elucidate the mechanism of hematopoietic toxicity induced by clozapine, we developed an in vitro assay system using HL-60 cells, and investigated the effect on hematopoiesis. HL-60 cells were differentiated by all-trans retinoic acid (ATRA) into three states according to the following hematopoietic process: undifferentiated HL-60 cells, those undergoing granulocytic ATRA-differentiation, and ATRA-differentiated granulocytic cells. Hematopoietic toxicity was evaluated by analyzing cell survival, cell proliferation, granulocytic differentiation, apoptosis, and necrosis. In undifferentiated HL-60 cells and ATRA-differentiated granulocytic cells, both clozapine (50 and 100 μM) and doxorubicin (0.2 µM) decreased the cell survival rate, but olanzapine (1–100 µM) did not. Under granulocytic differentiation for 5 days, clozapine, even at a concentration of 25 μM, decreased survival without affecting granulocytic differentiation, increased caspase activity, and caused apoptosis rather than necrosis. Histamine H 4 receptor mRNA was expressed in HL-60 cells, whereas the expression decreased under granulocytic ATRA-differentiation little by little. Both thioperamide, a histamine H 4 receptor antagonist, and DEVD-FMK, a caspase-3 inhibitor, exerted protection against clozapine-induced survival rate reduction, but not of live cell counts. 4-Methylhistamine, a histamine H 4 receptor agonist, decreased the survival rate and live cell counts, as did clozapine. HL-60 cells under granulocytic differentiation are vulnerable under in vitro assay conditions to hematopoietic toxicity induced by clozapine. Histamine H 4 receptor is involved in the development of clozapine-induced hematopoietic toxicity through apoptosis, and may be a potential target for preventing its occurrence through granulocytic differentiation. - Highlights: • HL-60

Insecticide toxicity to Hyalella curvispina in runoff and stream water within a soybean farm (Buenos Aires, Argentina).

Science.gov (United States)

Mugni, H; Ronco, A; Bonetto, C

2011-03-01

Toxicity to the locally dominant amphipod Hyalella curvispina was assessed in a first-order stream running through a cultivated farm. Cypermethrin, chlorpyrifos, endosulfan and glyphosate were sprayed throughout the studied period. Toxicity was assayed under controlled laboratory conditions with runoff and stream water samples taken from the field under steady state and flood conditions. Ephemeral toxicity pulses were observed as a consequence of farm pesticide applications. After pesticide application, runoff water showed 100% mortality to H. curvispina for 1 month, but no mortality thereafter. Toxicity persistence was shortest in stream water, intermediate in stream sediments and longest in soil samples. Runoff had a more important toxicity effect than the exposure to direct aerial fumigation. The regional environmental features determining fast toxicity dissipation are discussed. Copyright © 2010. Published by Elsevier Inc.

The benzoquinone-mediated electrochemical microbial biosensor for water biotoxicity assay

International Nuclear Information System (INIS)

Li, Jiuming; Yu, Yuan; Wang, Yuning; Qian, Jun; Zhi, Jinfang

2013-01-01

Graphical abstract: The mediator can participate in microorganism respiration, accept the electrons from respiratory chains, and therefore be reduced by microorganism. The re-oxidization currents of mediators on electrode can reflect the microbial activity, and when respiration is suppressed by toxicants, it can be detected by the resulting change of currents. Unlike other biotoxicity tests, which record the toxic effect after a fixed time for incubation of biocomponents and toxicants, this mediated whole cell biosensor can provide a real-time monitor of the microbial activity during the measurement. -- Abstract: A simple mediated microbial biosensor providing real-time monitoring of water quality and evaluation of biotoxicity was fabricated by entrapping Escherichia coli (E. coli) cells in gelatin on glassy carbon electrode with benzoquinone as the redox mediator. The biotoxicity assay was based on the respiratory activity of E. coli cells estimated by the oxidation current of microbially reduced benzoquinone. The neutrality and lipophilicity rendered benzoquinone better efficiency than ferricyanide in mediated microbial reactions. After the optimization of preparation conditions, the prepared microbial biosensors have measured several common toxicants with different concentrations. In addition, the biotoxicity of binary mixtures of heavy metals and wastewater were investigated. The fabricated biosensor exhibited good repeatability and stability in the biotoxicity measurements

pH-Responsive, Self-Sacrificial Nanotheranostic Agent for Potential In Vivo and In Vitro Dual Modal MRI/CT Imaging, Real-Time, and In Situ Monitoring of Cancer Therapy.

Science.gov (United States)

Yue, Ludan; Wang, Jinlong; Dai, Zhichao; Hu, Zunfu; Chen, Xue; Qi, Yafei; Zheng, Xiuwen; Yu, Dexin

2017-02-15

Multifunctional nanotheranostic agents have been highly commended due to the application to image-guided cancer therapy. Herein, based on the chemically disordered face centered cubic (fcc) FePt nanoparticles (NPs) and graphene oxide (GO), we develop a pH-responsive FePt-based multifunctional theranostic agent for potential in vivo and in vitro dual modal MRI/CT imaging and in situ cancer inhibition. The fcc-FePt will release highly active Fe ions due to the low pH in tumor cells, which would catalyze H 2 O 2 decomposition into reactive oxygen species (ROS) within the cells and further induce cancer cell apoptosis. Conjugated with folic acid (FA), the iron platinum-dimercaptosuccinnic acid/PEGylated graphene oxide-folic acid (FePt-DMSA/GO-PEG-FA) composite nanoassemblies (FePt/GO CNs) could effectively target and show significant toxicity to FA receptor-positive tumor cells, but no obvious toxicity to FA receptor-negative normal cells, which was evaluated by WST-1 assay. The FePt-based multifunctional nanoparticles allow real-time monitoring of Fe release by T 2 -weighted MRI, and the selective contrast enhancement in CT could be estimated in vivo after injection. The results showed that FePt-based NPs displayed excellent biocompatibility and favorable MRI/CT imaging ability in vivo and in vitro. Meanwhile, the decomposition of FePt will dramatically decrease the T 2 -weighted MRI signal and increase the ROS signal, which enables real-time and in situ visualized monitoring of Fe release in tumor cells. In addition, the self-sacrificial decomposition of fcc-FePt will be propitious to the self-clearance of the as-prepared FePt-based nanocomposite in vivo. Therefore, the FePt/GO CNs could serve as a potential multifunctional theranostic nanoplatform of MRI/CT imaging guided cancer diagnosis and therapy in the clinic.

Test systems to identify reproductive toxicants.

Science.gov (United States)

Riecke, K; Stahlmann, R

2000-09-01

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

Increased DNA damage in blood cells of rat treated with lead as assessed by comet assay

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Mohammad Arif

2008-06-01

Full Text Available A growing body of evidence suggests that oxidative stress is the key player in the pathogenesis of lead-induced toxicity. The present study investigated lead induced oxidative DNA damage, if any in rat blood cells by alkaline comet assay. Lead was administered intraperitoneally to rats at doses of 25, 50 and 100 mg/kg body weight for 5 days consecutively. Blood collected on day six from sacrificed lead-treated rats was used to assess the extent of DNA damage by comet assay which entailed measurement of comet length, olive tail moment, tail DNA (% and tail length. The results showed that treatment with lead significantly increased DNA damage in a dose-dependent manner. Therefore, our data suggests that lead treatment is associated with oxidative stress-induced DNA damage in rat blood cells which could be used as an early bio-marker of lead-toxicity.

In Situ Distribution And Speciation Of Toxic Copper, Nickel, And Zinc In Hydrated Roots Of Cowpea

Science.gov (United States)

The phytotoxicity of trace metals is of global concern due to contamination of the landscape by human activities. Using synchrotron-based X-ray fluorescence microscopy and X-ray absorption spectroscopy, the distribution and speciation of Cu, Ni, and Zn was examined in situ

Toward toxicity testing of nanomaterials in the 21st century: a paradigm for moving forward.

Science.gov (United States)

Lai, David Y

2012-01-01

A challenge-facing hazard identification and safety evaluation of engineered nanomaterials being introduced to market is the diversity and complexity of the types of materials with varying physicochemical properties, many of which can affect their toxicity by different mechanisms. In general, in vitro test systems have limited usefulness for hazard identification of nanoparticles due to various issues. Meanwhile, conducting chronic toxicity/carcinogenicity studies in rodents for every new nanomaterial introduced into the commerce is impractical if not impossible. New toxicity testing systems which rely on predictive, high-throughput technologies may be the ultimate goal of evaluating the potential hazard of nanomaterials. However, at present, this approach alone is unlikely to succeed in evaluating the toxicity of the wide array of nanomaterials and requires validation from in vivo studies. This article proposes a paradigm for toxicity testing and elucidation of the molecular mechanisms of reference materials for specific nanomaterial classes/subclasses using short-term in vivo animal studies in conjunction with high-throughput screenings and mechanism-based short-term in vitro assays. The hazard potential of a particular nanomaterial can be evaluated by conducting only in vitro high-throughput assays and mechanistic studies and comparing the data with those of the reference materials in the specific class/subclass-an approach in line with the vision for 'Toxicity Testing in the 21st Century' of chemicals. With well-designed experiments, testing nanomaterials of varying/selected physicochemical parameters may be able to identify the physicochemical parameters contributing to toxicity. The data so derived could be used for the development of computer model systems to predict the hazard potential of specific nanoparticles based on property-activity relationships. Copyright © 2011 John Wiley & Sons, Inc.

Assessment of the safety of hydrogenated resistant maltodextrin: reverse mutation assay, acute and 90-day subchronic repeated oral toxicity in rats, and acute no-effect level for diarrhea in humans.

Science.gov (United States)

Yoshikawa, Yuko; Kishimoto, Yuka; Tagami, Hiroyuki; Kanahori, Sumiko

2013-01-01

A series of safety assessments were performed on hydrogenated resistant maltodextrin prepared by converting the reducing terminal glucose of resistant maltodextrin into sorbitol. The reverse mutation assay did not show mutagenicity. Acute and 90-day subchronic oral toxicity studies in rats showed no death was observed in any groups, including the group receiving the highest single dose of 10 g/kg body weight or the highest dose of 5 g/kg body weight per day for 90 days. Mucous or watery stools were observed in the hydrogenated resistant maltodextrin treatment group on the acute study, which were transient and were associated with the osmotic pressure caused by intake of the high concentrations. Subchronic study showed dose-dependent increases in the weights of cecum alone, cecal contents alone, and cecum with cecal contents as well as hypertrophy of the cecal mucosal epithelium, which are considered to be common physiological responses after intake of indigestible carbohydrates. These results indicated that the no observed adverse effect level (NOAEL) of hydrogenated resistant maltodextrin was 10 g/kg body weight or more on the acute oral toxicity study and 5.0 g/kg body weight/day or more on the 90-day subchronic repeated oral toxicity study in rats. Further study performed in healthy adult humans showed that the acute no-effect level of hydrogenated resistant maltodextrin for diarrhea was 0.8 g/kg body weight for men and more than 1.0 g/kg body weight for women. The results of the current safety assessment studies suggest that hydrogenated resistant maltodextrin is safe for human consumption.

Assays of residual antibiotics after treatment of γ-ray and UV irradiation

International Nuclear Information System (INIS)

Shin, Ji Hye; Nam, Ji Hyun; Lee, Dong Hun; Yu, Seung Ho; Lee, Myun Joo

2010-01-01

The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and γ-ray irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after γ-ray and UV irradiation. Most samples were degraded by γ-ray irradiation (1 ∼ 2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with γ-ray and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of γ-ray irradiated cephradine measured by AMS test were 2 times higher than of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that γ-ray irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation

Comparison of the toxicity of fluoridation compounds in the nematode Caenorhabditis elegans.

Science.gov (United States)

Rice, Julie R; Boyd, Windy A; Chandra, Dave; Smith, Marjolein V; Den Besten, Pamela K; Freedman, Jonathan H

2014-01-01

Fluorides are commonly added to drinking water in the United States to decrease the incidence of dental caries. Silicofluorides, such as sodium hexafluorosilicate (Na2 SiF6 ) and fluorosilicic acid (H2 SiF6 ), are mainly used for fluoridation, although fluoride salts such as sodium fluoride (NaF) are also used. Interestingly, only the toxicity of NaF has been examined and not that of the more often used silicofluorides. In the present study, the toxicities of NaF, Na2 SiF6 , and H2 SiF6 were compared. The toxicity of these fluorides on the growth, feeding, and reproduction in the alternative toxicological testing organism Caenorhabditis elegans was examined. Exposure to these compounds produced classic concentration-response toxicity profiles. Although the effects of the fluoride compounds varied among the 3 biological endpoints, no differences were found between the 3 compounds, relative to the fluoride ion concentration, in any of the assays. This suggests that silicofluorides have similar toxicity to NaF. © 2013 SETAC.

Toxicity and behavioral effects of nootkatone, 1,10-dihydronootkatone, and tetrahydronootkatone to the formosan subterranean termite (Isoptera: Rhinotermitidae).

Science.gov (United States)

Ibrahim, Sanaa A; Henderson, Gregg; Zhu, Betty C R; Fei, Huixin; Laine, Roger A

2004-02-01

Toxicity and behavioral effects of nootkatone and two of its derivatives, 1,10-dihydronootkatone and tetrahydronootkatone, to Coptotermes formosanus Shiraki were investigated on workers from two different colonies by using topical application assays, repellency assays, and sand barrier assays. The acute toxicity of the nootkatones on workers from both colonies increased as the saturation of the molecule increased, but the difference was significant for only one colony. The results of the repellency assays showed a similar trend of efficiency; the threshold concentration for significant repellency was four-fold higher in nootkatone treatments (50 ppm) than in the reduced derivatives 1,10-dihydronootkatone or tetrahydronootkatone (12.5 ppm). In sand barrier assays, a concentration of 100 ppm of any of the three chemicals significantly reduced termite survival, tunnel building, and food consumption after a 12-d exposure. Termites preexposed to 100 ppm nootkatone-treated sand and placed in containers without nootkatone for 15 d continued to exhibit abnormal feeding and digging behaviors; survivorship, tunneling, and feeding activities were significantly reduced by 83.5, 63.2, and 95.4%, respectively. Termites pretreated for 12 d at concentrations of 50 and 75 ppm nootkatone and tetrahydronootkatone returned to normal digging activity after they were removed from the treatments, but their feeding activity was significantly reduced.

In-situ degradation of sulphur mustard using (1R)-(-)-(camphorylsulphonyl) oxaziridine impregnated adsorbents

Energy Technology Data Exchange (ETDEWEB)

Sharma, Abha, E-mail: abha_052002@yahoo.co.in [Industrial Toxicology Research Centre, Mahatam Gandhi Marg, Lucknow, UP (India); Saxena, Amit; Singh, Beer [Defence Research and Development Establishment, Jhansi Road, Gwalior, MP (India)

2009-12-30

Bis-2-chloroethyl sulphide (sulphur mustard or HD) is an extremely toxic and persistent chemical warfare agent. For in-situ degradation of HD and its analogues (simulants), i.e., dibutyl sulphide (DBS) and ethyl 2-hydroxyethyl sulphide (HEES), different adsorbents systems loaded with (1R)-(-)-(camphorylsulphonyl) oxaziridine were prepared. Solution of sulphur mustard and its simulants was prepared in carbon tetrachloride and taken for uniform adsorption on the impregnated systems using incipient volume. Degradation kinetics monitored by GC/FID were found to be first-order. The half-life of degradation reactions for simulants was obtained in less than 30 and for HD in 120 min. From the studied kinetics it was observed that reaction was very rapid with simulants and decreased rate was found for HD. The order of reactivity of MgO/Oxa system for HD and simulants was found to be DBS > HEES > HD. Reaction products of the oxidation reaction of simulants and HD on adsorbents were extracted in dichloromethane and analysed by GC-MS. The products were found to be non-toxic sulphoxide. The objective of the study is to develop a reactive adsorbent for in-situ degradation of sulphur mustard which could be used in nuclear biological and chemical (NBC) filtration systems.

Evaluation on diminishing effects of DNA damaging potential by humic substances using the bacillus subtilis rec-assay; Karekusakin rec-assay wo mochiita fuminsan ni yoru DNA sonshosei kaizen koka no kento

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, H.; Takigami, H.; Shimizu, Y.; Matsui, S. [Kyoto University, Kyoto (Japan). Faculty of Engineering

1998-05-22

Antimutagenic effect of humic substances has been reported by various investigators. In this research, the diminishing effect of DNA damaging toxicity by humic acid was evaluated for the influent and effluent of activated sludge tank receiving municipal wastewater and several DNA damaging chemicals (e.g., pyrene, 1-aminopyrene and benzo(a)pyrene) using Bacillus subtilis rec-assay. The diminishing effect was not apparent for influent but observed in the effluent. Among the DNA damaging chemicals, the DNA toxicity was effectively suppressed by humic acid for pyrene and benzo(a)pyrene. However, the effect was relatively smaller for 1-aminopyrene. 19 refs., 6 figs., 6 tabs.

Stabilization of microorganisms for in situ degradation of toxic chemicals

International Nuclear Information System (INIS)

Crawford, R.L.; Ralston, D.R.

1993-01-01

Methods for large-scale microencapsulation of bacteria and nutrients into microbeads with small enough diameters to travel through aquifers have been developed at the University of Idaho. Both free and immobilized cells of Flavobacterium ATCC 39723, a gram-negative aerobe that degrades various chlorinated phenols, into aquifer microcosms, through which pentachlorophenol (PCP)-contaminated groundwater flowed at in situ flow rates. Aquifer samples were collected with an auger from three wells at the University of Idaho Ground Water Research Site, and packed into 24 columns. Some sterile columns were also prepared, by irradiation at the Washington State University Radiation Center. In some of the columns the free Flavobacterium cells were mixed with the aquifer material before packing the columns. In others, agarose-microimmobilized Flavobacterium were mixed into the aquifer material. The effluent from each column was collected daily for 170 days and analyzed by UV spectroscopy or HPLC for remaining PCP. There were no statistically significant differences between the degradation rates of free or encapsulated Flavobacterium in sterile or native aquifer material as tested in these experiments. This work has shown at the lab scale that encapsulated PCP-degrading Flavobacterium were able to survive under conditions of starvation, predation, and lack of water

History and sensitivity comparison of the Spirodela polyrhiza microbiotest and Lemna toxicity tests

Directory of Open Access Journals (Sweden)

Baudo R.

2015-01-01

Full Text Available The history of toxicity tests with duckweeds shows that these assays with free-floating aquatic angiosperms are gaining increasing attention in ecotoxicological research and applications. Standard tests have been published by national and international organizations, mainly with the test species Lemna minor and Lemna gibba. Besides the former two test species the great duckweed Spirodela polyrhiza is to date also regularly used in duckweed testing. Under unfavorable environmental conditions, the latter species produces dormant stages (turions and this has triggered the attention of two research groups from Belgium and Greece to jointly develop a “stock culture independent” microbiotest with S. polyrhiza. A 72 h new test has been worked out which besides its independence of stock culturing and maintenance of live stocks is very simple and practical to perform, and much less demanding in space and time than the conventional duckweed tests. Extensive International Interlaboratory Comparisons on the S. polyrhiza microbiotest showed its robustness and reliability and triggered the decision to propose this new assay to the ISO for endorsement and publication as a standard toxicity test for duckweeds. Sensitivity comparison of the 72 h S. polyrhiza microbiotest with the 7d L. minor assay for 22 compounds belonging to different groups of chemicals revealed that based on growth as the effect criterion both duckweed assays have a similar sensitivity. Taking into account its multiple advantages and assets, the S. polyrhiza microbiotest is a reliable and attractive alternative to the conventional duckweed tests.

Metabolic enzyme microarray coupled with miniaturized cell-culture array technology for high-throughput toxicity screening.

Science.gov (United States)

Lee, Moo-Yeal; Dordick, Jonathan S; Clark, Douglas S

2010-01-01

Due to poor drug candidate safety profiles that are often identified late in the drug development process, the clinical progression of new chemical entities to pharmaceuticals remains hindered, thus resulting in the high cost of drug discovery. To accelerate the identification of safer drug candidates and improve the clinical progression of drug candidates to pharmaceuticals, it is important to develop high-throughput tools that can provide early-stage predictive toxicology data. In particular, in vitro cell-based systems that can accurately mimic the human in vivo response and predict the impact of drug candidates on human toxicology are needed to accelerate the assessment of drug candidate toxicity and human metabolism earlier in the drug development process. The in vitro techniques that provide a high degree of human toxicity prediction will be perhaps more important in cosmetic and chemical industries in Europe, as animal toxicity testing is being phased out entirely in the immediate future.We have developed a metabolic enzyme microarray (the Metabolizing Enzyme Toxicology Assay Chip, or MetaChip) and a miniaturized three-dimensional (3D) cell-culture array (the Data Analysis Toxicology Assay Chip, or DataChip) for high-throughput toxicity screening of target compounds and their metabolic enzyme-generated products. The human or rat MetaChip contains an array of encapsulated metabolic enzymes that is designed to emulate the metabolic reactions in the human or rat liver. The human or rat DataChip contains an array of 3D human or rat cells encapsulated in alginate gels for cell-based toxicity screening. By combining the DataChip with the complementary MetaChip, in vitro toxicity results are obtained that correlate well with in vivo rat data.

Rapid multiple immunoenzyme assay of mycotoxins.

Science.gov (United States)

Urusov, Alexandr E; Zherdev, Anatoly V; Petrakova, Alina V; Sadykhov, Elchin G; Koroleva, Olga V; Dzantiev, Boris B

2015-01-27

Mycotoxins are low molecular weight fungal metabolites that pose a threat as toxic contaminants of food products, thereby necessitating their effective monitoring and control. Microplate ELISA can be used for this purpose, but this method is characteristically time consuming, with a duration extending to several hours. This report proposes a variant of the ELISA method for the detection and quantification of three mycotoxins, ochratoxin A, aflatoxin B1 and zearalenone, in the kinetic regime. The main requirement for the proposed kinetic protocol was to provide a rapid method that combined sensitivity and accuracy. The use of biotin with an extended spacer together with a streptavidin-polyperoxidase conjugate provided high signal levels, despite these interactions occurring under non-equilibrium conditions. Duration of the individual mycotoxin assays was 20 min, whereas the analysis of all three mycotoxins in parallel reached a maximum duration of 25 min. Recovery of at least 95% mycotoxins in water-organic extracts was shown. The developed assays were successfully validated using poultry processing products and corn samples spiked with known quantities of mycotoxins. The detection limits for aflatoxin B1, ochratoxin A and zearalenone in these substances were 0.24, 1.2 and 3 ng/g, respectively.

Clinical and Functional Assays of Radiosensitivity and Radiation-Induced Second Cancer

Directory of Open Access Journals (Sweden)

Mohammad Habash

2017-10-01

Full Text Available Whilst the near instantaneous physical interaction of radiation energy with living cells leaves little opportunity for inter-individual variation in the initial yield of DNA damage, all the downstream processes in how damage is recognized, repaired or resolved and therefore the ultimate fate of cells can vary across the population. In the clinic, this variability is observed most readily as rare extreme sensitivity to radiotherapy with acute and late tissue toxic reactions. Though some radiosensitivity can be anticipated in individuals with known genetic predispositions manifest through recognizable phenotypes and clinical presentations, others exhibit unexpected radiosensitivity which nevertheless has an underlying genetic cause. Currently, functional assays for cellular radiosensitivity represent a strategy to identify patients with potential radiosensitivity before radiotherapy begins, without needing to discover or evaluate the impact of the precise genetic determinants. Yet, some of the genes responsible for extreme radiosensitivity would also be expected to confer susceptibility to radiation-induced cancer, which can be considered another late adverse event associated with radiotherapy. Here, the utility of functional assays of radiosensitivity for identifying individuals susceptible to radiotherapy-induced second cancer is discussed, considering both the common mechanisms and important differences between stochastic radiation carcinogenesis and the range of deterministic acute and late toxic effects of radiotherapy.

Soil-based screening for iron toxicity tolerance in rice using pots

Directory of Open Access Journals (Sweden)

Mouritala Sikirou

2016-10-01

Full Text Available The objective of this study was to assess the reliability of pot-based screening method for iron (Fe toxicity tolerance in rice using soils from hot spots. Five lowland rice varieties with known reaction to Fe toxicity were grown in pots in a screen house for three seasons. Fe-toxic soils from two hot spot fields – Edozighi, Nigeria and Niaouli, Benin were used and soil from Africa Rice Center (AfricaRice experimental farm, Cotonou, Benin was included as control. Leaf bronzing score (LBS was determined at different stages, and grain yield was determined at maturity. Heritability was estimated using data across the three seasons. High heritability was recorded for LBS and grain yield. Grain yield reduction in stress treatment relative to control varied from 15 to 56% depending on the variety and soil. Bao Thai, Suakoko 8, and WITA 4 had better performance under Fe toxicity in terms of LBS, yield and relative yield reduction, whereas Bouake 189 and IR64 had poorer performance. Grain yield and LBS were significantly correlated but negatively at 60 days after sowing (DAS. Overall, the results found in this experiment were consistent with previous field studies. Therefore, pot screening using soils from hot spots can be used by rice breeding programs to reliably assess Fe toxicity tolerance ex situ.

Human neuronal cell based assay: A new in vitro model for toxicity evaluation of ciguatoxin.

Science.gov (United States)

Coccini, Teresa; Caloni, Francesca; De Simone, Uliana

2017-06-01

Ciguatoxins (CTXs) are emerging marine neurotoxins representing the main cause of ciguatera fish poisoning, an intoxication syndrome which configures a health emergency and constitutes an evolving issue constantly changing due to new vectors and derivatives of CTXs, as well as their presence in new non-endemic areas. The study applied the neuroblastoma cell model of human origin (SH-SY5Y) to evaluate species-specific mechanistic information on CTX toxicity. Metabolic functionality, cell morphology, cytosolic Ca 2+ i responses, neuronal cell growth and proliferation were assessed after short- (4-24h) and long-term exposure (10days) to P-CTX-3C. In SH-SY5Y, P-CTX-3C displayed a powerful cytotoxicity requiring the presence of both Veratridine and Ouabain. SH-SY5Y were very sensitive to Ouabain: 10 and 0.25nM appeared the optimal concentrations, for short- and long-term toxicity studies, respectively, to be used in co-incubation with Veratridine (25μM), simulating the physiological and pathological endogenous Ouabain levels in humans. P-CTX-3C cytotoxic effect, on human neurons co-incubated with OV (Ouabain+Veratridine) mix, was expressed starting from 100pM after short- and 25pM after long-term exposure. Notably, P-CTX-3C alone at 25nM induced cytotoxicity after 24h and prolonged exposure. This human brain-derived cell line appears a suitable cell-based-model to evaluate cytotoxicity of CTX present in marine food contaminated at low toxic levels and to characterize the toxicological profile of other/new congeners. Copyright © 2017 Elsevier B.V. All rights reserved.

Involvement of the histamine H{sub 4} receptor in clozapine-induced hematopoietic toxicity: Vulnerability under granulocytic differentiation of HL-60 cells

Energy Technology Data Exchange (ETDEWEB)

Goto, Aya; Mouri, Akihiro; Nagai, Tomoko; Yoshimi, Akira; Ukigai, Mako; Tsubai, Tomomi; Hida, Hirotake [Division of Clinical Sciences and Neuropsychopharmacology, Faculty and Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503 (Japan); Ozaki, Norio [Department of Psychiatry, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550 (Japan); Noda, Yukihiro, E-mail: ynoda@meijo-u.ac.jp [Division of Clinical Sciences and Neuropsychopharmacology, Faculty and Graduate School of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503 (Japan)

2016-09-01

Clozapine is an effective antipsychotic for treatment-resistant schizophrenia, but can cause fatal hematopoietic toxicity as agranulocytosis. To elucidate the mechanism of hematopoietic toxicity induced by clozapine, we developed an in vitro assay system using HL-60 cells, and investigated the effect on hematopoiesis. HL-60 cells were differentiated by all-trans retinoic acid (ATRA) into three states according to the following hematopoietic process: undifferentiated HL-60 cells, those undergoing granulocytic ATRA-differentiation, and ATRA-differentiated granulocytic cells. Hematopoietic toxicity was evaluated by analyzing cell survival, cell proliferation, granulocytic differentiation, apoptosis, and necrosis. In undifferentiated HL-60 cells and ATRA-differentiated granulocytic cells, both clozapine (50 and 100 μM) and doxorubicin (0.2 µM) decreased the cell survival rate, but olanzapine (1–100 µM) did not. Under granulocytic differentiation for 5 days, clozapine, even at a concentration of 25 μM, decreased survival without affecting granulocytic differentiation, increased caspase activity, and caused apoptosis rather than necrosis. Histamine H{sub 4} receptor mRNA was expressed in HL-60 cells, whereas the expression decreased under granulocytic ATRA-differentiation little by little. Both thioperamide, a histamine H{sub 4} receptor antagonist, and DEVD-FMK, a caspase-3 inhibitor, exerted protection against clozapine-induced survival rate reduction, but not of live cell counts. 4-Methylhistamine, a histamine H{sub 4} receptor agonist, decreased the survival rate and live cell counts, as did clozapine. HL-60 cells under granulocytic differentiation are vulnerable under in vitro assay conditions to hematopoietic toxicity induced by clozapine. Histamine H{sub 4} receptor is involved in the development of clozapine-induced hematopoietic toxicity through apoptosis, and may be a potential target for preventing its occurrence through granulocytic differentiation

Field instruments for real time in-situ crude oil concentration measurements

International Nuclear Information System (INIS)

Fuller, C.B.; Bonner, J.S.; Page, C.A.; Arrambide, G.; Sterling, M.C.Jr.; Ojo, T.O.

2003-01-01

Accidental oil spills, contaminant release during resuspension, storms, and harmful algal blooms are all episodic events that can effect coastal margins. It is important to quantitatively describe water and ecological quality evolution and predict the impact to these areas by such events, but traditional sampling methods miss environmental activity during cyclical events. This paper presents a new sampling approach that involves continuous, real-time in-situ monitoring to provide data for development of comprehensive modeling protocols. It gives spill response coordinators greater assurance in making decisions using the latest visualization tools which are based on a good understanding of the physical processes at work in pulsed events. Five sensors for rapid monitoring of crude oil concentrations in aquatic systems were described. The in-situ and ex-situ sensors can measure plume transport and estimate polycyclic aromatic hydrocarbon exposure concentrations to assess risk of toxicity. A brief description and evaluation of the following 5 sensors was provided: the LISST-100 by Sequoia Instrument, a submersible multi-angle laser scattering instrument; the AU-10 field fluorometer by Turner Designs, an ex-situ single wavelength fluorometer; the Flashlamp by WET Labs Inc., an in-situ single wavelength fluorometer; and, the ECO-FL3 and SAFire by WET Labs Inc., two in-situ multiple wavelength fluorometers. These instruments were used to analyze crude oil emissions of various concentrations. All of the instruments followed a linear response within the tested concentration range. At the lowest concentrations the LISST-100 was not as effective as the fluorometers because of limited particle volume for scatter. For the AU-10 field fluorometer, the highest concentrations tested were above the measurement range of the instrument. 6 refs., 5 figs

Study of serum TSH content in functioning thyroid gland adenoma by 'supersensitive' immunoradiometric assay

International Nuclear Information System (INIS)

Foeldes, Janos; Banos, Csaba; Csillag, Jozsef; Lakatos, Peter; Tarjan, Gabor; 2546970HU)

1987-01-01

Determinations of serum TSH levels by immunoradiometric assay (IRMA)-math TSH (Mallinckrodt) kit and of the thyroid function by scintiscanning using 99m Tc-pertechnetate (20-40 MBq) were carried out paralelly in euthyroid and hyperthyroid patients. A comparison of the two tests allowed a better distinction of preclinical hyperthyreosis from toxic adenomas. (L.E.)

Study on a new calibration methods of in-situ HPGe γ spectrometers used for non-destructive analyzing radioactivity in nuclear facilities decommissioning

International Nuclear Information System (INIS)

Xiao Xuefu; Song Lijun; Wang Yulai; Wen Fuping; Liao Haitao; Ban Ying; Xia Yihua; Li Ruixiang; Li Hang; Tu Xingmin

2007-06-01

A new calibration technique, which is the Monte Carlo modeling technique, of in-situ HPGe γ spectrometers used for non-destructive analyzing radioactivity in nuclear facilities decommissioning, is presented. A series of assay for some stainless steel pipes and tanks in some nuclear facilities/laboratories of CIAE are taken on site with the in-situ HPGe γ spectrometer. At the same time, some examples are taken and analyzed in laboratories. The relative bias/variation between the values of activity measured by in-situ HPGe γ spectrometers on site and that analyzed in laboratory is less than ±45.0%. (authors)

Drug-mediated toxicity: illuminating the 'bad' in the test tube by means of cellular assays?

Science.gov (United States)

Tralau, Tewes; Luch, Andreas

2012-07-01

Health problems are rising worldwide, be it as a consequence of lifestyle and longevity in increasingly affluent societies or due to a sharp rise in bacterial antibiotic resistance. The pharmaceutical industry is caught between high rates of attrition and the rather slow pace of a historically large regulatory system for pharmacological safety. Meanwhile, the past decade has seen a tremendous evolution of the biological toolbox, most notably of cellular assays, stem-cell differentiation and organ-mimicking systems. These systems were readily adapted for lead-compound identification. However, their use as toxicological test systems is lagging behind, not least because of a lack of regulatory acceptance. This review tries to elucidate the scale of the problem and discusses the applicability of the assays currently available, with particular regard to the use of stem cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

Novel Strategies for the Removal of Toxic Metals from Soils and Waters

Science.gov (United States)

Roundhill, D. Max

2004-02-01

This article surveys the toxicities of mercury, cadmium, lead, copper, cadmium, and the actinides. Strategies for the removal of these metals include surfactants, aqueous biphasic systems, and liquid membranes. For soils, both in situ stabilization and detection are discussed. For extraction from soils, electrokinetic extraction, phytoremediation, and bioremediation methods are critically evaluated. This article provides an educator with the resources to set up a series of lectures on inorganic aspects of environmental chemistry.

Evaluation of acute and chronic toxicity of DSS and LAS surfactants undergoing the irradiation with electron beam

International Nuclear Information System (INIS)

Romanelli, Maria Fernanda

2004-01-01

Surfactants are synthetic organic compounds widely used in cosmetic, food, textile, dyers and paper production industries and in particular detergents and others cleaning products industries. The world consumption is nearly 8 million tons per year. One of the main environmental issues coming from the use of these compounds is their toxicity that compromises the biological treatment of effluents and the quality of receiving waters. The objective of this work was the application of ionizing radiation by electron beam in the degradation and reduction of acute and chronic toxicities of surfactants sodium dodecylsulfate (SDS), dodecyl p-benzenesulfonate acid (LAS) and sodium dodecyl p-benzenesulfonate (LAS). This treatment technology has been studied as a pre-treatment for effluents containing toxic and non-biodegradable compounds, before the biological treatment. Two acute toxicity assays were employed, one with the micro-crustacean Daphnia similis and the other with the luminescent bacterium Vibrio fischeri along with a chronic toxicity assay with the micro-crustacean Ceriodaphnia dubia (just for SDS and acid LAS) for the non-irradiated and irradiated samples and radiation doses 3.0 kGy, 6.0 kGy, 9.0 kGy and 12.0 kGy. Physical-chemical parameters were evaluated for the following up the degradation of the surfactant molecules. The reductions of acute toxicity varied between 72.49% and 90.98% for SDS, 18.22% and 78.98% for acid LAS and 82.66% and 94.26% for sodium LAS. For the chronic toxicity, the reduction percentages varied between 64.03% and 83.01% for SDS and 47.48% and 64.91% for acid LAS. When one considers the application of the electron beam as a pre-treatment of effluents containing high concentrations of surfactants, the toxicity is an essential parameter allowing the further biological treatment of these effluents. (author)

Decolorization of different textile dyes by Penicillium simplicissimum and toxicity evaluation after fungal treatment

Directory of Open Access Journals (Sweden)

L.R. Bergsten-Torralba

2009-12-01

Full Text Available The objective of this study was to investigate the capacity of decolorization and detoxification of the textile dyes Reactive Red 198 (RR198, Reactive Blue 214 (RB214, Reactive Blue 21 (RB21 and the mixture of the three dyes (MXD by Penicillium simplicissimum INCQS 40211. The dye RB21, a phthalocyanine, was totally decolorized in 2 days, and the others, the monoazo RR198, the diazo RB214 and MXD were decolorized after 7 days by P. simplicissimum. Initially the dye decolorization involved dye adsorption by the biomass followed by degradation. The acute toxicity after fungal treatment was monitored with the microcrustacean Daphnia pulex and measured through Effective Concentration 50% (EC50. P. simplicissimum reduced efficiently the toxicity of RB21 from moderately acutely toxic to minor acutely toxic and it also reduced the toxicity of RB214 and MXD, which remained minor acutely toxic. Nevertheless, the fungus increased the toxicity of RR198 despite of the reduction of MXD toxicity, which included this dye. Thus, P. simplicissimum INCQS 40211 was efficient to decolorize different textile dyes and the mixture of them with a significant reduction of their toxicity. In addition this investigation also demonstrated the need of toxicological assays associated to decolorization experiments.

Inhibition of autophagy contributes to the toxicity of cadmium telluride quantum dots in Saccharomyces cerevisiae

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Fan J

2016-07-01

Full Text Available Junpeng Fan,1–4 Ming Shao,1–4 Lu Lai,3–5 Yi Liu,3–5 Zhixiong Xie1–4,6 1College of Life Sciences, Wuhan University, 2Hubei Provincial Cooperative Innovation Center of Industrial Fermentation,3State Key Laboratory of Virology, 4Key Laboratory of Analytical Chemistry for Biology and Medicine (MOE, 5College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 6School of Life Science and Technology, Hubei Engineering University, Xiaogan, People’s Republic of China Abstract: Cadmium telluride quantum dots (CdTe QDs are used as near-infrared probes in biologic and medical applications, but their cytological effects and mechanism of potential toxicity are still unclear. In this study, we evaluated the toxicity of CdTe QDs of different sizes and investigated their mechanism of toxicity in the yeast Saccharomyces cerevisiae. A growth inhibition assay revealed that orange-emitting CdTe (O-CdTe QDs (half inhibitory concentration [IC50] =59.44±12.02 nmol/L were more toxic than green-emitting CdTe QDs (IC50 =186.61±19.74 nmol/L to S. cerevisiae. Further studies on toxicity mechanisms using a transmission electron microscope and green fluorescent protein tagged Atg8 processing assay revealed that O-CdTe QDs could partially inhibit autophagy at a late stage, which differs from the results reported in mammalian cells. Moreover, autophagy inhibited at a late stage by O-CdTe QDs could be partially recovered by enhancing autophagy with rapamycin (an autophagy activator, combined with an increased number of living cells. These results indicate that inhibition of autophagy acts as a toxicity mechanism of CdTe QDs in S. cerevisiae. This work reports a novel toxicity mechanism of CdTe QDs in yeast and provides valuable information on the effect of CdTe QDs on the processes of living cells. Keywords: CdTe quantum dots, Saccharomyces cerevisiae, toxicity, autophagy

Integration of electrochemistry in micro-total analysis systems for biochemical assays: recent developments.

Science.gov (United States)

Xu, Xiaoli; Zhang, Song; Chen, Hui; Kong, Jilie

2009-11-15

Micro-total analysis systems (microTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of microTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.

ZyFISH: a simple, rapid and reliable zygosity assay for transgenic mice.

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Donal McHugh

Full Text Available Microinjection of DNA constructs into fertilized mouse oocytes typically results in random transgene integration at a single genomic locus. The resulting transgenic founders can be used to establish hemizygous transgenic mouse lines. However, practical and experimental reasons often require that such lines be bred to homozygosity. Transgene zygosity can be determined by progeny testing assays which are expensive and time-consuming, by quantitative Southern blotting which is labor-intensive, or by quantitative PCR (qPCR which requires transgene-specific design. Here, we describe a zygosity assessment procedure based on fluorescent in situ hybridization (zyFISH. The zyFISH protocol entails the detection of transgenic loci by FISH and the concomitant assignment of homozygosity using a concise and unbiased scoring system. The method requires small volumes of blood, is scalable to at least 40 determinations per assay, and produces results entirely consistent with the progeny testing assay. This combination of reliability, simplicity and cost-effectiveness makes zyFISH a method of choice for transgenic mouse zygosity determinations.

Reproductive toxicity assessment of surface water of the Tai section of the Yangtze River, China by in vitro bioassays coupled with chemical analysis

International Nuclear Information System (INIS)

Wang Xiaoyi; Wu Jiang; Hao Yingqun; Zhu Bingqing; Shi Wei; Hu Guanjiu; Han Xiaodong; Giesy, John P.; Yu Hongxia

2011-01-01

Reproductive toxicity of organic extracts of the surface water from the Tai section of the Yangtze River was assessed by in vitro cytotoxity assays and selected persistent organic pollutants including PCBs, OCPs and PAHs were quantified by instrumental analysis. Eleven of the US EPA priority PAHs were detected. Individual PAHs were found to range from 0.7 to 20 ng/L. Concentrations of BaP did not exceed the national drinking water source quality standard of China. However, a 286-fold concentrated organic extract induced significant reproductive toxicity in adult male rats. The morphology of cells, MTT assay and LDH release assay were all affected by exposure to the organic extracts of water. The results of the reproductive toxicity indicated that PAHs posed the greatest risk of the chemicals studied. The compounds present in the water could be bioconcentrated and result in adverse effects. - Highlights: → Only 11 PAHs of US EPA priority PAHs were detected in surface water the Yangtze River. → Level of BaP didn't exceed national drinking water source quality standard of China. → 286-fold concentrated organic extracts induced great reproductive toxicity in rats. → PAHs posed the greatest risk of the chemicals studied. → The compounds in the water could be bioconcentrated and result in adverse effects. - In vitro bioassay responses observed in Yangtze River source water extracts showed great reproductive toxicity, and PAHs were responsible.

Toxicity testing of four silver nanoparticle-coated dental castings in 3-D LO2 cell cultures.

Science.gov (United States)

Zhao, Yi-Ying; Chu, Qiang; Shi, Xu-Er; Zheng, Xiao-Dong; Shen, Xiao-Ting; Zhang, Yan-Zhen

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical applications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.

Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

Energy Technology Data Exchange (ETDEWEB)

Joseph Bidwell; Jonathan Fisher; Naomi Cooper

2008-03-31

This study investigated potential biological effects of produced water contamination derived from occasional surface overflow and possible subsurface intrusion at an oil production site along the shore of Skiatook Lake, Oklahoma. We monitored basic chemistry and acute toxicity to a suite of standard aquatic test species (fathead minnow-Pimephales promelas, Daphnia pulex, Daphnia magna, and Ceriodaphnia dubia) in produced water and in samples taken from shallow groundwater wells on the site. Toxicity identification evaluations and ion toxicity modeling were used to identify toxic constituents in the samples. Lake sediment at the oil production site and at a reference site were also analyzed for brine intrusion chemically and by testing sediment toxicity using the benthic invertebrates, Chironomus dilutus, and Hyallela azteca. Sediment quality was also assessed with in situ survival and growth studies with H. azteca and the Asian clam, Corbicula fluminea, and by benthic macroinvertebrate community sampling. The produced water was acutely toxic to the aquatic test organisms at concentrations ranging from 1% to 10% of the whole produced water sample. Toxicity identification evaluation and ion toxicity modeling indicated major ion salts and hydrocarbons were the primary mixture toxicants. The standardized test species used in the laboratory bioassays exhibited differences in sensitivity to these two general classes of contaminants, which underscores the importance of using multiple species when evaluating produced water toxicity. Toxicity of groundwater was greater in samples from wells near a produced water injection well and an evaporation pond. Principle component analyses (PCA) of chemical data derived from the groundwater wells indicated dilution by lake water and possible biogeochemical reactions as factors that ameliorated groundwater toxicity. Elevated concentrations of major ions were found in pore water from lake sediments, but toxicity from these ions was

ToxCast Profiling in a Human Stem Cell Assay for Developmental Toxicity (CompTox CoP)

Science.gov (United States)

Standard practice for assessing disruptions in embryogenesis involves testing pregnant animals of two species, typically rats and rabbits, exposed during major organogenesis and evaluated just prior to term. Under this design the major manifestations of developmental toxicity are...

Removal of antibiotics in wastewater by enzymatic treatment with fungal laccase - Degradation of compounds does not always eliminate toxicity.

Science.gov (United States)

Becker, Dennis; Varela Della Giustina, Saulo; Rodriguez-Mozaz, Sara; Schoevaart, Rob; Barceló, Damià; de Cazes, Matthias; Belleville, Marie-Pierre; Sanchez-Marcano, José; de Gunzburg, Jean; Couillerot, Olivier; Völker, Johannes; Oehlmann, Jörg; Wagner, Martin

2016-11-01

In this study, the performance of immobilised laccase (Trametes versicolor) was investigated in combination with the mediator syringaldehyde (SYR) in removing a mixture of 38 antibiotics in an enzymatic membrane reactor (EMR). Antibiotics were spiked in osmosed water at concentrations of 10μg·L(-1) each. Laccase without mediator did not reduce the load of antibiotics significantly. The addition of SYR enhanced the removal: out of the 38 antibiotics, 32 were degraded by >50% after 24h. In addition to chemical analysis, the samples' toxicity was evaluated in two bioassays (a growth inhibition assay and the Microtox assay). Here, the addition of SYR resulted in a time-dependent increase of toxicity in both bioassays. In cooperation with SYR, laccase effectively removes a broad range of antibiotics. However, this enhanced degradation induces unspecific toxicity. If this issue is resolved, enzymatic treatment may be a valuable addition to existing water treatment technologies. Copyright © 2016 Elsevier Ltd. All rights reserved.

An Exploratory Analysis of Stream Teratogenicity and Human Health Using Zebrafish Whole-Sediment Toxicity Test

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Matthew Dellinger

2014-02-01

Full Text Available This study demonstrates a novel application of effect-based toxicity testing for streams that may provide indications of co-perturbation to ecological and human health. For this study, a sediment contact assay using zebrafish (Danio rerio embryos was adapted to serve as an indicator of teratogenic stress within river sediments. Sediment samples were collected from Lake Michigan tributary watersheds. Sediment contact assay responses were then compared to prevalence of congenital heart disease (CHD and vital statistic birth indicators aggregated from civil divisions associated with the watersheds. Significant risk relationships were detected between variation in early life-stage (ELS endpoints of zebrafish embryos 72 h post-fertilization and the birth prevalence of human congenital heart disease, low birthweight and infant mortality. Examination of principal components of ELS endpoints suggests that variance related to embryo heart and circulatory malformations is most closely associated with human CHD prevalence. Though toxicity assays are sometimes used prospectively, this form of investigation can only be conducted retrospectively. These results support the hypothesis that bioassays normally used for ecological screening can be useful as indicators of environmental stress to humans and expand our understanding of environmental–human health linkages.

Chitinolitic activity in proteic extracts of Bacillus thuringiensis toxic to boll weevil (Anthonomus grandis)

Energy Technology Data Exchange (ETDEWEB)

Silva, T.S; Rocha, T.L. [EMBRAPA Recursos Geneticos e Biotecnologia, DF (Brazil); Vasconcelos, E.A.R [Universidade de Brasilia (UnB), DF (Brazil); Grossi-de-Sa, M.F. [Universidade Catolica de Brasilia, DF (Brazil)

2008-07-01

Full text: Bacillus thuringiensis (Bt) is a spore forming bacteria, which produces Cry proteins toxic towards several insect orders. Bt S 811 strain produces at least three Cry toxins: Cry1Ab, Cry1Ia12, and Cry8, and shown toxicity to insects from Coleoptera order. In order to characterize the production of theses toxins, and check its activity against Boll weevil larvae, proteic extracts from Bt cells and supernatant proteins from the bacterial culture, were obtained at different stages of cell cycle; 8, 16, 24, and 32 hours after inoculation (HAI). Proteins from 32 HAI of the supernatant, and 8 HAI of the cellular fractions, shown highest activity towards the Boll weevil larvae. Western blotting assays using anti-Cry8 and anti-Cry1I were carried out to analyse these toxins in the Bt proteic extracts. The existence of a Cry8 was detected at 8 HAI in the cellular fraction, what allow associate this molecule with the toxicity of this fraction. However, toxicity observed at 32 HAI in the supernatant fraction, was not possible to be associated with Cry8 or Cry1Ia toxins, indicating that there are another protein(s) responsible for the toxicity. A protein homo log to Cry1Ab was identified by 'Peptide Mass Fingerprint' at 32 HAI of the supernatant fraction and a chitin binding protein was identified by 2DE/MS/MS in this same stage and chitinolitic activity was also observed by enzymatic assay. All our data suggest a possible synergism between Cry toxins and a chitinase in the activity of this strain towards Boll weevil.

[The toxicity variation of organic extracts in drinking water treatment processes].

Science.gov (United States)

Mei, M; Wei, S; Zijian, W; Wenhua, W; Baohua, Z; Suxia, Z

2001-01-01

Source water samples and outlet water samples from different treatment processes of the Beijing Ninth Water Works were concentrated in situ with XAD-2 filled columns. GC-MS analysis and toxic assessment including acute toxicity evaluation by luminescent bacterium bioassay(Q67 strains) and mutagenicity assessment by Ames test(TA98 and TA100 strains with and without S9 addition) were conducted on these samples. The results showed that prechlorination caused the direct and indirect frame shift mutagenicity as well as indirect base pair substitute mutagenicity. Addition of coagulant may increase the base pair substitute mutagenic effects greatly. Sand and coal filtration and granular activated carbon filtration could effectively remove most of the formed mutagens. The rechlorination do not obviously increase the mutagenic effects. No mutagenic effect was observed in tap water. Acute toxicity showed the same variation with that of mutagenicity during the treatment processes. Sample from flocculation treatment process was found to be the most toxic sample. Results of GC-MS analysis showed that water in this plant was not contaminated by PCB. Concentrations of toluene, naphthalene and phenol increased in flocculation treatment process and in tap water. However, the concentrations of these substances were at the level of microgram/L, therefore, were not high enough to cause mutagenicity.

Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

International Nuclear Information System (INIS)

Tanner, Scott D.; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I.

2007-01-01

Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration

Multiplex bio-assay with inductively coupled plasma mass spectrometry: Towards a massively multivariate single-cell technology

Energy Technology Data Exchange (ETDEWEB)

Tanner, Scott D. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)], E-mail: sd.tanner@utoronto.ca; Ornatsky, Olga; Bandura, Dmitry R.; Baranov, Vladimir I. [Institute of Biomaterials and Biomedical Engineering, University of Toronto, Room 407, 164 College Street, Toronto, Ontario, M5S 3G9 (Canada)

2007-03-15

Recent progress in the development of massively multiplexed bioanalytical assays using element tags with inductively coupled plasma mass spectrometry detection is reviewed. Feasibility results using commercially available secondary immunolabeling reagents for leukemic cell lines are presented. Multiplex analysis of higher order is shown with first generation tag reagents based on functionalized carriers that bind lanthanide ions. DNA quantification using metallointercalation allows for cell enumeration or mitotic state differentiation. In situ hybridization permits the determination of cellular RNA. The results provide a feasibility basis for the development of a multivariate assay tool for individual cell analysis based on inductively coupled plasma mass spectrometry in a cytometer configuration.

Field sampling of soil pore water to evaluate trace element mobility and associated environmental risk

Energy Technology Data Exchange (ETDEWEB)

Moreno-Jimenez, Eduardo, E-mail: eduardo.moreno@uam.es [Departamento de Quimica Agricola, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Beesley, Luke [James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH (United Kingdom); Lepp, Nicholas W. [35, Victoria Road, Formby, Liverpool L37 7DH (United Kingdom); Dickinson, Nicholas M. [Department of Ecology, Lincoln University, Lincoln 7647, PO Box 84 (New Zealand); Hartley, William [School of Computing, Science and Engineering, University of Salford, Cockcroft Building, Salford, M5 4WT (United Kingdom); Clemente, Rafael [Dep. of Soil and Water Conservation and Organic Waste Management, CEBAS-CSIC, Campus Universitario de Espinardo, PO Box 164, 30100 Espinardo, Murcia (Spain)

2011-10-15

Monitoring soil pollution is a key aspect in sustainable management of contaminated land but there is often debate over what should be monitored to assess ecological risk. Soil pore water, containing the most labile pollutant fraction in soils, can be easily collected in situ offering a routine way to monitor this risk. We present a compilation of data on concentration of trace elements (As, Cd, Cu, Pb, and Zn) in soil pore water collected in field conditions from a range of polluted and non-polluted soils in Spain and the UK during single and repeated monitoring, and propose a simple eco-toxicity test using this media. Sufficient pore water could be extracted for analysis both under semi-arid and temperate conditions, and eco-toxicity comparisons could be effectively made between polluted and non-polluted soils. We propose that in-situ pore water extraction could enhance the realism of risk assessment at some contaminated sites. - Highlights: > In situ pore water sampling successfully evaluates trace elements mobility in soils. > Field sampling proved robust for different soils, sites and climatic regimes. > Measurements may be directly related to ecotoxicological assays. > Both short and long-term monitoring of polluted lands may be achieved. > This method complements other widely used assays for environmental risk assessment. - In situ pore water sampling from a wide variety of soils proves to be a beneficial application to monitor the stability of pollutants in soils and subsequent risk through mobility.

In situ vitrification of buried waste sites

International Nuclear Information System (INIS)

Shade, J.W.; Thompson, L.E.; Kindle, C.H.

1991-04-01

In situ vitrification (ISV) is a remedial technology initially developed to treat soils contaminated with a variety of organics, heavy metals, and/or radioactive materials. Recent tests have indicated the feasibility of applying the process to buried wastes including containers, combustibles, and buried metals. In addition, ISV is being considered for application to the emplacement of barriers and to the vitrification of underground tanks. This report provides a review of some of the recent experiences of applying ISV in engineering-scale and pilot-scale tests to wastes containing organics, the Environmental Protection Agency (EPA) Toxic metals buried in sealed containers, and buried ferrous metals, with emphasis on the characteristics of the vitrified product and adjacent soil. 9 refs., 2 figs., 3 tabs

High throughput comet assay to study genotoxicity of nanomaterials

Directory of Open Access Journals (Sweden)

Naouale El Yamani

2015-06-01

Full Text Available The unique physicochemical properties of engineered nanomaterials (NMs have accelerated their use in diverse industrial and domestic products. Although their presence in consumer products represents a major concern for public health safety, their potential impact on human health is poorly understood. There is therefore an urgent need to clarify the toxic effects of NMs and to elucidate the mechanisms involved. In view of the large number of NMs currently being used, high throughput (HTP screening technologies are clearly needed for efficient assessment of toxicity. The comet assay is the most used method in nanogenotoxicity studies and has great potential for increasing throughput as it is fast, versatile and robust; simple technical modifications of the assay make it possible to test many compounds (NMs in a single experiment. The standard gel of 70-100 μL contains thousands of cells, of which only a tiny fraction are actually scored. Reducing the gel to a volume of 5 μL, with just a few hundred cells, allows twelve gels to be set on a standard slide, or 96 as a standard 8x12 array. For the 12 gel format, standard slides precoated with agarose are placed on a metal template and gels are set on the positions marked on the template. The HTP comet assay, incorporating digestion of DNA with formamidopyrimidine DNA glycosylase (FPG to detect oxidised purines, has recently been applied to study the potential induction of genotoxicity by NMs via reactive oxygen. In the NanoTEST project we investigated the genotoxic potential of several well-characterized metal and polymeric nanoparticles with the comet assay. All in vitro studies were harmonized; i.e. NMs were from the same batch, and identical dispersion protocols, exposure time, concentration range, culture conditions, and time-courses were used. As a kidney model, Cos-1 fibroblast-like kidney cells were treated with different concentrations of iron oxide NMs, and cells embedded in minigels (12

A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

Science.gov (United States)

Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

2014-07-01

The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Oleuropein, a non-toxic olive iridoid, is an anti-tumor agent and cytoskeleton disruptor

International Nuclear Information System (INIS)

Hamdi, Hamdi K.; Castellon, Raquel

2005-01-01

Oleuropein, a non-toxic secoiridoid derived from the olive tree, is a powerful antioxidant and anti-angiogenic agent. Here, we show it to be a potent anti-cancer compound, directly disrupting actin filaments in cells and in a cell-free assay. Oleuropein inhibited the proliferation and migration of advanced-grade tumor cell lines in a dose-responsive manner. In a novel tube-disruption assay, Oleuropein irreversibly rounded cancer cells, preventing their replication, motility, and invasiveness; these effects were reversible in normal cells. When administered orally to mice that developed spontaneous tumors, Oleuropein completely regressed tumors in 9-12 days. When tumors were resected prior to complete regression, they lacked cohesiveness and had a crumbly consistency. No viable cells could be recovered from these tumors. These observations elevate Oleuropein from a non-toxic antioxidant into a potent anti-tumor agent with direct effects against tumor cells. Our data may also explain the cancer-protective effects of the olive-rich Mediterranean diet

Biocompatibility study of two diblock copolymeric nanoparticles for biomedical applications by in vitro toxicity testing

Energy Technology Data Exchange (ETDEWEB)

Goñi-de-Cerio, Felipe [GAIKER Technology Centre (Spain); Mariani, Valentina [European Commission, Nanobiosciences Unit, Institute for Health and Consumer Protection, Joint Research Centre (Italy); Cohen, Dror [Dead Sea Laboratories, AHAVA (Israel); Madi, Lea [Tel-Aviv University, Department of Physiology and Pharmacology, Sackler School of Medicine (Israel); Thevenot, Julie; Oliveira, Hugo [ENSCPB, Université de Bordeaux (France); Uboldi, Chiara; Giudetti, Guido; Coradeghini, Rosella [European Commission, Nanobiosciences Unit, Institute for Health and Consumer Protection, Joint Research Centre (Italy); Garanger, Elisabeth [ENSCPB, Université de Bordeaux (France); Rossi, François [European Commission, Nanobiosciences Unit, Institute for Health and Consumer Protection, Joint Research Centre (Italy); Portugal-Cohen, Meital; Oron, Miriam [Dead Sea Laboratories, AHAVA (Israel); Korenstein, Rafi [Tel-Aviv University, Department of Physiology and Pharmacology, Sackler School of Medicine (Israel); Lecommandoux, Sébastien [ENSCPB, Université de Bordeaux (France); Ponti, Jessica [European Commission, Nanobiosciences Unit, Institute for Health and Consumer Protection, Joint Research Centre (Italy); Suárez-Merino, Blanca; Heredia, Pedro, E-mail: heredia@gaiker.es [GAIKER Technology Centre (Spain)

2013-11-15

Drugs used for chemotherapy normally carry out adverse, undesired effects. Nanotechnology brings about new horizons to tackle cancer disease with a different strategy. One of the most promising approaches is the use of nanocarriers to transport active drugs. These nanocarriers need to have special properties to avoid immune responses and toxicity, and it is critical to study these effects. Nanocarriers may have different nature, but polypeptide-based copolymers have attracted considerable attention for their biocompatibility, controlled and slow biodegradability as well as low toxicity. Little has been done regarding specific nanocarriers toxicity. In this study, we performed a thorough toxicological study of two different block copolymer nanoparticles (NPs); poly(trimethylene carbonate)-block–poly(l-glutamic acid) (PTMC-b–PGA) and poly(ethylene glycol)-block–poly(γ-benzyl-l-glutamate) (PEG-b–PBLG) with sizes between 113 and 131 nm. Low blood–serum–protein interaction was observed. Moreover, general toxicity assays and other endpoints (apoptosis or necrosis) showed good biocompatibility for both NPs. Reactive oxygen species increased in only two cell lines (HepG2 and TK6) in the presence of PTMC-b–PGA. Cytokine production study showed cytokine induction only in one cell line (A549). We also performed the same assays on human skin organ culture before and after UVB light treatment, with a moderate toxicity after treatment independent of NPs presence or absence. Interleukin 1 induction was also observed due to the combined effect of PEG-b–PBLG and UVB light irradiation. Future in vivo studies for biocompatibility and toxicity will provide more valuable information, but, so far, the findings presented here suggest the possibility of using these two NPs as nanocarriers for nanomedical applications, always taking into account the application procedure and the way in which they are implemented.

A multi-endpoint, high-throughput study of nanomaterial toxicity in Caenorhabditis elegans

Science.gov (United States)

Jung, Sang-Kyu; Qu, Xiaolei; Aleman-Meza, Boanerges; Wang, Tianxiao; Riepe, Celeste; Liu, Zheng; Li, Qilin; Zhong, Weiwei

2015-01-01

The booming nanotech industry has raised public concerns about the environmental health and safety impact of engineered nanomaterials (ENMs). High-throughput assays are needed to obtain toxicity data for the rapidly increasing number of ENMs. Here we present a suite of high-throughput methods to study nanotoxicity in intact animals using Caenorhabditis elegans as a model. At the population level, our system measures food consumption of thousands of animals to evaluate population fitness. At the organism level, our automated system analyzes hundreds of individual animals for body length, locomotion speed, and lifespan. To demonstrate the utility of our system, we applied this technology to test the toxicity of 20 nanomaterials under four concentrations. Only fullerene nanoparticles (nC60), fullerol, TiO2, and CeO2 showed little or no toxicity. Various degrees of toxicity were detected from different forms of carbon nanotubes, graphene, carbon black, Ag, and fumed SiO2 nanoparticles. Aminofullerene and UV irradiated nC60 also showed small but significant toxicity. We further investigated the effects of nanomaterial size, shape, surface chemistry, and exposure conditions on toxicity. Our data are publicly available at the open-access nanotoxicity database www.QuantWorm.org/nano. PMID:25611253

Recommendations for safety testing with the in vivo comet assay.

Science.gov (United States)

Vasquez, Marie Z

2012-08-30

While the in vivo comet assay increases its role in regulatory safety testing, deliberations about the interpretation of comet data continue. Concerns can arise regarding comet assay publications with limited data from non-blind testing of positive control compounds and using protocols (e.g. dose concentrations, sample times, and tissues) known to give an expected effect. There may be a tendency towards bias when the validation or interpretation of comet assay data is based on results generated by widely accepted but non-validated assays. The greatest advantages of the comet assay are its sensitivity and its ability to detect genotoxicity in tissues and at sample times that could not previously be evaluated. Guidelines for its use and interpretation in safety testing should take these factors into account. Guidelines should be derived from objective review of data generated by blind testing of unknown compounds dosed at non-toxic concentrations and evaluated in a true safety-testing environment, where the experimental design and conclusions must be defensible. However, positive in vivo comet findings with such compounds are rarely submitted to regulatory agencies and this data is typically unavailable for publication due to its proprietary nature. To enhance the development of guidelines for safety testing with the comet assay, and with the permission of several sponsors, this paper presents and discusses relevant data from multiple GLP comet studies conducted blind, with unknown pharmaceuticals and consumer products. Based on these data and the lessons we have learned through the course of conducting these studies, I suggest significant adjustments to the current conventions, and I provide recommendations for interpreting in vivo comet assay results in situations where risk must be evaluated in the absence of carcinogenicity or clinical data. Copyright © 2012 Elsevier B.V. All rights reserved.

Development and validation of OECD test guidelines on mollusc reproductive toxicity tests

DEFF Research Database (Denmark)

Lagadic, Laurent; Holbech, Henrik; hutchinson, tom

the comparison of endpoints relevant for reproduction in invertebrates often shows a much higher sensitivity in molluscs vs. e.g. daphnids. The OECD test guideline programme has thus been extended to cover reproduction effects of chemicals in molluscs. Existing mollusc toxicity test protocols have been reviewed...... in an OECD Detailed Review Paper that identifies two relevant candidate species for developing freshwater tests: Potamopyrgus antipodarum and Lymnaea stagnalis. However, this review did not clarify which toxicity test design/conditions are the most appropriate for chemicals assessment. Therefore, a mollusc...... reproduction test guideline will be developed describing partial- and full- life-cycle test protocols in these species, so as to propose a balanced suite of apical mollusc toxicity tests applicable for the assessment of any type of chemical, including endocrine disruptors, as level 4 and 5 assays of the EDTA...

Resveratrol radiomodifier effect on Danio rerio embriolarval assay