The use of cryopreserved sea urchin embryos (Paracentrotus lividus) in marine quality assessment.

PubMed

Paredes, E; Bellas, J

2015-06-01

We have established for first time an ecotoxicological bioassay using cryopreserved sea urchin embryos (Paracentotus lividus) and provided a comparison to the already standardized sea urchin embryo-larval bioassay, using selected (organic and inorganic) pollutants and sediment elutriates from 4 different locations from Ria de Vigo harbour (Galicia, NW Iberian Peninsula). A cryopreservation protocol was designed in order to enable the successful cryopreservation and cryobanking of gametes and embryos to be used for marine quality assessment and ensure the accessibility to high quality reproductive material all year round, as an option to conditioning adults for out of season reproduction. The calculated EC50 using the cryopreserved blastula was 53.7 μg L(-1) for copper, 81.0 μg L(-1) for lead, 300.6 μg L(-1) for BP-3 and 300.6 μg L(-1) for 4-MBC. The sensitivity of the classic sea urchin embryo-larval bioassay was compared with the bioassay conducted with cryopreserved blastula. The results showed that the use of cryopreserved blastula bioassay allows detecting lower concentrations of pollutants in comparison with the classic bioassay. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

PubMed

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

2013-05-15

The potential toxicity of sediments from various ports was assessed by means of two different liquid-phase toxicity bioassays (acute and chronic) with embryos and eggs of sea urchin Paracentrotus lividus. Performances of embryos and eggs of P. lividus in these bioassays were compared for their interchangeable applicability in integrated sediment quality assessment. The obtained endpoints (percentages of normally developed plutei and fertilized eggs) were linked to physical and chemical properties of sediments and demonstrated dependence on sediment contamination. The endpoints in the two bioassays were strongly correlated and generally exhibited similar tendency throughout the samples. Therein, embryos demonstrated higher sensitivity to elutriate exposure, compared to eggs. It was concluded that these tests could be used interchangeably for testing toxicity of marine sediments. Preferential use of any of the bioassays can be determined by the discriminatory capacity of the test or vulnerability consideration of the test subject to the surrounding conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

Efficacy of long-lasting insecticidal nets in use in Macha, Zambia, against the local Anopheles arabiensis population.

PubMed

Norris, Laura C; Norris, Douglas E

2011-08-31

The mosquito Anopheles arabiensis is the primary vector of Plasmodium falciparum in Macha, Zambia. A major portion of Zambia's current malaria control programme relies on long-lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS) with insecticides. Currently, the efficacy of these measures against An. arabiensis in Macha is unknown, and previous data has shown that An. arabiensis has continued to feed on human hosts, despite high ITN coverage. It is possible that this could be due to either decreased efficacy of ITNs in used in Macha, or pyrethroid resistance in the vector. F1 offspring of field-collected adult An. arabiensis were tested for insecticide resistance, using CDC bottle bioassays and deltamethrin ITN susceptibility assays. The mosquitoes were characterized for the knock-down resistance (kdr) allele by PCR. LLINs that had been in use for two years in nearby villages were collected and tested for residual deltamethrin concentration and net quality, and were used in bioassays against susceptible colonized Anopheles gambiae s.s. Keele. Additionally, a survey on ITN use and care was conducted among LLIN owners. In the F1 An. arabiensis field population, low levels of resistance to DDT and deltamethrin-treated net material were detected by bioassay, although the knock-down resistance (kdr) allele not present in the population. ITN evaluations revealed high variability in residual deltamethrin concentration, quality of the nets, and mosquito mortality in bioassays. Mortality against An. gambiae s.s. in bioassays was correlated with residual deltamethrin concentration, which was dependent upon the number of washes each net had received. Proper LLIN care was a strong determinant of LLIN efficacy, indicating that education on the importance of LLIN use and care is key when distributing nets. As there is little insecticide resistance in the local vector population, degradation of LLINs most likely allowed for continued human feeding by An. arabiensis. Continued monitoring and assessment of both the vector population and the efficacy of LLINs in use is necessary in order to appropriately modify vector control operations and prevent the development of pyrethroid resistance.

Technical requirements for bioassay support services

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hickman, D.P.; Anderson, A.L.

1991-05-01

This document provides the technical basis for the Chem-Nuclear Geotech (Geotech) bioassay program. It includes information and details that can be used as a model in providing technical contents and requirements for bioassay laboratory support, either internally or in solicitations by Geotech to obtain subcontractor laboratory support. It provides a detailed summary and description of the types of bioassay samples to be expected in support of Geotech remedial projects for the US Department of Energy and the bioassay services and analytical requirements necessary to process such samples, including required limits of sensitivity. General responsibilities of the bioassay laboratory are alsomore » addressed, including quality assurance. Peripheral information of importance to the program is included in the appendices of this document. 7 tabs.« less

International standards for monoclonal antibodies to support pre- and post-marketing product consistency: Evaluation of a candidate international standard for the bioactivities of rituximab.

PubMed

Prior, Sandra; Hufton, Simon E; Fox, Bernard; Dougall, Thomas; Rigsby, Peter; Bristow, Adrian

2018-01-01

The intrinsic complexity and heterogeneity of therapeutic monoclonal antibodies is built into the biosimilarity paradigm where critical quality attributes are controlled in exhaustive comparability studies with the reference medicinal product. The long-term success of biosimilars will depend on reassuring healthcare professionals and patients of consistent product quality, safety and efficacy. With this aim, the World Health Organization has endorsed the need for public bioactivity standards for therapeutic monoclonal antibodies in support of current controls. We have developed a candidate international potency standard for rituximab that was evaluated in a multi-center collaborative study using participants' own qualified Fc-effector function and cell-based binding bioassays. Dose-response curve model parameters were shown to reflect similar behavior amongst rituximab preparations, albeit with some differences in potency. In the absence of a common reference standard, potency estimates were in poor agreement amongst laboratories, but the use of the candidate preparation significantly reduced this variability. Our results suggest that the candidate rituximab standard can support bioassay performance and improve data harmonization, which when implemented will promote consistency of rituximab products over their life-cycles. This data provides the first scientific evidence that a classical standardization exercise allowing traceability of bioassay data to an international standard is also applicable to rituximab. However, we submit that this new type of international standard needs to be used appropriately and its role not to be mistaken with that of the reference medicinal product.

Soil bioassays as tools for sludge compost quality assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Domene, Xavier, E-mail: x.domene@creaf.uab.es; Sola, Laura; Ramirez, Wilson

2011-03-15

Composting is a waste management technology that is becoming more widespread as a response to the increasing production of sewage sludge and the pressure for its reuse in soil. In this study, different bioassays (plant germination, earthworm survival, biomass and reproduction, and collembolan survival and reproduction) were assessed for their usefulness in the compost quality assessment. Compost samples, from two different composting plants, were taken along the composting process, which were characterized and submitted to bioassays (plant germination and collembolan and earthworm performance). Results from our study indicate that the noxious effects of some of the compost samples observed inmore » bioassays are related to the low organic matter stability of composts and the enhanced release of decomposition endproducts, with the exception of earthworms, which are favored. Plant germination and collembolan reproduction inhibition was generally associated with uncomposted sludge, while earthworm total biomass and reproduction were enhanced by these materials. On the other hand, earthworm and collembolan survival were unaffected by the degree of composting of the wastes. However, this pattern was clear in one of the composting procedures assessed, but less in the other, where the release of decomposition endproducts was lower due to its higher stability, indicating the sensitivity and usefulness of bioassays for the quality assessment of composts.« less

Effect-based trigger values for in vitro and in vivo bioassays performed on surface water extracts supporting the environmental quality standards (EQS) of the European Water Framework Directive.

PubMed

Escher, Beate I; Aїt-Aїssa, Selim; Behnisch, Peter A; Brack, Werner; Brion, François; Brouwer, Abraham; Buchinger, Sebastian; Crawford, Sarah E; Du Pasquier, David; Hamers, Timo; Hettwer, Karina; Hilscherová, Klára; Hollert, Henner; Kase, Robert; Kienle, Cornelia; Tindall, Andrew J; Tuerk, Jochen; van der Oost, Ron; Vermeirssen, Etienne; Neale, Peta A

2018-07-01

Effect-based methods including cell-based bioassays, reporter gene assays and whole-organism assays have been applied for decades in water quality monitoring and testing of enriched solid-phase extracts. There is no common EU-wide agreement on what level of bioassay response in water extracts is acceptable. At present, bioassay results are only benchmarked against each other but not against a consented measure of chemical water quality. The EU environmental quality standards (EQS) differentiate between acceptable and unacceptable surface water concentrations for individual chemicals but cannot capture the thousands of chemicals in water and their biological action as mixtures. We developed a method that reads across from existing EQS and includes additional mixture considerations with the goal that the derived effect-based trigger values (EBT) indicate acceptable risk for complex mixtures as they occur in surface water. Advantages and limitations of various approaches to read across from EQS are discussed and distilled to an algorithm that translates EQS into their corresponding bioanalytical equivalent concentrations (BEQ). The proposed EBT derivation method was applied to 48 in vitro bioassays with 32 of them having sufficient information to yield preliminary EBTs. To assess the practicability and robustness of the proposed approach, we compared the tentative EBTs with observed environmental effects. The proposed method only gives guidance on how to derive EBTs but does not propose final EBTs for implementation. The EBTs for some bioassays such as those for estrogenicity are already mature and could be implemented into regulation in the near future, while for others it will still take a few iterations until we can be confident of the power of the proposed EBTs to differentiate good from poor water quality with respect to chemical contamination. Copyright © 2018 Elsevier B.V. All rights reserved.

Genetic mouse embryo assay: improving performance and quality testing for assisted reproductive technology (ART) with a functional bioassay.

PubMed

Gilbert, Rebecca S; Nunez, Brandy; Sakurai, Kumi; Fielder, Thomas; Ni, Hsiao-Tzu

2016-03-24

Growing concerns about safety of ART on human gametes, embryos, clinical outcomes and long-term health of offspring require improved methods of risk assessment to provide functionally relevant assays for quality control testing and pre-clinical studies prior to clinical implementation. The one-cell mouse embryo assay (MEA) is the most widely used for development and quality testing of human ART products; however, concerns exist due to the insensitivity/variability of this bioassay which lacks standardization and involves subjective analysis by morphology alone rather than functional analysis of the developing embryos. We hypothesized that improvements to MEA by the use of functional molecular biomarkers could enhance sensitivity and improve detection of suboptimal materials/conditions. Fresh one-cell transgenic mouse embryos with green fluorescent protein (GFP) expression driven by Pou6f1 or Cdx2 control elements were harvested and cultured to blastocysts in varied test and control conditions to compare assessment by standard morphology alone versus the added dynamic expression of GFP for screening and selection of critical raw materials and detection of suboptimal culture conditions. Transgenic mouse embryos expressing functionally relevant biomarkers of normal early embryo development can be used to monitor the developmental impact of culture conditions. This novel approach provides a superior MEA that is more meaningful and sensitive for detection of embryotoxicity than morphological assessment alone.

Environmental Quality Research Fish and Aufwuchs Bioassay

DTIC Science & Technology

1981-01-01

reproductive success at WSF of shale JP-8 concentrations of 0. 51 ± 0. 30 mg/V. Results of continuous-flow bioassays of the WSF of hydrocarbon fuels to...42 Reproduction .................... ....................... 42 SALINE WATER BIOASSAYS OF HYDROCARBON FUELS ...... . . 47...and development and reproductive ability. Studies on JP-4, JP-8, and shale JP-8 have been conducted in saline water from San Francisco Bay at the

Environmental Quality Research Fish and Aufwuchs Bioassay

DTIC Science & Technology

1978-11-01

Disease was controlled by applications of Malachite Green to eggs upon their transfer from spawning aquaria into hatching aquaria. MINERAL QUALITY OF WATER...for 1 hr) and Malachite Green was administered just after transfer. Exposure to Malachite Green was for a period of 1-2 min (later lengthened to 4-5...that Bank A tanks did not become infected with the fungus that attacked the eggs in Bank B tanks was that the period of treatment with Malachite Green

A novel bioassay using the barnacle Amphibalanus amphitrite to evaluate chronic effects of aluminium, gallium and molybdenum in tropical marine receiving environments.

PubMed

van Dam, Joost W; Trenfield, Melanie A; Harries, Simon J; Streten, Claire; Harford, Andrew J; Parry, David; van Dam, Rick A

2016-11-15

A need exists for appropriate tools to evaluate risk and monitor potential effects of contaminants in tropical marine environments, as currently impact assessments are conducted by non-representative approaches. Here, a novel bioassay is presented that allows for the estimation of the chronic toxicity of contaminants in receiving tropical marine environments. The bioassay is conducted using planktonic larvae of the barnacle Amphibalanus amphitrite and is targeted at generating environmentally relevant, chronic toxicity data for water quality guideline derivation or compliance testing. The developmental endpoint demonstrated a consistently high control performance, validated through the use of copper as a reference toxicant. In addition, the biological effects of aluminium, gallium and molybdenum were assessed. The endpoint expressed high sensitivity to copper and moderate sensitivity to aluminium, whereas gallium and molybdenum exhibited no discernible effects, even at high concentrations, providing valuable information on the toxicity of these elements in tropical marine waters. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Quality of water types in Ukraine evaluated by WaterTox bioassays.

PubMed

Arkhipchuk, V V; Malinovskaya, M V

2002-01-01

The quality of river, ground-, and tap water was analyzed using the basic set of WaterTox bioassays [Daphnia (Daphnia magna), Hydra (Hydra attenuata), and lettuce (Lactuca sativa)] as well as two additional bioassays, onion (Allium cepa) and microalga (Selenastrum gracile). Samples of these waters were also concentrated fivefold using a solid-phase procedure. The results of the Daphnia and Hydra bioassays showed that the winter and spring concentrated and nonconcentrated samples from the Dnieper and Desna rivers, the main water supply sources for Kiev, were nontoxic. In spring, after concentration, the two river samples brought about the same relative decrease in the lettuce root length (by 35%, p < 0.001), where the Desna River sample considerably reduced (by 79.1%, p < 0.001) the number of microalga cells. Samples of groundwater from countryside wells studied in autumn in several villages of the Kiev region were toxic mainly to Hydra (sublethal effects were found in 11%-78%) and lettuce (the root length decreased 15%-56%). Studies of tap water samples from two of the largest cities of Ukraine, Kiev and Kharkiv, were found to be nontoxic to both plants, lettuce and onion, but showed increased sublethal and lethal effects on both animals, Daphnia and Hydra, as well as a reduced number of microalgae. Different bioassays were sensitive to varying degrees to different water types. This reinforces the necessity of using sets of bioassays in toxicity evaluation. In general, all the tested water samples demonstrated some toxicity. These data suggest that drinking water quality in Ukraine needs improvement. Copyright 2002 Wiley Periodicals, Inc.

Bioassays for Evaluating Water Quality-Technical Brief

EPA Pesticide Factsheets

Bioassays are a potential solution for assessing complex samples since they screen for total bioactivity for a given pathway or mode of action (MOA), such as estrogen receptor activation, in the samples. EPA has made considerable progress in the developmen

Environmental Quality Research, Use of Unicellular Algae for Evaluation of Potential Aquatic Contaminants

DTIC Science & Technology

1978-11-01

bioassays to determine the toxic and/or biostimulating effects of hydrazine and methylated hydrazines in various freshwater and marine aquatic environments...Table 2. TABLE 2 COMPOUNDS TESTED AND TEST CONDITIONS OF 1976/77 BIOASSAYS COMPOUND TEST CONDITIONS Type of Water Nutrient Level Hydrazine Freshwater ...AMRL-TR-78-86 ENVIRONMENTAL QUALITY RESEARCH, USE OF UNICELLULAR ALGAE FOR EVALUATION OF POTENTIAL AQUATIC CONTAMINANTS Third Annual Report JAN

International standards for monoclonal antibodies to support pre- and post-marketing product consistency: Evaluation of a candidate international standard for the bioactivities of rituximab

PubMed Central

Prior, Sandra; Hufton, Simon E.; Dougall, Thomas; Rigsby, Peter; Bristow, Adrian

2018-01-01

ABSTRACT The intrinsic complexity and heterogeneity of therapeutic monoclonal antibodies is built into the biosimilarity paradigm where critical quality attributes are controlled in exhaustive comparability studies with the reference medicinal product. The long-term success of biosimilars will depend on reassuring healthcare professionals and patients of consistent product quality, safety and efficacy. With this aim, the World Health Organization has endorsed the need for public bioactivity standards for therapeutic monoclonal antibodies in support of current controls. We have developed a candidate international potency standard for rituximab that was evaluated in a multi-center collaborative study using participants' own qualified Fc-effector function and cell-based binding bioassays. Dose-response curve model parameters were shown to reflect similar behavior amongst rituximab preparations, albeit with some differences in potency. In the absence of a common reference standard, potency estimates were in poor agreement amongst laboratories, but the use of the candidate preparation significantly reduced this variability. Our results suggest that the candidate rituximab standard can support bioassay performance and improve data harmonization, which when implemented will promote consistency of rituximab products over their life-cycles. This data provides the first scientific evidence that a classical standardization exercise allowing traceability of bioassay data to an international standard is also applicable to rituximab. However, we submit that this new type of international standard needs to be used appropriately and its role not to be mistaken with that of the reference medicinal product. PMID:28985159

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot.

PubMed

Glassman, Sydney I; Levine, Carrie R; DiRocco, Angela M; Battles, John J; Bruns, Thomas D

2016-05-01

After severe wildfires, pine recovery depends on ectomycorrhizal (ECM) fungal spores surviving and serving as partners for regenerating forest trees. We took advantage of a large, severe natural forest fire that burned our long-term study plots to test the response of ECM fungi to fire. We sampled the ECM spore bank using pine seedling bioassays and high-throughput sequencing before and after the California Rim Fire. We found that ECM spore bank fungi survived the fire and dominated the colonization of in situ and bioassay seedlings, but there were specific fire adapted fungi such as Rhizopogon olivaceotinctus that increased in abundance after the fire. The frequency of ECM fungal species colonizing pre-fire bioassay seedlings, post-fire bioassay seedlings and in situ seedlings were strongly positively correlated. However, fire reduced the ECM spore bank richness by eliminating some of the rare species, and the density of the spore bank was reduced as evidenced by a larger number of soil samples that yielded uncolonized seedlings. Our results show that although there is a reduction in ECM inoculum, the ECM spore bank community largely remains intact, even after a high-intensity fire. We used advanced techniques for data quality control with Illumina and found consistent results among varying methods. Furthermore, simple greenhouse bioassays can be used to determine which fungi will colonize after fires. Similar to plant seed banks, a specific suite of ruderal, spore bank fungi take advantage of open niche space after fires.

Ectomycorrhizal fungal spore bank recovery after a severe forest fire: some like it hot

PubMed Central

Glassman, Sydney I; Levine, Carrie R; DiRocco, Angela M; Battles, John J; Bruns, Thomas D

2016-01-01

After severe wildfires, pine recovery depends on ectomycorrhizal (ECM) fungal spores surviving and serving as partners for regenerating forest trees. We took advantage of a large, severe natural forest fire that burned our long-term study plots to test the response of ECM fungi to fire. We sampled the ECM spore bank using pine seedling bioassays and high-throughput sequencing before and after the California Rim Fire. We found that ECM spore bank fungi survived the fire and dominated the colonization of in situ and bioassay seedlings, but there were specific fire adapted fungi such as Rhizopogon olivaceotinctus that increased in abundance after the fire. The frequency of ECM fungal species colonizing pre-fire bioassay seedlings, post-fire bioassay seedlings and in situ seedlings were strongly positively correlated. However, fire reduced the ECM spore bank richness by eliminating some of the rare species, and the density of the spore bank was reduced as evidenced by a larger number of soil samples that yielded uncolonized seedlings. Our results show that although there is a reduction in ECM inoculum, the ECM spore bank community largely remains intact, even after a high-intensity fire. We used advanced techniques for data quality control with Illumina and found consistent results among varying methods. Furthermore, simple greenhouse bioassays can be used to determine which fungi will colonize after fires. Similar to plant seed banks, a specific suite of ruderal, spore bank fungi take advantage of open niche space after fires. PMID:26473720

The comparison of rapid bioassays for the assessment of urban groundwater quality.

PubMed

Dewhurst, R E; Wheeler, J R; Chummun, K S; Mather, J D; Callaghan, A; Crane, M

2002-05-01

Groundwater is a complex mixture of chemicals that is naturally variable. Current legislation in the UK requires that groundwater quality and the degree of contamination are assessed using chemical methods. Such methods do not consider the synergistic or antagonistic interactions that may affect the bioavailability and toxicity of pollutants in the environment. Bioassays are a method for assessing the toxic impact of whole groundwater samples on the environment. Three rapid bioassays, Eclox, Microtox and ToxAlert, and a Daphnia magna 48-h immobilisation test were used to assess groundwater quality from sites with a wide range of historical uses. Eclox responses indicated that the test was very sensitive to changes in groundwater chemistry; 77% of the results had a percentage inhibition greater than 90%. ToxAlert, although suitable for monitoring changes in water quality under laboratory conditions, produced highly variable results due to fluctuations in temperature and the chemical composition of the samples. Microtox produced replicable results that correlated with those from D. magna tests.

In vitro bioassays to evaluate complex chemical mixtures in recycled water

PubMed Central

Jia, Ai; Escher, Beate I.; Leusch, Frederic D.L.; Tang, Janet Y.M.; Prochazka, Erik; Dong, Bingfeng; Snyder, Erin M.; Snyder, Shane A.

2016-01-01

With burgeoning population and diminishing availability of freshwater resources, the world continues to expand the use of alternative water resources for drinking, and the quality of these sources has been a great concern for the public as well as public health professionals. In vitro bioassays are increasingly being used to enable rapid, relatively inexpensive toxicity screening that can be used in conjunction with analytical chemistry data to evaluate water quality and the effectiveness of water treatment. In this study, a comprehensive bioassay battery consisting of 36 bioassays covering 18 biological endpoints was applied to screen the bioactivity of waters of varying qualities with parallel treatments. Samples include wastewater effluent, ultraviolet light (UV) and/or ozone advanced oxidation processed (AOP) recycled water, and infiltrated recycled groundwater. Based on assay sensitivity and detection frequency in the samples, several endpoints were highlighted in the battery, including assays for genotoxicity, mutagenicity, estrogenic activity, glucocorticoid activity, aryl hydrocarbon receptor activity, oxidative stress response, and cytotoxicity. Attenuation of bioactivity was found to be dependent on the treatment process and bioassay endpoint. For instance, ozone technology significantly removed oxidative stress activity, while UV based technologies were most efficient for the attenuation of glucocorticoid activity. Chlorination partially attenuated genotoxicity and greatly decreased herbicidal activity, while groundwater infiltration efficiently attenuated most of the evaluated bioactivity with the exception of genotoxicity. In some cases, bioactivity (e.g., mutagenicity, genotoxicity, and arylhydrocarbon receptor) increased following water treatment, indicating that transformation products of water treatment may be a concern. Furthermore, several types of bioassays with the same endpoint were compared in this study, which could help guide the selection of optimized methods in future studies. Overall, this research indicates that a battery of bioassays can be used to support decision-making on the application of advanced water treatment processes for removal of bioactivity. PMID:25989591

In vitro bioassays to evaluate complex chemical mixtures in recycled water.

PubMed

Jia, Ai; Escher, Beate I; Leusch, Frederic D L; Tang, Janet Y M; Prochazka, Erik; Dong, Bingfeng; Snyder, Erin M; Snyder, Shane A

2015-09-01

With burgeoning population and diminishing availability of freshwater resources, the world continues to expand the use of alternative water resources for drinking, and the quality of these sources has been a great concern for the public as well as public health professionals. In vitro bioassays are increasingly being used to enable rapid, relatively inexpensive toxicity screening that can be used in conjunction with analytical chemistry data to evaluate water quality and the effectiveness of water treatment. In this study, a comprehensive bioassay battery consisting of 36 bioassays covering 18 biological endpoints was applied to screen the bioactivity of waters of varying qualities with parallel treatments. Samples include wastewater effluent, ultraviolet light (UV) and/or ozone advanced oxidation processed (AOP) recycled water, and infiltrated recycled groundwater. Based on assay sensitivity and detection frequency in the samples, several endpoints were highlighted in the battery, including assays for genotoxicity, mutagenicity, estrogenic activity, glucocorticoid activity, arylhydrocarbon receptor activity, oxidative stress response, and cytotoxicity. Attenuation of bioactivity was found to be dependent on the treatment process and bioassay endpoint. For instance, ozone technology significantly removed oxidative stress activity, while UV based technologies were most efficient for the attenuation of glucocorticoid activity. Chlorination partially attenuated genotoxicity and greatly decreased herbicidal activity, while groundwater infiltration efficiently attenuated most of the evaluated bioactivity with the exception of genotoxicity. In some cases, bioactivity (e.g., mutagenicity, genotoxicity, and arylhydrocarbon receptor) increased following water treatment, indicating that transformation products of water treatment may be a concern. Furthermore, several types of bioassays with the same endpoint were compared in this study, which could help guide the selection of optimized methods in future studies. Overall, this research indicates that a battery of bioassays can be used to support decision-making on the application of advanced water treatment processes for removal of bioactivity. Copyright © 2015 Elsevier Ltd. All rights reserved.

The nematode Caenorhabditis elegans as an integrated toxicological tool to assess water quality and pollution.

PubMed

Clavijo, Araceli; Kronberg, María Florencia; Rossen, Ariana; Moya, Aldana; Calvo, Daniel; Salatino, Santa Esmeralda; Pagano, Eduardo Antonio; Morábito, José Antonio; Munarriz, Eliana Rosa

2016-11-01

Determination of water quality status in rivers is critical to establish a sustainable water management policy. For this reason, over the last decades it has been recommended to perform integrated water assessments that include water quantities and physicochemical, ecological and toxicological tests. However, sometimes resources are limited and it is not possible to perform large-scale chemical determinations of pollutants or conduct numerous ecotoxicological tests. To overcome this problem we use and measure the growth, as a response parameter, of the soil nematode Caenorhabditis elegans to assess water quality in rivers. The C. elegans is a ubiquitous organism that has emerged as an important model organism in aquatic and soil toxicology research. The Tunuyán River Basin (Province of Mendoza, Argentina) has been selected as a representative traditional water monitoring system to test the applicability of the C. elegans toxicological bioassay to generate an integrated water quality evaluation. Jointly with the C. elegans toxic assays, physicochemical and bacteriological parameters were determined for each monitoring site. C. elegans bioassays help to identify different water qualities in the river basin. Multivariate statistical analysis (PCA and linear regression models) has allowed us to confirm that traditional water quality studies do not predict potential toxic effects on living organisms. On the contrary, physicochemical and bacteriological analyzes explain <62% of the C. elegans growth response variability, showing that ecotoxicological bioassays are important to obtain a realistic scenario of water quality threats. Our results confirm that the C. elegans bioassay is a sensible and suitable tool to assess toxicity and should be implemented in routine water quality monitoring. Copyright © 2016 Elsevier B.V. All rights reserved.

Field test of a bioassay procedure for assessing habitat quality on fish spawning grounds

USGS Publications Warehouse

Manny, Bruce A.; Jude, David J.; Eshenroder, Randy L.

1989-01-01

A bioassay procedure to assess habitat quality was tested on Port Austin reef in southern Lake Huron, a spawning area of lake trout Salvelinus namaycush. In 1986, Plexiglas incubators filled with fertilized lake trout eggs were buried by scuba divers in rock rubble at two sites. The incubators then were attached to chains between large trap-net anchors on the bottom and left over winter. At one site, egg hatch rate was significantly higher in incubators that remained buried in substrate (24%) than in incubators that were dislodged out onto the substrate (13%). At the other, more exposed site, no significant difference was found in percent hatch between eggs that incubated in (10%) and on (8%) the substrate. Percent hatch at both sites was significantly lower than that (40%) of eggs from the same source that were incubated in controlled laboratory conditions. In autumn, concentrations of dissolved ammonia, hydrogen sulfide, and nitrate near bottom and in the substrate posed no threat to lake trout embryos and were not correlated with hatch rate; concentrations differed significantly between the two sites. During winter, 15 cm of sediment settled from the water onto the reef but did not accumulate or smother the eggs. The bioassay procedure is easy to implement, is recommended for use in the Great Lakes, and could be adapted easily for use elsewhere.

Bioassay selection, experimental design and quality control/assurance for use in effluent assessment and control.

PubMed

Johnson, Ian; Hutchings, Matt; Benstead, Rachel; Thain, John; Whitehouse, Paul

2004-07-01

In the UK Direct Toxicity Assessment Programme, carried out in 1998-2000, a series of internationally recognised short-term toxicity test methods for algae, invertebrates and fishes, and rapid methods (ECLOX and Microtox) were used extensively. Abbreviated versions of conventional tests (algal growth inhibition tests, Daphnia magna immobilisation test and the oyster embryo-larval development test) were valuable for toxicity screening of effluent discharges and the identification of causes and sources of toxicity. Rapid methods based on chemiluminescence and bioluminescence were not generally useful in this programme, but may have a role where the rapid test has been shown to be an acceptable surrogate for a standardised test method. A range of quality assurance and control measures were identified. Requirements for quality control/assurance are most stringent when deriving data for characterising the toxic hazards of effluents and monitoring compliance against a toxicity reduction target. Lower quality control/assurance requirements can be applied to discharge screening and the identification of causes and sources of toxicity.

Hormetic versus toxic effects of vegetable tannin in a multitest study.

PubMed

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

2004-04-01

Tannin from mimosa trees (Acacia sp.) utilized in traditional leather tanning was tested for toxicity in sea urchin (Sphaerechinus granularis and Paracentrotus lividus) embryos and sperm, marine, and freshwater algae (Selenastrum capricornutum and Dunaliella tertiolecta), and Daphnia magna. Based on a two-step tanning procedure used in traditional tanneries, two mimosa tannin preparations, i.e., fresh tannin (FT) and used tannin (UT), were tested as suspensions. The early results in S. granularis embryos showed that UT exerted lower acute toxicity than FT, namely, 1 vs 100 mg/L, to obtain 100% mortality, respectively. Subsequent bioassays were conducted on fresh tannin water extracts (TWE) corresponding to nominal tannin concentrations ranging from 0.1 to 30 mg/L. Developmental toxicity, up to embryonic mortality was exerted by TWE at levels > 1 mg/L, S. granularis being more sensitive than P. lividus embryos/larvae. At the concentration of 0.1 mg/L, the frequencies of larval malformations were significantly lower than in controls. This positive stimulatory effect (currently termed as hormesis) was observed in extended numbers of culture replicates (up to 14) and was significant in the embryo cultures characterized by a relatively poor control quality (with < 70% viable larvae in controls), whereas this effect was not observed in good-quality cultures (with > or = 70% viable larvae in controls). Cytogenetic analysis of S. granularis embryos reared in FT or UT suspensions (1 mg/L to 1 g/L) showed mitotoxic effects (decrease in active mitoses per embryo) in FT-exposed, but not in UT-exposed embryos. Mitotic aberrations were significantly increased by 10 mg/L UT. Sperm fertilization success in both sea urchin species showed an increasing fertilization rate (FR) up to 0.3 mg/L TWE and a dose-related decrease in FR up to 30 mg/L. Again, the offspring of P. lividus sperm exposed to TWE (0.1 and 0.3 mg/L) showed a decrease in larval malformations compared to controls, whereas a dose-related increase in developmental defects was observed in the offspring of P. lividus sperm exposed to higher TWE levels (1 to 30 mg/L). Algal cell growth bioassays in two species (S. capricornutum and D. tertiolecta) also showed a maximum growth at TWE levels ranging from 0.3 to 3 mg/L and a subsequent decline up to 30 mg/L TWE. D. magna bioassays resulted in daphnid immobilization by TWE concentrations ranging from 100 to 300 mg/L. The results demonstrate that tannins utilized in traditional leather tanning industry may raise concern of environmental damage at relatively high concentrations, whereas low-level tannins may result in hormetic effects. The present study also points to the need for bioassay design that should rely on adequate criteria in control quality, allowing to detect both inhibitory and hormetic effects.

Development of a bioanalytical test battery for water quality monitoring: Fingerprinting identified micropollutants and their contribution to effects in surface water.

PubMed

Neale, Peta A; Altenburger, Rolf; Aït-Aïssa, Selim; Brion, François; Busch, Wibke; de Aragão Umbuzeiro, Gisela; Denison, Michael S; Du Pasquier, David; Hilscherová, Klára; Hollert, Henner; Morales, Daniel A; Novák, Jiří; Schlichting, Rita; Seiler, Thomas-Benjamin; Serra, Helene; Shao, Ying; Tindall, Andrew J; Tollefsen, Knut Erik; Williams, Timothy D; Escher, Beate I

2017-10-15

Surface waters can contain a diverse range of organic pollutants, including pesticides, pharmaceuticals and industrial compounds. While bioassays have been used for water quality monitoring, there is limited knowledge regarding the effects of individual micropollutants and their relationship to the overall mixture effect in water samples. In this study, a battery of in vitro bioassays based on human and fish cell lines and whole organism assays using bacteria, algae, daphnids and fish embryos was assembled for use in water quality monitoring. The selection of bioassays was guided by the principles of adverse outcome pathways in order to cover relevant steps in toxicity pathways known to be triggered by environmental water samples. The effects of 34 water pollutants, which were selected based on hazard quotients, available environmental quality standards and mode of action information, were fingerprinted in the bioassay test battery. There was a relatively good agreement between the experimental results and available literature effect data. The majority of the chemicals were active in the assays indicative of apical effects, while fewer chemicals had a response in the specific reporter gene assays, but these effects were typically triggered at lower concentrations. The single chemical effect data were used to improve published mixture toxicity modeling of water samples from the Danube River. While there was a slight increase in the fraction of the bioanalytical equivalents explained for the Danube River samples, for some endpoints less than 1% of the observed effect could be explained by the studied chemicals. The new mixture models essentially confirmed previous findings from many studies monitoring water quality using both chemical analysis and bioanalytical tools. In short, our results indicate that many more chemicals contribute to the biological effect than those that are typically quantified by chemical monitoring programs or those regulated by environmental quality standards. This study not only demonstrates the utility of fingerprinting single chemicals for an improved understanding of the biological effect of pollutants, but also highlights the need to apply bioassays for water quality monitoring in order to prevent underestimation of the overall biological effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Importance of Practice in the Development of Statistics.

DTIC Science & Technology

1983-01-01

RESOLUTION TEST CHART NATIONAL BUREAU OIF STANDARDS 1963 -A NRC Technical Summary Report #2471 C THE IMORTANCE OF PRACTICE IN to THE DEVELOPMENT OF STATISTICS...component analysis, bioassay, limits for a ratio, quality control, sampling inspection, non-parametric tests , transformation theory, ARIMA time series...models, sequential tests , cumulative sum charts, data analysis plotting techniques, and a resolution of the Bayes - frequentist controversy. It appears

40 CFR 227.6 - Constituents prohibited as other than trace contaminants.

Code of Federal Regulations, 2011 CFR

2011-07-01

... included in the applicable marine water quality criteria, bioassay results on the liquid phase of the waste... possibility of danger associated -with their bioaccumulation in marine -organisms. (c) The potential for... of results of bioassays on liquid, suspended particulate, and solid phases of wastes according to...

Bioassays for Evaluating Water Quality: Screening for total bioactivity to assess water safety

EPA Science Inventory

Bioassays are a potential solution for assessing complex samples since they screen for total bioactivity for a given pathway or mode of action (MOA), such as estrogen receptor activation, in the samples. Overall, they can account for the three challenges listed above, and can sim...

A Bioassay System Using Bioelectric Signals from Small Fish

NASA Astrophysics Data System (ADS)

Terawaki, Mitsuru; Soh, Zu; Hirano, Akira; Tsuji, Toshio

Although the quality of tap water is generally examined using chemical assay, this method cannot be used for examination in real time. Against such a background, the technique of fish bioassay has attracted attention as an approach that enables constant monitoring of aquatic contamination. The respiratory rhythms of fish are considered an efficient indicator for the ongoing assessment of water quality, since they are sensitive to chemicals and can be indirectly measured from bioelectric signals generated by breathing. In order to judge aquatic contamination accurately, it is necessary to measure bioelectric signals from fish swimming freely as well as to stably discriminate measured signals, which vary between individuals. However, no bioassay system meeting the above requirements has yet been established. This paper proposes a bioassay system using bioelectric signals generated from small fish in free-swimming conditions. The system records signals using multiple electrodes to cover the extensive measurement range required in a free-swimming environment, and automatically discriminates changes in water quality from signal frequency components. This discrimination is achieved through an ensemble classification method using probability neural networks to solve the problem of differences between individual fish. The paper also reports on the results of related validation experiments, which showed that the proposed system was able to stably discriminate between water conditions before and after bleach exposure.

Assessment of sediment quality in dredged and undredged areas of the Trenton Channel of the Detroit River, Michigan USA, using the sediment quality triad

USGS Publications Warehouse

Besser, John M.; Giesy, John P.; Kubitz, Jody A.; Verbrugge, David A.; Coon, Thomas G.; Braselton, W. Emmett

1996-01-01

The “sediment quality triad” approach was used to assess the effects of dredging on the sediment quality of a new marina in the Trenton Channel of the Detroit River, and to evaluate spatial and temporal variation in sediment quality in the Trenton Channel. Samples were collected in November of 1993 (10 months after dredging) and characterized by chemical analysis, sediment bioassays, and assessment of benthic invertebrate communities. The three study components indicated little difference in sediment quality at dredged sites in the marina relative to nearby areas in the Trenton Channel, and little change in sediment quality of Trenton Channel sites relative to conditions reported in the mid-1980s. These results suggest that improvement in sediment quality in the Trenton Channel, due to dredging or natural processes, will depend on elimination of sediment “hot spots” and other upstream contaminant sources. Concentrations of chemical contaminants, especially metals and polycyclic aromatic hydrocarbons, exceeded concentrations associated with effects on biota and were significantly correlated with results of sediment bioassays and characteristics of benthic communities. Laboratory sediment bioassays with Hyalella azteca andChironomus tentans produced better discrimination among sites with differing degrees of contamination than did characterization of benthic communities, which were dominated by oligochaetes at all sites in the marina and the Trenton Channel.

Bioassay battery interlaboratory investigation of emerging contaminants in spiked water extracts - Towards the implementation of bioanalytical monitoring tools in water quality assessment and monitoring.

PubMed

Di Paolo, Carolina; Ottermanns, Richard; Keiter, Steffen; Ait-Aissa, Selim; Bluhm, Kerstin; Brack, Werner; Breitholtz, Magnus; Buchinger, Sebastian; Carere, Mario; Chalon, Carole; Cousin, Xavier; Dulio, Valeria; Escher, Beate I; Hamers, Timo; Hilscherová, Klára; Jarque, Sergio; Jonas, Adam; Maillot-Marechal, Emmanuelle; Marneffe, Yves; Nguyen, Mai Thao; Pandard, Pascal; Schifferli, Andrea; Schulze, Tobias; Seidensticker, Sven; Seiler, Thomas-Benjamin; Tang, Janet; van der Oost, Ron; Vermeirssen, Etienne; Zounková, Radka; Zwart, Nick; Hollert, Henner

2016-11-01

Bioassays are particularly useful tools to link the chemical and ecological assessments in water quality monitoring. Different methods cover a broad range of toxicity mechanisms in diverse organisms, and account for risks posed by non-target compounds and mixtures. Many tests are already applied in chemical and waste assessments, and stakeholders from the science-police interface have recommended their integration in regulatory water quality monitoring. Still, there is a need to address bioassay suitability to evaluate water samples containing emerging pollutants, which are a current priority in water quality monitoring. The presented interlaboratory study (ILS) verified whether a battery of miniaturized bioassays, conducted in 11 different laboratories following their own protocols, would produce comparable results when applied to evaluate blinded samples consisting of a pristine water extract spiked with four emerging pollutants as single chemicals or mixtures, i.e. triclosan, acridine, 17α-ethinylestradiol (EE2) and 3-nitrobenzanthrone (3-NBA). Assays evaluated effects on aquatic organisms from three different trophic levels (algae, daphnids, zebrafish embryos) and mechanism-specific effects using in vitro estrogenicity (ER-Luc, YES) and mutagenicity (Ames fluctuation) assays. The test battery presented complementary sensitivity and specificity to evaluate the different blinded water extract spikes. Aquatic organisms differed in terms of sensitivity to triclosan (algae > daphnids > fish) and acridine (fish > daphnids > algae) spikes, confirming the complementary role of the three taxa for water quality assessment. Estrogenicity and mutagenicity assays identified with high precision the respective mechanism-specific effects of spikes even when non-specific toxicity occurred in mixture. For estrogenicity, although differences were observed between assays and models, EE2 spike relative induction EC 50 values were comparable to the literature, and E2/EE2 equivalency factors reliably reflected the sample content. In the Ames, strong revertant induction occurred following 3-NBA spike incubation with the TA98 strain, which was of lower magnitude after metabolic transformation and when compared to TA100. Differences in experimental protocols, model organisms, and data analysis can be sources of variation, indicating that respective harmonized standard procedures should be followed when implementing bioassays in water monitoring. Together with other ongoing activities for the validation of a basic bioassay battery, the present study is an important step towards the implementation of bioanalytical monitoring tools in water quality assessment and monitoring. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biological and functional responses of in situ bioassays with Chironomus riparius larvae to assess river water quality and contamination.

PubMed

Faria, Mafalda S; Ré, Ana; Malcato, João; Silva, Paula C L D; Pestana, João; Agra, Ana R; Nogueira, António J A; Soares, Amadeu M V M

2006-12-01

Single species responses have the potential to measure impacts at earlier stages than more traditional methods based in community structure. This study evaluates a bioassay with biological (survival, development, growth) and functional (post-exposure feeding rate) responses of Chironomus riparius larvae to assess water quality and contamination in rivers. The bioassay with C. riparius third instar larvae was performed, in autumn and spring, in reference sites and in organic and metal contaminated sites in Portuguese rivers. Biotic, physical and chemical parameters were determined for each site. The relationship between both bioassays responses and biotic indices (IBMWP and IASPT) and the physical and chemical parameters of respective sites were determined. In general biotic indices were able to discriminate between contaminated and not contaminated sites although they demonstrated a poor ability to detect low level of metal contamination during autumn. IASPT was negatively related to ammonia concentrations in both seasons. No significant differences in survival and post-exposure feeding rate were found between sites. Development was inhibited in the most metal contaminated site during autumn, but pH and ammonia concentrations in water accounted for 82% of developmental variation during this season. Growth was highly inhibited in the most metal contaminated site during both seasons. In autumn, growth was also inhibited in the low metal contaminated site and, during this season, pH and Mn and Fe concentrations in water samples accounted for 97% of growth variation between sites. The results suggest that in situ bioassay with C. riparius larvae using growth as the endpoint is a responsive and suitable tool that can be used as bioindicator of metal pollution and to biomonitor water quality in metal contaminated rivers.

Review of Bioassays for Monitoring Fate and Transport ofEstrogenic Endocrine Disrupting Compounds in Water

DOE Office of Scientific and Technical Information (OSTI.GOV)

CGCampbell@lbl.gov

Endocrine disrupting compounds (EDCs) are recognizedcontaminants threatening water quality. Despite efforts in sourceidentification, few strategies exist for characterization or treatment ofthis environmental pollution. Given that there are numerous EDCs that cannegatively affect humans and wildlife, general screening techniques likebioassays and biosensors provide an essential rapid and intensiveanalysis capacity. Commonly applied bioassays include the ELISA and YESassays, but promising technologies include ER-CALUXa, ELRA, Endotecta,RIANA, and IR-bioamplification. Two biosensors, Endotecta and RIANA, arefield portable using non-cellular biological detection strategies.Environmental management of EDCs in water requires integration ofbiosensors and bioassays for monitoring and assessment.

Bioassay of formulations of Bacillus thuringiensis for use in forestry: panel discussion of the role of the bioassay in standardizing formulations of B. thuringiensis

Treesearch

H. T. Dulmage; C. C. Beegle; N. R. Dubois

1985-01-01

The panel discussed various aspects of Bacillus thuringiensis formulations and fermentations and concluded that the only means at present of standardizing these formulations or discovering more potent strains of the Bacillus is through carefully controlled bioassays.

Effect-directed analysis supporting monitoring of aquatic ...

EPA Pesticide Factsheets

Aquatic environments are often contaminated with complex mixtures of chemicals that may pose a risk to ecosystems and human health. This contamination cannot be addressed with target analysis alone but tools are required to reduce this complexity and identify those chemicals that might cause adverse effects. Effect-directed analysis (EDA) is designed to meet this challenge and faces increasing interest in water and sediment quality monitoring. Thus, the present paper summarizes current experience with the EDA approach and the tools required,and provides practical advice on their application. The paper highlights the need for proper problem formulation and gives general advice for study design. As the EDA approach is directed by toxicity, basic principles for the selection of bioassays are given as well as a comprehensive compilation of appropriate assays, includingtheir strengths andweaknesses. A specific focus is given to strategies for sampling, extraction and bioassay dosing since they strongly impact prioritization of toxicants in EDA. Reduction of sample complexity mainly relies onfractionation procedures, which are discussed in this paper, including quality assurance and quality control. Automated combinations of fractionation, biotesting and chemical analysis using so-called hyphenated tools can enhance the throughput and might reduce the risk of artifacts in laboratory work. The key to determiningthe chemical structures causing effects is analytical toxi

In situ bioassays with Chironomus riparius larvae to biomonitor metal pollution in rivers and to evaluate the efficiency of restoration measures in mine areas.

PubMed

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

2008-01-01

In this study we evaluate the ability of an in situ bioassay with Chironomus riparius larvae, using larval development and growth as endpoints, to biomonitor water quality and to assess the biological recovery of metal contaminated freshwater ecosystems of mine areas that are subject of restoration measures. The bioassay was carried out in streams located near an abandoned goldmine in North Portugal, throughout an environmental rehabilitation of the mine (2002-2004). During this period, a decrease in the inhibition of larval growth in the metal contaminated stream was observed. The bioassay was also performed in streams located near an active tungsten mine in Central Portugal. Larval growth and development were highly inhibited in the stream that receives acid drainage from the tungsten mine and treated water from the AMD treatment station. The results indicate that the bioassay can be used to evaluate the efficiency of environmental restoration measures in mining areas.

Repellent activities of dichloromethane extract of Allium sativum (garlic) (Liliaceae) against Hyalomma rufipes (Acari).

PubMed

Nchu, Felix; Magano, Solomon R; Eloff, Jacobus N

2016-12-02

Dichloromethane (DCM) extract of garlic (Allium sativum Linn.) bulbs was assessed for its repellent effect against the hard tick, Hyalomma rufipes (Acari: Ixodidae) using two tick behavioural bioassays; Type A and Type B repellency bioassays, under laboratory conditions. These bioassays exploit the questing behaviour of H. rufipes, a tick that in nature displays ambush strategy, seeking its host by climbing up on vegetation and attaching to a passing host. One hundred microlitres (100 µL) of the test solution containing DCM extract of garlic bulbs and DCM at concentrations of 0.35%, 0.7% or 1.4% w/v were evaluated. DCM only was used for control. Tick repellency increased significantly (R2 = 0.98) with increasing concentration (40.03% - 86.96%) yielding an EC50 of 0.45% w/v in Type B repellency bioassay. At concentration of 1.4% w/v, the DCM extract of garlic bulbs produced high repellency index of 87% (male ticks) and 87.5% (female ticks) in the Type A repellency bioassay. Only 4% avoidance of male ticks or female ticks was recorded in the Type B repellency bioassay. In the corresponding controls, the mean numbers of non-repelled male or female ticks were 80% and 41 males or 38 females of 50 ticks in the Type A and Type B repellency bioassays, respectively. The variations in the results could be attributed to the difference in tick repellent behaviours that were assessed by the two repellency bioassays; the Type A repellency bioassay assessed repellent effect of garlic extracts without discriminating between deterrence and avoidance whereas the Type B repellency bioassay only assessed avoidance response. Generally, DCM extract of garlic was repellent against H. rufipes, albeit weak tick repellency was obtained in the Type B repellency bioassay. Furthermore, this study established that the tick repellent activity of garlic extracts is predominantly by deterrence.

Comparison of five in vitro bioassays to measure estrogenic activity in environmental waters.

PubMed

Leusch, Frederic D L; de Jager, Christiaan; Levi, Yves; Lim, Richard; Puijker, Leo; Sacher, Frank; Tremblay, Louis A; Wilson, Vickie S; Chapman, Heather F

2010-05-15

Bioassays are well established in the pharmaceutical industry and single compound analysis, but there is still uncertainty about their usefulness in environmental monitoring. We compared the responses of five bioassays designed to measure estrogenic activity (the yeast estrogen screen, ER-CALUX, MELN, T47D-KBluc, and E-SCREEN assays) and chemical analysis on extracts from four different water sources (groundwater, raw sewage, treated sewage, and river water). All five bioassays displayed similar trends and there was good agreement with analytical chemistry results. The data from the ER-CALUX and E-SCREEN bioassays were robust and predictable, and well-correlated with predictions from chemical analysis. The T47D-KBluc appeared likewise promising, but with a more limited sample size it was less compelling. The YES assay was less sensitive than the other assays by an order of magnitude, which resulted in a larger number of nondetects. The MELN assay was less predictable, although the possibility that this was due to laboratory-specific difficulties cannot be discounted. With standardized bioassay data analysis and consistency of operating protocols, bioanalytical tools are a promising advance in the development of a tiered approach to environmental water quality monitoring.

Bioassay of Surface Quality/Chesapeake Bay, Maryland

DTIC Science & Technology

1995-02-01

macroinvertebrate bioassay (Lenat, 1988 ; Resh, 1984). A simplified method, based on macroinvertebrates, has been developed for use by volunteer groups...338. ) Glcason, IHenry A . and A . Cronquist . 1963. ManualofVascular Plants of Northeastern United States S -- ’ and Adjacent Canada. New York Botanical...distribution unlimited The views, opinions and/or findings contained in this report arethose of the author( a ) and should not be construed as an official

Applied Ecology Seminar. Training Manual.

ERIC Educational Resources Information Center

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

Presented is material on planning, administering, collecting, evaluating, interpreting, and reporting biological data related to water quality studies in both fresh and marine waters. Topics include aquatic ecology, water pollution, taxonomy, bacteriology, bioassays, water quality enhancement, and administration of water quality standards. Each of…

[Application study of human sperm motility bioassay in IVF laboratory quality control].

PubMed

Cai, Xia; Pomeroy, Kimball O; Mattox, John H

2006-07-01

To investigate the sensitivity of human sperm survival bioassay to using known concentrations of potential toxin of formalin and to elevate the application value of human sperm motility assay as a quality control method in detecting the components used in IVF program. Fresh semen was obtained from healthy males at andrology laboratory by masturbation. Sperm was processed on a gradient column of isolate medium and PBS medium. In experiment 1, the medium with 0.25%, 0.75% concentration of formalin and control medium were added to the Falcon culture tubes containing HTF medium with or without 0.3% bovine albumin serum and with or without light mineral oil. In experiment 2, in 3 types of culture tubes containing HTF medium with or without 0.3% bovine albumin serum and with or without light mineral oil, the sperm was exposed to each culture tube and cultured for 24 and 48 hrs at room temperature, and the motile sperms were counted under the microscope. The average sperm motility index in the HTF medium with 0.25% formalin at 24 hrs was 0.594 +/- 0.331, significantly higher than in the HTF medium with 0.75% formalin (0.450 +/- 0.284) (P < 0.01). In the medium containing 0.25% and 0.75% formalin with 0.3% bovine albumin serum and light mineral oil, the average sperm survival indexes were 0.683 +/- 0.334 and 0.527 +/- 0.345, respectively, higher than without bovine albumin serum and light mineral oil (0.394 +/- 0.311 and 0.424 +/- 0.311). The average sperm index of 7 ml tissue culture tube made in Denmark was 0.677 +/- 0.335, higher than the other two types of culture tubes made in the USA (0.551 +/- 0.317 and 0.596 +/- 0.327) (P < 0.001). When the sperm cultured in the medium with 0.3% bovine albumin serum and light mineral oil, the average sperm survival indexes were 0.821 +/- 0.259 and 0.645 +/- 0.335, respectively, higher than without bovine albumin serum or light mineral oil (0.571 +/- 0.321 and 0.395 +/- 0.245) (P < 0.01). The sperm survival bioassay is a sensitivity quality control method to detect the components in the IVF laboratory. The 7 ml tissue culture tube made in Denmark is most suitable for culturing human embryos. Sperm can be protected when cultured in the medium with 0.3% albumin bovine serum and light mineral oil.

A new in vitro bioassay system for discovery and quantitative evaluation of mosquito repellents

USDA-ARS?s Scientific Manuscript database

Mosquitoes are vectors of many pathogens that cause human diseases. Although prevention and control of immature stages is the best method to control mosquitoes, repellents play a significant role in reducing the risk of these diseases by preventing mosquito bites. The In vitro K & D bioassay system ...

Characterization of quality of sediments from Paranaguá Bay (Brazil) by combined in vitro bioassays and chemical analyses.

PubMed

Rizzi, Juliane; Pérez-Albaladejo, Elisabet; Fernandes, Denise; Contreras, Javier; Froehner, Sandro; Porte, Cinta

2017-07-01

The present study characterizes the quality of sediments from the Paranaguá Estuarine Complex (South Brazil). Polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) were determined in sediment samples together with a series of different in vitro bioassays. The fish hepatoma cell line (PLHC-1) was used to determine the presence of cytotoxic compounds and CYP1A- and oxidative stress-inducing agents in sediment extracts. Ovarian microsomal fractions from sea bass (Dicentrarchus labrax) were used to detect the presence of endocrine disrupters that interfered with the synthesis of estrogens (ovarian CYP19). Despite the relatively low levels of pollutants and no evidence of negative effects based on guideline levels, sediments collected close to harbors were enriched with CYP1A-inducing agents and they showed higher cytotoxicity. In contrast, sediments from internal areas inhibited CYP19 activity, which suggests the presence of endocrine disrupters at these sites. Overall, the selected bioassays and the chemistry data led to the identification of potentially impacted areas along the Paranaguá Estuarine Complex that would require further action to improve their environmental quality. Environ Toxicol Chem 2017;36:1811-1819. © 2016 SETAC. © 2016 SETAC.

Separation of pigment formulations by high-performance thin-layer chromatography with automated multiple development.

PubMed

Stiefel, Constanze; Dietzel, Sylvia; Endress, Marc; Morlock, Gertrud E

2016-09-02

Food packaging is designed to provide sufficient protection for the respective filling, legally binding information for the consumers like nutritional facts or filling information, and an attractive appearance to promote the sale. For quality and safety of the package, a regular quality control of the used printing materials is necessary to get consistently good print results, to avoid migration of undesired ink components into the food and to identify potentially faulty ink batches. Analytical approaches, however, have hardly been considered for quality assurance so far due to the lack of robust, suitable methods for the analysis of rarely soluble pigment formulations. Thus, a simple and generic high-performance thin-layer chromatography (HPTLC) method for the separation of different colored pigment formulations was developed on HPTLC plates silica gel 60 by automated multiple development. The gradient system provided a sharp resolution for differently soluble pigment constituents like additives and coating materials. The results of multi-detection allowed a first assignment of the differently detectable bands to particular chemical substance classes (e.g., lipophilic components), enabled the comparison of different commercially available pigment batches and revealed substantial variations in the composition of the batches. Hyphenation of HPTLC with high resolution mass spectrometry and infrared spectroscopy allowed the characterization of single unknown pigment constituents, which may partly be responsible for known quality problems during printing. The newly developed, precise and selective HPTLC method can be used as part of routine quality control for both, incoming pigment batches and monitoring of internal pigment production processes, to secure a consistent pigment composition resulting in consistent ink quality, a faultless print image and safe products. Hyphenation of HPTLC with the A. fischeri bioassay gave first information on the bioactivity or rather on the toxicological potential of different compounds of the pigment formulations. The results of the bioassay might be helpful to choose pigment compositions that provide both, a high printing quality but at the same time guarantee a high consumer safety, especially in regard to smaller pigment components, which tend to migrate through the packaging. Copyright © 2016 Elsevier B.V. All rights reserved.

Methods for conducting bioassays using embryos and larvae of Pacific herring, Clupea pallasi.

PubMed

Dinnel, Paul A; Middaugh, Douglas P; Schwarck, Nathan T; Farren, Heather M; Haley, Richard K; Hoover, Richard A; Elphick, James; Tobiason, Karen; Marshall, Randall R

2011-02-01

The rapid decrease of several stocks of Pacific herring, Clupea pallasi, in Puget Sound, Washington, has led to concerns about the effects of industrial and nonpoint source contamination on the embryo and larval stages of this and related forage fish species. To address these concerns, the state of Washington and several industries have funded efforts to develop embryo and larval bioassay protocols that can be used by commercial laboratories for routine effluent testing. This article presents the results of research to develop herring embryo and larval bioassay protocols. Factors evaluated during protocol development included temperature, salinity, dissolved oxygen (DO), light intensity, photoperiod, larval feeding regimes, use of brine and artificial sea salts, gonad sources, collection methods, and egg quality.

Larval development ratio test with the calanoid copepod Acartia tonsa as a new bioassay to assess marine sediment quality.

PubMed

Buttino, Isabella; Vitiello, Valentina; Macchia, Simona; Scuderi, Alice; Pellegrini, David

2018-03-01

The copepod Acartia tonsa was used as a model species to assess marine sediment quality. Acute and chronic bioassays, such as larval development ratio (LDR) and different end-points were evaluated. As a pelagic species, A. tonsa is mainly exposed to water-soluble toxicants and bioassays are commonly performed in seawater. However, an interaction among A. tonsa eggs and the first larval stages with marine sediments might occur in shallow water environments. Here we tested two different LDR protocols by incubating A. tonsa eggs in elutriates and sediments coming from two areas located in Tuscany Region (Central Italy): Livorno harbour and Viareggio coast. The end-points analyzed were larval mortality (LM) and development inhibition (DI) expressed as the percentage of copepods that completed the metamorphosis from nauplius to copepodite. Aims of this study were: i) to verify the suitability of A. tonsa copepod for the bioassay with sediment and ii) to compare the sensitivity of A. tonsa exposed to different matrices, such as water and sediment. A preliminary acute test was also performed. Acute tests showed the highest toxicity of Livorno's samples (two out of three) compared to Viareggio samples, for which no effect was observed. On the contrary, LDR tests with sediments and elutriates revealed some toxic effects also for Viareggio's samples. Results were discussed with regards to the chemical characterization of the samples. Our results indicated that different end-points were affected in A. tonsa, depending on the matrices to which the copepods were exposed and on the test used. Bioassays with elutriates and sediments are suggested and LDR test could help decision-makers to identify a more appropriate management of dredging materials. Copyright © 2017 Elsevier Inc. All rights reserved.

Development, Optimization, and Validation of a Microplate Bioassay for Relative Potency Determination of Linezolid Using a Design Space Concept, and its Measurement Uncertainty.

PubMed

Saviano, Alessandro Morais; Francisco, Fabiane Lacerda; Ostronoff, Celina Silva; Lourenço, Felipe Rebello

2015-01-01

The aim of this study was to develop, optimize, and validate a microplate bioassay for relative potency determination of linezolid in pharmaceutical samples using quality-by-design and design space approaches. In addition, a procedure is described for estimating relative potency uncertainty based on microbiological response variability. The influence of culture media composition was studied using a factorial design and a central composite design was adopted to study the influence of inoculum proportion and triphenyltetrazolium chloride in microbial growth. The microplate bioassay was optimized regarding the responses of low, medium, and high doses of linezolid, negative and positive controls, and the slope, intercept, and correlation coefficient of dose-response curves. According to optimization results, design space ranges were established using: (a) low (1.0 μg/mL), medium (2.0 μg/mL), and high (4.0 μg/mL) doses of pharmaceutical samples and linezolid chemical reference substance; (b) Staphylococcus aureus ATCC 653 in an inoculum proportion of 10%; (c) antibiotic No. 3 culture medium pH 7.0±0.1; (d) 6 h incubation at 37.0±0.1ºC; and (e) addition of 50 μL of 0.5% (w/v) triphenyltetrazolium chloride solution. The microplate bioassay was linear (r2=0.992), specific, precise (repeatability RSD=2.3% and intermediate precision RSD=4.3%), accurate (mean recovery=101.4%), and robust. The overall measurement uncertainty was reasonable considering the increased variability inherent in microbiological response. Final uncertainty was comparable with those obtained with other microbiological assays, as well as chemical methods.

Estimation of internal exposure to 99Mo in nuclear medicine patients.

PubMed

Silva, I C O A; Lucena, E A; Souza, W O; Dantas, A L A; Dantas, B M

2010-05-10

(99m)Tc is the most widely used radionuclide in nuclear medicine. It is obtained by elution of (99)Mo-(99m)Tc generators. Depending on the quality of the generator and its integrity, (99)Mo may be extracted from the column during the elution process, becoming a radionuclidic impurity in the (99m)Tc eluate. This fact would impart an unnecessary dose to the patients submitted to diagnostic procedures. The aim of this work is to evaluate (99)Mo incorporation and internal effective doses in nuclear medicine patients through bioassay techniques, providing information on the metabolism of molybdenum in humans. A methodology based on in vivo and in vitro measurements was developed. In vivo measurements were performed with a NaI detector installed in the IRD WBC. Urine samples were analysed with a HPGe at the IRD bioassay laboratory. Patients showed detectable activities of (99)Mo in whole body and urine. Results were interpreted with AIDE software. Estimated incorporation was compared to predicted values based on ICRP model. Effective doses were in the order of micro sieverts. Results suggest the need to implement a routine quality control program of radionuclidic impurity of (99)Mo in (99m)Tc eluates to be conducted by radiopharmacy laboratories of nuclear medicine centers.

Genotoxic and mutagenic effects of polluted surface water in the midwestern region of Brazil using animal and plant bioassays

PubMed Central

Dourado, Priscila Leocádia Rosa; da Rocha, Monyque Palagano; Roveda, Liriana Mara; Raposo, Jorge Luiz; Cândido, Liliam Sílvia; Cardoso, Claudia Andréa Lima; Morales, Maria Aparecida Marin; de Oliveira, Kelly Mari Pires; Grisolia, Alexeia Barufatti

2016-01-01

Abstract This study aimed to evaluate DNA damage in animal and plant cells exposed to water from the Água Boa stream (Dourados, Mato Grosso do Sul, Brazil) by using bioassays, and to identify the chemical compounds in the water to determine the water quality in the area. Through the cytotoxicity bioassay with Allium cepa, using micronucleus test, and comet assay, using Astyanax altiparanae fish, the results indicated that biological samples were genetically altered. Micronuclei were observed in erythrocytes of A. altiparanae after exposure to water from locations close to industrial waste discharge. The highest DNA damage observed with the comet assay in fish occurred with the exposure to water from locations where the presence of metals (Cu, Pb, Cd, Ni) was high, indicating the possibility of genotoxic effects of these compounds. Thus, these results reinforce the importance of conducting genotoxicity tests for developing management plans to improve water quality, and indicate the need for waste management before domestic and industrial effluents are released into the rivers and streams. PMID:27801481

A versatile and low-cost open source pipetting robot for automation of toxicological and ecotoxicological bioassays

PubMed Central

Seiler, Thomas-Benjamin; Ruchter, Nadine; Schumann, Mark; Döring, Ricarda; Cofalla, Catrina; Ostfeld, Avi; Salomons, Elad; Schüttrumpf, Holger; Hollert, Henner

2017-01-01

In the past decades, bioassays and whole-organism bioassay have become important tools not only in compliance testing of industrial chemicals and plant protection products, but also in the monitoring of environmental quality. With few exceptions, such test systems are discontinuous. They require exposure of the biological test material in small units, such as multiwell plates, during prolonged incubation periods, and do not allow online read-outs. It is mostly due to these shortcomings that applications in continuous monitoring of, e.g., drinking or surface water quality are largely missing. We propose the use of pipetting robots that can be used to automatically exchange samples in multiwell plates with fresh samples in a semi-static manner, as a potential solution to overcome these limitations. In this study, we developed a simple and low-cost, versatile pipetting robot constructed partly using open-source hardware that has a small footprint and can be used for online monitoring of water quality by means of an automated whole-organism bioassay. We tested its precision in automated 2-fold dilution series and used it for exposure of zebrafish embryos (Danio rerio)–a common model species in ecotoxicology—to cadmium chloride and permethrin. We found that, compared to conventional static or semi-static exposure scenarios, effects of the two chemicals in zebrafish embryos generally occurred at lower concentrations, and analytically verified that the increased frequency of media exchange resulted in a greater availability of the chemical. In combination with advanced detection systems this custom-made pipetting robot has the potential to become a valuable tool in future monitoring strategies for drinking and surface water. PMID:28622373

A versatile and low-cost open source pipetting robot for automation of toxicological and ecotoxicological bioassays.

PubMed

Steffens, Sebastian; Nüßer, Leonie; Seiler, Thomas-Benjamin; Ruchter, Nadine; Schumann, Mark; Döring, Ricarda; Cofalla, Catrina; Ostfeld, Avi; Salomons, Elad; Schüttrumpf, Holger; Hollert, Henner; Brinkmann, Markus

2017-01-01

In the past decades, bioassays and whole-organism bioassay have become important tools not only in compliance testing of industrial chemicals and plant protection products, but also in the monitoring of environmental quality. With few exceptions, such test systems are discontinuous. They require exposure of the biological test material in small units, such as multiwell plates, during prolonged incubation periods, and do not allow online read-outs. It is mostly due to these shortcomings that applications in continuous monitoring of, e.g., drinking or surface water quality are largely missing. We propose the use of pipetting robots that can be used to automatically exchange samples in multiwell plates with fresh samples in a semi-static manner, as a potential solution to overcome these limitations. In this study, we developed a simple and low-cost, versatile pipetting robot constructed partly using open-source hardware that has a small footprint and can be used for online monitoring of water quality by means of an automated whole-organism bioassay. We tested its precision in automated 2-fold dilution series and used it for exposure of zebrafish embryos (Danio rerio)-a common model species in ecotoxicology-to cadmium chloride and permethrin. We found that, compared to conventional static or semi-static exposure scenarios, effects of the two chemicals in zebrafish embryos generally occurred at lower concentrations, and analytically verified that the increased frequency of media exchange resulted in a greater availability of the chemical. In combination with advanced detection systems this custom-made pipetting robot has the potential to become a valuable tool in future monitoring strategies for drinking and surface water.

A novel bioassay to evaluate Beauveria bassiana strain NI8 and the insect growth regulator, novaluron, against Lygus lineolaris on a non-autoclaved solid artificial diet

USDA-ARS?s Scientific Manuscript database

Detailed life-tables studies or more quantitative estimates of the impact of control agents on TPB life history require a bioassay option to study the impact of prolonged exposure for weeks following contact with the control agent. This is difficult with plant tissue that must be routinely replaced ...

A CONTROLLED BIOASSAY SYSTEM FOR MEASURING TOXICITY OF HEAVY METALS

EPA Science Inventory

Biological availability of metal micronutrients and metal toxicity are believed to be dependent on metal oxidation state, complexation, and solubility as well as the physicochemical characteristics of the aqueous phase. Basic design criteria for fish bioassays which are capable o...

A Carcinogenicity Bioassay of Isobutyl 2-Cyanoacrylate (IBC) in Fischer-344 Rats

DTIC Science & Technology

1990-01-23

subcutaneous mass M Control 084 24 Oct 85 Pallor, weak, depressed M Low IBC 080 24 Oct 85 Died in cage M High IBC 203 24 Oct 85 Pallor, large M Low IBC intra...abdominal mass 424 25 Oct 85 Weight loss, dehydrated, F High IBC depressed * Animals were sacrificed to conserve tissues in face of imminent death...bioassays due to its low incidence of spontaneous mammary gland and liver cancer . This strain is recommended by the NCI Carcinogenesis Bioassay Program

Bioassaying for ozone with pollen systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feder, W.A.

Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Year-round pollen producion can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilitiesmore » without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.« less

Evaluation of the protein quality of wheat grains (Grizza 155) and eight related products by the dose-response bioassay.

PubMed

Hussein, L; Abbassy, M; Arafa, A; Morcos, S R

1979-12-01

The amino acid analysis revealed that wheat grains, white and dark flour, baladi bread prepared from white or dark flour, bread prepared from formulae enriched with gluten and biscuits are poor in lysine with chemical scores ranging between 20 and 49. The assessment of the protein quality of wheat and related products was done by slope ratio bioassay. Results based on slopes relative to those of reference casein + methionine ranked bread prepared from dark flour and cooked wheat (belila) as the highest in their protein quality, followed by their parent; wheat (RNV = 44). Dietetic bread with gluten had RNV = 20-24; owing to its high protein content (38%), its utilizable protein approached that of good proteins (8%). Very high significant correlation existed between the two measures of response; gain in weight and net increase in body water as response of nitrogen intake.

Impact of application site on the efficacy of two topically-applied insecticides to Culex quinquefasciatus Say

USDA-ARS?s Scientific Manuscript database

Ultra-low volume and low volume insecticide treatments commonly used to control mosquito populations were evaluated for efficacy against Culex quinquefasciatus using a topical bioassay technique. Traditional topical bioassays focus pesticide application to the mesothoracic pleural area. Although, in...

A lab-in-a-droplet bioassay strategy for centrifugal microfluidics with density difference pumping, power to disc and bidirectional flow control.

PubMed

Wang, Guanghui; Ho, Ho-Pui; Chen, Qiulan; Yang, Alice Kar-Lai; Kwok, Ho-Chin; Wu, Shu-Yuen; Kong, Siu-Kai; Kwan, Yiu-Wa; Zhang, Xuping

2013-09-21

In this paper, we present a lab-in-a-droplet bioassay strategy for a centrifugal microfluidics or lab-on-a-disc (LOAD) platform with three important advancements including density difference pumping, power to disc and bidirectional flow control. First, with the water based bioassay droplets trapped in a micro-channel filled with mineral oil, centrifugal force due to the density difference between the water and oil phases actuates droplet movement while the oil based medium remains stationary. Second, electricity is coupled to the rotating disc through a split-core transformer, thus enabling on-chip real-time heating in selected areas as desired and wireless programmable functionality. Third, an inertial mechanical structure is proposed to achieve bidirectional flow control within the spinning disc. The droplets can move back and forth between two heaters upon changing the rotational speed. Our platform is an essential and versatile solution for bioassays such as those involving DNA amplification, where localized temperature cycling is required. Finally, without the loss of generality, we demonstrate the functionality of our platform by performing real-time polymerase chain reaction (RT-PCR) in a linear microchannel made with PTFE (Teflon) micro-tubing.

The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control.

PubMed

Oxborough, Richard M; N'Guessan, Raphael; Jones, Rebecca; Kitau, Jovin; Ngufor, Corine; Malone, David; Mosha, Franklin W; Rowland, Mark W

2015-03-24

The rapid selection of pyrethroid resistance throughout sub-Saharan Africa is a serious threat to malaria vector control. Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions. Unlike neurotoxic insecticides, chlorfenapyr owes its toxicity to disruption of metabolic pathways in mitochondria that enable cellular respiration. A series of experiments explored whether standard World Health Organization (WHO) guidelines for evaluation of long-lasting insecticidal nets, developed through testing of pyrethroid insecticides, are suitable for evaluation of non-neurotoxic insecticides. The efficacy of WHO recommended cone, cylinder and tunnel tests was compared for pyrethroids and chlorfenapyr. To establish bioassay exposure times predictive of insecticide-treated net (ITN) efficacy in experimental hut trials, standard three-minute bioassays of pyrethroid and chlorfenapyr ITNs were compared with longer exposures. Mosquito behaviour and response to chlorfenapyr ITN in bioassays conducted at night were compared to day and across a range of temperatures representative of highland and lowland transmission. Standard three-minute bioassay of chlorfenapyr produced extremely low levels of mortality compared to pyrethroids. Thirty-minute day-time bioassay produced mortality closer to hut efficacy of chlorfenapyr ITN but still fell short of the WHO threshold. Overnight tunnel test with chlorfenapyr produced 100% mortality and exceeded the WHO threshold of 80%. The endogenous circadian activity rhythm of anophelines results in inactivity by day and raised metabolism and flight activity by night. A model which explains improved toxicity of chlorfenapyr ITN when tested at night, and during the day at higher ambient temperature, is that activation of chlorfenapyr and disruption of respiratory pathways is enhanced when the insect is more metabolically and behaviourally active. Testing according to current WHO guidelines is not suitable for certain types of non-neurotoxic insecticide which, although highly effective in field trials, would be overlooked at the screening stage of evaluation through bioassay. Testing methods must be tailored to the characteristics and mode of action of each insecticide class. The WHO tunnel test on night-active anophelines is the most reliable bioassay for identifying the toxicity of novel insecticides.

Identification of Androgen Receptor Antagonists in Fish Using a Simple Bioassay with the Fathead Minnow Pimephales promelas .

EPA Science Inventory

Considerable effort has been expended on the development of bioassays to detect chemicals that affect endocrine function controlled by the vertebrate hypothalamic-pituitary-gonadal (HPG) axis via different mechanisms/modes of action (MOA). Antagonism of the androgen receptor (AR)...

The 10th Annual Bioassays and Bioanalytical Method Development Conference.

PubMed

Ma, Mark; Tudan, Christopher; Koltchev, Dolly

2015-01-01

The 10th Annual Bioassays and Bioanalytical Method Development Conference was hosted in Boston, MA, USA on 20-22 October 2014. This meeting brought together scientists from the biopharmaceutical and life sciences industries, the regulatory agency and academia to share and discuss current trends in cell-based assays and bioanalysis, challenges and ideas for the future of the bioassays and bioanalytical method development. The experiences associated with new and innovative technologies were evaluated as well as their impact on the current bioassays methodologies and bioanalysis workflow, including quality, feasibility, outsourcing strategies and challenges, productivity and compliance. Several presentations were also provided by members of the US FDA, sharing both scientific and regulatory paradigms including a most recent update on the position of the FDA with specific aspects of the draft Bioanalytical Method Validation guidance following its review of the industry's responses. The meeting was jointly coincided with the 15th Annual Immunogenicity for Biotherapeutics meeting, allowing for attendees to also familiarize themselves with new and emerging approaches to overcome the effect of immunogenicity, in addition to investigative strategies.

Bivalve embryo bioassay to assess the potential toxicity of dredged material before dumping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quiniou, F.

1995-12-31

Dredged harbor sediments frequently contain a wide spectrum of contaminants in addition to a significant percentage of organic matter. Also, dredging and dumping activities into sea water, of these highly contaminated soil may induce a harmful effect on the environment. In France, in accordance with Oslo convention guidelines, a working group on dredging activities and environment (GEODE) created since 1991 decided to set up a pilot research program to assess the intrinsic toxicity of four harbor sludges. Intrinsic toxicity of harbor muds were tested by solid phase (whole sediment) and aqueous extract bioassays (sea water elutriates) using the sublethal toxicitymore » test bivalve embryo bioassay (Crassostrea gigas). Elutriates enable them to detect the toxicity of contaminants which may be released in the soluble form into the water column during dredging operations. While, whole sediment integrate the synergistic effects of all the contaminants (hydrophilic and hydrophobic) including pore water. Bioassays results, correlated to chemical analysis, are compared to contaminant levels determined by French working group GEODE and Canadian sediment quality criteria.« less

Effect-directed analysis supporting monitoring of aquatic environments--An in-depth overview.

PubMed

Brack, Werner; Ait-Aissa, Selim; Burgess, Robert M; Busch, Wibke; Creusot, Nicolas; Di Paolo, Carolina; Escher, Beate I; Mark Hewitt, L; Hilscherova, Klara; Hollender, Juliane; Hollert, Henner; Jonker, Willem; Kool, Jeroen; Lamoree, Marja; Muschket, Matthias; Neumann, Steffen; Rostkowski, Pawel; Ruttkies, Christoph; Schollee, Jennifer; Schymanski, Emma L; Schulze, Tobias; Seiler, Thomas-Benjamin; Tindall, Andrew J; De Aragão Umbuzeiro, Gisela; Vrana, Branislav; Krauss, Martin

2016-02-15

Aquatic environments are often contaminated with complex mixtures of chemicals that may pose a risk to ecosystems and human health. This contamination cannot be addressed with target analysis alone but tools are required to reduce this complexity and identify those chemicals that might cause adverse effects. Effect-directed analysis (EDA) is designed to meet this challenge and faces increasing interest in water and sediment quality monitoring. Thus, the present paper summarizes current experience with the EDA approach and the tools required, and provides practical advice on their application. The paper highlights the need for proper problem formulation and gives general advice for study design. As the EDA approach is directed by toxicity, basic principles for the selection of bioassays are given as well as a comprehensive compilation of appropriate assays, including their strengths and weaknesses. A specific focus is given to strategies for sampling, extraction and bioassay dosing since they strongly impact prioritization of toxicants in EDA. Reduction of sample complexity mainly relies on fractionation procedures, which are discussed in this paper, including quality assurance and quality control. Automated combinations of fractionation, biotesting and chemical analysis using so-called hyphenated tools can enhance the throughput and might reduce the risk of artifacts in laboratory work. The key to determining the chemical structures causing effects is analytical toxicant identification. The latest approaches, tools, software and databases for target-, suspect and non-target screening as well as unknown identification are discussed together with analytical and toxicological confirmation approaches. A better understanding of optimal use and combination of EDA tools will help to design efficient and successful toxicant identification studies in the context of quality monitoring in multiply stressed environments. Copyright © 2015 Elsevier B.V. All rights reserved.

Environmental Quality Research: Fish and Aufwuchs Bioassay

DTIC Science & Technology

1977-11-01

WSF) of JP-8 and the solution was renewed each day. Acute toxicity as assessed by the 96-hr LC 50 values was not significantly different over the pH...The 96-hr LC 50 of hydrazine to three-spine sticklebacks was 3.4 mg/i (nominal initial concentration) using 24 hr solution renewal, but the estimated...34spill," i.e., static bioassay with no hydrazine renewal, the 96-hr LC 50 to sticklebacks was 6.6 mg/k (95% confidence limits of 5.0 to 8.8 mg/k) based

Ovipositional response of threeHeliothis species (Lepidoptera: Noctuidae) to allelochemicals from cultivated and wild host plants.

PubMed

Mitchell, E R; Tingle, P C; Heath, R R

1990-06-01

The role of plant allelochemicals on the oviposition behavior ofHeliothis virescens (F.),H. subflexa (Guenee), andH. zea (Boddie) was investigated in the laboratory using a "choice" bioassay system. Fresh young leaves of tobacco,Desmodium tortuosum (Swartz) de Candolle, groundcherry (Physalis angulata L.), and cotton (Gossypium hirsutum L.) squares (flower buds) were washed in methylene chloride or methanol, concentrated to 1 g equivalent of washed material, and applied to a cloth oviposition substrate. Each of the extracts-including groundcherry, a nonhost-stimulated oviposition byH. virescens. H. subflexa were stimulated to oviposit by groundcherry extract, its normal host, and extract from cotton squares, a nonhost. None of the extracts stimulated oviposition byH. zea, although all except groundcherry were from reported hosts. The sensitivity of the bioassay was confirmed by givingH. virescens andH. subflexa an opportunity to choose between extracts that showed stimulant qualities when tested independently versus only solvent-treated controls. In these tests, tobacco showed the highest level of stimulant activity forH. virescens; groundcherry exhibited the highest level of stimulation forH. subflexa.

A rapid bioassay for detecting saxitoxins using a Daphnia acute toxicity test.

PubMed

Ferrão-Filho, Aloysio da S; Soares, Maria Carolina S; de Magalhães, Valéria Freitas; Azevedo, Sandra M F O

2010-06-01

Bioassays using Daphnia pulex and Moina micrura were designed to detect cyanobacterial neurotoxins in raw water samples. Phytoplankton and cyanotoxins from seston were analyzed during 15 months in a eutrophic reservoir. Effective time to immobilize 50% of the exposed individuals (ET50) was adopted as the endpoint. Paralysis of swimming movements was observed between approximately 0.5-3 h of exposure to lake water containing toxic cyanobacteria, followed by an almost complete recovery of the swimming activity within 24 h after being placed in control water. The same effects were observed in bioassays with a saxitoxin-producer strain of Cylindrospermopsis raciborskii isolated from the reservoir. Regression analysis showed significant relationships between ET50 vs. cell density, biomass and saxitoxins content, suggesting that the paralysis of Daphnia in lake water samples was caused by saxitoxins found in C. raciborskii. Daphnia bioassay was found to be a sensitive method for detecting fast-acting neurotoxins in natural samples, with important advantages over mouse bioassays. Copyright 2010 Elsevier Ltd. All rights reserved.

Real-time PCR for the early detection and quantification of Coxiella burnetii as an alternative to the murine bioassay.

PubMed

Howe, Gerald B; Loveless, Bonnie M; Norwood, David; Craw, Philip; Waag, David; England, Marilyn; Lowe, John R; Courtney, Bernard C; Pitt, M Louise; Kulesh, David A

2009-01-01

Real-time PCR was used to analyze archived blood from non-human primates (NHP) and fluid samples originating from a well-controlled Q fever vaccine efficacy trial. The PCR targets were the IS1111 element and the com1 gene of Coxiella burnetii. Data from that previous study were used to evaluate real-time PCR as an alternative to the use of sero-conversion by mouse bioassay for both quantification and early detection of C. burnetii bacteria. Real-time PCR and the mouse bioassay exhibited no statistical difference in quantifying the number of microorganisms delivered in the aerosol challenge dose. The presence of C. burnetii in peripheral blood of non-human primates was detected by real-time PCR as early after exposure as the mouse bioassay with results available within hours instead of weeks. This study demonstrates that real-time PCR has the ability to replace the mouse bioassay to measure dosage and monitor infection of C. burnetii in a non-human primate model.

High-Throughput Mosquito and Fly Bioassay System for Natural and Artificial Substrates Treated with Residual Insecticides

DTIC Science & Technology

2013-03-01

1989. Evaluation of the cotton fabric model for screening topical mosquito repellents . J Am Mosq Control Assoc 5:73–76. WHO [World Health Organization...institutions, research libraries, and research funders in the common goal of maximizing access to critical research. High-Throughput Mosquito and Fly Bioassay...A. Allan , Todd W. Walker , Christopher J. Geden , Jerome A. Hogsette , and Kenneth J. Linthicum Source: Journal of the American Mosquito Control

A fresh look at road salt: aquatic toxicity and water-quality impacts on local, regional, and national scales.

PubMed

Corsi, Steven R; Graczyk, David J; Geis, Steven W; Booth, Nathaniel L; Richards, Kevin D

2010-10-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30,800 μS/cm (Cl = 11,200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria.

A comparative analysis of resistance testing methods in Aedes albopictus (Diptera: Culicidae) from St. Johns County, Florida

USDA-ARS?s Scientific Manuscript database

Aedes albopictus Skuse (Diptera: Culicidae) was tested for resistance to permethrin, bifenthrin, and malathion using Centers for Disease Control and Prevention (CDC) bottle bioassays and topical toxicology assays on adults and larval bioassays. Eggs were collected from 3 locations across St. Johns C...

Peroral bioassay of nucleopolyhedrosis viruses in larvae of western spruce budworm.

Treesearch

Mauro E. Martignoni; Paul J. Iwai

1981-01-01

The relative virulence of entomopathogenic viruses and the potency of virus preparations for control of destructive insects can be estimated reliably only by means of biological assay in the target species. A simple, yet sensitive peroral bioassay procedure is described for preparations of nucleopolyhedrosis viruses pathogenic for the western spruce budworm, ...

Pesticide toxicity index for freshwater aquatic organisms

USGS Publications Warehouse

Munn, Mark D.; Gilliom, Robert J.

2001-01-01

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 75 of the 83 pesticide compounds measured in NAWQA samples, but with a wide range of bioassays per compound (1 to 65). There were a total of 2,824 bioassays for the 75 compounds, including 287 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a nonlethal response) for freshwater cladocerans, 585 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 1,952 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups.While the PTI does not determine whether water in a sample is toxic, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

Effect-based trigger values for in vitro bioassays: Reading across from existing water quality guideline values.

PubMed

Escher, Beate I; Neale, Peta A; Leusch, Frederic D L

2015-09-15

Cell-based bioassays are becoming increasingly popular in water quality assessment. The new generations of reporter-gene assays are very sensitive and effects are often detected in very clean water types such as drinking water and recycled water. For monitoring applications it is therefore imperative to derive trigger values that differentiate between acceptable and unacceptable effect levels. In this proof-of-concept paper, we propose a statistical method to read directly across from chemical guideline values to trigger values without the need to perform in vitro to in vivo extrapolations. The derivation is based on matching effect concentrations with existing chemical guideline values and filtering out appropriate chemicals that are responsive in the given bioassays at concentrations in the range of the guideline values. To account for the mixture effects of many chemicals acting together in a complex water sample, we propose bioanalytical equivalents that integrate the effects of groups of chemicals with the same mode of action that act in a concentration-additive manner. Statistical distribution methods are proposed to derive a specific effect-based trigger bioanalytical equivalent concentration (EBT-BEQ) for each bioassay of environmental interest that targets receptor-mediated toxicity. Even bioassays that are indicative of the same mode of action have slightly different numeric trigger values due to differences in their inherent sensitivity. The algorithm was applied to 18 cell-based bioassays and 11 provisional effect-based trigger bioanalytical equivalents were derived as an illustrative example using the 349 chemical guideline values protective for human health of the Australian Guidelines for Water Recycling. We illustrate the applicability using the example of a diverse set of water samples including recycled water. Most recycled water samples were compliant with the proposed triggers while wastewater effluent would not have been compliant with a few. The approach is readily adaptable to any water type and guideline or regulatory framework and can be expanded from the protection goal of human health to environmental protection targets. While this work constitutes a proof of principle, the applicability remains limited at present due to insufficient experimental bioassay data on individual regulated chemicals and the derived effect-based trigger values are of course only provisional. Once the experimental database is expanded and made more robust, the proposed effect-based trigger values may provide guidance in a regulatory context. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioassay for estimating the biogenic methane-generating potential of coal samples

USGS Publications Warehouse

Jones, Elizabeth J.P.; Voytek, Mary A.; Warwick, Peter D.; Corum, Margo D.; Cohn, Alexander G.; Bunnell, Joseph E.; Clark, Arthur C.; Orem, William H.

2008-01-01

Generation of secondary biogenic methane in coal beds is likely controlled by a combination of factors such as the bioavailability of coal carbon, the presence of a microbial community to convert coal carbon to methane, and an environment supporting microbial growth and methanogenesis. A set of treatments and controls was developed to bioassay the bioavailability of coal for conversion to methane under defined laboratory conditions. Treatments included adding a well-characterized consortium of bacteria and methanogens (enriched from modern wetland sediments) and providing conditions to support endemic microbial activity. The contribution of desorbed methane in the bioassays was determined in treatments with bromoethane sulfonic acid, an inhibitor of microbial methanogenesis. The bioassay compared 16 subbituminous coal samples collected from beds in Texas (TX), Wyoming (WY), and Alaska (AK), and two bituminous coal samples from Pennsylvania (PA). New biogenic methane was observed in several samples of subbituminous coal with the microbial consortium added, but endemic activity was less commonly observed. The highest methane generation [80 µmol methane/g coal (56 scf/ton or 1.75 cm3/g)] was from a south TX coal sample that was collected from a non-gas-producing well. Subbituminous coals from the Powder River Basin, WY and North Slope Borough, AK contained more sorbed (original) methane than the TX coal sample and generated 0–23 µmol/g (up to 16 scf/ton or 0.5 cm3/g) new biogenic methane in the bioassay. Standard indicators of thermal maturity such as burial depth, nitrogen content, and calorific value did not explain differences in biogenic methane among subbituminous coal samples. No original methane was observed in two bituminous samples from PA, nor was any new methane generated in bioassays of these samples. The bioassay offers a new tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the mechanisms involved in this economically important activity.

Effect of disinfection upon dissolved organic carbon (DOC) in wastewater: bacterial bioassays.

PubMed

Arana, I; Santorum, P; Muela, A; Barcina, I

2000-08-01

Quantitative and qualitative changes in organic matter content of wastewater effluents attributable to chlorination and ozonation have been analysed using bioassays as well as organic carbon direct measures. Bioassays were carried out using the bacterial populations of wastewater and two Escherichia coli strains as test micro-organisms. Our results indicate that pure strains present some advantages over indigenous bacteria. Although wastewater bacterial populations are better adapted to growth in wastewater, E. coli strains are more sensitive to changes in dissolved organic carbon (DOC) content. Moreover, the use of pure cultures allows estimation of the portion of DOC which can be converted in cell biomass, the assimilable organic carbon (AOC). Finally, the results obtained using prototrophic and the auxotrophic strains of E. coli suggested that ozonation alters the amino acid composition of wastewater while chlorination does not change the quantity nor the quality of the DOC present in effluents.

[Quality evaluation of rhubarb dispensing granules based on multi-component simultaneous quantitative analysis and bioassay].

PubMed

Tan, Peng; Zhang, Hai-Zhu; Zhang, Ding-Kun; Wu, Shan-Na; Niu, Ming; Wang, Jia-Bo; Xiao, Xiao-He

2017-07-01

This study attempts to evaluate the quality of Chinese formula granules by combined use of multi-component simultaneous quantitative analysis and bioassay. The rhubarb dispensing granules were used as the model drug for demonstrative study. The ultra-high performance liquid chromatography (UPLC) method was adopted for simultaneously quantitative determination of the 10 anthraquinone derivatives (such as aloe emodin-8-O-β-D-glucoside) in rhubarb dispensing granules; purgative biopotency of different batches of rhubarb dispensing granules was determined based on compound diphenoxylate tablets-induced mouse constipation model; blood activating biopotency of different batches of rhubarb dispensing granules was determined based on in vitro rat antiplatelet aggregation model; SPSS 22.0 statistical software was used for correlation analysis between 10 anthraquinone derivatives and purgative biopotency, blood activating biopotency. The results of multi-components simultaneous quantitative analysisshowed that there was a great difference in chemical characterizationand certain differences inpurgative biopotency and blood activating biopotency among 10 batches of rhubarb dispensing granules. The correlation analysis showed that the intensity of purgative biopotency was significantly correlated with the content of conjugated anthraquinone glycosides (P<0.01), and the intensity of blood activating biopotency was significantly correlated with the content of free anthraquinone (P<0.01). In summary, the combined use of multi-component simultaneous quantitative analysis and bioassay can achieve objective quantification and more comprehensive reflection on overall quality difference among different batches of rhubarb dispensing granules. Copyright© by the Chinese Pharmaceutical Association.

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.

PubMed

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.

Paper-based chromatic toxicity bioassay by analysis of bacterial ferricyanide reduction.

PubMed

Pujol-Vila, F; Vigués, N; Guerrero-Navarro, A; Jiménez, S; Gómez, D; Fernández, M; Bori, J; Vallès, B; Riva, M C; Muñoz-Berbel, X; Mas, J

2016-03-03

Water quality assessment requires a continuous and strict analysis of samples to guarantee compliance with established standards. Nowadays, the increasing number of pollutants and their synergistic effects lead to the development general toxicity bioassays capable to analyse water pollution as a whole. Current general toxicity methods, e.g. Microtox(®), rely on long operation protocols, the use of complex and expensive instrumentation and sample pre-treatment, which should be transported to the laboratory for analysis. These requirements delay sample analysis and hence, the response to avoid an environmental catastrophe. In an attempt to solve it, a fast (15 min) and low-cost toxicity bioassay based on the chromatic changes associated to bacterial ferricyanide reduction is here presented. E. coli cells (used as model bacteria) were stably trapped on low-cost paper matrices (cellulose-based paper discs, PDs) and remained viable for long times (1 month at -20 °C). Apart from bacterial carrier, paper matrices also acted as a fluidic element, allowing fluid management without the need of external pumps. Bioassay evaluation was performed using copper as model toxic agent. Chromatic changes associated to bacterial ferricyanide reduction were determined by three different transduction methods, i.e. (i) optical reflectometry (as reference method), (ii) image analysis and (iii) visual inspection. In all cases, bioassay results (in terms of half maximal effective concentrations, EC50) were in agreement with already reported data, confirming the good performance of the bioassay. The validation of the bioassay was performed by analysis of real samples from natural sources, which were analysed and compared with a reference method (i.e. Microtox). Obtained results showed agreement for about 70% of toxic samples and 80% of non-toxic samples, which may validate the use of this simple and quick protocol in the determination of general toxicity. The minimum instrumentation requirements and the simplicity of the bioassay open the possibility of in-situ water toxicity assessment with a fast and low-cost protocol. Copyright © 2016 Elsevier B.V. All rights reserved.

Overview of results from the WaterTox intercalibration and environmental testing phase II program: part 2, ecotoxicological evaluation of drinking water supplies.

PubMed

Diaz-Baez, M C; Sánchez, W A; Dutka, B J; Ronco, A; Castillo, G; Pica-Granados, Y; Castillo, L E; Ridal, J; Arkhipchuk, V; Srivastava, R C

2002-01-01

Because of rapid population growth, industrial development, and intensified agricultural production increasing amounts of chemicals are being released into the environment, polluting receiving water bodies around the world. Given the potential health risk associated with the presence of toxicants in water sources used for drinking yet the scarcity of available data, there is a need to evaluate these waters and develop strategies to reduce and prevent their contamination. The present study examined the applicability of a battery of simple, inexpensive bioassays in environmental management and the relevance of the test results in establishing the toxicological quality of water sources and drinking water within the framework of the eight-country WaterTox Network, sponsored by the International Development Research Centre, Ottawa, Canada. Seventy-six samples were collected from surface and groundwater sources and seven samples from drinking water treatment plants. Each sample was tested with a core battery of bioassays (Daphnia magna, Hydra attenuata, and Lactuca sativa root inhibition tests) and a limited set of physical and chemical parameters. In addition, three labs included the Selenastrum capricornutum test. When no toxic effects were found with the battery, samples were concentrated 10x using a solid-phase extraction (SPE) procedure. Nonconcentrated natural water samples produced a toxic response in 24% of cases with all three core bioassays. When all bioassays are considered, the percentage of raw samples showing toxicity with at least one bioassay increased to 60%. Of seven treated drinkingwater samples, four showed toxicity with at least one bioassay, raising the possibility that treatment processes in these instances were unable to remove toxic contaminants. The Daphnia magna and Hydra attenuata tests indicated a high level of sensitivity overall. Although only three of the eight countries used S. capricornutum, it proved to be an efficient and reliable bioassay for toxicity assessment. Copyright 2002 Wiley Periodicals, Inc.

Design and Proof-of-Concept Use of a Circular PMMA Platform with 16-Well Sample Capacity for Microwave-Accelerated Bioassays.

PubMed

Mohammed, Muzaffer; Aslan, Kadir

2013-01-01

We demonstrate the design and the proof-of-concept use of a new, circular poly(methyl methacrylate)-based bioassay platform (PMMA platform), which affords for the rapid processing of 16 samples at once. The circular PMMA platform (5 cm in diameter) was coated with a silver nanoparticle film to accelerate the bioassay steps by microwave heating. A model colorimetric bioassay for biotinylated albumin (using streptavidin-labeled horse radish peroxidase) was performed on the PMMA platform coated with and without silver nanoparticles (a control experiment), and at room temperature and using microwave heating. It was shown that the simulated temperature profile of the PMMA platform during microwave heating were comparable to the real-time temperature profile during actual microwave heating of the constructed PMMA platform in a commercial microwave oven. The model colorimetric bioassay for biotinylated albumin was successfully completed in ~2 min (total assay time) using microwave heating, as compared to 90 min at room temperature (total assay time), which indicates a ~45-fold decrease in assay time. Our PMMA platform design afforded for significant reduction in non-specific interactions and low background signal as compared to non-silvered PMMA surfaces when employed in a microwave-accelerated bioassay carried out in a conventional microwave cavity.

A Fresh Look at Road Salt: Aquatic Toxicity and Water-Quality Impacts on Local, Regional, and National Scales

PubMed Central

2010-01-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30 800 μS/cm (Cl = 11 200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria. PMID:20806974

A fresh look at road salt: Aquatic toxicity and water-quality impacts on local, regional, and national scales

USGS Publications Warehouse

Corsi, S.R.; Graczyk, D.J.; Geis, S.W.; Booth, N.L.; Richards, K.D.

2010-01-01

A new perspective on the severity of aquatic toxicity impact of road salt was gained by a focused research effort directed at winter runoff periods. Dramatic impacts were observed on local, regional, and national scales. Locally, samples from 7 of 13 Milwaukee, Wisconsin area streams exhibited toxicity in Ceriodaphnia dubia and Pimephales promelas bioassays during road-salt runoff. Another Milwaukee stream was sampled from 1996 to 2008 with 72% of 37 samples exhibiting toxicity in chronic bioassays and 43% in acute bioassays. The maximum chloride concentration was 7730 mg/L. Regionally, in southeast Wisconsin, continuous specific conductance was monitored as a chloride surrogate in 11 watersheds with urban land use from 6.0 to 100%. Elevated specific conductance was observed between November and April at all sites, with continuing effects between May and October at sites with the highest specific conductance. Specific conductance was measured as high as 30 800 ??S/cm (Cl = 11 200 mg/L). Chloride concentrations exceeded U.S. Environmental Protection Agency (USEPA) acute (860 mg/L) and chronic (230 mg/L) water-quality criteria at 55 and 100% of monitored sites, respectively. Nationally, U.S. Geological Survey historical data were examined for 13 northern and 4 southern metropolitan areas. Chloride concentrations exceeded USEPA water-quality criteria at 55% (chronic) and 25% (acute) of the 168 monitoring locations in northern metropolitan areas from November to April. Only 16% (chronic) and 1% (acute) of sites exceeded criteria from May to October. At southern sites, very few samples exceeded chronic water-quality criteria, and no samples exceeded acute criteria. ?? 2010 American Chemical Society.

Laboratory Screening and Field Bioassays of Insecticides for Controlling the Balsam Woolly Adelgid in Southen Appalachia

Treesearch

F.L. Hastings; P.J. Barry; I.R. Ragenovich

1979-01-01

Two concentrations of 13 insecticides and 3 fatty acids were screened in the laboratory against the balsam woolly adelgid (Adelges piceae (Ratz.)). Efficacy was judged on the percentage of dead adults and the number of living crawlers 24 hours after application. The top candidate materials, including lindane, were field bioassayed. Permethrin (Pounce or Ambush),...

In vitro bioassay for reactive toxicity towards proteins implemented for water quality monitoring.

PubMed

Tang, Janet Y M; Glenn, Eva; Thoen, Hanne; Escher, Beate I

2012-03-01

Reactive organic chemicals comprise a large number of compounds with a variety of reactive moieties. While most assays for reactive toxicity focus on DNA damage, reactivity towards proteins can also lead to irreparable damage, but reactivity towards proteins is typically not included in any test battery for water quality assessment. Glutathione (GSH) is a small tripeptide whose cysteine moiety can serve as a model for nucleophilic sites on proteins. GSH is also an important indicator of detoxification processes and the redox status of cells and due to its protective role, depletion of GSH ultimately leads to adverse effects. A bioassay based on genetically modified Escherichia coli strains was used to quantify the specific reactivity towards the protein-like biological nucelophile GSH. The significance of GSH for detoxification was assessed by comparing the growth inhibition induced by reference chemicals or water samples in a GSH-deficient strain to its fully functional parent strain. The GSH deficient strain showed the same sensitivity as the GSH proficient strain to non-reactive and DNA damaging chemicals, but was more sensitive to chemicals that attack cysteine in proteins. The difference in effect concentrations for 50% inhibition of growth assessed as biomass increase (EC(50)) between the two strains indicates the relevance of GSH conjugation as a detoxification step as well as direct reactivity with cysteine-containing proteins. Seven reference compounds serving as positive and negative controls were investigated. The E. coli strain that lacks GSH was four times more sensitive towards the positive control Sea-Nine, while negative controls benzo[a]pyrene, 2-aminoanthracene, phenol, t-butylhydroquinone, methyl methane sulfonate and 4-nitroquinoline oxide showed equal effect concentrations in both strains. Water samples collected across an indirect potable reuse scheme representing the complete water cycle from sewage to drinking water in South East Queensland, Australia were used to evaluate the applicability of the E. coli assay for reactive toxicity in water samples. While the EC(50) values of the GSH+ strain showed similar trends as in other biological endpoints over the various treatment chains, the specific response indicative of protein damage was only observed in samples that had undergone chlorination as a disinfection process. High natural organic matter or other matrix components disturbed the bioassay so much that we recommend it for future routine testing only in tertiary treated water or drinking water. This journal is © The Royal Society of Chemistry 2012

Real-Time Continuous Identification of Greenhouse Plant Pathogens Based on Recyclable Microfluidic Bioassay System.

PubMed

Qu, Xiangmeng; Li, Min; Zhang, Hongbo; Lin, Chenglie; Wang, Fei; Xiao, Mingshu; Zhou, Yi; Shi, Jiye; Aldalbahi, Ali; Pei, Hao; Chen, Hong; Li, Li

2017-09-20

The development of a real-time continuous analytical platform for the pathogen detection is of great scientific importance for achieving better disease control and prevention. In this work, we report a rapid and recyclable microfluidic bioassay system constructed from oligonucleotide arrays for selective and sensitive continuous identification of DNA targets of fungal pathogens. We employ the thermal denaturation method to effectively regenerate the oligonucleotide arrays for multiple sample detection, which could considerably reduce the screening effort and costs. The combination of thermal denaturation and laser-induced fluorescence detection technique enables real-time continuous identification of multiple samples (<10 min per sample). As a proof of concept, we have demonstrated that two DNA targets of fungal pathogens (Botrytis cinerea and Didymella bryoniae) can be sequentially analyzed using our rapid microfluidic bioassay system, which provides a new paradigm in the design of microfluidic bioassay system and will be valuable for chemical and biomedical analysis.

Rainfastness of insecticides used to control Japanese beetle in blueberries.

PubMed

Hulbert, Daniel; Reeb, Pablo; Isaacs, Rufus; Vandervoort, Christine; Erhardt, Susan; Wise, John C

2012-10-01

Field-based bioassays were used to determine the relative impact of rainfall on the relative toxicity of four insecticides, phosmet, carbaryl, zeta-cypermethrin, or imidacloprid, from different chemical classes on adult Japanese beetles, Popillia japonica Newman, in highbush blueberries, Vaccinium corymbosum L. Bioassays were set up 24 h after spraying occurred and Japanese beetle condition was scored as alive, knockdown or immobile 1, 24, and 48 h after bioassay setup. All insecticides were significantly more toxic than the untreated control and zeta-cypermethrin consistently had the greatest toxic effect against the Japanese beetles. All insecticides experienced a decrease in efficacy after simulated rainfall onto treated blueberry shoots, although the efficacy of zeta-cypermethrin was the least affected by rainfall. This study will help blueberry growers make informed decisions on when reapplications of insecticides are needed in the field with the aim of improving integrated pest management (IPM).

Flow-through bioassay for measuring bioaccumulation of toxic substances from sediment

USGS Publications Warehouse

Mac, Michael J.; Edsall, Carol C.; Hesselberg, Robert J.; Sayers, Richard E.

1984-01-01

Over 10 million cubic meters of sediment are dredged annually from Great Lakes waterways. Because much of this material is taken from harbors, connecting channels, and other nearshore areas that often are contaminated with toxic substances, the sediments proposed for dredging need to be evaluated for the presence of bioavailable contaminants and the potential for toxicity to the biota. Sound decisions on the appropriate disposal of the dredged material can be made only after such an evaluation. Presently, no standardized procedure exists for evaluating dredged material in freshwater systems although current criteria for discharge of dredged material into marine water have been developed (USEPA/CE 1977). In the ocean discharge guideline, it is recommended that bioassays be conducted on liquid, solid, and suspended particulate phases of dredged material. because it appears that the solid phase has the greatest potential for environmental damage and because measurement of bioaccumulation must be made to evaluate sediments for disposal (USEPA/CE 1977, Seeyle and Mac 1983), we developed a bioassay for testing the solid phase of dredged material that measures the survival of organisms and, perhaps more important, the bioaccumulation of toxic substances by aquatic organisms from naturally contaminated sediments (Peddicord et al. 1980; Rubinstein et al. 1980, 1983; Seeyle st al. 1982), several have used testing methods that result in unacceptable mortality to control organisms (Bahnick et al. 1981, Prater et al. 1983). Our bioassay is intended to estimate the potential for bioaccumlation of contaminants from sediments that are not acutely toxic to test organisms, but are suspected of containing persistent contaminants. By using test organisms that are not highly susceptible to toxic compounds, the bioaccumulation test allows estimation of the potential food-chain accumulation of contaminants that may occur in local biota from surficial sediments. In practice, bioaccumulation observed in this bioassay by organisms exposed to test sediments (sediments to be dredged) would be compared to bioaccumulation observed from sediments collected from a reference site (e.g. a disposal site or open lake), and also from control sediments (relatively clean sediment). Decisions could then be based on a comparison of results between tests and reference sediments to determine if disposal would cause dehydration to the habitat, and between reference and control sediment to determine if even the reference material is seriously contaminated. Although the test is not intended to be a toxicity test per se, use of test, reference, and control sediments enables interpretation of any mortality of organisms that may occur during the bioassays. High mortality in bioassays with test or reference sediment would indicate acute toxicity of sediments in the project area. However if high mortality occurs in all three sediments, it can be assumed that the organisms were not in a healthy state at the time of testing. We describe the results of 10-day sediment bioassays in which both mortality and bioaccumulation were measured in four aquatic organisms. We exposed two infaunal organisms and two species of fish to test and control sediments in the laboratory.

Kinetic microplate bioassays for relative potency of antibiotics improved by partial Least Square (PLS) regression.

PubMed

Francisco, Fabiane Lacerda; Saviano, Alessandro Morais; Almeida, Túlia de Souza Botelho; Lourenço, Felipe Rebello

2016-05-01

Microbiological assays are widely used to estimate the relative potencies of antibiotics in order to guarantee the efficacy, safety, and quality of drug products. Despite of the advantages of turbidimetric bioassays when compared to other methods, it has limitations concerning the linearity and range of the dose-response curve determination. Here, we proposed to use partial least squares (PLS) regression to solve these limitations and to improve the prediction of relative potencies of antibiotics. Kinetic-reading microplate turbidimetric bioassays for apramacyin and vancomycin were performed using Escherichia coli (ATCC 8739) and Bacillus subtilis (ATCC 6633), respectively. Microbial growths were measured as absorbance up to 180 and 300min for apramycin and vancomycin turbidimetric bioassays, respectively. Conventional dose-response curves (absorbances or area under the microbial growth curve vs. log of antibiotic concentration) showed significant regression, however there were significant deviation of linearity. Thus, they could not be used for relative potency estimations. PLS regression allowed us to construct a predictive model for estimating the relative potencies of apramycin and vancomycin without over-fitting and it improved the linear range of turbidimetric bioassay. In addition, PLS regression provided predictions of relative potencies equivalent to those obtained from agar diffusion official methods. Therefore, we conclude that PLS regression may be used to estimate the relative potencies of antibiotics with significant advantages when compared to conventional dose-response curve determination. Copyright © 2016 Elsevier B.V. All rights reserved.

Activities of Jatropha curcas phorbol esters in various bioassays.

PubMed

Devappa, Rakshit K; Rajesh, Sanjay K; Kumar, Vikas; Makkar, Harinder P S; Becker, Klaus

2012-04-01

Jatropha curcas seeds contain 30-35% oil, which can be converted to high quality biodiesel. However, Jatropha oil is toxic, ascribed to the presence of phorbol esters (PEs). In this study, isolated phorbol ester rich fraction (PEEF) was used to evaluate the activity of PEs using three aquatic species based bioassays (snail (Physa fontinalis), brine shrimp (Artemeia salina), daphnia (Daphnia magna)) and microorganisms. In all the bioassays tested, increase in concentration of PEs increased mortality with an EC(50) (48 h) of 0.33, 26.48 and 0.95 mg L(-1) PEs for snail, artemia and daphnia, respectively. The sensitivity of various microorganisms for PEs was also tested. Among the bacterial species tested, Streptococcus pyogenes and Proteus mirabilis were highly susceptible with a minimum inhibitory concentration (MIC) of 215 mg L(-1) PEs; and Pseudomonas putida were also sensitive with MIC of 251 mg L(-1) PEs. Similarly, Fusarium species of fungi exhibited EC(50) of 58 mg L(-1) PEs, while Aspergillus niger and Curvularia lunata had EC(50) of 70 mg L(-1). The snail bioassay was most sensitive with 100% snail mortality at 1 μg of PEs mL(-1). In conclusion, snail bioassay could be used to monitor PEs in Jatropha derived products such as oil, biodiesel, fatty acid distillate, kernel meal, cake, glycerol or for contamination in soil or other environmental matrices. In addition, PEs with molluscicidal/antimicrobial activities could be utilized for agricultural and pharmaceutical applications. Copyright © 2011 Elsevier Inc. All rights reserved.

Effect of restoration thinning on mycorrhizal fungal propagules in a northern Arizona ponderosa pine forest: Preliminary results

Treesearch

Julie E. Korb; Nancy C. Johnson; W. W. Covington

2001-01-01

The inoculum potential for arbuscular mycorrhizal (AM) and ectomycorrhizal (EM) fungi were investigated in thinned and uncut control stands in a northern Arizona ponderosa pine forest. A corn bioassay was used to determine the relative amount of infective propagules of AM fungi, and a ponderosa pine (Pinus ponderosa) bioassay was used to determine the relative amount...

An inventory and evaluation of biological investigations that relate to stream-water quality in the upper Illinois River basin of Illinois, Indiana, and Wisconsin

USGS Publications Warehouse

Steffeck, D.W.; Striegl, Robert G.

1989-01-01

Results of studies of the aquatic biology of the upper Illinois River basin provide a historical data source from which inferences can be made about changes in the quality of water in the main stem river and its tributaries. The results of biological investigations that have been conducted throughout the basin since 1900 are summarized and their relevance to stream-water-quality assessment is described, particularly their relevance to the upper Illinois River basin pilot project for the National Water Quality Assessment program. Four general categories of biological investigations were identified: Populations and community structure, chemical concentrations in tissue, organism health, and toxicity measurements. Biological investigations were identified by their location in the basin and by their relevance to each general investigation category. The most abundant literature was in the populations and community structure category. Tissue data were limited to polychlorinated biphenyls, organochlorine pesticides, dioxin, and several metals. The most cited measure of organism health was a condition factor for fish that associates body length with weight or body depth. Toxicity measurements included bioassays and the Ames Tests. The bioassays included several testing methods and test organism. (USGS)

Field evaluation of systemic imidacloprid for the management of avocado thrips and avocado lace bug in California avocado groves.

PubMed

Byrne, Frank J; Humeres, Eduardo C; Urena, Anthony A; Hoddle, Mark S; Morse, Joseph G

2010-10-01

The efficacy of systemic applications of imidacloprid for the management of avocado thrips and avocado lace bug was determined in field trials. Following insecticide treatment by chemigation, leaves of appropriate age for each insect were sampled over a 6 month period and used for bioassays. Imidacloprid residues were measured by ELISA in leaves used for bioassays to determine concentrations of insecticide that were toxic to both pests. The uptake of imidacloprid into treated trees was extremely slow, peaking in the current year's leaf flush at only 8 ng cm(-2) leaf tissue after 15 weeks. Avocado thrips mortality in bioassays with young flush leaves, the preferred feeding substrate for this insect, was minimal, indicating that imidacloprid concentrations were below threshold levels needed for effective control. Residues present in older leaves, which are preferred by the avocado lace bug, were higher than in young flush leaves, and provided good control of this pest. Probit analysis of bioassay data showed that the avocado lace bug (LC(50) = 6.1 ng imidacloprid cm(-2) leaf tissue) was more susceptible to imidacloprid than the avocado thrips (LC(50) = 73 ng imidacloprid cm(-2) leaf tissue). In spite of the slow uptake of imidacloprid into avocado trees, the levels of imidacloprid would be sufficient to control avocado lace bug infestations. In contrast, the slow uptake would be problematic for avocado thrips control because inadequate levels of insecticide accumulate in new flush foliage and would allow avocado thrips populations to build to levels that would subsequently damage developing avocado fruit.

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

PubMed

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

2016-11-01

Key differences in the developmental process of pelagic fish embryos, in comparison to embryos of standard test fish species, present challenges to obtaining sufficient control survival needed to successfully perform traditional toxicity testing bioassays. Many of these challenges relate to the change in buoyancy, from positive to negative, of pelagic fish embryos that occurs just prior to hatch. A novel exposure system, the pelagic embryo-larval exposure chamber (PELEC), has been developed to conduct successful bioassays on the early life stages (ELSs; embryos/larvae) of pelagic fish. Using this unique recirculating upwelling system, it was possible to significantly improve control survival in pelagic fish ELS bioassays compared to commonly used static exposure methods. Results demonstrate that control performance of mahi-mahi (Coryphaena hippurus) embryos in the PELEC system, measured as percent survival after 96-hrs, significantly outperformed agitated static exposure and static exposure systems. Similar significant improvements in 72-hr control survival were obtained with yellowfin tuna (Thunnus albacares). The PELEC system was subsequently used to test the effects of photo-induced toxicity of crude oil to mahi-mahi ELSs over the course of 96-hrs. Results indicate a greater than 9-fold increase in toxicity of Deepwater Horizon (DWH) crude oil during co-exposure to ambient sunlight compared to filtered ambient sunlight, revealing the importance of including natural sunlight in 96-hr DWH crude oil bioassays as well as the PELEC system's potential application in ecotoxicological assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Review of the Application of Body-on-a-Chip for Drug Test and Its Latest Trend of Incorporating Barrier Tissue.

PubMed

Jin, Haoyi; Yu, Yanqiu

2016-10-01

High-quality preclinical bioassay models are essential for drug research and development. We reviewed the emerging body-on-a-chip technology, which serves as a promising model to overcome the limitations of traditional bioassay models, and introduced existing models of body-on-a-chip, their constitutional details, application for drug testing, and individual features of these models. We put special emphasis on the latest trend in this field of incorporating barrier tissue into body-on-a-chip and discussed several remaining challenges of current body-on-a-chip. © 2015 Society for Laboratory Automation and Screening.

A Novel in vitro Bioassay to Explore the Repellent Effects of Compounds Against Mosquito Aedes aegypti (Diptera: Culicidae).

PubMed

Rehman, Junaid U; Tabanca, Nurhayat; Khan, Ikhlas A

2016-01-01

Mosquitoes are vectors for many pathogens resulting in many deaths of humans. Repellents play an important role in reducing mosquito bites and the spread of mosquito-borne diseases. Currently, Klun & Debboun (K & D) and human-arm-based bioassay systems are used to identify repellent properties of compounds, extracts, and essential oils. Risks involved with human-arm-based systems are allergic reactions and limited replicates. We are reporting an in vitro bioassay method “NCNPR repellent bioassay (NCNPR-RB)” that can closely simulate the results of the cloth patch bioassay system used to determine repellency against mosquitoes. The NCNPRRB method uses heat to attract mosquito and edible collagen sheets as an alternate to human skin. Multiple plant compounds with documented repellency were tested. DEET (N,N-diethyl-3-methylbenzamide) was used as a positive control. Treatments were prepared in EtOH and applied in dosages ranging from 0.011–1.5mg/cm2 to a 20-cm2 collagen sheet. The number of mosquitoes commencing to bite per probe was recorded visually for 1 min. The minimum effective dosage (mg/cm2) of compounds: DEET (0.021), carvacrol (0.011), thymol (0.013), undecanoic acid (0.023), thymol methyl ether (0.269), and 2-nonanone (>0.375 mg/cm2) determined in NCNPRRB were similar to those reported in literature using a cloth patch bioassay system. The NCNPR-RB can be used to screen compounds with reasonable reproducibility of the data at a faster rate than the cloth patch bioassay, which involves the use of human subjects.

Biomimetic engineering of a generic cell-on-membrane architecture by microfluidic engraving for on-chip bioassays.

PubMed

Lee, Sang-Wook; Noh, Ji-Yoon; Park, Seung Chul; Chung, Jin-Ho; Lee, Byoungho; Lee, Sin-Doo

2012-05-22

We develop a biomimetic cell-on-membrane architecture in close-volume format which allows the interfacial biocompatibility and the reagent delivery capability for on-chip bioassays. The key concept lies in the microfluidic engraving of lipid membranes together with biological cells on a supported substrate with topographic patterns. The simultaneous engraving process of a different class of fluids is promoted by the front propagation of an air-water interface inside a flow-cell. This highly parallel, microfluidic cell-on-membrane approach opens a door to the natural biocompatibility in mimicking cellular stimuli-response behavior essential for diverse on-chip bioassays that can be precisely controlled in the spatial and temporal manner.

Pesticide toxicity index for freshwater aquatic organisms, 2nd edition

USGS Publications Warehouse

Munn, Mark D.; Gilliom, Robert J.; Moran, Patrick W.; Nowell, Lisa H.

2006-01-01

The U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program is designed to assess current water-quality conditions, changes in water quality over time, and the effects of natural and human factors on water quality for the Nation's streams and ground-water resources. For streams, one of the most difficult parts of the assessment is to link chemical conditions to effects on aquatic biota, particularly for pesticides, which tend to occur in streams as complex mixtures with strong seasonal patterns. A Pesticide Toxicity Index (PTI) was developed that combines pesticide exposure of aquatic biota (measured concentrations of pesticides in stream water) with acute toxicity estimates (standard endpoints from laboratory bioassays) to produce a single index value for a sample or site. The development of the PTI was limited to pesticide compounds routinely measured in NAWQA studies and to toxicity data readily available from existing databases. Qualifying toxicity data were found for one or more types of test organisms for 124 of the 185 pesticide compounds measured in NAWQA samples, but with a wide range of available bioassays per compound (1 to 232). In the databases examined, there were a total of 3,669 bioassays for the 124 compounds, including 398 48-hour EC50 values (concentration at which 50 percent of test organisms exhibit a sublethal response) for freshwater cladocerans, 699 96-hour LC50 values (concentration lethal to 50 percent of test organisms) for freshwater benthic invertebrates, and 2,572 96-hour LC50 values for freshwater fish. The PTI for a particular sample is the sum of toxicity quotients (measured concentration divided by the median toxicity concentration from bioassays) for each detected pesticide, and thus, is based on the concentration addition model of pesticide toxicity. The PTI can be calculated for specific groups of pesticides and for specific taxonomic groups. Although the PTI does not determine whether water in a sample is toxic to aquatic organisms, its values can be used to rank or compare the toxicity of samples or sites on a relative basis for use in further analysis or additional assessments. The PTI approach may be useful as a basis for comparing the potential significance of pesticides in different streams on a common basis, for evaluating relations between pesticide exposure and observed biological conditions, and for prioritizing where further studies are most needed.

Linking sewage pollution and water quality to spatial patterns of Porites lobata growth anomalies in Puako, Hawaii.

PubMed

Yoshioka, Reyn M; Kim, Catherine J S; Tracy, Allison M; Most, Rebecca; Harvell, C Drew

2016-03-15

Sewage pollution threatens the health of coastal populations and ecosystems, including coral reefs. We investigated spatial patterns of sewage pollution in Puako, Hawaii using enterococci concentrations and δ(15)N Ulva fasciata macroalgal bioassays to assess relationships with the coral disease Porites lobata growth anomalies (PGAs). PGA severity and enterococci concentrations were high, spatially variable, and positively related. Bioassay algal δ(15)N showed low sewage pollution at the reef edge while high values of resident algae indicated sewage pollution nearshore. Neither δ(15)N metric predicted PGA measures, though bioassay δ(15)N was negatively related to coral cover. Furthermore, PGA prevalence was much higher than previously recorded in Hawaii and the greater Indo-Pacific, highlighting Puako as an area of concern. Although further work is needed to resolve the relationship between sewage pollution and coral cover and disease, these results implicate sewage pollution as a contributor to diminished reef health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Scrubchem: Building Bioactivity Datasets from Pubchem ...

EPA Pesticide Factsheets

The PubChem Bioassay database is a non-curated public repository with data from 64 sources, including: ChEMBL, BindingDb, DrugBank, EPA Tox21, NIH Molecular Libraries Screening Program, and various other academic, government, and industrial contributors. Methods for extracting this public data into quality datasets, useable for analytical research, presents several big-data challenges for which we have designed manageable solutions. According to our preliminary work, there are approximately 549 million bioactivity values and related meta-data within PubChem that can be mapped to over 10,000 biological targets. However, this data is not ready for use in data-driven research, mainly due to lack of structured annotations.We used a pragmatic approach that provides increasing access to bioactivity values in the PubChem Bioassay database. This included restructuring of individual PubChem Bioassay files into a relational database (ScrubChem). ScrubChem contains all primary PubChem Bioassay data that was: reparsed; error-corrected (when applicable); enriched with additional data links from other NCBI databases; and improved by adding key biological and assay annotations derived from logic-based language processing rules. The utility of ScrubChem and the curation process were illustrated using an example bioactivity dataset for the androgen receptor protein. This initial work serves as a trial ground for establishing the technical framework for accessing, integrating, cu

Efficacy of Chemicals for the Potential Management of the Queensland Fruit Fly Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

PubMed Central

Reynolds, Olivia L.; Osborne, Terrence J.; Barchia, Idris

2017-01-01

This study investigated alternative in-field chemical controls against Bactrocera tryoni (Froggatt). Bioassay 1 tested the mortality of adults exposed to fruit and filter paper dipped in insecticide, and the topical application of insecticide to adults/fruit. Bioassay 2 measured the mortality of adults permitted to oviposit on fruit dipped in insecticide and aged 0, 1, 3, or 5 days, plus the production of offspring. Bioassay 3 tested infested fruit sprayed with insecticide. The field bioassay trialed the mortality of adults exposed to one- and five-day insecticide residues on peaches, and subsequent offspring. Abamectin, alpha-cypermethrin, clothianidin, dimethoate (half-label rate), emamectin benzoate, fenthion (half- and full-label rate), and trichlorfon were the most efficacious in bioassay 1, across 18 tested insecticide treatments. Overall, the LT50 value was lowest for fenthion (full-label rate), clothianidin, and alpha-cypermethrin. Fenthion, emamectin benzoate, and abamectin had the greatest effect on adult mortality and offspring production. Infested fruit treated with acetamiprid, fenthion, and thiacloprid produced no/very few offspring. Alpha-cypermethrin demonstrated good field efficacy against adults (one day post treatment: 97.2% mortality, five day post treatment: 98.8% mortality) and subsequent offspring (100% across one and five day post treatments), comparable to that of fenthion (full-label rate) (100% mortality for offspring and adults across both post treatments). Alpha-cypermethrin is a possible alternative to fenthion against B. tryoni; as a pyrethroid, it may not be desirable if adjunct biological control is imperative. Thiacloprid and Acetamiprid may be useful as a post-harvest treatment. PMID:28486404

Insecticide Resistance Management

DTIC Science & Technology

2013-01-01

been a side effect of insect vector control programs since 1914, and insect disease vectors in over 45 countries are resistant to at least one...the CDC and WHO bioassays can be performed on various insects , the remainder of the guide will focus specifically on how to detect resistance in...mosquito vector populations. For a description of how to develop a bioassay for resistance testing in other groups of insects , refer to the following

Infectivity of porcine circovirus type 2 DNA in semen from experimentally-infected boars

PubMed Central

Madson, Darin M.; Ramamoorthy, Sheela; Kuster, Chris; Pal, Narinder; Meng, Xiang-Jin; Halbur, Patrick G.; Opriessnig, Tanja

2009-01-01

Porcine circovirus type 2 (PCV2) is an economically important pathogen. It has been demonstrated that PCV2 DNA can be detected in boar semen by PCR; however, the biological relevance of this is unknown. The objectives of this study were to determine if semen positive for PCV2 DNA is infectious (1) in a swine bioassay, or (2) when used for artificial insemination. For the first objective, 4-week-old pigs were inoculated intraperitoneally with PCV2 DNA-negative (bioassay-control; n = 3), PCV2a DNA-positive (bioassay-PCV2a; n = 3), or PCV2b DNA-positive (bioassay-PCV2b; n = 3) raw semen, or PCV2 live virus (bioassay-positive; n = 3), respectively. Pigs inoculated with PCV2 DNA-positive semen and PCV2 live virus became viremic and developed anti-PCV2 antibodies indicating that the PCV2 DNA present in semen was infectious. For the second objective, three Landrace gilts were inseminated with PCV2 DNA-negative semen (gilts-controls) from experimentally-infected boars, and six gilts were artificially inseminated with semen positive for PCV2a DNA (gilts-PCV2a; n = 3) or PCV2b DNA (gilts-PCV2b; n = 3). Serum samples collected from the gilts in all groups remained negative for anti-PCV2 antibodies for the duration of the experiment. In addition, fetal serum samples from all 105-day-gestation fetuses were negative for anti-PCV2 antibodies or PCV2 DNA. Under the conditions of this study, PCV2 DNA-positive semen was not infectious when used to artificially inseminate gilts; however, it was demonstrated to be infectious in a swine bioassay model and therefore is a potential means of PCV2 transmission amongst swine herds. PMID:18973743

Integrative assessment of coastal pollution: Development and evaluation of sediment quality criteria from chemical contamination and ecotoxicological data

NASA Astrophysics Data System (ADS)

Bellas, Juan; Nieto, Óscar; Beiras, Ricardo

2011-04-01

Elutriate embryo-larval bioassays with sea-urchins ( Paracentrotus lividus) were conducted concurrently with chemical analyses of sediments and biota as part of an integrative assessment of pollution in highly productive coastal regions. High metal contents and organic compounds in sediments and mussels were found in localised areas from the inner part of the estuaries indicating a clear anthropogenic influence. In particular, average maximum concentrations of 2803 mg Cu/kg dw, 776 mg Pb/kg dw, 2.5 mg Hg/kg dw and 5803 μg ∑ 7PAHs/kg dw were measured in sediments from the most polluted sites. Significant correlations were observed between sediment chemistry and toxicity bioassays. Moreover, the Mantel test revealed a significant correlation ( rM=0.80; p<0.01) between sediment pollutant concentrations and toxicity data profiles. In addition, sediment quality criteria were used to help in the ecological interpretation of sediment chemistry data and to identify pollutants of concern. The toxicity bioassays identified polluted sites and quantified the level of toxicity, providing a cost-effective tool to complement the routine chemical monitoring currently conducted in European coastal waters with ecologically relevant information. This is in line with the recent European legislation that advocates the use of biological tools with the ultimate aim of protecting marine resources from anthropogenic substances that will affect their sensitive early life stages.

Cryopreserved semen in ecotoxicological bioassays: sensitivity and reliability of cryopreserved Sparus aurata spermatozoa.

PubMed

Fabbrocini, Adele; D'Adamo, Raffaele; Del Prete, Francesco; Langellotti, Antonio Luca; Rinna, Francesca; Silvestri, Fausto; Sorrenti, Gerarda; Vitiello, Valentina; Sansone, Giovanni

2012-10-01

The aim of this study was to evaluate the feasibility of using cryopreserved S. aurata semen in spermiotoxicity tests. Cryopreservation is a biotechnology that can provide viable gametes and embryos on demand, rather than only in the spawning season, thus overcoming a limitation that has hindered the use of some species in ecotoxicological bioassays. Firstly, the sperm motility pattern of cryopreserved semen was evaluated after thawing by means of both visual and computer-assisted analyses. Motility parameters in the cryopreserved semen did not change significantly in the first hour after thawing, meaning that they were maintained for long enough to enable their use in spermiotoxicity tests. In the second phase of the research, bioassays were performed, using cadmium as the reference toxicant, in order to evaluate the sensitivity of cryopreserved S. aurata semen to ecotoxicological contamination. The sensitivity of the sperm motility parameters used as endpoints (motility percentages and velocities) proved to be comparable to what has been recorded for the fresh semen of other aquatic species (LOECs from 0.02 to 0.03 mg L(-1)). The test showed good reliability and was found to be rapid and easy to perform, requiring only a small volume of the sample. Moreover, cryopreserved semen is easy to store and transfer and makes it possible to perform bioassays in different sites or at different times with the same batch of semen. The proposed bioassay is therefore a promising starting point for the development of toxicity tests that are increasingly tailored to the needs of ecotoxicology and environmental quality evaluation strategies. Copyright © 2012 Elsevier Inc. All rights reserved.

Collaborative study for the establishment of erythropoietin BRP batch 4.

PubMed

Burns, C; Bristow, A F; Daas, A; Costanzo, A

2015-01-01

The European Pharmacopoeia (Ph. Eur.) Biological Reference Preparation (BRP) for erythropoietin (EPO) is used as a working standard for potency determination of EPO preparations by in vivo bioassay as prescribed in the Ph. Eur. monograph Erythropoietin concentrated solution (1316). The BRP batch 3 was calibrated in 2006 and its stocks are depleted. The European Directorate for the Quality of Medicines & HealthCare (EDQM) thus initiated a project to calibrate a replacement batch in International Units against the WHO 3(rd) International Standard (IS) for Erythropoietin, recombinant, for bioassay (11/170). A Ph. Eur. Chemical Reference Substance (CRS) was established recently for use as reference in some of the physicochemical tests prescribed in the monograph. Therefore, the EPO BRP batch 4 was only calibrated for the normocythaemic and polycythaemic mouse in vivo bioassays described in the Assay section of the Ph. Eur. monograph (1316). The collaborative study involved seven laboratories from Europe, the USA and South America. The results confirmed that the candidate BRP (cBRP) is suitable for use as a reference preparation in the potency determination of EPO medicinal products by bioassay (using the normocythaemic or polycythaemic mouse methods). The outcome of the study enabled the Ph. Eur. Commission to establish the proposed standard as erythropoietin BRP batch 4 in November 2014 for use as a reference preparation solely for the polycythaemic and normocythaemic mouse bioassay, with an assigned potency of 13 000 IU/vial. Furthermore, the potency of BRP3 was confirmed during the study, thus warranting a good continuity of the IU.

Test system stability and natural variability of a Lemna gibba L. bioassay.

PubMed

Scherr, Claudia; Simon, Meinhard; Spranger, Jörg; Baumgartner, Stephan

2008-09-04

In ecotoxicological and environmental studies Lemna spp. are used as test organisms due to their small size, rapid predominantly vegetative reproduction, easy handling and high sensitivity to various chemicals. However, there is not much information available concerning spatial and temporal stability of experimental set-ups used for Lemna bioassays, though this is essential for interpretation and reliability of results. We therefore investigated stability and natural variability of a Lemna gibba bioassay assessing area-related and frond number-related growth rates under controlled laboratory conditions over about one year. Lemna gibba L. was grown in beakers with Steinberg medium for one week. Area-related and frond number-related growth rates (r(area) and r(num)) were determined with a non-destructive image processing system. To assess inter-experimental stability, 35 independent experiments were performed with 10 beakers each in the course of one year. We observed changes in growth rates by a factor of two over time. These did not correlate well with temperature or relative humidity in the growth chamber. In order to assess intra-experimental stability, we analysed six systematic negative control experiments (nontoxicant tests) with 96 replicate beakers each. Evaluation showed that the chosen experimental set-up was stable and did not produce false positive results. The coefficient of variation was lower for r(area) (2.99%) than for r(num) (4.27%). It is hypothesised that the variations in growth rates over time under controlled conditions are partly due to endogenic periodicities in Lemna gibba. The relevance of these variations for toxicity investigations should be investigated more closely. Area-related growth rate seems to be more precise as non-destructive calculation parameter than number-related growth rate. Furthermore, we propose two new validity criteria for Lemna gibba bioassays: variability of average specific and section-by-section segmented growth rate, complementary to average specific growth rate as the only validity criterion existing in guidelines for duckweed bioassays.

Test System Stability and Natural Variability of a Lemna Gibba L. Bioassay

PubMed Central

Scherr, Claudia; Simon, Meinhard; Spranger, Jörg; Baumgartner, Stephan

2008-01-01

Background In ecotoxicological and environmental studies Lemna spp. are used as test organisms due to their small size, rapid predominantly vegetative reproduction, easy handling and high sensitivity to various chemicals. However, there is not much information available concerning spatial and temporal stability of experimental set-ups used for Lemna bioassays, though this is essential for interpretation and reliability of results. We therefore investigated stability and natural variability of a Lemna gibba bioassay assessing area-related and frond number-related growth rates under controlled laboratory conditions over about one year. Methology/Principal Findings Lemna gibba L. was grown in beakers with Steinberg medium for one week. Area-related and frond number-related growth rates (r(area) and r(num)) were determined with a non-destructive image processing system. To assess inter-experimental stability, 35 independent experiments were performed with 10 beakers each in the course of one year. We observed changes in growth rates by a factor of two over time. These did not correlate well with temperature or relative humidity in the growth chamber. In order to assess intra-experimental stability, we analysed six systematic negative control experiments (nontoxicant tests) with 96 replicate beakers each. Evaluation showed that the chosen experimental set-up was stable and did not produce false positive results. The coefficient of variation was lower for r(area) (2.99%) than for r(num) (4.27%). Conclusions/Significance It is hypothesised that the variations in growth rates over time under controlled conditions are partly due to endogenic periodicities in Lemna gibba. The relevance of these variations for toxicity investigations should be investigated more closely. Area-related growth rate seems to be more precise as non-destructive calculation parameter than number-related growth rate. Furthermore, we propose two new validity criteria for Lemna gibba bioassays: variability of average specific and section-by-section segmented growth rate, complementary to average specific growth rate as the only validity criterion existing in guidelines for duckweed bioassays. PMID:18769541

Introduction to a standardized method for the evaluation of the potency of Bacillus thuringiensis serotype H-14 based products*

PubMed Central

Rishikesh, N.; Quélennec, G.

1983-01-01

Vector resistance and other constraints have necessitated consideration of the use of alternative materials and methods in an integrated approach to vector control. Bacillus thuringiensis serotype H-14 is a promising biological control agent which acts as a conventional larvicide through its delta-endotoxin (active ingredient) and which now has to be suitably formulated for application in vector breeding habitats. The active ingredient in the formulations has so far not been chemically characterized or quantified and therefore recourse has to be taken to a bioassay method. Drawing on past experience and through the assistance mainly of various collaborating centres, the World Health Organization has standardized a bioassay method (described in the Annex), which gives consistent and reproducible results. The method permits the determination of the potency of a B.t. H-14 preparation through comparison with a standard powder. The universal adoption of the standardized bioassay method will ensure comparability of the results of different investigators. PMID:6601545

Detection of anabolic androgenic steroid abuse in doping control using mammalian reporter gene bioassays.

PubMed

Houtman, Corine J; Sterk, Saskia S; van de Heijning, Monique P M; Brouwer, Abraham; Stephany, Rainer W; van der Burg, Bart; Sonneveld, Edwin

2009-04-01

Anabolic androgenic steroids (AAS) are a class of steroid hormones related to the male hormone testosterone. They are frequently detected as drugs in sport doping control. Being similar to or derived from natural male hormones, AAS share the activation of the androgen receptor (AR) as common mechanism of action. The mammalian androgen responsive reporter gene assay (AR CALUX bioassay), measuring compounds interacting with the AR can be used for the analysis of AAS without the necessity of knowing their chemical structure beforehand, whereas current chemical-analytical approaches may have difficulty in detecting compounds with unknown structures, such as designer steroids. This study demonstrated that AAS prohibited in sports and potential designer AAS can be detected with this AR reporter gene assay, but that also additional steroid activities of AAS could be found using additional mammalian bioassays for other types of steroid hormones. Mixtures of AAS were found to behave additively in the AR reporter gene assay showing that it is possible to use this method for complex mixtures as are found in doping control samples, including mixtures that are a result of multi drug use. To test if mammalian reporter gene assays could be used for the detection of AAS in urine samples, background steroidal activities were measured. AAS-spiked urine samples, mimicking doping positive samples, showed significantly higher androgenic activities than unspiked samples. GC-MS analysis of endogenous androgens and AR reporter gene assay analysis of urine samples showed how a combined chemical-analytical and bioassay approach can be used to identify samples containing AAS. The results indicate that the AR reporter gene assay, in addition to chemical-analytical methods, can be a valuable tool for the analysis of AAS for doping control purposes.

A Miniature Bioassay for Testing the Acute Phytotoxicity of Photosystem II Herbicides on Seagrass

PubMed Central

Wilkinson, Adam D.; Collier, Catherine J.; Flores, Florita; Mercurio, Phil; O’Brien, Jake; Ralph, Peter J.; Negri, Andrew P.

2015-01-01

Photosystem II (PSII) herbicides have been detected in nearshore tropical waters such as those of the Great Barrier Reef and may add to the pressure posed by runoff containing sediments and nutrients to threatened seagrass habitats. There is a growing number of studies into the potential effects of herbicides on seagrass, generally using large experimental setups with potted plants. Here we describe the successful development of an acute 12-well plate phytotoxicity assay for the PSII herbicide Diuron using isolated Halophila ovalis leaves. Fluorescence images demonstrated Diuron affected the entire leaf surface evenly and responses were not influenced by isolating leaves from the plant. The optimum exposure duration was 24 h, by which time the inhibition of effective quantum yield of PSII (∆F/Fm’) was highest and no deterioration of photosystems was evident in control leaves. The inhibition of ∆F/Fm’ by Diuron in isolated H. ovalis leaves was identical to both potted and hydroponically grown plants (with leaves remaining attached to rhizomes), indicating similar reductions in photosynthetic activity in these acute well-plate assays. The sensitivity of the assay was not influenced by irradiance (range tested 40 to 400 μmol photons m-2 s-1). High irradiance, however, caused photo-oxidative stress in H. ovalis and this generally impacted in an additive or sub-additive way with Diuron to damage PSII. The bioassay using isolated leaves is more rapid, uses far less biological material and does not rely on specialised aquarium facilities in comparison with assays using potted plants. The development and validation of this sensitive bioassay will be useful to reliably screen and monitor the phytotoxicity of existing and emerging PSII herbicides and contribute to risk assessments and water quality guideline development in the future. PMID:25674791

Monitoring Cyp2b10 mRNA expression at cessation of 2-year carcinogenesis bioassay in mouse liver provides evidence for a carcinogenic mechanism devoid of human relevance: The dalcetrapib experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoflack, J-C.; Mueller, L., E-mail: Lutz.Mueller@roche.com; Fowler, S.

2012-03-15

Introduction: Dalcetrapib is a cholesteryl ester transfer protein (CETP) modulator in clinical assessment for cardiovascular outcome benefits. In compliance with regulatory requirements, dalcetrapib was evaluated in rodent 2-year carcinogenesis bioassays. In the mouse bioassay, male mice demonstrated increased liver weight and statistically increased incidences of hepatocellular adenoma/carcinoma. Hepatic cytochrome p450 (Cyp) 2b10 mRNA induction and increased Cyp2b10 enzyme activity signify activation of hepatic nuclear receptor constitutive androstane receptor (CAR), a widely established promoter of rodent-specific hepatic tumors. We therefore monitored hepatic Cyp2b10 mRNA and its enzyme activity in a subset of dalcetrapib-treated male mice from the bioassay. Methods: Liver samplesmore » were obtained from ∼ 1/3 of male mice from each dose group including vehicle-controls (mean and earliest study day of death 678 and 459 respectively). Quantitative real time PCR (qRT-PCR) was performed to determine Cyp2b10 mRNA expression and Cyp1a-, Cyp2b10- and Cyp3a-selective activities were monitored. Results: Cyp2b10 mRNA was strongly induced by dalcetrapib with an expected wide inter-individual variation (5–1421-fold). Group average fold-induction versus vehicle-controls showed a dose-related increase from 48-fold (250 mg/kg/day) to 160-fold (750 mg/kg/day), which declined slightly at 2000 mg/kg/day (97-fold). Cyp enzyme activities showed approximate doubling of total Cyp P450 content per milligram protein and a 9-fold increase in Cyp2b10-selective pentoxyresorufin O-dealkylase activity (750 mg/kg/day). Discussion: These data from hepatic Cyp2b10 monitoring are strongly suggestive of CAR activation by dalcetrapib, a mechanism devoid of relevance towards hepatocarcinogenesis in humans; results show feasibility of Cyp2b10 as a surrogate marker for this mechanism at cessation of a carcinogenesis bioassay. -- Highlights: ► Liver tumors were induced in male mice by dalcetrapib in a 2-y study (bioassay). ► Cyp2b10 induction typifies activation of nuclear receptor CAR in mouse liver. ► First report of hepatic Cyp2b10 monitoring at the end of a mouse bioassay. ► Cyp2b10 induction supports CAR activation by dalcetrapib in mouse bioassay. ► CAR activation is a mechanism of hepatic tumorigenesis of no relevance to humans.« less

Items Supporting the Hanford Internal Dosimetry Program Implementation of the IMBA Computer Code

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Bihl, Donald E.

2008-01-07

The Hanford Internal Dosimetry Program has adopted the computer code IMBA (Integrated Modules for Bioassay Analysis) as its primary code for bioassay data evaluation and dose assessment using methodologies of ICRP Publications 60, 66, 67, 68, and 78. The adoption of this code was part of the implementation plan for the June 8, 2007 amendments to 10 CFR 835. This information release includes action items unique to IMBA that were required by PNNL quality assurance standards for implementation of safety software. Copie of the IMBA software verification test plan and the outline of the briefing given to new users aremore » also included.« less

Immunoassay and Nb2 lymphoma bioassay prolactin levels and mammographic density in premenopausal and postmenopausal women the Nurses' Health Studies.

PubMed

Rice, Megan S; Tworoger, Shelley S; Bertrand, Kimberly A; Hankinson, Susan E; Rosner, Bernard A; Feeney, Yvonne B; Clevenger, Charles V; Tamimi, Rulla M

2015-01-01

Higher circulating prolactin levels have been associated with higher percent mammographic density among postmenopausal women in some, but not all studies. However, few studies have examined associations with dense area and non-dense breast area breast or considered associations with prolactin Nb2 lymphoma cell bioassay levels. We conducted a cross-sectional study among 1,124 premenopausal and 890 postmenopausal women who were controls in breast cancer case-control studies nested in the Nurses' Health Study (NHS) and NHSII. Participants provided blood samples in 1989-1990 (NHS) or 1996-1999 (NHSII) and mammograms were obtained from around the time of blood draw. Multivariable linear models were used to assess the associations between prolactin levels (measured by immunoassay or bioassay) with percent density, dense area, and non-dense area. Among 1,124 premenopausal women, percent density, dense area, and non-dense area were not associated with prolactin immunoassay levels in multivariable models (p trends = 0.10, 0.18, and 0.69, respectively). Among 890 postmenopausal women, those with prolactin immunoassay levels in the highest versus lowest quartile had modestly, though significantly, higher percent density (difference = 3.01 percentage points, 95 % CI 0.22, 5.80) as well as lower non-dense area (p trend = 0.02). Among women with both immunoassay and bioassay levels, there were no consistent differences in the associations with percent density between bioassay and immunoassay levels. Postmenopausal women with prolactin immunoassay levels in the highest quartile had significantly higher percent density as well as lower non-dense area compared to those in the lowest quartile. Future studies should examine the underlying biologic mechanisms, particularly for non-dense area.

A novel bronchial ring bioassay for the evaluation of small airway smooth muscle function in mice.

PubMed

Liu, John Q; Yang, Dennis; Folz, Rodney J

2006-08-01

Advances in our understanding of murine airway physiology have been hindered by the lack of suitable, ex vivo, small airway bioassay systems. In this study, we introduce a novel small murine airway bioassay system that permits the physiological and pharmacological study of intrapulmonary bronchial smooth muscle via a bronchial ring (BR) preparation utilizing BR segments as small as 200 microm in diameter. Using this ex vivo BR bioassay, we characterized small airway smooth muscle contraction and relaxation in the presence and absence of bronchial epithelium. In control BRs, the application of mechanical stretch is followed by spontaneous bronchial smooth muscle relaxation. BRs pretreated with methacholine (MCh) partially attenuate this stretch-induced relaxation by as much as 42% compared with control. MCh elicited a dose-dependent bronchial constriction with a maximal tension (E(max)) of 8.7 +/- 0.2 mN at an EC(50) of 0.33 +/- 0.02 microM. In the presence of nifedipine, ryanodine, 2-aminoethoxydiphenyl borate, and SKF-96365, E(max) to MCh was significantly reduced. In epithelium-denuded BRs, MCh-induced contraction was significantly enhanced to 11.4 +/- 1.0 mN with an EC(50) of 0.16 +/- 0.04 microM (P < 0.01). Substance P relaxed MCh-precontracted BR by 62.1%; however, this bronchial relaxation effect was completely lost in epithelium-denuded BRs. Papaverine virtually abolished MCh-induced constriction in both epithelium-intact and epithelium-denuded bronchial smooth muscle. In conclusion, this study introduces a novel murine small airway BR bioassay that allows for the physiological study of smooth muscle airway contractile responses that may aid in our understanding of the pathophysiology of asthma.

Long-lasting control of Anopheles arabiensis by a single spray application of micro-encapsulated pirimiphos-methyl (Actellic® 300 CS)

PubMed Central

2014-01-01

Background Pyrethroid-resistant mosquitoes are an increasing threat to malaria vector control. The Global Plan for Insecticide Resistance Management (GPIRM) recommends rotation of non-pyrethroid insecticides for indoor residual spraying (IRS). The options from other classes are limited. The carbamate bendiocarb and the organophosphate pirimiphos-methyl (p-methyl) emulsifiable concentrate (EC) have a short residual duration of action, resulting in increased costs due to multiple spray cycles, and user fatigue. Encapsulation (CS) technology was used to extend the residual performance of p-methyl. Methods Two novel p-methyl CS formulations were evaluated alongside the existing EC in laboratory bioassays and experimental hut trials in Tanzania between 2008-2010. Bioassays were carried out monthly on sprayed substrates of mud, concrete, plywood, and palm thatch to assess residual activity. Experimental huts were used to assess efficacy against wild free-flying Anopheles arabiensis, in terms of insecticide-induced mortality and blood-feeding inhibition. Results In laboratory bioassays of An. arabiensis and Culex quinquefasciatus both CS formulations produced high rates of mortality for significantly longer than the EC formulation on all substrates. On mud, the best performing CS killed >80% of An. arabiensis for five months and >50% for eight months, compared with one and two months, respectively, for the EC. In monthly bioassays of experimental hut walls the EC was ineffective shortly after spraying, while the best CS formulation killed more than 80% of An. arabiensis for five months on mud, and seven months on concrete. In experimental huts both CS and EC formulations killed high proportions of free-flying wild An. arabiensis for up to 12 months after spraying. There was no significant difference between treatments. All treatments provided considerable personal protection, with blood-feeding inhibition ranging from 9-49% over time. Conclusions The long residual performance of p-methyl CS was consistent in bioassays and experimental huts. The CS outperformed the EC in laboratory and hut bioassays but the EC longevity in huts was unexpected. Long-lasting p-methyl CS formulations should be more effective than both p-methyl EC and bendiocarb considering a single spray could be sufficient for annual malaria control. IRS with p-methyl 300 CS is a timely addition to the limited portfolio of long-lasting residual insecticides. PMID:24476070

A new bioassay for the inspection and identification of TBT-containing antifouling paint.

PubMed

Gueuné, Hervé; Thouand, Gérald; Durand, Marie-José

2009-11-01

Since the 1960s tributyl (TBT)-based antifouling paints are widely applied to protect ship's hulls from biofouling. Due to its high toxicity to aquatic ecosystem most of the countries (28 nations in 2008) signed the AFS convention to control the use of harmful antifouling systems on ships. Nevertheless there is currently no simple method to control the presence of organotin in paint. In this study, we propose a bioassay based on the use of a recombinant bioluminescent bacteria to detect directly in paint the presence of TBT. We also propose a simple device as an inspection system to control the absence of organotin in the ship's hull paint. The presence of organotin could be revealed in less than three hours.

Evaluating the efficacy of biological and conventional insecticides with the new 'MCD bottle' bioassay.

PubMed

Sternberg, Eleanore D; Waite, Jessica L; Thomas, Matthew B

2014-12-16

Control of mosquitoes requires the ability to evaluate new insecticides and to monitor resistance to existing insecticides. Monitoring tools should be flexible and low cost so that they can be deployed in remote, resource poor areas. Ideally, a bioassay should be able to simulate transient contact between mosquitoes and insecticides, and it should allow for excito-repellency and avoidance behaviour in mosquitoes. Presented here is a new bioassay, which has been designed to meet these criteria. This bioassay was developed as part of the Mosquito Contamination Device (MCD) project and, therefore, is referred to as the MCD bottle bioassay. Presented here are two experiments that serve as a proof-of-concept for the MCD bottle bioassay. The experiments used four insecticide products, ranging from fast-acting, permethrin-treated, long-lasting insecticide nets (LLINs) that are already widely used for malaria vector control, to the slower acting entomopathogenic fungus, Beauveria bassiana, that is currently being evaluated as a prospective biological insecticide. The first experiment used the MCD bottle to test the effect of four different insecticides on Anopheles stephensi with a range of exposure times (1 minute, 3 minutes, 1 hour). The second experiment is a direct comparison of the MCD bottle and World Health Organization (WHO) cone bioassay that tests a subset of the insecticides (a piece of LLIN and a piece of netting coated with B. bassiana spores) and a further reduced exposure time (5 seconds) against both An. stephensi and Anopheles gambiae. Immediate knockdown and mortality after 24 hours were assessed using logistic regression and daily survival was assessed using Cox proportional hazards models. Across both experiments, fungus performed much more consistently than the chemical insecticides but measuring the effect of fungus required monitoring of mosquito mortality over several days to a week. Qualitatively, the MCD bottle and WHO cone performed comparably, although knockdown and 24 hour mortality tended to be higher in some, but not all, groups of mosquitoes exposed using the WHO cone. The MCD bottle is feasible as a flexible, low-cost method for testing insecticidal materials. It is promising as a tool for testing transient contact and for capturing the effects of mosquito behavioural responses to insecticides.

CORRELATION OF COLIFORM GROWTH RESPONSE WITH OTHER WATER QUALITY PARAMETERS

EPA Science Inventory

A variety of water types collected from different geographical areas at different stages of water treatment were anlayzed for their ability to support the growth of coliform bacteria. Based on this coliform bioassay, the nutrient status of the water did not correlate with any of...

Involvement of Dactylonectria and Ilyonectria spp. in tree decline affecting multigeneration apple orchards

USDA-ARS?s Scientific Manuscript database

This study examined the etiology of typical replant disease symptom development, including growth reduction and leaf chlorosis, that was limited to specific foci within three multi-generation apple orchards that overall demonstrated optimal growth and good quality standard production. In bioassays c...

In vitro activity of ten essential oils against Sarcoptes scabiei.

PubMed

Fang, Fang; Candy, Kerdalidec; Melloul, Elise; Bernigaud, Charlotte; Chai, Ling; Darmon, Céline; Durand, Rémy; Botterel, Françoise; Chosidow, Olivier; Izri, Arezki; Huang, Weiyi; Guillot, Jacques

2016-11-22

The development of alternative approaches in ectoparasite management is currently required. Essential oils have been demonstrated to exhibit fumigant and topical toxicity to a number of arthropods. The aim of the present study was to assess the potential efficacy of ten essential oils against Sarcoptes scabiei. The major chemical components of the oils were identified by GC-MS analysis. Contact and fumigation bioassays were performed on Sarcoptes mites collected from experimentally infected pigs. For contact bioassays, essential oils were diluted with paraffin to get concentrations at 10, 5, and even 1% for the most efficient ones. The mites were inspected under a stereomicroscope 10, 20, 30, 40, 50, 60, 90, 120, 150, and 180min after contact. For fumigation bioassay, a filter paper was treated with 100 μL of the pure essential oil. The mites were inspected under a stereomicroscope for the first 5min, and then every 5min until 1h. Using contact bioassays, 1% clove and palmarosa oil killed all the mites within 20 and 50min, respectively. The oils efficacy order was: clove > palmarosa > geranium > tea tree > lavender > manuka > bitter orange > eucalyptus > Japanese cedar. In fumigation bioassays, the efficacy order was: tea tree > clove > eucalyptus > lavender > palmarosa > geranium > Japanese cedar > bitter orange > manuka. In both bioassays, cade oil showed no activity. Essential oils, especially tea tree, clove, palmarosa, and eucalyptus oils, are potential complementary or alternative products to treat S. scabiei infections in humans or animals, as well as to control the mites in the environment.

Systems for animal exposure in full-scale fire tests

NASA Technical Reports Server (NTRS)

Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

1977-01-01

Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

Evaluation of Short-Term Bioassays to Predict Functional Impairment, Development of Neurobehavioral Bioassays in Laboratory Animals, Directory of Institutions/Individuals.

DTIC Science & Technology

1980-10-01

0vna /eet &ku, 1 -0 - /.)GP-urna reenaway, James Konz // Oct&l =80 A Supported by - - US Army Medical Research and Development Command Fort Detrick...Contracting Officer’s Technical Representative: Mary C. Henry, Ph.D. D -A US Army Medical Bioengineering Research and Development Laboratory Fort Detrick...Virginia__22102 ______________ 11. CONTROLLING OFFICE NAME AND AD13RESS 12. REPORT DATE U.S. Army Medical Research and Development Commani October 1980 Fort

Evaluation of contaminant removal of reverse osmosis and advanced oxidation in full-scale operation by combining passive sampling with chemical analysis and bioanalytical tools.

PubMed

Escher, Beate I; Lawrence, Michael; Macova, Miroslava; Mueller, Jochen F; Poussade, Yvan; Robillot, Cedric; Roux, Annalie; Gernjak, Wolfgang

2011-06-15

Advanced water treatment of secondary treated effluent requires stringent quality control to achieve a water quality suitable for augmenting drinking water supplies. The removal of micropollutants such as pesticides, industrial chemicals, endocrine disrupting chemicals (EDC), pharmaceuticals, and personal care products (PPCP) is paramount. As the concentrations of individual contaminants are typically low, frequent analytical screening is both laborious and costly. We propose and validate an approach for continuous monitoring by applying passive sampling with Empore disks in vessels that were designed to slow down the water flow, and thus uptake kinetics, and ensure that the uptake is only marginally dependent on the chemicals' physicochemical properties over a relatively narrow molecular size range. This design not only assured integrative sampling over 27 days for a broad range of chemicals but also permitted the use of a suite of bioanalytical tools as sum parameters, representative of mixtures of chemicals with a common mode of toxic action. Bioassays proved to be more sensitive than chemical analysis to assess the removal of organic micropollutants by reverse osmosis, followed by UV/H₂O₂ treatment, as many individual compounds fell below the quantification limit of chemical analysis, yet still contributed to the observed mixture toxicity. Nonetheless in several cases, the responses in the bioassays were also below their quantification limits and therefore only three bioassays were evaluated here, representing nonspecific toxicity and two specific end points for estrogenicity and photosynthesis inhibition. Chemical analytical techniques were able to quantify 32 pesticides, 62 PCPPs, and 12 EDCs in reverse osmosis concentrate. However, these chemicals could explain only 1% of the nonspecific toxicity in the Microtox assay in the reverse osmosis concentrate and 0.0025% in the treated water. Likewise only 1% of the estrogenic effect in the E-SCREEN could be explained by the quantified EDCs after reverse osmosis. In comparison, >50% of the estrogenic effect can typically be explained in sewage. Herbicidal activity could be fully explained by chemical analysis as the sampling period coincided with an illegal discharge and two herbicides dominated the mixture effect. The mass balance of the reverse osmosis process matched theoretical expectations for both chemical analysis and bioanalytical tools. Overall the investigated treatment train removed >97% estrogenicity, >99% herbicidal activity, and >96% baseline toxicity, confirming the suitability of the treatment train for polishing water for indirect potable reuse. The product water was indistinguishable from local tap water in all three bioassays. This study demonstrates the suitability and robustness of passive sampling linked with bioanalytical tools for semicontinuous monitoring of advanced water treatment with respect to micropollutant removal.

Application Site and Mosquito Age Influences Malathion- and Permethrin-Induced Mortality in Culex quinquefasciatus (Diptera: Culicidae).

PubMed

Aldridge, Robert L; Kaufman, Phillip E; Bloomquist, Jeffrey R; Gezan, Salvador A; Linthicum, Kenneth J

2017-11-07

Concentrations of malathion and permethrin typical in droplets generated from ultra-low-volume and low-volume applications used to control mosquito populations were evaluated for efficacy against multiple-aged Culex quinquefasciatus Say (Diptera: Culicidae), using a topical bioassay. Although insecticide droplets will impinge on many exoskeletal body regions and a range of ages of mosquitoes in a population, traditional mosquito topical bioassays focus pesticide application to the mesothoracic pleural or dorsal regions across an average mosquito age (e.g., 3-7 d). Our results document nonuniform insecticide sensitivity across body regions at ages not previously assessed in mosquitoes (teneral and 14-d old). We expect our findings to influence the topical bioassay process, illustrating the difference in mosquito body regions and ages that ultimately may explain insecticide effectiveness wherever droplets impinge upon the mosquito body during field control applications. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Diagnostic Doses of Insecticides for Adult Aedes aegypti to Assess Insecticide Resistance in Cuba.

PubMed

Rodríguez, María Magdalena; Crespo, Ariel; Hurtado, Daymi; Fuentes, Ilario; Rey, Jorge; Bisset, Juan Andrés

2017-06-01

The objective of this study was to determine diagnostic doses (DDs) of 5 insecticides for the Rockefeller susceptible strain of Aedes aegypti , using the Centers for Disease Control and Prevention (CDC) bottle bioassay as a tool for monitoring insecticide resistance in the Cuban vector control program. The 30-min DD values determined in this study were 13.5 μg/ml, 6.5 μg/ml, 6 μg/ml, 90.0 μg/ml, and 15.0 μg/ml for cypermethrin, deltamethrin, lambda-cyhalothrin, chlorpyrifos, and propoxur, respectively. To compare the reliability of CDC bottle bioassay with the World Health Organization susceptible test, 3 insecticide-resistant strains were evaluated for deltamethrin and lambda-cyhalothrin. Results showed that the bottles can be used effectively from 21 to 25 days after treatment and reused up to 4 times, depending on the storage time. The CDC bottle bioassay is an effective tool to assess insecticide resistance in field populations of Ae. aegypti in Cuba and can be incorporated into vector management programs using the diagnostic doses determined in this study.

Cumulative assessment of steroid receptor mediated activity of contaminants in water samples using in vitro bioassays. -EMGS

EPA Science Inventory

Cell-based in vitro assays show promise for water quality monitoring applications due to high sensitivity, the ability to quantitatively detect a biologically relevant effect endpoint such as receptor transactivation (i.e., effect-based monitoring), and the ability to assess comp...

Hyalella azteca Responses to Coldwater River Backwater Sediments in Mississippi, USA

USDA-ARS?s Scientific Manuscript database

As part of an environmental quality assessment, sediment from four sites in three Coldwater River, Mississippi backwaters was examined using 28 d Hyalella azteca bioassays and chemical analyses for 33 pesticides, 7 metals and 7 PCBs. Mortality occurred in the DeSoto County backwater while growth imp...

Toxicity of selected acaricides in a glass-vial bioassay to two-spotted spider mite (Acari: Tetranychidae)

USDA-ARS?s Scientific Manuscript database

Two-spotted spider mite (TSSM), Tetranychus urticae Koch, feeds on epidermal cells of cotton foliage, destroys photosynthetic cells, and reduces yields, fiber quality and seed germination. With a short life cycle, prolific fecundity, an arrhenotokous reproduction, and an ability to expeditiously dig...

Proof of concept for a novel insecticide bioassay based on sugar feeding by adult Aedes aegypti (Stegomyia aegypti).

PubMed

Stell, F M; Roe, R M; Arellano, C; Kennedy, L; Thornton, H; Saavedra-Rodriguez, K; Wesson, D M; Black, W C; Apperson, C S

2013-09-01

Aedes aegypti L. (Stegomyia aegypti) (Diptera: Culicidae) is the principal vector of dengue and yellow fever viruses in tropical and subtropical regions of the world. Disease management is largely based on mosquito control achieved by insecticides applied to interior resting surfaces and through space sprays. Population monitoring to detect insecticide resistance is a significant component of integrated disease management programmes. We developed a bioassay method for assessing insecticide susceptibility based on the feeding activity of mosquitoes on plant sugars. Our prototype sugar-insecticide feeding bioassay system was composed of inexpensive, disposable components, contained minimal volumes of insecticide, and was compact and highly transportable. Individual mosquitoes were assayed in a plastic cup that contained a sucrose-permethrin solution. Trypan blue dye was added to create a visual marker in the mosquito's abdomen for ingested sucrose-permethrin solution. Blue faecal spots provided further evidence of solution ingestion. With the sugar-insecticide feeding bioassay, the permethrin susceptibility of Ae. aegypti females from two field-collected strains was characterized by probit analysis of dosage-response data. The field strains were also tested by forced contact of females with permethrin residues on filter paper. Dosage-response patterns were similar, indicating that the sugar-insecticide feeding bioassay had appropriately characterized the permethrin susceptibility of the two strains. © 2012 The Royal Entomological Society.

Analysis of therapeutic growth hormone preparations: report of an interlaboratory collaborative study on growth hormone assay methodologies.

PubMed

Bristow, A F; Jeffcoate, S L

1992-09-01

Recombinant DNA-derived human growth hormone (somatotropin) is widely used to treat growth hormone-deficient children. The potency of this product is determined by in-vivo bioassay in hypophysectomized rats, which is imprecise, costly and invasive, and there have been suggestions that it could safely be replaced with in-vitro or physico-chemical alternatives. In this report we present the results of a collaborative study designed to test this proposal. Somatotropin was modified by mild or severe proteolysis, mild or severe oxidation or treatment at high pH, and compared in a multi-centre collaborative study with unmodified somatotropin or with dimerized somatotropin. Participating laboratories included manufacturers and national control laboratories, and pharmacopoeial bioassays were compared with in-house in-vitro and physico-chemical bioassays. Although performing adequately with untreated somatotropin, for degraded samples the in-vivo bioassays were relatively unresponsive to changes in the growth hormone molecule. In contrast, the physico-chemical assays, in particular the reverse-phase HPLC, performed with a high degree of selectivity. We conclude that in the case of somatotropin, the in-vivo bioassay can be removed from the routine product specification with an acceptable degree of security. This however does not obviate the requirement rigorously to demonstrate biological activity in-vivo during product development, nor may the conclusions of this study be applied to other therapeutic recombinant proteins without similar collaborative investigations.

Diagnostic doses and times for Phlebotomus papatasi and Lutzomyia longipalpis sand flies (Diptera: Psychodidae: Phlebotominae) using the CDC bottle bioassay to assess insecticide resistance.

PubMed

Denlinger, David S; Creswell, Joseph A; Anderson, J Laine; Reese, Conor K; Bernhardt, Scott A

2016-04-15

Insecticide resistance to synthetic chemical insecticides is a worldwide concern in phlebotomine sand flies (Diptera: Psychodidae), the vectors of Leishmania spp. parasites. The CDC bottle bioassay assesses resistance by testing populations against verified diagnostic doses and diagnostic times for an insecticide, but the assay has been used limitedly with sand flies. The objective of this study was to determine diagnostic doses and diagnostic times for laboratory Lutzomyia longipalpis (Lutz & Nieva) and Phlebotomus papatasi (Scopoli) to ten insecticides, including pyrethroids, organophosphates, carbamates, and DDT, that are used worldwide to control vectors. Bioassays were conducted in 1,000-ml glass bottles each containing 10-25 sand flies from laboratory colonies of L. longipalpis or P. papatasi. Four pyrethroids, three organophosphates, two carbamates and one organochlorine, were evaluated. A series of concentrations were tested for each insecticide, and four replicates were conducted for each concentration. Diagnostic doses were determined only during the exposure bioassay for the organophosphates and carbamates. For the pyrethroids and DDT, diagnostic doses were determined for both the exposure bioassay and after a 24-hour recovery period. Both species are highly susceptible to the carbamates as their diagnostic doses are under 7.0 μg/ml. Both species are also highly susceptible to DDT during the exposure assay as their diagnostic doses are 7.5 μg/ml, yet their diagnostic doses for the 24-h recovery period are 650.0 μg/ml for Lu. longipalpis and 470.0 μg/ml for P. papatasi. Diagnostic doses and diagnostic times can now be incorporated into vector management programs that use the CDC bottle bioassay to assess insecticide resistance in field populations of Lu. longipalpis and P. papatasi. These findings provide initial starting points for determining diagnostic doses and diagnostic times for other sand fly vector species and wild populations using the CDC bottle bioassay.

Optimization and field use of a bioassay to monitor sea lice Lepeophtheirus salmonis sensitivity to emamectin benzoate.

PubMed

Westcott, Jillian D; Stryhn, Henrik; Burka, John F; Hammell, K Larry

2008-04-01

A bioassay for sea lice Lepeophtheirus salmonis sensitivity towards emamectin benzoate (EMB) was validated for field use. A probit regression model with natural responsiveness was used for the number of affected (moribund or dead) sea lice in bioassays involving different concentrations of EMB. Bioassay optimization included an evaluation of the inter-rater reliability of sea lice responsiveness to EMB and an evaluation of gender-related differences in susceptibility. Adoption of a set of bioassay response criteria improved the concordance (evaluated using the concordance correlation coefficient) between raters' assessments and the model estimation of EC50 values (the 'effective concentration' leading to a response of 50% of the lice not prone to natural response). An evaluation of gender-related differences in EMB susceptibility indicated that preadult stage female sea lice exhibited a significantly larger sensitivity towards EMB in 12 of 19 bioassays compared to preadult males. In order to evaluate sea lice sensitivity to EMB in eastern Canada, the intensive salmon farming area in the Bay of Fundy in southwestern New Brunswick was divided into 4 distinct regions based on industry health management practices and hydrographics. A total of 38 bioassays were completed from 2002 to 2005 using populations of preadult stage sea lice collected from Atlantic salmon Salmo salar farms within the 4 described regions. There was no significant overall effect of region or year on EC50 values; however, analysis of variance indicated a significant effect of time of year on EC50 values in 2002 and a potential effect in 2004 to 2005. Although the range of EC50 values obtained in this 3 yr study did not appear sufficient to affect current clinical success in the control of sea lice, the results suggest a seasonal- or temperature-associated variation in sensitivity to EMB. This will need to be considered if changes in EMB efficacy occur in the future.

Highly variable sensitivity of five binding and two bio-assays for TSH-receptor antibodies.

PubMed

Diana, T; Wüster, C; Kanitz, M; Kahaly, G J

2016-10-01

TSH-receptor (TSHR) antibodies (Ab) can be measured with binding or bio-assays. Sensitivity and specificity of five binding and two bio-assays were compared. TSHR-blocking (TBAb) and TSHR-stimulating (TSAb) Ab were measured with reporter bio-assays. Blocking activity was defined as percent inhibition of luciferase expression relative to induction with bTSH alone. TSAb was reported as percentage of specimen-to-reference ratio (SRR%). TSHR-binding inhibitory immunoglobulins (TBII) were measured with Kronus, Dynex, Kryptor, Cobas, and Immulite. Sixty patients with Graves' disease (GD), 20 with Hashimoto's thyroiditis (HT), and 20 healthy controls (C) were included. C tested negative in all assays (specificity 100 %) while all 60 hyperthyroid GD patients tested positive in the TSAb bio-assay (sensitivity 100 %). Among these 60 GD patients, 20 had low TSAb positivity (SRR% 140-279), but were TBII positive in only 20 (100 %), 7 (35 %), 9 (45 %), 11 (55 %), and 18 (90 %) using the Kronus, Dynex, Kryptor, Cobas, and Immulite, respectively. In 20 moderate TSAb-positive (SRR% 280-420) patients, TBII tested positive in 20 (100 %), 14 (70 %), 13 (65 %), 16 (80 %), and 19 (95 %), respectively. The high (SRR% > 420) TSAb-positive patients were all TBII positive. All 20 hypothyroid HT patients tested TBAb positive (sensitivity 100 %) in the bio-assay while they tested TBII positive in 20 (100 %), 18 (90 %), 20, 20, and 18, respectively. Results obtained with two luminometers correlated for TSAb positive (r = 0.99, p < 0.001), TBAb positive (r = 0.88, p < 0.001), and C (r = 0.86, p < 0.001). None of the binding assays differentiated between TSAb and TBAb. Sensitivity is highly variable between binding and bio-assays for TSHR-Abs.

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

PubMed

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

2009-07-01

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

Chlorfenapyr (A Pyrrole Insecticide) Applied Alone or as a Mixture with Alpha-Cypermethrin for Indoor Residual Spraying against Pyrethroid Resistant Anopheles gambiae sl: An Experimental Hut Study in Cove, Benin

PubMed Central

Ngufor, Corine; Critchley, Jessica; Fagbohoun, Josias; N’Guessan, Raphael; Todjinou, Damien; Rowland, Mark

2016-01-01

Background Indoor spraying of walls and ceilings with residual insecticide remains a primary method of malaria control. Insecticide resistance in malaria vectors is a growing problem. Novel insecticides for indoor residual spraying (IRS) which can improve the control of pyrethroid resistant malaria vectors are urgently needed. Insecticide mixtures have the potential to improve efficacy or even to manage resistance in some situations but this possibility remains underexplored experimentally. Chlorfenapyr is a novel pyrrole insecticide which has shown potential to improve the control of mosquitoes which are resistant to current WHO-approved insecticides. Method The efficacy of IRS with chlorfenapyr applied alone or as a mixture with alpha-cypermeththrin (a pyrethroid) was evaluated in experimental huts in Cove, Southern Benin against wild free flying pyrethroid resistant Anopheles gambiae sl. Comparison was made with IRS with alpha-cypermethrin alone. Fortnightly 30-minute in situ cone bioassays were performed to assess the residual efficacy of the insecticides on the treated hut walls. Results Survival rates of wild An gambiae from the Cove hut site in WHO resistance bioassays performed during the trial were >90% with permethrin and deltamethrin treated papers. Mortality of free-flying mosquitoes entering the experimental huts was 4% in the control hut. Mortality with alpha-cypermethrin IRS did not differ from the control (5%, P>0.656). The highest mortality was achieved with chlorfenapyr alone (63%). The alpha-cypermethrin + chlorfenapyr mixture killed fewer mosquitoes than chlorfenapyr alone (43% vs. 63%, P<0.001). While the cone bioassays showed a more rapid decline in residual mortality with chlorfenapyr IRS to <30% after only 2 weeks, fortnightly mortality rates of wild free-flying An gambiae entering the chlorfenapyr IRS huts were consistently high (50–70%) and prolonged, lasting over 4 months. Conclusion IRS with chlorfenapyr shows potential to significantly improve the control of malaria transmission in pyrethroid resistant areas compared to pyrethroid IRS or the mixture. Thirty minute in situ cone bioassays are not predictive of the performance of chlorfenapyr IRS under field conditions. PMID:27588945

Advantages and Limitations of Androgen Receptor-Based Methods for Detecting Anabolic Androgenic Steroid Abuse as Performance Enhancing Drugs.

PubMed

Bailey, Kathy; Yazdi, Tahmineh; Masharani, Umesh; Tyrrell, Blake; Butch, Anthony; Schaufele, Fred

2016-01-01

Testosterone (T) and related androgens are performance enhancing drugs (PEDs) abused by some athletes to gain competitive advantage. To monitor unauthorized androgen abuse, doping control programs use mass spectrometry (MS) to detect androgens, synthetic anabolic-androgenic steroids (AASs) and their metabolites in an athlete's urine. AASs of unknown composition will not be detected by these procedures. Since AASs achieve their anabolic effects by activating the Androgen Receptor (AR), cell-based bioassays that measure the effect of a urine sample on AR activity are under investigation as complementary, pan-androgen detection methods. We evaluated an AR BioAssay as a monitor for androgen activity in urine pre-treated with glucuronidase, which releases T from the inactive T-glucuronide that predominates in urine. AR BioAssay activity levels were expressed as 'T-equivalent' concentrations by comparison to a T dose response curve. The T-equivalent concentrations of androgens in the urine of hypogonadal participants supplemented with T (in whom all androgenic activity should arise from T) were quantitatively identical to the T measurements conducted by MS at the UCLA Olympic Analytical Laboratory (0.96 ± 0.22). All 17 AASs studied were active in the AR BioAssay; other steroids were inactive. 12 metabolites of 10 commonly abused AASs, which are used for MS monitoring of AAS doping because of their prolonged presence in urine, had reduced or no AR BioAssay activity. Thus, the AR BioAssay can accurately and inexpensively monitor T, but its ability to monitor urinary AASs will be limited to a period immediately following doping in which the active AASs remain intact.

EFFECT OF OZONATED WATER ON THE ASSIMILABLE ORGANIC CARBON AND COLIFORM GROWTH RESPONSE VALUES AND ON PATHOGENIC BACTERIA SURVIVAL

EPA Science Inventory

The assimilable organic carbon (AOC) and coliform growth response (CGR) are bioassays used to determine water quality. AOC and CGR are better indexes in determining whether water can support the growth of bacteria than biological oxygen demand (BOD). The AOC value of reconditione...

40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

Code of Federal Regulations, 2011 CFR

2011-07-01

... potential effects on the water column and on communities of aquatic organisms. (1) Evaluation of chemical... be obtained from bioassays in lieu of chemical tests. (2) Water column effects. (i) Sediments... locations within the sediment. An elutriate test may be used to predict the effect on water quality due to...

40 CFR 230.61 - Chemical, biological, and physical evaluation and testing.

Code of Federal Regulations, 2010 CFR

2010-07-01

... potential effects on the water column and on communities of aquatic organisms. (1) Evaluation of chemical... be obtained from bioassays in lieu of chemical tests. (2) Water column effects. (i) Sediments... locations within the sediment. An elutriate test may be used to predict the effect on water quality due to...

Comprehensive Characteristics of Bottom Sediments of Water Bodies of Various Types in the Kiliya Delta of the Danube River

EPA Science Inventory

The "triad" approach, including analysis of the total content of toxicants, bioassay of bottom sediments, and the study of the structure of zoo- and phytobenthos communities, was used in assessing the quality of bottom sediments. It has been found that the studied bottom sediment...

Vermicomposting of food waste: assessing the stability and maturity

PubMed Central

2012-01-01

The vermicompost using earthworms (Eisenia Fetida) was produced from food waste and chemical parameters (EC, pH, carbon to nitrogen contents (C/N)) and germination bioassay was examined in order to assess the stability and maturity indicators during the vermicomposting process. The seed used in the germination bioassay was cress. The ranges of EC, pH, C/N and germination index were 7.5-4.9 mS/cm, 5.6-7.53, 30.13-14.32% and 12.8-58.4%, respectively. The germination index (GI) value revealed that vermicompost rendered as moderate phytotoxic to cress seed. Pearson correlation coefficient was used to evaluate the relationship between the parameters. High statistically significant correlation coefficient was calculated between the GI value and EC in the vermicompost at the 99% confidence level. The C/N value showed that the vermicompost was stable. As a result of these observations, stability test alone, was not able to ensure high vermicompost quality. Therefore, it appears that determining vermicompost quality requires a simultaneous use of maturity and stability tests. PMID:23369642

Bioassay for Nisin in Milk, Processed Cheese, Salad Dressings, Canned Tomatoes, and Liquid Egg Products

PubMed Central

Hakovirta, J.; Reunanen, J.; Saris, P. E. J.

2006-01-01

A sensitive nisin quantification bioassay was constructed, based on Lactococcus lactis chromosomally encoding the nisin regulatory proteins NisK and NisR and a plasmid with a green fluorescent protein (GFP) variant gfpuv gene under the control of the nisin-inducible nisA promoter. This strain, LAC275, was capable of transducing the signal from extracellular nisin into measurable GFPuv fluorescence through the NisRK signal transduction system. The LAC275 cells detected nisin concentrations of 10 pg/ml in culture supernatant, 0.2 ng/ml in milk, 3.6 ng/g in processed cheese, 1 ng/g in salad dressings and crushed, canned tomatoes, and 2 ng/g in liquid egg. This method was up to 1,000 times more sensitive than a previously described GFP-based nisin bioassay. This new assay made it possible to detect significantly smaller amounts of nisin than the presently most sensitive published nisin bioassay based on nisin-induced bioluminescence. The major advantage of this sensitivity was that foods could be extensively diluted prior to the assay, avoiding potential inhibitory and interfering substances present in most food products. PMID:16461641

Leveraging advances in biology to design biomaterials

NASA Astrophysics Data System (ADS)

Darnell, Max; Mooney, David J.

2017-12-01

Biomaterials have dramatically increased in functionality and complexity, allowing unprecedented control over the cells that interact with them. From these engineering advances arises the prospect of improved biomaterial-based therapies, yet practical constraints favour simplicity. Tools from the biology community are enabling high-resolution and high-throughput bioassays that, if incorporated into a biomaterial design framework, could help achieve unprecedented functionality while minimizing the complexity of designs by identifying the most important material parameters and biological outputs. However, to avoid data explosions and to effectively match the information content of an assay with the goal of the experiment, material screens and bioassays must be arranged in specific ways. By borrowing methods to design experiments and workflows from the bioprocess engineering community, we outline a framework for the incorporation of next-generation bioassays into biomaterials design to effectively optimize function while minimizing complexity. This framework can inspire biomaterials designs that maximize functionality and translatability.

Bioassay of procoagulant albumin in human plasma.

PubMed

Grosset, A; Liu, L; Parker, C J; Rodgers, G M

1994-09-01

Procoagulant albumin (P-Al) is present in normal human plasma and increases monocyte and endothelial cell expression of tissue factor activity. To develop a bioassay for P-Al, we partially purified plasma from healthy volunteers and several patient groups using BaCl2 and (NH4)2SO4 precipitation. The samples were assayed for tissue factor (TF) inducing activity, expressed as a percentage increase compared to a serum-free media control. Over six months, the assay was reproducible in stored samples and in serial samples from normal volunteers. The plasma P-Al activities of 35 volunteers averaged 141 +/- 8.2% (SEM). There was no diurnal variation. There was no difference in the P-Al activity after a 12 hour fast and 2 hours after a large meal in 4 healthy volunteers. There was no increase in activity (r = 0.16) with the subject's age. The average activity from 16 poorly-controlled diabetics was 131 +/- 11% (SEM). No alteration in activity was seen with samples from patients with uremia, liver dysfunction, hemophilia, thrombotic events, or adenocarcinoma. These results indicate that P-Al activity can be bioassayed in individual patient samples; however, pathologic states associated with abnormal P-Al-induced tissue factor activity presently remain unidentified.

Use of a germination bioassay to test compost maturity in Tekelan Village

NASA Astrophysics Data System (ADS)

Oktiawan, Wiharyanto; Zaman, Badrus; Purwono

2018-02-01

Livestock waste from cattle farms in Tekelan village, Getasan Subdistrict, Semarang Regency can be grouped into three types, namely solid waste, slurry and waste water. Solid waste (cow dung) was processed into compost, while slurry and waste water were used to make liquid fertilizer. This compost was used as a component of planting media in horticultural crops and potted plants production. We evaluated the toxicity (phytochemical and ecotoxicological) test of compost by using germination index (GI). Vigna radiata seeds are sown on filter paper dampened with compost extract for different times. GI was calculated by relative germination (G) and relative radical length (L). The germination index (GI) = G / G0 x L / L0 x 100, where G0 and L0 are values obtained by distilled water as a control. The results showed that germination bioassay and radical length using aquades and groundwater in Tekelan village did not affect the radical length of Vigna radiata . Technically, groundwater in Tekelan village can be used as a germination bioassay control. The cow dung compost substrate appears to have a major influence on compost toxicity. Mature compost was produced on day 14 with a GI of 104.03.

Results of the Excreta Bioassay Quality Control Program for April 1, 2009 through March 31, 2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonio, Cheryl L.

2012-07-19

A total of 58 urine samples and 10 fecal samples were submitted during the report period (April 1, 2009 through March 31, 2010) to General Engineering Laboratories, South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for Sr, 238Pu, 239Pu, 241Am, 243Am 235U, 238U, elemental uranium and fecal analyses for 241Am, 238Pu and 239Pu were tested this year as well as four tissue samples for 238Pu, 239Pu, 241Am and 241Pu. The number of QC urine samples submitted during the report period represented 1.3% of the total samplesmore » submitted. In addition to the samples provided by IDP, GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 33% of the analyses processed by GEL during the third year of this contract were quality control samples. GEL tested the performance of 21 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty (Table 4).« less

Results of The Excreta Bioassay Quality Control Program For April 1, 2010 Through March 31, 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonio, Cheryl L.

2012-07-19

A total of 76 urine samples and 10 spiked fecal samples were submitted during the report period (April 1, 2010 through March 31, 2011) to GEL Laboratories, LLC in South Carolina by the Hanford Internal Dosimetry Program (IDP) to check the accuracy, precision, and detection levels of their analyses. Urine analyses for 14C, Sr, for 238Pu, 239Pu, 241Am, 243Am, 235U, 238U, 238U-mass and fecal analyses for 241Am, 238Pu and 239Pu were tested this year. The number of QC urine samples submitted during the report period represented 1.1% of the total samples submitted. In addition to the samples provided by IDP,more » GEL was also required to conduct their own QC program, and submit the results of analyses to IDP. About 31% of the analyses processed by GEL during the first year of contract 112512 were quality control samples. GEL tested the performance of 23 radioisotopes, all of which met or exceeded the specifications in the Statement of Work within statistical uncertainty except the slightly elevated relative bias for 243,244Cm (Table 4).« less

Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks.

PubMed

Madzimure, James; Nyahangare, Emmanuel T; Hamudikuwanda, Humphrey; Hove, Thokozani; Belmain, Steve R; Stevenson, Philip C; Mvumi, Brighton M

2013-08-01

The efficacy of Solanum incanum and Strychnos spinosa aqueous fruit extracts was evaluated against cattle ticks in on-station experiments and laboratory tick bioassays. In the on-station experiment using cattle, fruit extracts were applied at three concentrations 5, 10, and 20 % (w/v) and compared with a commercial acaricide, Tickbuster (amitraz) spray (positive control) and no treatment (negative control). The treatments were applied at weekly intervals for 6 weeks as surface sprays on 32 Mashona cattle in a completely randomized design experiment. Ticks on individual cattle were identified, counted, and recorded daily. Peripheral blood samples were collected for parasite screening. In the laboratory, tick bioassays were conducted at four concentrations, 5, 10, 20, and 40% (w/v) fruit extracts compared to Tickbuster (amitraz) spray (positive control) and distilled water (negative control). The extracts were incubated with Rhipicephalus (Boophilus) decoloratus tick larvae and mortalities for each treatment level recorded after 24 and 48 h. The 5% Solanum incanum treatment had higher efficacy ratio (P < 0.05) than the other fruit extract concentrations of the same plant species. Efficacy ratio was higher (P < 0.05) in the 5% S. spinosa-treated cattle than in the untreated control but lower (P < 0.05) than that for the amitraz treatment. The bioassays indicated that there was a high efficacy ratio for the lowest fruit extract concentrations when ticks were exposed to acaricidal treatments for 48 h compared to 24 h. Overall, the results indicate that Solanum incanum and Strychnos spinosa individually have some acaricidal effect.

A floatable formulation and laboratory bioassay of Pandora delphacis (Entomophthoromycota: Entomophthorales) for the control of rice pest Nilaparvata lugens Stål (Hemiptera: Delphacidae).

PubMed

Zhou, Xiang; Su, Xiu; Liu, Hongbo

2016-01-01

The brown planthopper (BPH), Nilaparvata lugens (Staparvata luera: Delphacidae), is a serious rice pest that easily develops resistance to chemical insecticides and resistant rice varieties. This study evaluated the infectivity of the BPH fungal pathogen, Pandora delphacis, and developed a novel formulation as an alternative means of BPH control. In a multiconidial concentration bioassay, P. delphacis-infected BPH cadavers were observed on day 4, but most occurred between days 5 and 8. BPH mortality depended on the inoculated conidial concentration. The cumulative mortality of adult BPHs reached 81.7% at 192 conidia mm(-2) in 8 days. Inoculation with 40.9 conidia mm(-2) was sufficient to induce 50% BPH death, based on analysis of a time-concentration-mortality model. A floatable P. delphacis-based formulation was made for use in paddy fields; mycelium-containing pellets mimicking mycosed cadavers could produce 7-15.7 × 10(4) infectious conidia pellet(-1) at 11-28 °C. In the laboratory bioassay, three floating pellets in a BPH-rearing jar caused 75.5% BPH mortality within 8 days, similar to the mortality level caused by direct conidial inoculation. P. delphacis is a potential biocontrol agent of BPHs for further research, and the novel floatable formulation holds promise as a method for BPH control. © 2015 Society of Chemical Industry.

Bioassays as one of the Green Chemistry tools for assessing environmental quality: A review.

PubMed

Wieczerzak, M; Namieśnik, J; Kudłak, B

2016-09-01

For centuries, mankind has contributed to irreversible environmental changes, but due to the modern science of recent decades, scientists are able to assess the scale of this impact. The introduction of laws and standards to ensure environmental cleanliness requires comprehensive environmental monitoring, which should also meet the requirements of Green Chemistry. The broad spectrum of Green Chemistry principle applications should also include all of the techniques and methods of pollutant analysis and environmental monitoring. The classical methods of chemical analyses do not always match the twelve principles of Green Chemistry, and they are often expensive and employ toxic and environmentally unfriendly solvents in large quantities. These solvents can generate hazardous and toxic waste while consuming large volumes of resources. Therefore, there is a need to develop reliable techniques that would not only meet the requirements of Green Analytical Chemistry, but they could also complement and sometimes provide an alternative to conventional classical analytical methods. These alternatives may be found in bioassays. Commercially available certified bioassays often come in the form of ready-to-use toxkits, and they are easy to use and relatively inexpensive in comparison with certain conventional analytical methods. The aim of this study is to provide evidence that bioassays can be a complementary alternative to classical methods of analysis and can fulfil Green Analytical Chemistry criteria. The test organisms discussed in this work include single-celled organisms, such as cell lines, fungi (yeast), and bacteria, and multicellular organisms, such as invertebrate and vertebrate animals and plants. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Exploration on feasibility of introducing bioassay method into quality evaluation of Chinese herbal medicines by studying on the correlation between antioxidant activity of Prunella vulgaris and its total phenolic acids content for example].

PubMed

Feng, Wei-Hong; Li, Chun; Xin, Wei-Mei; Lin, Li-Mei; Xia, Bo-Hou; Rong, Li-Xin; Yang, Li-Xin; Yi, Hong; Zhang, Yong-Xin; Chen, Liang-Mian; Wang, Zhi-Min

2016-07-01

This paper aims to investigate the correlation between the antioxidant activity of Prunella vulgaris and its total phenolic acids content by measuring the antioxidant activity of different sources and different organs of P. vulgaris and the total contents of protocatechuic acid, protocatechuic aldehyde, caffeic acid, salviaflaside and rosmarinic acid in these samples. Using the 50% methanol extract of P. vulgaris samples as the research object, DPPH method and HPLC method were used respectively to determine the antioxidant activities and the total contents of the above-mentioned five analytes in P. vulgaris samples. 0.5 mL of 50% methanol extract of P. vulgaris reacts with 0.1 mmol•L⁻¹ DPPH ethanol solution for 60 min, then the absorbance of the reaction solution was measured at 517 nm, scavenging rate and IC₅₀ values were calculated by the absorbance and the sample concentration for evaluating the antioxidant activity. HPLC analysis was made on a C₁₈ Epic column, with acetonitrile-0.1% formic acid aqueous solution as mobile phase (gradient elution), and the detection wavelength was set at 280 nm. The correlation between the antioxidant capacity of different habitats and different organs of P. vulgaris and the total contents of five kinds of phenolic acids was analyzed by partial least squares method. The reaction dose-response range of 50% methanol extract of P. vulgaris with 0.1 mmol•L⁻¹ DPPH ethanol solution was 0.300-1.65 g•L⁻¹. When the quantities of potocatechuic acid, protocatechuic aldehyde, caffeic acid, salviaflaside and rosmarinic acid were respectively in 0.007 84-0.980, 0.011 5-1.44, 0.008 64-1.08, 0.080 0-1.00 and 0.079 8-0.998 μg range, their quantities were in good linear relationship with the corresponding peak areas. The average recovery of 5 components were 97.76%, 96.88%, 100.3%, 102.1%, 104.5%, with RSD of 1.8%, 1.6%, 1.7%, 1.6% and 1.7%, respectively. In a certain range of crude drug quantity, the antioxidant activity of each organ of P. vulgaris and total phenolic acids content inside has a good linear correlation. Therefore, in certain quality range of crude drug, DPPH bioassay combined with HPLC content determination can be used for the quality control of P. vulgaris, as is a new method for the quality control of P. vulgaris. Copyright© by the Chinese Pharmaceutical Association.

Critical review and evaluation of the uterotrophic bioassay for the identification of possible estrogen agonists and antagonists: in support of the validation of the OECD uterotrophic protocols for the laboratory rodent. Organisation for Economic Co-operation and Development.

PubMed

Owens, J William; Ashby, John

2002-01-01

A current issue for regulatory agencies is endocrine-related modes of action such as those mediated by the estrogen, androgen, and thyroid nuclear receptors. At the national and international levels, the consensus recommendation for the assessment of such modes of action is a tiered series of in vitro and in vivo protocols. The tiered framework begins with screens for structural alerts and then moves to rapid, mechanistic in vitro screening assays, and then to in vivo screening bioassays. The objective of these screens is to identify substances that may warrant testing for endocrine-mediated adverse effects. The final framework tier as needed is to test these substances in long-term bioassays for adverse endocrine-mediated reproductive and/or developmental effects. The subject of this review, the rodent uterotrophic bioassay, is intended to be a rapid in vivo screening bioassay for possible estrogen agonists and based on the response of the estrogen-sensitive uterus. The central metric of bioassay is a statistically significant increase in the weight of the uterus after 3 consecutive days of test substance administration. The extensive background literature is summarized in this review on the mode of action underlying the bioassay and the uterine response to estrogens. The review includes the bioassay's history of development and how its employment has changed and evolved over time. The review describes two major uterotrophic bioassay versions, the intact, immature female and the mature, ovariectomized female, and the protocol factors likely to influence relevance, reproducibility, and reliability of bioassay. The emphasis of the review is the ability of the uterotrophic bioassay to identify the substances of current interest: weak estrogen agonists with binding affinities relative to the natural 17beta-estradiol in the log 0 to log -3 range. Using selected model substances having RBAs in this target range, the bioassay's performance in a hierarchical, tiered approach is evaluated, including the predictive capability of the uterotrophic bioassay based on available reproductive and developmental testing data. The review concludes that the uterotrophic bioassay is reliable and can identify substances that may act via an estrogen-mode of action, supporting the validity of the uterotrophic bioassay and its regulatory use as an in vivo mechanistic screening bioassay for estrogen agonists and antagonists.

Electroantennographic Bioassay as a Screening Tool for Host Plant Volatiles

PubMed Central

Beck, John J.; Light, Douglas M.; Gee, Wai S.

2012-01-01

Plant volatiles play an important role in plant-insect interactions. Herbivorous insects use plant volatiles, known as kairomones, to locate their host plant.1,2 When a host plant is an important agronomic commodity feeding damage by insect pests can inflict serious economic losses to growers. Accordingly, kairomones can be used as attractants to lure or confuse these insects and, thus, offer an environmentally friendly alternative to pesticides for insect control.3 Unfortunately, plants can emit a vast number volatiles with varying compositions and ratios of emissions dependent upon the phenology of the commodity or the time of day. This makes identification of biologically active components or blends of volatile components an arduous process. To help identify the bioactive components of host plant volatile emissions we employ the laboratory-based screening bioassay electroantennography (EAG). EAG is an effective tool to evaluate and record electrophysiologically the olfactory responses of an insect via their antennal receptors. The EAG screening process can help reduce the number of volatiles tested to identify promising bioactive components. However, EAG bioassays only provide information about activation of receptors. It does not provide information about the type of insect behavior the compound elicits; which could be as an attractant, repellent or other type of behavioral response. Volatiles eliciting a significant response by EAG, relative to an appropriate positive control, are typically taken on to further testing of behavioral responses of the insect pest. The experimental design presented will detail the methodology employed to screen almond-based host plant volatiles4,5 by measurement of the electrophysiological antennal responses of an adult insect pest navel orangeworm (Amyelois transitella) to single components and simple blends of components via EAG bioassay. The method utilizes two excised antennae placed across a "fork" electrode holder. The protocol demonstrated here presents a rapid, high-throughput standardized method for screening volatiles. Each volatile is at a set, constant amount as to standardize the stimulus level and thus allow antennal responses to be indicative of the relative chemoreceptivity. The negative control helps eliminate the electrophysiological response to both residual solvent and mechanical force of the puff. The positive control (in this instance acetophenone) is a single compound that has elicited a consistent response from male and female navel orangeworm (NOW) moth. An additional semiochemical standard that provides consistent response and is used for bioassay studies with the male NOW moth is (Z,Z)-11,13-hexdecadienal, an aldehyde component from the female-produced sex pheromone.6-8 PMID:22588282

Standardization of a fluconazole bioassay and correlation of results with those obtained by high-pressure liquid chromatography.

PubMed Central

Rex, J H; Hanson, L H; Amantea, M A; Stevens, D A; Bennett, J E

1991-01-01

An improved bioassay for fluconazole was developed. This assay is sensitive in the clinically relevant range (2 to 40 micrograms/ml) and analyzes plasma, serum, and cerebrospinal fluid specimens; bioassay results correlate with results obtained by high-pressure liquid chromatography (HPLC). Bioassay and HPLC analyses of spiked plasma, serum, and cerebrospinal fluid samples (run as unknowns) gave good agreement with expected values. Analysis of specimens from patients gave equivalent results by both HPLC and bioassay. HPLC had a lower within-run coefficient of variation (less than 2.5% for HPLC versus less than 11% for bioassay) and a lower between-run coefficient of variation (less than 5% versus less than 12% for bioassay) and was more sensitive (lower limit of detection, 0.1 micrograms/ml [versus 2 micrograms/ml for bioassay]). The bioassay is, however, sufficiently accurate and sensitive for clinical specimens, and its relative simplicity, low sample volume requirement, and low equipment cost should make it the technique of choice for analysis of routine clinical specimens. PMID:1854166

Evaluation of genotoxic effects of surface waters using a battery of bioassays indicating different mode of action.

PubMed

Han, Yingnan; Li, Na; Oda, Yoshimitsu; Ma, Mei; Rao, Kaifeng; Wang, Zijian; Jin, Wei; Hong, Gang; Li, Zhiguo; Luo, Yi

2016-11-01

With the burgeoning contamination of surface waters threatening human health, the genotoxic effects of surface waters have received much attention. Because mutagenic and carcinogenic compounds in water cause tumors by different mechanisms, a battery of bioassays that each indicate a different mode of action (MOA) is required to evaluate the genotoxic effects of contaminants in water samples. In this study, 15 water samples from two source water reservoirs and surrounding rivers in Shijiazhuang city of China were evaluated for genotoxic effects. Target chemical analyses of 14 genotoxic pollutants were performed according to the Environmental quality standards for surface water of China. Then, the in vitro cytokinesis-block micronucleus (CBMN) assay, based on a high-content screening technique, was used to detect the effect of chromosome damage. The SOS/umu test using strain TA1535/pSK1002 was used to detect effects on SOS repair of gene expression. Additionally, two other strains, NM2009 and NM3009, which are highly sensitive to aromatic amines and nitroarenes, respectively, were used in the SOS/umu test to avoid false negative results. In the water samples, only two of the genotoxic chemicals listed in the water standards were detected in a few samples, with concentrations that were below water quality standards. However, positive results for the CBMN assay were observed in two river samples, and positive results for the induction of umuC gene expression in TA1535/pSK1002 were observed in seven river samples. Moreover, positive results were observed for NM2009 with S9 and NM3009 without S9 in some samples that had negative results using the strain TA1535/pSK1002. Based on the results with NM2009 and NM3009, some unknown or undetected aromatic amines and nitroarenes were likely in the source water reservoirs and the surrounding rivers. Furthermore, these compounds were most likely the causative pollutants for the genotoxic effect of these water samples. Therefore, to identify causative pollutants with harmful biological effects, chemical analyses for the pollutants listed in water quality standards is not sufficient, and single-endpoint bioassays may underestimate adverse effects. Thus, a battery of bioassays based on different MOAs is required for the comprehensive detection of harmful biological effects. In conclusion, for genotoxicity screening of surface waters, the SOS/umu test system by using different strains combined with the CBMN assay was a useful approach. Copyright © 2016 Elsevier Inc. All rights reserved.

Biting Deterrence and Insecticidal Activity of Hydrazide-Hydrazones and Their Corresponding 3-acetyl-2,5-disubstituted-2,3-dihydro-1,3,4-oxadiazoles Against Aedes aegypti

DTIC Science & Technology

2012-09-11

against biting insects and later on new insecticides including pyrethroids have been widely used to control a wide range of insect pests in agriculture and...1 to 20 are shown in Table 1. 2.2 Biological activity 2.2.1 Insects The Ae. aegypti (L.) mosquitoes used in these studies were from a laboratory...sucrose solution. Females (5–9 days old) were selected for bioassays. For larval bioassays, the eggs were hatched 1 day prior to testing, and the

Ecotoxicological assessment of metal-polluted urban soils using bioassays with three soil invertebrates.

PubMed

Santorufo, Lucia; Van Gestel, Cornelis A M; Maisto, Giulia

2012-07-01

This study aimed at assessing the quality of urban soils by integrating chemical and ecotoxicological approaches. Soils from five sites in downtown Naples, Italy, were sampled and characterized for physical-chemical properties and total and water-extractable metal concentrations. Bioassays with Eisenia andrei, Enchytraeus crypticus and Folsomia candida were performed to assess toxicity of the soils, using survival, reproduction and growth as the endpoints. Metal bioaccumulation in the animals was also measured. The properties and metal concentrations of the soils strongly differed. Metal bioaccumulation was related with total metal concentrations in soil and was highest in E. crypticus, which was more sensitive than E. andrei and F. candida. Responses of the three species to the investigated soils seemed due to both metal contamination and soil properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sediment quality criteria: A review with recommendations for developing criteria for the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Driver, C.J.

1994-05-01

Criteria for determining the quality of liver sediment are necessary to ensure that concentrations of contaminants in aquatic systems are within acceptable limits for the protection of aquatic and human life. Such criteria should facilitate decision-making about remediation, handling, and disposal of contaminants. Several approaches to the development of sediment quality criteria (SQC) have been described and include both descriptive and numerical methods. However, no single method measures all impacts at all times to all organisms (U.S. EPA 1992b). The U.S. EPA`s interest is primarily in establishing chemically based, numerical SQC that are applicable nation-wide (Shea 1988). Of the approachesmore » proposed for SQC development, only three are being considered for numerical SQC on a national level. These approaches include an Equilibrium Partitioning Approach, a site-specific method using bioassays (the Apparent Effects Threshold Approach), and an approach similar to EPA`s water quality criteria (Pavlou and Weston 1984). Although national (or even regional) criteria address a number of political, litigative, and engineering needs, some researchers feel that protection of benthic communities require site-specific, biologically based criteria (Baudo et al. 1990). This is particularly true for areas where complex mixtures of contaminants are present in sediments. Other scientifically valid and accepted procedures for freshwater SQC include a background concentration approach, methods using field or spiked bioassays, a screening level concentration approach, the Apparent Effects Threshold Approach, the Sediment Quality Triad, the International Joint Commission Sediment Assessment Strategy, and the National Status and Trends Program Approach. The various sediment assessment approaches are evaluated for application to the Hanford Reach and recommendations for Hanford Site sediment quality criteria are discussed.« less

Development of an in vitro Bioassay for Recombinant Human Erythropoietin (rHuEPO) Based on Proliferative Stimulation of an Erythroid Cell Line and Analysis of Sialic Acid Dependent Microheterogeneity: UT-7 Cell Bioassay.

PubMed

Metta, Manoj Kumar; Malkhed, Vasavi; Tantravahi, Srinivasan; Vuruputuri, Uma; Kunaparaju, Rajkumar

2017-04-01

Determination of biological activity and its comparison with clinical behavior is important in the quality assessment of therapeutic glycoproteins. In vivo studies are usually employed for evaluating bioactivity of these glycomolecules. However, alternative methods are required to simplify the bioassay and avoid ethical issues associated with in vivo studies. Negatively charged sialic acid residues are known to be critical for in vivo bioactivity of rHuEPO. To address this need, we employed the human acute myeloid leukemia cell line UT-7 for the determination of proliferative stimulation induced by rHuEPO. Relative potencies of various intact and sugar-trimmed rHuEPO preparations were estimated using the International Standard for Human r-DNA derived EPO (87/684) as a reference for bioactivity. The cellular response was measured with a multi-channel photometer using a colorimetric microassay, based on the metabolism of the Resazurin sodium by cell viability. For a resourceful probing of physiological features of rHuEPO with significance, we obtained partly or completely desialylated rHuEPO digested by the neuraminidase enzyme without degradation of carbohydrates. Two-fold higher specific activity was shown by asialoerythropoietin in in vitro analysis compared with the sialoerythropoietin. Further, computational studies were also carried out to construct the 3D model of the erythropoietin (EPO) protein structure using standard comparative modeling methods. The quality of the model was validated using Procheck and protein structure analysis (ProSA) server tools. N-glycan units were constructed; moreover, EPO protein was glycosylated at potential glycosylation amino acid residue sites. The method described should be suitable for potency assessments of pharmaceutical formulations of rHuEPO (European Pharmacopeia, 2016).

Increased Risk Proneness or Social Withdrawal? The Effects of Shortened Life Expectancy on the Expression of Rescue Behavior in Workers of the ant Formica cinerea (Hymenoptera: Formicidae).

PubMed

Miler, Krzysztof; Symonowicz, Beata; Godzińska, Ewa J

2017-01-01

In social insects behavioral consequences of shortened life expectancy include, among others, increased risk proneness and social withdrawal. We investigated the impact of experimental shortening of life expectancy of foragers of the ant Formica cinerea achieved by their exposure to carbon dioxide on the expression of rescue behavior, risky pro-social behavior, tested by means of two bioassays during which a single worker (rescuer) was confronted with a nestmate (victim) attacked by a predator (antlion larva capture bioassay) or immobilized by an artificial snare (entrapment bioassay). Efficacy of carbon dioxide poisoning in shortening life expectancy was confirmed by the analysis of ant mortality. Rescue behavior observed during behavioral tests involved digging around the victim, transport of the sand covering the victim, pulling the limbs/antennae/mandibles of the victim, direct attack on the antlion (in antlion larva capture tests), and snare biting (in entrapment tests). The rate of occurrence of rescue behavior was lower in ants with shortened life expectancy, but that effect was significant only in the case of the entrapment bioassay. Similarly, only in the case of the entrapment bioassay ants with shortened life expectancy displayed rescue behavior after a longer latency and devoted less time to that behavior than ants from the control groups. Our results demonstrated that in ant workers shortened life expectancy may lead to reduced propensity for rescue behavior, most probably as an element of the social withdrawal syndrome that had already been described in several studies on behavior of moribund ants and honeybees.

Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera).

PubMed

Pineda-Castellanos, Mónica L; Rodríguez-Segura, Zitlhally; Villalobos, Francisco J; Hernández, Luciano; Lina, Laura; Nuñez-Valdez, M Eugenia

2015-05-13

Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology.

Assessment of sediment contamination by spermiotoxicity and embryotoxicity bioassays with sea urchins (Paracentrotus lividus) and oysters (Crassostrea gigas).

PubMed

Geffard, O; Budzinski, H; Augagneur, S; Seaman, M N; His, E

2001-07-01

Gametes (sperm) and fertilized eggs (embryos) of the Mediterranean sea urchin, Paracentrotus lividus, and the Japanese oyster, Crassostrea gigas, were used to investigate the toxicity of two marine sediments, one polluted by polycyclic aromatic hydrocarbons (PAH) and the other by heavy metals. The sediment samples were freeze-dried for storage, and three different treatments were used for analysis: whole sediment, unfiltered elutriate, and filtered elutriate. The two sediments were toxic to sea urchin spermatozoa but not to oyster spermatozoa, and embryotoxicity was almost always the more sensitive endpoint for toxicity assessment. As a rule, whole sediment was more toxic than the elutriates by nearly two orders of magnitude. With respect to embryotoxicity, the whole sediments and the elutriates of the PAH-contaminated sediment were more toxic to oyster embryos, whereas the elutriates of the sediment polluted by heavy metals had stronger effects on sea urchin embryos. The results confirm that bioassays with Japanese oyster embryos provide a more sensitive appraisal of toxicity in the marine environment than bioassays with other developmental stages. As a whole, Mediterranean sea urchins and Japanese oysters were similar in overall sensitivity and are therefore both equally suited as bioassay organisms, but tests with oysters are more reproducible because of the better performance of the controls.

Failure of interior residual sprays as protection against mosquitoes in military-issued two-man tents.

PubMed

Morrow, Meredith G; Johnson, Richard N; Polanco, Jorge; Claborn, David M

2010-12-01

Most studies on interior (or indoor) residual spraying (IRS) have been targeted on permanent/semipermanent structures. We measured the utility of a portable field bioassay, which can be set up quickly to determine the best chemical repellent or irritant for use as an IRS during an emergency or military situation when displaced persons are temporarily housed in tents. If the bioassay were used over an extended period of time, it would also offer a unique way to monitor vector susceptibility and would be able to determine which chemical is most efficient in individual populations. In total, 2193 mosquitoes belonging to seven species in five genera were collected over the study period. No statistical differences were found between any of the treatments, control, and standard tents utilizing the 4 x 4 Latin square design. Therefore, we conclude that IRS with these tested chemicals in military-issued two-person tents are not effective or significant at stopping mosquito entrance. Further studies on implementation of a portable, field bioassay should include utilizing different mosquito traps in the bioassay and looking at the difference between contact irritants and spatial repellents in different-sized tents, as spatial repellency may be more important in smaller-sized tents.

Abrin Toxicity and Bioavailability after Temperature and pH Treatment.

PubMed

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.

Abrin Toxicity and Bioavailability after Temperature and pH Treatment

PubMed Central

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

2017-01-01

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. PMID:29027937

Chronic bioassays of rainbow trout fry with compounds representative of contaminants in Great Lakes fish

USGS Publications Warehouse

Passino-Reader, Dora R.; Berlin, William H.; Hickey, James P.

1995-01-01

To evaluate the hazard of organic compounds detected in Great Lakes fish by gas chromatography/mass spectrometry, we tested compounds representative of heterocyclic nitrogen compounds, polycyclic aromatic hydrocarbons, and cyclic alkanes and alkenes. Sixty-day bioassays on the effects of nicotine, phenanthrene, pinane, and pinene on the behavior, growth, and survival of rainbow trout fry, Oncorhynchus mykiss, were conducted in a large, constant-flow, temperature-controlled water system. The following 60-day LCSO's were determined (mg/L): nicotine 5.0, phenanthrene 0.2, pinane 0.8, and pinene 1.2. Values of lowest observed effects level (LOEL) and no observed effects level (NOEL) showed that growth was generally as sensitive an endpoint as behavior and was more sensitive than time of swim-up. The 60-day LC50 values for rainbow trout were compared with earlier acute bioassays with Daphnia pulexand rainbow trout and chronic bioassays with D.pulex conducted at the Great Lakes Science Center. Rainbow trout fry were less sensitive than daphnids in all tests, indicating that toxicity tests with daphnids should be protective of salmonid fry for these types of compounds. The results for representative compounds indicate that these classes of compounds should be included in aquatic risk assessments at sites in the Great Lakes.

Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera)

PubMed Central

Pineda-Castellanos, Mónica L.; Rodríguez-Segura, Zitlhally; Villalobos, Francisco J.; Hernández, Luciano; Lina, Laura; Nuñez-Valdez, M. Eugenia

2015-01-01

Serratia marcescens is a Gram negative bacterium (Enterobacteriaceae) often associated with infection of insects. In order to find pathogenic bacteria with the potential to control scarab larvae, several bacterial strains were isolated from the hemocoel of diseased Phyllophaga spp (Coleoptera:Scarabaeidae) larvae collected from cornfields in Mexico. Five isolates were identified as Serratia marcescens by 16S rRNA gene sequencing and biochemical tests. Oral and injection bioassays using healthy Phyllophaga blanchardi larvae fed with the S. marcescens isolates showed different degrees of antifeeding effect and mortality. No insecticidal activity was observed for Spodoptera frugiperda larvae (Lepidoptera: Noctuidae) by oral inoculation. S. marcescens (Sm81) cell-free culture supernatant caused significant antifeeding effect and mortality to P. blanchardi larvae by oral bioassay and also mortality by injection bioassay. Heat treated culture broths lost the ability to cause disease symptoms, suggesting the involvement of proteins in the toxic activity. A protein of 50.2 kDa was purified from the cell-free broth and showed insecticidal activity by injection bioassay towards P. blanchardi. Analysis of the insecticidal protein by tandem- mass spectrometry (LC-MS/MS) showed similarity to a Serralysin-like protein from S. marcescens spp. This insecticidal protein could have applications in agricultural biotechnology. PMID:25984910

Building bio-assays with magnetic particles on a digital microfluidic platform.

PubMed

Kokalj, Tadej; Pérez-Ruiz, Elena; Lammertyn, Jeroen

2015-09-25

Digital microfluidics (DMF) has emerged as a promising liquid handling technology for a variety of applications, demonstrating great potential both in terms of miniaturization and automation. DMF is based on the manipulation of discrete, independently controllable liquid droplets, which makes it highly reconfigurable and reprogrammable. One of its most exclusive advantages, compared to microchannel-based microfluidics, is its ability to precisely handle solid nano- and microsized objects, such as magnetic particles. Magnetic particles have become very popular in the last decade, since their high surface-to-volume ratio and the possibility to magnetically separate them from the matrix make them perfect suitable as a solid support for bio-assay development. The potential of magnetic particles in DMF-based bio-assays has been demonstrated for various applications. In this review we discuss the latest developments of magnetic particle-based DMF bio-assays with the aim to present, identify and analyze the trends in the field. We also discuss the state-of-the art of device integration, current status of commercialization and issues that still need to be addressed. With this paper we intend to stimulate researchers to exploit and unveil the potential of these exciting tools, which will shape the future of modern biochemistry, microbiology and biomedical diagnostics. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparison of the standard WHO susceptibility tests and the CDC bottle bioassay for the determination of insecticide susceptibility in malaria vectors and their correlation with biochemical and molecular biology assays in Benin, West Africa.

PubMed

Aïzoun, Nazaire; Ossè, Razaki; Azondekon, Roseric; Alia, Roland; Oussou, Olivier; Gnanguenon, Virgile; Aikpon, Rock; Padonou, Gil Germain; Akogbéto, Martin

2013-05-20

The detection of insecticide resistance in natural populations of Anopheles vectors is absolutely necessary for malaria control. In the African region, the WHO insecticide susceptibility test is the most common method for assessing resistance status. In order to search for a simple, rapid and more reliable technique in the assessment of insecticide resistance in malaria vectors, we compared the WHO tests with the CDC bottle bioassay in the Ouemé province of southern Benin where insecticide resistance has been widely reported. Larvae and pupae of Anopheles gambiae s.l. mosquitoes were collected from the breeding sites in Ouemé. WHO and CDC susceptibility tests were conducted simultaneously on unfed female mosquitoes aged 2-5 days old. WHO bioassays were performed with impregnated papers of deltamethrin (0.05%) and bendiocarb (0.1%), whereas CDC bioassays were performed with stock solutions of deltamethrin (12.5 μg per bottle) and bendiocarb (12.5 μg per bottle). PCR techniques were used to detect species, Kdr and Ace-1 mutations. CDC biochemical assays using synergists were also conducted to assess the metabolic resistance. A slight decrease in mortality rates was observed with 97.95% and 98.33% obtained from CDC and WHO bioassays respectively in populations of mosquitoes from Adjara and Dangbo. PCR revealed that all specimens tested were Anopheles gambiae s.s. The Kdr mutation was found at high frequency in all populations and both the Kdr mutation and mono-oxygenase enzymes were implicated as mechanisms of pyrethroid resistance in An. gambiae from Misserete. This study emphasizes that both WHO and CDC bioassays give similar results with regards to the susceptibility of mosquitoes to insecticides in southern Benin. There were complementarities between both methods, however, some specificity was noted for each of the two methods used. Both Kdr and metabolic mechanisms were implicated in the resistance.

Brine Shrimp Bioassays: A Useful Technique in Biological Investigations

ERIC Educational Resources Information Center

Rice, Stanley A.; Maness, Ian B.

2004-01-01

A technique to measure the potency of leaf compounds against herbivores with the use of a bioassay is described. Bioassays are useful in classes where students have career plans like medicine in which bioassays can be used as tools for screening plants for possible medicinal potency.

The CompTox Chemistry Dashboard: a community data resource for environmental chemistry.

PubMed

Williams, Antony J; Grulke, Christopher M; Edwards, Jeff; McEachran, Andrew D; Mansouri, Kamel; Baker, Nancy C; Patlewicz, Grace; Shah, Imran; Wambaugh, John F; Judson, Richard S; Richard, Ann M

2017-11-28

Despite an abundance of online databases providing access to chemical data, there is increasing demand for high-quality, structure-curated, open data to meet the various needs of the environmental sciences and computational toxicology communities. The U.S. Environmental Protection Agency's (EPA) web-based CompTox Chemistry Dashboard is addressing these needs by integrating diverse types of relevant domain data through a cheminformatics layer, built upon a database of curated substances linked to chemical structures. These data include physicochemical, environmental fate and transport, exposure, usage, in vivo toxicity, and in vitro bioassay data, surfaced through an integration hub with link-outs to additional EPA data and public domain online resources. Batch searching allows for direct chemical identifier (ID) mapping and downloading of multiple data streams in several different formats. This facilitates fast access to available structure, property, toxicity, and bioassay data for collections of chemicals (hundreds to thousands at a time). Advanced search capabilities are available to support, for example, non-targeted analysis and identification of chemicals using mass spectrometry. The contents of the chemistry database, presently containing ~ 760,000 substances, are available as public domain data for download. The chemistry content underpinning the Dashboard has been aggregated over the past 15 years by both manual and auto-curation techniques within EPA's DSSTox project. DSSTox chemical content is subject to strict quality controls to enforce consistency among chemical substance-structure identifiers, as well as list curation review to ensure accurate linkages of DSSTox substances to chemical lists and associated data. The Dashboard, publicly launched in April 2016, has expanded considerably in content and user traffic over the past year. It is continuously evolving with the growth of DSSTox into high-interest or data-rich domains of interest to EPA, such as chemicals on the Toxic Substances Control Act listing, while providing the user community with a flexible and dynamic web-based platform for integration, processing, visualization and delivery of data and resources. The Dashboard provides support for a broad array of research and regulatory programs across the worldwide community of toxicologists and environmental scientists.

Assessing the fate and effects of nano aluminum oxide in the terrestrial earthworm, Eisenia fetida.

PubMed

Coleman, Jessica G; Johnson, David R; Stanley, Jacob K; Bednar, Anthony J; Weiss, Charles A; Boyd, Robert E; Steevens, Jeffery A

2010-07-01

Nano-sized aluminum is currently being used by the military and commercial industries in many applications including coatings, thermites, and propellants. Due to the potential for wide dispersal in soil systems, we chose to investigate the fate and effects of nano-sized aluminum oxide (Al2O3), the oxidized form of nano aluminum, in a terrestrial organism. The toxicity and bioaccumulation potential of micron-sized (50-200 microm, nominal) and nano-sized (11 nm, nominal) Al2O3 was comparatively assessed through acute and subchronic bioassays using the terrestrial earthworm, Eisenia fetida. Subchronic (28-d) studies were performed exposing E. fetida to nano- and micron-sized Al2O3-spiked soils to assess the effects of long-term exposure. No mortality occurred in subchronic exposures, although reproduction decreased at >or=3,000 mg/kg nano-sized Al2O3 treatments, with higher aluminum body burdens observed at 100 and 300 mg/kg; no reproductive effects were observed in the micron-sized Al2O3 treatments. In addition to toxicity and bioaccumulation bioassays, an acute (48-h) behavioral bioassay was conducted utilizing a soil avoidance wheel in which E. fetida were given a choice of habitat between control, nano-, or micron-sized Al2O3 amended soils. In the soil avoidance bioassays, E. fetida exhibited avoidance behavior toward the highest concentrations of micron- and nano-sized Al2O3 (>5,000 mg/kg) relative to control soils. Results of the present study indicate that nano-sized Al2O3 may impact reproduction and behavior of E. fetida, although at high levels unlikely to be found in the environment. Copyright (c) 2010 SETAC.

Commercial breakfast cereals available in Mexican markets and their contribution in dietary fiber, β-glucans and protein quality by rat bioassays.

PubMed

Falcón-Villa, María R; Barrón-Hoyos, Jesús M; Cinco-Moroyoqui, Francisco J

2014-09-01

The beneficial effect of dietary fiber (DF) consumption has long been recognized. The global economy and open market trade policies have increased the availability of food products in Mexican markets, resulting in a wide variety of ready-to-eat commercial breakfast cereals classified as 'high fiber'. This research was aimed to evaluate the total dietary fiber contents, its fractions (soluble and insoluble) and β-glucan in 13 commercial 'high-fiber' breakfast cereals, as well as to evaluate their protein quality by rat bioassays. Commercial 'high-fiber' breakfast cereals had 7.42-39.82% insoluble dietary fiber, 2.53-12.85% soluble dietary fiber, and 0.45-4.96% β-glucan. These ready-to-eat commercial 'high-fiber' breakfast cereals differed significantly in their total dietary fiber, their soluble and insoluble DF fractions, and also in their β-glucan contents. When supplied as experimental diets, in 14-day rat feeding trials, the 'high-fiber' breakfast cereals showed an adverse effect on the % N digestibility but protein utilization, as measured as net protein ratio (NPR), was not significantly affected. The consumption of these commercial breakfast cereals, especially those made of oats as the basic ingredient, is highly recommended, since these products, being a concentrated source of dietary fiber, do not affect their protein quality.

Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques.

PubMed

Mohammed, Muzaffer; Clement, Travis C; Aslan, Kadir

2014-12-02

In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400-800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72-24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally.

Circular Bioassay Platforms for Applications in Microwave-Accelerated Techniques

PubMed Central

Mohammed, Muzaffer; Clement, Travis C.; Aslan, Kadir

2014-01-01

In this paper, we present the design of four different circular bioassay platforms, which are suitable for homogeneous microwave heating, using theoretical calculations (i.e., COMSOL™ multiphysics software). Circular bioassay platforms are constructed from poly(methyl methacrylate) (PMMA) for optical transparency between 400–800 nm, has multiple sample capacity (12, 16, 19 and 21 wells) and modified with silver nanoparticle films (SNFs) to be used in microwave-accelerated bioassays (MABs). In addition, a small monomode microwave cavity, which can be operated with an external microwave generator (100 W), for use with the bioassay platforms in MABs is also developed. Our design parameters for the circular bioassay platforms and monomode microwave cavity during microwave heating were: (i) temperature profiles, (ii) electric field distributions, (iii) location of the circular bioassay platforms inside the microwave cavity, and (iv) design and number of wells on the circular bioassay platforms. We have also carried out additional simulations to assess the use of circular bioassay platforms in a conventional kitchen microwave oven (e.g., 900 W). Our results show that the location of the circular bioassay platforms in the microwave cavity was predicted to have a significant effect on the homogeneous heating of these platforms. The 21-well circular bioassay platform design in our monomode microwave cavity was predicted to offer a homogeneous heating pattern, where inter-well temperature was observed to be in between 23.72–24.13°C and intra-well temperature difference was less than 0.21°C for 60 seconds of microwave heating, which was also verified experimentally. PMID:25568813

Effects of exposure to agricultural drainage ditch water on survivorship, distribution, and abundnance of riffle beetles (Coleoptera: Elmidae) in headwater streams of the Cedar Creek watershed, Indiana

USDA-ARS?s Scientific Manuscript database

Riffle Beetles (Coleoptera: Elmidae) require very good water quality, mature streams with riffle habitat, and high dissolved oxygen content. As such, they prove to be good indicators of ecological health in agricultural headwater streams. We conducted static renewal aquatic bioassays using water fro...

Expansion of DSSTox: Leveraging public data to create a semantic cheminformatics resource with quality annotations for support of U.S. EPA applications. (American Chemical Society)

EPA Science Inventory

The expansion of chemical-bioassay data in the public domain is a boon to science; however, the difficulty in establishing accurate linkages from CAS registry number (CASRN) to structure, or for properly annotating names and synonyms for a particular structure is well known. DSS...

Environmental Quality Technology

DTIC Science & Technology

1992-01-01

34Flowthrough bioassay studies on the effects of antifouling TBT leachates." Tributyltin : Environmental Effects, M. A. Champ and P. F. Seligman, eds...organisms. Evaluating the effects of tributyltin on oysters by using the POMFRET system. NONPOINT $OURCE POLLUTION AQUATIC IMPACT PAHs AJR PETROLEUM...on effects of copper and tributyltin -based antifouling paint leachates." NOSC Technical Report 1060 (June). Henderson, R. S., and S. M. Salazar. 1991

Status of Insecticide Resistance in Papua New Guinea: An Update from Nation-Wide Monitoring of Anopheles Mosquitoes.

PubMed

Koimbu, Gussy; Czeher, Cyrille; Katusele, Michelle; Sakur, Muker; Kilepak, Lemen; Tandrapah, Anthony; Hetzel, Manuel W; Pulford, Justin; Robinson, Leanne; Karl, Stephan

2018-01-01

Insecticide resistance (IR) monitoring is an important component of vector-borne disease control. The last assessment of IR in Papua New Guinea (PNG) was conducted in 2010. Since then, vector populations have been exposed to higher levels of pyrethroids with the continued nation-wide distribution of insecticide-treated nets. Here, we provide an update on phenotypic IR in four highly malaria-endemic areas of PNG. IR against deltamethrin, lambda-cyhalothrin, and dichlorodiphenyltrichloroethane was assessed using World Health Organization bioassays. A total of 108 bioassays for each insecticide were conducted screening 2,290 adult female anopheline mosquitoes. No phenotypic resistance was observed. Bioassay parameters agreed well with those observed in other studies that used the same assays and insecticides. These results indicate that the three tested insecticides are still universally effective in PNG. Continued IR monitoring (every 1-2 years) in PNG is recommended to detect reduced susceptibility early and adjust guidelines to prevent widespread resistance.

Iron Bioavailability Studies of the First Generation of Iron-Biofortified Beans Released in Rwanda.

PubMed

Glahn, Raymond; Tako, Elad; Hart, Jonathan; Haas, Jere; Lung'aho, Mercy; Beebe, Steve

2017-07-21

This paper represents a series of in vitro iron (Fe) bioavailability experiments, Fe content analysis and polyphenolic profile of the first generation of Fe biofortified beans ( Phaseolus vulgaris ) selected for human trials in Rwanda and released to farmers of that region. The objective of the present study was to demonstrate how the Caco-2 cell bioassay for Fe bioavailability can be utilized to assess the nutritional quality of Fe in such varieties and how they may interact with diets and meal plans of experimental studies. Furthermore, experiments were also conducted to directly compare this in vitro approach with specific human absorption studies of these Fe biofortified beans. The results show that other foods consumed with beans, such as rice, can negatively affect Fe bioavailability whereas potato may enhance the Fe absorption when consumed with beans. The results also suggest that the extrinsic labelling approach to measuring human Fe absorption can be flawed and thus provide misleading information. Overall, the results provide evidence that the Caco-2 cell bioassay represents an effective approach to evaluate the nutritional quality of Fe-biofortified beans, both separate from and within a targeted diet or meal plan.

Iron Bioavailability Studies of the First Generation of Iron-Biofortified Beans Released in Rwanda

PubMed Central

Glahn, Raymond; Tako, Elad; Hart, Jonathan; Haas, Jere; Beebe, Steve

2017-01-01

This paper represents a series of in vitro iron (Fe) bioavailability experiments, Fe content analysis and polyphenolic profile of the first generation of Fe biofortified beans (Phaseolus vulgaris) selected for human trials in Rwanda and released to farmers of that region. The objective of the present study was to demonstrate how the Caco-2 cell bioassay for Fe bioavailability can be utilized to assess the nutritional quality of Fe in such varieties and how they may interact with diets and meal plans of experimental studies. Furthermore, experiments were also conducted to directly compare this in vitro approach with specific human absorption studies of these Fe biofortified beans. The results show that other foods consumed with beans, such as rice, can negatively affect Fe bioavailability whereas potato may enhance the Fe absorption when consumed with beans. The results also suggest that the extrinsic labelling approach to measuring human Fe absorption can be flawed and thus provide misleading information. Overall, the results provide evidence that the Caco-2 cell bioassay represents an effective approach to evaluate the nutritional quality of Fe-biofortified beans, both separate from and within a targeted diet or meal plan. PMID:28754026

Toxicity assessment for petroleum-contaminated soil using terrestrial invertebrates and plant bioassays.

PubMed

Hentati, Olfa; Lachhab, Radhia; Ayadi, Mariem; Ksibi, Mohamed

2013-04-01

The assessment of soil quality after a chemical or oil spill and/or remediation effort may be measured by evaluating the toxicity of soil organisms. To enhance our understanding of the soil quality resulting from laboratory and oil field spill remediation, we assessed toxicity levels by using earthworms and springtails testing and plant growth experiments. Total petroleum hydrocarbons (TPH)-contaminated soil samples were collected from an oilfield in Sfax, Tunisia. Two types of bioassays were performed. The first assessed the toxicity of spiked crude oil (API gravity 32) in Organization for Economic Co-operation and Development artificial soil. The second evaluated the habitat function through the avoidance responses of earthworms and springtails and the ability of Avena sativa to grow in TPH-contaminated soils diluted with farmland soil. The EC50 of petroleum-contaminated soil for earthworms was 644 mg of TPH/kg of soil at 14 days, with 67 % of the earthworms dying after 14 days when the TPH content reached 1,000 mg/kg. The average germination rate, calculated 8 days after sowing, varied between 64 and 74 % in low contaminated soils and less than 50 % in highly contaminated soils.

Tradescantia-micronucleus (Trad-MCN) bioassay on clastogenicity of wastewater and in situ monitoring.

PubMed

Ruiz, E F; Rabago, V M; Lecona, S U; Perez, A B; Ma, T H

1992-11-01

The Tradescantia-micronucleus (Trad-MCN) bioassay was used to determine the clastogenicity of wastewater samples collected from the Arena canal which contains effluent from the industrial district Benito Juarez of the city of Queretaro, Mexico. Fifteen wastewater samples which were collected, in most cases, at bi-weekly intervals beginning in September 1986 through February 1988, after a 3-fold dilution were used to treat Tradescantia plant cuttings. The clastogenicity expressed in terms of micronucleus frequencies of treated groups (30 h of treatment without recovery time) was significantly (0.01) higher than that of the tapwater control groups. The Trad-MCN bioassay was also used for in situ monitoring of air pollutants for the clastogenicity at 3 sites near the industrial and residential areas (Flores Magon, Conalep and Bellas Artes) of the city of Queretaro. Fourteen monitoring trips were made to each of the 3 sites at monthly intervals beginning in May 1988 through June 1990. Seasonal variation of micronucleus frequencies was exhibited with the peak clastogenicities shown in May and June 1988, June 1989 and April 1990 at the three sites. Micronucleus frequencies of all the exposed groups at the Conalep site, a predominantly industrial area, were markedly higher than that of the laboratory control groups throughout the 2-year period.

Microtox(TM) characterization of foundry sand residuals

USGS Publications Warehouse

Bastian, K.C.; Alleman, J.E.

1998-01-01

Although foundry residuals, consisting mostly of waste Sands, represent a potentially attractive, high-volume resource for beneficial reuse applications (e.g. highway embankment construction), prospective end users are understandably concerned about unforeseen liabilities stemming from the use of these residuals. This paper, therefore, focuses on the innovative use of a microbial bioassay as a means of developing a characterization of environmental suitability extending beyond the analytical coverage already provided by mandated chemical-specific tests (i.e., TCLP, etc.). Microtox(TM) bioassays were conducted on leachates derived from residuals obtained at a wide range of facilities, including: 11 gray and ductile iron foundries plus one each steel and aluminum foundries. In addition, virgin sand samples were used to establish a relative 'natural' benchmark against which the waste foundry sands could then be compared in terms of their apparent quality. These bioassay tests were able to effectively 'fingerprint' those residuals whose bioassay behavior was comparable to that of virgin materials. In fact, the majority of gray and ductile iron foundry residuals tested during this reported study elicited Microtox(TM) response levels which fell within or below the virgin sand response range, consequently providing another quantifiable layer of Support for this industry's claim that their sands are 'cleaner than dirt.' However, negative Microtox(TM) responses beyond that of the virgin sands were observed with a number of foundry samples (i.e. four of the 11 gray or ductile iron sands plus both non-iron sands). Therefore, the latter results would suggest that these latter residuals be excluded from beneficial reuse for the immediate future, at least until the cause and nature of this negative response has been further identified.

Attraction of subterranean termites (Isoptera) to carbon dioxide.

PubMed

Bernklau, Elisa Jo; Fromm, Erich A; Judd, Timothy M; Bjostad, Louis B

2005-04-01

Subterranean termites, Reticulitermes spp., were attracted to carbon dioxide (CO2) in laboratory and field tests. In behavioral bioassays, Reticulitermes flavipes (Kollar), Reticulitermes tibialis Banks, and Reticulitermes virginicus Banks were attracted to CO2 concentrations between 5 and 50 mmol/mol. In further bioassays, R. tibialis and R. virginicus were attracted to the headspace from polyisocyanurate construction foam that contained 10-12 mmol/mol CO2. In soil bioassays in the laboratory, more termites foraged in chambers containing CO2-generating formulations than in unbaited control chambers. In field tests, stations containing CO2-generating baits attracted R. tibialis away from wooden fence posts at rangeland sites in Colorado. For all of the CO2 formulations tested, termites foraged in significantly more bait stations at treatment fenceposts than in bait stations at the control fenceposts. By the end of the 8-wk study, the number of bait stations located by termites at treatment fenceposts ranged from 40 to 90%. At control fenceposts, termites foraged in only a single station and the one positive station was not located by termites until week 5 of the study. At treatment fenceposts, termites foraged equally in active stations (containing a CO2-generating bait) and passive stations (with no CO2-generating bait), indicating that bait stations may benefit passively from a proximal CO2 source in the soil. CO2 used as an attractant in current baiting systems could improve their effectiveness by allowing earlier exposure of termites to an insecticide.

Novel nanoscale pheromone dispenser for more accurate evaluation of Grapholita molesta (Lepidoptera: Tortricidae) attract-and-kill strategies in the laboratory.

PubMed

Czarnobai De Jorge, Bruna; Bisotto-de-Oliveira, Ricardo; Pereira, Cláudio Nunes; Sant'Ana, Josué

2017-09-01

Nanotechnology has recently allowed the production of formulations for controlled release of active ingredients. In the present study, the electrospinning technique was used to produce nanoscale dispensers for attract-and-kill strategies. Non-woven nanofibres containing insecticide (cypermethrin) and (E)-8,(Z)-8-dodecenyl acetate and (Z)-8-dodecanol (0.87 mg L -1 ), the main components of Grapholita molesta (Lepidoptera: Tortricidae) (Busck) pheromone, were evaluated in laboratory experiments. Male electroantennographic (EAG) responses and mortality (tarsal-contact and attract-and-kill behavioural cages) bioassays were performed for nanofibres (with and without insecticide) exposed for different periods (21, 42, 63 and 84 days) in controlled and non-exposed conditions. There were no significant differences in G. molesta male EAG responses based on the time of exposure within treatments. Nanofibres with pheromone only and with pheromone plus insecticide elicited equal EAG responses. Mortality in tarsal-contact bioassays was greater than 87% after exposure for 84 days. In the attract-and-kill bioassays, mortality ranged from 28.4 to 56.6%, although no difference was observed on insect mortalities over time (24, 48 and 72 h). Incorporation of cypermethrin in nanofibres did not interfere with G. molesta attractiveness. Both aspects of the strategy, the attractant and killing effects, were recorded using innovative nanofibres, and long-term effects suggest a controlled release of pheromone and insecticide. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Responses of lone star tick (acari: ixodidae) nymphs to the repellent deet applied in acetone and ethanol solutions in vitro bioassays

USDA-ARS?s Scientific Manuscript database

Behavioral bioassays remain a standard tool in the discovery, development, and registration of repellents. Although tick repellent bioassays tend to be rather uncomplicated, several factors can influence their outcomes. Typically repellent bioassays use a solvent, such as acetone or ethanol, to disp...

A yeast bioassay for direct measurement of thyroid hormone disrupting effects in water without sample extraction, concentration, or sterilization.

PubMed

Li, Jian; Ren, Shujuan; Han, Shaolun; Li, Na

2014-04-01

The present study introduces an improved yeast bioassay for rapid yet sensitive evaluation of thyroid hormone disruption at the level of thyroid receptor (TR) in environmental water samples. This assay does not require water sample preparation and thus requires very little hands-on time. Based on different β-galactosidase substrates, two modified bioassays, a colorimetric bioassay and a chemiluminescent bioassay, were developed. The compounds tested included the known thyroid hormone 3,3',5-triiodo-l-thyronine (T3), the specific TR antagonist amiodarone hydrochloride (AH) and phthalate esters (PAEs), which potentially disrupt thyroid hormone signaling. The EC50 values for T3 were similar to those previously obtained using a 96-well plate bioassay. TR antagonism by AH was studied in the presence of 2.5 × 10(-7)M T3, and the concentration producing 20% of the maximum effect (RIC20) for AH was 3.1 × 10(-7)M and 7.8 × 10(-9)M for the colorimetric bioassay and chemiluminescent bioassay, respectively. None of the tested PAEs induced β-galactosidase expression, but diethylhexyl phthalate, benzyl butyl phthalate and dibutyl phthalate demonstrated TR antagonism. Furthermore, water samples collected from Guanting reservoir in Beijing were evaluated. Although TR agonism was not observed, antagonism was detected in all water samples and is expressed as AH equivalents. The toxicology equivalent quantity values obtained by the chemiluminescent bioassay ranged from 21.2 ± 1.6 to 313.9 ± 28.8 μg L(-1) AH, and similar values were obtained for the colorimetric bioassay. The present study shows that the modified yeast bioassay can be used as a valuable tool for quantification of thyroid hormone disrupting effects in environmental water samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

A preliminary evaluation of the potential of Beauveria bassiana for bed bug control.

PubMed

Barbarin, Alexis M; Jenkins, Nina E; Rajotte, Edwin G; Thomas, Matthew B

2012-09-15

Residual biopesticide treatments of Beauveria bassiana were tested against the bed bug Cimex lectularius. An oil formulation of conidia was applied to different substrates. Bed bugs were exposed for 1 h, transferred to an unsprayed environment and monitored for mortality. Separate bioassays evaluated the effect of bed bug strain, sex, life stage, and exposure substrate on mortality. Rapid mortality was observed in all bioassays, with bed bugs exposed to treated jersey knit cotton dying most rapidly. A further assay demonstrated efficient autodissemination of conidia from exposed bed bugs to unexposed bed bugs within artificial harborages. Copyright © 2012 Elsevier Inc. All rights reserved.

Uncovering cyanobacteria ecological networks from long-term monitoring data using Granger causality analysis

NASA Astrophysics Data System (ADS)

Nelson, N.; Munoz-Carpena, R.; Kaplan, D. A.; Phlips, E. J.

2016-12-01

In many aquatic systems, cyanobacteria form harmful blooms capable of producing toxins, prompting hypoxia, and/or introducing internal nitrogen loads via N2-fixation, among other impacts. Traditionally, system-specific cyanobacteria drivers are determined by performing controlled experiments and bioassays, but these approaches may neglect the influences of confounding factors and over assign importance to only those variables considered within experimental designs. For example, a bioassay may conclude that the cyanobacteria in a particular system are limited by phosphorus, but will not explicitly take into account the role of flow as a control on phosphorus delivery. This study aims to address this analytical gap by identifying environmental controls on cyanobacteria while removing the effects of potentially confounding variables. In the present work, we evaluate a unique long-term (17 year) dataset composed of monthly observations of phytoplankton and zooplankton species abundances, water quality constituents, and hydrologic variables from Lake George, a flow-through lake of the St. Johns River (FL) impacted by cyanobacterial blooms. Using conditional Granger causality analysis, a time series approach that infers causality while removing the effects of confounding variables, data were evaluated to identify biological and physicochemical drivers of cyanobacteria. The analysis was performed for three response variable sets: total cyanobacteria, N2-fixers and non-fixers, and cyanobacteria genera. Results depicted increasing levels of ecological complexity as subdivisions of cyanobacteria became more detailed; whereas causal networks produced from analyses of cyanobacteria genera provided novel insights relevant for management (i.e. nutrients, flow), the total cyanobacteria network only included water temperature as a significant driver. Additionally, the more detailed cyanobacteria subdivisions uncovered that N2-fixation was only evident with the earliest season bloomer, thus indicating that early season bloomers may be facilitating later-season growth. These findings highlight the importance of detailed monitoring efforts, and indicate that greater emphasis needs to be placed on the role of early bloomers in phytoplankton dynamics, as it relates to management efforts.

Bioassays with terrestrial and aquatic species as monitoring tools of hydrocarbon degradation.

PubMed

Bori, Jaume; Vallès, Bettina; Ortega, Lina; Riva, Maria Carme

2016-09-01

In this study chemical analyses and ecotoxicity tests were applied for the assessment of a heavily hydrocarbon-contaminated soil prior and after the application of a remediation procedure that consisted in the stimulation of soil autochthonous populations of hydrocarbon degraders in static-ventilated biopiles. Terrestrial bioassays were applied in mixtures of test soils and artificial control soil and studied the survival and reproduction of Eisenia fetida and the avoidance response of E. fetida and Folsomia candida. Effects on aquatic organisms were studied by means of acute tests with Vibrio fischeri, Raphidocelis subcapitata, and Daphnia magna performed on aqueous elutriates from test soils. The bioremediation procedure led to a significant reduction in the concentration of hydrocarbons (from 34264 to 3074 mg kg(-1), i.e., 91 % decrease) and toxicity although bioassays were not able to report a percentage decrease of toxicity as high as the percentage reduction. Sublethal tests proved the most sensitive terrestrial bioassays and avoidance tests with earthworms and springtails showed potential as monitoring tools of hydrocarbon remediation due to their high sensitivity and short duration. The concentrations of hydrocarbons in water extracts from test soils were 130 and 100 μg L(-1) before and after remediation, respectively. Similarly to terrestrial tests, most aquatic bioassays detected a significant reduction in toxicity, which was almost negligible at the end of the treatment. D. magna survival was the most affected by soil elutriates although toxicity to the crustacean was associated to the salinity of the samples rather than to the concentration of hydrocarbons. Ecotoxicity tests with aqueous soil elutriates proved less relevant in the assessment of hydrocarbon-contaminated soils due to the low hydrosolubility of hydrocarbons and the influence of the physicochemical parameters of the aquatic medium.

Isolation and Characterization of Burkholderia rinojensis sp. nov., a Non-Burkholderia cepacia Complex Soil Bacterium with Insecticidal and Miticidal Activities

PubMed Central

Fernandez, Lorena E.; Koivunen, Marja; Yang, April; Flor-Weiler, Lina; Marrone, Pamela G.

2013-01-01

Isolate A396, a bacterium isolated from a Japanese soil sample demonstrated strong insecticidal and miticidal activities in laboratory bioassays. The isolate was characterized through biochemical methods, fatty acid methyl ester (FAME) analysis, sequencing of 16S rRNA, multilocus sequence typing and analysis, and DNA-DNA hybridization. FAME analysis matched A396 to Burkholderia cenocepacia, but this result was not confirmed by 16S rRNA or DNA-DNA hybridization. 16S rRNA sequencing indicated closest matches with B. glumae and B. plantarii. DNA-DNA hybridization experiments with B. plantarii, B. glumae, B. multivorans, and B. cenocepacia confirmed the low genetic similarity (11.5 to 37.4%) with known members of the genus. PCR-based screening showed that A396 lacks markers associated with members of the B. cepacia complex. Bioassay results indicated two mechanisms of action: through ingestion and contact. The isolate effectively controlled beet armyworms (Spodoptera exigua; BAW) and two-spotted spider mites (Tetranychus urticae; TSSM). In diet overlay bioassays with BAW, 1% to 4% (vol/vol) dilution of the whole-cell broth caused 97% to 100% mortality 4 days postexposure, and leaf disc treatment bioassays attained 75% ± 22% mortality 3 days postexposure. Contact bioassays led to 50% larval mortality, as well as discoloration, stunting, and failure to molt. TSSM mortality reached 93% in treated leaf discs. Activity was maintained in cell-free supernatants and after heat treatment (60°C for 2 h), indicating that a secondary metabolite or excreted thermostable enzyme might be responsible for the activity. Based on these results, we describe the novel species Burkholderia rinojensis, a good candidate for the development of a biocontrol product against insect and mite pests. PMID:24096416

A rapid chemiluminescent slot blot immunoassay for the detection and quantification of Clostridium botulinum neurotoxin type E, in cultures.

PubMed

Cadieux, Brigitte; Blanchfield, Burke; Smith, James P; Austin, John W

2005-05-01

A simple, rapid, cost-effective in vitro slot blot immunoassay was developed for the detection and quantification of botulinum neurotoxin type E (BoNT/E) in cultures. Culture supernatants of 36 strains of clostridia, including 12 strains of Clostridium botulinum type E, 12 strains of other C. botulinum neurotoxin serotypes, and 12 strains of other clostridial species were tested. Samples containing BoNT/E were detected using affinity-purified polyclonal rabbit antisera prepared against BoNT/E with subsequent detection of secondary antibodies using chemiluminescence. All strains of C. botulinum type E tested positive, while all non C. botulinum type E strains tested negative. The sensitivity of the slot blot immunoassay for detection of BoNT/E was approximately four mouse lethal doses (MLD). The intensity of chemiluminescence was directly correlated with the concentration of BoNT/E up to 128 MLD, allowing quantification of BoNT/E between 4 and 128 MLD. The slot blot immunoassay was compared to the mouse bioassay for detection of BoNT/E using cultures derived from fish samples inoculated with C. botulinum type E, and cultures derived from naturally contaminated environmental samples. A total of 120 primary enrichment cultures derived from fish samples, of which 103 were inoculated with C. botulinum type E, and 17 were uninoculated controls, were assayed. Of the 103 primary enrichment cultures derived from inoculated fish samples, all were positive by mouse bioassay, while 94 were also positive by slot blot immunoassay, resulting in a 7.5% false-negative rate. All 17 primary enrichment cultures derived from the uninoculated fish samples were negative by both mouse bioassay and slot blot immunoassay. A total of twenty-six primary enrichment cultures derived from environmental samples were tested by mouse bioassay and slot blot immunoassay. Of 13 primary enrichment cultures positive by mouse bioassay, 12 were also positive by slot blot immunoassay, resulting in a 3.8% false-negative rate. All 13 primary enrichment cultures that tested negative by mouse bioassay also tested negative by slot blot immunoassay. The slot blot immunoassay could be used routinely as a positive screen for BoNT/E in primary enrichment cultures, and could be used as a replacement for the mouse bioassay for pure cultures.

Combination of Methoprene and Controlled Aeration to Manage Insects in Stored Wheat.

PubMed

Liu, Samuel S; Arthur, Frank H; VanGundy, Douglas; Phillips, Thomas W

2016-06-17

A commercial formulation of the insect growth regulator methoprene was applied to wheat stored in small bins either alone or in combination with controlled aeration of the bins, to lower grain temperature for insect pest management of stored wheat. Grain temperatures were monitored and modified by a computer-controlled thermocouple system that also activated the aeration system at programmed set-points to move cool ambient air through the grain mass to lower grain temperature. Results from sampling insect populations in experimental storage bins along with laboratory mortality bioassays of insects placed on wheat taken from the bins over the course of the storage period showed that methoprene was very effective in controlling infestation by the externally-feeding stored grain insects Plodia interpunctella (Hübner), the Indian meal moth Tribolium castaneum (Herbst), the red flour beetle, Cryptolestes ferrugineus (Stephens), the rusty grain beetle, and also for the internal-feeding pest Rhyzopertha dominica( Fauvel), the lesser grain borer. Methoprene did not give good control of the internal-feeding pest Sitophilus oryzae (L.), the rice weevil. Aeration alone was somewhat effective in suppressing insect population development, while methoprene alone or when combined with aeration greatly enhanced insect control. Commercial grain grading for industry quality standards at the end of the storage period confirmed the impact of insect suppression on maintaining high quality of the stored wheat. This field experiment shows that methoprene combined with aeration to cool grain can be effective for pest management of stored wheat in the southern plains of the United States of America.

Analysis of streptokinase by validated liquid chromatography methods and correlation with an in vitro bioassay.

PubMed

Cardoso, Clóvis Dervil Appratto; Perobelli, Rafaela Ferreira; Xavier, Bruna; Maldaner, Fernanda Pavani Stamm; da Silva, Francielle Santos; Dalmora, Sérgio Luiz

2017-01-01

Reversed-phase and size-exclusion liquid chromatography methods were validated for the assessment of streptokinase. The reversed-phase method was carried out on a Jupiter C 4 column (250 mm × 4.6 mm id) maintained at 25°C. The mobile phase consisted of 50 mM sodium sulfate solution pH 7.0 and methanol (90:10, v/v), run isocratically at a flow rate of 0.8 mL/min. The size-exclusion method was carried out on a Protein KW 802.5 column (300 mm × 8.0 mm id), at 25°C. The mobile phase consisted of 40 mM sodium acetate solution pH 7.0, run isocratically at a flow rate of 1.0 mL/min. Retention times were 19.3 min, and 14.1 min, and calibration curves were linear over the concentration range of 0.25-250 μg/mL (25.75-25 750 IU/mL) (r 2 = 0.9997) and 5-80 μg/mL (515-8240 IU/mL) (r 2 = 0.9996), respectively, for reversed-phase and size exclusion, with detection at 220 and 204 nm. Chromatographic methods were employed in conjunction with the in vitro bioassay for the content/potency assessment of Streptokinase, contributing to improve the quality control and ensure the efficacy of the biotherapeutic. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

2-Ethylhexanol; Final Test Rule

EPA Pesticide Factsheets

EPA is issuing a final test rule, under section 4 of the Toxic Substances Control Act (TSCA), requiring manufacturers and processors of 2-ethylhexanol (EH: CAS No. 104-76-7) to conduct a 2-year oncogenicity bioassay.

9 CFR 147.16 - Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment).

Code of Federal Regulations, 2014 CFR

2014-01-01

... mycoplasma reactors by in vivo bio-assay (enrichment). 147.16 Section 147.16 Animals and Animal Products... the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). This procedure has been shown... publications: (a) Bigland, C. H. and A. J. DaMassa, “A Bio-Assay for Mycoplasma Gallisepticum.” In: United...

9 CFR 147.16 - Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment).

Code of Federal Regulations, 2012 CFR

2012-01-01

... mycoplasma reactors by in vivo bio-assay (enrichment). 147.16 Section 147.16 Animals and Animal Products... the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). This procedure has been shown... publications: (a) Bigland, C. H. and A. J. DaMassa, “A Bio-Assay for Mycoplasma Gallisepticum.” In: United...

9 CFR 147.16 - Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment).

Code of Federal Regulations, 2013 CFR

2013-01-01

... mycoplasma reactors by in vivo bio-assay (enrichment). 147.16 Section 147.16 Animals and Animal Products... the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). This procedure has been shown... publications: (a) Bigland, C. H. and A. J. DaMassa, “A Bio-Assay for Mycoplasma Gallisepticum.” In: United...

Using lone star ticks, Amblyomma americanum (Acari: Ixodidae) in in vitro laboratory bioassays of repellents: dimensions, duration, and variability

USDA-ARS?s Scientific Manuscript database

The in vitro bioassay is an important tool in repellent discovery and development, with a variety of bioassays used in recent years. Several factors, such as the dimensions and configuration of test surfaces and duration of tick exposure, can influence the outcome of bioassays. We tested two tick re...

9 CFR 147.16 - Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment).

Code of Federal Regulations, 2010 CFR

2010-01-01

... mycoplasma reactors by in vivo bio-assay (enrichment). 147.16 Section 147.16 Animals and Animal Products... the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). This procedure has been shown... publications: (a) Bigland, C. H. and A. J. DaMassa, “A Bio-Assay for Mycoplasma Gallisepticum.” In: United...

The use of Tradescantia and Vicia faba bioassays for the in situ detection of mutagens in an aquatic environment.

PubMed

Grant, W F; Lee, H G; Logan, D M; Salamone, M F

1992-11-01

Tests have shown plant bioassays to be excellent for mutagenicity studies. Most studies with plant bioassays, however, have been carried out either in the laboratory, or if, in situ, as monitors of atmospheric contaminants. The primary purpose of this study was to assess the utility of in situ plant mutagenicity bioassays in monitoring water contaminants. The assay systems tested were the Tradescantia stamen hair and micronucleus assays for the detection of gene mutations and chromosomal aberrations respectively, and the Vicia faba bioassay system which detects chromosomal aberrations in root tips. The assays were used to test the effluent from a pulp and paper mill located on the north shore of Lake Superior. Assays were performed in a creek containing raw effluent and in the bay of Lake Superior into which the creek emptied. All in situ treatments were carried out for 24 h. The effluent from the creek was heavy with pulp and debris which coated the plant cuttings and the Vicia faba seedlings and may have restricted the uptake from the effluent. In the creek, at test sites 11.5 km from the source, the effluent was toxic to the Vicia faba roots as evidenced by a reduction in the mitotic index. The data for the Tradescantia stamen hair assay in the creek were equivocal. The cuttings from the creek test sites and the air and water control sites appeared to have undergone a physiological delay. Within a day or two after the return to the laboratory, that is 6-8 days after testing, flowering almost ceased and did not fully resume until about day 35. This reduction in flowering was particularly severe with the cuttings from the effluent and air control sites, making it very difficult to interpret the results. In contrast, the Tradescantia micronucleus and Vicia faba chromosomal aberration data were unequivocal; each produced positive responses at both test sites relative to the air and water controls. The results obtained for the bay sites with all 3 assays were in agreement. In that section of the bay visibly contaminated by the creek effluent, increases in stamen hair mutants, micronuclei, and chromosome aberrations were measured. In general, there was a considerable reduction in the number of mutant events observed for the water samples brought back from the test sites and tested in the laboratory.(ABSTRACT TRUNCATED AT 400 WORDS)

Laboratory and Field Evaluations of Two Bacillus thuringiensis Formulations, Novodor and Raven, for Control of Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae)

Treesearch

David R. Coyle; Joel D. McMillin; Steven C. Krause; Elwood R. Hart

2000-01-01

Laboratory and field experiments were conducted to determine the efficacy of two Bacillus thuringiensis Berliner formulations, Novodor and Raven, for controlling cottonwood leaf beetle, Chrysomela scripta F. (Coleoptera: Chrysomelidae). In laboratory bioassays, larvae or adults were added to petri dishes containing ...

Erynia radicans as a mycoinsecticide for spruce budworm control

Treesearch

Richard S. Soper

1985-01-01

The entomopahtogenic fungus Erynia radicans, has been under investigation for several years as a possible alternative to chemical control of the eastern spruce budworm. A commercial production method has been developed which allows the formulation of this pathogen as a mycoinsecticide. A standardized bioassay method was used to select strain RS141 as...

Accuracy of a Mouse Bioassay for the Diagnosis of Botulism in Horses.

PubMed

Johnson, A L; McAdams-Gallagher, S C; Aceto, H

2016-07-01

The laboratory diagnosis of botulism in horses traditionally has relied upon the mouse bioassay (MBA). The accuracy of this test for the diagnosis of botulism in horses is unknown. Our goal was to determine the sensitivity, specificity, positive predictive value, and negative predictive value of the MBA on laboratory-processed fecal and gastrointestinal samples for foals and adult horses. Cases included all horses with a final clinical diagnosis of botulism that were admitted between 1986 and 2011 and had MBA testing performed. Controls included horses without botulism that were admitted during the same time period and had MBA testing performed. Retrospective study. Horses suspected of having botulism had fecal or (less commonly) gastrointestinal content samples tested using MBA. For every hospitalized botulism suspect, control samples were obtained from ≥1 additional hospitalized horses not suspected to have botulism. One hundred and twenty-nine adult horses and 253 adult controls were identified. Overall sensitivity of the MBA was only 32% but specificity was 97%. Forty-three foal cases and 21 foal controls were evaluated; sensitivity of the MBA was 53% and specificity was 100%. Positive predictive value was substantially higher (100% for foals and 89% for adults) than negative predictive value (51% for foals and 67% for adults). Mouse bioassay has low sensitivity but high specificity for the diagnosis of botulism in horses. Positive results are highly suggestive of botulism but negative results do not exclude the diagnosis. Unaffected horses and foals rarely shed C. botulinum in their feces. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Assessing Insecticide Susceptibility of Laboratory Lutzomyia longipalpis and Phlebotomus papatasi Sand Flies (Diptera: Psychodidae: Phlebotominae)

PubMed Central

Denlinger, David S.; Lozano-Fuentes, Saul; Lawyer, Phillip G.; Black, William C.; Bernhardt, Scott A.

2015-01-01

Chemical insecticides are effective for controlling Lutzomyia and Phlebotomus sand fly (Diptera: Psychodidae) vectors of Leishmania parasites. However, repeated use of certain insecticides has led to tolerance and resistance. The objective of this study was to determine lethal concentrations (LCs) and lethal exposure times (LTs) to assess levels of susceptibility of laboratory Lutzomyia longipalpis (Lutz and Nieva) and Phlebotomus papatasi (Scopoli) to 10 insecticides using a modified version of the World Health Organization (WHO) exposure kit assay and Centers for Disease Control and Prevention (CDC) bottle bioassay. Sand flies were exposed to insecticides coated on the interior of 0.5-gallon and 1,000-ml glass bottles. Following exposure, the flies were allowed to recover for 24 h, after which mortality was recorded. From dose–response survival curves for L. longipalpis and P. papatasi generated with the QCal software, LCs causing 50, 90, and 95% mortality were determined for each insecticide. The LCs and LTs from this study will be useful as baseline reference points for future studies using the CDC bottle bioassays to assess insecticide susceptibility of sand fly populations in the field. There is a need for a larger repository of sand fly insecticide susceptibility data from the CDC bottle bioassays, including a range of LCs and LTs for more sand fly species with more insecticides. Such a repository would be a valuable tool for vector management. PMID:26336231

Profiling Animal Toxicants by Automatically Mining Public Bioassay Data: A Big Data Approach for Computational Toxicology

PubMed Central

Zhang, Jun; Hsieh, Jui-Hua; Zhu, Hao

2014-01-01

In vitro bioassays have been developed and are currently being evaluated as potential alternatives to traditional animal toxicity models. Already, the progress of high throughput screening techniques has resulted in an enormous amount of publicly available bioassay data having been generated for a large collection of compounds. When a compound is tested using a collection of various bioassays, all the testing results can be considered as providing a unique bio-profile for this compound, which records the responses induced when the compound interacts with different cellular systems or biological targets. Profiling compounds of environmental or pharmaceutical interest using useful toxicity bioassay data is a promising method to study complex animal toxicity. In this study, we developed an automatic virtual profiling tool to evaluate potential animal toxicants. First, we automatically acquired all PubChem bioassay data for a set of 4,841 compounds with publicly available rat acute toxicity results. Next, we developed a scoring system to evaluate the relevance between these extracted bioassays and animal acute toxicity. Finally, the top ranked bioassays were selected to profile the compounds of interest. The resulting response profiles proved to be useful to prioritize untested compounds for their animal toxicity potentials and form a potential in vitro toxicity testing panel. The protocol developed in this study could be combined with structure-activity approaches and used to explore additional publicly available bioassay datasets for modeling a broader range of animal toxicities. PMID:24950175

Profiling animal toxicants by automatically mining public bioassay data: a big data approach for computational toxicology.

PubMed

Zhang, Jun; Hsieh, Jui-Hua; Zhu, Hao

2014-01-01

In vitro bioassays have been developed and are currently being evaluated as potential alternatives to traditional animal toxicity models. Already, the progress of high throughput screening techniques has resulted in an enormous amount of publicly available bioassay data having been generated for a large collection of compounds. When a compound is tested using a collection of various bioassays, all the testing results can be considered as providing a unique bio-profile for this compound, which records the responses induced when the compound interacts with different cellular systems or biological targets. Profiling compounds of environmental or pharmaceutical interest using useful toxicity bioassay data is a promising method to study complex animal toxicity. In this study, we developed an automatic virtual profiling tool to evaluate potential animal toxicants. First, we automatically acquired all PubChem bioassay data for a set of 4,841 compounds with publicly available rat acute toxicity results. Next, we developed a scoring system to evaluate the relevance between these extracted bioassays and animal acute toxicity. Finally, the top ranked bioassays were selected to profile the compounds of interest. The resulting response profiles proved to be useful to prioritize untested compounds for their animal toxicity potentials and form a potential in vitro toxicity testing panel. The protocol developed in this study could be combined with structure-activity approaches and used to explore additional publicly available bioassay datasets for modeling a broader range of animal toxicities.

Evaluation of a combined macrophyte-epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA.

PubMed

Ray, Andrew M; Mebane, Christopher A; Raben, Flint; Irvine, Kathryn M; Marcarelli, Amy M

2014-07-01

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte-epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte-epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

The use of Ampelisca abdita growth rate as an indicator of sediment quality

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weston, D.P.; Thompson, B.

1995-12-31

Acute lethal bioassays with amphipod crustaceans are routinely used to assess toxicity of bulk sediments. A study within the San Francisco Bay Regional Monitoring Program (RMP) is in progress to develop a chronic bioassay with the amphipod Ampelisca abdita, measuring both survivorship and growth rates. This approach is attractive because depression of growth rate is likely to be a more sensitive indicator of toxic effects than acute lethality, and natural populations of A. abdita exist throughout the Bay. Spiked sediment bioassays, using cadmium and crude oil, were used to demonstrate the relative sensitivity of the standard 10-day lethal test vs.more » the 30-day growth test. Sediments were also collected from 9 sites throughout the Bay, ranging from areas adjacent to municipal wastewater discharges to areas distant from known point source inputs. These samples were then split, and used for side-by-side comparison of acute (lethal) and chronic (growth) toxicity tests. Survivorship exceeded 90% in all tests, including those sediments collected nearest the wastewater outfalls. Growth rates were contrasted among the various treatments to examine the utility of this end point in discriminating the outfall sites. Data on the spatial distribution, abundance, and size-frequency distribution of native populations was examined within the context of using growth rate as an indicator of toxic effects in natural populations as well.« less

Evaluation of a combined macrophyte–epiphyte bioassay for assessing nutrient enrichment in the Portneuf River, Idaho, USA

USGS Publications Warehouse

Ray, Andrew M.; Mebane, Christopher A.; Raben, Flint; Irvine, Kathryn M.; Marcarelli, Amy M.

2014-01-01

We describe and evaluate a laboratory bioassay that uses Lemna minor L. and attached epiphytes to characterize the status of ambient and nutrient-enriched water from the Portneuf River, Idaho. Specifically, we measured morphological (number of fronds, longest surface axis, and root length) and population-level (number of plants and dry mass) responses of L. minor and community-level (ash-free dry mass [AFDM] and chlorophyll a [Chl a]) responses of epiphytes to nutrient enrichment. Overall, measures of macrophyte biomass and abundance increased with increasing concentrations of dissolved phosphorus (P) and responded more predictably to nutrient enrichment than morphological measures. Epiphyte AFDM and Chl a were also greatest in P-enriched water; enrichments of N alone produced no measurable epiphytic response. The epiphyte biomass response did not directly mirror macrophyte biomass responses, illustrating the value of a combined macrophyte–epiphyte assay to more fully evaluate nutrient management strategies. Finally, the most P-enriched waters not only supported greater standing stocks of macrophyte and epiphytes but also had significantly higher water column dissolved oxygen and dissolved organic carbon concentrations and a lower pH. Advantages of this macrophyte–epiphyte bioassay over more traditional single-species assays include the use of a more realistic level of biological organization, a relatively short assay schedule (~10 days), and the inclusion of multiple biological response and water-quality measures.

EPA DSSTox and ToxCast Project Updates: Generating New ...

EPA Pesticide Factsheets

EPA’s National Center for Computational Toxicology is generating data and capabilities to support a new paradigm for toxicity screening and prediction. The DSSTox project is improving public access to quality structure-annotated chemical toxicity information in less summarized forms than traditionally employed in SAR modeling, and in ways that facilitate data-mining and data read-across. The DSSTox Structure-Browser provides structure searchability across the full published DSSTox toxicity-related inventory, enables linkages to and from previously isolated toxicity data resources (soon to include public microarray resources GEO, ArrayExpress, and CEBS), and provides link-outs to cross-indexed public resources such as PubChem, ChemSpider, and ACToR. The published DSSTox inventory and bioassay information also have been integrated into PubChem allowing a user to take full advantage of PubChem structure-activity and bioassay clustering features. Phase I of the ToxCastTM project has generated high-throughput screening (HTS) data from several hundred biochemical and cell-based assays for a set of 320 chemicals, mostly pesticide actives, with rich toxicology profiles. DSSTox and ACToR are providing the primary cheminformatics support for ToxCastTM and collaborative efforts with the National Toxicology Program’s HTS Program and the NIH Chemical Genomics Center. DSSTox will also be a primary vehicle for publishing ToxCastTM ToxRef summarized bioassay data for use

Understanding bioavailability and toxicity of sediment-associated contaminants by combining passive sampling with in vitro bioassays in an urban river catchment.

PubMed

Li, Juan-Ying; Tang, Janet Yat Man; Jin, Ling; Escher, Beate I

2013-12-01

Bioavailable and bioaccessible fractions of sediment-associated contaminants are considered as better dose metrics for sediment-quality assessment than total concentrations. The authors applied exhaustive solvent extraction and nondepletive equilibrium sampling techniques to sediment samples collected along the Brisbane River in South East Queensland, Australia, which range from pristine environments to urban and industry-impacted areas. The wide range of chemicals expected prevents comprehensive chemical analysis, but a battery of cell-based bioassays sheds light on mixture effects of chemicals in relation to various modes of toxic action. Toxic effects were expressed as bioanalytical equivalent concentrations (BEQs) normalized to the organic carbon content of each sediment sample. Bioanalytical equivalent concentrations from exhaustive extraction agreed fairly well with values estimated from polydimethylsiloxane passive sampling extracts via the constant organic carbon to polydimethylsiloxane partition coefficient. Agreement was best for bioassays indicative of photosynthesis inhibition and oxidative stress response and discrepancy within a factor of 3 for the induction of the aryl hydrocarbon receptor. For nonspecific cytotoxicity, BEQ from exhaustive extraction were 1 order of magnitude higher than values from equilibrium sampling, possibly because of coextraction of bioactive natural organic matter that led to an overestimation of toxicity in the exhaustive extracts, which suggests that passive sampling is better suited in combination with bioanalytical assessment than exhaustive extraction. © 2013 SETAC.

Attractants from Bartlett pear for codling moth, Cydia pomonella (L.), larvae

NASA Astrophysics Data System (ADS)

Knight, Alan L.; Light, Douglas M.

2001-08-01

The alkyl ethyl and methyl esters of (2 E,4 Z)-2,4-decadienoic acid found in head-space samples of ripe Bartlett pear ( Pyrus communis L.) stimulated a response from neonate larvae of the codling moth (CM), Cydia pomonella (L.), in both static-air Petri-plate and in upwind Y-tube and straight-tube olfactometer bioassays. In comparison with the known CM neonate attractant, ( E,E)-α-farnesene, ethyl (2 E,4 Z)-2,4-decadienoate was attractive at 10-fold and 1,000-fold lower threshold dosages in the Petri-plate and in the Y-tube bioassays, respectively. Methyl (2 E,4 Z)-2,4-decadienoate was attractive to CM neonates in these bioassays at much higher doses than ethyl (2 E,4 Z)-2,4-decadienoate. Other principal head-space volatiles from ripe pear fruit and pear leaves, including butyl acetate, hexyl acetate, ( Z)-3-hexenyl acetate, and ( E)-β-ocimene, were not attractive to CM neonates. The potential uses of these pear kairomones for monitoring and control of CM in walnuts and apple are discussed.

Allelopathic assessment of selected common weeds in Malaysia

NASA Astrophysics Data System (ADS)

Nurul Ain, M. B.; Nornasuha, Y.; Ismail, B. S.

2016-11-01

A laboratory study was conducted to evaluate the allelopathic potential of eight common weed species in Malaysia, namely, Ageratum conyzoides, Tridax procumbens, Cyperus iria, Fimbristylis miliacea, Eleusine indica, Imperata cylindrica, Lygodium flexuosum and Nephrolepis biserrata of different morphological characteristics (broadleaves, sedges, grasses and ferns). The allelopathic study of these weeds was carried out by testing the leaf litter leachate through the Sandwich method and the volatile compounds of these weeds through the Dish pack method with three replicates for each donor species. The results obtained from both methods were statistically analyzed and the means had converted to percentage growth inhibition to determine the inhibition pattern on the radicle and hypocotyl growth of lettuce seedlings. Among the eight weed species tested, Ageratum conyzoides showed the strongest growth inhibition on lettuce radicle elongation (86%) in the sandwich bioassay compared to the control, followed by Tridax procumbens (71%), which both species being broadleaves weeds. In the dish pack bioassay Lygodium flexuosum (fern) demonstrated maximum inhibition on the growth the radicle and hypocotyl for each different distance from the source well. On the other hand, two weed species exhibited enhanced on the growth radicle and hypocotyl when compared to that of the control in dish pack bioassay. Nephrolepis biserrata and Fimbristylis miliacea were the species that showed the highest growth stimulatory effect. The results presented can be utilized as benchmark information for further research on the elucidation of leachates and volatile chemicals involved in allelopathy in nature. The information can also be helpful in the development of new bioactive chemicals from natural products in weed control strategies.

Acute Toxicity of Fresh and Aged Residues of Pesticides to the Parasitoid Tamarixia radiata and to the HLB-Bacteria Vector Diaphorina citri.

PubMed

Beloti, V H; Alves, G R; Moral, R A; Demétrio, C G B; Yamamoto, P T

2018-06-01

One method for controlling the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama, the vector of the putative causal agent of Huanglongbing, uses the parasitoid Tamarixia radiata (Waterston). However, the general intensive use of insecticides has reduced the numbers of this parasitoid. This study evaluated the effect of the residual action of 24 insecticides on T. radiata and also determined the differential toxicity of insecticides to D. citri and T. radiata, using three bioassays. In the first, when adults of the parasitoid were exposed to residues of the 24 insecticides, ten were considered short-life (class 1), six slightly persistent (class 2), five moderately persistent (class 3), and three insecticides were considered persistent (class 4), under the IOBC/WPRS classification system. The second bioassay evaluated the sublethal concentrations of the persistent insecticides (formetanate, dimethoate, spinosad). Increasing the concentrations of the insecticides increased the number that were classified as persistent. In the third bioassay, evaluation of the differential toxicity of eight insecticides to the ACP and the parasitoid showed that chlorpyrifos and bifenthrin were more harmful to T. radiata. Therefore, these two insecticides are not recommended for application at the time of parasitoid release. Cypermethrin, imidacloprid, and dimethoate caused higher mortality of D. citri and are most often recommended in IPM programs. The choice of an insecticide for the control of citrus pests must be made with care, aiming to preserve the natural enemies in the ecosystem, and thereby contribute to the success of biological control.

In vitro bioanalysis of drinking water from source to tap.

PubMed

Rosenmai, Anna Kjerstine; Lundqvist, Johan; le Godec, Théo; Ohlsson, Åsa; Tröger, Rikard; Hellman, Björn; Oskarsson, Agneta

2018-08-01

The presence of chemical pollutants in sources of drinking water is a key environmental problem threatening public health. Efficient removal of pollutants in drinking water treatment plants (DWTPs) is needed as well as methods for assessment of the total impact of all present chemicals on water quality. In the present study we have analyzed the bioactivity of water samples from source to tap, including effects of various water treatments in a DWTP, using a battery of cell-based bioassays, covering health-relevant endpoints. Reporter gene assays were used to analyze receptor activity of the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), androgen receptor (AR), peroxisome proliferator-activated receptor alpha (PPARα) and induction of oxidative stress by the nuclear factor erythroid 2-related factor 2 (Nrf2). DNA damage was determined by Comet assay. Grab water samples were concentrated by HLB or ENV solid phase extraction and the water samples assayed at a relative enrichment factor of 50. The enrichment procedure did not induce any bioactivity. No bioactivity was detected in Milli-Q water or drinking water control samples. Induction of AhR, ER and Nrf2 activities was revealed in source to tap water samples. No cytotoxicity, PPARα or AR antagonist activity, or DNA damage were observed in any of the water samples. A low AR agonist activity was detected in a few samples of surface water, but not in the samples from the DWTP. The treatment steps at the DWTP, coagulation, granulated activated carbon filtration, UV disinfection and NH 2 Cl dosing had little or no effect on the AhR, Nrf2 and ER bioactivity. However, nanofiltration and passage through the distribution network drastically decreased AhR activity, while the effect on Nrf2 activity was more modest and no apparent effect was observed on ER activity. The present results suggest that bioassays are useful tools for evaluation of the efficiency of different treatment steps in DWTPs in reducing toxic activities. Bioassays of AhR and Nrf2 are useful for screening of effects of a broad range of chemicals in drinking water and ER activity can be monitored with a high sensitivity. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of sediment toxicity and chemical concentrations in the San Diego Bay region, California, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fairey, R.; Roberts, C.; Jacobi, M.

1998-08-01

Sediment quality within San Diego Bay, Mission Bay, and the Tijuana River Estuary of California was investigated as part of an ongoing statewide monitoring effort (Bay Protection and Toxic Cleanup Program). Study objectives were to determine the incidence, spatial patterns, and spatial extent of toxicity in sediments and porewater; the concentration and distribution of potentially toxic anthropogenic chemicals; and the relationships between toxicity and chemical concentrations. Rhepoxynius abronius survival bioassays, grain size, and total organic carbon analyses were performed on 350 sediment samples. Strongylocentrotus purpuratus development bioassays were performed on 164 pore-water samples. Toxicity was demonstrated throughout the San Diegomore » Bay region, with increased incidence and concordance occurring in areas of industrial and shipping activity. Trace metal and trace synthetic organic analyses were performed on 229 samples. Copper, zinc, mercury, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and chlordane were found to exceed ERM (effects range median) or PEL (probable effects level) sediment quality guidelines and were considered the six major chemicals or chemical groups of concern. Statistical analysis of the relationships between amphipod toxicity, bulk phase sediment chemistry, and physical parameters demonstrated few significant linear relationships. Significant differences in chemical levels were found between toxic and nontoxic responses using multivariate and univariate statistics. Potential sources of anthropogenic chemicals were discussed.« less

LC and LD50 values of Bacillus thuringiensis Serovar japonensis strain buibui toxin to Oriental beetle and northern masked chafer larvae (Coleoptera: Scarabaeidae).

PubMed

Mashtoly, Tamer A; El-Zemaity, Mohamed El-Said; Hussien, Mohamed I; Alm, Steven R

2009-10-01

Bacillus thuringiensis serovar japonensis strain Buibui has the potential to be an important control agent for pest scarabs. Bioassays were designed to test B. t. japonensis against two of the major turf and ornamental scarab pests infesting turfgrasses and ornamentals and to serve as a basis for further tests against other scarab pests. LC and LD50 values of B. t. serovarjaponensis strain Buibui toxin and spores were determined by four different bioassays for the oriental beetle, Anomala orientalis (Waterhouse), and northern masked chafer, Cyclocephala borealis Arrow. Oriental beetle larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Kingston, RI [native]), in nonautoclaved soil from where the northern masked chafer larvae were collected (Groton, CT [foreign]), and per os. Northern masked chafer larvae were bioassayed in autoclaved and nonautoclaved soil from where they were collected (Groton, CT [native]), in nonautoclaved soil from where the oriental beetle larvae were collected (Kingston, RI [foreign]) and per os. LC50 values of 3.93 microg toxin/g autoclaved native soil, 1.80 microg toxin/g nonautoclaved native soil, and 0.42 microg toxin/g nonautoclaved foreign soil and an LD50 value of 0.41 microg per os were determined at 14 d forA. orientalis. LC50 values of 588.28 microg toxin/g autoclaved native soil, 155.10 microg toxin/g nonautoclaved native soil, 265.32 microg toxin/g nonautoclaved foreign soil, and LD50 of 5.21 microg per os were determined at 14 d (soils) and 10 d (per os) for C. borealis. There were significant differences in LC50 values for oriental beetles in autoclaved, nonautoclaved native soil and nonautoclaved foreign soil. There were significant differences in LCo values for northern masked chafers in autoclaved and nonautoclaved native soil. B. t. japonensis can be applied now for control of oriental beetles at rates that are economically competitive with synthetic chemicals. If we can determine the component of nonautoclaved soil that enhances the activity of toxin, it may be possible to lower the rates of toxin needed for control to more economical levels for more difficult to control species such as the northern masked chafer.

Evaluation of the mutagenicity and carcinogenicity of motor vehicle emissions in short-term bioassays.

PubMed Central

Lewtas, J

1983-01-01

Incomplete combustion of fuel in motor vehicles results in the emission of submicron carbonaceous particles which, after cooling and dilution, contain varying quantities of extractable organic constituents. These organics are mutagenic in bacteria. Confirmatory bioassays in mammalian cells provide the capability of detecting chromosomal and DNA damage in addition to gene mutations. In order to evaluate the mutagenicity of these organics in mammalian cells, extractable organics from particle emissions from several diesel and gasoline vehicles were compared in a battery of microbial, mammalian cell and in vivo bioassays. The mammalian cell mutagenicity bioassays were selected to detect gene mutations, DNA damage, and chromosomal effects. Carcinogenesis bioassays conducted included short-term assays for oncogenic transformation and skin tumorigenesis. The results in different assay systems are compared both qualitatively and quantitatively. Good quantitative correlations were observed between several mutagenesis and carcinogenesis bioassays for this series of diesel and gasoline emissions. PMID:6186475

The H4IIE cell bioassay as an indicator of dioxin-like chemicals in wildlife and the environment

USGS Publications Warehouse

White, J.J.; Schmitt, C.J.; Tillitt, D. E.

2004-01-01

The H4IIE cell bioassay has proven utility as a screening tool for planar halogenated hydrocarbons (PHHs) and structurally similar chemicals accumulated in organisms from the wild. This bioassay has additional applications in hazard assessment of PHH exposed populations. In this review, the toxicological principles, current protocols, performance criteria, and field applications for the assay are described. The H4IIE cell bioassay has several advantages over the analytical measurement of PHHs in environmental samples, but conclusions from studies can be strengthened when both bioassay and analytical chemistry data are presented together. Often, the bioassay results concur with biological effects in organisms and support direct measures of PHHs. For biomonitoring purposes and prioritization of PHH-contaminated environments, the H4IIE bioassay may be faster and less expensive than analytical measurements. The H4IIE cell bioassay can be used in combination with other biomarkers such as in vivo measurements of CYP1A1 induction to help pinpoint the sources and identities of dioxin-like chemicals. The number of studies that measure H4IIE-derived TCDD-EQs continues to increase, resulting in subtle improvements over time. Further experiments are required to determine if TCDD-EQs derived from mammalian cells are adequate predictors of toxicity to non-mammalian species. The H4IIE cell bioassay has been used in over 300 published studies, and its combination of speed, simplicity, and ability to integrate the effects of complex containment mixtures makes it a valuable addition to hazard assessment and biomonitoring studies.

Monitoring Resistance to Spinosad in the Melon Fly (Bactrocera cucurbitae) in Hawaii and Taiwan

PubMed Central

Hsu, Ju-Chun; Haymer, David S.; Chou, Ming-Yi; Feng, Hai-Tung; Chen, Hsaio-Han; Huang, Yu-Bing; Mau, Ronald F. L.

2012-01-01

Spinosad is a natural insecticide with desirable qualities, and it is widely used as an alternative to organophosphates for control of pests such as the melon fly, Bactrocera cucurbitae (Coquillett). To monitor the potential for development of resistance, information about the current levels of tolerance to spinosad in melon fly populations were established in this study. Spinosad tolerance bioassays were conducted using both topical applications and feeding methods on flies from field populations with extensive exposure to spinosad as well as from collections with little or no prior exposure. Increased levels of resistance were observed in flies from the field populations. Also, higher dosages were generally required to achieve specific levels of mortality using topical applications compared to the feeding method, but these levels were all lower than those used for many organophosphate-based food lures. Our information is important for maintaining effective programs for melon fly management using spinosad. PMID:22629193

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOCmore » and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.« less

Morphological alterations induced by boric acid and fipronil in the midgut of worker honeybee (Apis mellifera L.) larvae : Morphological alterations in the midgut of A. mellifera.

PubMed

da Silva Cruz, Aline; da Silva-Zacarin, Elaine C M; Bueno, Odair C; Malaspina, Osmar

2010-04-01

Morphological alterations, by means of histological and ultrastructural analysis, have been used to determine the effects of boric acid and fipronil on midgut tissues of honeybee worker, Apis mellifera L. larvae. In order to observe possible morphological alterations in the midgut, two groups of bioassays were performed. In the first one, the larvae were chronically treated with different concentrations of boric acid added to the food (1.0, 2.5 and 7.5 mg/g). In the second group, the larvae were fed with diets containing different concentrations of fipronil (0.1 and 1 microg/g) and compared with control groups without these chemical compounds. In the first bioassay, the larvae were collected on day 3 and in the second bioassay on day 4, when the mortality rate obtained in the toxicological bioassay was not very high. The larval midguts were removed and processed for morphological analyses using a light and transmission electron microscopy. We observed cytoplasmic vacuolizations, with the absence of autophagic vacuoles, and chromatinic compacting in most of the cells in the groups treated with pesticides. The morphological alterations were far greater in the larvae treated with boric acid than in the larvae treated with fipronil. Our data suggest that the midgut cell death observed was in response to boric acid and fipronil action. This study significantly improves the understanding of the toxicological effect of these insecticides from the ecotoxicological perspective.

Impact of vineyard pesticides on a beneficial arthropod, Typhlodromus pyri (Acari: Phytoseiidae), in laboratory bioassays.

PubMed

Gadino, Angela N; Walton, Vaughn M; Dreves, Amy J

2011-06-01

Laboratory bioassays were conducted to evaluate the effects of six vineyard pesticides on Typhlodromus pyri Scheuten (Acari: Phytoseiidae), a key predator of the mite Calepitrimerus vitis Nalepa (Acari: Eriophyoidae), in Pacific coastal vineyards. Materials tested were whey powder, 25% boscalid + 13% pyraclostrobin (Pristine), 40% myclobutanil (Rally), micronized sulfur (92% WP), 75% ethylene bisdithiocarbamate (mancozeb; Manzate), and 91.2% paraffinic oil (JMS Stylet), all applied at three concentrations. Pesticide dilutions were directly sprayed onto T. pyri adult females and juveniles, and each treatment was assessed to determine effects on direct mortality and fecundity. Five of the six pesticides tested resulted in < 50% mortality to adult and juvenile T. pyri for all concentrations 7 d after treatment. Paraffinic oil treatments displayed direct mortality > 50% for adult and juvenile assays and resulted in significantly higher mortality. Sublethal effects were more pronounced than acute pesticide toxicity, particularly in juvenile mite bioassays. Significant decreases in fecundity were detected in the sulfur and mancozeb treatments compared with the control in juvenile tests. The relative percentage of fecundity reduction for juvenile mites was highest when applying mancozeb (> 70%), sulfur (> 25%), or myclobutanil (> 20%). Adult mites displayed the greatest reductions in fecundity from applications of paraffinic oil (> 20%) or mancozeb (> 15%) treatments. Boscalid (+ pyraclostrobin) and whey displayed the least effect on fecundity across all bioassays. These results can be used to develop management guidelines in vineyard pest management practices to help conserve and enhance predatory mite populations.

Comparative Evaluation of a Silicone Membrane as an Alternative to Skin for Testing Mosquito Repellents.

PubMed

Agramonte, Natasha M; Gezan, Salvador A; Bernier, Ulrich R

2017-05-01

Repellents prevent mosquito bites and help reduce mosquito-borne disease, a global public health issue. Laboratory-based repellent bioassays predict the ability of compounds to deter mosquito feeding, but the variety of repellent bioassays and statistical analysis methods makes it difficult to compare results across methodologies. The most realistic data are collected when repellents are applied on the skin; however, this method exposes volunteers to chemicals and mosquito bites. Silicone membranes were investigated as an alternative to human skin in assays of repellent efficacy. Results from module system bioassays conducted in vitro with a silicone membrane were compared with in vivo bioassays conducted with N,N-diethyl-3-methylbenzamide (referred to as DEET), 1-piperidinecarboxylic acid 2-(2-hydroxyethyl)-1-methylpropylester (referred to as Picaridin), ethyl 3-[acetyl(butyl)amino]propanoate (referred to as IR3535), and para-menthane-3,8-diol (referred to as PMD) applied directly on the skin of the leg. No significant difference in mosquito feeding was found when comparing skin and volunteer-worn membrane controls using blood; however, feeding was significantly lower in unworn membrane controls using either 10% sucrose or blood, indicating that worn membranes are a possible surrogate for untreated human skin. Pooled data from six volunteers were used to generate dose-response curves of blood-feeding activity. Results from skin-applied repellents were modeled to determine if membranes could provide a predictive correlate for skin. Goodness-of-fit comparisons indicated that the nonlinear dose-response curves for the skin and membrane differed significantly for DEET and Picaridin, but did not differ significantly for IR3535 and PMD. With knowledge of the dose-response relationships and further modifications to this system, the membrane-based tests could be used for standardized repellent testing with infected vectors. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

Deltamethrin resistance in the sea louse Caligus rogercresseyi (Boxhall and Bravo) in Chile: bioassay results and usage data for antiparasitic agents with references to Norwegian conditions.

PubMed

Helgesen, K O; Bravo, S; Sevatdal, S; Mendoza, J; Horsberg, T E

2014-10-01

The sea louse Caligus rogercresseyi is a major threat to Chilean salmonid farming. Pyrethroids have been used for anticaligus treatments since 2007, but have shown reduced effect, most likely due to resistance development. Pyrethroid resistance is also a known problem in Lepeophtheirus salmonis in the Northern Hemisphere. This study describes the development of deltamethrin resistance in C. rogercresseyi based on bioassays and usage data for pyrethroids in Chilean aquaculture. These results were compared to bioassays from L. salmonis from Norway and to Norwegian usage data. Available deltamethrin bioassay results from 2007 and 2008, as well as bioassays from Norway, were collected and remodelled. Bioassays were performed on field-collected sea lice in region X in Chile in 2012 and 2013. Bioassays from 2007 were performed prior to the introduction of pyrethroids to the Chilean market. Both the results from 2008 and 2012 showed an increased resistance. Increased pyrethroid resistance was also indicated by the increased use of pyrethroids in Chilean aquaculture compared with the production of salmonids. A similar trend was seen in the Norwegian usage data. The bioassay results from Chile from 2012 and 2013 also indicated a difference in the susceptibility to deltamethrin between male and female caligus. © 2014 John Wiley & Sons Ltd.

Episodic acidification of small streams in the northeastern united states: Fish mortality in field bioassays

USGS Publications Warehouse

Van Sickle, J.; Baker, J.P.; Simonin, H.A.; Baldigo, Barry P.; Kretser, W.A.; Sharpe, W.E.

1996-01-01

In situ bioassays were performed as part of the Episodic Response Project, to evaluate the effects of episodic stream acidification on mortality of brook trout (Salvelinus fontinalis) and forage fish species. We report the results of 122 bioassays in 13 streams of the three study regions: the Adirondack mountains of New York, the Catskill mountains of New York, and the Northern Appalachian Plateau of Pennsylvania. Bioassays during acidic episodes had significantly higher mortality than did bioassays conducted under nonacidic conditions, but there was little difference in mortality rates in bioassays experiencing acidic episodes and those experiencing acidic conditions throughout the test period. Multiple logistic regression models were used to relate bioassay mortality rates to summary statistics of time-varying stream chemistry (inorganic monomeric aluminum, calcium, pH, and dissolved organic carbon) estimated for the 20-d bioassay periods. The large suite of candidate regressors also included biological, regional, and seasonal factors, as well as several statistics summarizing various features of aluminum exposure duration and magnitude. Regressor variable selection and model assessment were complicated by multicol-linearity and overdispersion. For the target fish species, brook trout, bioassay mortality was most closely related to time-weighted median inorganic aluminum. Median Ca and minimum pH offered additional explanatory power, as did stream-specific aluminum responses. Due to high multicollinearity, the relative importance of different aluminum exposure duration and magnitude variables was difficult to assess, but these variables taken together added no significant explanatory power to models already containing median aluminum. Between 59 and 79% of the variation in brook trout mortality was explained by models employing between one and five regressors. Simpler models were developed for smaller sets of bioassays that tested slimy and mottled sculpin (Cottus cognatus and C. bairdi) as well as blacknose dace (Rhinichthys atratulus). For these forage species a single inorganic aluminum exposure variable successfully accounted for 86-98% of the observed mortality. Even though field bioassays showed evidence of multiple toxicity factors, model results suggest that adequate mortality predictions can be obtained from a single index of inorganic Al concentrations during exposure periods.

Mixture effects in samples of multiple contaminants - An inter-laboratory study with manifold bioassays.

PubMed

Altenburger, Rolf; Scholze, Martin; Busch, Wibke; Escher, Beate I; Jakobs, Gianina; Krauss, Martin; Krüger, Janet; Neale, Peta A; Ait-Aissa, Selim; Almeida, Ana Catarina; Seiler, Thomas-Benjamin; Brion, François; Hilscherová, Klára; Hollert, Henner; Novák, Jiří; Schlichting, Rita; Serra, Hélène; Shao, Ying; Tindall, Andrew; Tolefsen, Knut-Erik; Umbuzeiro, Gisela; Williams, Tim D; Kortenkamp, Andreas

2018-05-01

Chemicals in the environment occur in mixtures rather than as individual entities. Environmental quality monitoring thus faces the challenge to comprehensively assess a multitude of contaminants and potential adverse effects. Effect-based methods have been suggested as complements to chemical analytical characterisation of complex pollution patterns. The regularly observed discrepancy between chemical and biological assessments of adverse effects due to contaminants in the field may be either due to unidentified contaminants or result from interactions of compounds in mixtures. Here, we present an interlaboratory study where individual compounds and their mixtures were investigated by extensive concentration-effect analysis using 19 different bioassays. The assay panel consisted of 5 whole organism assays measuring apical effects and 14 cell- and organism-based bioassays with more specific effect observations. Twelve organic water pollutants of diverse structure and unique known modes of action were studied individually and as mixtures mirroring exposure scenarios in freshwaters. We compared the observed mixture effects against component-based mixture effect predictions derived from additivity expectations (assumption of non-interaction). Most of the assays detected the mixture response of the active components as predicted even against a background of other inactive contaminants. When none of the mixture components showed any activity by themselves then the mixture also was without effects. The mixture effects observed using apical endpoints fell in the middle of a prediction window defined by the additivity predictions for concentration addition and independent action, reflecting well the diversity of the anticipated modes of action. In one case, an unexpectedly reduced solubility of one of the mixture components led to mixture responses that fell short of the predictions of both additivity mixture models. The majority of the specific cell- and organism-based endpoints produced mixture responses in agreement with the additivity expectation of concentration addition. Exceptionally, expected (additive) mixture response did not occur due to masking effects such as general toxicity from other compounds. Generally, deviations from an additivity expectation could be explained due to experimental factors, specific limitations of the effect endpoint or masking side effects such as cytotoxicity in in vitro assays. The majority of bioassays were able to quantitatively detect the predicted non-interactive, additive combined effect of the specifically bioactive compounds against a background of complex mixture of other chemicals in the sample. This supports the use of a combination of chemical and bioanalytical monitoring tools for the identification of chemicals that drive a specific mixture effect. Furthermore, we demonstrated that a panel of bioassays can provide a diverse profile of effect responses to a complex contaminated sample. This could be extended towards representing mixture adverse outcome pathways. Our findings support the ongoing development of bioanalytical tools for (i) compiling comprehensive effect-based batteries for water quality assessment, (ii) designing tailored surveillance methods to safeguard specific water uses, and (iii) devising strategies for effect-based diagnosis of complex contamination. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Risk assessment of the National Institute of Standards and Technology petroleum crude oil standard water accommodated fraction: further application of a copepod-based, full life-cycle bioassay.

PubMed

Bejarano, Adriana C; Chandler, G Thomas; He, Lijian; Cary, Tawnya L; Ferry, John L

2006-07-01

The U.S. National Institute of Standards and Technology (NIST) petroleum crude oil was used to generate NIST water-accommodated hydrocarbon fractions (WAFs) for standardized assessment of crude oil effects on the copepod Amphiascus tenuiremis. Effects were assessed using a 96-well microplate, full life-cycle test. Briefly, nauplii (age, 24 h) were reared individually to adults (n > or =120 nauplii/treatment) in microplate wells containing 200 microl of treatment solution (seawater control [0%] or 10, 30, 50, or 100% NIST-WAF). Nauplii were monitored through development to adulthood, and mature virgin male:female pairs mated in wells containing original treatments (<30 d). A second bioassay using 0, 10, 30, and 50% WAFs (n > or =60 nauplii/treatment) was conducted to assess the effects of ultraviolet (UV) light on naupliar endpoints (<16 d). In the first experiment, nauplius-to-copepodite survival in exposures to 100% WAF was 27% +/- 6% lower than in controls (92% +/- 1%), but copepodite-to-adult survival was greater than 90% across all treatments. Analysis of development curves showed that nauplii in the 10% WAF developed into copepodites 25% faster, whereas nauplii in the 50 and 100% WAFs developed 17% slower, than controls. Copepodite development into male and female copepods was significantly delayed (2 and 4 d, respectively) in the 100% WAF compared to controls. Although none of the WAF exposures had significant effects on fertilization success or total viable production (p > 0.05), embryo hatching in the 100% WAF was significantly less (70.0% +/- 21.2%) than that in controls (87.0% +/- 19.4%). Results from the UV bioassay showed that relatively short exposures (<14 d) to 30 and 50% WAFs in the presence of UV light caused negative effects on copepod survival and development. Naupliar-stage survival and developmental endpoints were the most sensitive indicators of exposure to the NIST crude oil WAF

Nutritional value of enzyme- or sodium hydroxide-treated feathers from dead hens.

PubMed

Kim, W K; Patterson, P H

2000-04-01

Two feather digestion processes to remove the feathers from the carcasses of dead hens were evaluated for their impact on the nutritional quality of the resulting feather meal. There were three treatments: control (untreated feathers), a feather-digesting enzyme, and NaOH treatment. Both enzyme- and NaOH-treated feathers were easily separated from the hen carcasses. The CP level of enzyme-treated feathers after autoclaving (49.90%) was significantly less than the control and NaOH-treated feathers (94.48 and 87.31%, respectively) because of elevated ether extract levels resulting from skin and abdominal fat release during the 12-h enzyme incubation. Before autoclaving, pepsin digestibilities of enzyme- and NaOH-treated feathers were significantly higher than the control. However, after autoclaving, no significant difference was found in pepsin digestibility between the control and enzyme treatments or control and NaOH treatments. The typical limiting amino acids, methionine, lysine, and histidine, in feathers were present at greater levels in the resulting enzyme-feather meal (E-FM) compared with the NaOH-feather meal (N-FM) or control-feather meal (C-FM) on a percentage of CP basis. Cystine levels, however, were significantly lower in the E-FM and N-FM compared with that of the C-FM. In chick bioassays, no significant differences were found in protein efficiency ratio (PER) and net protein ratio (NPR) among C-FM, E-FM, and N-FM. The AMEn of E-FM (4.52 kcal/g) was significantly higher than the C-FM (3.58) or N-FM (2.79). These findings indicated that although enzyme treatment could improve the nutritional quality of feathers from dead hens, NaOH treatment was a more rapid means of separating feathers from the carcass.

Towards improved biomonitoring tools for an intensified sustainable multi-use environment.

PubMed

van der Meer, Jan Roelof

2016-09-01

The increasing use of our environment for multiple contrasting activities (e.g. fisheries, tourism) will have to be accompanied by improved monitoring of environmental quality, to avoid transboundary conflicts and ensure long-term sustainable intensified usage. Biomonitoring approaches are appropriate for this, since they can integrate biological effects of environmental exposure rather than measure individual compound concentrations. Recent advances in biomonitoring concepts and tools focus on single-cell assays and purified biological components that can be miniaturized and integrated in automated systems. Despite these advances, we are still very far from being able to deploy bioassays routinely in environmental monitoring, mostly because of lack of experience in interpreting responses and insufficient robustness of the biosensors for their environmental application. Further future challenges include broadening the spectrum of detectable compounds by biosensors, accelerate response times and combining sample pretreatment strategies with bioassays. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Nestmate recognition in social wasps: manipulation of hydrocarbon profiles induces aggression in the European hornet

NASA Astrophysics Data System (ADS)

Ruther, Joachim; Sieben, Stefan; Schricker, Burkhard

2002-03-01

The influence of individual cuticular hydrocarbons on nestmate recognition in the European hornet, Vespa crabro L., was investigated. We observed the behavioural response of workers towards differently treated dead conspecifics in a bioassay. Dummies were extracted with dichloromethane and extracts were spiked with microgram amounts of synthetic hydrocarbons naturally occurring on the cuticle of V. crabro. These modified extracts were reapplied to extracted workers that were subsequently tested in the bioassay. Non-spiked nestmate dummies (negative control) and untreated non-nestmate dummies (positive control) were tested in control experiments. The addition of only heneicosane or a mixture of heneicosane, tricosane, and ( Z)-9-tricosene to the extracts led to a significant increase of agonistic behaviour in workers leaving the nest for foraging flights. Returning workers reacted much less aggressively than those leaving. This is one of the first behavioural proofs that manipulation of cuticular hydrocarbon profiles can be perceived by a social insect species. The results support the hypothesis that colony-specific cuticular hydrocarbon profiles are involved in the phenomenon of nestmate recognition among social insects.

Anopheles sinensis mosquito insecticide resistance: comparison of three mosquito sample collection and preparation methods and mosquito age in resistance measurements.

PubMed

Xu, Tielong; Zhong, Daibin; Tang, Linhua; Chang, Xuelian; Fu, Fengyang; Yan, Guiyun; Zheng, Bin

2014-01-28

Insecticide resistance monitoring in malaria mosquitoes is essential for guiding the rational use of insecticides in vector control programs. Resistance bioassay is the first step for insecticide monitoring and it lays an important foundation for molecular examination of resistance mechanisms. In the literature, various mosquito sample collection and preparation methods have been used, but how mosquito sample collection and preparation methods affect insecticide susceptibility bioassay results is largely unknown. The objectives of this study were to determine whether mosquito sample collection and preparation methods affected bioassay results, which may cause incorrect classification of mosquito resistance status. The study was conducted in Anopheles sinensis mosquitoes in two study sites in central China. Three mosquito sample collection and preparation methods were compared for insecticide susceptibility, kdr frequencies and metabolic enzyme activities: 1) adult mosquitoes collected from the field; 2) F1 adults from field collected, blood-fed mosquitoes; and 3) adult mosquitoes reared from field collected larvae. Mosquito sample collection and preparation methods significantly affected mortality rates in the standard WHO tube resistance bioassay. Mortality rate of field-collected female adults was 10-15% higher than in mosquitoes reared from field-collected larvae and F1 adults from field collected blood-fed females. This pattern was consistent in mosquitoes from the two study sites. High kdr mutation frequency (85-95%) with L1014F allele as the predominant mutation was found in our study populations. Field-collected female adults consistently exhibited the highest monooxygenase and GST activities. The higher mortality rate observed in the field-collected female mosquitoes may have been caused by a mixture of mosquitoes of different ages, as older mosquitoes were more susceptible to deltamethrin than younger mosquitoes. Female adults reared from field-collected larvae in resistance bioassays are recommended to minimize the effect of confounding factors such as mosquito age and blood feeding status so that more reliable and reproducible mortality may be obtained.

Development of a chick bioassay for determination of infectivity of viral pathogens in poultry litter.

PubMed

Islam, A F M F; Walkden-Brown, S W; Groves, P J; Wells, B

2013-01-01

To develop a chicken bioassay to detect infective viral pathogens in poultry litter and to determine the effects of type of chicken and age of exposure, as well as the effect of simulated litter transportation, on the level of viral infectivity detected. A 5 × 2 × 2 factorial design, plus negative controls. Five chicken litters, including two with deliberate contamination (one transported and one not), two chicken types (specific-pathogen-free (SPF) Leghorns and Cobb broilers) and two ages at initial exposure (days 1 and 8). Two replicates of each treatment combination. The 10 chickens in each of 22 isolators were either exposed (20 isolators) or not (2 isolators) to 8 L of previously used or deliberately contaminated poultry litter in two deep scratch trays. At day 35 post-exposure, sera were assayed for antibodies against chicken anaemia virus (CAV), infectious bronchitis virus (IBV), infectious bursal disease virus (IBDV), Newcastle disease virus (NDV) and fowl adenovirus (FAV). Spleen samples were tested for Marek's disease virus (MDV) using real-time polymerase chain reaction. The bioassay detected CAV, IBDV and FAV, but not NDV, IBV or MDV, in chickens exposed to infected litters. Infection in SPF chickens was detected with greater sensitivity than in the broiler chickens. Sensitivity increased with age at exposure in broiler but not SPF chickens. Simulated transportation for 24 h had little effect on pathogen detection. A bioassay based on the exposure of day-old SPF chickens to poultry litter and measurement of seroconversion at day 35 post-exposure is a useful semi-quantitative assay for viral infectivity in poultry litter, with overnight transportation of litter having little effect on the level of viral infectivity detected. This bioassay has applications in research on litter treatment protocols. © 2013 The Authors. Australian Veterinary Journal © 2013 Australian Veterinary Association.

Bioassays to quantify impacts of CECs in Wastewater, Surface Water, and Drinking Water : Pathway-Based In Vitro Screening

EPA Science Inventory

I will be giving 2 invited presentations during a 2 day meeting at Marquette University. the presentations will focus on our bioassay work on wastewater, surface water, and drinking water and bioassay work on CAFOs.

Estimation of median lethal concentration of three isolates of Beauveria bassiana for control of Megacopta cribraria (Heteroptera: Plataspidae) bioassayed on solid Lugys Spp. Diet²

USDA-ARS?s Scientific Manuscript database

The entomopathogenic fungus Beauveria bassiana is a potential candidate for biological control of a variety of pests. The objectives of this study were isolate and identify the fungus from Kudzu bugs and determine its infectivity comparing with two highly pathogenic isolates including the Mississipp...

NTP Carcinogenesis Bioassay of Diallyl Phthalate (CAS No. 131-17-9) in B6C3F1 Mice (Gavage Study).

PubMed

1983-04-01

Diallyl phthalate is a widely used crosslinking agent for unsaturated polyesters. Diallyl phthalate or diallyl phthalate polyester blends are used primarily as plasticizers and carriers for adding catalysts and pigments to polyesters and in molding, electrical parts, laminating compounds, and impregnation of metal castings. Rubber compounds, epoxy formulations, and polyurethane foams may also contain diallyl phthalate. Annual production of diallyl phthalate in the United States exceeds 5,000 pounds; precise figures are not available. A NTP Carcinogenesis bioassay of diallyl phthalate (99% pure) was conducted by administering 0 (vehicle control), 150, or 300 mg/kg diallyl phthalate in corn oil by gavage, 5 days per week for 103 weeks, to groups of 50 male and 50 female B6C3F1 mice. Survival rates and mean body weights of dosed mice were not different from those of the controls, and pathological lesions unrelated to proliferative changes were not observed. Therefore, a maximally tolerated dose for the purposes of carcinogenicity testing may not have been achieved. The incidences of lymphoma and either lymphoma or leukemia in dosed male mice were no significantly greater than those in the controls according to pairwise comparisons (P=0.051 to P=0.096), but the trend tests were statistically significant by either life table or incidental tumor analysis (P=0.031 to P=0.045). The incidence of lymphomas in the high-dose male mice was 12/50 (24%) in comparison with 6/50 (12%) in the controls. Recent historical incidences at the performing laboratory and in the NTP Bioassay Program were 18/120 (15%) and 71/661 (11%), respectively. Since the incidence of high-dose male mice with leukemia was not significantly greater than that of concurrent or historical controls at the performing laboratory by pairwise comparisons, this marginal increase was considered only to be equivocally related to diallyl phthalate administration. Increased incidences of squamous cell papillomas, hyperplasia, and inflammatory lesions of the forestomach were observed in diallyl phthalate-dosed mice of both sexes in a dose-related manner. Papillomas of the forestomach were observed in 0%, 2%, and 4% of the control, low-dose, and high-dose mice of both sexes. The recent historical incidence of this tumor in gavage control mice from both the performing laboratory and other laboratories within the Bioassay Program was less than 1%. Forestomach hyperplasia was diagnosed in 0%, 15%, and 18%, and in 8%, 2%, and 29% of the control, low-dose, and high-dose male and female mice, respectively; chronic inflammation of the forestomach was diagnosed in 0%, 9%, and 16% and in 4%, 2%, and 18% of the control, low-dose, and high-dose male and female mice, respectively. Because of the numerical elevation of the forestomach papillomas in the high-dose mice of both sexes, the concomitant observation of dose related forestomach hyperplasia, and the rarity of this tumor in corn oil (gavage) control B6C3F1 mice, the development of squamous cell papillomas of the forestomach may have been related to diallyl phthalate administration. Under the conditions of this bioassay, the development of chronic inflammation and hyperplasia of the forestomach in both male and female B6C3F1 mice was considered to be related to the administration of diallyl phthalate. The development of squamous cell papillomas of the forestomach may also have been related to chemical administration, but the available data are insufficient to indicate a clear cause and effect relationship. An increase in the incidence of male mice with lymphomas was observed, but this increase was considered only to be equivocally related to diallyl phthalate administration. The results of this bioassay, therefore, do not indicate that diallyl phthalate is carcinogenic in B6C3F1 mice, although a maximum tolerated dose may not have been achieved. A carcinogenicity study by the National Toxicology Program of diallyl phthalate in male and female Fisher 344/N rats, employing daily gavage doses of 0 (vehicle control), 50, or 100 mg/kg boicology Program of diallyl phthalate in male and female Fisher 344/N rats, employing daily gavage doses of 0 (vehicle control), 50, or 100 mg/kg body weight is currently being evaluated. Levels of Evidence of Carcinogenicity: Male Mice: Equivocal Female Mice: Equivocal

Impact of Spodoptera frugiperda neonate pretreatment conditions on Vip3Aa19 insecticidal protein activity and laboratory bioassay variation.

PubMed

Da Silva, Karen F; Spencer, Terence A; Camargo Gil, Carolina; Siegfried, Blair D; Walters, Frederick S

2016-04-01

Variation in response to insecticidal proteins is common upon repetition of insect bioassays. Understanding this variation is a prerequisite to detecting biologically important differences. We tracked neonate Spodoptera frugiperda (J.E. Smith) susceptibility to Vip3Aa19 over 17 generations using standardized bioassay methods. Five larval pretreatment conditions and one bioassay condition were tested to determine whether susceptibility was affected. These included: storage time; prefeeding; storage at reduced temperature; storage at reduced humidity; colony introgression of field-collected individuals. Extremes of photoperiod during the bioassay itself were also examined. LC50 values for two strains of S. frugiperda varied 6.6-fold or 8.8-fold over 17 generations. Storage time and humidity had no impact on Vip3Aa19 susceptibility, whereas prefeeding significantly reduced subsequent mortality (by 27%). Storage at reduced temperature increased mortality for one colony (from 45.6 to 73.0%) but not for the other. Introgression of field-collected individuals affected susceptibility at the first generation but not for subsequent generations. A 24 h bioassay photophase significantly reduced susceptibility (by 26%) for both colonies. Certain pretreatment and bioassay conditions were identified that can affect S. frugiperda Vip3Aa19 susceptibility, but innate larval heterogeneity was also present. Our observations should help to increase the consistency of insecticidal protein bioassay results. © 2015 Syngenta Crop Protection, LLC. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sensitivity of toad tadpoles, Bufo melanostictus (Schneider), to heavy metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khangarot, B.S.; Ray, P.K.

1987-03-01

Amphibian larval stages have several qualities which make them as a useful indicator of harmful levels of pollutants in bioassay tests. Amphibian tadpoles show a variety of sublethal responses such as changes in growth, development rates, pigmentation and expression of morphological deformities in a lesser time of exposure to the environmental pollutants. The objective of the work reported in this paper was to determine the acute toxicity of cadmium, copper, chromium, mercury, nickel, silver and zinc to the tadpoles of toad Bufo melanostictus (Schneider), which is commonly available and breed in aquatic habitats exhibiting a wide range of temperature andmore » varying water quality.« less

Developing a quick and inexpensive in vitro (non-animal) bioassay for mascara irritation.

PubMed

Thomason, H; Montagnes, D J S

2014-04-01

Mascara is a mild irritant that causes a range of medical problems. Animal models to predict ocular irritation have, however, been questioned at a number of levels, and there is a continued need to develop in vitro testing methods. We assess changes in an easily quantifiable attribute, ciliated protozoan growth rate, as a sensitive, sublethal measure. Specifically, we test six, randomly chosen, commercial mascara products against a control (as treatments) and reveal through ANOVA (n = 6, α = 0.05) significant differences in the specific growth rate to treatments (for both protozoa). We provide evidence that two easily cultured protozoa (Paramecium caudatum, Blepharisma japonicum) should be considered as models to assess ocular irritancy (and possibly cosmetics in general) and establish the groundwork for such studies to be applied at a more commercial level. We do this by developing a bioassay for mascara toxicity and indicate the low cost (after equipment is purchased, on the order of $100s) and the ease of performing such tests (able to be conducted by undergraduate students), as a consideration for their future commercial application. We first examined dose dependence of responses, revealing that there was a need to conduct preliminary work to determine appropriate levels for sublethal responses. We then show that some products resulted in mortality at high concentrations, others decreased growth rate by >50% (compared with the control), whereas others had no significant effect, compared with the control. We have provided a novel, quick and inexpensive means to assess mascara; the next step is to validate these ciliate bioassays by comparison with animal testing and epidemiological studies, which is beyond the scope of this fundamental 'proof-of-concept' study. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Role of neonicotinyl insecticides in Washington apple integrated pest management. Part I. Control of lepidopteran pests

PubMed Central

Brunner, J. F.; Beers, E. H.; Dunley, J. E.; Doerr, M.; Granger, K.

2005-01-01

Three neonicotinyl insecticides, acetamiprid, thiacloprid and clothianidin, were evaluated for their impact on four species of lepidopteran pests of apple in Washington, the codling moth, Cydia pomonella (L.), the Pandemis leafroller, Pandemis pyrusana Kearfott, and the obliquebanded leafroller, Choristoneura rosaceana (Harris), and Lacanobia subjuncta (Grote & Robinson). None of the neonicotinyl insecticides demonstrated sufficient activity against P. pyrusana, C. rosaceana, or L. subjuncta to warrant field trials. Conversely, all had some activity against one or more stages of C. pomonella. Acetamiprid was highly toxic to larvae in laboratory bioassays, and had relatively long activity of field-aged residues (21 days). It also showed some toxicity to C. pomonella eggs (via topical exposure) and adults. Acetamiprid provided the highest level of fruit protection from C. pomonella attack in field trials conducted over five years in experimental orchards with extremely high codling moth pressure. Thiacloprid performed similarly in bioassays, but fruit protection in field trials was slightly lower than acetamiprid. Clothianidin showed moderate to high toxicity in bioassays, depending on the C. pomonella stage tested, but poor fruit protection from attack in field trials. None of the neonicotinyl insecticides were as toxic to larvae or effective in protecting fruit as the current standard organophosphate insecticide used for C. pomonella control, azinphosmethyl. However, both acetamiprid and thiacloprid should provide acceptable levels of C. pomonella control in commercial orchards where densities are much lower than in the experimental orchards used for our trials. The advantages and disadvantages of the neonicotinyl insecticides as replacements for the organophosphate insecticides and their role in a pest management system for Washington apple orchards are discussed. Abbreviation: MFR Maximum field rate PMID:16341246

Compatibility of the Parasitoid Wasp Spalangia endius (Hymenoptera: Pteromalidae) and Insecticides against Musca domestica (Diptera: Muscidae) as Evaluated by a New Index.

PubMed

Burgess, Edwin R; King, B H

2015-06-01

Various insecticides for the control of the house fly Musca domestica L. were tested for compatibility with a biological control agent, the pupal parasitoid Spalangia endius Walker. Bioassays used the mode in which each organism was expected to be harmed by the insecticides, a surface contact bioassay for S. endius and a feeding bioassay for M. domestica. A Pesticide Compatibility Index (PCI) was created that allows comparison of LC50 values when the mode of exposure to a pesticide differs. First LC50 values were converted into units of prescribed dosages (LPR=LC50-to-prescribed dosage ratio). This study used dosages from labels of granular baits. PCI is the ratio of LPRbiological control agent to LPRpest. For these PCI values, order of compatibility with S. endius was spinosad>thiamethoxam>inotefuran>methomyl>imidacloprid. That spinosad was better than imidacloprid or methomyl, both for parasitoid survival and for killing flies, is consistent with conclusions from the LC50 values. Permethrin and nitenpyram were also tested, but their PCIs were not calculated. Permethrin is prescribed as a contact insecticide against flies rather than being consumed as a bait, and nitenpyram has not been formulated as a fly insecticide. Compared with the other insecticides in terms of LC50 values, permethrin was moderately toxic to S. endius but one of the most toxic for M. domestica, whereas nitenpyram was least toxic for both S. endius and the flies. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Toxicity of waters from the Rochester Embayment Area of Concern to the plankton species Pseudokirchneriella subcapitata and Ceriodaphnia dubia

USGS Publications Warehouse

Baldigo, Barry P.; Duffy, Brian T.; Smith, Alexander J.; George, Scott D.

2016-01-01

The lower Genesee River and Rochester Embayment of Lake Ontario are a designated Area of Concern (AOC) under the binational Great Lakes Water Quality Agreement. The “degradation of phytoplankton and zooplankton populations” or plankton Beneficial Use Impairment (BUI) was classified as unknown and in need of further assessment in this AOC because water quality data suggested plankton communities could be effected and community data were either unavailable or indicated impacts. The plankton BUI may now be obsolete because local contaminant sources have been largely eliminated. The present study was conducted between July 2013 and August 2014 to assess the BUI-removal criteria: “AOC plankton bioassays confirm that toxicity in ambient waters (i.e., no growth inhibition) is not significantly higher than comparable non-AOC controls”. Acute and chronic toxicity of waters from 13 sites were quantified seasonally using standardized bioassays with the green alga Pseudokirchneriella subcapitata and water flea Ceriodaphnia dubia to test the hypothesis that toxicity of waters from AOC sites was not higher than that of waters from comparable non-AOC reference sites. Survival and reproduction of C. dubia did not differ significantly between site types, systems, or months. The growth of P. subcapitata did not differ between site types, but differed among systems and months. All results indicate that waters from AOC sites were no more toxic to both plankton species than waters from reference sites. Assuming test species represent natural plankton assemblages, water quality should not negatively affect survival and growth of resident plankton populations in the Rochester Embayment AOC.

Influence of in-stream diel concentration cycles of dissolved trace metals on acute toxicity to one-year-old cutthroat trout (Oncorhynchus clarki lewisi)

USGS Publications Warehouse

Nimick, D.A.; Harper, D.D.; Farag, A.M.; Cleasby, T.E.; MacConnell, Elizabeth; Skaar, D.

2007-01-01

Extrapolating results of laboratory bioassays to streams is difficult, because conditions such as temperature and dissolved metal concentrations can change substantially on diel time scales. Field bioassays conducted for 96 h in two mining-affected streams compared the survival of hatchery-raised, metal-nai??ve westslope cutthroat trout (Oncorhynchus clarki lewisi) exposed to dissolved (0.1-??m filtration) metal concentrations that either exhibited the diel variation observed in streams or were controlled at a constant value. Cadmium and Zn concentrations in these streams increased each night by as much as 61 and 125%, respectively, and decreased a corresponding amount the next day, whereas Cu did not display a diel concentration cycle. In High Ore Creek (40 km south of Helena, MT, USA), survival (33%) after exposure to natural diel-fluctuating Zn concentrations (range, 214-634 ??g/L; mean, 428 ??g/L) was significantly (p = 0.008) higher than survival (14%) after exposure to a controlled, constant Zn concentration (422 ??g/L). Similarly, in Dry Fork Belt Creek (70 km southeast of Great Falls, MT, USA), survival (75%) after exposure to diel-fluctuating Zn concentrations (range, 266-522 ??g/L; mean, 399 ??g/L) was significantly (p = 0.022) higher than survival (50%) in the constant-concentration treatment (392 ??g/L). Survival likely was greater in these diel treatments, both because the periods of lower metal concentrations provided some relief for the fish and because toxicity during periods of higher metal concentrations was lessened by the simultaneous occurrence each night of lower water temperatures, which reduce the rate of metal uptake. Based on the present study, current water-quality criteria appear to be protective for streams with diel concentration cycles of Zn (and, perhaps, Cd) for the hydrologie conditions tested. ?? 2007 SETAC.

Evaluation of Reduced Sediment Volume Procedures for Acute Toxicity Tests Using the Estuarine Amphipod Leptocheirus plumulosus

EPA Science Inventory

The volume of sediment required to perform a sediment toxicity bioassay is a major driver of the overall cost associated with that bioassay. Sediment volume affects bioassay cost due to sediment collection, transportation, storage, and disposal costs as well as labor costs assoc...

Bioassay criteria for environmental restoration workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, E.H.; Bihl, D.E.

1993-01-01

Environmental restoration (ER) work at the U. S. Department of Energy Hanford Site posed questions concerning when to perform bioassay monitoring of workers for potential intakes of radioactivity. Application of criteria originally developed for use inside radionuclide processing facilities to ER work resulted in overly restrictive bioassay requirements. ER work typically involves site characterization or, excavating large quantities of potentially contaminated soil, rather than working with concentrated quantities of radioactivity as in a processing facility. An improved approach, tailored to ER work, provided soil contamination concentrations above which worker bioassay would be required. Soil concentrations were derived assuming acute ormore » chronic intakes of 2% of an Annual Limit on Intake (ALI), or a potential committed effective dose equivalent of 100 mrem, and conservative dust loading of air from the work. When planning ER work, the anticipated soil concentration and corresponding need for bioassay could be estimated from work-site historical records. Once site work commenced, soil sampling and work-place surveys could be used to determine bioassay needs. This approach substantially reduced the required number of bioassay samples with corresponding reductions in analytical costs, schedules, and more flexible work-force management. (Work supported by the US Department of Energy under contract DOE-AC06-76RLO 1830.)« less

Reverse chemical ecology approach for the identification of a mosquito oviposition attractant

USDA-ARS?s Scientific Manuscript database

Pheromones and other semiochemicals play a crucial role in today’s integrated pest and vector management strategies for controlling populations of insects causing loses to agriculture and vectoring diseases to humans. These semiochemicals are typically discovered by bioassay-guided approaches. Here,...

Dutch Elm Disease and Methoxychlor

Treesearch

Jack H. Barger

1976-01-01

American elm trees, Ulmus americana L., in Milwaukee, Wisconsin, were sprayed with methoxychlor by helicopter or mist blower once each year for 3 years to control the smaller European elm bark beetle Scolytus multistriatus (Marsham). Twig crotches were collected from sprayed trees each year for bioassay. Methoxychlor residues...

Isolation of Fungi from Heterodera glycines and in vitro Bioassays for Their Antagonism to Eggs.

PubMed

Meyer, S L; Huettel, R N; Sayre, R M

1990-10-01

Twenty fungi were assayed in vitro for antagonism to eggs of Heterodera glycines. Eight of the fungi were isolated from cysts or eggs of H. glycines during the current study, one was isolated from Panagrellus redivivus, and eleven were obtained from other researchers or collections. The bioassays were conducted on eggs from nematodes that had been grown monoxenically on excised root tips. Phoma chrysanthemicola, one strain of Verticillium chlamydosporium, and one strain of V. lecanii caused a decrease (P < 0.01, P < 0.05, P < 0.05, respectively) in the number of viable eggs, although no hyphae were observed colonizing live eggs. Trichoderma polysporum infected live eggs but enhanced (P < 0.05) egg survival. Acremonium bacillisporum, Chaetomium sp., Drechmeria coniospora (two strains), Epicoccum sp., Exophiala jeanselmei, Fusarium sp., Neocosmospora vasinfecta, Scytalidium fulvum, Trichoderma harzianum (two strains), V. chlamydosporium (one strain), V. lecanii (three strains), and an unidentified fungus did not measurably affect egg viability, even though hyphae of five of these fungi were seen in live eggs. The bioassay provides a useful step in the selection of a biological control agent for this major nematode pest.

Active monoterpene ketones isolated from Rosmarinus officinalis with fumigant and contact action against Tyrophagus putrescentiae (Schrank).

PubMed

Jeon, Ju-Hyun; Park, Jun-Hwan; Chung, Namhyun; Lee, Hoi-Seon

2014-08-01

The acaricidal activities of an active material derived from Rosmarinus officinalis oil and its relative monoterpene ketones were determined using fumigant and contact toxicity bioassays against Tyrophagus putrescentiae and were compared with that of a commercial acaricide (benzyl benzoate). The active component of R. officinalis oil, isolated by silica gel column chromatography and high-performance liquid chromatography, was identified as camphor, based on various spectroscopic analyses. In the fumigant toxicity bioassay, camphor (2.25 μg/cm(3)) was 5.58 times more active than benzyl benzoate (12.56 μg/cm(3)) against T. putrescentiae, followed by (+)-camphor (3.89 μg/cm(3)) and (-)-camphor (5.61 μg/cm(3)). In the contact toxicity bioassay, camphor (1.34 μg/cm(2)) was 6.74 times more toxic than benzyl benzoate (9.03 μg/cm(2)) against T. putrescentiae, followed by (+)-camphor (2.23 μg/cm(2)) and (-)-camphor (2.94 μg/cm(2)). These results indicate that camphor and its derivatives are very useful as potential control agents against stored food mites regardless of the application method.

Bioassays for assessing jasmonate-dependent defenses triggered by pathogens, herbivorous insects, or beneficial rhizobacteria.

PubMed

Van Wees, Saskia C M; Van Pelt, Johan A; Bakker, Peter A H M; Pieterse, Corné M J

2013-01-01

Jasmonates, together with other plant hormones, are important orchestrators of the plant immune system. The different hormone-controlled signaling pathways cross-communicate in an antagonistic or a synergistic manner, providing the plant with a powerful capacity to finely regulate its immune response. Jasmonic acid (JA) signaling is required for plant resistance to harmful organisms, such as necrotrophic pathogens and herbivorous insects. Furthermore, JA signaling is essential in interactions of plants with beneficial microbes that induce systemic resistance to pathogens and insects. The role of JA signaling components in plant immunity can be studied by performing bioassays with different interacting organisms. Determination of the level of resistance and the induction of defense responses in plants with altered JA components, through mutation or ectopic expression, will unveil novel mechanisms of JA signaling. We provide detailed protocols of bioassays with the model plant Arabidopsis thaliana challenged with the pathogens Botrytis cinerea and Pseudomonas syringae, the insect herbivore Pieris rapae, and the beneficial microbe Pseudomonas fluorescens. In addition, we describe pharmacological assays to study the modulation of JA-regulated responses by exogenous application of combinations of hormones, because a simultaneous rise in hormone levels occurs during interaction of plants with other organisms.

Insecticidal and repellent activities of insecticide-sucrose solutions to Culex pipiens molestus (Diptera: Culicidae) under laboratory and field conditions.

PubMed

Shin, Ehyun; Park, Chan; Ahn, Young-Joon; Lee, Dong-Kyu; Chang, Kyu-Sik

2011-06-01

Culex pipiens molestus Forskal has been reported as a dominant species in underground structures of urban areas in the Republic of Korea (ROK) during all seasons and becomes bothersome to humans in late autumn and winter. Most Cx. pipiens molestus in septic tanks are controlled in the ROK using larvicides such as Bt and IGR. However, there are a number of problems associated with larvicides, such as high cost and requirement for frequent use. In the present work, a new control method for Cx. pipiens molestus in septic tanks by using mixtures of sucrose solution with insecticides was investigated. The insecticidal and repellent activities of ten insecticides were evaluated for best control of Cx. pipiens molestus in septic tanks. Firstly, differences in susceptibilities to insecticides were evaluated in topical assays by forced direct contact bioassay and in a screened wire cage by free direct contact bioassay. The difference in insecticide susceptibility in the mosquitoes was the result of repellency by the insecticides. In three septic tanks, the density of Culex mosquitoes was sharply reduced by a deltamethrin-sucrose solution kit. The results demonstrated the potential for mosquito control by deltamethrin-sucrose solution, and the study offers basic information related to mosquito control in septic tanks. Copyright © 2011 Society of Chemical Industry.

Genotoxic Potential and Physicochemical Parameters of Sinos River, Southern Brazil

PubMed Central

Scalon, Madalena C. S.; Rechenmacher, Ciliana; Siebel, Anna Maria; Kayser, Michele L.; Rodrigues, Manoela T.; Maluf, Sharbel W.; Rodrigues, Marco Antonio S.

2013-01-01

The present study aimed to evaluate the physicochemical parameters and the genotoxic potential of water samples collected in the upper, middle, and lower courses of the Sinos River, southern Brazil. The comet assay was performed in the peripheral blood of fish Hyphessobrycon luetkenii exposed under laboratory conditions to water samples collected in summer and winter in three sampling sites of Sinos River. Water quality analysis demonstrated values above those described in Brazilian legislation in Parobé and Sapucaia do Sul sites, located in the middle and in the lower courses of the Sinos River, respectively. The Caraá site, located in the upper river reach, presented all the physicochemical parameters in accordance with the allowed limits in both sampling periods. Comet assay in fish revealed genotoxicity in water samples collected in the middle course site in summer and in the three sites in winter when compared to control group. Thus, the physicochemical parameters indicated that the water quality of the upper course complies with the limits set by the national guidelines, and the ecotoxicological assessment, however, indicated the presence of genotoxic agents. The present study highlights the importance of combining water physicochemical analysis and bioassays to river monitoring. PMID:24285934

Structuring a risk-based bioassay program for uranium usage in university laboratories

NASA Astrophysics Data System (ADS)

Dawson, Johnne Talia

Bioassay programs are integral in a radiation safety program. They are used as a method of determining whether individuals working with radioactive material have been exposed and have received a resulting dose. For radionuclides that are not found in nature, determining an exposure is straightforward. However, for a naturally occurring radionuclide like uranium, it is not as straightforward to determine whether a dose is the result of an occupational exposure. The purpose of this project is to address this issue within the University of Nevada, Las Vegas's (UNLV) bioassay program. This project consisted of two components that studied the effectiveness of a bioassay program in determining the dose for an acute inhalation of uranium. The first component of the plan addresses the creation of excretion curves, utilizing MATLAB that would allow UNLV to be able to determine at what time an inhalation dose can be attributed to. The excretion curves were based on the ICRP 30 lung model, as well as the Annual Limit Intake (ALI) values located in the Nuclear Regulatory Commission's 10CFR20 which is based on ICRP 30 (International Commission on Radiological Protection). The excretion curves would allow UNLV to be able to conduct in-house investigations of inhalation doses without solely depending on outside investigations and sources. The second component of the project focused on the creation of a risk based bioassay program to be utilized by UNLV that would take into account bioassay frequency that depended on the individual. Determining the risk based bioassay program required the use of baseline variance in order to minimize the investigation of false positives among those individuals who undergo bioassays for uranium work. The proposed program was compared against an evaluation limit of 10 mrem per quarter, an investigational limit of 125 mrem per quarter, and the federal/state requirement of 1.25 rem per quarter. It was determined that a bioassay program whose bioassay frequency varies per person, depending on the chemical class of material being worked with, in conjunction with continuous air monitoring can sufficiently meet ALARA standards.

Water Quality Criteria for Nitroglycerin.

DTIC Science & Technology

1986-07-01

in Bentley et al.’s (1978) algal bioassay with nitroglycerin, the lactose vehicle at a concentra- tion of 10 mg/L caused a 24 percent increase in cell...numbers of .j. canricornutum. Although lactose had also been used at concentrations of 1 and 100 mg/L, Bentley et al. corrected all cell counts for...this species by 24 percent regardless of the lactose concentration; thus they made no allowance for any lessening of this effect at lower vehicle con

A Bioassay Experiment to Determine Water Quality Impacts Related to Trout Mortality at a Hatchery Downstream of Lake Sidney Lanier, Georgia.

DTIC Science & Technology

1982-03-01

mercial products . v1i - - ~ - - . . . - ~ -- w ~ -~. -4~. ABSTRACT A major trout kill occurred at Buford Trout Hatchery in northern Georgia during its...Hydraulic Design Dean Scott, Construction Technician Eddie Taylor, Construction Technician Document Prod uction Deb Kramer, Document Production Manager...aroused no suspicion of any toxicant from municipal or industrial discharges nor from any non-point source. No abnormal levels of chlorinated hydrocar

Resistance monitoring of Heliothis virescens to pyramided cotton varieties with a hydrateable, artificial cotton leaf bioassay

USDA-ARS?s Scientific Manuscript database

Proof of concept was demonstrated for a practical, off the shelf bioassay to monitor for tobacco budworm resistance to pyramided Bt cotton using plant eluants. The bioassay was based on a previously described feeding disruption test using hydrateable artificial diet containing a blue indicator dye, ...

Validation of a Novel Bioassay for Low-level Perchlorate Determination

DTIC Science & Technology

2014-04-01

was not attractive, since these reduce PMS2 , and it was thought they would interfere with the stoichiometry of NADH and perchlorate in the bioassay...these reduce PMS2 directly, and would interfere with the stoichiometry of NADH and perchlorate in the bioassay. Thus the only approach that could be

Validation of a Novel Bioassay for Low-level Perchlorate Determination

DTIC Science & Technology

2013-05-01

since these reduce PMS2 , and it was thought they would interfere with the stoichiometry of NADH and perchlorate in the bioassay. With regard to the...reduce PMS2 directly, and would interfere with the stoichiometry of NADH and perchlorate in the bioassay. Thus the only approach that could be

Pyrethroid resistance persists after ten years without usage against Aedes aegypti in governmental campaigns: Lessons from São Paulo State, Brazil.

PubMed

Macoris, Maria de Lourdes; Martins, Ademir Jesus; Andrighetti, Maria Teresa Macoris; Lima, José Bento Pereira; Valle, Denise

2018-03-01

Aedes aegypti, vector of dengue, chikungunya and Zika viruses, is found at high densities in tropical urban areas. The dissemination of this vector is partially the consequence of failures in current vector control methods, still mainly relying upon insecticides. In the State of São Paulo (SP), Brazil, public health managers employed pyrethroids against Ae. aegypti adults from 1989 to 2000, when a robust insecticide resistance monitoring system detected resistance to pyrethroids in several Ae. aegypti populations. However, pyrethroids are also the preferred compounds engaged in household applications due to their rapid knockdown effect, lower toxicity to mammals and less irritating smell. We evaluated pyrethroid resistance in Ae. aegypti populations over the course of a decade, from 2004 to 2015, after interruption of pyrethroid public applications in SP. Qualitative bioassays with papers impregnated with a deltamethrin diagnostic dose (DD) performed with insects from seven SP municipalities and evaluated yearly from 2006 to 2014, detected resistance in most of the cases. Quantitative bioassays were also carried out with four populations in 2011, suggesting a positive correlation between resistance level and survivorship in the DD bioassays. Biochemical tests conducted with seven insect populations in 2006 and 2015, detected increasing metabolic alterations of all major classes of detoxifying enzymes, mostly of mixed function oxidases. Genotyping of the voltage-gated sodium channel (AaNaV, the pyrethroid target-site) with a TaqMan real time PCR based technique was performed from 2004 to 2014 in all seven localities. The two kdr mutations, Val1016Ile and Phe1534Cys, known to be spread throughout Brazil, were always present with a severe decrease of the susceptible allele over time. These results are discussed in the context of public and domestic insecticide use, the necessity of implementation of a strong integrated vector control strategy and the conceptual misunderstanding between 'vector control' and 'chemical control of vectors'.

Pyrethroid resistance persists after ten years without usage against Aedes aegypti in governmental campaigns: Lessons from São Paulo State, Brazil

PubMed Central

Andrighetti, Maria Teresa Macoris; Lima, José Bento Pereira; Valle, Denise

2018-01-01

Background Aedes aegypti, vector of dengue, chikungunya and Zika viruses, is found at high densities in tropical urban areas. The dissemination of this vector is partially the consequence of failures in current vector control methods, still mainly relying upon insecticides. In the State of São Paulo (SP), Brazil, public health managers employed pyrethroids against Ae. aegypti adults from 1989 to 2000, when a robust insecticide resistance monitoring system detected resistance to pyrethroids in several Ae. aegypti populations. However, pyrethroids are also the preferred compounds engaged in household applications due to their rapid knockdown effect, lower toxicity to mammals and less irritating smell. Methodology/Principal findings We evaluated pyrethroid resistance in Ae. aegypti populations over the course of a decade, from 2004 to 2015, after interruption of pyrethroid public applications in SP. Qualitative bioassays with papers impregnated with a deltamethrin diagnostic dose (DD) performed with insects from seven SP municipalities and evaluated yearly from 2006 to 2014, detected resistance in most of the cases. Quantitative bioassays were also carried out with four populations in 2011, suggesting a positive correlation between resistance level and survivorship in the DD bioassays. Biochemical tests conducted with seven insect populations in 2006 and 2015, detected increasing metabolic alterations of all major classes of detoxifying enzymes, mostly of mixed function oxidases. Genotyping of the voltage-gated sodium channel (AaNaV, the pyrethroid target-site) with a TaqMan real time PCR based technique was performed from 2004 to 2014 in all seven localities. The two kdr mutations, Val1016Ile and Phe1534Cys, known to be spread throughout Brazil, were always present with a severe decrease of the susceptible allele over time. Conclusions/Significance These results are discussed in the context of public and domestic insecticide use, the necessity of implementation of a strong integrated vector control strategy and the conceptual misunderstanding between 'vector control' and 'chemical control of vectors'. PMID:29601580

Isolation and identification of entomopathogenic nematodes from citrus orchards in South Africa and their biocontrol potential against false codling moth.

PubMed

Malan, Antoinette P; Knoetze, Rinus; Moore, Sean D

2011-10-01

A survey was conducted to determine the diversity and frequency of endemic entomopathogenic nematodes (EPN) in citrus orchards in the Western Cape, Eastern Cape and Mpumalanga provinces of South Africa. The main aim of the survey was to obtain nematodes as biological control agents against false codling moth (FCM), Thaumatotibia leucotreta, a key pest of citrus in South Africa. From a total of 202 samples, 35 (17%) tested positive for the presence of EPN. Of these, four isolates (11%) were found to be steinernematids, while 31 (89%) were heterorhabditids. Sequencing and characterisation of the internal transcribed spacer (ITS) region was used to identify all nematode isolates to species level. Morphometrics, morphology and biology of the infective juvenile (IJ) and the first-generation male were used to support molecular identification and characterisation. The Steinernema spp. identified were Steinernema khoisanae, Steinernema yirgalemense and Steinernema citrae. This is the first report of S. yirgalemense in South Africa, while for S. citrae it is the second new steinernematid to be identified from South Africa. Heterorhabditis species identified include Heterorhabditis bacteriophora, Heterorhabditis zealandica and an unknown species of Heterorhabditis. Laboratory bioassays, using 24-well bioassay disks, have shown isolates of all six species found during the survey, to be highly virulent against the last instar of FCM larvae. S. yirgalemense, at a concentration of 50IJs/FCM larva caused 100% mortality and 74% at a concentration of 200IJs/pupa. Using a sand bioassay, S. yirgalemense gave 93% control of cocooned pupae and emerging moths at a concentration of 20IJs/cm(2). This is the first report on the potential use of EPN to control the soil-borne life stages of FCM, which includes larvae, pupae and emerging moths. It was shown that emerging moths were infected with nematodes, which may aid in control and dispersal. Copyright © 2011 Elsevier Inc. All rights reserved.

PubChem BioAssay: 2017 update

PubMed Central

Wang, Yanli; Bryant, Stephen H.; Cheng, Tiejun; Wang, Jiyao; Gindulyte, Asta; Shoemaker, Benjamin A.; Thiessen, Paul A.; He, Siqian; Zhang, Jian

2017-01-01

PubChem's BioAssay database (https://pubchem.ncbi.nlm.nih.gov) has served as a public repository for small-molecule and RNAi screening data since 2004 providing open access of its data content to the community. PubChem accepts data submission from worldwide researchers at academia, industry and government agencies. PubChem also collaborates with other chemical biology database stakeholders with data exchange. With over a decade's development effort, it becomes an important information resource supporting drug discovery and chemical biology research. To facilitate data discovery, PubChem is integrated with all other databases at NCBI. In this work, we provide an update for the PubChem BioAssay database describing several recent development including added sources of research data, redesigned BioAssay record page, new BioAssay classification browser and new features in the Upload system facilitating data sharing. PMID:27899599

29 CFR 1990.111 - General statement of regulatory policy.

Code of Federal Regulations, 2013 CFR

2013-07-01

... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...

29 CFR 1990.111 - General statement of regulatory policy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...

29 CFR 1990.111 - General statement of regulatory policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...

29 CFR 1990.111 - General statement of regulatory policy.

Code of Federal Regulations, 2014 CFR

2014-07-01

... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...

29 CFR 1990.111 - General statement of regulatory policy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... substances, groups of substances, or combinations or mixtures of substances which may be found in workplaces... classified on the basis of human epidemiological studies and/or experimental carcinogenesis bioassays in... primarily through the use of engineering and work practice controls. (i) Worker exposure to Category II...

Application site and mosquito age influences malathion- and permethrin-induced mortality in Culex quinquefasciatus

USDA-ARS?s Scientific Manuscript database

Concentrations of malathion and permethrin typical in droplets generated from ultra-low volume and low volume applications were evaluated for efficacy against multiple-aged Culex quinquefasciatus Say, using a topical bioassay. Although during mosquito control operations insecticide droplets will imp...

Impact of topical application site efficacy of permethrin and malathion on Culex quinquefasciatus

USDA-ARS?s Scientific Manuscript database

Concentrations of permethrin and malathion found in droplets generated from ultra-low volume and low volume sprays used to control adult mosquito populations were evaluated for efficacy against Culex quinquefasciatus Say using a topical application bioassay. Although insecticide droplets will imping...

A versatile electrowetting-based digital microfluidic platform for quantitative homogeneous and heterogeneous bio-assays

NASA Astrophysics Data System (ADS)

Vergauwe, Nicolas; Witters, Daan; Ceyssens, Frederik; Vermeir, Steven; Verbruggen, Bert; Puers, Robert; Lammertyn, Jeroen

2011-05-01

Electrowetting-on-dielectric (EWOD) lab-on-a-chip systems have already proven their potential within a broad range of bio-assays. Nevertheless, research on the analytical performance of those systems is limited, yet crucial for a further breakthrough in the diagnostic field. Therefore, this paper presents the intrinsic possibilities of an EWOD lab-on-a-chip as a versatile platform for homogeneous and heterogeneous bio-assays with high analytical performance. Both droplet dispensing and splitting cause variations in droplet size, thereby directly influencing the assay's performance. The extent to which they influence the performance is assessed by a theoretical sensitivity analysis, which allows the definition of a basic framework for the reduction of droplet size variability. Taking advantage of the optimized droplet manipulations, both homogeneous and heterogeneous bio-assays are implemented in the EWOD lab-on-a-chip to demonstrate the analytical capabilities and versatility of the device. A fully on-chip enzymatic assay is realized with high analytical performance. It demonstrates the promising capabilities of an EWOD lab-on-a-chip in food-related and medical applications, such as nutritional and blood analyses. Further, a magnetic bio-assay for IgE detection using superparamagnetic nanoparticles is presented whereby the nanoparticles are used as solid carriers during the bio-assay. Crucial elements are the precise manipulation of the superparamagnetic nanoparticles with respect to dispensing and separation. Although the principle of using nano-carriers is demonstrated for protein detection, it can be easily extended to a broader range of bio-related applications like DNA sensing. In heterogeneous bio-assays the chip surface is actively involved during the execution of the bio-assay. Through immobilization of specific biological compounds like DNA, proteins and cells a reactive chip surface is realized, which enhances the bio-assay performance. To demonstrate this potential, on-chip adhesion islands are fabricated to immobilize MCF-7 human breast cancer cells. Viability studies are performed to assess the functionalization efficiency.

Colour-barcoded magnetic microparticles for multiplexed bioassays.

PubMed

Lee, Howon; Kim, Junhoi; Kim, Hyoki; Kim, Jiyun; Kwon, Sunghoon

2010-09-01

Encoded particles have a demonstrated value for multiplexed high-throughput bioassays such as drug discovery and clinical diagnostics. In diverse samples, the ability to use a large number of distinct identification codes on assay particles is important to increase throughput. Proper handling schemes are also needed to readout these codes on free-floating probe microparticles. Here we create vivid, free-floating structural coloured particles with multi-axis rotational control using a colour-tunable magnetic material and a new printing method. Our colour-barcoded magnetic microparticles offer a coding capacity easily into the billions with distinct magnetic handling capabilities including active positioning for code readouts and active stirring for improved reaction kinetics in microscale environments. A DNA hybridization assay is done using the colour-barcoded magnetic microparticles to demonstrate multiplexing capabilities.

In vitro bioassays for detecting dioxin-like activity--application potentials and limits of detection, a review.

PubMed

Eichbaum, Kathrin; Brinkmann, Markus; Buchinger, Sebastian; Reifferscheid, Georg; Hecker, Markus; Giesy, John P; Engwall, Magnus; van Bavel, Bert; Hollert, Henner

2014-07-15

Use of in vitro assays as screening tool to characterize contamination of a variety of environmental matrices has become an increasingly popular and powerful toolbox in the field of environmental toxicology. While bioassays cannot entirely substitute analytical methods such as gas chromatography-mass spectrometry (GC-MS), the increasing improvement of cell lines and standardization of bioassay procedures enhance their utility as bioanalytical pre-screening tests prior to more targeted chemical analytical investigations. Dioxin-receptor-based assays provide a holistic characterization of exposure to dioxin-like compounds (DLCs) by integrating their overall toxic potential, including potentials of unknown DLCs not detectable via e.g. GC-MS. Hence, they provide important additional information with respect to environmental risk assessment of DLCs. This review summarizes different in vitro bioassay applications for detection of DLCs and considers the comparability of bioassay and chemical analytically derived toxicity equivalents (TEQs) of different approaches and various matrices. These range from complex samples such as sediments through single reference to compound mixtures. A summary of bioassay derived detection limits (LODs) showed a number of current bioassays to be equally sensitive as chemical methodologies, but moreover revealed that most of the bioanalytical studies conducted to date did not report their LODs, which represents a limitation with regard to low potency samples. Copyright © 2014 Elsevier B.V. All rights reserved.

COMPARISON OF BIOASSAY AND ENZYME-LINKED IMMUNOSORBENT ASSAY FOR QUANTIFICATION OF 'SPODOPTERA FRUGIPERDA' NUCLEAR POLYHEDROSIS VIRUS IN SOIL

EPA Science Inventory

Standard curves with known amounts of Spodoptera frugiperda nuclear polyhedrosis virus (NPV) in soil were established with a bioassay and with an enzyme-linked immunosorbent assay (ELISA). The bioassay detected as few as 4 x 10 to the 4th power polyhedral inclusion bodies (PIB)/g...

Two case studies of highly insoluble plutonium inhalation with implications for bioassay.

PubMed

Carbaugh, E H; La Bone, T R

2003-01-01

Two well characterised Pu inhalation cases show some remarkable similarities between substantially different types of Pu oxide. The circumstances of exposure, therapy, bioassay data, chemical solubility studies and dosimetry associated with these cases suggest that highly insoluble Pu may be more common than previously thought, and can pose significant challenges to bioassay programmes.

Two Case Studies of Highly Insoluble Plutonium Inhalation with Implications for Bioassay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; La Bone, Thomas R.

2003-01-01

Two well-characterized Pu inhalation cases show some remarkable similarities between substantially different types of Pu oxide. The circumstances of exposure, therapy, bioassay data, chemical solubility studies, and dosimetry associated with these cases suggests taht highly insoluble Pu may be more common than previously thought, and can pose significant challenges to bioassay programs.

Bioassay vs. Air Sampling: Practical Guidance and Experience at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Carlson, Eric W.; Hill, Robin L.

2004-02-08

The Hanford Site has implemented a policy to guide in determining whether air sampling data or special fecal bioassay data are more appropriate for determining doses of record for low-level plutonium exposures. The basis for the policy and four years of experience in comparing DAC-hours exposure with bioassay-based dosimetry is discussed.

UTILITY OF A FULL LIFE-CYCLE COPEPOD BIOASSAY APPROACH FOR ASSESSMENT OF SEDIMENT-ASSOCIATED CONTAMINANT MIXTURES. (R825279)

EPA Science Inventory

Abstract

We compared a 21 day full life-cycle bioassay with an existing 14 day partial life-cycle bioassay for two species of meiobenthic copepods, Microarthridion littorale and Amphiascus tenuiremis. We hypothesized that full life-cycle tests would bette...

Manufacturing history of etanercept (Enbrel®): Consistency of product quality through major process revisions.

PubMed

Hassett, Brian; Singh, Ena; Mahgoub, Ehab; O'Brien, Julie; Vicik, Steven M; Fitzpatrick, Brian

2018-01-01

Etanercept (ETN) (Enbrel®) is a soluble protein that binds to, and specifically inhibits, tumor necrosis factor (TNF), a proinflammatory cytokine. ETN is synthesized in Chinese hamster ovary cells by recombinant DNA technology as a fusion protein, with a fully human TNFRII ectodomain linked to the Fc portion of human IgG1. Successful manufacture of biologics, such as ETN, requires sophisticated process and product understanding, as well as meticulous control of operations to maintain product consistency. The objective of this evaluation was to show that the product profile of ETN drug substance (DS) has been consistent over the course of production. Multiple orthogonal biochemical analyses, which included evaluation of attributes indicative of product purity, potency, and quality, were assessed on >2,000 batches of ETN from three sites of DS manufacture, during the period 1998-2015. Based on the key quality attributes of product purity (assessed by hydrophobic interaction chromatography HPLC), binding activity (to TNF by ELISA), potency (inhibition of TNF-induced apoptosis by cell-based bioassay) and quality (N-linked oligosaccharide map), we show that the integrity of ETN DS has remained consistent over time. This consistency was maintained through three major enhancements to the initial process of manufacturing that were supported by detailed comparability assessments, and approved by the European Medicines Agency. Examination of results for all major quality attributes for ETN DS indicates a highly consistent process for over 18 years and throughout changes to the manufacturing process, without affecting safety and efficacy, as demonstrated across a wide range of clinical trials of ETN in multiple inflammatory diseases.

The limits of two-year bioassay exposure regimens for identifying chemical carcinogens.

PubMed

Huff, James; Jacobson, Michael F; Davis, Devra Lee

2008-11-01

Chemical carcinogenesis bioassays in animals have long been recognized and accepted as valid predictors of potential cancer hazards to humans. Most rodent bioassays begin several weeks after birth and expose animals to chemicals or other substances, including workplace and environmental pollutants, for 2 years. New findings indicate the need to extend the timing and duration of exposures used in the rodent bioassay. In this Commentary, we propose that the sensitivity of chemical carcinogenesis bio-assays would be enhanced by exposing rodents beginning in utero and continuing for 30 months (130 weeks) or until their natural deaths at up to about 3 years. Studies of three chemicals of different structures and uses-aspartame, cadmium, and toluene-suggest that exposing experimental animals in utero and continuing exposure for 30 months or until their natural deaths increase the sensitivity of bioassays, avoid false-negative results, and strengthen the value and validity of results for regulatory agencies. Government agencies, drug companies, and the chemical industry should conduct and compare the results of 2-year bioassays of known carcinogens or chemicals for which there is equivocal evidence of carcinogenicity with longer-term studies, with and without in utero exposure. If studies longer than 2 years and/or with in utero exposure are found to better identify potential human carcinogens, then regulatory agencies should promptly revise their testing guidelines, which were established in the 1960s and early 1970s. Changing the timing and dosing of the animal bioassay would enhance protection of workers and consumers who are exposed to potentially dangerous workplace or home contaminants, pollutants, drugs, food additives, and other chemicals throughout their lives.

The Limits of Two-Year Bioassay Exposure Regimens for Identifying Chemical Carcinogens

PubMed Central

Huff, James; Jacobson, Michael F.; Davis, Devra Lee

2008-01-01

Background Chemical carcinogenesis bioassays in animals have long been recognized and accepted as valid predictors of potential cancer hazards to humans. Most rodent bioassays begin several weeks after birth and expose animals to chemicals or other substances, including workplace and environmental pollutants, for 2 years. New findings indicate the need to extend the timing and duration of exposures used in the rodent bioassay. Objectives In this Commentary, we propose that the sensitivity of chemical carcinogenesis bio-assays would be enhanced by exposing rodents beginning in utero and continuing for 30 months (130 weeks) or until their natural deaths at up to about 3 years. Discussion Studies of three chemicals of different structures and uses—aspartame, cadmium, and toluene—suggest that exposing experimental animals in utero and continuing exposure for 30 months or until their natural deaths increase the sensitivity of bioassays, avoid false-negative results, and strengthen the value and validity of results for regulatory agencies. Conclusions Government agencies, drug companies, and the chemical industry should conduct and compare the results of 2-year bioassays of known carcinogens or chemicals for which there is equivocal evidence of carcinogenicity with longer-term studies, with and without in utero exposure. If studies longer than 2 years and/or with in utero exposure are found to better identify potential human carcinogens, then regulatory agencies should promptly revise their testing guidelines, which were established in the 1960s and early 1970s. Changing the timing and dosing of the animal bioassay would enhance protection of workers and consumers who are exposed to potentially dangerous workplace or home contaminants, pollutants, drugs, food additives, and other chemicals throughout their lives. PMID:19057693

Evaluation of the toxicity of two soils from Jales Mine (Portugal) using aquatic bioassays.

PubMed

Loureiro, Susana; Ferreira, Abel L G; Soares, Amadeu M V M; Nogueira, António J A

2005-10-01

Soil contamination can be one path for streams and groundwater contamination. As a complement of chemical analysis and total contaminants determination, bioassays can provide information on the bioavailable fraction of chemical compounds, focusing on the retention and habitat function of soils. In this study the evaluation of the toxicity of two soils from the abandoned Jales Mine (Portugal) regarded both functions. The buffer capacity of soils was tested with bioassays carried out using the cladoceran Daphnia magna and the marine bacteria Vibrio fischeri. The habitat function of soils was evaluated with the reproduction bioassay with the collembolan Folsomia candida. The Microtox solid-phase test was performed with V. fischeri using soil as test medium, and soil elutriates were extracted to perform the Microtox basic test, and an immobilization and reproduction bioassay with D. magna. The marine bacteria showed high sensitivity to the soil with low heavy metal content (JNC soil) and to JNC soil elutriates, while the soil with highest heavy metal content (JC soil) or soil elutriates exposure did not cause any toxic effect. In the bioassays with D. magna, organisms showed sensitivity to JNC and also to JC soil elutriates. Both mobilization and reproduction features were inhibited. The bioassay with F. candida did not reflect any influence of the contaminants on their reproduction. Although JNC soil presented lower heavy metal contents, elutriates showed different patterns of contamination when compared to JC soil and elutriates, which indicates different retention and buffer capacities between soils. Results obtained in this study underlined the sensitivity and importance of soil elutriate bioassays with aquatic organisms in the evaluation strategy in soil ERA processes.

Analysis of the sensitivity of in vitro bioassays for androgenic, progestagenic, glucocorticoid, thyroid and estrogenic activity: Suitability for drinking and environmental waters.

PubMed

Leusch, Frederic D L; Neale, Peta A; Hebert, Armelle; Scheurer, Marco; Schriks, Merijn C M

2017-02-01

The presence of endocrine disrupting chemicals in the aquatic environment poses a risk for ecosystem health. Consequently there is a need for sensitive tools, such as in vitro bioassays, to monitor endocrine activity in environmental waters. The aim of the current study was to assess whether current in vitro bioassays are suitable to detect endocrine activity in a range of water types. The reviewed assays included androgenic (n=11), progestagenic (n=6), glucocorticoid (n=5), thyroid (n=5) and estrogenic (n=8) activity in both agonist and antagonist mode. Existing in vitro bioassay data were re-evaluated to determine assay sensitivity, with the calculated method detection limit compared with measured hormonal activity in treated wastewater, surface water and drinking water to quantify whether the studied assays were sufficiently sensitive for environmental samples. With typical sample enrichment, current in vitro bioassays are sufficiently sensitive to detect androgenic activity in treated wastewater and surface water, with anti-androgenic activity able to be detected in most environmental waters. Similarly, with sufficient enrichment, the studied mammalian assays are able to detect estrogenic activity even in drinking water samples. Fewer studies have focused on progestagenic and glucocorticoid activity, but some of the reviewed bioassays are suitable for detecting activity in treated wastewater and surface water. Even less is known about (anti)thyroid activity, but the available data suggests that the more sensitive reviewed bioassays are still unlikely to detect this type of activity in environmental waters. The findings of this review can help provide guidance on in vitro bioassay selection and required sample enrichment for optimised detection of endocrine activity in environmental waters. Copyright © 2016 Elsevier Ltd. All rights reserved.

A new P. putida instrumental toxicity bioassay.

PubMed

Figueredo, Federico; Abrevaya, Ximena C; Cortón, Eduardo

2015-05-01

Here, we present a new toxicity bioassay (CO2-TOX), able to detect toxic or inhibitory compounds in water samples, based on the quantification of Pseudomonas putida KT2440 CO2 production. The metabolically produced CO2 was measured continuously and directly in the liquid assay media, with a potentiometric gas electrode. The optimization studies were performed using as a model toxicant 3,5-DCP (3,5-dichlorophenol); later, heavy metals (Pb(2+), Cu(2+), or Zn(2+)) and a metalloid (As(5+)) were assayed. The response to toxics was evident after 15 min of incubation and at relatively low concentrations (e.g., 1.1 mg/L of 3,5-DCP), showing that the CO2-TOX bioassay is fast and sensitive. The EC50 values obtained were 4.93, 0.12, 6.05, 32.17, and 37.81 mg/L for 3,5-DCP, Cu(2+), Zn(2+), As(5+), and Pb(2+), respectively, at neutral pH. Additionally, the effect of the pH of the sample and the use of lyophilized bacteria were also analyzed showing that the bioassay can be implemented in different conditions. Moreover, highly turbid samples and samples with very low oxygen levels were measured successfully with the new instrumental bioassay described here. Finally, simulated samples containing 3,5-DCP or a heavy metal mixture were tested using the proposed bioassay and a standard ISO bioassay, showing that our test is more sensible to the phenol but less sensible to the metal mixtures. Therefore, we propose CO2-TOX as a rapid, sensitive, low-cost, and robust instrumental bioassay that could perform as an industrial wastewater-process monitor among other applications.

Biomonitoring of cyanotoxins in two tropical reservoirs by cladoceran toxicity bioassays.

PubMed

da S Ferrão-Filho, Aloysio; Soares, Maria Carolina S; de Freitas Magalhães, Valeria; Azevedo, Sandra M F O

2009-02-01

This study evaluates the potential for the use of cladocerans in biomonitoring of cyanobacterial toxins. Two zooplankton species (Daphnia gessneri and Moina micrura) were cultivated in the laboratory for use in acute (48 h) and chronic (10 days) bioassays. Water samples were collected from two reservoirs and diluted in mineral water at four concentrations. Survivorship in the acute bioassays was used to calculate LC50, and survivorship and fecundity in chronic bioassays were used to calculate the intrinsic population growth rate (r) and the EC50. Analysis of phytoplankton in the water samples from one reservoir revealed that cyanobacteria were the dominant group, represented by the genera Anabaena, Cylindrospermopsis, and Microcystis. Results of bioassays showed adverse effects including death, paralysis, and reduced population growth rate, generally proportional to the reservoir water concentration. These effects may be related to the presence of cyanobacteria toxins (microcystins or saxitoxins) in the water.

Formulation and application of methoxychlor for elm bark beetle control

Treesearch

R. A. Cuthbert; J. H. Barger; A. C. Lincoln; P. A. Reed

1973-01-01

American elm trees, Ulmus americana L., were sprayed with different formulations of methoxychlor by mistblower, hydraulic sprayer or helicopter. Twig-crotches were collected from sprayed trees for GLC assay and Scolytus multistriatus (Marsham) bioassay. Hydraulic deposits were heaviest but the mistblower was more efficient in terms...

Comparative efficacy of selected insecticide alternatives for boll weevil (Coleoptera: Curculionidae) control using laboratory bioassays

USDA-ARS?s Scientific Manuscript database

The boll weevil, Anthonomus grandis grandis (Boheman), is a major cotton pest responsible for an estimated $300 million in annual crop losses. Boll weevil eradication programs depend on malathion ULV to achieve and maintain eradication status. Should this effective and economical insecticide become ...

Laboratory evaluations of Lepidopteran-active soybean seed treatments on survivorship of fall armyworm (Lepidoptera:Noctuidae) larvae

USDA-ARS?s Scientific Manuscript database

Two anthranilic diamide insecticides, chlorantraniliprole and cyantraniliprole, were evaluated as soybean, Glycine max L., seed treatments for control of fall armyworm, Spodoptera frugiperda (J. E. Smith). Bioassays were conducted using 2nd instar larvae and plants from both field and greenhouse gr...

INDUCTION OF SKIN PAPILLOMAS IN THE SENCAR MOUSE AS A TIER 2 CARCINOGENESIS BIOASSAY

EPA Science Inventory

The Toxic Substances Control Act mandates the testing of industrial chemicals for which insufficient evidence of safety exists. One of the more critical areas in chemical carcinogenesis testing is a dependable approach to confirmatory tests (tier 2) of identified positives at a s...

Toxicity of selected insecticides to onion thrips (Thysanoptera: Thripidae) using a glass-vial bioassay

USDA-ARS?s Scientific Manuscript database

Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), are important pests that are primarily controlled with insecticides on both onions and cotton in the Lower Rio Grande Valley of Texas. Resistance to various insecticides has been reported so data are needed on toxicity of insecticides r...

Rapid bioassay to screen potential biopesticides in Tenebrio molitor larvae

USDA-ARS?s Scientific Manuscript database

A simplified assay was devised to evaluate the response of Tenebrio molitor larvae to potential insect control products. The assay incorporates punched disks of flattened whole-grain bread placed in 96-well plates, with treatments applied topically, and neonate larvae added to each well. To evalua...

Mitochondrial activity in fern spores of Cyathea costaricensis as an indicator of the impact of land use and water quality in rivers running through cloud forests.

PubMed

Rodríguez-Romero, Alexis Joseph; Rico-Sánchez, Axel Eduardo; Catalá, Myriam; Sedeño-Díaz, Jacinto Elías; López-López, Eugenia

2017-12-01

Early-warning biomarkers, such as mitochondrial activity, have become a key tool in ecosystem assessment. This study aims to evaluate the response of mitochondrial activity in spores of the autochthonous fern Cyathea costaricensis as a bioassessment tool concurrently with land use and physicochemical evaluation in 11 sites along Bobos River, Veracruz, Mexico, to assess river water quality. Bobos River is located in the Nautla basin, northeastern Veracruz (Mexico); the upper river runs through a protected natural area (Filobobos River and adjacent areas). The study involved three monitoring periods: February, June and September 2014. In each study site, physicochemical water quality parameters were recorded to calculate the Water Quality Index (WQI); also, study sites were characterized in terms of land use. Water samples were collected to perform bioassays where spores of C. costaricensis were exposed to samples to assess mitochondrial activity; a positive control exposure test was run under controlled conditions to maximize mitochondrial activity. A Principal Component Analysis was performed to correlate land-use attributes with environmental variables and mitochondrial activity. Three river sections were identified: the upper portion was characterized by the dominance of native vegetation, the highest WQI (in September), and the lowest mitochondrial activity (63.87%-77.47%), related to the geological nature of the basin and high hardness levels. Mitochondrial activity peaked in September (98.32% ± 9.01), likely resulting from nutrient enrichment in the rainy season, and was lowest in February (74.54% ± 1.60) (p < 0.05). Mitochondrial activity was found to be a good benchmark for the assessment of water quality, reflecting the effects of physicochemical characteristics. Mitochondrial activity showed changes along the river and between seasons, associated with environmental characteristics such as land use and the geological nature of the basin, as well as with those related to human impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

National post-market surveillance assessment of veterinary medicines in Korea during the past decade.

PubMed

Kang, JeongWoo; Park, Hae-Chul; Jang, Yang Ho; Hossain, Md Akil; Jeong, Kyunghun; Jeong, Mi Young; Yun, Seon-Jong; Park, Sung-Won; Kim, Dae Gyun; Lee, Kwang-Jick

2017-05-22

Veterinary medicines have been widely used for the prevention and treatment of diseases, growth promotion, and to promote feeding efficacy in livestock. As the veterinary medicine industry has steadily grown, it is crucial to set up a baseline for the quality of medicine as well as the insufficiency or excessiveness of the active ingredients in drug products to ensure the compliance, safety and efficacy of these medicines. Thus, the 10 years data of post-marketing quality control study was summarized to determine the rate and extent of non-compliance of these medicines and to establish baseline data for future quality control measures of veterinary medicine. In this study, 1650 drugs for veterinary use were collected per year from each city and province in Korea and analysed for the quantity of active ingredients according to the "national post-market surveillance (NPMS) system" over the past decade. The NPMS assessment was performed using liquid and gas chromatography, titration, UV/Vis spectrophotometry, and bioassays. A total of 358 cases were deemed noncompliant, with the average noncompliance rate for all medicine types being 2.0%. The average noncompliance rates for antibiotics, biologics and other chemical drugs except antibiotics (OCD) were 1.1%, 1.2%, and 3.0%, respectively. The first leading cause for noncompliant products was insufficient quantity of major ingredients (283 cases), and the second leading cause was the existence of excess amount of active ingredients (60 cases). Tylosin, spiramycin, ampicillin, tetracyclines and penicillins were most frequently found to be noncompliant among antibiotics. Among the OCD, the noncompliance was found commonly in vitamin A. The overall trend presented gradually decreasing violation rates, suggesting that the quality of veterinary medicines has improved. Consistent application of the NPMS assessment and the establishment of the Korea Veterinary Good Manufacturing Practice (KVGMP) will help to maintain the good quality of medicine.

Assessing Insecticide Susceptibility of Laboratory Lutzomyia longipalpis and Phlebotomus papatasi Sand Flies (Diptera: Psychodidae: Phlebotominae).

PubMed

Denlinger, David S; Lozano-Fuentes, Saul; Lawyer, Phillip G; Black, William C; Bernhardt, Scott A

2015-09-01

Chemical insecticides are effective for controlling Lutzomyia and Phlebotomus sand fly (Diptera: Psychodidae) vectors of Leishmania parasites. However, repeated use of certain insecticides has led to tolerance and resistance. The objective of this study was to determine lethal concentrations (LCs) and lethal exposure times (LTs) to assess levels of susceptibility of laboratory Lutzomyia longipalpis (Lutz and Nieva) and Phlebotomus papatasi (Scopoli) to 10 insecticides using a modified version of the World Health Organization (WHO) exposure kit assay and Centers for Disease Control and Prevention (CDC) bottle bioassay. Sand flies were exposed to insecticides coated on the interior of 0.5-gallon and 1,000-ml glass bottles. Following exposure, the flies were allowed to recover for 24 h, after which mortality was recorded. From dose-response survival curves for L. longipalpis and P. papatasi generated with the QCal software, LCs causing 50, 90, and 95% mortality were determined for each insecticide. The LCs and LTs from this study will be useful as baseline reference points for future studies using the CDC bottle bioassays to assess insecticide susceptibility of sand fly populations in the field. There is a need for a larger repository of sand fly insecticide susceptibility data from the CDC bottle bioassays, including a range of LCs and LTs for more sand fly species with more insecticides. Such a repository would be a valuable tool for vector management. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Efficacy of spray formulations containing binary mixtures of clove and eucalyptus oils against susceptible and pyrethroid/ malathion-resistant head lice (Anoplura: Pediculidae).

PubMed

Choi, Han-Young; Yang, Young-Cheol; Lee, Si Hyeock; Clark, J Marshall; Ahn, Young-Joon

2010-05-01

The control efficacy of clove, Eugenia caryophyllata, and eucalyptus, Eucalyptus globulus, essential oils and 15 formulations containing these essential oils alone (8, 12, and 15% sprays) and their binary mixtures (7:3, 5:5, and 3:7 by weight) against adult females of insecticide-susceptible KR-HL and dual malathion- and permethrin-resistant BR-HL strains of head louse, Pediculus humanus capitis (De Geer), was examined by using contact plus fumigant and human hair wig (placed over the head of mannequin) mortality bioassays. In contact plus fumigant mortality bioassay, essential oils from eucalyptus (0.225 mg/cm2) and clove (1.149 mg/cm2) were less effective than either d-phenothrin (0.0029 mg/cm2) or pyrethrum (0.0025 mg/cm2) based on 6-h median lethal concentration values. However, the efficacies of eucalyptus and clove oils were almost identical against females fromn both strains, despite high levels of resistance of the BR-HL females to d-phenothrin (resistance ratio, 667) and pyrethrum (resistance ratio, 754). In human hair wig mortality bioassay, eucalyptus oil spray treatment gave better control efficacy than either spray treatment with clove oil alone or their binary mixtures. Thus, eucalyptus applied as 8% sprays (15 or 20 ml) appears to provide effective protection against pediculosis even to insecticide-resistant head louse populations. Once the safety issues resolved, covering the treated hair and scalp with bath shower cap or hat would ensure the fumigant action of the essential oil.

Inhibition of seedling survival under Rhododendron maximum (Ericaceae): could allelopathy be a cause?

PubMed

Nilsen, E T; Walker, J F; Miller, O K; Semones, S W; Lei, T T; Clinton, B D

1999-11-01

In the southern Appalachian mountains a subcanopy species, Rhododendron maximum, inhibits the establishment and survival of canopy tree seedlings. One of the mechanisms by which seedlings could be inhibited is an allelopathic effect of decomposing litter or leachate from the canopy of R. maximum (R.m.) on seed germination, root elongation, or mycorrhizal colonization. The potential for allelopathy by R.m. was tested with two bioassay species (lettuce and cress), with seeds from four native tree species, and with three ectomycorrhizal fungi. Inhibitory influences of throughfall, fresh litter, and decomposed litter (organic layer) from forest with R.m. (+R.m. sites) were compared to similar extractions made from forest without R.m. (-R.m. sites). Throughfall and leachates of the organic layer from both +R.m. and -R.m. sites stimulated germination of the bioassay species above that of the distilled water control, to a similar extent. There was an inhibitory effect of leachates of litter from +R.m. sites on seed germination and root elongation rate of both bioassay species compared with that of litter from -R.m. sites. Native tree seed stratified in forest floor material from both forest types had a slightly higher seed germination rate compared with the control. A 2-yr study of seed germination and seedling mortality of two tree species, Quercus rubra and Prunus serotina, in field plots showed no significant influence of litter or organic layer from either forest type. Incorporating R.m. leaf material into the growth medium in vitro depressed growth of one ectomycorrhizal species but did not affect two other species. Leaf material from other deciduous tree species depressed ectomycorrhizal growth to a similar or greater extent as leaf material from R.m. In conclusion, R.m. litter can have an allelopathic effect on seed germination and root elongation of bioassay species as well as some ectomycorrhizal species. However, this allelopathic affect is not manifest in field sites and is not likely to be an important cause for the inhibition of seedling survival within thickets of R.m.

9 CFR 147.16 - Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment).

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Procedure for the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). 147.16 Section 147.16 Animals and Animal Products... the evaluation of mycoplasma reactors by in vivo bio-assay (enrichment). This procedure has been shown...

9 CFR 147.6 - Procedure for determining the status of flocks reacting to tests for Mycoplasma gallisepticum...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Agency may examine reactors by the in vivo bio-assay, PCR-based procedures, and/or culture procedures before final determination of the flock status is made. (13) If the in vivo bio-assay, PCR-based... classification for which it was tested. (14) If the in vivo bio-assay, PCR-based procedures, or culture...

A bioaccumulation bioassay for freshwater sediments

USGS Publications Warehouse

Mac, Michael J.; Noguchi, George E.; Hesselberg, Robert J.; Edsall, Carol C.; Shoesmith, John A.; Bowker, James D.

1990-01-01

A laboratory bioassay is described for determining the bioavailability of contaminants from freshwater sediments. The bioassay consists of 10-d exposures to whole sediments under flow-through conditions. After testing five species, the fathead minnow (Pimephales promelas) and the earthworm (Lubricus terrestris) were recommended for use in the test. When the availability of polychlorinated biphenyls (PCBs), Hg and Zn from Great Lakes sediments was examined in laboratory exposures, only the PCBs were accumulated. A field validation study demonstrated that the magnitude of accumulation in laboratory exposures was similar to that in organisms caged in the field. A protocol is recommended for using the test as a standardized bioaccumulation bioassay.

Assessing the ecological risk of soil irrigated with wastewater using in vitro cell bioassays.

PubMed

Yu, Guo; Xiao, Ruiyang; Wang, Donghong; Zhou, Jun; Wang, Zijian

2008-12-01

In the most recent research work, the accumulation of toxicants in soil was always assessed through concentration level of the target contaminants. However, assessments based on chemical analysis were limited in numbers and in their unpredictable bioavailability. An alternative assessment could be based on toxicity assessment. It means that a screening bioassay is a necessary tool for identifying and defining contaminants at the sites, which should warrant further attention. In the present study, three in vitro cell bioassays, including the SOS/umu bioassay for genotoxic effects, human estrogen receptor recombinant yeast bioassay for estrogenic effects, and ethoxyresorfin O-deethylase (EROD) with H4IIE rat hepatoma cells bioassay for Ah-receptor agonistic effects, were used for the evaluation of the accumulation of toxicants in soils irrigated with wastewater in the suburb of Beijing, China. The results indicated that there were significant increases of genotoxic, estrogenic, and Ah-receptor agonistic effects in soils irrigated with wastewater, as compared with soils irrigated with groundwater. There was the decreased effect gradient following the increase of the distances from the inlet of the wastewater. It was concluded that wastewater irrigation could cause accumulation of genotoxic, estrogenic, and Ah-receptor agonistic chemicals in soil.

Sensitivity assessment of sea lice to chemotherapeutants: Current bioassays and best practices.

PubMed

Marín, S L; Mancilla, J; Hausdorf, M A; Bouchard, D; Tudor, M S; Kane, F

2017-12-18

Traditional bioassays are still necessary to test sensitivity of sea lice species to chemotherapeutants, but the methodology applied by the different scientists has varied over time in respect to that proposed in "Sea lice resistance to chemotherapeutants: A handbook in resistance management" (2006). These divergences motivated the organization of a workshop during the Sea Lice 2016 conference "Standardization of traditional bioassay process by sharing best practices." There was an agreement by the attendants to update the handbook. The objective of this article is to provide a baseline analysis of the methodology for traditional bioassays and to identify procedures that need to be addressed to standardize the protocol. The methodology was divided into the following steps: bioassay design; material and equipment; sea lice collection, transportation and laboratory reception; preparation of dilution; parasite exposure; response evaluation; data analysis; and reporting. Information from the presentations of the workshop, and also from other studies, allowed for the identification of procedures inside a given step that need to be standardized as they were reported to be performed differently by the different working groups. Bioassay design and response evaluation were the targeted steps where more procedures need to be analysed and agreed upon. © 2017 John Wiley & Sons Ltd.

Alkaline phosphatase activity-guided isolation of active compounds and new dammarane-type triterpenes from Cissus quadrangularis hexane extract.

PubMed

Pathomwichaiwat, Thanika; Ochareon, Pannee; Soonthornchareonnon, Noppamas; Ali, Zulfiqar; Khan, Ikhlas A; Prathanturarug, Sompop

2015-02-03

The stem of Cissus quadrangularis L. (CQ) is used in traditional medicine to treat bone fractures and swelling. Anti-osteoporotic activity of CQ hexane extract has been reported, but the active compounds in this extract remain unknown. Thus, we aimed to identify the active compounds in CQ hexane extract using bioassay-guided isolation. The CQ hexane extract was fractionated sequentially with benzene, dichloromethane, ethyl acetate, and methanol. The examination of CQ extract and its fractions was guided by bioassays for alkaline phosphatase (ALP) activity during the differentiation of MC3T3-E1 osteoblastic cells. The cells were treated with or without the CQ extract and its fractions for a period of time, and then the stimulatory effect of the alkaline phosphatase enzyme, a bone differentiation marker, was investigated. The compounds obtained were structurally elucidated using spectroscopic techniques and re-evaluated for activity during bone differentiation. A total of 29 compounds were isolated, viz., triterpenes, fatty acid methyl esters, glycerolipids, steroids, phytols, and cerebrosides. Four new dammarane-type triterpenes were isolated for the first time from nature, and this report is the first to identify this group of compounds from the Vitaceae family. Seven compounds, viz., glycerolipids and squalene, stimulated ALP activity at a dose of 10μg/mL. Moreover, the synergistic effect of these compounds on bone formation was demonstrated. This report describes, for the first time, the isolation of active compounds from CQ hexane extract; these active compounds will be useful for the quality control of extracts from this plant used to treat osteoporosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Spatial and temporal patterns of surface water quality and ichthyotoxicity in urban and rural river basins in Texas

USGS Publications Warehouse

VanLandeghem, Matthew M.; Meyer, Matthew D.; Cox, Stephen B.; Sharma, Bibek; Patino, Reynaldo

2012-01-01

The Double Mountain Fork Brazos River (Texas, USA) consists of North (NF) and South Forks (SF). The NF receives urban runoff and twice-reclaimed wastewater effluent, whereas the SF flows through primarily rural areas. The objective of this study was to determine and compare associations between standard water quality variables and ichthyotoxicity at a landscape scale that included urban (NF) and rural (SF) sites. Five NF and three SF sites were sampled quarterly from March 2008 to March 2009 for specific conductance, salinity, hardness, pH, temperature, and turbidity; and a zebrafish (Danio rerio) embryo bioassay was used to determine ichthyotoxicity. Metal and nutrient concentrations at all sites were also measured in addition to standard water quality variables in spring 2009. Principal component analyses identified hardness, specific conductance, and salinity as the water variables that best differentiate the urban NF (higher levels) from rural SF habitat. Nutrient levels were also higher in the NF, but no landscape scale patterns in metal concentrations were observed. Ichthyotoxicity was generally higher in NF water especially in winter, and multiple regression analyses suggested a positive association between water hardness and ichthyotoxicity. To test for the potential influence of the toxic golden alga (Prymnesium parvum) on overall ichthyotoxicity, a cofactor known to enhance golden alga toxin activity was used in the bioassays. Golden alga ichthyotoxicity was detected in the NF but not the SF, suggesting golden alga may have contributed to overall ichthyotoxicity in the urban but not in the rural system. In conclusion, the physicochemistry of the urban-influenced NF water was conducive to the expression of ichthyotoxicity and also point to water hardness as a novel factor influencing golden alga ichthyotoxicity in surface waters.

Integrated approach to assess ecosystem health in harbor areas.

PubMed

Bebianno, M J; Pereira, C G; Rey, F; Cravo, A; Duarte, D; D'Errico, G; Regoli, F

2015-05-01

Harbors are critical environments with strategic economic importance but with potential environmental impact: health assessment criteria are a key issue. An ecosystem health status approach was carried out in Portimão harbor as a case-study. Priority and specific chemical levels in sediments along with their bioavailability in mussels, bioassays and a wide array of biomarkers were integrated in a biomarker index (IBR index) and the overall data in a weight of evidence (WOE) model. Metals, PAHs, PCBs and HCB were not particularly high compared with sediment guidelines and standards for dredging. Bioavailability was evident for Cd, Cu and Zn. Biomarkers proved more sensitive namely changes of antioxidant responses, metallothioneins and vittellogenin-like proteins. IBR index indicated that site 4 was the most impacted area. Assessment of the health status by WOE approach highlighted the importance of integrating sediment chemistry, bioaccumulation, biomarkers and bioassays and revealed that despite some disturbance in the harbor area, there was also an impact of urban effluents from upstream. Environmental quality assessment in harbors. Copyright © 2015 Elsevier B.V. All rights reserved.

Studies on the carriage and transmission of porcine reproductive and respiratory syndrome virus by individual houseflies (Musca domestica).

PubMed

Otake, S; Dee, S A; Moon, R D; Rossow, K D; Trincado, C; Pijoan, C

2004-01-17

The objectives of the study were to determine the site of porcine reproductive and respiratory syndrome virus (PRRSV) in individual houseflies, to assess whether an individual housefly could transmit PRRSV to a susceptible pig, and to compare the ability of PCR, virus isolation and a pig bioassay to detect PRRSV in houseflies. In the first experiment 26 houseflies were fed on a pig infected experimentally with PRRSV; 13 were processed as a whole fly homogenate, while an exterior surface wash and a gut homogenate were collected from the other 13. Infectious PRRSV was recovered from nine of the whole fly homogenates, 12 of the gut homogenates and one of the exterior surface washes. In the second experiment, two of 10 individual houseflies, which had fed on an infected pig, transmitted PRRSV to a susceptible pig in a controlled manual transmission protocol. In the third experiment, single flies or pools of 30 flies were immersed in different concentrations of a PRRSV inoculum, then tested by PCR, virus isolation and bioassay. The virus was detected at a concentration of 10(1) TCID50/ml by PCR, 10(2) TCID50/ml by the bioassay and 10(3) TCID50/ml by virus isolation.

Light-Addressed Electrodeposition of Enzyme-Entrapped Chitosan Membranes for Multiplexed Enzyme-Based Bioassays Using a Digital Micromirror Device

PubMed Central

Huang, Shih-Hao; Wei, Lu-Shiuan; Chu, Hsiao-Tzu; Jiang, Yeu-Long

2013-01-01

This paper describes a light-addressed electrolytic system used to perform an electrodeposition of enzyme-entrapped chitosan membranes for multiplexed enzyme-based bioassays using a digital micromirror device (DMD). In this system, a patterned light illumination is projected onto a photoconductive substrate serving as a photo-cathode to electrolytically produce hydroxide ions, which leads to an increased pH gradient. The high pH generated at the cathode can cause a local gelation of chitosan through sol-gel transition. By controlling the illumination pattern on the DMD, a light-addressed electrodeposition of chitosan membranes with different shapes and sizes, as well as multiplexed micropatterning, was performed. The effect of the illumination time of the light pattern on the dimensional resolution of chitosan membrane formation was examined experimentally. Moreover, multiplexed enzyme-based bioassay of enzyme-entrapped chitosan membranes was also successfully demonstrated through the electrodeposition of the chitosan membranes with various shapes/sizes and entrapping different enzymes. As a model experiment, glucose and ethanol were simultaneously detected in a single detection chamber without cross-talk using shape-coded chitosan membranes entrapped with glucose oxidase (GOX), peroxidase (POD), and Amplex Red (AmR) or alcohol oxidase (AOX), POD, and AmR by using same fluorescence indicator (AmR). PMID:23959236

Light-addressed electrodeposition of enzyme-entrapped chitosan membranes for multiplexed enzyme-based bioassays using a digital micromirror device.

PubMed

Huang, Shih-Hao; Wei, Lu-Shiuan; Chu, Hsiao-Tzu; Jiang, Yeu-Long

2013-08-16

This paper describes a light-addressed electrolytic system used to perform an electrodeposition of enzyme-entrapped chitosan membranes for multiplexed enzyme-based bioassays using a digital micromirror device (DMD). In this system, a patterned light illumination is projected onto a photoconductive substrate serving as a photo-cathode to electrolytically produce hydroxide ions, which leads to an increased pH gradient. The high pH generated at the cathode can cause a local gelation of chitosan through sol-gel transition. By controlling the illumination pattern on the DMD, a light-addressed electrodeposition of chitosan membranes with different shapes and sizes, as well as multiplexed micropatterning, was performed. The effect of the illumination time of the light pattern on the dimensional resolution of chitosan membrane formation was examined experimentally. Moreover, multiplexed enzyme-based bioassay of enzyme-entrapped chitosan membranes was also successfully demonstrated through the electrodeposition of the chitosan membranes with various shapes/sizes and entrapping different enzymes. As a model experiment, glucose and ethanol were simultaneously detected in a single detection chamber without cross-talk using shape-coded chitosan membranes entrapped with glucose oxidase (GOX), peroxidase (POD), and Amplex Red (AmR) or alcohol oxidase (AOX), POD, and AmR by using same fluorescence indicator (AmR).

A mutation (L1014F) in the voltage-gated sodium channel of the grain aphid, Sitobion avenae, is associated with resistance to pyrethroid insecticides.

PubMed

Foster, Stephen P; Paul, Verity L; Slater, Russell; Warren, Anne; Denholm, Ian; Field, Linda M; Williamson, Martin S

2014-08-01

The grain aphid, Sitobion avenae Fabricius (Hemiptera: Aphididae), is an important pest of cereal crops. Pesticides are the main method for control but carry the risk of selecting for resistance. In response to reports of reduced efficacy of pyrethroid sprays applied to S. avenae, field samples were collected and screened for mutations in the voltage-gated sodium channel, the primary target site for pyrethroids. Aphid mobility and mortality to lambda-cyhalothrin were measured in coated glass vial bioassays. A single amino acid substitution (L1014F) was identified in the domain IIS6 segment of the sodium channel from the S. avenae samples exhibiting reduced pyrethroid efficacy. Bioassays on aphids heterozygous for the kdr mutation (SR) or homozygous for the wild-type allele (SS) showed that those carrying the mutation had significantly lower susceptibility to lambda-cyhalothrin. The L1014F (kdr) mutation, known to confer pyrethroid resistance in many insect pests, has been identified for the first time in S. avenae. Clonal lines heterozygous for the mutation showed 35-40-fold resistance to lambda-cyhalothrin in laboratory bioassays, consistent with the reported effect of this mutation on pyrethroid sensitivity in other aphid species. © 2013 Society of Chemical Industry.

Schistosomin: a pronase-sensitive agent in the hemolymph of Trichobilharzia ocellata-infected Lymnaea stagnalis inhibits the activity of albumen glands in vitro.

PubMed

Joosse, J; van Elk, R; Mosselman, S; Wortelboer, H; van Diepen, J C

1988-01-01

The schistosome parasite, Trichobilharzia ocellata, nearly completely inhibits the reproductive activity of its intermediate host, Lymnaea stagnalis. The synthetic activity of albumen glands of infected snails at day 35 postinfection (p.i.) is only 1% of the control value. The parasite acts by humoral means. We tested the hypothesis that (a) specific humoral agent(s) is (are) involved and refer to this (these) agent(s) as schistosomin. The presence of schistosomin in the hemolymph of infected snails was investigated by using galactogen synthesis in albumen glands as an in vitro bioassay. The synthetic activity of albumen glands of noninfected snails decreased by about 50% during a 1-h incubation in the hemolymph of infected snails. This inhibition is attributed to schistosomin. Based on these results, with the present bioassay schistosomin appears in the hemolymph between days 28-36 p.i. onwards. Schistosomin is heat-stable (100 degrees C) and pronase-sensitive, and therefore it might have a peptide nature. Schistosomin suppresses the stimulating action of the female, gonadotrophic dorsal body hormone at relatively low doses, which suggests that it may compete with this hormone for the same receptors. The development of two other bioassays for schistosomin in our laboratory is discussed.

Impact of Processing on the Protein Quality of Pinto Bean (Phaseolus vulgaris) and Buckwheat (Fagopyrum esculentum Moench) Flours and Blends, As Determined by in Vitro and in Vivo Methodologies.

PubMed

Nosworthy, Matthew G; Franczyk, Adam; Zimoch-Korzycka, Anna; Appah, Paulyn; Utioh, Alphonsus; Neufeld, Jason; House, James D

2017-05-17

Blending of protein sources can increase protein quality by compensating for limiting amino acids present in individual sources, whereas processing grain flours by extrusion or baking can also alter protein quality. To determine the effect of baking and extrusion on the protein quality of blended flours from buckwheat and pinto beans, a rodent bioassay was performed and compared to an in vitro method of protein quality determination. Overall, extruded products had higher protein efficiency ratio values, increased digestibility, and greater protein digestibility corrected amino acid score (PDCAAS) values than baked products, with the extruded buckwheat/pinto blend having the greatest PDCAAS value of the experimental diets investigated. A correlation was found between both digestibility and PDCAAS values generated from in vitro and in vivo methods. The use of in vitro digestibility analysis should be investigated as a potential replacement for the current rodent assay for nutrient content claim purposes.

Plant genotoxicity: a molecular cytogenetic approach in plant bioassays.

PubMed

Maluszynska, Jolanta; Juchimiuk, Jolanta

2005-06-01

It is important for the prevention of DNA changes caused by environment to understand the biological consequences of DNA damages and their molecular modes of action that lead to repair or alterations of the genetic material. Numerous genotoxicity assay systems have been developed to identify DNA reactive compounds. The available data show that plant bioassays are important tests in the detection of genotoxic contamination in the environment and the establishment of controlling systems. Plant system can detect a wide range of genetic damage, including gene mutations and chromosome aberrations. Recently introduced molecular cytogenetic methods allow analysis of genotoxicity, both at the chromosomal and DNA level. FISH gives a new possibility of the detection and analysis of chromosomal rearrangements in a great detail. DNA fragmentation can be estimated using the TUNEL test and the single cell gel electrophoresis (Comet assay).

Sex-pairing pheromone in the Asian termite pest species Odontotermes formosanus.

PubMed

Wen, Ping; Ji, Bao-Zhong; Liu, Shu-Wen; Liu, Cong; Sillam-Dussès, David

2012-05-01

The sex-pairing pheromone of the black winged subterranean termite, Odontotermes formosanus (Shiraki) (Isoptera, Termitidae), was investigated using headspace-SPME, GC-MS, GC-EAD, and attraction bioassays. Females secrete the pheromone from their sternal gland to attract males. The sex-pairing pheromone is composed of (Z,Z)-dodeca-3,6-dien-1-ol and (Z)-dodec-3-en-1-ol, estimated at 9 to 16.64 ng and 0.2 to 0.54 ng, respectively. Both short- and long-distance sex attraction bioassays were employed to show that these compounds act in synergy at long distance, but only (Z,Z)-dodeca-3,6-dien-1-ol is active at short distance. The pheromone may be useful in efforts to control this pest, which is considered one of the most harmful termite species in Southeast Asia.

Orthogonal Assessment of Biotherapeutic Glycosylation: A Case Study Correlating N-Glycan Core Afucosylation of Herceptin with Mechanism of Action.

PubMed

Upton, Rosie; Bell, Leonard; Guy, Colin; Caldwell, Paul; Estdale, Sian; Barran, Perdita E; Firth, David

2016-10-18

In the development of therapeutic antibodies and biosimilars, an appropriate biopharmaceutical CMC control strategy that connects critical quality attributes with mechanism of action should enable product assessment at an early stage of development in order to mitigate risk. Here we demonstrate a new analytical workflow using trastuzumab which comprises "middle-up" analysis using a combination of IdeS and the endoglycosidases EndoS and EndoS2 to comprehensively map the glycan content. Enzymatic cleavage between the two N-acetyl glucosamine residues of the chitobiose core of N-glycans significantly simplifies the oligosaccharide component enabling facile distinction of GlcNAc from GlcNAc with core fucose. This approach facilitates quantitative determination of total Fc-glycan core-afucosylation, which was in turn correlated with receptor binding affinity by surface plasmon resonance and in vitro ADCC potency with a cell based bioassay. The strategy also quantifies Fc-glycan occupancy and the relative contribution from high mannose glycans.

Technical basis for internal dosimetry at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

1991-07-01

The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products ({sup 58}Co, {sup 60}Co, {sup 54}Mn, and {sup 59}Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium,. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation and bioassay follow-up treatment. 78more » refs., 35 figs., 115 tabs.« less

Technical basis for internal dosimetry at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sula, M.J.; Carbaugh, E.H.; Bihl, D.E.

1989-04-01

The Hanford Internal Dosimetry Program, administered by Pacific Northwest Laboratory for the US Department of Energy, provides routine bioassay monitoring for employees who are potentially exposed to radionuclides in the workplace. This report presents the technical basis for routine bioassay monitoring and the assessment of internal dose at Hanford. The radionuclides of concern include tritium, corrosion products (/sup 58/Co, /sup 60/Co, /sup 54/Mn, and /sup 59/Fe), strontium, cesium, iodine, europium, uranium, plutonium, and americium. Sections on each of these radionuclides discuss the sources and characteristics; dosimetry; bioassay measurements and monitoring; dose measurement, assessment, and mitigation; and bioassay follow-up treatment. 64more » refs., 42 figs., 118 tabs.« less

Influence of a mineral insecticide particle size on bait efficacy against Reticulitermes flavipes (Isoptera: Rhinotermitidae)

Treesearch

Thomas g. Shelton; Laurent Cartier; Terence L. Wagner; Christian Becker

2007-01-01

We examined the efficacy of termiticidal baits comprised of powdered acellulose and a mineral insecticide, cryolite crystals, in laboratory bioassays against pseudergates of Eastern subterranean termites [Reticulitermes flavipes (Kollar)]. The influence of cryolite crystal size [0 (control), 0.2, and 20 pm diameter particles] on the overall mortality...

A Standardized and Portable Field Bioassay to Evaluate Interior Residual Sprays for Control of Malaria

DTIC Science & Technology

2008-10-01

by exports of marine products, citrus, sugar cane, and bananas (CIA Factbook 2008). The occurrence of malaria in Belize is generally lower in...chemical compounds (similar to the natural chemical pyrethrins which come from Chrysanthemum spp. flowers ) that are recommended by the WHO for use

SYNTHETIC-BASED DRILLING FLUIDS: AN ASSESSMENT OF THE SPATIAL DISTRIBUTION OF TOXICANTS IN SEDIMENTS FROM GULF OF MEXICO DRILLING PLATFORMS

EPA Science Inventory

Use of the amphipods, Leptocheirus plumulosus and Ampelisca abdita, in these bioassays presented no major difficulties in the execution of these test protocols. Sensitivity to the toxicants was exhibited by L. plumulosus and survival of control animals was good suggesting the sui...

Results of bulk sediment analysis and bioassay testing on selected sediments from Oakland Inner Harbor and Alcatraz disposal site, San Francisco, California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Word, J Q; Ward, J A; Woodruff, D L

1990-09-01

The Battelle/Marine Sciences Laboratory (MSL) was contracted by the US Army Corps of Engineers, San Francisco District, to perform bulk sediment analysis and oyster larvae bioassays (elutriate) on sediments from Inner Oakland Harbor, California. Analysis of sediment characteristics by MSL indicated elevated priority pollutants, PAHs, pesticides, metals, organotins, and oil and grease concentrations, when compared to Alcatraz Island Dredged Material Disposal Site sediment concentrations. Larvae of the Pacific oyster, Crassostrea gigas, were exposed to seawater collected from the Alcatraz Island Site water, and a series of controls using water and sediments collected from Sequim Bay, Washington. Exposure of larvae tomore » the Alcatraz seawater and the 50% and 100% elutriate concentrations from each Oakland sediment resulted in low survival and a high proportion of abnormal larvae compared to Sequim Bay control exposures. MSL identified that field sample collection, preservation, and storage protocols used by Port of Oakland contractors were inconsistent with standard accepted practices. 23 refs., 10 figs., 40 tabs.« less

Development of insect resistant maize plants expressing a chitinase gene from the cotton leaf worm, Spodoptera littoralis

PubMed Central

Osman, Gamal H.; Assem, Shireen K.; Alreedy, Rasha M.; El-Ghareeb, Doaa K.; Basry, Mahmoud A.; Rastogi, Anshu; Kalaji, Hazem M.

2015-01-01

Due to the importance of chitinolytic enzymes for insect, nematode and fungal growth, they are receiving attention concerning their development as biopesticides or chemical defense proteins in transgenic plants and as microbial biocontrol agents. Targeting chitin associated with the extracellular matrices or cell wall by insect chitinases may be an effective approach for controlling pest insects and pathogenic fungi. The ability of chitinases to attack and digest chitin in the peritrophic matrix or exoskeleton raises the possibility to use them as insect control method. In this study, an insect chitinase cDNA from cotton leaf worm (Spodoptera littoralis) has been synthesized. Transgenic maize plant system was used to improve its tolerance against insects. Insect chitinase transcripts and proteins were expressed in transgenic maize plants. The functional integrity and expression of chitinase in progenies of the transgenic plants were confirmed by insect bioassays. The bioassays using transgenic corn plants against corn borer (Sesamia cretica) revealed that ~50% of the insects reared on transgenic corn plants died, suggesting that transgenic maize plants have enhanced resistance against S. cretica. PMID:26658494

A Comparative Analysis of Coprologic Diagnostic Methods for Detection of Toxoplama gondii in Cats

PubMed Central

Salant, Harold; Spira, Dan T.; Hamburger, Joseph

2010-01-01

The relative role of transmission of Toxoplasma gondii infection from cats to humans appears to have recently increased in certain areas. Large-scale screening of oocyst shedding in cats cannot rely on microscopy because oocyst identification lacks sensitivity and specificity, or on bioassays, which require test animals and weeks before examination. We compared a sensitive and species-specific coprologic–polymerase chain reaction (copro-PCR) for detection of T. gondii infected cats with microscopy and a bioassay. In experimentally infected cats followed over time, microscopy was positive occasionally, and positive copro-PCR and bioassay results were obtained continuously from days 2 to 24 post-infection. The copro-PCR is at least as sensitive and specific as the bioassay and is capable of detecting infective oocysts during cat infection. Therefore, this procedure can be used as the new gold standard for determining potential cat infectivity. Its technologic advantages over the bioassay make it superior for large-scale screening of cats. PMID:20439968

Bioassay of naturally occurring allelochemicals for phytotoxicity.

PubMed

Leather, G R; Einhellig, F A

1988-10-01

The bioassay has been one of the most widely used tests to demonstrate allelopathic activity. Often, claims that a particular plant species inhibits the growth of another are based entirely on the seed germination response to solvent extracts of the suspected allelopathic plant; few of these tests are of value in demonstrating allelopathy under natural conditions. The veracity of the bioassay for evaluating naturally occurring compounds for phytotoxicity depends upon the physiological and biochemical response capacity of the bioassay organism and the mechanism(s) of action of the allelochemicals. The possibility that more than one allelochemical, acting in concert at very low concentrations, may be responsible for an observed allelopathic effect makes it imperative that bioassays be extremely sensitive to chemical growth perturbation agents. Among the many measures of phytotoxicity of allelochemicals, the inhibition (or stimulation) of seed germination, radicle elongation, and/or seedling growth have been the parameters of choice for most investigations. Few of these assays have been selected with the view towards the possible mechanism of the allelopathic effect.

Comparison of solid-phase bioassays and ecoscores to evaluate the toxicity of contaminated soils.

PubMed

Lors, Christine; Ponge, Jean-François; Martínez Aldaya, Maite; Damidot, Denis

2010-08-01

Five bioassays (inhibition of lettuce germination and growth, earthworm mortality, inhibition of springtail population growth, avoidance by springtails) were compared, using four coke factory soils contaminated by PAHs and trace elements, before and after biotreatment. For each bioassay, several endpoints were combined in an 'ecoscore', a measure of test sensitivity. Ecoscores pooled over all tested bioassays revealed that most organisms were highly sensitive to the concentration of 3-ring PAHs. When four soils were combined, behavioural tests using the springtail Folsomia candida showed higher ecoscores, i.e. they were most sensitive to soil contamination. However, despite overall higher sensitivity of behavioural tests, which could be used for cheap and rapid assessment of soil toxicity, especially at low levels of contamination, some test endpoints were more sensitive than others, and this may differ from a soil to another, pointing to the need for a battery of bioassays when more itemized results are expected. Copyright 2010 Elsevier Ltd. All rights reserved.

Bt Jute Expressing Fused δ-Endotoxin Cry1Ab/Ac for Resistance to Lepidopteran Pests

PubMed Central

Majumder, Shuvobrata; Sarkar, Chirabrata; Saha, Prosanta; Gotyal, Bheemanna S.; Satpathy, Subrata; Datta, Karabi; Datta, Swapan K.

2018-01-01

Jute (Corchorus sp.) is naturally occurring, biodegradable, lignocellulosic-long, silky, golden shiny fiber producing plant that has great demands globally. Paper and textile industries are interested in jute because of the easy availability, non-toxicity and high yield of cellulosic biomass produced per acre in cultivation. Jute is the major and most industrially used bast fiber-producing crop in the world and it needs protection from insect pest infestation that decreases its yield and quality. Single locus integration of the synthetically fused cry1Ab/Ac gene of Bacillus thuringiensis (Bt) in Corchorus capsularis (JRC 321) by Agrobacterium tumefaciens-mediated shoot tip transformation provided 5 potent Bt jute lines BT1, BT2, BT4, BT7 and BT8. These lines consistently expressed the Cry1Ab/Ac endotoxin ranging from 0.16 to 0.35 ng/mg of leaf, in the following generations (analyzed upto T4). The effect of Cry1Ab/Ac endotoxin was studied against 3 major Lepidopteran pests of jute- semilooper (Anomis sabulifera Guenee), hairy caterpillar (Spilarctia obliqua Walker) and indigo caterpillar (Spodoptera exigua Hubner) by detached leaf and whole plant insect bioassay on greenhouse-grown transgenic plants. Results confirm that larvae feeding on transgenic plants had lower food consumption, body size, body weight and dry weight of excreta compared to non-transgenic controls. Insect mortality range among transgenic feeders was 66–100% for semilooper and hairy caterpillar and 87.50% for indigo caterpillar. Apart from insect resistance, the transgenic plants were at par with control plants in terms of agronomic parameters and fiber quality. Hence, these Bt jutes in the field would survive Lepidopteran pest infestation, minimize harmful pesticide usage and yield good quality fiber. PMID:29354143

[Consideration about chemistry, manufacture and control (CMC) key problems in simplified registration of classical traditional Chinese medicine excellent prescriptions].

PubMed

Wang, Zhi-Min; Liu, Ju-Yan; Liu, Xiao-Qian; Wang, De-Qin; Yan, Li-Hua; Zhu, Jin-Jin; Gao, Hui-Min; Li, Chun; Wang, Jin-Yu; Li, Chu-Yuan; Ni, Qing-Chun; Huang, Ji-Sheng; Lin, Juan

2017-05-01

As an outstanding representative of traditional Chinese medicine(TCM) prescriptions accumulated from famous TCM doctors' clinical experiences in past dynasties, classical TCM excellent prescriptions (cTCMeP) are the most valuable part of TCM system. To support the research and development of cTCMeP, a series of regulations and measures were issued to encourage its simplified registration. There is still a long-way to go because many key problems and puzzles about technology, registration and administration in cTCMeP R&D process are not resolved. Based on the analysis of registration and management regulations of botanical drug products in FDA of USA and Japan, and EMA of Europe, the possible key problems and countermeasures in chemistry, manufacture and control (CMC) of simplified registration of cTCMeP were analyzed on the consideration of its actual situation. The method of "reference decoction extract by traditional prescription" (RDETP) was firstly proposed as standard to evaluate the quality and preparation uniformity between the new developing product under simplified registration and traditional original usages of cTCMeP, instead of Standard Decoction method in Japan. "Totality of the evidence" approach, mass balance and bioassay/biological assay of cTCMeP were emphatically suggested to introduce to the quality uniformity evaluation system in the raw drug material, drug substance and final product between the modern product and traditional decoction. Copyright© by the Chinese Pharmaceutical Association.

Biomonitoring of genotoxicity using micronuclei assay in native population of Astyanax jacuhiensis (Characiformes: Characidae) at sites under petrochemical influence.

PubMed

de Lemos, Clarice Torres; Iranço, Fábio de Almeida; de Oliveira, Nânci Cristina D'Avila; de Souza, Getúlio Dornelles; Fachel, Jandyra Maria Guimarães

2008-11-15

Bom Jardim brook is a small stream that flows through an area under the influence of a Petrochemical Complex, demanding control over its quality, so a genotoxic evaluation was performed. This study was conducted in situ, based on previous analysis on the same subject. These were performed both in vitro, with Salmonella typhimurium and human lymphocytes, and in vivo, using bioassays with fish exposed to water from the study area. The purpose of this research was to assess the quality of the aquatic environment and possible effects from petrochemical pollution to surrounding native populations. Micronuclei (MNE) and nuclear abnormalities (NA) frequencies in peripheral blood of Astyanax jacuhiensis, a native fish species collected from the study area, were used as biomarkers. Study period was from summer/99 to spring/2001, using samples obtained seasonally at two ponds upstream from the industrial area (BJN and BJPa) and two sites in Bom Jardim brook (BJ002 and BJ000), which are subject to Complex influence. MNE and NA frequencies found in individuals from BJ002 and BJ000 were similar, showing positive genotoxic responses related to control sites BJN and BJPa. No differential sensitivity could be verified for micronuclei induction between genders of A. jacuhiensis in the studied population. This study showed that sites subject to petrochemical influence were under higher genotoxic impact. Biomarkers adequacy to the case and the sensitivity of A. jacuhiensis for water monitoring could be also inferred.

The effect of changing gravity and weightlessness of vasopressin control systems

NASA Technical Reports Server (NTRS)

Moran, W. H.

1972-01-01

An immunoassay to determine the effects of changing gravity and weightlessness on vasopressin control system is discussed. Seven extracts from persons known to have inappropriate ADH syndrome secondary to pulmonary oat cell cancer were examined. The extracts had previously been subject to bioassay in rats. The intent of the examination was to determine if the vasopressin content could be confirmed immunologically. The results compared favorably with the values obtained by biological assay.

Monitoring the biological activity of micropollutants during advanced wastewater treatment with ozonation and activated carbon filtration.

PubMed

Macova, M; Escher, B I; Reungoat, J; Carswell, S; Chue, K Lee; Keller, J; Mueller, J F

2010-01-01

A bioanalytical test battery was used to monitor the removal efficiency of organic micropollutants during advanced wastewater treatment in the South Caboolture Water Reclamation Plant, Queensland, Australia. This plant treats effluent from a conventional sewage treatment plant for industrial water reuse. The aqueous samples were enriched using solid-phase extraction to separate some organic micropollutants of interest from metals, nutrients and matrix components. The bioassays were chosen to provide information on groups of chemicals with a common mode of toxic action. Therefore they can be considered as sum indicators to detect certain relevant groups of chemicals, not as the most ecologically or human health relevant endpoints. The baseline toxicity was quantified with the bioluminescence inhibition test using the marine bacterium Vibrio fischeri. The specific modes of toxic action that were targeted with five additional bioassays included aspects of estrogenicity, dioxin-like activity, genotoxicity, neurotoxicity, and phytotoxicity. While the accompanying publication discusses the treatment steps in more detail by drawing from the results of chemical analysis as well as the bioanalytical results, here we focus on the applicability and limitations of using bioassays for the purpose of determining the treatment efficacy of advanced water treatment and for water quality assessment in general. Results are reported in toxic equivalent concentrations (TEQ), that is, the concentration of a reference compound required to elicit the same response as the unknown and unidentified mixture of micropollutants actually present. TEQ proved to be useful and easily communicable despite some limitations and uncertainties in their derivation based on the mixture toxicity theory. The results obtained were reproducible, robust and sensitive. The TEQ in the influent ranged in the same order of magnitude as typically seen in effluents of conventional sewage treatment plants. In the initial steps of the treatment chain, no significant degradation of micropollutants was observed, and the high levels of dissolved organic carbon probably affected the outcome of the bioassays. The steps of coagulation/flocculation/dissolved air flotation/sand filtration and ozonation decreased the effect-based micropollutant burden significantly. (c) 2009 Elsevier Ltd. All rights reserved.

Use of bioassays to assess hazard of food contact material extracts: State of the art.

PubMed

Severin, Isabelle; Souton, Emilie; Dahbi, Laurence; Chagnon, Marie Christine

2017-07-01

This review focuses on the use of in vitro bioassays for the hazard assessment of food contact materials (FCM) as a relevant strategy, in complement to analytical methods. FCM may transfer constituents to foods, not always detected by analytical chemistry, resulting in low but measurable human exposures. Testing FCM extracts with bioassays represents the biological response of a combination of substances, able to be released from the finished materials. Furthermore, this approach is particularly useful regarding the current risk assessment challenges with unpredicted/unidentified non-intentionally added substances (NIAS) that can be leached from the FCM in the food. Bioassays applied to assess hazard of different FCM types are described for, to date, the toxicological endpoints able to be expressed at low levels; cytotoxicity, genotoxicity and endocrine disruption potential. The bioassay strengths and relative key points needed to correctly use and improve the performance of bioassays for an additional FCM risk assessment is developed. This review compiles studies showing that combining both chemical and toxicological analyses presents a very promising and pragmatic tool for identifying new undesirable NIAS (not predicted) which can represent a great part of the migrating substances and/or "cocktail effect". Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of subsurface exploration, sampling, and water-quality-analysis methods at an abandoned wood-preserving plant site at Jackson, Tennessee

USGS Publications Warehouse

Parks, W.S.; Carmichael, J.K.; Mirecki, J.E.

1993-01-01

Direct Push Technology (DPT) and a modified-auger method of sampling were used at an abandoned wood-preserving plant site at Jackson, Tennessee, to collect lithologic data and ground-water samples in an area known to be affected by a subsurface creosote plume. The groundwater samples were analyzed using (1) gas chromatography with photo-ionization detection (GS/PID), (2) high- performance liquid chromatography (HPLC), (3) colonmetric phenol analysis, and (4) toxicity bioassay. DPT piezocone and cone-penetrometer-type tools provided lithologic data and ground-water samples at two onsite stations to a depth of refusal of about 35 feet below land surface. With the assistance of an auger rig, this depth was extended to about 65 feet by pushing the tools in advance of the augers. Following the DPT work, a modified-auger method was tested by the USGS. This method left doubt as to the integrity of the samples collected once zones of contamination were penetrated. GC/PID and HPLC methods of water-quality analysis provided the most data concerning contaminants in the ground-water and proved to be the most effective in creosote plume detection. Analyses from these methods showed that the highest concentrations of contaminants were detected at depths less than about 35 feet below land surface. Phenol analyses provided data supplemental to the HPLC analyses. Bioassay data indicated that toxicity associated with the plume extended to depths of about 55 feet below land surface.

Susceptibility profile and metabolic mechanisms involved in Aedes aegypti and Aedes albopictus resistant to DDT and deltamethrin in the Central African Republic.

PubMed

Ngoagouni, Carine; Kamgang, Basile; Brengues, Cécile; Yahouedo, Gildas; Paupy, Christophe; Nakouné, Emmanuel; Kazanji, Mirdad; Chandre, Fabrice

2016-11-24

Aedes aegypti and Ae. albopictus are the main epidemic vectors of dengue, chikungunya and Zika viruses worldwide. Their control during epidemics relies mainly on control of larvae and adults with insecticides. Unfortunately, loss of susceptibility of both species to several insecticide classes limits the efficacy of interventions. In Africa, where Aedes-borne viruses are of growing concern, few data are available on resistance to insecticides. To fill this gap, we assessed the susceptibility to insecticides of Ae. aegypti and Ae. albopictus populations in the Central African Republic (CAR) and studied the mechanisms of resistance. Immature stages were sampled between June and September 2014 in six locations in Bangui (the capital of CAR) for larval and adult bioassays according to WHO standard procedures. We also characterized DDT- and pyrethroid-resistant mosquitoes molecularly and biochemically, including tests for the activities of nonspecific esterases (α and β), mixed-function oxidases, insensitive acetylcholinesterase and glutathione S-transferases. Larval bioassays, carried out to determine the lethal concentrations (LC 50 and LC 95 ) and resistance ratios (RR 50 and RR 95 ), suggested that both vector species were susceptible to Bacillus thuringiensis var. israeliensis and to temephos. Bioassays of adults showed susceptibility to propoxur and fenitrothion, except for one Ae. albopictus population that was suspected to be resistant to fenithrothion. None of the Ae. aegypti populations was fully susceptible to DDT. Ae. albopictus presented a similar profile to Ae. aegypti but with a lower mortality rate (41%). Possible resistance to deltamethrin was observed among Ae. aegypti and Ae. albopictus, although some were susceptible. No kdr mutations were detected in either species; however, the activity of detoxifying enzymes was higher in most populations than in the susceptible Ae. aegypti strain, confirming decreased susceptibility to DDT and deltamethrin. These findings suggested that regular, continuous monitoring of resistance is necessary in order to select the most effective adulticides for arbovirus control in Bangui.

Underpinning Sustainable Vector Control through Informed Insecticide Resistance Management

PubMed Central

Hemmings, Kay; Hughes, Angela J.; Chanda, Emmanuel; Musapa, Mulenga; Kamuliwo, Mulakwa; Phiri, Faustina N.; Muzia, Lucy; Chanda, Javan; Kandyata, Alister; Chirwa, Brian; Poer, Kathleen; Hemingway, Janet; Wondji, Charles S.; Ranson, Hilary; Coleman, Michael

2014-01-01

Background There has been rapid scale-up of malaria vector control in the last ten years. Both of the primary control strategies, long-lasting pyrethroid treated nets and indoor residual spraying, rely on the use of a limited number of insecticides. Insecticide resistance, as measured by bioassay, has rapidly increased in prevalence and has come to the forefront as an issue that needs to be addressed to maintain the sustainability of malaria control and the drive to elimination. Zambia's programme reported high levels of resistance to the insecticides it used in 2010, and, as a result, increased its investment in resistance monitoring to support informed resistance management decisions. Methodology/Principal Findings A country-wide survey on insecticide resistance in Zambian malaria vectors was performed using WHO bioassays to detect resistant phenotypes. Molecular techniques were used to detect target-site mutations and microarray to detect metabolic resistance mechanisms. Anopheles gambiae s.s. was resistant to pyrethroids, DDT and carbamates, with potential organophosphate resistance in one population. The resistant phenotypes were conferred by both target-site and metabolic mechanisms. Anopheles funestus s.s. was largely resistant to pyrethroids and carbamates, with potential resistance to DDT in two locations. The resistant phenotypes were conferred by elevated levels of cytochrome p450s. Conclusions/Significance Currently, the Zambia National Malaria Control Centre is using these results to inform their vector control strategy. The methods employed here can serve as a template to all malaria-endemic countries striving to create a sustainable insecticide resistance management plan. PMID:24932861

Nanomaterial-Based Electrochemical Biosensors and Bioassays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Guodong; Mao, Xun; Gurung, Anant

2010-08-31

This book chapter summarizes the recent advance in nanomaterials for electrochemical biosensors and bioassays. Biofunctionalization of nanomaterials for biosensors fabrication and their biomedical applications are discussed.

Cross-resistance and synergism bioassays suggest multiple mechanisms of pyrethroid resistance in western corn rootworm populations

PubMed Central

Souza, Dariane; Zukoff, Sarah N.; Meinke, Lance J.; Siegfried, Blair D.

2017-01-01

Recently, resistance to the pyrethroid bifenthrin was detected and confirmed in field populations of western corn rootworm, Diabrotica virgifera virgifera LeConte from southwestern areas of Nebraska and Kansas. As a first step to understand potential mechanisms of resistance, the objectives of this study were i) to assess adult mortality at diagnostic concentration-LC99 to the pyrethroids bifenthrin and tefluthrin as well as DDT, ii) estimate adult and larval susceptibility to the same compounds as well as the organophosphate methyl-parathion, and iii) perform synergism experiments with piperonyl butoxide (PBO) (P450 inhibitor) and S,S,S-tributyl-phosphorotrithioate (DEF) (esterase inhibitor) in field populations. Most of the adult field populations exhibiting some level of bifenthrin resistance exhibited significantly lower mortality to both pyrethroids and DDT than susceptible control populations at the estimated LC99 of susceptible populations. Results of adult dose-mortality bioassays also revealed elevated LC50 values for bifenthrin resistant populations compared to the susceptible control population with resistance ratios ranging from 2.5 to 5.5-fold for bifenthrin, 28 to 54.8-fold for tefluthrin, and 16.3 to 33.0 for DDT. These bioassay results collectively suggest some level of cross-resistance between the pyrethroids and DDT. In addition, both PBO and DEF reduced the resistance ratios for resistant populations although there was a higher reduction in susceptibility of adults exposed to PBO versus DEF. Susceptibility in larvae varied among insecticides and did not correlate with adult susceptibility to tefluthrin and DDT, as most resistance ratios were < 5-fold when compared to the susceptible population. These results suggest that both detoxifying enzymes and target site insensitivity might be involved as resistance mechanisms. PMID:28628635

Detection of Reduced Susceptibility to Chlorfenapyr- and Bifenthrin-Containing Products in Field Populations of the Bed Bug (Hemiptera: Cimicidae).

PubMed

Ashbrook, Aaron R; Scharf, Michael E; Bennett, Gary W; Gondhalekar, Ameya D

2017-06-01

Insecticide resistance is a major impediment for effective control of Cimex lectularius L. Previous resistance detection studies with bed bugs have focused on certain pyrethroid, neonicotinoid, organochlorine, organophosphate, and carbamate insecticides. Within the pyrethroid class, resistance studies have mostly been limited to deltamethrin, lambda-cyhalothrin, and alpha- and beta-cyfluthrin. The goal of this study was to develop diagnostic concentration bioassays for assessing bed bug susceptibility levels to chlorfenapyr- and bifenthrin-containing products. First, glass vial and filter paper bioassay methods were compared for their utility in susceptibility monitoring. Statistical comparison of toxicity data between bioassays indicated that the vial assay was less confounded by assay susbtrate effects, required less insecticide, and was faster, especially for chlorfenapyr. Next, using vial diagnostic concentrations (LC99) for each insecticide, 10 laboratory-adapted field strains and the Harlan lab-susceptible strain were screened for susceptibility to chlorfenapyr and bifenthrin. The results of this study reveal recent bed bug susceptibility levels to certain chlorfenapyr- and bifenthrin-containing products. Reduced susceptibility was detected in three and five field strains to chlorfenapyr and bifenthrin, respectively. Detection of reduced susceptibility suggests that certain strains may be segregating toward greater chlorfenapyr and bifenthrin resistance. These results merit continuous resistance monitoring efforts to detect chlorfenapyr and bifenthrin susceptibility shifts. Additionally, to reduce insecticide selection pressures and delay resistance development, adoption of integrated bed bug control strategies that combine chemical and nonchemical methods is recommended. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Molecular and phytochemical investigation of Angelica dahurica and Angelica pubescentis essential oils and their biological activity against Aedes aegypti, Stephanitis pyrioides, and Colletotrichum species.

PubMed

Tabanca, Nurhayat; Gao, Zengping; Demirci, Betul; Techen, Natascha; Wedge, David E; Ali, Abbas; Sampson, Blair J; Werle, Chris; Bernier, Ulrich R; Khan, Ikhlas A; Baser, Kemal Husnu Can

2014-09-03

In this study, Angelica dahurica and Angelica pubescentis root essential oils were investigated as pest management perspectives, and root samples were also analyzed genetically using the nuclear ribosomal internal transcribed spacer (ITS) region as a DNA barcode marker. A. pubescentis root essential oil demonstrated weak antifungal activity against Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides, whereas A. dahurica root essential oil did not show antifungal activity. Conversely, A. dahurica root essential oil demonstrated better biting deterrent and insecticidal activity against yellow fever mosquito, Aedes aegypti, and azalea lace bugs, Stephanitis pyrioides, than A. pubescentis root oil. The major compounds in the A. dahurica oil were found as α-pinene (46.3%), sabinene (9.3%), myrcene (5.5%), 1-dodecanol (5.2%), and terpinen-4-ol (4.9%). α-Pinene (37.6%), p-cymene (11.6%), limonene (8.7%), and cryptone (6.7%) were the major compounds found in the A. pubescentis oil. In mosquito bioassays, 1-dodecanol and 1-tridecanol showed antibiting deterrent activity similar to the positive control DEET (N,N-diethyl-3-methylbenzamide) at 25 nmol/cm(2) against Ae. aegypti, whereas only 1-tridecanol showed repellent activity in human-based cloth patch bioassay with minimum effective dosages (MED) of 0.086 ± 0.089 mg/cm(2) (DEET = 0.007 ± 0.003 mg/cm(2)). In larval bioassays, 1-tridecanol was more toxic with an LC50 value of 2.1 ppm than 1-dodecanol having an LC50 value of 5.2 ppm against 1-day-old Ae. aegypti larvae. 1-Dodecanol and 1-tridecanol could be useful for the natural mosquito control agents.

Disrupting Mating Behavior of Diaphorina citri (Liviidae).

PubMed

Lujo, S; Hartman, E; Norton, K; Pregmon, E A; Rohde, B B; Mankin, R W

2016-12-01

Severe economic damage from citrus greening disease, caused by 'Candidatus Liberibacter asiaticus' bacteria, has stimulated development of methods to reduce mating and reproduction in populations of its insect vector, Diaphorina citri (Hemiptera: Liviidae). Male D. citri find mating partners by walking on host plants, intermittently producing vibrational calls that stimulate duetting replies by receptive females. The replies provide orientational feedback, assisting the search process. To test a hypothesis that D. citri mating can be disrupted using vibrational signals that compete with and/or mask female replies, courtship bioassays were conducted in citrus trees with or without interference from female reply mimics produced by a vibrating buzzer. Statistically significant reductions occurred in the rates and proportions of mating when the buzzer produced reply mimics within 0.4 s after male courtship calls compared with undisturbed controls. Observations of courtship behaviors in the two bioassays revealed activity patterns that likely contributed to the reductions. In both disruption and control tests, males reciprocated frequently between structural bifurcations and other transition points where signal amplitudes changed. Males in the disruption bioassay had to select among vibrational signals combined from the buzzer and the female at each transition point. They often turned towards the buzzer instead of the female. There was a statistically significant reduction in the proportion of males mating if they contacted the buzzer, possibly due to its higher vibration amplitude and duration in comparison with female replies. Potential applications of D. citri mating disruption technology in citrus groves are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2016. This work is written by US Government employees and is in the public domain in the US.

A fixed-dose approach to conducting emamectin benzoate tolerance assessments on field-collected sea lice, Lepeophtheirus salmonis.

PubMed

Whyte, S K; Westcott, J D; Elmoslemany, A; Hammell, K L; Revie, C W

2013-03-01

In New Brunswick, Canada, the sea louse, Lepeophtheirus salmonis, poses an on-going management challenge to the health and productivity of commercially cultured Atlantic salmon, Salmo salar. While the in-feed medication, emamectin benzoate (SLICE® ; Merck), has been highly effective for many years, evidence of increased tolerance has been observed in the field since late 2008. Although bioassays on motile stages are a common tool to monitor sea lice sensitivity to emamectin benzoate in field-collected sea lice, they require the collection of large numbers of sea lice due to inherent natural variability in the gender and stage response to chemotherapeutants. In addition, sensitive instruments such as EC(50) analysis may be unnecessarily complex to characterize susceptibility subsequent to a significant observed decline in efficacy. This study proposes an adaptation of the traditional, dose-response format bioassay to a fixed-dose method. Analysis of 657 bioassays on preadult and adult stages of sea lice over the period 2008-2011 indicated a population of sea lice in New Brunswick with varying degrees of susceptibility to emamectin benzoate. A seasonal and spatial effect was observed in the robustness of genders and stages of sea lice, which suggest that mixing different genders and stages of lice within a single bioassay may result in pertinent information being overlooked. Poor survival of adult female lice in bioassays, particularly during May/June, indicates it may be prudent to consider excluding this stage from bioassays conducted at certain times of the year. This work demonstrates that fixed-dose bioassays can be a valuable technique in detecting reduced sensitivity in sea lice populations with varying degrees of susceptibility to emamectin benzoate treatments. © 2013 Blackwell Publishing Ltd.

Genotoxicity of soil from farmland irrigated with wastewater using three plant bioassays.

PubMed

Cabrera, G L; Rodriguez, D M

1999-05-19

Three well known plant bioassays, the Allium root chromosome aberration (AL-RAA) assay, the Tradescantia micronucleus (Trad-MCN) assay, and the Tradescantia stamen hair (Trad-SHM) mutation assay were validated in 1991 by the International Programme on Chemical Safety (IPCS) under the auspices of the World Health Organization, and the United Nations Environment Programme (UNEP). These plant bioassays have proven to be efficient tests for chemical screening and especially for in situ monitoring for genotoxicity of environmental pollutants. As a result of this validation study, standard protocols of these three plant bioassays were used by some of the 11 participating countries in the IPCS to carry on genotoxicity tests on air, water and soil as a follow up activity. In the city of Queretaro, Mexico, wastewater coming from both industrial and domestic sources and without any treatment is used to irrigate the farm crops, polluting the soil. Potentially the pollutants could reach the food chain. For the above reason, soil irrigated with wastewater was sampled and monitored for the presence of genotoxic agents using the above three bioassays. Extracts from soil samples were made using distilled water and organic solvents by shaking the sample for about 12 h under a relatively low temperature (15-20 degrees C). Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the extracts. Three replicates of each sample were analyzed in each of the three bioassays. Extracts using DMSO, ethanol and distilled water tested positive in the three bioassays and there were no differences for the genotoxicity of the extracts with the different solvents. Copyright 1999 Elsevier Science B.V.

Molecular and functional characterization of cry1Ac transgenic pea lines.

PubMed

Teressa Negawo, Alemayehu; Baranek, Linda; Jacobsen, Hans-Jörg; Hassan, Fathi

2016-10-01

Transgenic pea lines transformed with the cry1Ac gene were characterized at molecular (PCR, RT-PCR, qRT-PCR and immunostrip assay) and functional levels (leaf paint and insect feeding bioassays). The results showed the presence, expression, inheritance and functionality of the introduced transgene at different progeny levels. Variation in the expression of the cry1Ac gene was observed among the different transgenic lines. In the insect bioassay studies using the larvae of Heliothis virescens, both larval survival and plant damage were highly affected on the different transgenic plants. Up to 100 % larval mortality was observed on the transgenic plants compared to 17.42 % on control plants. Most of the challenged transgenic plants showed very negligible to substantially reduced feeding damage indicating the insect resistance of the developed transgenic lines. Further analysis under field condition will be required to select promising lines for future uses.

Molecular and functional characterization of cry1Ac transgenic pea lines

PubMed Central

Teressa Negawo, Alemayehu; Baranek, Linda; Jacobsen, Hans-Jörg; Hassan, Fathi

2016-01-01

ABSTRACT Transgenic pea lines transformed with the cry1Ac gene were characterized at molecular (PCR, RT-PCR, qRT-PCR and immunostrip assay) and functional levels (leaf paint and insect feeding bioassays). The results showed the presence, expression, inheritance and functionality of the introduced transgene at different progeny levels. Variation in the expression of the cry1Ac gene was observed among the different transgenic lines. In the insect bioassay studies using the larvae of Heliothis virescens, both larval survival and plant damage were highly affected on the different transgenic plants. Up to 100 % larval mortality was observed on the transgenic plants compared to 17.42 % on control plants. Most of the challenged transgenic plants showed very negligible to substantially reduced feeding damage indicating the insect resistance of the developed transgenic lines. Further analysis under field condition will be required to select promising lines for future uses. PMID:27764552

Rapid, Bioassay-Guided Process for the Detection and Identification of Antibacterial Neem Oil Compounds.

PubMed

Krüzselyi, Dániel; Nagy, Róbert; Ott, Péter G; Móricz, Ágnes M

2016-08-01

Bioassay guidance was used along the whole process including method development, isolation and identification of antibacterial neem (Azadirachta indica) oil compounds. The biomonitoring was performed by direct bioautography (DB), a combination of thin-layer chromatography (TLC) and antimicrobial detection. DB of neem oil showed one antibacterial zone that was not UV-active; therefore, the TLC separation was improved under DB control. The chromatographic zone that exhibited activity against Bacillus subtilis, Xanthomonas euvesicatoria, Aliivibrio fischeri, Staphylococcus aureus and methicillin-resistant Staphylococcus aureus was characterized by TLC reagents, indicating a lipophilic, fatty acid-like chemical feature. Two compounds were found and identified in the active zone by high-performance liquid chromatography-electrospray ionization mass spectrometry as linoleic and oleic acids. Both fatty acids inhibited B. subtilis, but A. fischeri was sensitive only against linoleic acid. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Amphipod bioassay of selected sediments from Sequim Bay, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsdell, K.A.; Strand, J.A.; Cullinan, V. I.

1989-06-01

Amphipod bioassays performed during reconnaissance surveys of Sequim Bay in 1983--1984 for the US Environmental Protection Agency suggested possible sediment toxicity at three sites. These findings were not supported by other biological analyses and tests (dominant infauna, oyster larvae test) nor by the finding of relatively low levels of priority pollutants. In 1988, a re-examination of the 1983--1984 sites demonstrated that the Sequim Bay sediments were clearly nontoxic. Mean survivorship ranged from 89 to 100%. It was hypothesized that earlier indications of toxicity may have been due to a relatively high percentage of fines ({ge}80%) and/or a relatively low interstitialmore » salinity (24%) encountered at one or more of the 1983--1984 sites. The continued use of Sequim Bay as both a reference bay and a source of control sediment in future marine research is recommended. 13 refs., 5 figs., 3 tabs.« less

Effect of soil properties on the toxicity of Pb: assessment of the appropriateness of guideline values.

PubMed

Romero-Freire, A; Martin Peinado, F J; van Gestel, C A M

2015-05-30

Soil contamination with lead is a worldwide problem. Pb can cause adverse effects, but its mobility and availability in the terrestrial environment are strongly controlled by soil properties. The present study investigated the influence of different soil properties on the solubility of lead in laboratory spiked soils, and its toxicity in three bioassays, including Lactuca sativa root elongation and Vibrio fischeri illumination tests applied to aqueous extracts and basal soil respiration assays. Final aim was to compare soil-dependent toxicity with guideline values. The L. sativa bioassay proved to be more sensitive to Pb toxicity than the V. fischeri and soil respiration tests. Toxicity was significantly correlated with soil properties, with soil pH, carbonate and organic carbon content being the most important factors. Therefore, these variables should be considered when defining guideline values. Copyright © 2015 Elsevier B.V. All rights reserved.

Immunostimulation of Salmo salar L., and its effect on Lepeophtheirus salmonis (Krøyer) P-glycoprotein mRNA expression following subsequent emamectin benzoate exposure.

PubMed

Igboeli, O O; Purcell, S L; Wotton, H; Poley, J; Burka, J F; Fast, M D

2013-03-01

Control of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar, relies heavily on chemotherapeutants. However, reduced efficacy of many treatments and need for integrated sea lice management plans require innovative strategies. Resistance to emamectin benzoate (EMB), a major sea lice parasiticide, has been linked with P-glycoprotein (P-gp) expression. We hypothesized that host immunostimulation would complement EMB treatment outcome. Lepeophtheirus salmonis-infected Atlantic salmon were fed immunostimulatory or control feeds. Sea lice were collected for 24-h EMB bioassays 1 and 2 weeks prior to commencement of EMB treatment of the fish. Two weeks after cessation of immunostimulant-treated feed, EMB was administered at 150 μg kg(-1) fish biomass for 7 days. The bioassay revealed stage, gender and immunostimulant-related differences in EMB EC(50) . Sea lice attached to salmon with a history of immunostimulation exhibited significantly greater survival than those on control feeds, despite similar levels of EMB in host tissues. Lepeophtheirus salmonis from salmon with a history of immunostimulation also exhibited higher P-gp mRNA expression as well as greater survivability compared to controls. Administration of immunostimulants prior to EMB treatment caused increased expression of P-gp mRNA which could have consequently caused decreased efficacy of the parasiticide. © 2013 Blackwell Publishing Ltd.

Application of Bioassays for the Ecotoxicity Assessment of Contaminated Soils

NASA Astrophysics Data System (ADS)

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 chemical-activated luciferase gene expression bioassay and gas chromatography for PCB determination in human serum and follicular fluid.

PubMed Central

Pauwels, A; Cenijn, P H; Schepens, P J; Brouwer, A

2000-01-01

We assessed exposure to dioxin-like compounds using chemical and bioassay analysis in different matrices in a female population. A total of 106 serum and 9 follicular fluid samples were collected from infertile women attending Centers for Reproductive Medicine in Belgium from 1996 to 1998. Major polychlorinated biphenyl (PCB) congeners were quantified by chemical analysis using gas chromatography with electron-capture detection, and the chemical-activated luciferase gene expression (CALUX) bioassay was used to determine the total dioxin-like toxic equivalence (TEQ) of mixtures of polyhalogenated aromatic hydrocarbons present in body fluids, such as serum and follicular fluid. To the best of our knowledge, this is the first investigation to determine TEQ values by the CALUX bioassay in follicular fluid. The TEQ levels in both matrices are well correlated (r = 0.83, p = 0.02). As the chemical and bioassay analysis executed in this study do not cover the same span of polyhalogenated aromatic hydrocarbons, we did not expect totally correlated results. Moreover, the sample workup and quantification of the analytes differed completely. Nonetheless, the TEQ values in human extracts correlated well with the sum of four major PCB congeners chemically determined in both serum and follicular fluid. These results indicate that the CALUX bioassay may serve as a simple, relatively inexpensive prescreening tool for exposure assessment in epidemiologic surveys. Images Figure 1 Figure 2 PMID:10856030

Adaptation of in vitro bioassays for the diagnosis of resistance to Fipronil and Ivermectin in R. (B.) microplus

USDA-ARS?s Scientific Manuscript database

R. microplus represents the most important pathological constraint to livestock production in Brazil and Uruguay. The infestation of cattle by ticks is controlled by chemical applications on a regular basis. Fipronil and ivermectin have been widely used in recent years to the benefit of cattle produ...

Glyphosate toxicity and the effects of long-term vegetation control on soil microbial communities

Treesearch

Matt D. Busse; Alice W. Ratcliff; Carol J. Stestak; Robert F. Powers

2001-01-01

We assessed the direct and indirect effect of the herbicide glyphosate on soil microbial communities from soil bioassays at glyphosate concentrations up to 100-fold greater than expected following a single field application. Indirect effects on microbial biomass, respiration, and metabolic diversity (Biolog and catabolic response profile) were compared seasonally after...

Aerial application of Agri-Fos® to prevent Sudden Oak Death in Oregon tanoak forests

Treesearch

Alan Kanaskie; Everett Hansen; Wendy Sutton; Paul Reeser; Carolyn Choquette

2010-01-01

We have been testing the practicality and efficacy of aerial application of Agri-Fos® for control of sudden oak death (SOD) in the Oregon tanoak (Lithocarpus densiflorus) forest. Helicopter application to forest stands has been compared with bole injection and groundbased spray application to seedlings and stump sprouts. We bio-assayed...

Comparative analysis of pesticide effects on natural enemies in western orchards: a synthesis of laboratory bioassay data

USDA-ARS?s Scientific Manuscript database

Pesticides are commonly used for management of codling moth and diseases in apple, pear and walnut orchards in the western U.S. and these pesticides may disrupt the biological control of secondary pests in these crops. A comparative analysis was made of results obtained from a series of studies of ...

Susceptibility of larvae of nun moth, Lymantria monacha (Linnaeus 1758) (Lepidoptera), to the entomopathogenic fungus, Entomophaga maimaiga Humber, Shimazu and Soper (Entomophthorales) under laboratory and field conditions

Treesearch

Daniela Pilarska; Ann E. Hajek; Melody Keena; Andreas Linde; Manana Kereselidze; Georgi Georgiev; Margarita Georgieva; Plamen Mirchev; Danail Takov; Slavimira Draganova

2016-01-01

Susceptibility of Lymantria monacha larvae to Entomophaga maimaiga was investigated under laboratory and field conditions, using larvae of the natural host, Lymantria dispar, as positive controls. In laboratory bioassays, L. monacha and L. dispar were injected with...

Residual efficacy of pyrethrin+methoprene for control of Tribolium castaneum and Tribolium confusum in a commercial flour mill

USDA-ARS?s Scientific Manuscript database

Concrete arenas with and without flour were placed in open, obstructed, and hidden positions inside a commercial flour mill and exposed to a combination treatment of pyrethrin + methoprene. Bioassays were conducted 1, 3, 5, and 7 weeks after the arenas were treated by adding flour to those arenas th...

Residual efficacy of methoprene for control of Tribolium castaneum (Coleoptera: Tenebrionidae) larvae at different temperatures on varnished wood, concrete, and wheat

USDA-ARS?s Scientific Manuscript database

The residual efficacy of the juvenile hormone analogue, methoprene (Diacon II), was evaluated in bioassays using larvae of Tribolium castaneum (Herbst) exposed on varnished wood or unsealed concrete treated with a liquid formulation and held at different temperatures. When these surfaces were stored...

Toxicity to adult brown stink bug (Hemiptera: Pentatomidae) in a glass-vial bioassay of selected insecticide mixture

USDA-ARS?s Scientific Manuscript database

The brown stink bug (BSB), Euschistus servus (Say) has become the predominant species among the stink bug complex on cotton in Central Texas. Control options to suppress the insect are largely dependent upon and limited to the use of insecticides. Data are needed to determine the toxicity of current...

Utilization of a duckweed bioassay to evaluate leaching of heavy metals in smelter contaminated soils

DOE Office of Scientific and Technical Information (OSTI.GOV)

Youngman, A.L.; Lydy, M.J.; Williams, T.L.

1998-12-31

The purpose of this study was to determine whether a duckweed bioassay could be used to evaluate the downward migration of heavy metals in smelter soils. The duckweed bioassay was initially used to evaluate elutriates prepared from samples of smelter soils. These initial tests verified that the elutriates would elicit toxic responses. Elutriate testing was followed with an evaluation of leachate from untreated soil cores or soil cores that had been amended with organic matter either unplanted or planted to a grass-forb seed mixture. There was an inverse linear relationship between heavy-metal concentrations in leachate and NOEC and IC{sub 50}more » values expressed as percentages among all soil cores. Based on these preliminary duckweed bioassays, there were no differences between soil types or organic amended or non-amended soil, but leachate from vegetated soil cores were less toxic than were leachates from non-vegetated soil cores. Overall, the duckweed bioassays were useful in detecting heavy metal availability in elutriate and leachate samples from smelter soils.« less

Assessment of the genotoxicity of 137Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays.

PubMed

Minouflet, Marion; Ayrault, Sophie; Badot, Pierre-Marie; Cotelle, Sylvie; Ferard, Jean-François

2005-01-01

Since the middle of the 20th century, ionizing radiations from radioactive isotopes including 137Cs have been investigated to determine their genotoxic impact on living organisms. The present study was designed to compare the effectiveness of three plant bioassays to assess DNA damage induced by low doses of 137Cs: Vicia-micronucleus test (Vicia-MCN), Tradescantia-micronucleus test (Trad-MCN) and Tradescantia-stamen-hair mutation test (Trad-SH) were used. Vicia faba (broad bean) and Tradescantia clone 4430 (spiderwort) were exposed to 137Cs according to different scenarios: external and internal (contamination) irradiations. Experiments were conducted with various levels of radioactivity in solution or in soil, using solid or liquid 137Cs sources. The three bioassays showed different sensitivities to the treatments. Trad-MCN appeared to be the most sensitive test (significative response from 1.5 kBq/200 ml after 30 h of contamination). Moreover, at comparable doses, internal irradiations led to larger effects for the three bioassays. These bioassays are effective tests for assessing the genotoxic effects of radioactive 137Cs pollution.

Environmental legislation and aquatic ecotoxicology in Mexico: past, present and future scenarios.

PubMed

Mendoza-Cantú, Ania; Ramírez-Romero, Patricia; Pica-Granados, Yolanda

2007-08-01

The consolidation of environmental legislation is fundamental for governments that wish to support and promote different actions focused on reducing pollution and protecting natural water resources in order to maintain the present and future benefits that water provides for human beings and wild life. Environmental laws are essential for sustaining human activities and health, preserving biodiversity and promoting sustainable development. In this context, it is important that environmental regulations concentrate on preventing or reducing the harmful impact of pollutants on organisms and ecosystems. The introduction of toxicity bioassays in environmental regulations is a positive step toward achieving this goal. In Mexico, the development of environmental legislation and the introduction of bioassays in water regulation are part of a very recent and complex journey. This article describes how aquatic ecotoxicology tools, particularly bioassays, have influenced water pollution policies in Mexico. Three scenarios are reviewed: the background of Mexican legislation on water protection and Mexico's participation in the Watertox project; the actual efforts of SEMARNAT to develop bioassay batteries for this country; and, the challenges and perspectives of ecotoxicological bioassays as regulatory instruments.

Effects of Water Quality on Survival and Reproduction of Four Species of Planaria (Turbellaria: Tricladida)

DTIC Science & Technology

1994-01-01

Institute of Research, Washington, DC 20307-5100, USA Received 4 June 1992; Accepted 15 September 1993 Summary In a series of bioassays, four planarian ...Marking All previous research on the physical and chemical and Dawson, 1973) for four water hardness levels of effects on planarian growth and...reproduction has been very soft (10-13mg/I CaCO 3), soft (40-48mg/1 designed to study development of planarian mass CaCO3), hard (160-168 mg/l CaCO 3), and very

Assessing sediment hazard through a weight of evidence approach with bioindicator organisms: a practical model to elaborate data from sediment chemistry, bioavailability, biomarkers and ecotoxicological bioassays.

PubMed

Piva, Francesco; Ciaprini, Francesco; Onorati, Fulvio; Benedetti, Maura; Fattorini, Daniele; Ausili, Antonella; Regoli, Francesco

2011-04-01

Quality assessments are crucial to all activities related to removal and management of sediments. Following a multidisciplinary, weight of evidence approach, a new model is presented here for comprehensive assessment of hazards associated to polluted sediments. The lines of evidence considered were sediment chemistry, assessment of bioavailability, sub-lethal effects on biomarkers, and ecotoxicological bioassays. A conceptual and software-assisted model was developed with logical flow-charts elaborating results from each line of evidence on the basis of several chemical and biological parameters, normative guidelines or scientific evidence; the data are thus summarized into four specific synthetic indices, before their integration into an overall sediment hazard evaluation. This model was validated using European eels (Anguilla anguilla) as the bioindicator species, exposed under laboratory conditions to sediments from an industrial site, and caged under field conditions in two harbour areas. The concentrations of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and trace metals were much higher in the industrial compared to harbour sediments, and accordingly the bioaccumulation in liver and gills of exposed eels showed marked differences between conditions seen. Among biomarkers, significant variations were observed for cytochrome P450-related responses, oxidative stress biomarkers, lysosomal stability and genotoxic effects; the overall elaboration of these data, as those of standard ecotoxicological bioassays with bacteria, algae and copepods, confirmed a higher level of biological hazard for industrial sediments. Based on comparisons with expert judgment, the model presented efficiently discriminates between the various conditions, both as individual modules and as an integrated final evaluation, and it appears to be a powerful tool to support more complex processes of environmental risk assessment. Copyright © 2010 Elsevier Ltd. All rights reserved.

Chapter A7. Biological Indicators

USGS Publications Warehouse

Myers, Donna N.; Wilde, Franceska D.

2003-01-01

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual includes procedures for the (1) determination of biochemical oxygen demand using a 5-day bioassay test; (2) collection, identification, and enumeration of fecal indicator bacteria; (3) collection of samples and information on two laboratory methods for fecal indicator viruses (coliphages); and (4) collection of samples for protozoan pathogens. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters are posted on the World Wide Web on the USGS page 'National Field Manual for the Collection of Water-Quality Data.' The URL for this page is http://pubs.water.usgs.gov/twri9A/ (accessed November 25, 2003).

Carbon-14 bioassay for decommissioning of Hanford reactors.

PubMed

Carbaugh, Eugene H; Watson, David J

2012-05-01

The production reactors at the U.S. Department of Energy Hanford Site used large graphite piles as the moderator. As part of long-term decommissioning plans, the potential need for ¹⁴C radiobioassay of workers was identified. Technical issues associated with ¹⁴C bioassay and worker monitoring were investigated, including anticipated graphite characterization, potential intake scenarios, and the bioassay capabilities that may be required to support the decommissioning of the graphite piles. A combination of urine and feces sampling would likely be required for the absorption type S ¹⁴C anticipated to be encountered. However, the concentrations in the graphite piles appear to be sufficiently low that dosimetrically significant intakes of ¹⁴C are not credible, thus rendering moot the need for such bioassay.

The effect of pesticide residue on caged mosquito bioassays.

PubMed

Barber, J A S; Greer, Mike; Coughlin, Jamie

2006-09-01

Wind tunnel experiments showed that secondary pickup of insecticide residue by mosquitoes in cage bioassays had a significant effect on mortality. Cage bioassays using adult Ochlerotatus taeniorhynchus (Wiedemann) investigated the effect of exposure time to a contaminated surface. Cages were dosed in a wind tunnel using the LC50 for naled (0.124 mg a.i./ml) and an LC25 (0.0772 mg a.i./ml) for naled. Half of the bioassay mosquitoes were moved directly into clean cages with the other half remaining in the sprayed, hence contaminated, cage. Treatment mortality was assessed at 8, 15, 30, 60, 120, 240, and 1,440 min postapplication. Cage contamination had a significant effect on mosquito mortality for both the LC25 and LC50 between 15 and 30 min postapplication.

Carbon-14 Bioassay for Decommissioning of Hanford Reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Watson, David J.

2012-05-01

The old production reactors at the US Department of Energy Hanford Site used large graphite piles as the moderator. As part of long-term decommissioning plans, the potential need for 14C radiobioassay of workers was identified. Technical issues associated with 14C bioassay and worker monitoring were investigated, including anticipated graphite characterization, potential intake scenarios, and the bioassay capabilities that may be required to support the decommissioning of the graphite piles. A combination of urine and feces sampling would likely be required for the absorption type S 14C anticipated to be encountered. However the concentrations in the graphite piles appear to bemore » sufficiently low that dosimetrically significant intakes of 14C are not credible, thus rendering moot the need for such bioassay.« less

Evaluation of barrier treatments on native vegetation in a southern California desert habitat.

PubMed

Britch, Seth C; Linthicum, Kenneth J; Wynn, Wayne W; Walker, Todd W; Farooq, Muhammad; Smith, Vincent L; Robinson, Cathy A; Lothrop, Branka B; Snelling, Melissa; Gutierrez, Arturo; Lothrop, Hugh D

2009-06-01

Treating perimeters with residual insecticides for protection from mosquito vectors has shown promise. These barrier treatments are typically evaluated in temperate or tropical areas using abundant vegetation as a substrate. However, there is an emerging interest to develop this technology to protect deployed US troops in extreme desert environments with sparse vegetation. We used a remote desert area in the Coachella Valley, California, to 1) evaluate bifenthrin barrier treatments on native xeric vegetation and 2) compare treatments applied with electrostatic and conventional spray technologies. Through a combination of laboratory bioassays on treated and control vegetation sampled at specific intervals over 63 days, synchronized with field surveillance of mosquitoes, we measured the temporal pattern of bioactivity of bifenthrin barriers under natural hot, dry, and dusty desert conditions. Regardless of spray technology, mosquito catch in treated plots was about 80% lower than the catch in control plots 1 day after treatment. This reduction in mosquito numbers in treated plots declined each week after treatment but remained at about 40% lower than control plots after 28 days. Field data were corroborated by results from bioassays that showed significantly higher mosquito mortality on treated vegetation over controls out to 28 days postspray. We concluded that barrier treatments in desert environments, when implemented as part of a suite of integrated control measures, may offer a significant level of protection from mosquitoes for deployed troops. Given the comparable performance of the tested spray technologies, we discuss considerations for choosing a barrier treatment sprayer for military scenarios.

Evaluation of alternative rice planthopper control by the combined action of oil-formulated Metarhizium anisopliae and low-rate buprofezin.

PubMed

Jin, Shao-Feng; Feng, Ming-Guang; Ying, Sheng-Hua; Mu, Wen-Jing; Chen, Jue-Qi

2011-01-01

High resistance of brown planthopper (BPH) Nilaparvata lugens Stål to common insecticides is a challenge for control of the pest. An alternative control strategy based on the combined application of fungal and chemical agents has been evaluated. Three gradient spore concentrations of oil-formulated Metarhizium anisopliae (Metschnikoff) Sorokin (Ma456) were sprayed onto third-instar nymphs in five bioassays comprising the low buprofezin rates of 0, 10, 20, 30 and 40 µg mL(-1) respectively. Fungal LC(50) after 1 week at 25 °C and 14:10 h light:dark photoperiod decreased from 386 conidia mm(-2) in the buprofezin-free bioassay to 40 at the highest chemical rate. Buprofezin (LC(50): 1647, 486 and 233 µg mL(-1) on days 2 to 4) had no significant effect on the fungal outgrowths of mycosis-killed cadavers at the low application rates. The fungal infection was found to cause 81% reduction in reproductive potential of BPH adults. In two 40 day field trials, significant planthopper (mainly BPH) control (54-60%) was achieved by biweekly sprays of two fungal candidates (Ma456 and Ma576) at 1.5 × 10(13) conidia ha(-1) and elevated to 80-83% by incorporating 30.8 g buprofezin ha(-1) into the fungal sprays. The combined application of the fungal and chemical agents is a promising alternative strategy for BPH control. Copyright © 2010 Society of Chemical Industry.

Rat medium-term multi-organ carcinogenesis bioassay of Agaricus blazei Murrill fruit-body extract.

PubMed

Doi, Yuko; Furukawa, Fumio; Suguro, Mayuko; Ito, Hikaru; Imai, Norio; Nabae, Kyoko; Toda, Yosuke; Inatomi, Satoshi; Kinugasa, Satomi; Kobayashi, Hitoshi

2010-01-01

The modifying potential of Agaricus blazei Murrill fruit-body extract (ABFE) on tumor development was investigated in a medium-term multi-organ carcinogenesis bioassay. Male 6-week-old F344 rats were treated with N-nitrosodiethylamine (DEN), N-methyl-N-nitrosourea (MNU), 1,2-dimethylhydrazine dihydrochloride (DMH), N-butyl-N-(hydroxybutyl)-nitrosamine (BBN), and diisopropanolnitrosamine (DHPN) for initiation (DMBDD treatment). After a 1-week withdrawal period, the animals received distilled water (vehicle control) or ABFE A, gamma-amino butyric acid (GABA) at 0.8 mg/kg, ABFE B (GABA level of 3.0mg/kg) or ABFE C (GABA level of 12.0mg/kg) by gavage for 24 weeks. There were no effects of ABFE on survival rate, general condition, body weight, food and water consumption, and organ weights. The multiplicity of large intestinal nodules, smaller than 2mm was significantly increased in the ABFE C group with DMBDD treatment. However, there were no significantly inter-group differences in incidences of hyperplastic or neoplastic lesions in colon or other organs, or in immunohistochemically identified preneoplastic lesions in the liver. In conclusion, A. blazei Murrill fruit-body extract, even at a GABA level up to 12 mg/kg, did not exert modifying potential in the present medium-term multi-organ carcinogenesis bioassay in male F344 rats (DMBDD method). Copyright 2009 Elsevier Ltd. All rights reserved.

A magnetic nanobead-based bioassay provides sensitive detection of single- and biplex bacterial DNA using a portable AC susceptometer

PubMed Central

Strömberg, Mattias; Zardán Gómez de la Torre, Teresa; Nilsson, Mats; Svedlindh, Peter; Strømme, Maria

2014-01-01

Bioassays relying on magnetic read-out using probe-tagged magnetic nanobeads are potential platforms for low-cost biodiagnostic devices for pathogen detection. For optimal assay performance it is crucial to apply an easy, efficient and robust bead-probe conjugation protocol. In this paper, sensitive (1.5 pM) singleplex detection of bacterial DNA sequences is demonstrated in a portable AC susceptometer by a magnetic nanobead-based bioassay principle; the volume-amplified magnetic nanobead detection assay (VAM-NDA). Two bead sizes, 100 and 250 nm, are investigated along with a highly efficient, rapid, robust, and stable conjugation chemistry relying on the avidin–biotin interaction for bead-probe attachment. Avidin-biotin conjugation gives easy control of the number of detection probes per bead; thus allowing for systematic investigation of the impact of varying the detection probe surface coverage upon bead immobilization in rolling circle amplified DNA-coils. The existence of an optimal surface coverage is discussed. Biplex VAM-NDA detection is for the first time demonstrated in the susceptometer: Semi-quantitative results are obtained and it is concluded that the concentration of DNA-coils in the incubation volume is of crucial importance for target quantification. The present findings bring the development of commercial biodiagnostic devices relying on the VAM–NDA further towards implementation in point-of-care and outpatient settings. PMID:24174315

Use of a modified microplate bioassay method to investigate antibacterial activity in the Peruvian medicinal plant Peperomia galioides.

PubMed

Langfield, Richard D; Scarano, Frank J; Heitzman, Mary E; Kondo, Miwako; Hammond, Gerald B; Neto, Catherine C

2004-10-01

A versatile microplate bioassay for quick and sensitive determination of antibacterial activity was developed for use in screening medicinal plants and identification of their active principles. This assay can be used to determine minimum inhibitory concentrations for small quantities of organic or water-soluble plant extracts. Bioassay-guided fractionation of the stem and leaves of Peperomia galioides using this method found fractions containing grifolin and grifolic acid, which inhibited growth of Staphylococcus aureus and Staphylococcus epidermidis.

Aspartame and Risk of Cancer: A Meta-analytic Review.

PubMed

Mallikarjun, Sreekanth; Sieburth, Rebecca McNeill

2015-01-01

Aspartame (APM) is the most commonly used artificial sweetener and flavor enhancer in the world. There is a rise in concern that APM is carcinogenic due to a variation in the findings of the previous APM carcinogenic bioassays. This article conducts a meta-analytic review of all previous APM carcinogenic bioassays on rodents that were conducted before 31 December 2012. The search yielded 10 original APM carcinogenic bioassays on rodents. The aggregate effect sizes suggest that APM consumption has no significant carcinogenic effect in rodents.

Hanford Internal Dosimetry Program Manual, PNL-MA-552

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

2003-10-10

This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP). It describes the roles of and relationships between the IDP and site contractors, and provides recommendations and guidance for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs. Guidance includes identifying conditions under which workers should be placed on bioassay programs, types, descritptions, and capabilities of measurements, suggested routine bioassay programs, limitations on services, and practices for recording and reporting results.

Genotoxicity testing on the international space station: Preparatory work on the SOS-LUX test as part of the space experiment TRIPLE-LUX

NASA Astrophysics Data System (ADS)

Stojicic, Nevena; Walrafen, David; Baumstark-Khan, Christa; Rabbow, Elke; Rettberg, Petra; Weisshaar, Maria-Paz; Horneck, Gerda

Harmful environmental factors - namely ionizing radiation - will continue to influence future manned space missions. The Radiation Biology Unit at the German Aerospace Center (DLR) develops cellular monitoring systems, which include bacterial and mammalian cell systems capable of recognizing DNA damage as a consequence of the presence of genotoxic conditions. Such a bioassay is the SOS-LUX test, which represents the radiobiological part of the German space experiment "Gene, immune and cellular responses to single and combined space flight conditions (TRIPLE-LUX)" which has been selected by the IDI/USRA Peer Review Panel for NASA/ESA to be performed on the International Space Station (ISS). It will supply basic information on the genotoxic response to radiation applied in microgravity. The biological end-point under investigation will depend on the bacterial SOS response brought about by genetically modified bacteria that are transformed with the pSWITCH plasmid (constructed from the plasmids pPLS-1 and pGFPuv). The luminescent/fluorescent bioassay SWITCH (SWITCH: Salmonella Weighting of Induced Toxicity Cyto/GenoTox for Human Health) as successor of the SOS-LUX test for rapid toxicity (genotoxicity and cytotoxicity) testing, makes use of two sensing and reporting systems for the two biological endpoints under investigation: the SOS-LUX test and the LAC- Fluoro test. The SWITCH plasmid carries the promoterless lux operon of Photobacterium leiognathi as reporter element under the control of the DNA-damage-dependent SOS promoter of ColD as sensor element (for genotoxicity testing) and the sequences for a hybrid protein consisting of β-galactosidase and GFPuv of Aequorea victoria as reporter element under the control of the (in Salmonella constitutively active) LAC promoter of Escherichia coli as sensor element (for cytotoxicity testing). The system has worked properly for terrestrial applications during the first experiments. Experiments using X-rays and UV radiation of various qualities (from UVC to UVA) have given insights into cellular mechanisms relevant for estimation of health risks, resulting from exposure of astronauts to the extraordinary radiation environment of space.

Evaluation of copper toxicity using site specific algae and water chemistry: Field validation of laboratory bioassays.

PubMed

Fawaz, Elyssa G; Salam, Darine A; Kamareddine, Lina

2018-07-15

Studies of metal toxicity to microalgae have predominantly been conducted using single non-target algae species and without due regard for the chemistry of the treated waters, leading to ineffective or excessive algaecide treatments. In this study, indigenous multi-algal species (Scenedesmus quadricauda, and Scenedesmus subspicatus and Oscillatoria agardhii) were used in laboratory toxicity bioassays under simulated field water chemistry (pH = 7.2, hardness = 196 mg L -1 as CaCO 3 , and alkalinity = 222 mg L -1 as CaCO 3 ) to determine the optimum copper sulfate treatment dose to control algae growth in an irrigation canal. Toxicity bioassays were conducted using copper sulfate in chelated (with EDTA) and non-chelated (without EDTA) forms to assess the influence of the use of synthetic chelators in toxicity studies. Also, copper toxicity to the indigenous algae species was measured in the non-modified EPA test medium (pH = 7.5, hardness = 92 mg L -1 as CaCO 3 , alkalinity = 10 mg L -1 as CaCO 3 and EDTA= 300 µg L -1 ) to assess the impact of the water chemistry on algae inhibitory algal dosages. Under simulated water chemistry conditions, lower toxicity was measured in the test flasks with the chelated form of copper (96 h- EC 50 = 386.67 µg L -1 as Cu) as compared to those with the non-chelated metal (96 h-EC 50 = 217.17 µg L -1 as Cu). In addition, higher copper toxicity was measured in the test flasks prepared with the non-modified EPA medium using chelated copper (96 h-EC 50 = 65.93 µg L -1 as Cu) as compared to their analogous microcosms with modified water chemistry (96 h-EC 50 = 386.67 µg L -1 as Cu), the increased water hardness and alkalinity in the latter case contributing to the decrease of the metal bioavailability. Results from laboratory experiments showed good correlation with copper dosages used in a small scale field testing to control algae growth, increasing confidence in laboratory bioassays. Copyright © 2018 Elsevier Inc. All rights reserved.

Analysing the oviposition behaviour of malaria mosquitoes: design considerations for improving two-choice egg count experiments.

PubMed

Okal, Michael N; Lindh, Jenny M; Torr, Steve J; Masinde, Elizabeth; Orindi, Benedict; Lindsay, Steve W; Fillinger, Ulrike

2015-06-20

Choice egg-count bioassays are a popular tool for analysing oviposition substrate preferences of gravid mosquitoes. This study aimed at improving the design of two-choice experiments for measuring oviposition substrates preferences of the malaria vector Anopheles gambiae senso lato, a mosquito that lays single eggs. In order to achieve high egg-laying success of female An. gambiae sensu stricto (s.s.) and Anopheles arabiensis mosquitoes in experiments, four factors were evaluated: (1) the time provided for mating; (2) the impact of cage size, mosquito age and female body size on insemination; (3) the peak oviposition time; and, (4) the host sources of blood meal. Choice bioassays, with one mosquito released in each cage containing two oviposition cups both with the same oviposition substrate (100 ml water), were used to measure and adjust for egg-laying characteristics of the species. Based on these characteristics an improved design for the egg-count bioassay is proposed. High oviposition rates [84%, 95% confidence interval (CI) 77-89%] were achieved when 300 male and 300 blood-fed female An. gambiae s.s. were held together in a cage for 4 days. The chances for oviposition dropped (odds ratio 0.30; 95% CI 0.14-0.66) when human host source of blood meal was substituted with a rabbit but egg numbers per female were not affected. The number of eggs laid by individual mosquitoes was overdispersed (median = 52, eggs, interquartile range 1-214) and the numbers of eggs laid differed widely between replicates, leading to a highly heterogeneous variance between groups and/or rounds of experiments. Moreover, one-third of mosquitoes laid eggs unequally in both cups with similar substrates giving the illusion of choice. Sample size estimations illustrate that it takes 165 individual mosquitoes to power bioassays sufficiently (power = 0.8, p = 0.05) to detect a 15% shift in comparative preferences of two treatments. Two-choice egg count bioassays with Anopheles are best done with a two-tier design that (1) implements a parallel series of experiments with mosquitoes given a choice of two identical substrates choices and, (2) uses a single mosquito in each test cage rather than groups of mosquitoes to assess the preference of a test or control solution. This approach, with sufficient replication, lowers the risk detecting pseudopreferences.

Estuarine bed-sediment-quality data collected in New Jersey and New York after Hurricane Sandy, 2013

USGS Publications Warehouse

Fischer, Jeffrey M.; Phillips, Patrick J.; Reilly, Timothy J.; Focazio, Michael J.; Loftin, Keith A.; Benzel, William M.; Jones, Daniel K.; Smalling, Kelly L.; Fisher, Shawn C.; Fisher, Irene J.; Iwanowicz, Luke R.; Romanok, Kristin M.; Jenkins, Darkus E.; Bowers, Luke; Boehlke, Adam; Foreman, William T.; Deetz, Anna C.; Carper, Lisa G.; Imbrigiotta, Thomas E.; Birdwell, Justin E.

2015-01-01

Bed-sediment samples were collected from June to October 2013 from 167 estuarine sites extending from Cape May, New Jersey, to the New York Harbor and the eastern end of Long Island. Each sampling location and study region was characterized by using geographic information to identify potential contaminant sources. Characterizations included land cover, locations and types of businesses (industrial, financial, and others), spills (sewage, chemical, and others), bulk storage facilities, effluent discharges within 2 kilometers of the sampling point, and discharges within inundated and non-inundated regions near the sampling location. Samples were analyzed for particle size, total organic carbon, metals and trace elements, semivolatile organic compounds, wastewater compounds, hormones, and sediment toxicity. Samples were also screened using x-ray fluorescence, Fourier transform infrared spectroscopy, and x-ray diffraction. In addition, bioassays for endocrine disruptors and protein phosphatase 2A inhibition were conducted. The study was designed to provide the data needed to understand the extent and sources of contamination resulting from Hurricane Sandy, to compare the chemistry and toxicity of estuarine bed sediments before and after the storm, and to evaluate the usefulness of rapid screening and bioassay approaches in disaster settings.

Methods for the isolation and identification of polycyclic aromatic hydrocarbons found in complex mixtures and the determination of their possible toxicity by means of a host mediated bioassay technique. Progress report, July 1, 1976--February 1, 1977. [Cultured mouse leumemia cell bioassay system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lipsky, S.R.; Alexander, G.; McMurray, W.

1977-02-01

Techniques were developed to produce excellent high performance glass capillary columns for gas chromatographic analyses of a wide range of complex mixtures of organic compounds, including those containing a wide array of polycyclic aromatic hydrocarbons (PAH) derived from a coal liquefaction process. Work was begun to assess the potential mutogenicity and/or carcinogenicity of the various isolated PAH fractions utilizing a unique host mediated bioassay system. Preliminary results indicate that further efforts will be required to determine dose response parameters of cultured mouse leukemia cells, as well as suitable vehicles for the satisfactory introduction of certain PAH fractions into this particularmore » bioassay system.« less

Sensitivity of mouse bioassay in clinical wound botulism.

PubMed

Wheeler, Charlotte; Inami, Gregory; Mohle-Boetani, Janet; Vugia, Duc

2009-06-15

California has an ongoing epidemic of wound botulism (WB) among injection drug users (IDUs). We retrospectively studied a cohort of patients with WB and determined the sensitivity of the mouse bioassay-the gold standard laboratory test for confirmation of botulism-in verifying WB. We defined a clinical case of WB as an acute, bilateral, descending, flaccid paralysis starting with 1 cranial nerve palsies in an IDU with no other explainable diagnosis. We calculated the sensitivity of the mouse bioassay as the proportion of clinical WB cases that had positive serum toxin test results by mouse bioassay. We compared serum toxin-positive with serum toxin-negative patients. Of 73 patients with WB, 50 tested serum toxin positive, yielding a sensitivity of 68%. Serum toxin-positive patients did not differ significantly from serum toxin-negative patients with respect to demographic characteristics or injection drug use practices or in days from patient symptom onset to collection of specimens for testing. Patients did not differ significantly by clinical characteristics, except that serum toxin-positive patients were more likely than serum toxin-negative patients to have required mechanical ventilation during their hospital courses (74% vs. 43%; P = .01). In this study, the mouse bioassay failed to detect botulinum toxin in the serum samples of nearly one-third of IDUs with characteristic WB. Such patients should be considered to have probable WB. Physicians should be aware of the test's limitations and base their final diagnosis of suspected WB on clinical criteria when the mouse bioassay produces negative results.

Natural products phytotoxicity A bioassay suitable for small quantities of slightly water-soluble compounds.

PubMed

Dornbos, D L; Spencer, G F

1990-02-01

A large variety of secondary metabolites that can inhibit germination and/or seedling growth are produced by plants in low quantities. The objective of this study was to develop a bioassay capable of reliably assessing reductions in germination percentage and seedling length of small-seeded plant species caused by exposure to minute quantities of these compounds. The germination and growth of alfalfa (Medicago saliva), annual ryegrass (Lolium multiflorum), and velvetleaf (Abutilon theophrasti) were evaluated against six known phytotoxins from five chemical classes; cinmethylin (a herbicidal cineole derivative) was selected as a comparison standard. Each phytotoxin, dissolved in a suitable organic solvent, was placed on water-agar in small tissue culture wells. After the solvent evaporated, imbibed seeds were placed on the agar; after three days, germination percentages and seedling lengths were measured. Compared to a commonly used filter paper procedure, this modified agar bioassay required smaller quantities of compound per seed for comparable bioassay results. This bioassay also readily permitted the measurement of seedling length, a more sensitive indicator of phytotoxicity than germination. Seedling length decreased sigmoidally as the toxin concentration increased logarithmically. Phytotoxicity was a function of both compound and plant species. Cinmethylin, a grass herbicide, reduced the length of annual ryegrass seedlings by 90-100%, whereas that of alfalfa and velvetleaf was inhibited slightly. The agar bioassay facilitated the rapid and reliable testing of slightly water-soluble compounds, requiring only minute quantities of each compound to give reproducible results.

Development of a dual luciferase activity and fluorescamine protein assay adapted to a 384 micro-well plate format: Reducing variability in human luciferase transactivation cell lines aimed at endocrine active substances.

PubMed

Brennan, Jennifer C; Tillitt, Donald E

2018-03-01

There is a need to adapt cell bioassays to 384-well and 1536-well formats instead of the traditional 96-well format as high-throughput screening (HTS) demands increase. However, the sensitivity and performance of the bioassay must be re-verified in these higher micro-well plates, and verification of cell health must also be HT (high-throughput). We have adapted two commonly used human breast luciferase transactivation cell bioassays, the recently re-named estrogen agonist/antagonist screening VM7Luc4E2 cell bioassay (previously designated BG1Luc4E2) and the androgen/glucocorticoid screening MDA-kb2 cell bioassay, to 384-well formats for HTS of endocrine-active substances (EASs). This cost-saving adaptation includes a fast, accurate, and easy measurement of protein amount in each well via the fluorescamine assay with which to normalize luciferase activity of cell lysates without requiring any transfer of the cell lysates. Here we demonstrate that by accounting for protein amount in the cell lysates, antagonistic agents can easily be distinguished from cytotoxic agents in the MDA-kb2 and VM7Luc4E2 cell bioassays. Additionally, we demonstrate via the fluorescamine assay improved interpretation of luciferase activity in wells along the edge of the plate (the so-called "edge effect"), thereby increasing usable wells to the entire plate, not just interior wells. Published by Elsevier Ltd.

Development of a dual luciferase activity and fluorescamine protein assay adapted to a 384 micro-well plate format: Reducing variability in human luciferase transactivation cell lines aimed at endocrine active substances

USGS Publications Warehouse

Brennan, Jennifer; Tillitt, Donald E.

2018-01-01

There is a need to adapt cell bioassays to 384-well and 1536-well formats instead of the traditional 96-well format as high-throughput screening (HTS) demands increase. However, the sensitivity and performance of the bioassay must be re-verified in these higher micro-well plates, and verification of cell health must also be HT (high-throughput). We have adapted two commonly used human breast luciferase transactivation cell bioassays, the recently re-named estrogen agonist/antagonist screening VM7Luc4E2 cell bioassay (previously designated BG1Luc4E2) and the androgen/glucocorticoid screening MDA-kb2 cell bioassay, to 384-well formats for HTS of endocrine-active substances (EASs). This cost-saving adaptation includes a fast, accurate, and easy measurement of protein amount in each well via the fluorescamine assay with which to normalize luciferase activity of cell lysates without requiring any transfer of the cell lysates. Here we demonstrate that by accounting for protein amount in the cell lysates, antagonistic agents can easily be distinguished from cytotoxic agents in the MDA-kb2 and VM7Luc4E2 cell bioassays. Additionally, we demonstrate via the fluorescamine assay improved interpretation of luciferase activity in wells along the edge of the plate (the so-called “edge effect”), thereby increasing usable wells to the entire plate, not just interior wells.

Assay optimisation and technology transfer for multi-site immuno-monitoring in vaccine trials

PubMed Central

Harris, Stephanie A.; Satti, Iman; Bryan, Donna; Walker, K. Barry; Dockrell, Hazel M.; McShane, Helen; Ho, Mei Mei

2017-01-01

Cellular immunological assays are important tools for the monitoring of responses to T-cell-inducing vaccine candidates. As these bioassays are often technically complex and require considerable experience, careful technology transfer between laboratories is critical if high quality, reproducible data that allows comparison between sites, is to be generated. The aim of this study, funded by the European Union Framework Program 7-funded TRANSVAC project, was to optimise Standard Operating Procedures and the technology transfer process to maximise the reproducibility of three bioassays for interferon-gamma responses: enzyme-linked immunosorbent assay (ELISA), ex-vivo enzyme-linked immunospot and intracellular cytokine staining. We found that the initial variability in results generated across three different laboratories reduced following a combination of Standard Operating Procedure harmonisation and the undertaking of side-by-side training sessions in which assay operators performed each assay in the presence of an assay ‘lead’ operator. Mean inter-site coefficients of variance reduced following this training session when compared with the pre-training values, most notably for the ELISA assay. There was a trend for increased inter-site variability at lower response magnitudes for the ELISA and intracellular cytokine staining assays. In conclusion, we recommend that on-site operator training is an essential component of the assay technology transfer process and combined with harmonised Standard Operating Procedures will improve the quality, reproducibility and comparability of data produced across different laboratories. These data may be helpful in ongoing discussions of the potential risk/benefit of centralised immunological assay strategies for large clinical trials versus decentralised units. PMID:29020010

Toxicity of waters from the St. Lawrence River at Massena Area-of-Concern to the plankton species Selenastrum capricornutum and Ceriodaphnia dubia

USGS Publications Warehouse

Baldigo, Barry P.; Duffy, Brian T.; Nally, Christopher J.; David, Anthony M.

2012-01-01

In 1972, the US and Canada committed to restore the chemical, physical, and biological integrity of the Great Lakes Ecosystem under the first Great Lakes Water Quality Agreement. During subsequent amendments, part of the St. Lawrence River at Massena NY, and segments of three tributaries, were designated as one Area of Concern (AOC) due to various beneficial use impairments (BUIs). Plankton beneficial use was designated impaired within this AOC because phytoplankton and zooplankton population data were unavailable or needed “further assessment”. Contaminated sediments from industrial waste disposal have been largely remediated, thus, the plankton BUI may currently be obsolete. The St. Lawrence River at Massena AOC remedial action plan established two criteria which may be used to assess the plankton BUI; the second states that, “in the absence of community structure data, plankton bioassays confirm no toxicity impact in ambient waters”. This study was implemented during 2011 to determine whether this criterion was achieved. Acute toxicity and chronic toxicity of local waters were quantified seasonally using standardized bioassays with green alga Selenastrum capricornutum and water flea Ceriodaphnia dubia to test the hypothesis that waters from sites within the AOC were no more toxic than were waters from adjacent reference sites. The results of univariate and multivariate analyses confirm that ambient waters from most AOC sites (and seasons) were not toxic to both species. Assuming both test species represent natural plankton assemblages, the quality of surface waters throughout most of this AOC should not seriously impair the health of resident plankton communities.

Evaluation of tests to assess the quality of mine-contaminated soils.

PubMed

Alvarenga, P; Palma, P; Gonçalves, A P; Fernandes, R M; de Varennes, A; Vallini, G; Duarte, E; Cunha-Queda, A C

2008-04-01

An acid metal-contaminated soil from the Aljustrel mining area (a pyrite mine located in SW Portugal in the Iberian Pyrite Belt) was subjected to chemical characterisation and total metal quantification (Cd, Cr, Cu, Ni, Pb and Zn). Water-soluble metals were determined and a sequential extraction procedure was used to investigate metal speciation. Two bioavailable metal fractions were determined: a mobile fraction and a mobilisable fraction. Soil ecotoxicity was studied using a battery of bioassays: plant growth test and seed germination with cress (Lepidium sativum L.), earthworm (Eisenia fetida) mortality, E. fetida avoidance behaviour, luminescent inhibition of Vibrio fischeri and Daphnia magna immobilisation. Although the total content of Cu, Zn and Pb in the soil was large (362, 245 and 1,250 mg/kg dry matter, respectively), these metals were mostly structurally bound (87% for Cu, 81% for Zn and 89% for Pb) and, therefore, scarcely bioavailable. Nonetheless, the D. magna immobilization test using soil leachate showed an EC50 (48 h) of 36.3% (v/v), and the luminescent inhibition of V. fischeri presented an EC20 (15 min) of 45.2% and an EC20 (30 min) of 10.7% (v/v), suggesting a considerable toxic effect. In the direct exposure bioassays, E. fetida avoided the mine soil at the highest concentrations (50%, 75% and 100% v/v). At the same soil concentrations, cress showed negligible growth. The results suggest the need to use a battery of toxicity tests, in conjunction with chemical methods, in order to assess the quality of mine-contaminated soils correctly.

Boll weevil (Coleoptera: Curculionidae) bait sticks: Toxicity and malathion content

Treesearch

Eric J. Villavaso; Joseph E. Mulrooney; William L. Mcgovern

2003-01-01

Assays of malathion content and toxicity to boll weevil, Anll~onorni~gsr andis granrlis Boheman, were conducted on boll weevil bait sticks, now marketed as Boll Weevil Attract ancl Control Tubes (BWACTs: Plato Industries, Houston, TX). In general. the longer BWACTs were in the field, the lower the mortality of weevils that were exposed to them. Bioassays of weevil...

Evaluation of metaflumizone granular fly bait for management of houseflies.

PubMed

Ahmad, A; Zurek, L

2009-06-01

The housefly, Musca domestica L. (Diptera: Muscidae), is a pest of great veterinary and public health importance. In this study, the efficacy of metaflumizone granular fly bait was assessed on first generation (F1) housefly adults raised from flies collected at a cattle feedlot in Kansas. All bioassays were conducted as choice tests, with flies having ad libitum access to water, granular sugar and bait. A commercial methomyl-based bait (Golden Malrin) was used as positive control; no bait (water and granular sugar only) was used as negative control. Fly mortality was recorded on days 2, 7 and 14. The metaflumizone bait was significantly more slow-acting than the methomyl bait (mortality rates after 2 days of exposure were 49.9% and 57.9%, respectively). However, there were no significant differences in cumulative mortality later in the bioassays. Cumulative mortality rates on days 7 and 14 were 96.1% (metaflumizone), 91.4% (methomyl) and 99.0% (metaflumizone), 97.6% (methomyl), respectively. Our results demonstrate that the metaflumizone granular fly bait may be an effective modality for incorporation into management programmes for houseflies in and around livestock production facilities as well as in residential settings.

Dermal oncogenicity bioassays of monofunctional and multifunctional acrylates and acrylate-based oligomers.

PubMed

DePass, L R; Maronpot, R R; Weil, C S

1985-01-01

Several important components of photocurable coatings were studied for dermal tumorigenic activity by repeated application to the skin of mice. The substances tested were 2-ethylhexyl acrylate (EHA) and methylcarbamoyloxyethyl acrylate (MCEA) (monomers); neopentyl glycol diacrylate (NPGDA), esterdiol-204-diacrylate (EDDA), and pentaerythritol tri(tetra)acrylate (PETA) (cross-linkers); and three acrylated urethane oligomers. For each bioassay, 40 C3H/HeJ male mice were dosed 3 times weekly on the dorsal skin for their lifetime with the highest dose of the test agent that caused no local irritation or reduction in body weight gain. Two negative control groups received acetone (diluent) only. A positive control group received 0.2% methylcholanthrene (MC). NPGDA and EHA had significant tumorigenic activity with tumor yields of eight and six tumor-bearing mice (three and two malignancies), respectively. The MC group had 34 mice with carcinomas and 1 additional mouse with a papilloma. MCEA had no dermal tumorigenic activity but resulted in early mortality. No skin tumors in the treatment area were observed in the other groups. Additional studies will be necessary to elucidate possible relationships between structure and tumorigenic activity for the acrylates.

Development of RNAi method for screening candidate genes to control emerald ash borer, Agrilus planipennis.

PubMed

Rodrigues, Thais B; Rieske, Lynne K; J Duan, Jian; Mogilicherla, Kanakachari; Palli, Subba R

2017-08-07

The ingestion of double-strand RNAs (dsRNA) targeting essential genes in an insect could cause mortality. Based on this principle, a new generation of insect control methods using RNA interference (RNAi) are being developed. In this work, we developed a bioassay for oral delivery of dsRNA to an invasive forest and urban tree pest, the emerald ash borer (EAB, Agrilus planipennis). EAB feeds and develops beneath the bark, killing trees rapidly. This behavior, coupled with the lack of a reliable artificial diet for rearing larvae and adults, make them difficult to study. We found that dsRNA is transported and processed to siRNAs by EAB larvae within 72 h after ingestion. Also, feeding neonate larvae with IAP (inhibitor of apoptosis) or COP (COPI coatomer, β subunit) dsRNA silenced their target genes and caused mortality. Both an increase in the concentration of dsRNA fed and sequential feeding of two different dsRNAs increased mortality. Here we provide evidence for successful RNAi in EAB, and demonstrate the development of a rapid and effective bioassay for oral delivery of dsRNA to screen additional genes.

Oxygen respirometry to assess stability and maturity of composted municipal solid waste

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iannotti, D.A.; Grebus, M.E.; Toth, B.L.

1994-11-01

The stability and maturity of compost prepared from municipal solid waste (MSW) at a full-scale composting plant was assessed through chemical, physical, and biological assays. Respiration bioassays used to determine stability (O{sub 2} and CO{sub 2} respirometry) were sensitive to process control problems at the composting plant and indicated increasing stability with time. Radish (Raphanus sativus L.) and ryegrass (Lolium perenne L.) growth bioassays revealed that immature compost samples inhibited growth. Growth of ryegrass in potting mix prepared with cured compost not amended with fertilizer was enhanced as compared to a pest control. Garden cress (Lepidium sativum L.) seed germination,more » used as an indicator of phytotoxicity, revealed inhibition of germination at all compost maturity levels. The phytotoxicity was though to be salt-related. Spearman rank-order correlations demonstrated that O{sub 2} respirometry, water-soluble organic C, and the water extract organic C to organic N ratio, significantly correlated with compost age and best indicated an acceptable level of stability. Oxygen respirometry also best predicted the potential for ryegrass growth, and an acceptable level of compost maturity. 31 refs., 4 figs., 5 tabs.« less

Neural and neuroendocrine adaptations to microgravity and ground-based models of microgravity.

PubMed

Edgerton, V R; Roy, R R; Recktenwald, M R; Hodgson, J A; Grindeland, R E; Kozlovskaya, I

2000-12-01

The functional properties of the motor system of humans and non-human primates are readily responsive to microgravity. There is a growing body of evidence that significant adaptations occur in the spinal cord and muscle in response to prolonged exposure to microgravity. Further, there is evidence that the processing of sensory information from the periphery, particularly that input associated with the function of muscle tendons and joints, is significantly altered as a result of prolonged microgravity. We present evidence that the fundamental neural mechanisms that control the relative activity of the motor pools of a slow and fast extensor muscle is changed such that a slow, postural muscle is less readily activated during locomotion following spaceflight. Another type of change observed in mammals exposed to spaceflight relates to the release of a growth factor, called bioassayable growth hormone, which is thought to be released from the pituitary. When an individual generates a series of isometric plantarflexor contractions, the plasma levels of bioassayable growth hormone increases significantly. This response is suppressed after several days of continuous bedrest or spaceflight. These results suggest a unique neuroendocrine control system and demonstrate its sensitivity to chronic patterns of proprioceptive input associated with load-bearing locomotion.

Bioassay of 4'-(chloroacetyl)-acetanilide for possible carcinogenicity.

PubMed

1979-01-01

A bioassay for the possible carcinogenicity of 4'-(chloroacetyl)-acetanilide was conducted using Fischer 344 rats and B6C3F1 mice. 4'-(Chloroacetyl)-acetanilide was administered in the feed, at either of two concentrations, to groups of 50 male and 50 female animals of each species. Twenty animals of each sex and species were placed on test as controls. The high and low dietary concentrations of 4'-(chloroacetyl)-acetanilide were, respectively, 2,000 and 1,000 ppm for rats and 10,000 and 5,000 ppm for mice. The compound was administered for 87 weeks of a 102-week period in rats and for 90 weeks of a 105-week period in mice. Mice were killed at the end of the last week of compound administration, while rats were observed for 1 week after compound administration ceased. There were no significant positive associations between the concentration of 4'-(chloroacetyl)-acetanilide administered and mortality in rats or mice of either sex. Adequate numbers of animals in all groups survived sufficiently long to be at risk from late-developing tumors. Dose-related mean body weight depression was observed for males and females of both species, indicating that the concentrations of 4'-(chloroacetyl)-acetanilide administered to the animals in this bioassay may have approximated the maximum tolerated concentrations. None of the statistical tests for any site in rats of either sex or in male mice indicated a significant positive association between compound administration and tumor incidence. Although there was a significant positive association between the concentration of the compound administered and the incidences of hepatocellular adenomas in female mice, the Fischer exact comparisons were not significant. Under the conditions of this bioassay, 4'-(chloroacetyl)-acetanilide was not carcinogenic when administered in the diet to Fischer 344 rats or B6C3F1 mice of either sex.

Bioassay of safinamide in biological fluids of humans and various animal species.

PubMed

Dal Bo, Lorenzo; Mazzucchelli, Paolo; Fibbioli, Monia; Marzo, Antonio

2006-01-01

This paper describes three methods to bioassay safinamide (CAS 133865-89-1) in biological fluids of humans and laboratory animals for pharmacokinetic, toxicokinetic and bioavailability studies. Two methods profited from liquid chromatography tandem mass spectrometry (LC-MS-MS) system, one (micro bioassay) working in the low dynamic range 0.5-20 ng/ml, the other in the range 20-6000 ng/ml. A third method used high-performance liquid chromatrography with fluorimetric detection (HPLC-FD), working in the dynamic range 20-1000 ng/ml. All the three methods were validated in compliance with the accreditated views on analytical bioassays. The shorter run time (5.5 min vs 16 min) has led the authors to prefer the two LC-MS-MS methods to the HPLC-FD bioassay, even if all the performances of the three methods were excellent. The methods described in this paper were and are still now extensively used to assay safinamide in more than 10,000 specimens of biological fluids from humans and laboratory animals in the development program of the drug. Main pharmacokinetic results obtained in various Phase I trials on healthy volunteers are briefly reported.

Development, optimization and validation of a rapid colorimetric microplate bioassay for neomycin sulfate in pharmaceutical drug products.

PubMed

Francisco, Fabiane Lacerda; Saviano, Alessandro Morais; Pinto, Terezinha de Jesus Andreoli; Lourenço, Felipe Rebello

2014-08-01

Microbiological assays have been used to evaluate antimicrobial activity since the discovery of the first antibiotics. Despite their limitations, microbiological assays are widely employed to determine antibiotic potency of pharmaceutical dosage forms, since they provide a measure of biological activity. The aim of this work is to develop, optimize and validate a rapid colorimetric microplate bioassay for the potency of neomycin in pharmaceutical drug products. Factorial and response surface methodologies were used in the development and optimization of the choice of microorganism, culture medium composition, amount of inoculum, triphenyltetrazolium chloride (TTC) concentration and neomycin concentration. The optimized bioassay method was validated by the assessment of linearity (range 3.0 to 5.0μg/mL, r=0.998 and 0.994 for standard and sample curves, respectively), precision (relative standard deviation (RSD) of 2.8% and 4.0 for repeatability and intermediate precision, respectively), accuracy (mean recovery=100.2%) and robustness. Statistical analysis showed equivalency between agar diffusion microbiological assay and rapid colorimetric microplate bioassay. In addition, microplate bioassay had advantages concerning the sensitivity of response, time of incubation, and amount of culture medium and solutions required. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, J.M.; Callahan, C.A.; Cline, J.F.

Bioassays were used in a three-phase research project to assess the comparative sensitivity of test organisms to known chemicals, determine if the chemical components in field soil and water samples containing unknown contaminants could be inferred from our laboratory studies using known chemicals, and to investigate kriging (a relatively new statistical mapping technique) and bioassays as methods to define the areal extent of chemical contamination. The algal assay generally was most sensitive to samples of pure chemicals, soil elutriates and water from eight sites with known chemical contamination. Bioassays of nine samples of unknown chemical composition from the Rocky Mountainmore » Arsenal (RMA) site showed that a lettuce seed soil contact phytoassay was most sensitive. In general, our bioassays can be used to broadly identify toxic components of contaminated soil. Nearly pure compounds of insecticides and herbicides were less toxic in the sensitive bioassays than were the counterpart commercial formulations. This finding indicates that chemical analysis alone may fail to correctly rate the severity of environmental toxicity. Finally, we used the lettuce seed phytoassay and kriging techniques in a field study at RMA to demonstrate the feasibility of mapping contamination to aid in cleanup decisions. 25 references, 9 figures, 9 tables.« less

RECOMMENDATIONS FOR UO3 PLANT BIOASSAY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.

2010-07-12

Alternative urine bioassay programs are described for application with decontamination and decommissioning activities at the Hanford UO3 Plant. The alternatives are based on quarterly or monthly urine bioassay for recycled uranium, assuming multiple acute inhalation intakes of recycled uranium occurring over a year. The inhalations are assumed to be 5µm AMAD particles of 80% absorption type F and 20% absorption type M. Screening levels, expressed as daily uranium mass excretion rates in urine, and the actions associated with these levels are provided for both quarterly and monthly sampling frequencies.

Integration of Microfractionation, qNMR and Zebrafish Screening for the In Vivo Bioassay-Guided Isolation and Quantitative Bioactivity Analysis of Natural Products

PubMed Central

Maes, Jan; Siverio-Mota, Dany; Marcourt, Laurence; Munck, Sebastian; Kamuhabwa, Appolinary R.; Moshi, Mainen J.; Esguerra, Camila V.; de Witte, Peter A. M.; Crawford, Alexander D.; Wolfender, Jean-Luc

2013-01-01

Natural products (NPs) are an attractive source of chemical diversity for small-molecule drug discovery. Several challenges nevertheless persist with respect to NP discovery, including the time and effort required for bioassay-guided isolation of bioactive NPs, and the limited biomedical relevance to date of in vitro bioassays used in this context. With regard to bioassays, zebrafish have recently emerged as an effective model system for chemical biology, allowing in vivo high-content screens that are compatible with microgram amounts of compound. For the deconvolution of the complex extracts into their individual constituents, recent progress has been achieved on several fronts as analytical techniques now enable the rapid microfractionation of extracts, and microflow NMR methods have developed to the point of allowing the identification of microgram amounts of NPs. Here we combine advanced analytical methods with high-content screening in zebrafish to create an integrated platform for microgram-scale, in vivo NP discovery. We use this platform for the bioassay-guided fractionation of an East African medicinal plant, Rhynchosia viscosa, resulting in the identification of both known and novel isoflavone derivatives with anti-angiogenic and anti-inflammatory activity. Quantitative microflow NMR is used both to determine the structure of bioactive compounds and to quantify them for direct dose-response experiments at the microgram scale. The key advantages of this approach are (1) the microgram scale at which both biological and analytical experiments can be performed, (2) the speed and the rationality of the bioassay-guided fractionation – generic for NP extracts of diverse origin – that requires only limited sample-specific optimization and (3) the use of microflow NMR for quantification, enabling the identification and dose-response experiments with only tens of micrograms of each compound. This study demonstrates that a complete in vivo bioassay-guided fractionation can be performed with only 20 mg of NP extract within a few days. PMID:23700445

Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor-LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn.

PubMed

Giuliani, Cesidio; Saji, Motoyasu; Bucci, Ines; Napolitano, Giorgio

2016-01-01

Since the discovery 60 years ago of the "long-acting thyroid stimulator" by Adams and Purves, great progress has been made in the detection of thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) in Graves' disease. Today, commercial assays are available that can detect TRAbs with high accuracy and provide diagnostic and prognostic evaluation of patients with Graves' disease. The present review focuses on the development of TRAbs bioassays, and particularly on the role that Leonard D. Kohn had in this. Indeed, 30 years ago, the Kohn group developed a bioassay based on the use of FRTL-5 cells that was characterized by high reproducibility, feasibility, and diagnostic accuracy. Using this FRTL-5 bioassay, Kohn and his colleagues were the first to develop monoclonal antibodies (moAbs) against the TSHR. Furthermore, they demonstrated the multifaceted functional nature of TRAbs in patients with Graves' disease, with the identification of stimulating and blocking TRAbs, and even antibodies that activated pathways other than cAMP. After the cloning of the TSHR, the Kohn laboratory constructed human TSHR-rat luteinizing hormone/chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of non-thyroid cells transfected with the Mc4 chimera. The new Mc4 bioassay is characterized by high diagnostic and prognostic accuracy, greater than for other assays. The availability of a commercial kit based on the Mc4 chimera is spreading the use of this assay worldwide, indicating its benefits for these patients with Graves' disease. This review also describes the main contributions made by other researchers in TSHR molecular biology and TRAbs assay, especially with the development of highly potent moAbs. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided.

Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor–LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn

PubMed Central

Giuliani, Cesidio; Saji, Motoyasu; Bucci, Ines; Napolitano, Giorgio

2016-01-01

Since the discovery 60 years ago of the “long-acting thyroid stimulator” by Adams and Purves, great progress has been made in the detection of thyroid-stimulating hormone (TSH) receptor (TSHR) autoantibodies (TRAbs) in Graves’ disease. Today, commercial assays are available that can detect TRAbs with high accuracy and provide diagnostic and prognostic evaluation of patients with Graves’ disease. The present review focuses on the development of TRAbs bioassays, and particularly on the role that Leonard D. Kohn had in this. Indeed, 30 years ago, the Kohn group developed a bioassay based on the use of FRTL-5 cells that was characterized by high reproducibility, feasibility, and diagnostic accuracy. Using this FRTL-5 bioassay, Kohn and his colleagues were the first to develop monoclonal antibodies (moAbs) against the TSHR. Furthermore, they demonstrated the multifaceted functional nature of TRAbs in patients with Graves’ disease, with the identification of stimulating and blocking TRAbs, and even antibodies that activated pathways other than cAMP. After the cloning of the TSHR, the Kohn laboratory constructed human TSHR–rat luteinizing hormone/chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of non-thyroid cells transfected with the Mc4 chimera. The new Mc4 bioassay is characterized by high diagnostic and prognostic accuracy, greater than for other assays. The availability of a commercial kit based on the Mc4 chimera is spreading the use of this assay worldwide, indicating its benefits for these patients with Graves’ disease. This review also describes the main contributions made by other researchers in TSHR molecular biology and TRAbs assay, especially with the development of highly potent moAbs. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided. PMID:27504107

INTRODUCTION AND STUDY DESIGN

EPA Science Inventory

Under the sponsorship of the UNEP/ILO/IPCS, 17 laboratories from diverse regions of the world participated in evaluating the utility of four plant bioassays for detecting genetic hazards of environmental chemicals. he bioassays included in this collaborative study were Arabidopsi...

Bioassay-Directed Fractionation of Diesel and Biodiesel Emissions

EPA Science Inventory

Biofuels are being developed as alternatives to petroleum-derived products, but published research is contradictory regarding the mutagenic activity of such emissions relative to those from petroleum diesel. We performed bioassay-directed fractionation and analyzed the polycyclic...

Determination of ametryn herbicide by bioassay and gas chromatography-mass spectrometry in analysis of residues in drinking water.

PubMed

Queiroz, R H; Lanchote, V L; Bonato, P S; Tozato, E; de Carvalho, D; Gomes, M A; Cerdeira, A L

1999-06-01

A simple, rapid and quantitative bioassay method was compared to a gas chromatography/mass spectrometry (GC/MS) procedure for the analysis of ametryn in surface and groundwater. This method was based on the activity of ametryn in inhibiting the growth of the primary root and shoot of germinating letuce, Lactuca sativa L. seed. The procedure was sensitive to 0.01 microgram/l and was applicable from this concentration up to 0.6 microgram/l. Initial surface sterilization of the seed, selection of pregerminated seed of certain root lengths and special equipment are not necessary. So, we concluded that the sensitivity of the bioassay method is compatible with the chromatographic method (GC-MS). However, the study of the correlation between methods suggests that the bioassay should be used only as a screening technique for the evaluation of ametryn residues in water.

A rapid and inexpensive bioassay to evaluate the decontamination of organophosphates.

PubMed

Claborn, David M; Martin-Brown, Skylar A; Sagar, Sanjay Gupta; Durham, Paul

2012-01-01

An inexpensive and rapid bioassay using adult red flour beetles was developed for use in assessing the decontamination of environments containing organophosphates and related chemicals. A decontamination protocol was developed which demonstrated that 2 to 3 applications of 5% bleach solution were required to obtain nearly complete decontamination of malathion. The bioassay was also used to screen common household cleaners as potential decontaminating agents, but only 5% bleach was effective at improving survival of insects on steel plates treated with 25% malathion. A toxic degradation product (malaoxon) was detected using gas chromatography/mass spectrophotometry; this toxin affected the decontamination efficacy and resulted in continued toxicity to the beetles until subsequent decontaminations. The bioassay provides evidence to support the use of red flour beetles as a sensitive, less expensive method for determining safety levels of environments contaminated with malathion and other toxins, and may have application in the study of chemical warfare agents.

Bioassay, isolation and studies on the mechanism of action of neurite extension factor

NASA Technical Reports Server (NTRS)

Kligman, D.

1984-01-01

The identification and purification of molecules active in promoting neurite outgrowth requires a sensitive reproducible bioassay. A quantitative bioassay was utilized to purify a neurite extension factor (NEF) based on counting the number of phase bright neurons with processes at least equal to one cell body diameter after 20 hrs. in culture is defined, serum free medium. Using a combination of heat treatment DEAE cellulose chromatography and gel filtration, an acidic protein of M sub r = 75,000 was highly purified. Upon reduction, it yields subunits of M sub r = 37,000. Purified fractions are active half maximally at 100 ng/ml in inducing neurite outgrowth in this bioassay. Currently, monoclonal antibodies to NEF are being produced. Female Balb C mice were immunized with the antigen and fusions with mouse myeloma cells will be performed to yield hybridoma cells.

Requirements for radiation emergency urine bioassay techniques for the public and first responders.

PubMed

Li, Chunsheng; Vlahovich, Slavica; Dai, Xiongxin; Richardson, Richard B; Daka, Joseph N; Kramer, Gary H

2010-11-01

Following a radiation emergency, the affected public and the first responders may need to be quickly assessed for internal contamination by the radionuclides involved. Urine bioassay is one of the most commonly used methods for assessing radionuclide intake and radiation dose. This paper attempts to derive the sensitivity requirements (from inhalation exposure) for the urine bioassay techniques for the top 10 high-risk radionuclides that might be used in a terrorist attack. The requirements are based on a proposed reference dose to adults of 0.1 Sv (CED, committed effective dose). In addition, requirements related to sample turnaround time and field deployability of the assay techniques are also discussed. A review of currently available assay techniques summarized in this paper reveals that method development for ²⁴¹Am, ²²⁶Ra, ²³⁸Pu, and ⁹⁰Sr urine bioassay is needed.

A survey on uncertainty in bioassay measurements carried out within the OMINEX project.

PubMed

Hurtgen, C; Cossonnet, C

2003-01-01

One of the topics covered by the OMINEX (Optimisation of Monitoring for Internal Exposure) project was to look at the bioassay measurements performed in the European laboratories. Questionnaires on bioassay measurements by alpha spectrometry or inductively coupled plasma-mass spectrometry (ICP-MS) were sent to European laboratories. The main objective was to collect information on analytical procedures and on the uncertainties associated with bioassay results. Alpha spectrometry is the technique most often used for the determination of alpha emitters, such as actinides in biological samples. ICP-MS is not used much as yet for routine measurements of actinides in biological samples, but is very sensitive for measurements of long-lived radionuclides. The different parameters influencing the uncertainties on the results and the minimum detectable amount have been investigated. Optimum conditions for achieving low result uncertainties and high sensitivity are given for alpha spectrometry and ICP-MS.

Comparison of liquid chromatographic and bioassay procedures for determining depletion of intramuscularly injected tylosin.

PubMed

Moats, W A; Harris, E W; Steele, N C

1985-01-01

Crossbred pigs weighing 80-110 kg were injected intramuscularly in the ham with 8.8 mg/kg tylosin. Animals were slaughtered in groups of 3 at intervals of 4 h, and 1, 2, 4, and 8 days after injection, and samples of blood, injected muscle, uninjected muscle, liver, and kidney were analyzed by liquid chromatography (LC) and by bioassay using Sarcina lutea as the test organism. The LC method was far more sensitive with a detection limit of less than 0.1 ppm, while the detection limit by bioassay was about 0.5 ppm in tissue. Results by bioassay and LC sometimes differed considerably for tissue samples. Residues in all tissues were below the tolerance limit of 0.2 ppm at 24 h, except in the injected muscle in one animal. Residues were not detected in any tissue of any animal at 48 h after treatment.

Sampling method, storage and pretreatment of sediment affect AVS concentrations with consequences for bioassay responses.

PubMed

De Lange, H J; Van Griethuysen, C; Koelmans, A A

2008-01-01

Sediment treatment and sediment storage may alter sediment toxicity, and consequently biotic response. Purpose of our study was to combine these three aspects (treatment-toxicity-biotic response) in one integrated approach. We used Acid Volatile Sulfide (AVS) concentrations as a proxy of the disturbance of the sediment. AVS and Simultaneously Extracted Metal (SEM) concentrations were compared to bioassay responses with the freshwater benthic macroinvertebrate Asellus aquaticus. Storage conditions and sediment treatment affected AVS but not SEM levels. AVS can be used as a proxy for sediment disturbance. The best way to pretreat the sediment for use in a bioassay in order to maintain initial AVS conditions was to sample the sediment with an Ekman grab, immediately store it in a jar without headspace, and freeze it as soon as possible. In a survey using seven different sediments, bioassay responses of A. aquaticus were correlated with SEM and AVS characteristics.

The current status of resistance to alpha-cypermethrin, ivermectin, and amitraz of the cattle tick (Rhipicephalus microplus) in Ecuador.

PubMed

Rodríguez-Hidalgo, Richar; Pérez-Otáñez, Ximena; Garcés-Carrera, Sandra; Vanwambeke, Sophie O; Madder, Maxime; Benítez-Ortiz, Washington

2017-01-01

Rhipicephalus microplus is widely distributed in tropical and subtropical areas of the world where livestock is a principal activity with great veterinary and economic importance. In Ecuador, this hematophagous ectoparasite has been observed between 0 and 2600 masl. One of the main tick control measures is the use of acaricides, which have been indiscriminately used worldwide and in Ecuador. In this country, no studies on acaricide resistance in Rhipicephalus microplus have been published. The current study aims to characterise the level of resistance of R. microplus against three main acaricides commonly used in Ecuador i.e. amitraz, alpha-cypermethrin and ivermectin to determine the level and pattern of dose-responses for R. microplus in 12 field populations (farms). The level of acaricide resistance was evaluated using three different bioassays: adult immersion test (AIT), larval package test (LPT) and larval immersion test (LIT), as recommended by the FAO. The predictive dose-responses were analysed by binomial logistics regression of the larval survival rate (resistance). In general, we found resistance of 67% for amitraz; 50% for alpha-cypermethrin and from 25 to 42% for ivermectin in the twelve field populations analysed. Resistance levels were studied in larval and adult bioassays, respectively, which were slightly modified for this study. For larval bioassays based on corrected mortality i.e. high (above 51%), medium (21-50%) and low (11-20%) resistance, percentages less than 10% were considered as susceptible. For the adult test, two resistance levels were used i.e. high (more than 76%) and medium (51 to 75%) resistance. Percentages lower than 50% were considered as susceptible. In this context, for larval bioassays, amitraz showed 21%, 38% and 8% for high, medium and low resistance, respectively. Alpha-cypermethrin presented 8%, 4 and 38% for high, medium and low resistance, respectively. Ivermectin presented 8%, 25% and 8% for high, medium and low resistance, respectively. For adult tests with amitraz 50% and 17% of the field populations showed average and high resistance, with evidences of average resistance to alpha-cypermethrin in 50% of the samples and average resistance against ivermectin in 25% of the farms. No statistical difference amongst the three bioassays was found and acaricide resistance was confirmed by logistic regression analysis; hence resistance (dose-responses) in each field populations differed, depending on the choice of the acaricide, frequent usage, frequency of treatment and farm management. The effective estimated dose needed to eliminate 99% of ticks is higher than dose recommended by the manufacturer. In conclusion, amitraz showed the highest resistance followed by ivermectin and alpha-cypermethrin and reveals differences on resistance in each individual field population. This information is important in order to establish the monitoring of resistance on each farm individually, contributing to the rational use of acaricides included in an integrated control program for R. microplus.

The current status of resistance to alpha-cypermethrin, ivermectin, and amitraz of the cattle tick (Rhipicephalus microplus) in Ecuador

PubMed Central

Garcés-Carrera, Sandra; Vanwambeke, Sophie O.; Madder, Maxime; Benítez-Ortiz, Washington

2017-01-01

Rhipicephalus microplus is widely distributed in tropical and subtropical areas of the world where livestock is a principal activity with great veterinary and economic importance. In Ecuador, this hematophagous ectoparasite has been observed between 0 and 2600 masl. One of the main tick control measures is the use of acaricides, which have been indiscriminately used worldwide and in Ecuador. In this country, no studies on acaricide resistance in Rhipicephalus microplus have been published. The current study aims to characterise the level of resistance of R. microplus against three main acaricides commonly used in Ecuador i.e. amitraz, alpha-cypermethrin and ivermectin to determine the level and pattern of dose-responses for R. microplus in 12 field populations (farms). The level of acaricide resistance was evaluated using three different bioassays: adult immersion test (AIT), larval package test (LPT) and larval immersion test (LIT), as recommended by the FAO. The predictive dose-responses were analysed by binomial logistics regression of the larval survival rate (resistance). In general, we found resistance of 67% for amitraz; 50% for alpha-cypermethrin and from 25 to 42% for ivermectin in the twelve field populations analysed. Resistance levels were studied in larval and adult bioassays, respectively, which were slightly modified for this study. For larval bioassays based on corrected mortality i.e. high (above 51%), medium (21–50%) and low (11–20%) resistance, percentages less than 10% were considered as susceptible. For the adult test, two resistance levels were used i.e. high (more than 76%) and medium (51 to 75%) resistance. Percentages lower than 50% were considered as susceptible. In this context, for larval bioassays, amitraz showed 21%, 38% and 8% for high, medium and low resistance, respectively. Alpha-cypermethrin presented 8%, 4 and 38% for high, medium and low resistance, respectively. Ivermectin presented 8%, 25% and 8% for high, medium and low resistance, respectively. For adult tests with amitraz 50% and 17% of the field populations showed average and high resistance, with evidences of average resistance to alpha-cypermethrin in 50% of the samples and average resistance against ivermectin in 25% of the farms. No statistical difference amongst the three bioassays was found and acaricide resistance was confirmed by logistic regression analysis; hence resistance (dose-responses) in each field populations differed, depending on the choice of the acaricide, frequent usage, frequency of treatment and farm management. The effective estimated dose needed to eliminate 99% of ticks is higher than dose recommended by the manufacturer. In conclusion, amitraz showed the highest resistance followed by ivermectin and alpha-cypermethrin and reveals differences on resistance in each individual field population. This information is important in order to establish the monitoring of resistance on each farm individually, contributing to the rational use of acaricides included in an integrated control program for R. microplus. PMID:28388639

Potential of Essential Oil-Based Pesticides and Detergents for Bed Bug Control.

PubMed

Singh, Narinderpal; Wang, Changlu; Cooper, Richard

2014-12-01

The bed bug, (Cimex lectularius L.), is a difficult pest to control. Prevalence of insecticide resistance among bed bug populations and concerns over human-insecticide exposure has stimulated the development of alternative bed bug control materials. Many essential oil-based pesticides and detergent insecticides targeting bed bugs have been developed in recent years. We evaluated the efficacy of nine essential oil-based products and two detergents using direct spray and residual contact bioassays in the laboratory. Two conventional insecticides, Temprid SC (imidacloprid and β-cyfluthrin) and Demand CS (λ-cyhalothrin), were used for comparison. Among the 11 nonsynthetic insecticides tested, only EcoRaider (1% geraniol, 1% cedar extract, and 2% sodium lauryl sulfate) and Bed Bug Patrol (0.003% clove oil, 1% peppermint oil, and 1.3% sodium lauryl sulfate) caused >90% mortality of nymphs in direct spray and forced exposure residual assays. However, the efficacy of EcoRaider and Bed Bug Patrol was significantly lower than that of Temprid SC and Demand CS in choice exposure residual bioassay. Direct spray of EcoRaider caused 87% egg mortality, whereas the other nonsynthetic insecticides had little effect on bed bug eggs. EcoRaider and Bed Bug Patrol did not exhibit detectable repellency against bed bugs in the presence of a carbon dioxide source. These findings suggest that EcoRaider and Bed Bug Patrol are potentially useful pesticides for controlling bed bug infestations, but further testing in naturally infested environments is needed. © 2014 Entomological Society of America.

Physiological and Molecular Response of Prorocentrum minimum to Tannic Acid: An Experimental Study to Evaluate the Feasibility of Using Tannic Acid in Controling the Red Tide in a Eutrophic Coastal Water.

PubMed

Jeong, Byungkwan; Jeong, Eui-Suk; Malazarte, Jacqueline Martha; Sin, Yongsik

2016-05-14

Bioassay and gene expression experiments were conducted in order to evaluate the growth and physiology of Prorocentrum minimum isolated from a eutrophic coastal water in response to tannic acid. In the bioassay experiments, variations in abundance, chlorophyll (chl) a concentration, maximum fluorescence (in vivo Fm), and photosynthetic efficiency (Fv/Fm) were measured over the course of a seven-day incubation. Moreover, stress-related gene expression in both the control and an experimental (2.5 ppm TA treatment) group was observed for 24 h and 48 h. The molecular markers used in this study were the heat shock proteins (Hsp70 and Hsp90) and cyclophilin (CYP). The findings show that P. minimum can thrive and grow at low concentrations (<2.5 ppm) of tannic acid, and, above this concentration, cells begin to slow down development. In addition, TA concentration of 10 ppm halted photosynthetic activity. At the molecular level, treatment with tannic acid increased the expression of Hsp70, Hsp90, and CYP, and heat shock proteins are more upregulated than the cyclophilin gene. Exposure to tannic acid increased the expression of stress factors over time (48 h) by 10- to 27-fold the expression level of the control group. These results suggest that tannic acid can be used to control harmful algal blooms such as those containing P. minimum in eutrophic coastal waters.

Influence of entomopathogenic fungus, Metarhizium anisopliae, alone and in combination with diatomaceous earth and thiamethoxam on mortality, progeny production, mycosis, and sporulation of the stored grain insect pests.

PubMed

Ashraf, Misbah; Farooq, Muhammad; Shakeel, Muhammad; Din, Naima; Hussain, Shahbaz; Saeed, Nadia; Shakeel, Qaiser; Rajput, Nasir Ahmed

2017-12-01

The stored grain insects cause great damage to grains under storage conditions. Synthetic insecticides and fumigants are considered as key measures to control these stored grain insect pests. However, the major issue with these chemicals is grain contamination with chemical residues and development of resistance by insect pests to these chemicals. Biological control is considered as a potential alternative to chemical control especially with the use of pathogens, alone or in combination with selective insecticides. The present study was conducted to evaluate the synergism of Metarhizium anisopliae with diatomaceous earth (DE) and thiamethoxam against four insect pests on the stored wheat grains. In the first bioassay, the M. anisopliae was applied at 1.4 × 10 4 and 1.4 × 10 6 conidia/ml alone and in integration with two concentrations (250 and 500 ppm) of tested DE. The tested fungus when combined with DE and thiamethoxam possessed synergistic impact as compared to their individual efficacy. Adult mortality increased with respect to increased exposure interval and doses. In the second bioassay, M. anisopliae was applied at 1.4 × 10 4 conidia/ml individually and in combination with three concentrations (0.50, 0.75, and 1.00 ppm) of thiamethoxam. Results concluded that M. anisopliae integrated with DE and thiamethoxam provides more effective control of stored grain insect pests.

Exploiting silver nanoparticles with PMAA against aedes aegypti larvae development: potential larvicidal activity

NASA Astrophysics Data System (ADS)

Carvalho, Mariana T.; de Santana, Gisele S.; de Andrade, Audrey N.; Cabral, Amanda; da Silva Rosa-Leão, Nairane; de Melo-Santos, Maria Alice V.; Gomes, Anderson S. L.

2018-02-01

Aedes aegypti is one of the mosquito species with major epidemiological importance in Brazil, involved with the transmission of the arboviruses such as Dengue, Chikungunya and Zika. Since the mosquito is well adapted to the urban environments, where there are large amounts of breeding sites for larvae and pupae, its control has become increasingly difficult. Since 1996, the usual control is made by using chemical larvicides, but the continued use of some of these compounds has led to the selection of A. aegypti resistant populations. Therefore, the search for new insecticidal substances is necessary to guarantee the control of this specie. Our goal is to establish a new larvicide with high toxicity without the drawback of resistance. For this, we developed a low-cost green synthesized silver nanoparticles with a poly(methacrylic acid) outer layer, catalyzed with ultra violet light. We tested nanoparticles samples produced from different batches in laboratory bioassays against fourth-instar larvae. The results showed a desired toxic activity, presenting 10% to 100% of mortalities in concentrations ranging from 0.01 to 1.1 ppm, and from the bioassay we have obtained LC50 = 0.027 ppm and LC90 = 0.044 ppm, after 24 hours of exposure. Imaging the threated larvae by optical microscopy and optical coherence tomography helped to clarify the potential larvae death mechanism. These results associated with the simplicity and low cost of production of these silver nanoparticles, reveal their great potential for the development of products to control of A. aegypti larvae.

Repellent activity of desiccant dusts and conidia of the entomopathogenic fungus Beauveria bassiana when tested against poultry red mites (Dermanyssus gallinae) in laboratory experiments.

PubMed

Kilpinen, Ole; Steenberg, Tove

2016-11-01

Desiccant dusts and entomopathogenic fungi have previously been found to hold potential against the poultry red mite, which is an important pest in egg production and notoriously difficult to control. Both control agents may cause repellence in other arthropods and potentially also influence control levels adversely when used against the poultry red mite. Five desiccant dust products with good efficacy against the poultry red mite Dermanyssus gallinae caused avoidance behavior in mites when tested in bioassays. The repellent activity was correlated with efficacy, which was found to depend on both dose and relative humidity (RH). However, one desiccant dust was significantly less repellent compared to other dusts with similar levels of efficacy. Further, dry conidia of the fungus Beauveria bassiana were also shown to be repellent to poultry red mites, both when applied on its own and when admixed with a low dose of the desiccant dust Diamol. The pick-up of desiccant dust particles and fungus conidia from treated surfaces by mites did not differ depending on RH, whereas the overall efficacy of the two control agents were significantly higher at 75 than at 85 % RH. In addition, the combined effect of the two substances was synergistic when tested in a bioassay where mites could choose whether to cross a treated surface. This is the first time a member of Acari has been shown to be repelled by desiccant dusts and by conidia of an entomopathogenic fungus.

Genomic investigation of year-long and multigenerational exposures of fathead minnow to the munitions compound RDX.

PubMed

Gust, Kurt A; Brasfield, Sandra M; Stanley, Jacob K; Wilbanks, Mitchell S; Chappell, Pornsawan; Perkins, Edward J; Lotufo, Guilherme R; Lance, Richard F

2011-08-01

We assessed the impacts of exposure to an environmentally representative concentration (0.83 mg/L) of the explosive cyclotrimethylenetrinitramine (RDX) on fathead minnows (Pimephales promelas) in one-year and multigenerational bioassays. In the one-year bioassay, impacts were assessed by statistical comparisons of females from breeding groups reared in control or RDX-exposure conditions. The RDX had no significant effect on gonadosomatic index or condition factor assayed at 1 d and at one, three, six, nine, and 12 months. The liver-somatic index was significantly increased versus controls only at the 12-month timepoint. RDX had no significant effect on live-prey capture rates, egg production, or fertilization. RDX caused minimal differential-transcript expression with no consistent discernable effect on gene-functional categories for either brain or liver tissues in the one-year exposure. In the multigenerational assay, the effects of acute (96 h) exposure to RDX were compared in fish reared to the F(2) generation in either control or RDX-exposure conditions. Enrichment of gene functions including neuroexcitatory glutamate metabolism, sensory signaling, and neurological development were observed comparing control-reared and RDX-reared fish. Our results indicated that exposure to RDX at a concentration representing the highest levels observed in the environment (0.83 mg/L) had limited impacts on genomic, individual, and population-level endpoints in fathead minnows in a one-year exposure. However, multigenerational exposures altered transcript expression related to neural development and function. Environ. Copyright © 2011 SETAC.

Genotoxicity of leachates from a landfill using three bioassays.

PubMed

Cabrera, G L; Rodriguez, D M

1999-05-19

In the city of Queretaro, around 500 tons of solid wastes are produced everyday and are deposited in a landfill. This is the result of social and economic activities of human beings or from their normal physiological functions. As a result of rain, leachates are produced, which, if not handled and treated correctly, may pollute the underground water. Among the bioassays developed for the detection of mutagenicity in environmental pollutants, plant systems have been proven to be sensitive, cheap, and effective. The purpose of this study was to determine the presence of genotoxic agents in the leachates of the landfill of the city using three bioassays: Tradescantia-micronucleus (Trad-MCN), Tradescantia stamen hair mutations (Trad-SHM) and Allium root anaphase aberrations (AL-RAA) and make a comparison of the results in the three assays. Leachates were sampled during both the dry and rainy seasons. Plant cuttings of Tradescantia or the roots of Allium were treated by submerging them in the leachates. Three replicates of each sample were analyzed in each of the three bioassays. As expected the samples of leachates collected during the dry season showed a higher genotoxicity than those collected during the rainy season. In conclusion, there are substances present in the leachates capable of inducing genotoxicity in the plant assays. On the other hand, the plant assays showed different degrees of sensitivity: the more sensitive was the Trad-MCN bioassay and the less sensitive the Trad-SHM assay. Therefore, when analyzing environmental pollutants it is recommended to use a battery of bioassays. Copyright 1999 Elsevier Science B.V.

Integrating bioassays and analytical chemistry as an improved approach to support safety assessment of food contact materials.

PubMed

Veyrand, Julien; Marin-Kuan, Maricel; Bezencon, Claudine; Frank, Nancy; Guérin, Violaine; Koster, Sander; Latado, Hélia; Mollergues, Julie; Patin, Amaury; Piguet, Dominique; Serrant, Patrick; Varela, Jesus; Schilter, Benoît

2017-10-01

Food contact materials (FCM) contain chemicals which can migrate into food and result in human exposure. Although it is mandatory to ensure that migration does not endanger human health, there is still no consensus on how to pragmatically assess the safety of FCM since traditional approaches would require extensive toxicological and analytical testing which are expensive and time consuming. Recently, the combination of bioassays, analytical chemistry and risk assessment has been promoted as a new paradigm to identify toxicologically relevant molecules and address safety issues. However, there has been debate on the actual value of bioassays in that framework. In the present work, a FCM anticipated to release the endocrine active chemical 4-nonyphenol (4NP) was used as a model. In a migration study, the leaching of 4NP was confirmed by LC-MS/MS and GC-MS. This was correlated with an increase in both estrogenic and anti-androgenic activities as measured with bioassays. A standard risk assessment indicated that according to the food intake scenario applied, the level of 4NP measured was lower, close or slightly above the acceptable daily intake. Altogether these results show that bioassays could reveal the presence of an endocrine active chemical in a real-case FCM migration study. The levels reported were relevant for safety assessment. In addition, this work also highlighted that bioactivity measured in migrate does not necessarily represent a safety issue. In conclusion, together with analytics, bioassays contribute to identify toxicologically relevant molecules leaching from FCM and enable improved safety assessment.

The use of genetically modified mice in cancer risk assessment: challenges and limitations.

PubMed

Eastmond, David A; Vulimiri, Suryanarayana V; French, John E; Sonawane, Babasaheb

2013-09-01

The use of genetically modified (GM) mice to assess carcinogenicity is playing an increasingly important role in the safety evaluation of chemicals. While progress has been made in developing and evaluating mouse models such as the Trp53⁺/⁻, Tg.AC and the rasH2, the suitability of these models as replacements for the conventional rodent cancer bioassay and for assessing human health risks remains uncertain. The objective of this research was to evaluate the use of accelerated cancer bioassays with GM mice for assessing the potential health risks associated with exposure to carcinogenic agents. We compared the published results from the GM bioassays to those obtained in the National Toxicology Program's conventional chronic mouse bioassay for their potential use in risk assessment. Our analysis indicates that the GM models are less efficient in detecting carcinogenic agents but more consistent in identifying non-carcinogenic agents. We identified several issues of concern related to the design of the accelerated bioassays (e.g., sample size, study duration, genetic stability and reproducibility) as well as pathway-dependency of effects, and different carcinogenic mechanisms operable in GM and non-GM mice. The use of the GM models for dose-response assessment is particularly problematic as these models are, at times, much more or less sensitive than the conventional rodent cancer bioassays. Thus, the existing GM mouse models may be useful for hazard identification, but will be of limited use for dose-response assessment. Hence, caution should be exercised when using GM mouse models to assess the carcinogenic risks of chemicals.

The use of genetically modified mice in cancer risk assessment: Challenges and limitations*

PubMed Central

Eastmond, David A.; Vulimiri, Suryanarayana V.; French, John E.; Sonawane, Babasaheb

2015-01-01

The use of genetically modified (GM) mice to assess carcinogenicity is playing an increasingly important role in the safety evaluation of chemicals. While progress has been made in developing and evaluating mouse models such as the Trp53+/−, Tg.AC and the rasH2, the suitability of these models as replacements for the conventional rodent cancer bioassay and for assessing human health risks remains uncertain. The objective of this research was to evaluate the use of accelerated cancer bioassays with GM mice for assessing the potential health risks associated with exposure to carcinogenic agents. We compared the published results from the GM bioassays to those obtained in the National Toxicology Program’s conventional chronic mouse bioassay for their potential use in risk assessment. Our analysis indicates that the GM models are less efficient in detecting carcinogenic agents but more consistent in identifying non-carcinogenic agents. We identified several issues of concern related to the design of the accelerated bioassays (e.g., sample size, study duration, genetic stability and reproducibility) as well as pathway-dependency of effects, and different carcinogenic mechanisms operable in GM and non-GM mice. The use of the GM models for dose-response assessment is particularly problematic as these models are, at times, much more or less sensitive than the conventional rodent cancer bioassays. Thus, the existing GM mouse models may be useful for hazard identification, but will be of limited use for dose-response assessment. Hence, caution should be exercised when using GM mouse models to assess the carcinogenic risks of chemicals. PMID:23985072

Do we really need in-situ bioassays?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Salazar, M.H.; Salazar, S.M.

1995-12-31

In-situ bioassays are needed to validate the results from laboratory testing and to understand biological interactions. Standard laboratory protocols provide reproducible test results, and the precision of those tests can be mathematically defined. Significant correlations between toxic substances and levels of response (bioaccumulation and bioeffects) have also been demonstrated with natural field populations and suggest that the laboratory results can accurately predict field responses. An equal number of studies have shown a lack of correlation between laboratory bioassay results and responses of natural field populations. The best way to validate laboratory results is with manipulative field testing; i.e., in-situ bioassaysmore » with caged organisms. Bioaccumulation in transplanted bivalves has probably been the most frequently used form of an in-situ bioassay. The authors have refined those methods to include synoptic measurements of bioaccumulation and growth. Growth provides an easily-measured bioeffects endpoint and a means of calibrating bioaccumulation. Emphasis has been on minimizing the size range of test animals, repetitive measurements of individuals and standardization of test protocols for a variety of applications. They are now attempting to standardize criteria for accepting and interpreting data in the same way that laboratory bioassays have been standardized. Others have developed methods for in-situ bioassays using eggs, larvae, unicellular organisms, crustaceans, benthic invertebrates, bivalves, and fish. In the final analysis, the in-situ approach could be considered as an exposure system where any clinical measurements are possible. The most powerful approach would be to use the same species in laboratory and field experiments with the same endpoints.« less

The usefulness of a sediment bioassay with the gastropod Nassarius reticulatus in tributyltin monitoring programs.

PubMed

Laranjeiro, Filipe; Pérez, Sara; Navarro, Patricia; Carrero, José Antonio; Beiras, Ricardo

2015-11-01

Despite the use of tributyltin (TBT) had been banned worldwide in 2008 there is still evidence of its deleterious presence in environment. We evaluate the usefulness of a 28days sediment bioassay with Nassarius reticulatus females to monitor TBT pollution, using imposex as endpoint. In addition, butyltins were determined in sediments and tissues, and, whenever posible, imposex was assessed in native N. reticulatus at the same sites where sediments were sampled. In the bioassay, a significant increase in imposex parameters was obtained with three sediments (Vi2, Vi3, and Vi4). No correlation was found between this and TBT concentrations in sediment although good correlations were obtained for TBT in tissues, putting in evidence TBT bioavailability in sediment. A significant decrease in imposex from 2008 to 2013 in native snails was only observed at sites that did not cause any effect in the bioassay. In contrast, imposex levels in 2013 were kept as high as 2008 in one of the sites where a significant imposex increase in the bioassay was observed. The bioassay proves thus to be a practical and ecological relevant tool, as: (i) it can be conducted in sites with no native populations of snails, (ii) it provides early identification of polluted sites, anticipating future imposex levels or early identification of recovering, and (iii) it yields information on the bioavailable fraction of the TBT in the sediment. Therefore, this tool can be of extreme usefulness under the scope of recent European legislative frameworks. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of wastewater and recycled water quality: a comparison of lines of evidence from in vitro, in vivo and chemical analyses.

PubMed

Leusch, Frederic D L; Khan, Stuart J; Gagnon, M Monique; Quayle, Pam; Trinh, Trang; Coleman, Heather; Rawson, Christopher; Chapman, Heather F; Blair, Palenque; Nice, Helen; Reitsema, Tarren

2014-03-01

We investigated water quality at an advanced water reclamation plant and three conventional wastewater treatment plants using an "ecotoxicity toolbox" consisting of three complementary analyses (chemical analysis, in vitro bioanalysis and in situ biological monitoring), with a focus on endocrine disruption. The in vitro bioassays were chosen to provide an appropriately wide coverage of biological effects relevant to managed aquifer recharge and environmental discharge of treated wastewater, and included bioassays for bacterial toxicity (Microtox), genotoxicity (umuC), photosynthesis inhibition (Max-I-PAM) and endocrine effects (E-SCREEN and AR-CALUX). Chemical analysis of hormones and pesticides using LCMSMS was performed in parallel to correlate standard analytical methods with the in vitro assessment. For two plants with surface water discharge into open drains, further field work was carried out to examine in situ effects using mosquitofish (Gambusia holbrooki) as a bioindicator species for possible endocrine effects. The results show considerable cytotoxicity, phytotoxicity, estrogenicity and androgenicity in raw sewage, all of which were significantly reduced by conventional wastewater treatment. No biological response was detected to RO water, suggesting that reverse osmosis is a significant barrier to biologically active compounds. Chemical analysis and in situ monitoring revealed trends consistent with the in vitro results: chemical analysis confirmed the removal trends observed by the bioanalytical tools, and in situ sampling did not reveal any evidence of endocrine disruption specifically due to discharge of treated wastewater (although other sources may be present). Biomarkers of exposure (in vitro) and effect (in vivo or in situ) are complementary and together provide information with a high level of ecological relevance. This study illustrates the utility of combining multiple lines of evidence in the assessment of water quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Air quality in the Olona Valley and in vitro human health effects.

PubMed

Teoldi, Federico; Lodi, Marco; Benfenati, Emilio; Colombo, Andrea; Baderna, Diego

2017-02-01

Air quality is a major point in current health policies in force globally to protect human health and ecosystems. Cardiovascular and lung diseases are the pathologies most commonly associated with air pollution and it has been estimated that exposure to particulate matters and ground-level ozone and nitric oxides caused >500.000 premature deaths in Europe. Although air quality was generally improved in the recent years, further efforts are required to reduce the impact of air pollution on humans. The present study applied a multidisciplinary approach to estimate the adverse effects on the health of the inhabitants of the Olona Valley in the north of Italy. Chemical analyses quantified the air levels of metals, dioxins, PCBs, PAHs and some macropollutants, including total, fine and coarse airborne particles. These results were used as input for the health risk assessment and in vitro bioassays were used to evaluate possible adverse effects on the respiratory tract due to the organic pollutants adsorbed on the airborne particulate matter. Critical alerts were identified from the air characterization and from the chemical-based risk assessment in view of the levels of arsenic, nickel, benzene, fine and coarse particulate matters found in the investigated zone, which can induce severe adverse effects on human health. These findings were confirmed by bioassays with A549 and BEAS-2B cells. We also used the cell transformation assay with BALB/c 3T3 cells to assess the carcinogenicity of the organic extracts of collected particles as an innovative tool to establish the possible chronic effects of inhaled pollutants. No significant changes in morphological transformation were found suggesting that, although the extracts contain compounds with proven carcinogenic potential, in our experimental conditions the levels of these pollutants were too low to induce carcinogenesis as resulted also by the chemical-based risk assessment. Copyright © 2016 Elsevier B.V. All rights reserved.

G119S ace-1 mutation conferring insecticide resistance detected in the Culex pipiens complex in Morocco.

PubMed

Bkhache, Meriem; Tmimi, Fatim-Zohra; Charafeddine, Omar; Benabdelkrim Filali, Oumama; Lemrani, Meryem; Labbé, Pierrick; Sarih, M'hammed

2018-06-09

Arboviruses are controlled through insecticide control of their mosquito vector. However, inconsiderate use of insecticides often results in the selection of resistance in treated populations, so that monitoring is required to optimize their usage. Here, Culex pipiens (West Nile and Rift Valley Fever virus vector) specimens were collected from four Moroccan cities. Levels of susceptibility to the organophosphate (OP) insecticide malathion were assessed using WHO-recommended bioassays. Individual mosquitoes were tested for the presence of the G119S mutation in the ace-1 gene, the main OP-target resistance mutation. Bioassays showed that mosquitoes from Mohammedia were significantly more resistant to malathion than those from Marrakech. Analyzing the ace-1 genotypes in dead and surviving individuals suggested that other resistance mechanisms may be present in Mohammedia. The ace-1 resistance allele frequencies were relatively moderate (<0.4). Their analyses in three Moroccan cities (Tangier, Casablanca and Marrakech) however showed disparities between two coexisting Cx. pipiens forms and revealed that the G119S mutation tends to be more frequent in urban than in rural collections sites. These findings provide a reference assessment of OP resistance in Morocco and should help the health authorities to develop informed and sustainable vector control programs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Influence of Temperature and Relative Humidity on the Insecticidal Efficacy of Metarhizium anisopliae against Larvae of Ephestia kuehniella (Lepidoptera: Pyralidae) on Wheat.

PubMed

Athanassiou, Christos G; Kavallieratos, Nickolas G; Rumbos, Christos I; Kontodimas, Demetrius C

2017-01-01

A series of laboratory bioassays were conducted for the evaluation of the insecticidal efficacy of an isolate of Metarhizium anisopliae (Metschnikoff) Sorokin (Ascomycota: Hypocreales) against larvae of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), under various temperature-relative humidity (r.h.) conditions. The fungus was applied at four doses (0, 8 × 106, 8 × 108, and 8 × 1010 conidia ml-1) on wheat and insect mortality was assessed after exposure of 1, 2, 7, and 14 d. Bioassays were conducted at three temperatures (20, 25, and 30 °C) and two r.h. levels (55 and 75%). Although complete control was not achieved in any case, the fungus provided a considerable level of insect control. Mortality of E. kuehniella larvae on wheat treated with M. anisopliae ranged between 41.1 and 93.3% after 14 d of exposure, whereas the respective mortality levels in control dishes never exceeded 28.3%. The increase of temperature resulted in most cases to higher efficacy, indicating that temperature is an important factor for the performance of the fungus. In contrast, in most cases r.h. did not significantly affect the efficacy of the fungus, at least for the humidity levels tested. © The Author 2017. Published by Oxford University Press on behalf of the Entomological Society of America.

CAS role in the brain apoptosis of Bufo arenarum induced by cypermethrin.

PubMed

Izaguirre, M F; Vergara, M N; Casco, V H

2006-08-01

CAS might have a key role in the apoptosis induced by toxins, acting as anti-apoptotic factor, stimulating the cellular proliferation and the cell contact stabilization. To start to elucidate their role in the brain apoptosis of Bufo arenarum induced by cypermethrin (CY), the expression patterns of CAS and several cell adhesion molecules (CAMs) were established. Bufo arenarum tadpoles of the control and acute bioassay survival at different doses (39, 156, 625 and 2,500 microg CY/L) and times (24, 48, 72 and 96 h) of CY treatment were fixed in Carnoy, embedded in paraffin and sectioned. CAS and CAMs expression was determined by immunofluorescence and immunohistochemistry, respectively. When the bioassay starts, CAS increases suggesting a proliferative or regenerative effect, but decreases when the doses and/or the biocide exposure time increases, suggesting compromise of the cellular cycle control and trigger of an apoptotic wave. However, these neurotoxic mechanisms should not involve degradation of N-cadherin and alpha-catenin, in contrast of beta-catenin and axonal N-CAM180, at least in the initial apoptotic phase. Additionally, an adhesion compensatory mechanism by N-CAM180 is observed in the neuron cell body. These results suggest a dual role of CAS in the cellular cycle control during the CY-induced apoptosis: induction of cell proliferation and stabilization of the cell-cell junctions by modulating CAMs expression.

Toxicity to and egg-laying avoidance of Drosophila suzukii (Diptera: Drosophilidae) caused by an old alternative inorganic insecticide preparation.

PubMed

Andreazza, Felipe; Vacacela Ajila, Henry E; Haddi, Khalid; Colares, Felipe; Pallini, Angelo; Oliveira, Eugênio E

2018-04-01

The application of synthetic insecticides remains the most used tool for the management of spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). However, management of this pest in the organic production of soft-skinned fruits is a complex task due to the restricted number of registered products. Here, we assess the toxicity of lime sulfur and evaluate whether lime sulfur-treated strawberry plants affected the oviposition and development of D. suzukii. Lime sulfur exhibited adequate toxicity to D. suzukii (LC 50 = 26.6 mL L -1 ) without phytotoxicity to strawberry plants. When D. suzukii females were exposed to lime sulfur-treated plants in no-choice bioassays, oviposition was significantly (t-test, P < 0.05) reduced compared with that on untreated plants. In free-choice bioassays, D. suzukii females laid significantly (paired t-test, P < 0.05) more eggs on untreated plants. Furthermore, in the free-choice bioassays, immature development was slower for adults that originated from eggs laid on lime sulfur-treated plants than from those laid on untreated plants. Lime sulfur showed adequate control and, therefore, has potential for use as a management tool against D. suzukii infestations in organic production systems. This old, alternative insecticide preparation not only caused adult fly mortality, but also reduced the number of eggs laid on lime sulfur-treated plants. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Ecotoxicological bioassays of sediment leachates in a river bed flanked by decommissioned pesticide plants in Nantong City, East China.

PubMed

Zhou, Yan; Wang, Fenghe; Wan, Jinzhong; He, Jian; Li, Qun; Qiang Chen; Gao, Jay; Lin, Yusuo; Zhang, Shengtian

2017-03-01

Traditionally, the toxicity of river contaminants is analyzed chemically or physically through river bed sediments. The biotoxicity of polluted sediment leachates has not caught our attention. This study aims to overcome this deficiency through a battery of biotests which were conducted to monitor comprehensive toxicity of sediment leachates for the Yaogang River in East Jiangsu Province of China, which is in close proximity to former pesticide plants. The general physical and chemical parameters of major pollutants were analyzed from river bed sediments collected at five strategic locations. The ecotoxicity analyses undertaken include overall fish (adult zebrafish) acute toxicity, luminescent bacteria (Vibrio fischeri) bioassay, and zebrafish embryo toxicity assay. Compared with the control group, sediment leachates increased the lethality, inhibited the embryos hatching and induced development abnormalities of zebrafish embryos, and inhibited the luminescence of V. fischeri. The results show that sediment leachates may assume various toxic effects, depending on the test organism. This diverse toxicity to aquatic organisms reflects their different sensitivity to sediment leachates. It is found clearly that V. fischeri was the organism which was characterized by the highest sensitivity to the sediment leachates. The complicated toxicity of leachates was not caused by one single factor but by multiple pollutants together. This indicates the need of estimations of sediment leachate not only taking into account chemical detection but also of applying the biotests to the problem. Thus, multigroup bioassays are necessary to realistically evaluate river ecological risks imposed by leachates.

Dioxin-like Compounds in Lake Fish Species: Evaluation by DR-CALUX Bioassay.

PubMed

Sciuto, S; Prearo, M; Desiato, R; Bulfon, C; Burioli, E A V; Esposito, G; Guglielmetti, C; Dell'atti, L; Ru, G; Volpatti, D; Acutis, P L; Martucci, F

2018-05-01

Fish consumption is the principal source of intake of organochlorinated compounds in humans. Compared with other types of foods of animal origin, fish contain the highest levels of polychlorinated biphenyls (PCBs), polychlorinated dibenzo- p-dioxins, and polychlorinated dibenzofurans, all of which are classified as highly toxic organochlorine compounds. Currently, lakes and fish farms in northern Italy are not regularly monitored for PCBs and dioxins in areas contaminated by industrial sources, partially because of the high costs of traditional analytical methods that limit the number of samples to be analyzed. The DR-CALUX cell bioassay is based on the uptake of the cellular aryl hydrocarbon receptor (AhR) for dioxins and dioxin-like compounds. The aim of this study was to assess the levels of dioxins and dioxin-like PCB contamination in Lake Maggiore and Lake Como, two lakes in northwestern Italy, and in nearby areas. The levels were quantified using the cell bioassay DR-CALUX and reference controls in two wild fish species, perch ( Perca fluviatilis) and roach ( Rutilus rutilus), and in a farmed species, rainbow trout ( Oncorhynchus mykiss). Tissue samples collected from the farmed rainbow trout were also submitted to immunohistochemical analysis of CYP1A expression as a marker for environmental pollutant-induced liver damage. The levels of dioxins, furans, and dioxin-like PCBs were all below the maximum levels and action limits set by European Union Regulation, suggesting no risk for human health associated with the consumption of the fish species caught or farmed in these areas.

Dissolved organic nitrogen in urban streams: Biodegradability and molecular composition studies.

PubMed

Lusk, Mary G; Toor, Gurpal S

2016-06-01

A portion of the dissolved organic nitrogen (DON) is biodegradable in water bodies, yet our knowledge of the molecular composition and controls on biological reactivity of DON is limited. Our objective was to investigate the biodegradability and molecular composition of DON in streams that drain a gradient of 19-83% urban land use. Weekly sampling over 21 weeks suggested no significant relationship between urban land use and DON concentration. We then selected two streams that drain 28% and 83% urban land use to determine the biodegradability and molecular composition of the DON by coupling 5-day bioassay experiments with high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Both urban streams contained a wide range of N-bearing biomolecular formulas and had >80% DON in lignin-like compounds, with only 5-7% labile DON. The labile DON consisted mostly of lipid-and protein-like structures with high H/C and low O/C values. Comparison of reactive formulas and formed counterparts during the bioassay experiments indicated a shift toward more oxygenated and less saturated N-bearing DON formulas due to the microbial degradation. Although there was a little net removal (5-7%) of organic-bound N over the 5-day bioassay, there was some change to the carbon skeleton of DON compounds. These results suggest that DON in urban streams contains a complex mixture of compounds such as lipids, proteins, and lignins of variable chemical structures and biodegradability. Copyright © 2016 Elsevier Ltd. All rights reserved.

A novel bioassay to evaluate the potential of Beauveria bassiana strain NI8 and the Insect growth regulator novaluron against Lygus lineolaris on a non-autoclaved solid artificial diet

USDA-ARS?s Scientific Manuscript database

The entomopathogenic fungus Beauveria bassiana and the insect growth regulator novaluron are potential candidates for the control of Lygus lineolaris. Efforts are being made for their use in the Mississippi Delta. B. bassiana and novaluron highly affected TPB survival when they were applied directly...

Evaluating Pyemotes dryas (Vitzthum 1923)(Acari: Pyemotidae) as a parasite of the southern pine beetle

Treesearch

John C. Moser; B. Kielczewski; J. Wisniewski; S. Balazy

1978-01-01

Populations of Pyemotes dryas (Vitzthum 1923) from Poland were bioassayed for potential use in the biological control of the southern pine beetle in the United States. The mite apparently rides and attacks a wide range of European bark beetles that attack conifers and readily consumes brood of the southern pine beetle. However, it is not phoretic on...

Long-term trends in Anopheles gambiae insecticide resistance in Côte d'Ivoire.

PubMed

Edi, Constant A V; Koudou, Benjamin G; Bellai, Louise; Adja, Akre M; Chouaibou, Mouhamadou; Bonfoh, Bassirou; Barry, Sarah J E; Johnson, Paul C D; Müller, Pie; Dongus, Stefan; N'Goran, Eliezer K; Ranson, Hilary; Weetman, David

2014-11-28

Malaria control is heavily dependent on the use of insecticides that target adult mosquito vectors via insecticide treated nets (ITNs) or indoor residual spraying (IRS). Four classes of insecticide are approved for IRS but only pyrethroids are available for ITNs. The rapid rise in insecticide resistance in African malaria vectors has raised alarms about the sustainability of existing malaria control activities. This problem might be particularly acute in Côte d'Ivoire where resistance to all four insecticide classes has recently been recorded. Here we investigate temporal trends in insecticide resistance across the ecological zones of Côte d'Ivoire to determine whether apparent pan-African patterns of increasing resistance are detectable and consistent across insecticides and areas. We combined data on insecticide resistance from a literature review, and bioassays conducted on field-caught Anopheles gambiae mosquitoes for the four WHO-approved insecticide classes for ITN/IRS. The data were then mapped using Geographical Information Systems (GIS) and the IR mapper tool to provide spatial and temporal distribution data on insecticide resistance in An. gambiae sensu lato from Côte d'Ivoire between 1993 and 2014. Bioassay mortality decreased over time for all insecticide classes, though with significant spatiotemporal variation, such that stronger declines were observed in the southern ecological zone for DDT and pyrethroids than in the central zone, but with an apparently opposite effect for the carbamate and organophosphate. Variation in relative abundance of the molecular forms, coupled with dramatic increase in kdr 1014F frequency in M forms (An. coluzzii) seems likely to be a contributory factor to these patterns. Although records of resistance across insecticide classes have become more common, the number of classes tested in studies has also increased, precluding a conclusion that multiple resistance has also increased. Our analyses attempted synthesis of 22 years of bioassay data from Côte d'Ivoire, and despite a number of caveats and potentially confounding variables, suggest significant but spatially-variable temporal trends in insecticide resistance. In the light of such spatio-temporal dynamics, regular, systematic and spatially-expanded monitoring is warranted to provide accurate information on insecticide resistance for control programme management.

[Neonatal hyperthyroidism in a premature infant born to a mother with Grave's disease].

PubMed

Nicaise, C; Gire, C; Brémond, V; Minodier, P; Soula, F; d'Ercole, C; Palix, C

2000-05-01

Neonatal thyrotoxicosis is most commonly due to transplacental transfer of maternal thyroid-stimulating hormone receptor antibodies (TRAb). Bioassay of thyrotropin receptor antibodies may help to determine the risk for neonatal hyperthyroidism. Thyrotoxicosis developed in a premature infant born to a mother with Graves' disease, with a low level of TRAb by bioassay. The infant was treated with carbimazole for two months, until TRAb had disappeared. Bioassay TRAb is not always reliable for predicting the development of neonatal hyperthyroidism in infants born to mothers with Graves' disease. Thyroid function should be measured in all these neonates.

Evaluation of Short-Term Bioassays to Predict Functional Impairment. Development of Cardiovascular Bioassays in Laboratory Animals/Directory of Institutions/Individuals.

DTIC Science & Technology

1980-10-01

r AD-VA~ 207 MITRE CORP MCLEAN VA METREK DIV F/A 6 /20EVALUATION OF SNORT-TERM BIOASSAYS TO PREDICT FUNCTIONAL IMPAIR--ETC(U) OCT Al R THOMAS...Dolley Madison Boulevard ColMcLean, Virginia 22102 S 6 1981O OCT 1u Contracting Officer’s Technical Representative: D Mary C. Henry, Ph.D. US ARMY MEDICAL...GV CESO O .RCPETSCTLGNME A EUL midsAŕ ,yALUATION OF ,11ORT-ER IOA SAYS 5 TaWr"W -T REDICT FUNCTIONAL LPIPNXEN Fiavelor WV C 1 , C rdiovascular

Jack Healy Remembers - Anecdotal Evidence for the Origin of the Approximate 24-hour Urine Sampling Protocol Used for Worker Bioassay Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.

2008-10-01

The origin of the approximate 24-hour urine sampling protocol used at Hanford for routine bioassay is attributed to an informal study done in the mid-1940s. While the actual data were never published and have been lost, anecdotal recollections by staff involved in the initial bioassay program design and administration suggest that the sampling protocol had a solid scientific basis. Numerous alternate methods for normalizing partial day samples to represent a total 24-hour collection have since been proposed and used, but no one method is obviously preferred.

Colloidal crystal beads composed of core-shell particles for multiplex bioassay.

PubMed

Xu, Hua; Zhu, Cun; Zhao, Yuanjin; Zhao, Xiangwei; Hu, Jing; Gu, Zhongze

2009-04-01

A convenient method was developed to fabricate colloidal crystal beads (CCBs) with tough mechanical strength, which was used as encoded carriers for multiplex bioassay. The latex particles used for the construction of the CCBs were designed with a rigid core PS and a elastomeric shell poly(MMA/EA/MAA), and were prepared via one-step soap-free emulsion polymerization. The as-above-prepared CCBs were thermo-treated to drive the elastomeric shells of adjacent latex particles joining together. It was found that the coalescence of latex particles can greatly improve the mechanical strength of the CCBs for multiplex bioassay.

The Intersection of CMOS Microsystems and Upconversion Nanoparticles for Luminescence Bioimaging and Bioassays

PubMed Central

Wei, Liping.; Doughan, Samer.; Han, Yi.; DaCosta, Matthew V.; Krull, Ulrich J.; Ho, Derek.

2014-01-01

Organic fluorophores and quantum dots are ubiquitous as contrast agents for bio-imaging and as labels in bioassays to enable the detection of biological targets and processes. Upconversion nanoparticles (UCNPs) offer a different set of opportunities as labels in bioassays and for bioimaging. UCNPs are excited at near-infrared (NIR) wavelengths where biological molecules are optically transparent, and their luminesce in the visible and ultraviolet (UV) wavelength range is suitable for detection using complementary metal-oxide-semiconductor (CMOS) technology. These nanoparticles provide multiple sharp emission bands, long lifetimes, tunable emission, high photostability, and low cytotoxicity, which render them particularly useful for bio-imaging applications and multiplexed bioassays. This paper surveys several key concepts surrounding upconversion nanoparticles and the systems that detect and process the corresponding luminescence signals. The principle of photon upconversion, tuning of emission wavelengths, UCNP bioassays, and UCNP time-resolved techniques are described. Electronic readout systems for signal detection and processing suitable for UCNP luminescence using CMOS technology are discussed. This includes recent progress in miniaturized detectors, integrated spectral sensing, and high-precision time-domain circuits. Emphasis is placed on the physical attributes of UCNPs that map strongly to the technical features that CMOS devices excel in delivering, exploring the interoperability between the two technologies. PMID:25211198

Development and modification of a recombinant cell bioassay to directly detect halogenated and polycyclic aromatic hydrocarbons in serum.

PubMed

Ziccardi, M H; Gardner, I A; Denison, M S

2000-03-01

Polycyclic and halogenated aromatic hydrocarbons (PAHs/HAHs) are a diverse group of widespread and persistent environmental contaminants that can cause a variety of detrimental effects in vertebrates. As most available methods to detect these contaminants are expensive, labor and time intensive, and require large amounts of tissue for extraction and analysis, several rapid mechanistically based bioassay systems have been developed to detect these chemicals. Here we describe application and optimization of a recently developed recombinant mouse cell bioassay system that responds to both PAHs and HAHs with the rapid induction of firefly luciferase for the detection of these chemicals in whole serum samples. This chemically activated luciferase expression (CALUX) bioassay has been modified to allow rapid (4-h) and direct analysis of small volumes (25-50 microl) of whole serum in a 96-well microtiter plate format without the need for solvent extraction. This bioassay can detect as little as 10 parts per trillion of the most potent HAH, 2,3,7,8-TCDD, and is also sensitive to other HAHs and PAHs. The use of simple procedures corrects for interplate and intraplate variability and the Ah receptor dependence of the induction response is accounted for by use of the antagonist 4-amino-3-methoxyflavone.

Identification of mammalian cell genotoxins in respirable diesel exhaust particles by bioassay-directed chemical analysis.

PubMed

Oh, Seung-Min; Chung, Kyu-Hyuck

2006-03-01

A bioassay-directed chemical analysis which consists of mammalian cell bioassays (comet assay, CBMN assay and EROD-microbioassay) in conjunction with analytical measurements was performed to identify the most biologically active compounds of the diesel exhaust particulate matters (DEPs) on mutagenic activity. These bioassay systems were suitable to estimate the mammalian genotoxic potentials of pollutants present in low concentrations in limited environmental samples, as is the case with DEPEs. The results from mutagenic assay showed that the aromatic and slightly polar fraction of DEPs induced chromosomal damage and DNA breakage in a non-cytotoxic dose. It was also revealed that indirect-acting mutagens may mainly contribute to the mutagenic effect of aromatic fraction via the enzyme metabolism system. In the aromatic fraction, several indirect-acting mutagenic PAHs such as dibenzo(a,h)anthracene, chrysene, and 1,2-benzanthracene were detected by GC-MS and the complex mixture effect of this fraction was quantified in terms of its biological-TCDD equivalent concentration (bio-TEQ) which was 32.82 bio-TEQ ng/g-DEPs by EROD-microbioassay. Conclusively, we confirmed that indirect-acting mutagens contained in aromatic fraction may be important causatives of the genotoxicity of extracts of DEPs by integrating the results obtained from a mammalian cell bioassay-directed fractionation.

Assessment of dioxin-like activity in ambient air particulate matter using recombinant yeast assays

NASA Astrophysics Data System (ADS)

Olivares, Alba; van Drooge, Barend L.; Pérez Ballesta, Pascual; Grimalt, Joan O.; Piña, Benjamin

2011-01-01

Ectopic activation of the aryl hydrocarbon receptor (AhR), also known as dioxin-like activity, is a major component of the toxicity associated with polycyclic aromatic hydrocarbons (PAH). Filtration of ambient air particulate matter through PM 10 filters followed by chemical determination of PAH concentrations and a yeast-based bioassay (RYA) were combined to evaluate and characterize dioxin-like activity in ambient air. Samples were collected in a semirural area of Northern Italy between September 2008 and February 2009. Total PAH contents ranged between 0.3 ng m -3 and 34 ng m -3 and were in correlation with seasonal variations of meteorological conditions and combustion processes. Dioxin-like activity values in air samples showed an excellent correlation (0.71 < R2 < 0.86) with the observed PAH concentrations and the predicted toxicity equivalents for PAH. This RYA-bioassay reported in the present study provides a simple and low-cost routine control for toxic PAH emissions, even at background air concentration levels.

Three-dimensional spheroid culture targeting versatile tissue bioassays using a PDMS-based hanging drop array.

PubMed

Kuo, Ching-Te; Wang, Jong-Yueh; Lin, Yu-Fen; Wo, Andrew M; Chen, Benjamin P C; Lee, Hsinyu

2017-06-29

Biomaterial-based tissue culture platforms have emerged as useful tools to mimic in vivo physiological microenvironments in experimental cell biology and clinical studies. We describe herein a three-dimensional (3D) tissue culture platform using a polydimethylsiloxane (PDMS)-based hanging drop array (PDMS-HDA) methodology. Multicellular spheroids can be achieved within 24 h and further boosted by incorporating collagen fibrils in PDMS-HDA. In addition, the spheroids generated from different human tumor cells exhibited distinct sensitivities toward drug chemotherapeutic agents and radiation as compared with two-dimensional (2D) cultures that often lack in vivo-like biological insights. We also demonstrated that multicellular spheroids may enable key hallmarks of tissue-based bioassays, including drug screening, tumor dissemination, cell co-culture, and tumor invasion. Taken together, these results offer new opportunities not only to achieve the active control of 3D multicellular spheroids on demand, but also to establish a rapid and cost-effective platform to study anti-cancer therapeutics and tumor microenvironments.

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

PubMed

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.

Musca domestica laboratory susceptibility to three ethnobotanical culinary plants.

PubMed

El Zayyat, Elham A; Soliman, Mohammed I; Elleboudy, Noha A; Ofaa, Shaimaa E

2015-10-01

Throughout history, synanthropic Musca domestica had remained a worldwide problem whenever poor sanitation and bad hygienic conditions exists. Houseflies growing resistance to chemical insecticides are a rising environmental problem that necessitates search for alternatives. Mentha cervina, Ocimum basilicum, and Coriandrum sativum were tested for bioactivity on M. domestica adults and larvae. They are culinary Mediterranean plants. In adulticidal bioassay, using both CDC bottles and fumigation techniques, basil was the most effective extract with LC50 1.074 and 34.996 g/L, respectively. Concerning larvicidal bioassay by fumigation technique, coriander had the highest toxicity index with LC50 29.521 g/L. In both dipping and feeding technique, basil had the highest toxicity with LC50 32.643 and 0.749 g/L, respectively. Basil showed the highest toxicity results in four out of the five models tested followed by coriander then mint; this result highlights the potentiality of basil as a green insecticide in management of flies and opens new insight in the industrialization of basil-based fly control products.

Insecticide susceptibility and vector status of natural populations of Anopheles arabiensis from Sudan.

PubMed

Abdalla, H; Matambo, T S; Koekemoer, L L; Mnzava, A P; Hunt, R H; Coetzee, M

2008-03-01

Species composition, blood meal source, sporozoite infection rate, insecticide resistance and the kdr mutations were investigated in the Anopheles gambiae complex from 13 sentinel sites in central Sudan. Species identification revealed that 89.5% of 960 specimens were A. arabiensis. Of 310 indoor resting females, 88.1% were found to have fed on humans, while 10.6% had fed on bovines. The overall sporozoite infection rate from the five localities tested was 2.3%, ranging from 0 to 5.5%. Insecticide susceptibility bioassay results showed 100% mortality on bendiocarb, 54.6-94.2% on permethrin, 55.4-99.1% on DDT and 76.8-100% on malathion. The kdr analysis by PCR and sequencing revealed the presence of the Leu-Phe mutation in both permethrin and DDT bioassays. There was no significant difference in the frequency of kdr (P>0.05) between dead and surviving specimens. These findings have serious implications for the malaria control programmes in Gezira and Sennar states.

USING BIOASSAYS TO EVALUATE THE PERFORMANCE OF RISK MANAGEMENT TECHNIQUES

EPA Science Inventory

Often, the performance of risk management techniques is evaluated by measuring the concentrations of the chemials of concern before and after risk management effoprts. However, using bioassays and chemical data provides a more robust understanding of the effectiveness of risk man...

Development of Reduced Sediment Volume Test Procedures for the Estuarine Amphipod Leptocheirus plumulosus

EPA Science Inventory

The sediment volume requirements of toxicity and bioaccumulation bioassays affect the cost of the assessment related to field collection, transportation, storage, disposal, and labor associated with organism recovery at bioassay termination. Our objective was to assess four redu...

Monitoring changes in bemisia tabaci susceptibility to neonicotinoid insecticides in Arizona and California

USDA-ARS?s Scientific Manuscript database

Laboratory bioassays were carried out on field-collected and laboratory strains of Bemisia tabaci to evaluate relative toxicities of four neonicotinoid insecticides: acetamiprid, dinotefuran, imidacloprid and thiamethoxam. Susceptibility to all four neonicotinoids in leaf-uptake bioassays varied co...

Assessment of Fungal Growth in Liquid Cultures and Bioassay of Toxic Products.

ERIC Educational Resources Information Center

Isaac, Susan; And Others

1988-01-01

Outlined is a procedure for the assessment of fungal growth under different cultural conditions, together with a demonstration of the toxic nature of exudates released from a fungal pathogen during growth in culture, using a simple bioassay. (Author/CW)

Application of Mode of Action Analysis and Human Relevance Framework

EPA Science Inventory

Animal bioassays have been used for more than a half century to determine whether pesticides, pharmaceuticals, industrial chemicals, and other products might cause health problems in humans. As such, animal bioassays have become the standard for detecting the potential for adver...

USING BIOASSAYS TO EVALUATE THE PERFORMANCE OF EDC RISK MANAGEMENT METHODS

EPA Science Inventory

In Superfund risk management research, the performance of risk management techniques is typically evaluated by measuring "the concentrations of the chemicals of concern before and after risk management efforts. However, using bioassays and chemical data provides a more robust und...

Red clover: An alternative to antibiotic growth promoters?

USDA-ARS?s Scientific Manuscript database

A series of experiments were conducted at the Forage-Animal Production Research Unit to discover a growth-promoting natural product from red clover (Trifolium pratense). Previously published work included a bioassay for antimicrobial activity of phytochemicals. The bioassay was used to discover th...

Controlling the near-field excitation of nano-antennas with phase-change materials.

PubMed

Kao, Tsung Sheng; Chen, Yi Guo; Hong, Ming Hui

2013-01-01

By utilizing the strongly induced plasmon coupling between discrete nano-antennas and quantitatively controlling the crystalline proportions of an underlying Ge2Sb2Te5 (GST) phase-change thin layer, we show that nanoscale light localizations in the immediate proximity of plasmonic nano-antennas can be spatially positioned. Isolated energy hot-spots at a subwavelength scale can be created and adjusted across the landscape of the plasmonic system at a step resolution of λ/20. These findings introduce a new approach for nano-circuitry, bio-assay addressing and imaging applications.

Fate and effects of 2,4,6-trinitrotoluene (TNT) from dumped ammunition in a field study with fish and invertebrates.

PubMed

Ek, Helene; Dave, Göran; Nilsson, Eva; Sturve, Joachim; Birgersson, Göran

2006-08-01

2,4,6-Trinitrotoluene (TNT) is the major explosive ingredient in ammunition dumped into lakes and sea after World War II. The aim of the present field study was to study the fate and effect of TNT and its degradation products from dumped ammunition. Artillery shells were cleaved longitudinally to expose TNT and placed in open boxes filled with sediment, and then placed at the sea bottom. Sediment samples were taken in each box at the start and after 3, 9, 13, 20, 24, 33, and 36 months, and the sediments were tested for toxicity with bioassays using Nitocra spinipes (96 h), Hyalella azteca (96 h), and Daphnia magna (24 and 48 h). The result from the bioassays showed no impact of dumped ammunition on the survival of H. azteca and mobility of D. magna. Bioassays with N. spinipes showed significant differences in toxicity between control boxes and boxes with shells after 9 months and thereafter. The mean mortality (+/- SD) of N. spinipes in boxes with shells was 63 +/- 22%, and the mortality in control boxes was 23 +/- 17%. No continuous increase in sediment toxicity over time was found. After 3 years, cages with European flounder (Platichtys flesus) and blue mussels (Mytilus edulis) were attached to the boxes. The fish were examined for biochemical and physiological effects 8 weeks later. Exposure to ammunition, which had rested on the sea bottom 3 years, caused no significant effects on body indices, hematological variables, and detoxification and antioxidant enzymes activities in the flounder. The sediment, bile, and blood plasma of exposed fish, and hepatopancreas of exposed mussels, contained no detectable levels of TNT and its metabolites. Only minor disappearance of TNT from the shells could be detected by visual inspection on site (by scuba divers). This study suggests that the survival of sensitive benthic organisms, e.g., N. spinipes, might be negatively affected at an ammunition dumping site.

Toxicity of Piper aduncum (Piperaceae) Essential Oil Against Euschistus heros (F.) (Hemiptera: Pentatomidae) and Non-Effect on Egg Parasitoids.

PubMed

Turchen, L M; Piton, L P; Dall'Oglio, E L; Butnariu, A R; Pereira, M J B

2016-10-01

Plant essential oils have been recognized as significant natural resources for insecticides. Herein, we have assessed the toxicity of the essential oil of Piper aduncum (Piperaceae) against Euschistus heros (F.) (Hemiptera: Pentatomidae), a key soybean pest in Neotropical America. In addition, we have assessed its effect on the performance of egg parasitoids. The essential oil was obtained from the leaves of P. aduncum via hydrodistillation. Subsequently, bioassays of the concentration response to eggs (contact and immersion methods), nymphs, and adults (topical application) were conducted, to assess the lethal effects on the stink bug. We also evaluated the performance of parasitism and adult emergence of egg parasitoids, when the host eggs were treated with essential oil. In the egg bioassay, both exposure methods were efficient for unviable eggs (immersion LC 50  = 15.64 mg mL -1 ; contact LC 50  = 21.29 mg mL -1 ), with the highlight on the immersion method. The bioassay with nymphs indicated a higher toxicity of essential oil, with lower concentrations (LC 50  = 11.37 mg mL -1 ) being required to cause the death of insects. For adults, a reduction in survival of insects was observed, and consequently, there was a reduction in the number of individuals in the next generation. Although the essential oil was toxic to E. heros, it exhibited lower toxicity for egg parasitoids, as there was no effect on parasitism and the emergence of wasps. We discuss likely explanations for such selectivity. In summary, we found that the essential oil was promising for the control of E. heros, because it caused deleterious effects at all development stages of the stink bug and had no effect on parasitism and emergence of the egg parasitoids, which suggested compatibility with biological control.

Sensitivity of midge larvae of Chironomus tentans Fabricius (Diptera Chironomidae) to heavy metals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khangarot, B.S.; Ray, P.K.

1989-03-01

The discharge of heavy metals into the natural waters has numerous obvious impacts on physical, chemical and biological parameters of aquatic ecosystem. Bioassay tests are important steps in establishing appropriate water quality criteria and standards for diverse use of ponds, lakes, streams and river waters. Therefore, the acute toxicities of various heavy metals to water flea Daphnia magna, and snail Lymnaea acuminata, and toad tadpoles Bufo mentanostictus have been reported from the authors' laboratory. Chironomid larvae might be particularly useful as indicators of water quality because they are widely distributed in freshwater systems and often from diverse communities within particularmore » habitat. The aim of this study was to determine the acute toxicity of ten heavy metals to the midge larvae Chironomus tentans Fabricius, which forms an important link in aquatic food chain(s).« less

The application of computer image analysis in life sciences and environmental engineering

NASA Astrophysics Data System (ADS)

Mazur, R.; Lewicki, A.; Przybył, K.; Zaborowicz, M.; Koszela, K.; Boniecki, P.; Mueller, W.; Raba, B.

2014-04-01

The main aim of the article was to present research on the application of computer image analysis in Life Science and Environmental Engineering. The authors used different methods of computer image analysis in developing of an innovative biotest in modern biomonitoring of water quality. Created tools were based on live organisms such as bioindicators Lemna minor L. and Hydra vulgaris Pallas as well as computer image analysis method in the assessment of negatives reactions during the exposition of the organisms to selected water toxicants. All of these methods belong to acute toxicity tests and are particularly essential in ecotoxicological assessment of water pollutants. Developed bioassays can be used not only in scientific research but are also applicable in environmental engineering and agriculture in the study of adverse effects on water quality of various compounds used in agriculture and industry.

In Vitro Biologic Activities of the Antimicrobials Triclocarban, Its Analogs, and Triclosan in Bioassay Screens: Receptor-Based Bioassay Screens

PubMed Central

Ahn, Ki Chang; Zhao, Bin; Chen, Jiangang; Cherednichenko, Gennady; Sanmarti, Enio; Denison, Michael S.; Lasley, Bill; Pessah, Isaac N.; Kültz, Dietmar; Chang, Daniel P.Y.; Gee, Shirley J.; Hammock, Bruce D.

2008-01-01

Background Concerns have been raised about the biological and toxicologic effects of the antimicrobials triclocarban (TCC) and triclosan (TCS) in personal care products. Few studies have evaluated their biological activities in mammalian cells to assess their potential for adverse effects. Objectives In this study, we assessed the activity of TCC, its analogs, and TCS in in vitro nuclear-receptor–responsive and calcium signaling bioassays. Materials and methods We determined the biological activities of the compounds in in vitro, cell-based, and nuclear-receptor–responsive bioassays for receptors for aryl hydrocarbon (AhR), estrogen (ER), androgen (AR), and ryanodine (RyR1). Results Some carbanilide compounds, including TCC (1–10 μM), enhanced estradiol (E2)-dependent or testosterone-dependent activation of ER- and AR-responsive gene expression up to 2.5-fold but exhibited little or no agonistic activity alone. Some carbanilides and TCS exhibited weak agonistic and/or antagonistic activity in the AhR-responsive bioassay. TCS exhibited antagonistic activity in both ER- and AR-responsive bioassays. TCS (0.1–10 μM) significantly enhanced the binding of [3H]ryanodine to RyR1 and caused elevation of resting cytosolic [Ca2+] in primary skeletal myotubes, but carbanilides had no effect. Conclusions Carbanilides, including TCC, enhanced hormone-dependent induction of ER- and AR-dependent gene expression but had little agonist activity, suggesting a new mechanism of action of endocrine-disrupting compounds. TCS, structurally similar to noncoplanar ortho-substituted poly-chlorinated biphenyls, exhibited weak AhR activity but interacted with RyR1 and stimulated Ca2+ mobilization. These observations have potential implications for human and animal health. Further investigations are needed into the biological and toxicologic effects of TCC, its analogs, and TCS. PMID:18795164

Effects of wind speed on aerosol spray penetration in adult mosquito bioassay cages.

PubMed

Hoffmann, W Clint; Fritz, Bradley K; Farooq, Muhammad; Cooperband, Miriam F

2008-09-01

Bioassay cages are commonly used to assess efficacy of insecticides against adult mosquitoes in the field. To correlate adult mortality readings to insecticidal efficacy and/or spray application parameters properly, it is important to know how the cage used in the bioassay interacts with the spray cloud containing the applied insecticide. This study compared the size of droplets, wind speed, and amount of spray material penetrating cages and outside of cages in a wind tunnel at different wind speeds. Two bioassay cages, Center for Medical, Agricultural and Veterinary Entomology (CMAVE) and Circle, were evaluated. The screen materials used on these cages reduced the size of droplets, wind speed, and amount of spray material inside the cages as compared to the spray cloud and wind velocity outside of the cages. When the wind speed in the dispersion tunnel was set at 0.6 m/sec (1.3 mph), the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.045 m/sec (0.10 mph) and 0.075 m/sec (0.17 mph), respectively. At air velocities of 2.2 m/sec (4.9 mph) in the dispersion tunnel, the mean wind speed inside of the CMAVE Bioassay Cage and Circle Cage was 0.83 m/sec (1.86 mph) and 0.71 m/sec (1.59 mph), respectively. Consequently, there was a consistent 50-70% reduction of spray material penetrating the cages compared to the spray cloud that approached the cages. These results provide a better understanding of the impact of wind speed, cage design, and construction on ultra-low-volume spray droplets.

The combined use of the PLHC-1 cell line and the recombinant yeast assay to assess the environmental quality of estuarine and coastal sediments.

PubMed

Schnell, Sabine; Olivares, Alba; Piña, Benjamin; Echavarri-Erasun, Beatriz; Lacorte, Silvia; Porte, Cinta

2013-12-15

Sediment contamination poses a potential risk for both ecosystems and human health. Risk assessment is troublesome as sediments contain complex mixtures of toxicants, and traditional chemical analyses can neither provide information about potential hazards to organisms nor identify and measure all present contaminants. This work combines the use of the PLHC-1 cell line and the recombinant yeast assay (RYA) to assess the environmental quality of estuarine and coastal sediments. The application of multiple endpoints (cytotoxicity, generation of oxidative stress, presence of CYP1A inducing agents, micronucleus formation and estrogenicity) revealed that the organic extracts of those sediments affected by industrial activities or collected near harbours and untreated urban discharges showed significant cytotoxicity, micronuclei and CYP1A induction. The study highlights the usefulness of the applied bioassays to identify those sediments that could pose risk to aquatic organisms and that require further action to improve their environmental quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

IN SITU BIOASSAY CHAMBER FOR ASSESSMENT OF SEDIMENT TOXICITY AND BIOACCUMULATION USING BENTHIC INVERTEBRATES

EPA Science Inventory

In this study, we describe the construction of a simple, inexpensive bioassay chamber for testing sediment toxicity (survival and growth) and bioaccumulation under field conditions using the midge Chironomus tentans and the oligochaete Lumbriculus variegatus. The test chamber is ...

An Estuarine Fish Bioassay for Sensitive Biomonitoring of Oil-related Contamination

EPA Science Inventory

An embryonic and larval bioassay using the estuarine fish, Fundulus heteroclitus, was modified for the rapid detection of bioavailable compounds that act through the aryl hydrocarbon receptor (AhR). The early development of fishes is particularly sensitive to AhR agonists, such ...

Comparative susceptibility of bemisia tabaci to imidacloprid in field- and laboratory-based bioassays

USDA-ARS?s Scientific Manuscript database

Bemisia tabaci biotype B is a resistance-prone pest of protected and open agriculture. Systemic uptake bioassays used in resistance monitoring programs have provided important information on susceptibility to neonicotinoid insecticides, but have remained decoupled from field performance. Simultaneou...

Bioassay techniques for detecting root leakage of auxinic herbicides

USDA-ARS?s Scientific Manuscript database

Biological assay (bioassay) techniques are a simple way to determine the presence of herbicides in soil or other potting media. Understanding the fate of herbicides after absorption is important when guidelines for use are developed. Greenhouse studies were conducted with the herbicide aminocyclopyr...

COMPARATIVE POTENCY OF COMPLEX MIXTURES: USE OF SHORT-TERM GENETIC BIOASSAYS IN CANCER RISK ASSESSMENT

EPA Science Inventory

The primary problem regarding the introduction of new energy sources is whether they will alter the mutagenicity, carcinogenicity and potential human cancer risk from combustion emissions. New risk assessment methodologies utilizing data from short-term bioassays, therefore, are ...

STRESS ETHYLENE: A BIOASSAY FOR RHIZOSPHERE-APPLIED PHYTOTOXICANTS

EPA Science Inventory

A bioassay for rhizosphere-applied phytotoxicants was developed and evaluated with a broad range of chemicals. Test substances were applied to the rhizosphere of whole, intact bush bean plants (Phaseolus vulgaris L. cv. Bush Blue Lake 290) grown in a solid support medium and the ...

Scrubchem: Building Bioactivity Datasets from Pubchem Bioassay Data (SOT)

EPA Science Inventory

The PubChem Bioassay database is a non-curated public repository with data from 64 sources, including: ChEMBL, BindingDb, DrugBank, EPA Tox21, NIH Molecular Libraries Screening Program, and various other academic, government, and industrial contributors. Methods for extracting th...

Investigation of animal and algal bioassays for reliable saxitoxin ecotoxicity and cytotoxicity risk evaluation.

PubMed

Perreault, François; Matias, Marcelo Seleme; Melegari, Silvia Pedroso; Pinto, Catia Regina Silva de Carvalho; Creppy, Edmond Ekué; Popovic, Radovan; Matias, William Gerson

2011-05-01

Contamination of water bodies by saxitoxin can result in various toxic effects in aquatic organisms. Saxitoxin contamination has also been shown to be a threat to human health in several reported cases, even resulting in death. In this study, we evaluated the sensitivity of animal (Neuro-2A) and algal (Chlamydomonas reinhardtii) bioassays to saxitoxin effect. Neuro-2A cells were found to be sensitive to saxitoxin, as shown by a 24 h EC50 value of 1.5 nM, which was obtained using a cell viability assay. Conversely, no saxitoxin effect was found in any of the algal biomarkers evaluated, for the concentration range tested (2-128 nM). These results indicate that saxitoxin may induce toxic effects in animal and human populations at concentrations where phytoplankton communities are not affected. Therefore, when evaluating STX risk of toxicity, algal bioassays do not appear to be reliable indicators and should always be conducted in combination with animal bioassays. Copyright © 2011 Elsevier Inc. All rights reserved.

Latex agglutination inhibition card test for gentamicin assay: clinical evaluation and comparison with radioimmunoassay and bioassay.

PubMed Central

Standiford, H C; Bernstein, D; Nipper, H C; Caplan, E; Tatem, B; Hall, J S; Reynolds, J

1981-01-01

Gentamicin levels were determined in 100 serum specimens by a new latex agglutination inhibition card test, a radioimmunoassay (RIA), and a bioassay. Correlation coefficients determined by linear regression analysis demonstrated that the levels obtained by the latex agglutination inhibition card test had a high degree of correlation with the RIA and could be performed much faster and more economically when processing small numbers of specimens. The bioassay had a slightly lower degree of correlation with both the RIA and the latex test and was adversely influenced by concurrently administered antibiotics which could not be eliminated by beta-lactamase. When measuring gentamicin concentrations above 2 micrograms/ml, the coefficient of variation was less than 14% for the latex agglutination assay compared with 15% for the bioassay and 12% for RIA. The latex agglutination inhibition card test is a rapid, accurate, specific, and reproducible method for monitoring gentamicin levels in patients and is particularly applicable for laboratories processing small numbers of specimens. PMID:7247384

Novel bioassay demonstrates attraction of the white potato cyst nematode Globodera pallida (Stone) to non-volatile and volatile host plant cues.

PubMed

Farnier, Kevin; Bengtsson, Marie; Becher, Paul G; Witzell, Johanna; Witzgall, Peter; Manduríc, Sanja

2012-06-01

Potato cyst nematodes (PCNs) are a major pest of solanaceous crops such as potatoes, tomatoes, and eggplants and have been widely studied over the last 30 years, with the majority of earlier studies focusing on the identification of natural hatching factors. As a novel approach, we focused instead on chemicals involved in nematode orientation towards its host plant. A new dual choice sand bioassay was designed to study nematode responses to potato root exudates (PRE). This bioassay, conducted together with a traditional hatching bioassay, showed that biologically active compounds that induce both hatching and attraction of PCNs can be collected by water extraction of incised potato roots. Furthermore, our results demonstrated that PCN also were attracted by potato root volatiles. Further work is needed to fully understand how PCNs use host plant chemical cues to orientate towards hosts. Nevertheless, the simple attraction assay used in this study provides an important tool for the identification of host-emitted attractants.

Current and emerging challenges in toxicopathology: Carcinogenic threshold of phenobarbital and proof of arsenic carcinogenicity using rat medium-term bioassays for carcinogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukushima, Shoji; Morimura, Keiichirou; Wanibuchi, Hideki

2005-09-01

For the last 25 years, Prof. Nobuyuki Ito and his laboratory have focused on the development of liver medium-term bioassay system for detection of carcinogens in F344 rats utilizing glutathione S-transferase placental form (GST-P)-positive foci as an end point marker. In this presentation, the outline and samples of medium-term bioassay systems were described. Furthermore, our data demonstrated the presence of a threshold for the non-genotoxic carcinogen, phenobarbital (PB), and the lack of linearity in the low-dose area of the dose-response curve, providing evidence for hormesis. In addition, the establishment and applications of multiorgan carcinogenicity bioassay (DMBDD model), used for themore » examination of the carcinogenicity of genotoxic and non-genotoxic chemicals, are discussed. Dimethylarsinic acid, one of organic arsenics, was found to be carcinogenic in rat bladder using DMBDD model and carcinogenicity test.« less

In Vitro Androgen Bioassays as a Detection Method for Designer Androgens

PubMed Central

Cooper, Elliot R.; McGrath, Kristine C. Y.; Heather, Alison K.

2013-01-01

Androgens are the class of sex steroids responsible for male sexual characteristics, including increased muscle mass and decreased fat mass. Illicit use of androgen doping can be an attractive option for those looking to enhance sporting performance and/or physical appearance. The use of in vitro bioassays to detect androgens, especially designer or proandrogens, is becoming increasingly important in combating androgen doping associated with nutritional supplements. The nutritional sports supplement market has grown rapidly throughout the past decade. Many of these supplements contain androgens, designer androgens or proandrogens. Many designer or proandrogens cannot be detected by the standard highly-sensitive screening methods such as gas chromatography-mass spectrometry because their chemical structure is unknown. However, in vitro androgen bioassays can detect designer and proandrogens as these assays are not reliant on knowing the chemical structure but instead are based on androgen receptor activation. For these reasons, it may be advantageous to use routine androgen bioassay screening of nutraceutical samples to help curb the increasing problem of androgen doping. PMID:23389345

Methodology for the ecotoxicological evaluation of areas polluted by phosphogypsum wastes.

NASA Astrophysics Data System (ADS)

Martínez-Sanchez, M. J.; Garcia-Lorenzo, M. L.; Perez-Sirvent, C.; Martinez-Lopez, S.; Hernandez-Cordoba, M.; Bech, J.

2012-04-01

In Spain, the production of phosphoric acid, and hence of phosphogypsum, is restricted to a fertilizer industrial site. The residues contain some radionuclides of the U-series and other contaminants. In order to estimate the risk posed by these materials, chemical methods need to be complemented with biological methods. Then, the aim of this study was to develop a battery of bioassays for the ecotoxicological screening of areas polluted by phosphogypsum wastes. Particularly, the toxicity of water samples, sediments and their pore-water extracts was evaluated by using three assays: bacteria, plants and ostracods. The applied bioassays were: the bioluminescence inhibition of Vibrio fischeri in superficial water samples using Microtox® bioassay; the root and shoot elongation inhibition and the mortality of Lepidium sativum, Sorghum saccharatum and Sinapis alba using Phytotoxkit® bioassay; and inhibition of Heterocypris incongruens by way of Ostracodtoxkit®. Proposed methodology allows the identification of contamination sources and non contaminated areas, corresponding to decreasing toxicity values.

Occurrence and In Vitro Bioactivity of Estrogen, Androgen, and Glucocorticoid Compounds in a Nationwide Screen of United States Stream Waters.

PubMed

Conley, Justin M; Evans, Nicola; Cardon, Mary C; Rosenblum, Laura; Iwanowicz, Luke R; Hartig, Phillip C; Schenck, Kathleen M; Bradley, Paul M; Wilson, Vickie S

2017-05-02

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states and Puerto Rico. ER agonism was the most frequently detected with nearly all sites (34/35) displaying activity (range, 0.054-116 ng E2Eq L -1 ). There was a strong linear relationship (r 2 = 0.917) between in vitro ER activity and concentrations of steroidal estrogens after correcting for the in vitro potency of each compound. AR agonism was detected in 5/35 samples (range, 1.6-4.8 ng DHTEq L -1 ) but concentrations of androgenic compounds were largely unable to account for the in vitro activity. Similarly, GR agonism was detected in 9/35 samples (range, 6.0-43 ng DexEq L -1 ); however, none of the recognized GR-active compounds on the target-chemical analyte list were detected. The utility of in vitro assays in water quality monitoring was evident from both the quantitative agreement between ER activity and estrogen concentrations, as well as the detection of AR and GR activity for which there were limited or no corresponding target-chemical detections to explain the bioactivity. Incorporation of in vitro bioassays as complements to chemical analyses in standard water quality monitoring efforts would allow for more complete assessment of the chemical mixtures present in many surface waters.

Occurrence and in vitro bioactivity of estrogen, androgen, and glucocorticoid compounds in a nationwide screen of United States stream waters

USGS Publications Warehouse

Conley, Justin M.; Evans, Nicola; Cardon, Mary C.; Rosenblum, Laura; Iwanowicz, Luke R.; Hartig, Phillip C.; Schenck, Kathleen M.; Bradley, Paul M.; Wilson, Vickie S.

2017-01-01

In vitro bioassays are sensitive, effect-based tools used to quantitatively screen for chemicals with nuclear receptor activity in environmental samples. We measured in vitro estrogen (ER), androgen (AR), and glucocorticoid receptor (GR) activity, along with a broad suite of chemical analytes, in streamwater from 35 well-characterized sites (3 reference and 32 impacted) across 24 states and Puerto Rico. ER agonism was the most frequently detected with nearly all sites (34/35) displaying activity (range, 0.054–116 ng E2Eq L–1). There was a strong linear relationship (r2 = 0.917) between in vitro ER activity and concentrations of steroidal estrogens after correcting for the in vitro potency of each compound. AR agonism was detected in 5/35 samples (range, 1.6–4.8 ng DHTEq L–1) but concentrations of androgenic compounds were largely unable to account for the in vitro activity. Similarly, GR agonism was detected in 9/35 samples (range, 6.0–43 ng DexEq L–1); however, none of the recognized GR-active compounds on the target-chemical analyte list were detected. The utility of in vitro assays in water quality monitoring was evident from both the quantitative agreement between ER activity and estrogen concentrations, as well as the detection of AR and GR activity for which there were limited or no corresponding target-chemical detections to explain the bioactivity. Incorporation of in vitro bioassays as complements to chemical analyses in standard water quality monitoring efforts would allow for more complete assessment of the chemical mixtures present in many surface waters.

Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui

PubMed Central

Bishop, James M.

2016-01-01

Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N) parameters (δ15N, N %, and C:N) were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF); this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s) and relative N loading is proposed for Hawaiʻi. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands. PMID:27812171

Impact of Submarine Groundwater Discharge on Marine Water Quality and Reef Biota of Maui.

PubMed

Amato, Daniel W; Bishop, James M; Glenn, Craig R; Dulai, Henrietta; Smith, Celia M

2016-01-01

Generally unseen and infrequently measured, submarine groundwater discharge (SGD) can transport potentially large loads of nutrients and other land-based contaminants to coastal ecosystems. To examine this linkage we employed algal bioassays, benthic community analysis, and geochemical methods to examine water quality and community parameters of nearshore reefs adjacent to a variety of potential, land-based nutrient sources on Maui. Three common reef algae, Acanthophora spicifera, Hypnea musciformis, and Ulva spp. were collected and/or deployed at six locations with SGD. Algal tissue nitrogen (N) parameters (δ15N, N %, and C:N) were compared with nutrient and δ15N-nitrate values of coastal groundwater and nearshore surface water at all locations. Benthic community composition was estimated for ten 10-m transects per location. Reefs adjacent to sugarcane farms had the greatest abundance of macroalgae, low species diversity, and the highest concentrations of N in algal tissues, coastal groundwater, and marine surface waters compared to locations with low anthropogenic impact. Based on δ15N values of algal tissues, we estimate ca. 0.31 km2 of Kahului Bay is impacted by effluent injected underground at the Kahului Wastewater Reclamation Facility (WRF); this region is barren of corals and almost entirely dominated by colonial zoanthids. Significant correlations among parameters of algal tissue N with adjacent surface and coastal groundwater N indicate that these bioassays provided a useful measure of nutrient source and loading. A conceptual model that uses Ulva spp. tissue δ15N and N % to identify potential N source(s) and relative N loading is proposed for Hawai'i. These results indicate that SGD can be a significant transport pathway for land-based nutrients with important biogeochemical and ecological implications in tropical, oceanic islands.

Advances in Toxico-Cheminformatics: Supporting a New ...

EPA Pesticide Factsheets

EPA’s National Center for Computational Toxicology is building capabilities to support a new paradigm for toxicity screening and prediction through the harnessing of legacy toxicity data, creation of data linkages, and generation of new high-throughput screening (HTS) data. The DSSTox project is working to improve public access to quality structure-annotated chemical toxicity information in less summarized forms than traditionally employed in SAR modeling, and in ways that facilitate both data-mining and read-across. Both DSSTox Structure-Files and the dedicated on-line DSSTox Structure-Browser are enabling seamless structure-based searching and linkages to and from previously isolated, chemically indexed public toxicity data resources (e.g., NTP, EPA IRIS, CPDB). Most recently, structure-enabled search capabilities have been extended to chemical exposure-related microarray experiments in the public EBI Array Express database, additionally linking this resource to the NIEHS CEBS toxicogenomics database. The public DSSTox chemical and bioassay inventory has been recently integrated into PubChem, allowing a user to take full advantage of PubChem structure-activity and bioassay clustering features. The DSSTox project is providing cheminformatics support for EPA’s ToxCastTM project, as well as supporting collaborations with the National Toxicology Program (NTP) HTS and the NIH Chemical Genomics Center (NCGC). Phase I of the ToxCastTM project is generating HT

High-throughput screening and mechanism-based evaluation of estrogenic botanical extracts

PubMed Central

Overk, Cassia R.; Yao, Ping; Chen, Shaonong; Deng, Shixing; Imai, Ayano; Main, Matthew; Schinkovitz, Andreas; Farnsworth, Norman R.; Pauli, Guido F.; Bolton, Judy L.

2009-01-01

Symptoms associated with menopause can greatly affect the quality of life for women. Botanical dietary supplements have been viewed by the public as safe and effective despite a lack of evidence indicating a urgent necessity to standardize these supplements chemically and biologically. Seventeen plants were evaluated for estrogenic biological activity using standard assays: competitive estrogen receptor (ER) binding assay for both alpha and beta subtypes, transient transfection of the estrogen response element luciferase plasmid into MCF-7 cells expressing either ER alpha or ER beta, and the Ishikawa alkaline phosphatase induction assay for both estrogenic and antiestrogenic activities. Based on the combination of data pooled from these assays, the following was determined: a) a high rate of false positive activity for the competitive binding assays, b) some extracts had estrogenic activity despite a lack of ability to bind the ER, c) one extract exhibited selective estrogen receptor modulator (SERM) activity, and d) several extracts show additive/synergistic activity. Taken together, these data indicate a need to reprioritize the order in which the bioassays are performed for maximal efficiency of programs involving bioassay-guided fractionation. In addition, possible explanations for the conflicts in the literature over the estrogenicity of Cimicifuga racemosa (black cohosh) are suggested. PMID:18473738

Chlorine toxicity to early life stages of freshwater mussels (Bivalvia: Unionidae)

USGS Publications Warehouse

Valenti, T.W.; Cherry, D.S.; Currie, R.J.; Neves, R.J.; Jones, J.W.; Mair, R.; Kane, C.M.

2006-01-01

Chlorine (Cl) is a highly toxic, widely used halogen disinfectant that is present in point-source pollution discharges from wastewater treatment plants and industrial facilities. The U.S. Environmental Protection Agency freshwater criteria for Cl are 19 ??g total residual Cl (TRC)/L as a maximum 1-h average concentration and 11 ??g TRC/L as a maximum 4-d average; however, toxicological data for unionids were not used in these calculations. To address this void in the data, we conducted acute tests with glochidia from several species and 21-d bioassays with three-month-old Epioblasma capsaeformis and three-, six-, and 12-month-old Villosa iris juveniles. The 24-h lethal concentration 50 values for glochidia were between 70 and 220 ??g TRC/L, which are 2.5 to 37 times higher than those reported in other studies for cladocerans. Significant declines in growth and survivorship were observed in the 21-d test with E. capsaeformis at 20 ??g TRC/L. Lowest-observed-adverse- effects concentrations in bioassays with juvenile V. iris were higher (30-60 ??g TRC/L) but showed a significant trend of declining toxicity with increased age. Although endpoints were above water quality criteria, the long life spans of unionids and potential implications of chronic exposure to endangered juvenile mussels still warrant concern. ?? 2006 SETAC.