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Sample records for chip-scale bioassays based

  1. Chip-Scale Bioassays Based on Surface-Enhanced Raman Scattering: Fundamentals and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Hye-Young Park

    2005-12-17

    This work explores the development and application of chip-scale bioassays based on surface-enhanced Raman scattering (SERS) for high throughput and high sensitivity analysis of biomolecules. The size effect of gold nanoparticles on the intensity of SERS is first presented. A sandwich immunoassay was performed using Raman-labeled immunogold nanoparticles with various sizes. The SERS responses were correlated to particle densities, which were obtained by atomic force microscopy (AFM). The response of individual particles was also investigated using Raman-microscope and an array of gold islands on a silicon substrate. The location and the size of individual particles were mapped using AFM. The next study describes a low-level detection of Escherichia coli 0157:H7 and simulants of biological warfare agents in a sandwich immunoassay format using SERS labels, which have been termed Extrinsic Raman labels (ERLs). A new ERL scheme based on a mixed monolayer is also introduced. The mixed monolayer ERLs were created by covering the gold nanoparticles with a mixture of two thiolates, one thiolate for covalently binding antibody to the particle and the other thiolate for producing a strong Raman signal. An assay platform based on mixed self-assembled monolayers (SAMs) on gold is then presented. The mixed SAMs were prepared from dithiobis(succinimidyl undecanoate) (DSU) to covalently bind antibodies on gold substrate and oligo(ethylene glycol)-terminated thiol to prevent nonspecific adsorption of antibodies. After the mixed SAMs surfaces, formed from various mole fraction of DSU were incubated with antibodies, AFM was used to image individual antibodies on the surface. The final study presents a collaborative work on the single molecule adsorption of YOYO-I labeled {lambda}-DNA at compositionally patterned SAMs using total internal reflection fluorescence microscopy. The role of solution pH, {lambda}-DNA concentration, and domain size was investigated. This work also revealed

  2. Chip-Scale Bioassays Based on Surface-Enhanced Raman Scattering: Fundamentals and Applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye-Young [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    This work explores the development and application of chip-scale bioassays based on surface-enhanced Raman scattering (SERS) for high throughput and high sensitivity analysis of biomolecules. The size effect of gold nanoparticles on the intensity of SERS is first presented. A sandwich immunoassay was performed using Raman-labeled immunogold nanoparticles with various sizes. The SERS responses were correlated to particle densities, which were obtained by atomic force microscopy (AFM). The response of individual particles was also investigated using Raman-microscope and an array of gold islands on a silicon substrate. The location and the size of individual particles were mapped using AFM. The next study describes a low-level detection of Escherichia coli 0157:H7 and simulants of biological warfare agents in a sandwich immunoassay format using SERS labels, which have been termed Extrinsic Raman labels (ERLs). A new ERL scheme based on a mixed monolayer is also introduced. The mixed monolayer ERLs were created by covering the gold nanoparticles with a mixture of two thiolates, one thiolate for covalently binding antibody to the particle and the other thiolate for producing a strong Raman signal. An assay platform based on mixed self-assembled monolayers (SAMs) on gold is then presented. The mixed SAMs were prepared from dithiobis(succinimidyl undecanoate) (DSU) to covalently bind antibodies on gold substrate and oligo(ethylene glycol)-terminated thiol to prevent nonspecific adsorption of antibodies. After the mixed SAMs surfaces, formed from various mole fraction of DSU were incubated with antibodies, AFM was used to image individual antibodies on the surface. The final study presents a collaborative work on the single molecule adsorption of YOYO-I labeled {lambda}-DNA at compositionally patterned SAMs using total internal reflection fluorescence microscopy. The role of solution pH, {lambda}-DNA concentration, and domain size was investigated. This work also revealed

  3. Bioassays Based on Molecular Nanomechanics

    Directory of Open Access Journals (Sweden)

    Arun Majumdar

    2002-01-01

    Full Text Available Recent experiments have shown that when specific biomolecular interactions are confined to one surface of a microcantilever beam, changes in intermolecular nanomechanical forces provide sufficient differential torque to bend the cantilever beam. This has been used to detect single base pair mismatches during DNA hybridization, as well as prostate specific antigen (PSA at concentrations and conditions that are clinically relevant for prostate cancer diagnosis. Since cantilever motion originates from free energy change induced by specific biomolecular binding, this technique is now offering a common platform for label-free quantitative analysis of protein-protein binding, DNA hybridization DNA-protein interactions, and in general receptor-ligand interactions. Current work is focused on developing “universal microarrays” of microcantilever beams for high-throughput multiplexed bioassays.

  4. Large-field-of-view Chip-scale Talbot-grid-based Fluorescence Microscopy

    CERN Document Server

    Pang, Shuo; Kato, Mihoko; Sternberg, Paul W; Yang, Changhuei

    2012-01-01

    The fluorescence microscope is one of the most important tools in modern clinical diagnosis and biological science. However, its expense, size and limited field-of-view (FOV) are becoming bottlenecks in key applications such as large-scale phenotyping and low-resource-setting diagnostics. Here we report a low-cost, compact chip-scale fluorescence-imaging platform, termed the Fluorescence Talbot Microscopy (FTM), which utilizes the Talbot self-imaging effect to enable efficient fluorescence imaging over a large and directly-scalable FOV. The FTM prototype has a resolution of 1.2 microns and an FOV of 3.9 mm x 3.5 mm. We demonstrate the imaging capability of FTM on fluorescently labeled breast cancer cells (SK-BR-3) and HEK cells expressing green fluorescent protein.

  5. A Nisin Bioassay Based on Bioluminescence

    OpenAIRE

    Wahlström, G.; Saris, P. E. J.

    1999-01-01

    A Lactococcus lactis subsp. lactis strain that can sense the bacteriocin nisin and transduce the signal into bioluminescence was constructed. By using this strain, a bioassay based on bioluminescence was developed for quantification of nisin, for detection of nisin in milk, and for identification of nisin-producing strains. As little as 0.0125 ng of nisin per ml was detected within 3 h by this bioluminescence assay. This detection limit was lower than in previously described methods.

  6. Microfabricated cells for chip-scale atomic clock based on coherent population trapping: Fabrication and investigation

    Directory of Open Access Journals (Sweden)

    S.V. Ermak

    2015-03-01

    Full Text Available A universal method for fabrication of miniature cells for frequency standards and quantum magnetometers containing 87Rb atoms in the atmosphere of inert gas neon based on integrated technologies is considered. The results of experimental studies of coherent population trapping signals observed for a series of cells which provided recovery of vapors of an alkali metal from the rubidium dichromate salt with the help of laser radiation are presented. The coherent population trapping signals with a typical linewidth of 2–3 kHz and a signal-to-noise ratio of 1500 in the 1-Hz bandwidth were observed, which allows one to provide a relative frequency stability of atomic clock of 10−11 at 100 s.

  7. Cell-based bioassays in microfluidic systems

    Science.gov (United States)

    Itle, Laura J.; Zguris, Jeanna C.; Pishko, Michael V.

    2004-12-01

    The development of cell-based bioassays for high throughput drug screening or the sensing of biotoxins is contingent on the development of whole cell sensors for specific changes in intracellular conditions and the integration of those systems into sample delivery devices. Here we show the feasibility of using a 5-(and-6)-carboxy SNARF-1, acetoxymethyl ester, acetate, a fluorescent dye capable of responding to changes in intracellular pH, as a detection method for the bacterial endotoxin, lipopolysaccharide. We used photolithography to entrap cells with this dye within poly(ethylene) glyocol diacrylate hydrogels in microfluidic channels. After 18 hours of exposure to lipopolysaccharide, we were able to see visible changes in the fluorescent pattern. This work shows the feasibility of using whole cell based biosensors within microfluidic networks to detect cellular changes in response to exogenous agents.

  8. A chip scale optical Tx/Rx based on silicon photonics from views of multi-mode transmission

    Science.gov (United States)

    Ogura, Ichiro; Yashiki, Kenichiro; Suzuki, Yasuyuki; Hagihara, Yasuhiko; Nakamura, Takahiro; Kurata, Kazuhiko

    2016-03-01

    This paper focuses on latest progress in experimental and theoretical studies on silicon-based carrier-depletion PN-junction phase shifters in terms of high modulation efficiency for energy-efficient photonic networks of high transmission capacity. Modulation efficiency of rib-waveguide phase shifters having various PN-junction configuration are characterized with respect to DC figure of merit defined for phase shifters using carrier-plasma dispersion as the physical principle of refractive-index modulation. In addition, RF drive voltage required for 10-Gb/s on-off keying is characterized for rib-waveguide phase shifters including lateral and vertical PN-junction configurations.

  9. Microfluidic System for Solution Array Based Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Dougherty, G M; Tok, J B; Pannu, S S; Rose, K A

    2006-02-10

    The objective of this project is to demonstrate new enabling technology for multiplex biodetection systems that are flexible, miniaturizable, highly automated, low cost, and high performance. It builds on prior successes at LLNL with particle-based solution arrays, such as those used in the Autonomous Pathogen Detection System (APDS) successfully field deployed to multiple locations nationwide. We report the development of a multiplex solution array immunoassay based upon engineered metallic nanorod particles. Nanobarcodes{reg_sign} particles are fabricated by sequential electrodeposition of dissimilar metals within porous alumina templates, yielding optically encoded striping patterns that can be read using standard laboratory microscope optics and PC-based image processing software. The addition of self-assembled monolayer (SAM) coatings and target-specific antibodies allows each encoded class of nanorod particles to be directed against a different antigen target. A prototype assay panel directed against bacterial, viral, and soluble protein targets demonstrates simultaneous detection at sensitivities comparable to state of the art immunoassays, with minimal cross-reactivity. Studies have been performed to characterize the colloidal properties (zeta potential) of the suspended nanorod particles as a function of pH, the ionic strength of the suspending solution, and surface functionalization state. Additional studies have produced means for the non-contact manipulation of the particles, including the insertion of magnetic nickel stripes within the encoding pattern, and control via externally applied electromagnetic fields. Using the results of these studies, the novel Nanobarcodes{reg_sign} based assay was implemented in a prototype automated system with the sample processing functions and optical readout performed on a microfluidic card. The unique physical properties of the nanorod particles enable the development of integrated microfluidic systems for

  10. Chip-scale parametric amplifier with 11 dB gain at 1550 nm based on a slow-light GaInP photonic crystal waveguide.

    Science.gov (United States)

    Cestier, Isabelle; Combrié, Sylvain; Xavier, Stéphane; Lehoucq, Gaëlle; De Rossi, Alfredo; Eisenstein, Gadi

    2012-10-01

    We report on a chip scale parametric amplifier based on a GaInP photonic crystal waveguide. The amplifier operates with both pump and signal in the 1550 nm wavelength range and offers an on-chip gain of 11 dB (5 dB including the 6 dB coupling losses) when pumped at only 800 mW. It enables us, therefore, to incorporate the many advantages of parametric amplification within photonic chips for optical communication applications.

  11. [Investigation on pattern and methods of quality control for Chinese materia medica based on dao-di herbs and bioassay - bioassay for Coptis chinensis].

    Science.gov (United States)

    Yan, Dan; Xiao, Xiao-he

    2011-05-01

    Establishment of bioassay methods is the technical issues to be faced with in the bioassay of Chinese materia medica. Taking the bioassay of Coptis chinensis Franch. as an example, the establishment process and application of the bioassay methods (including bio-potency and bio-activity fingerprint) were explained from the aspects of methodology, principle of selection, experimental design, method confirmation and data analysis. The common technologies were extracted and formed with the above aspects, so as to provide technical support for constructing pattern and method of the quality control for Chinese materia medica based on the dao-di herbs and bioassay. PMID:21800546

  12. The Text-mining based PubChem Bioassay neighboring analysis

    Directory of Open Access Journals (Sweden)

    Wang Yanli

    2010-11-01

    Full Text Available Abstract Background In recent years, the number of High Throughput Screening (HTS assays deposited in PubChem has grown quickly. As a result, the volume of both the structured information (i.e. molecular structure, bioactivities and the unstructured information (such as descriptions of bioassay experiments, has been increasing exponentially. As a result, it has become even more demanding and challenging to efficiently assemble the bioactivity data by mining the huge amount of information to identify and interpret the relationships among the diversified bioassay experiments. In this work, we propose a text-mining based approach for bioassay neighboring analysis from the unstructured text descriptions contained in the PubChem BioAssay database. Results The neighboring analysis is achieved by evaluating the cosine scores of each bioassay pair and fraction of overlaps among the human-curated neighbors. Our results from the cosine score distribution analysis and assay neighbor clustering analysis on all PubChem bioassays suggest that strong correlations among the bioassays can be identified from their conceptual relevance. A comparison with other existing assay neighboring methods suggests that the text-mining based bioassay neighboring approach provides meaningful linkages among the PubChem bioassays, and complements the existing methods by identifying additional relationships among the bioassay entries. Conclusions The text-mining based bioassay neighboring analysis is efficient for correlating bioassays and studying different aspects of a biological process, which are otherwise difficult to achieve by existing neighboring procedures due to the lack of specific annotations and structured information. It is suggested that the text-mining based bioassay neighboring analysis can be used as a standalone or as a complementary tool for the PubChem bioassay neighboring process to enable efficient integration of assay results and generate hypotheses for

  13. Efficient algal bioassay based on short-term photosynthetic response

    International Nuclear Information System (INIS)

    A procedure is described for measuring the effects of toxicants on algal photosynthesis (carbon-14 bicarbonate (H14CO3)uptake) in 4-h experiments. The results for individual aromatic compounds and the water-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and the responses of some species were pH-dependent. With Selenastrum capricornutum as the test organism, the bioassay results were unaffected by variations in pH from 7.0 to 9.0, light intensity from 40 to 200 μeinsteins m-2 s-1, culture density up to 0.5 mg chlorophyll a per litre, and agitation up to 100 rpm. The photosynthesis bioassay is simpler and faster (4 h versus 4 to 14 days), uses smaller culture volumes, and requires less space than static culture-growth tests. One person can conveniently test four materials per day, and the entire procedure, including preparation, exposure, and analysis, takes less than two days. The short incubation time reduces bottle effects such as pH changes, accumulation of metabolic products, nutrient depletion, and bacterial growth. Processes that remove or alter the test materials are also minimized. The data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (seven-day) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects. 25 references, 6 figures, 1 table

  14. A fluorescence-based bioassay for antibacterials and its application in screening natural product extracts

    NARCIS (Netherlands)

    Michels, Katharina; Heinke, Ramona; Schöne, Pia; Kuipers, Oscar P; Arnold, Norbert; Wessjohann, Ludger A

    2015-01-01

    The reliable assessment of the biological activity of a minor component embedded in a complex matrix of several hundred compounds is a difficult but common task in the search for natural product-based antibiotics, for example, by bioassay-guided fractionation. To quantify the antibiotic properties,

  15. In Vitro Biologic Activities of the Antimicrobials Triclocarban, Its Analogs, and Triclosan in Bioassay Screens: Receptor-Based Bioassay Screens

    OpenAIRE

    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 ac...

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

    Science.gov (United States)

    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

    2016-03-01

    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

  17. Fluorescence-Based Bioassays for the Detection and Evaluation of Food Materials

    Directory of Open Access Journals (Sweden)

    Kentaro Nishi

    2015-10-01

    Full Text Available We summarize here the recent progress in fluorescence-based bioassays for the detection and evaluation of food materials by focusing on fluorescent dyes used in bioassays and applications of these assays for food safety, quality and efficacy. Fluorescent dyes have been used in various bioassays, such as biosensing, cell assay, energy transfer-based assay, probing, protein/immunological assay and microarray/biochip assay. Among the arrays used in microarray/biochip assay, fluorescence-based microarrays/biochips, such as antibody/protein microarrays, bead/suspension arrays, capillary/sensor arrays, DNA microarrays/polymerase chain reaction (PCR-based arrays, glycan/lectin arrays, immunoassay/enzyme-linked immunosorbent assay (ELISA-based arrays, microfluidic chips and tissue arrays, have been developed and used for the assessment of allergy/poisoning/toxicity, contamination and efficacy/mechanism, and quality control/safety. DNA microarray assays have been used widely for food safety and quality as well as searches for active components. DNA microarray-based gene expression profiling may be useful for such purposes due to its advantages in the evaluation of pathway-based intracellular signaling in response to food materials.

  18. Use of viral promoters in mammalian cell-based bioassays: How reliable?

    OpenAIRE

    Gill-Sharma Manjit; Choudhuri Jyoti; Betrabet Shrikant S

    2004-01-01

    Abstract Cell-based bioassays have been suggested for screening of hormones and drug bioactivities. They are a plausible alternative to animal based methods. The technique used is called receptor/reporter system. Receptor/reporter system was initially developed as a research technique to understand gene function. Often reporter constructs containing viral promoters were used because they could be expressed with very 'high' magnitude in a variety of cell types in the laboratory. On the other h...

  19. Development of bacteria-based bioassays for arsenic detection in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Diesel, Elizabeth; Schreiber, Madeline [Virginia Tech, Department of Geosciences, Blacksburg, VA (United States); Meer, Jan Roelof van der [University of Lausanne, Department of Fundamental Microbiology, Lausanne (Switzerland)

    2009-06-15

    Arsenic contamination of natural waters is a worldwide concern, as the drinking water supplies for large populations can have high concentrations of arsenic. Traditional techniques to detect arsenic in natural water samples can be costly and time-consuming; therefore, robust and inexpensive methods to detect arsenic in water are highly desirable. Additionally, methods for detecting arsenic in the field have been greatly sought after. This article focuses on the use of bacteria-based assays as an emerging method that is both robust and inexpensive for the detection of arsenic in groundwater both in the field and in the laboratory. The arsenic detection elements in bacteria-based bioassays are biosensor-reporter strains; genetically modified strains of, e.g., Escherichia coli, Bacillus subtilis, Staphylococcus aureus, and Rhodopseudomonas palustris. In response to the presence of arsenic, such bacteria produce a reporter protein, the amount or activity of which is measured in the bioassay. Some of these bacterial biosensor-reporters have been successfully utilized for comparative in-field analyses through the use of simple solution-based assays, but future methods may concentrate on miniaturization using fiberoptics or microfluidics platforms. Additionally, there are other potential emerging bioassays for the detection of arsenic in natural waters including nematodes and clams. (orig.)

  20. Terabit/s communications using chip-scale frequency comb sources

    Science.gov (United States)

    Koos, Christian; Kippenberg, Tobias J.; Barry, Liam P.; Dalton, Larry; Freude, Wolfgang; Leuthold, Juerg; Pfeifle, Joerg; Weimann, Claudius; Lauermann, Matthias; Kemal, Juned N.; Palmer, Robert; Koeber, Sebastian; Schindler, Philipp C.; Herr, Tobias; Brasch, Victor; Watts, Regan T.; Elder, Delwin

    2015-03-01

    High-speed optical interconnects rely on advanced wavelength-division multiplexing (WDM) schemes. However, while photonic-electronic interfaces can be efficiently realized on silicon-on-insulator chips, dense integration of the necessary light sources still represents a major challenge. Chip-scale frequency comb sources present an attractive alternative for providing a multitude of optical carriers for WDM transmission. In this paper, we give an overview of our recent progress towards terabit communications with chip-scale frequency comb sources. In a first set of experiments, we demonstrate frequency comb generation based on silicon-organic hybrid (SOH) electro-optic modulators, enabling line rates up to 1.152 Tbit/s. In a second set of experiments, we use injection locking of a gain-switched laser diode to enerate frequency combs. This approach leads to line rates of more than 2 Tbit/s. A third set of experiments is finally dedicated to using Kerr nonlinearities in integrated nonlinear microcavities for frequency comb generation. We demonstrate coherent communication using Kerr frequency comb sources, thereby achieving line rates up to 1.44 Tbit/s. Our experiments show that frequency comb generation in chip-scale devices represents a viable approach to terabit communications.

  1. [Investigation on pattern of quality control for Chinese materia medica based on famous-region drug and bioassay--the work reference].

    Science.gov (United States)

    Yan, Dan; Xiao, Xiaohe

    2011-05-01

    Selection and standardization of the work reference are the technical issues to be faced with in the bioassay of Chinese materia medica. Taking the bioassay of Coptis chinensis. as an example, the manufacture process of the famous-region drugs extraction was explained from the aspects of original identification, routine examination, component analysis and bioassay. The common technologies were extracted, and the selection and standardization procedures of the work reference for the bioassay of Chinese materia medica were drawn up, so as to provide technical support for constructing a new mode and method of the quality control of Chinese materia medica based on the famous-region drugs and bioassay. PMID:21842660

  2. Development of a cell-based bioassay for phospholipase A2-triggered liposomal drug release.

    Directory of Open Access Journals (Sweden)

    Ahmad Arouri

    Full Text Available The feasibility of exploiting secretory phospholipase A2 (sPLA2 enzymes, which are overexpressed in tumors, to activate drug release from liposomes precisely at the tumor site has been demonstrated before. Although the efficacy of the developed formulations was evaluated using in vitro and in vivo models, the pattern of sPLA2-assisted drug release is unknown due to the lack of a suitable bio-relevant model. We report here on the development of a novel bioluminescence living-cell-based luciferase assay for the monitoring of sPLA2-triggered release of luciferin from liposomes. To this end, we engineered breast cancer cells to produce both luciferase and sPLA2 enzymes, where the latter is secreted to the extracellular medium. We report on setting up a robust and reproducible bioassay for testing sPLA2-sensitive, luciferin remote-loaded liposomal formulations, using 1,2-distearoyl-sn-glycero-3-phosphatidylcholine/1,2-distearoyl-sn-glycero-3-phosphatidylglycerol (DSPC/DSPG 7:3 and DSPC/DSPG/cholesterol 4:3:3 as initial test systems. Upon their addition to the cells, the liposomes were degraded almost instantaneously by sPLA2 releasing the encapsulated luciferin, which provided readout from the luciferase-expressing cells. Cholesterol enhanced the integrity of the formulation without affecting its susceptibility to sPLA2. PEGylation of the liposomes only moderately broadened the release profile of luciferin. The provided bioassay represents a useful tool for monitoring active drug release in situ in real time as well as for testing and optimizing of sPLA2-sensitive lipid formulations. In addition, the bioassay will pave the way for future in-depth in vitro and in vivo studies.

  3. Use of viral promoters in mammalian cell-based bioassays: How reliable?

    Directory of Open Access Journals (Sweden)

    Gill-Sharma Manjit

    2004-01-01

    Full Text Available Abstract Cell-based bioassays have been suggested for screening of hormones and drug bioactivities. They are a plausible alternative to animal based methods. The technique used is called receptor/reporter system. Receptor/reporter system was initially developed as a research technique to understand gene function. Often reporter constructs containing viral promoters were used because they could be expressed with very 'high' magnitude in a variety of cell types in the laboratory. On the other hand mammalian genes are expressed in a cell/tissue specific manner, which makes them (i.e. cells/tissues specialized for specific function in vivo. Therefore, if the receptor/reporter system is to be used as a cell-based screen for testing of hormones and drugs for human therapy then the choice of cell line as well as the promoter in the reporter module is of prime importance so as to get a realistic measure of the bioactivities of 'test' compounds. We evaluated two conventionally used viral promoters and a natural mammalian promoter, regulated by steroid hormone progesterone, in a cell-based receptor/reporter system. The promoters were spliced into vectors expressing enzyme CAT (chloramphenicol acetyl transferase, which served as a reporter of their magnitudes and consistencies in controlling gene expressions. They were introduced into breast cell lines T47D and MCF-7, which served as a cell-based source of progesterone receptors. The yardstick of their reliability was highest magnitude as well as consistency in CAT expression on induction by sequential doses of progesterone. All the promoters responded to induction by progesterone doses ranging from 10-12 to 10-6 molar by expressing CAT enzyme, albeit with varying magnitudes and consistencies. The natural mammalian promoter showed the most coherence in magnitude as well as dose dependent expression profile in both the cell lines. Our study casts doubts on use of viral promoters in a cell-based bioassay for

  4. Single-core magnetic markers in rotating magnetic field based homogeneous bioassays and the law of mass action

    Energy Technology Data Exchange (ETDEWEB)

    Dieckhoff, Jan, E-mail: j.dieckhoff@tu-bs.de [Institut fuer Elektrische Messtechnik und Grundlagen der Elektrotechnik, TU Braunschweig, Braunschweig (Germany); Schrittwieser, Stefan; Schotter, Joerg [Molecular Diagnostics, AIT Austrian Institute of Technology, Vienna (Austria); Remmer, Hilke; Schilling, Meinhard; Ludwig, Frank [Institut fuer Elektrische Messtechnik und Grundlagen der Elektrotechnik, TU Braunschweig, Braunschweig (Germany)

    2015-04-15

    In this work, we report on the effect of the magnetic nanoparticle (MNP) concentration on the quantitative detection of proteins in solution with a rotating magnetic field (RMF) based homogeneous bioassay. Here, the phase lag between 30 nm iron oxide single-core particles and the RMF is analyzed with a fluxgate-based measurement system. As a test analyte anti-human IgG is applied which binds to the protein G functionalized MNP shell and causes a change of the phase lag. The measured phase lag changes for a fixed MNP and a varying analyte concentration are modeled with logistic functions. A change of the MNP concentration results in a nonlinear shift of the logistic function with the analyte concentration. This effect results from the law of mass action. Furthermore, the bioassay results are used to determine the association constant of the binding reaction. - Highlights: • A rotating magnetic field based homogeneous bioassay concept was presented. • Here, single-core iron oxide nanoparticles are applied as markers. • The impact of the particle concentration on the bioassay results is investigated. • The relation between particle concentration and bioassay sensitivity is nonlinear. • This finding can be reasonably explained by the law of mass action.

  5. Active Solar Sail Designs for Chip-Scale Spacecraft

    OpenAIRE

    Weis, Lorraine; Peck, Mason

    2014-01-01

    Centimeter-scale spacecraft, known as ”Chipsats,” have very high surface-area-to-mass ratios, which accentuates solar radiation pressure (SRP) effects. In contrast to traditional. large solar sails, chip-scale solar sails have the potential to be highly agile in terms of attitude because of their structural rigidity and low moments of inertia. This ability to easily reorient a solar sail greatly expands the orbits that a solar-sail spacecraft can achieve. Solar sail actuation through electroc...

  6. Chip-scale cavity optomechanics in lithium niobate

    OpenAIRE

    Jiang, Wei C.; LIN, QIANG

    2016-01-01

    We develop a chip-scale cavity optomechanical system in single-crystal lithium niobate that exhibits high optical quality factors and a large frequency-quality product as high as $3.6\\times 10^{12}$ Hz at room temperature and atmosphere. The excellent optical and mechanical properties together with the strong optomechanical coupling allow us to efficiently excite the coherent regenerative optomechanical oscillation operating at 375.8 MHz with a threshold power of 174 ${\\rm \\mu W}$ in the air....

  7. Chip-scale cavity optomechanics in lithium niobate

    CERN Document Server

    Jiang, Wei C

    2016-01-01

    We develop a chip-scale cavity optomechanical system in single-crystal lithium niobate that exhibits high optical quality factors and a large frequency-quality product as high as $3.6\\times 10^{12}$ Hz at room temperature and atmosphere. The excellent optical and mechanical properties together with the strong optomechanical coupling allow us to efficiently excite the coherent regenerative optomechanical oscillation operating at 375.8 MHz with a threshold power of 174 ${\\rm \\mu W}$ in the air. The demonstrated lithium niobate optomechanical device enables great potential for achieving electro-optic-mechanical hybrid systems for broad applications in sensing, metrology, and quantum physics.

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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

  11. Bioassay based screening of steroid derivatives in animal feed and supplements

    NARCIS (Netherlands)

    Rijk, J.C.W.; Ashwin, H.M.; Kuijk, van S.J.A.; Groot, M.J.; Heskamp, H.H.; Bovee, T.F.H.; Nielen, M.W.F.

    2011-01-01

    Receptor binding transcription activation bioassays are valuable tools for the screening of steroid hormones in animal feed and supplements. However, steroid derivatives often lack affinity for their cognate receptor and do not show any direct hormonal activity by themselves. These compounds are thu

  12. Detection of marine microalgal biotoxins using bioassays based on functional expression of tunicate xenobiotic receptors in yeast.

    Science.gov (United States)

    Richter, Ingrid; Fidler, Andrew E

    2015-03-01

    Marine microalgae can produce biotoxins that cause widespread poisoning in marine ecosystems and may also affect human health. While established microalgal biotoxins are detectable using chemical methods, a need remains for robust, inexpensive bioassays. Ligand-binding domains (LBDs) from a tunicate nuclear receptor, VDR/PXRα, which is orthologous to both the vertebrate pregnane X receptor (PXR) and the vitamin D receptor (VDR), can be activated by microalgal biotoxins when expressed in mammalian cell lines. Building on this observation, we developed a generic recombinant yeast bioassay platform that expresses chimeric proteins containing tunicate VDR/PXRα LBDs which mediate ligand-dependent transcription of a reporter gene (lacZ) encoding an easily assayed enzyme (β-galactosidase). Recombinant yeast strains expressing VDR/PXRα LBDs from two tunicate species, Ciona intestinalis and Botryllus schlosseri, were exposed to both synthetic and natural toxins. Structurally simple synthetic chemicals (n-butyl-p-aminobenzoate, carbamazepine, p-aminobenzoic acid, and bisphenol-A) generated EC50 values in the μM range, while more structurally complex marine biotoxins (okadaic acid, pectenotoxin-11, and portimine) activated the assays in the nM range. Given the large number of tunicate species, we propose that tunicate VDR/PXR LBDs may be used as 'sensor elements' in similar yeast-based high-throughput bioassays for detection of established microalgal biotoxins and uncharacterised marine bioactive compounds.

  13. Detection of marine microalgal biotoxins using bioassays based on functional expression of tunicate xenobiotic receptors in yeast.

    Science.gov (United States)

    Richter, Ingrid; Fidler, Andrew E

    2015-03-01

    Marine microalgae can produce biotoxins that cause widespread poisoning in marine ecosystems and may also affect human health. While established microalgal biotoxins are detectable using chemical methods, a need remains for robust, inexpensive bioassays. Ligand-binding domains (LBDs) from a tunicate nuclear receptor, VDR/PXRα, which is orthologous to both the vertebrate pregnane X receptor (PXR) and the vitamin D receptor (VDR), can be activated by microalgal biotoxins when expressed in mammalian cell lines. Building on this observation, we developed a generic recombinant yeast bioassay platform that expresses chimeric proteins containing tunicate VDR/PXRα LBDs which mediate ligand-dependent transcription of a reporter gene (lacZ) encoding an easily assayed enzyme (β-galactosidase). Recombinant yeast strains expressing VDR/PXRα LBDs from two tunicate species, Ciona intestinalis and Botryllus schlosseri, were exposed to both synthetic and natural toxins. Structurally simple synthetic chemicals (n-butyl-p-aminobenzoate, carbamazepine, p-aminobenzoic acid, and bisphenol-A) generated EC50 values in the μM range, while more structurally complex marine biotoxins (okadaic acid, pectenotoxin-11, and portimine) activated the assays in the nM range. Given the large number of tunicate species, we propose that tunicate VDR/PXR LBDs may be used as 'sensor elements' in similar yeast-based high-throughput bioassays for detection of established microalgal biotoxins and uncharacterised marine bioactive compounds. PMID:25549942

  14. Chip-scale fully reconfigurable optical add/drop multiplexing subsystem in polymer microphotonic circuits

    Science.gov (United States)

    Izuhara, Tomoyuki; Fujita, Junichiro; Radojevic, Antonije; Gerhardt, Reinald; Eldada, Louay A.

    2004-10-01

    We report on a highly integrated photonic circuit using a polymer-based planar waveguide system. The properties of the materials used in this work such as ultra-low optical loss, widely tunable refractive index, and large thermo-optic coefficient, enable a multi-functional chip-scale microphotonic circuit. We discuss the application of this technology to the fabrication of a fully reconfigurable optical add/drop multiplexer. This subsystem includes channel switching, power monitoring, load balancing, and wavelength shuffling functionalities that are required for agile wavelength-division multiplexing optical networks. Optical properties of our material systems and performance characteristics of the implemented optical passive/active elements are presented, and the integration schemes of the devices to achieve a fully integrated reconfigurable optical add/drop multiplexer are discussed.

  15. Integrated chip-scale Si3N4 wavemeter with narrow free spectral range and high stability.

    Science.gov (United States)

    Xiang, Chao; Tran, Minh A; Komljenovic, Tin; Hulme, Jared; Davenport, Michael; Baney, Doug; Szafraniec, Bogdan; Bowers, John E

    2016-07-15

    We designed, fabricated, and characterized an integrated chip-scale wavemeter based on an unbalanced Mach-Zehnder interferometer with 300 MHz free spectral range. The wavemeter is realized in the Si3N4 platform, allowing for low loss with ∼62  cm of on-chip delay. We also integrated an optical hybrid to provide phase information. The main benefit of a fully integrated wavemeter, beside its small dimensions, is increased robustness to vibrations and temperature variations and much improved stability over fiber-based solutions. PMID:27420522

  16. Development and characterization of a green fluorescent protein-based rat cell bioassay system for detection of AH receptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Bin; Denison, M. [California Univ., Davis, CA (United States). Dept. of Environmental Toxicology

    2004-09-15

    Proper epidemiological, risk assessment and exposure analysis of TCDD and related HAHs requires accurate measurements of these chemicals both in the species of interest and in various exposure matrices (i.e. biological, environmental, food and feed). While high-resolution instrumental analysis techniques are established for these chemicals, these procedures are very costly, time-consuming and are impractical for large scale sampling studies. Accordingly, numerous bioanalytical methods have been developed for the detection of these chemicals in extracts from a variety of matrices, the majority of which take the advantage of the ability of these chemicals to activate one or more aspects of the AhR-dependent mechanism of action. One of the most sensitive bioassay systems developed to date is the so-called CALUX (Chemically Activated Luciferase Expression) assay, which is based on novel recombinant cell lines that contain a stably transfected dioxin (AhR)-responsive firefly luciferase gene. Treatment of these cells with TCDD and related HAHs and polycyclic aromatic hydrocarbons (PAHs), as well as other AhR ligands, results in induction of reporter gene expression in a time-, dose-, AhR-, and chemical-specific manner. The level of reporter gene expression correlates with the total concentration of the TCDD-like AhR inducers (agonists) present in the sample. Although the firefly luciferase reporter gene contributes to the high degree of sensitivity of the assay, it also has limitations with respect to our need for a rapid and inexpensive bioassay for high-throughput screening analysis. Accordingly, we previously developed a stably transfected murine cell line containing an AhRresponsive enhanced green fluorescent protein (EGFP) reporter gene. This cell line provided us with a high-throughput cell bioassay system for identification and characterization of AhR agonists and antagonists. Here we have extended these studies and describe the development, optimization, and

  17. Chlorine disinfection by-products in wastewater effluent: Bioassay-based assessment of toxicological impact.

    Science.gov (United States)

    Watson, K; Shaw, G; Leusch, F D L; Knight, N L

    2012-11-15

    The potential ecological impact of disinfection by-products (DBPs) present in chlorinated wastewater effluents is not well understood. In this study, the chlorinated effluent of traditional wastewater treatment plants (WWTPs) and advanced water reclamation plants (AWRPs) supplying highly-treated recycled water were analyzed for nitrosamines and trihalomethanes (THMs), and a battery of bioassays conducted to assess effluent toxicity. An increase in general toxicity from DBPs was revealed for all wastewaters studied using an in vitro bioluminescence assay. Examples of androgenic activity and estrogenic activity arising from DBPs at specific sampling sites were also observed. The in vivo model (Artemia franciscana) was generally not adversely affected by exposure to DBPs from any of the chlorinated wastewaters studied. The observed toxicity could not be related to the concentrations of THMs and nitrosamines present, indicating that DBPs not monitored in this study were responsible for this. This work highlights the complexity of DBPs mixtures formed in chlorinated wastewaters, illustrating that toxicity of wastewater DBPs cannot be predicted by chemical monitoring of THMs and nitrosamines. The results suggest bioassays may be particularly useful monitoring tools in assessing toxicity arising from DBPs of these complex waters. The research concludes that DBPs formed in the chlorinated wastewaters studied can be toxic and may have a deleterious impact on aquatic organisms that are exposed to them, and therefore, that chlorination or chlorination/dechlorination may not be adequate treatment strategies for the protection of receiving waters. Chlorinated wastewater toxicity (from DBPs) is not well-understood in the Australian context, and this study serves to advise regulators on this issue. PMID:22981491

  18. Thioglucose-stabilized gold nanoparticles as a novel platform for colorimetric bioassay based on nanoparticle aggregation.

    Science.gov (United States)

    Watanabe, Shigeru; Yoshida, Kazuma; Shinkawa, Keitarou; Kumagawa, Daisuke; Seguchi, Hideki

    2010-12-01

    Gold nanoparticles stabilized with thioglucose (TGlu-AuNPs), which have carboxyl groups on the particle surface as anchoring sites for covalent immobilization of biomolecules, were prepared by the chemical reduction of HAuCl4 using 1-thio-β-D-glucose as a reducing and stabilizing agent, and their application to colorimetric bioassay was demonstrated using the carbohydrate-lectin system. p-Aminophenyl α-D-mannose (Man-NH2) was covalently attached by a conventional method to the activated carboxyl groups on the TGlu-AuNPs. On addition of Con A to the Man-AuNPs, multiple binding events occurred between Con A and the mannoses immobilized on the particle surface. This Con A-induced aggregation resulted in a significant red shift in local surface plasmon resonance. The binding isotherm showed a sigmoidal curve, indicating cooperativity in the binding of Con A and the Man-AuNPs. In addition, Hill plots showed two nonequivalent binding modes, with the Kd values for high- and low-affinity binding of 11.3 and 66.5 pM, respectively, which was significantly lower than that for methyl-α-D-mannose binding to Con A. The enhanced binding affinity between Man-AuNPs and Con A involves the cluster effect of the carbohydrate groups on the AuNPs. A linear correlation curve was obtained in the range 10-100 nM (R2=0.983). The limit of detection (LOD) for Con A was 9.0 nM in aqueous buffer, which is comparable to that of other conventional methods such as ELISA. PMID:20801619

  19. A Choline Oxidase Amperometric Bioassay for the Detection of Mustard Agents Based on Screen-Printed Electrodes Modified with Prussian Blue Nanoparticles

    Directory of Open Access Journals (Sweden)

    Fabiana Arduini

    2015-02-01

    Full Text Available In this work a novel bioassay for mustard agent detection was proposed. The bioassay is based on the capability of these compounds to inhibit the enzyme choline oxidase. The enzymatic activity, which is correlated to the mustard agents, was electrochemically monitored measuring the enzymatic product, hydrogen peroxide, by means of a screen-printed electrode modified with Prussian Blue nanoparticles. Prussian Blue nanoparticles are able to electrocatalyse the hydrogen peroxide concentration reduction at low applied potential (−50 mV vs. Ag/AgCl, thus allowing the detection of the mustard agents with no electrochemical interferences. The suitability of this novel bioassay was tested with the nitrogen mustard simulant bis(2-chloroethylamine and the sulfur mustard simulants 2-chloroethyl ethyl sulfide and 2-chloroethyl phenyl sulfide. The bioassay proposed in this work allowed the detection of mustard agent simulants with good sensitivity and fast response, which are excellent premises for the development of a miniaturised sensor well suited for an alarm system in case of terrorist attacks.

  20. Development of a cell-based bioassay for phospholipase A2-triggered liposomal drug release

    DEFF Research Database (Denmark)

    Arouri, Ahmad; Trojnar, Jakub; Schmidt, Steffen;

    2015-01-01

    models, the pattern of sPLA2-assisted drug release is unknown due to the lack of a suitable bio-relevant model. We report here on the development of a novel bioluminescence living-cell-based luciferase assay for the monitoring of sPLA2-triggered release of luciferin from liposomes. To this end, we...

  1. Analytical investigation of the feasibility of sacrificial microchannel sealing for Chip-Scale Atomic Magnetometers

    OpenAIRE

    Tsujimoto, Kazuya; Hirai, Yoshikazu; Sugano, Koji; Tsuchiya, Toshiyuki; TABATA, Osamu

    2014-01-01

    An alkali metal vapor cell is a crucial component of the highly sensitive Chip Scale Atomic Magnetometers (CSAMs) that are increasingly deployed in a variety of electronic devices. Herein, we propose a novel microfabrication technique utilizing an array of microchannels at a bonded interface, to enable gas feedthrough for evacuation of unwanted gases from a vapor cell and subsequent introduction of an inert gas, followed by permanent sealing of the microchannels by reflow of a glass frit. The...

  2. Chip-scale hermetic feedthroughs for implantable bionics.

    Science.gov (United States)

    Guenther, Thomas; Dodds, Christopher W D; Lovell, Nigel H; Suaning, Gregg J

    2011-01-01

    Most implantable medical devices such as cochlear implants and visual prostheses require protection of the stimulating electronics. This is achieved by way of a hermetic feedthrough system which typically features three important attributes: biocompatibility with the human body, device hermeticity and density of feedthrough conductors. On the quest for building a visual neuroprosthesis, a high number of stimulating channels is required. This has encouraged new technologies with higher rates of production yield and further miniaturization. An Al(2)O(3) based feedthrough system has been developed comprising up to 20 platinum feedthroughs per square millimeter. Ceramics substrates are shown to have leak rates below 1 × 10(-12) atm × cc/s, thus exceeding the resolution limits of most commercially available leak detectors. A sheet resistance of 0.05 Ω can be achieved. This paper describes the design, fabrication process and hermeticity testing of high density feedthroughs for use in neuroprosthetic implants. PMID:22255880

  3. Chip-scale hermetic feedthroughs for implantable bionics.

    Science.gov (United States)

    Guenther, Thomas; Dodds, Christopher W D; Lovell, Nigel H; Suaning, Gregg J

    2011-01-01

    Most implantable medical devices such as cochlear implants and visual prostheses require protection of the stimulating electronics. This is achieved by way of a hermetic feedthrough system which typically features three important attributes: biocompatibility with the human body, device hermeticity and density of feedthrough conductors. On the quest for building a visual neuroprosthesis, a high number of stimulating channels is required. This has encouraged new technologies with higher rates of production yield and further miniaturization. An Al(2)O(3) based feedthrough system has been developed comprising up to 20 platinum feedthroughs per square millimeter. Ceramics substrates are shown to have leak rates below 1 × 10(-12) atm × cc/s, thus exceeding the resolution limits of most commercially available leak detectors. A sheet resistance of 0.05 Ω can be achieved. This paper describes the design, fabrication process and hermeticity testing of high density feedthroughs for use in neuroprosthetic implants.

  4. Chip scale low dimensional materials: optoelectronics & nonlinear optics

    Science.gov (United States)

    Gu, Tingyi

    The CMOS foundry infrastructure enables integration of high density, high performance optical transceivers. We developed integrated devices that assemble resonators, waveguide, tapered couplers, pn junction and electrodes. Not only the volume standard manufacture in silicon foundry is promising to low-lost optical components operating at IR and mid-IR range, it also provides a robust platform for revealing new physical phenomenon. The thesis starts from comparison between photonic crystal and micro-ring resonators based on chip routers, showing photonic crystal switches have small footprint, consume low operation power, but its higher linear loss may require extra energy for signal amplification. Different designs are employed in their implementation in optical signal routing on chip. The second part of chapter 2 reviews the graphene based optoelectronic devices, such as modulators, lasers, switches and detectors, potential for group IV optoelectronic integrated circuits (OEIC). In chapter 3, the highly efficient thermal optic control could act as on-chip switches and (transmittance) tunable filters. Local temperature tuning compensates the wavelength differences between two resonances, and separate electrode is used for fine tuning of optical pathways between two resonators. In frequency domain, the two cavity system also serves as an optical analogue of Autler-Towns splitting, where the cavity-cavity resonance detuning is controlled by the length of pathway (phase) between them. The high thermal sensitivity of cavity resonance also effectively reflects the heat distribution around the nanoheaters, and thus derives the thermal conductivity in the planar porous suspended silicon membrane. Chapter 4 & 5 analyze graphene-silicon photonic crystal cavities with high Q and small mode volume. With negligible nonlinear response to the milliwatt laser excitation, the monolithic silicon PhC turns into highly nonlinear after transferring the single layer graphene with

  5. Towards Chip Scale Liquid Chromatography and High Throughput Immunosensing

    Energy Technology Data Exchange (ETDEWEB)

    Ni, J.

    2000-09-21

    This work describes several research projects aimed towards developing new instruments and novel methods for high throughput chemical and biological analysis. Approaches are taken in two directions. The first direction takes advantage of well-established semiconductor fabrication techniques and applies them to miniaturize instruments that are workhorses in analytical laboratories. Specifically, the first part of this work focused on the development of micropumps and microvalves for controlled fluid delivery. The mechanism of these micropumps and microvalves relies on the electrochemically-induced surface tension change at a mercury/electrolyte interface. A miniaturized flow injection analysis device was integrated and flow injection analyses were demonstrated. In the second part of this work, microfluidic chips were also designed, fabricated, and tested. Separations of two fluorescent dyes were demonstrated in microfabricated channels, based on an open-tubular liquid chromatography (OT LC) or an electrochemically-modulated liquid chromatography (EMLC) format. A reduction in instrument size can potentially increase analysis speed, and allow exceedingly small amounts of sample to be analyzed under diverse separation conditions. The second direction explores the surface enhanced Raman spectroscopy (SERS) as a signal transduction method for immunoassay analysis. It takes advantage of the improved detection sensitivity as a result of surface enhancement on colloidal gold, the narrow width of Raman band, and the stability of Raman scattering signals to distinguish several different species simultaneously without exploiting spatially-separated addresses on a biochip. By labeling gold nanoparticles with different Raman reporters in conjunction with different detection antibodies, a simultaneous detection of a dual-analyte immunoassay was demonstrated. Using this scheme for quantitative analysis was also studied and preliminary dose-response curves from an immunoassay of a

  6. Photonic-crystal lasers on silicon for chip-scale optical interconnects

    Science.gov (United States)

    Takeda, Koji; Fujii, Takuro; Shinya, Akihiko; Kuramochi, Eiichi; Notomi, Masaya; Hasebe, Koichi; Kakitsuka, Takaaki; Matsuo, Shinji

    2016-03-01

    Optical interconnects are expected to reduce the power consumption of ICT instruments. To realize chip-to-chip or chip-scale optical interconnects, it is essential to fabricate semiconductor lasers with a smaller energy cost. In this context, we are developing lambda-scale embedded active-region photonic-crystal (LEAP) lasers as light sources for chip-scale optical interconnects. We demonstrated the first continuous-wave (CW) operation of LEAP lasers in 2012 and reported a record low threshold current and energy cost of 4.8 μA and 4.4 fJ/bit at 10 Gbit/s in 2013. We have also integrated photonic crystal photodetectors on the same InP chip and demonstrated waveform transfer along 500-μm-long waveguides. Although LEAP lasers exhibit excellent performance, they have to be integrated on Si wafers for use as light sources for chip-scale optical interconnects. In this paper, we give a brief overview of our LEAP lasers on InP and report our recent progress in fabricating them on Si. We bonded the InP wafers with quantum-well gain layers directly on thermally oxidized Si wafers and performed all process steps on the Si wafer, including high-temperature regrowth. After this process modification, we again achieved CW operation and obtained a threshold current of 57 μA with a maximum output power of more than 3.5 μW at the output waveguides. An output light was successfully guided through 500 × 250-nm InP waveguides.

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

    Directory of Open Access Journals (Sweden)

    Yeu-Long Jiang

    2013-08-01

    Full Text Available 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.

  8. Virtual screening of bioassay data

    Directory of Open Access Journals (Sweden)

    Schierz Amanda C

    2009-12-01

    Full Text Available Abstract Background There are three main problems associated with the virtual screening of bioassay data. The first is access to freely-available curated data, the second is the number of false positives that occur in the physical primary screening process, and finally the data is highly-imbalanced with a low ratio of Active compounds to Inactive compounds. This paper first discusses these three problems and then a selection of Weka cost-sensitive classifiers (Naive Bayes, SVM, C4.5 and Random Forest are applied to a variety of bioassay datasets. Results Pharmaceutical bioassay data is not readily available to the academic community. The data held at PubChem is not curated and there is a lack of detailed cross-referencing between Primary and Confirmatory screening assays. With regard to the number of false positives that occur in the primary screening process, the analysis carried out has been shallow due to the lack of cross-referencing mentioned above. In six cases found, the average percentage of false positives from the High-Throughput Primary screen is quite high at 64%. For the cost-sensitive classification, Weka's implementations of the Support Vector Machine and C4.5 decision tree learner have performed relatively well. It was also found, that the setting of the Weka cost matrix is dependent on the base classifier used and not solely on the ratio of class imbalance. Conclusions Understandably, pharmaceutical data is hard to obtain. However, it would be beneficial to both the pharmaceutical industry and to academics for curated primary screening and corresponding confirmatory data to be provided. Two benefits could be gained by employing virtual screening techniques to bioassay data. First, by reducing the search space of compounds to be screened and secondly, by analysing the false positives that occur in the primary screening process, the technology may be improved. The number of false positives arising from primary screening leads to

  9. Stabilized chip-scale Kerr frequency comb via a high-Q reference photonic microresonator

    Science.gov (United States)

    Lim, Jinkang; Huang, Shu-Wei; Vinod, Abhinav K.; Mortazavian, Parastou; Yu, Mingbin; Kwong, Dim-Lee; Savchenkov, Anatoliy A.; Matsko, Andrey B.; Maleki, Lute; Wong, Chee Wei

    2016-08-01

    We stabilize a chip-scale Si3N4 phase-locked Kerr frequency comb via locking the pump laser to an independent stable high-Q reference microresonator and locking the comb spacing to an external microwave oscillator. In this comb, the pump laser shift induces negligible impact on the comb spacing change. This scheme is a step towards miniaturization of the stabilized Kerr comb system as the microresonator reference can potentially be integrated on-chip. Fractional instability of the optical harmonics of the stabilized comb is limited by the microwave oscillator used for comb spacing lock below 1 s averaging time and coincides with the pump laser drift in the long term.

  10. A stabilized chip-scale Kerr frequency comb via a high-Q reference photonic microresonator

    CERN Document Server

    Lim, Jinkang; Vinod, Abhinav K; Mortazavian, Parastou; Yu, Mingbin; Kwong, Dim-Lee; Savchenkov, Anatoliy A; Matsko, Andrey B; Maleki, Lute; Wong, Chee Wei

    2016-01-01

    We stabilize a chip-scale Si3N4 phase-locked Kerr frequency comb via locking the pump laser to an independent stable high-Q reference microresonator and locking the comb spacing to an external microwave oscillator. In this comb, the pump laser shift induces negligible impact on the comb spacing change. This scheme is a step towards miniaturization of the stabilized Kerr comb system as the microresonator reference can potentially be integrated on-chip. Fractional instability of the optical harmonics of the stabilized comb is limited by the microwave oscillator used for comb spacing lock below 1 s averaging time and coincides with the pump laser drift in the long term.

  11. Sacrificial Microchannel Sealing by Glass-Frit Reflow for Chip Scale Atomic Magnetometer

    Science.gov (United States)

    Tsujimoto, Kazuya; Hirai, Yoshikazu; Sugano, Koji; Tsuchiya, Toshiyuki; Tabata, Osamu

    A novel sealing technique using sacrificial microchannels was proposed for atmosphere control in a micromachined alkali gas-filled cell for a chip scale atomic magnetometer. The microchannels act as feedthrough connecting the cell to outside atmosphere during evacuation and gas-filling steps, and eventually they are sealed by glass-frit reflow. Si microchannel dedicated as a sacrificial microchannel was proposed and its feasibility was successfully demonstrated by experiments. The simulation results clarified the glass-frit reflow characteristics and its dependence on cross-sectional shape of the microchannel. Hermeticity of the proposed sealing technique of less than 10-12Pa·m3/s leak rate was verified by a high resolution helium leak test.

  12. Assessing the ecological long-term impact of wastewater irrigation on soil and water based on bioassays and chemical analyses.

    Science.gov (United States)

    Richter, Elisabeth; Hecht, Fabian; Schnellbacher, Nadine; Ternes, Thomas A; Wick, Arne; Wode, Florian; Coors, Anja

    2015-11-01

    The reuse of treated wastewater for irrigation and groundwater recharge can counteract water scarcity and reduce pollution of surface waters, but assessing its environmental risk should likewise consider effects associated to the soil. The present study therefore aimed at determining the impact of wastewater irrigation on the habitat quality of water after soil passage and of soil after percolation by applying bioassays and chemical analysis. Lab-scale columns of four different soils encompassing standard European soil and three field soils of varying characteristics and pre-contamination were continuously percolated with treated wastewater to simulate long-term irrigation. Wastewater and its percolates were tested for immobilization of Daphnia magna and growth inhibition of green algae (Pseudokirchneriella subcapitata) and water lentils (Lemna minor). The observed phytotoxicity of the treated wastewater was mostly reduced by soil passage, but in some percolates also increased for green algae. Chemical analysis covering an extensive set of wastewater-born organic pollutants demonstrated that many of them were considerably reduced by soil passage, particularly through peaty soils. Taken together, these results indicated that wastewater-born phytotoxic substances may be removed by soil passage, while existing soil pollutants (e.g. metals) may leach and impair percolate quality. Soils with and without wastewater irrigation were tested for growth of plants (Avena sativa, Brassica napus) and soil bacteria (Arthrobacter globiformis) and reproduction of collembolans (Folsomia candida) and oligochaetes (Enchytraeus crypticus, Eisenia fetida). The habitat quality of the standard and two field soils appeared to be deteriorated by wastewater percolation for at least one organism (enchytraeids, plants or bacteria), while for two pre-contaminated field soils it also was improved (for plants and/or enchytraeids). Wastewater percolation did not seem to raise soil concentrations

  13. A broadband chip-scale optical frequency synthesizer at 2.7 × 10−16 relative uncertainty

    OpenAIRE

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H.; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-01-01

    Optical frequency combs—coherent light sources that connect optical frequencies with microwave oscillations—have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale ...

  14. Validation and reliability assessment of board level drop test of chip-scale-packaging

    Science.gov (United States)

    Hung, Tuan-Yu; Chou, Chan-Yen; Yew, Ming-Chih; Chiang, Kuo-Ning

    2008-11-01

    The main objective of this study is to develop a stress-buffer-improved package that is subjected to a board level drop test under a specific-G impact level. In this regard, both the drop test experiment and the ANSYS/LS-DYNA simulations are carried out. Several studies have shown that the solder joints having the brittle intermetallic compound (IMC) layers within the wafer level chip scale packaging (WLCSP) are the weakest part. For the most part, this is due to the large relative motion occurring between the board and the chip. In addition, the stress buffer layer exhibiting a relatively large elongation which reduces the impact on the solder balls. Meanwhile, the novel stress-buffer-improve package's failure mode is different from the convention WLCSP structure which shifts to the trace damage of the chip side. The leading concern between the solder ball and trace damage is the critical region where failure occurred owing to the stress concentration effect. During the drop test experiment, the proposed stress-buffer-improved package is able to survive over 100 drops (most packages survived at above 200 drops). Hence, this drop performance very much surpasses the Joint Electron Device Engineering Council (JEDEC) criterion (drop number is 30 times). Nevertheless, the metal traces which are embedded in the stress buffer layer suffered relatively larger deformation. Generally, the stress concentration occurs at a single position, much like the trace/pad connecting junction in the analysis of detailed stress-buffer-improved package. Finally, the predict result in finite element (FE) analysis is similar to the broken metal trace's failure analysis in the drop test experiment.

  15. Rapid screening of aquatic toxicity of several metal-based nanoparticles using the MetPLATE Trade-Mark-Sign bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Lok R.; Silva, Thilini [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States); Dubey, Brajesh, E-mail: bdubey@uoguelph.ca [Environmental Engineering, School of Engineering, University of Guelph, 50 Stone Road East, Guelph, Ontario (Canada); El Badawy, Amro M. [Department of Civil and Environmental Engineering, University of Cincinnati, Cincinnati, OH (United States); Tolaymat, Thabet M. [USEPA, Office of Research and Development, National Risk Management Laboratory, 26 West Martin Luther King Drive, Cincinnati, OH 45224 (United States); Scheuerman, Phillip R. [Department of Environmental Health, College of Public Health, East Tennessee State University, Johnson City, TN 37614 (United States)

    2012-06-01

    Current understanding of potential toxicity of engineered nanomaterials to aquatic microorganisms is limited for risk assessment and management. Here we evaluate if the MetPLATE Trade-Mark-Sign test can be used as an effective and rapid screening tool to test for potential aquatic toxicity of various metal-based nanoparticles (NPs). The MetPLATE bioassay is a heavy metal sensitive test based on {beta}-galactosidase activity in Escherichia coli. Five different types of metal-based NPs were screened for toxicity: (1) citrate coated nAg (Citrate-nanosilver), (2) polyvinylpyrrolidone coated nAg (PVP-nAg), (3) uncoated nZnO, (4) uncoated nTiO{sub 2} and (5) 1-Octadecylamine coated CdSe Quantum Dots (CdSe QDs); and compared with their corresponding ionic salt toxicity. Citrate-nAg was further fractionated into clean Citrate-nAg, unclean Citrate-nAg and permeate using a tangential flow filtration (TFF) system to eliminate residual ions and impurities from the stock Citrate-nAg suspension and also to differentiate between ionic- versus nano-specific toxicity. Our results showed that nAg, nZnO and CdSe QDs were less toxic than their corresponding ionic salts tested, while nano- or ionic form of TiO{sub 2} was not toxic as high as 2.5 g L{sup -1} to the MetPLATE Trade-Mark-Sign bacteria. Although coating-dependent toxicity was noticeable between two types of Ag NPs evaluated, particle size and surface charge were not adequate to explain the observed toxicity; hence, the toxicity appeared to be material-specific. Overall, the toxicity followed the trend: CdCl{sub 2} > AgNO{sub 3} > PVP-nAg > unclean Citrate-nAg > clean Citrate-nAg > ZnSO{sub 4} > nZnO > CdSe QDs > nTiO{sub 2}/TiO{sub 2}. These results indicate that an evaluation of {beta}-galactosidase inhibition in MetPLATE Trade-Mark-Sign E. coli can be an important consideration for rapid screening of metal-based NP toxicity, and should facilitate ecological risk assessment of these emerging contaminants. - Highlights

  16. Comparison of two screening bioassays, based on the frog sciatic nerve and yeast cells, for the assessment of herbicide toxicity.

    Science.gov (United States)

    Papaefthimiou, Chrisovalantis; Cabral, Maria de Guadalupe; Mixailidou, Christina; Viegas, Cristina A; Sá-Correia, Isabel; Theophilidis, George

    2004-05-01

    Two different test systems, one based on the isolated sciatic nerve of an amphibian and the other on a microbial eukaryote, were used for the assessment of herbicide toxicity. More specifically, we determined the deleterious effects of increasing concentrations of herbicides of different chemical classes (phenoxyacetic acids, triazines, and acetamides), and of 2,4-dichlorophenol (2,4-DCP), a degradation product of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D), on electrophysiological parameters and the vitality of the axons of the isolated sciatic nerve of the frog (Rana ridibunda) and on the growth curve of the yeast Saccharomyces cerevisiae based on microtiter plate susceptibility assays. The no-observed-effect-concentration (NOEC), defined as the maximum concentration of the tested compound that has no effect on these biological parameters, was estimated. In spite of the different methodological approaches and biological systems compared, the NOEC values were identical and correlated with the lipophilicity of the tested compounds. The relative toxicity established here, 2,4-DCP > alachlor, metolachlor > metribuzin > 2,4-D, 2-methyl-4-chlorophenoxyacetic acid (MCPA), correlates with the toxicity indexes reported in the literature for freshwater organisms. Based on these results, we suggest that the relatively simple, rapid, and low-cost test systems examined here may be of interest as alternative or complementary tests for toxicological assessment of herbicides. PMID:15180372

  17. Giant Magnetoresistive Sensors and Magnetic Labels for Chip-Scale Detection of Immunosorbent Assays

    Energy Technology Data Exchange (ETDEWEB)

    Millen, Rachel Lora [Iowa State Univ., Ames, IA (United States)

    2005-01-01

    The combination of giant magnetoresistive sensors, magnetic labeling strategies, and biomolecule detection is just beginning to be explored. New readout methods and assay formats are necessary for biomolecules detection to flourish. The work presented in this dissertation describes steps toward the creation of a novel detection method for bioassays utilizing giant magnetoresistive sensors as the readout method. The introduction section contains a brief review of some of the current methods of bioassay readout. The theoretical underpinnings of the giant magnetoresistive effect are also discussed. Finally, the more prominent types of giant magnetoresistive sensors are described, as well as their complicated fabrication. Four data chapters follow the introduction; each chapter is presented as a separate manuscript, either already published or soon to be submitted. Chapter 1 presents research efforts toward the production of a bioassay on the surface of a gold-modified GMR sensor. The testing of this methodology involved the capture of goat a-mouse-coated magnetic nanoparticles on the mouse IgG-modified gold surface. The second, third and fourth chapters describe the utilization of a self-referenced sample stick for scanning across the GMR sensor. The sample stick consisted of alternating magnetic reference and bioactive gold addresses. Chapter 2 is concerned with the characterization of both the scanning readout method and the binding and detection of streptavidin-coated magnetic particles to a biotinylated surface. Chapter 3 advances the sample stick readout with the use of the system for detection of a sandwich immunoassay with rabbit IgG proteins. Finally, simultaneous detection of three IgG proteins is demonstrated in Chapter 4. The dissertation is concluded with a brief summary of the research presented and a discussion of the possible future applications and direction of this work.

  18. A cell-based fascin bioassay identifies compounds with potential anti-metastasis or cognition-enhancing functions

    Directory of Open Access Journals (Sweden)

    Robert Kraft

    2013-01-01

    The actin-bundling protein fascin is a key mediator of tumor invasion and metastasis and its activity drives filopodia formation, cell-shape changes and cell migration. Small-molecule inhibitors of fascin block tumor metastasis in animal models. Conversely, fascin deficiency might underlie the pathogenesis of some developmental brain disorders. To identify fascin-pathway modulators we devised a cell-based assay for fascin function and used it in a bidirectional drug screen. The screen utilized cultured fascin-deficient mutant Drosophila neurons, whose neurite arbors manifest the ‘filagree’ phenotype. Taking a repurposing approach, we screened a library of 1040 known compounds, many of them FDA-approved drugs, for filagree modifiers. Based on scaffold distribution, molecular-fingerprint similarities, and chemical-space distribution, this library has high structural diversity, supporting its utility as a screening tool. We identified 34 fascin-pathway blockers (with potential anti-metastasis activity and 48 fascin-pathway enhancers (with potential cognitive-enhancer activity. The structural diversity of the active compounds suggests multiple molecular targets. Comparisons of active and inactive compounds provided preliminary structure-activity relationship information. The screen also revealed diverse neurotoxic effects of other drugs, notably the ‘beads-on-a-string’ defect, which is induced solely by statins. Statin-induced neurotoxicity is enhanced by fascin deficiency. In summary, we provide evidence that primary neuron culture using a genetic model organism can be valuable for early-stage drug discovery and developmental neurotoxicity testing. Furthermore, we propose that, given an appropriate assay for target-pathway function, bidirectional screening for brain-development disorders and invasive cancers represents an efficient, multipurpose strategy for drug discovery.

  19. Detection of Tetrodotoxins in Puffer Fish by a Self-Assembled Monolayer-Based Immunoassay and Comparison with Surface Plasmon Resonance, LC-MS/MS, and Mouse Bioassay.

    Science.gov (United States)

    Reverté, Laia; de la Iglesia, Pablo; del Río, Vanessa; Campbell, Katrina; Elliott, Christopher T; Kawatsu, Kentaro; Katikou, Panagiota; Diogène, Jorge; Campàs, Mònica

    2015-11-01

    The increasing occurrence of puffer fish containing tetrodotoxin (TTX) in the Mediterranean could represent a major food safety risk for European consumers and threaten the fishing industry. The work presented herein describes the development of a new enzyme linked immunosorbent assay (mELISA) based on the immobilization of TTX through dithiol monolayers self-assembled on maleimide plates, which provides an ordered and oriented antigen immobilization and favors the antigen-antibody affinity interaction. The mELISA was found to have a limit of detection (LOD) of TTX of 0.23 mg/kg of puffer fish matrix. The mELISA and a surface plasmon resonance (SPR) immunosensor previously developed were employed to establish the cross-reactivity factors (CRFs) of 5,6,11-trideoxy-TTX, 5,11-deoxy-TTX, 11-nor-TTX-6-ol, and 5,6,11-trideoxy-4-anhydro-TTX, as well as to determine TTX equivalent contents in puffer fish samples. Results obtained by both immunochemical tools were correlated (R(2) = 0.977). The puffer fish samples were also analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the corresponding CRFs were applied to the individual TTX contents. Results provided by the immunochemical tools, when compared with those obtained by LC-MS/MS, showed a good degree of correlation (R(2) = 0.991 and 0.979 for mELISA and SPR, respectively). The mouse bioassay (MBA) slightly overestimated the CRF adjusted TTX content of samples when compared with the data obtained from the other techniques. The mELISA has been demonstrated to be fit for the purpose for screening samples in monitoring programs and in research activities.

  20. Detection of Tetrodotoxins in Puffer Fish by a Self-Assembled Monolayer-Based Immunoassay and Comparison with Surface Plasmon Resonance, LC-MS/MS, and Mouse Bioassay.

    Science.gov (United States)

    Reverté, Laia; de la Iglesia, Pablo; del Río, Vanessa; Campbell, Katrina; Elliott, Christopher T; Kawatsu, Kentaro; Katikou, Panagiota; Diogène, Jorge; Campàs, Mònica

    2015-11-01

    The increasing occurrence of puffer fish containing tetrodotoxin (TTX) in the Mediterranean could represent a major food safety risk for European consumers and threaten the fishing industry. The work presented herein describes the development of a new enzyme linked immunosorbent assay (mELISA) based on the immobilization of TTX through dithiol monolayers self-assembled on maleimide plates, which provides an ordered and oriented antigen immobilization and favors the antigen-antibody affinity interaction. The mELISA was found to have a limit of detection (LOD) of TTX of 0.23 mg/kg of puffer fish matrix. The mELISA and a surface plasmon resonance (SPR) immunosensor previously developed were employed to establish the cross-reactivity factors (CRFs) of 5,6,11-trideoxy-TTX, 5,11-deoxy-TTX, 11-nor-TTX-6-ol, and 5,6,11-trideoxy-4-anhydro-TTX, as well as to determine TTX equivalent contents in puffer fish samples. Results obtained by both immunochemical tools were correlated (R(2) = 0.977). The puffer fish samples were also analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS), and the corresponding CRFs were applied to the individual TTX contents. Results provided by the immunochemical tools, when compared with those obtained by LC-MS/MS, showed a good degree of correlation (R(2) = 0.991 and 0.979 for mELISA and SPR, respectively). The mouse bioassay (MBA) slightly overestimated the CRF adjusted TTX content of samples when compared with the data obtained from the other techniques. The mELISA has been demonstrated to be fit for the purpose for screening samples in monitoring programs and in research activities. PMID:26424329

  1. Bioassay Phantoms Using Medical Images and Computer Aided Manufacturing

    International Nuclear Information System (INIS)

    A radiation bioassay program relies on a set of standard human phantoms to calibrate and assess radioactivity levels inside a human body for radiation protection and nuclear medicine imaging purposes. However, the methodologies in the development and application of anthropomorphic phantoms, both physical and computational, had mostly remained the same for the past 40 years. We herein propose a 3-year research project to develop medical image-based physical and computational phantoms specifically for radiation bioassay applications involving internally deposited radionuclides. The broad, long-term objective of this research was to set the foundation for a systematic paradigm shift away from the anatomically crude phantoms in existence today to realistic and ultimately individual-specific bioassay methodologies. This long-term objective is expected to impact all areas of radiation bioassay involving nuclear power plants, U.S. DOE laboratories, and nuclear medicine clinics.

  2. Bioassay Phantoms Using Medical Images and Computer Aided Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Dr. X. Geroge Xu

    2011-01-28

    A radiation bioassay program relies on a set of standard human phantoms to calibrate and assess radioactivity levels inside a human body for radiation protection and nuclear medicine imaging purposes. However, the methodologies in the development and application of anthropomorphic phantoms, both physical and computational, had mostly remained the same for the past 40 years. We herein propose a 3-year research project to develop medical image-based physical and computational phantoms specifically for radiation bioassay applications involving internally deposited radionuclides. The broad, long-term objective of this research was to set the foundation for a systematic paradigm shift away from the anatomically crude phantoms in existence today to realistic and ultimately individual-specific bioassay methodologies. This long-term objective is expected to impact all areas of radiation bioassay involving nuclear power plants, U.S. DOE laboratories, and nuclear medicine clinics.

  3. Microwave-accelerated bioassay technique for rapid and quantitative detection of biological and environmental samples.

    Science.gov (United States)

    Mohammed, Muzaffer; Syed, Maleeha F; Aslan, Kadir

    2016-01-15

    Quantitative detection of molecules of interest from biological and environmental samples in a rapid manner, particularly with a relevant concentration range, is imperative to the timely assessment of human diseases and environmental issues. In this work, we employed the microwave-accelerated bioassay (MAB) technique, which is based on the combined use of circular bioassay platforms and microwave heating, for rapid and quantitative detection of Glial Fibrillary Acidic Protein (GFAP) and Shiga like toxin (STX 1). The proof-of-principle use of the MAB technique with the circular bioassay platforms for the rapid detection of GFAP in buffer based on colorimetric and fluorescence readouts was demonstrated with a 900W kitchen microwave. We also employed the MAB technique with a new microwave system (called the iCrystal system) for the detection of GFAP from mice with brain injuries and STX 1 from a city water stream. Control bioassays included the commercially available gold standard bioassay kits run at room temperature. Our results show that the lower limit of detection (LLOD) of the colorimetric and fluorescence based bioassays for GFAP was decreased by ~1000 times using the MAB technique and our circular bioassay platforms as compared to the commercially available bioassay kits. The overall bioassay time for GFAP and STX 1 was reduced from 4h using commercially available bioassay kits to 10min using the MAB technique.

  4. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty.

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-04-01

    Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography.

  5. A broadband chip-scale optical frequency synthesizer at 2.7 × 10(-16) relative uncertainty.

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-04-01

    Optical frequency combs-coherent light sources that connect optical frequencies with microwave oscillations-have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb's two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of [Formula: see text]. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10(-16), heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography. PMID:27152341

  6. A broadband chip-scale optical frequency synthesizer at 2.7 × 10−16 relative uncertainty

    Science.gov (United States)

    Huang, Shu-Wei; Yang, Jinghui; Yu, Mingbin; McGuyer, Bart H.; Kwong, Dim-Lee; Zelevinsky, Tanya; Wong, Chee Wei

    2016-01-01

    Optical frequency combs—coherent light sources that connect optical frequencies with microwave oscillations—have become the enabling tool for precision spectroscopy, optical clockwork, and attosecond physics over the past decades. Current benchmark systems are self-referenced femtosecond mode-locked lasers, but Kerr nonlinear dynamics in high-Q solid-state microresonators has recently demonstrated promising features as alternative platforms. The advance not only fosters studies of chip-scale frequency metrology but also extends the realm of optical frequency combs. We report the full stabilization of chip-scale optical frequency combs. The microcomb’s two degrees of freedom, one of the comb lines and the native 18-GHz comb spacing, are simultaneously phase-locked to known optical and microwave references. Active comb spacing stabilization improves long-term stability by six orders of magnitude, reaching a record instrument-limited residual instability of 3.6mHz/τ. Comparing 46 nitride frequency comb lines with a fiber laser frequency comb, we demonstrate the unprecedented microcomb tooth-to-tooth relative frequency uncertainty down to 50 mHz and 2.7 × 10−16, heralding novel solid-state applications in precision spectroscopy, coherent communications, and astronomical spectrography. PMID:27152341

  7. UNIFYING SCALER FOR BIOASSAY TESTS

    Science.gov (United States)

    An extensive set of interlaboratory root bioassay data was unified using centroids of individual tests as scalers. It is shown that the dose response obeys a first order differential equation with the constant of the equation related to the sensitivity of the dose response relati...

  8. Characterization and modeling of two-phase heat transfer in chip-scale non-uniformly heated microgap channels

    Science.gov (United States)

    Ali, Ihab A.

    A chip-scale, non-uniformly heated microgap channel, 100 micron to 500 micron in height with dielectric fluid HFE-7100 providing direct single- and two-phase liquid cooling for a thermal test chip with localized heat flux reaching 100 W/cm2, is experimentally characterized and numerically modeled. Single-phase heat transfer and hydraulic characterization is performed to establish the single-phase baseline performance of the microgap channel and to validate the mesh-intensive CFD numerical model developed for the test channel. Convective heat transfer coefficients for HFE-7100 flowing in a 100-micron microgap channel reached 9 kW/m2K at 6.5 m/s fluid velocity. Despite the highly non-uniform boundary conditions imposed on the microgap channel, CFD model simulation gave excellent agreement with the experimental data (to within 5%), while the discrepancy with the predictions of the classical, "ideal" channel correlations in the literature reached 20%. A detailed investigation of two-phase heat transfer in non-ideal micro gap channels, with developing flow and significant non-uniformities in heat generation, was performed. Significant temperature non-uniformities were observed with non-uniform heating, where the wall temperature gradient exceeded 30°C with a heat flux gradient of 3-30 W/cm2, for the quadrant-die heating pattern compared to a 20°C gradient and 7-14 W/cm2 heat flux gradient for the uniform heating pattern, at 25W heat and 1500 kg/m2s mass flux. Using an inverse computation technique for determining the heat flow into the wetted microgap channel, average wall heat transfer coefficients were found to vary in a complex fashion with channel height, flow rate, heat flux, and heating pattern and to typically display an inverse parabolic segment of a previously observed M-shaped variation with quality, for two-phase thermal transport. Examination of heat transfer coefficients sorted by flow regimes yielded an overall agreement of 31% between predictions of the

  9. 77 FR 14837 - Bioassay at Uranium Mills

    Science.gov (United States)

    2012-03-13

    ... COMMISSION Bioassay at Uranium Mills AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... for public comment draft regulatory guide (DG), DG-8051, ``Bioassay at Uranium Mills.'' This guide describes a bioassay program acceptable to the NRC staff for uranium mills and applicable portions...

  10. Comparison of five bioassay techniques for assessing sediment-bound contaminants

    OpenAIRE

    Ahlf, Wolfgang; Calmano, Wolfgang; Erhard, Judith; Förstner, Ulrich

    1989-01-01

    Biological response could not be predicted based on chemical concentration of the sediment contaminants. Bioassays integrate the response of test organisms to contaminants and nutrients. Comparative results of five acute bioassays indicated that Neubauer phytoassay was the most sensitive. The mircobial biomass and algal growth tests indicated a response to the availability of contaminants and nutrients. These results suggest the usefulness of a diversity of bioassays in toxicity testing of se...

  11. Individual Radiological Protection Monitoring of Utrok Atoll Residents Based on Whole Body Counting of Cesium-137 (137Cs) and Plutonium Bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Hamilton, T; Kehl, S; Brown, T; Martinelli, R; Hickman, D; Jue, T; Tumey, S; Langston, R

    2007-06-08

    This report contains individual radiological protection surveillance data developed during 2006 for adult members of a select group of families living on Utrok Atoll. These Group I volunteers all underwent a whole-body count to determine levels of internally deposited cesium-137 ({sup 137}Cs) and supplied a bioassay sample for analysis of plutonium isotopes. Measurement data were obtained and the results compared with an equivalent set of measurement data for {sup 137}Cs and plutonium isotopes from a second group of adult volunteers (Group II) who were long-term residents of Utrok Atoll. For the purposes of this comparison, Group II volunteers were considered representative of the general population on Utrok Atoll. The general aim of the study was to determine residual systemic burdens of fallout radionuclides in each volunteer group, develop data in response to addressing some specific concerns about the preferential uptake and potential health consequences of residual fallout radionuclides in Group I volunteers, and generally provide some perspective on the significance of radiation doses delivered to volunteers (and the general Utrok Atoll resident population) in terms of radiological protection standards and health risks. Based on dose estimates from measurements of internally deposited {sup 137}Cs and plutonium isotopes, the data and information developed in this report clearly show that neither volunteer group has acquired levels of internally deposited fallout radionuclides specific to nuclear weapons testing in the Marshall Islands that are likely to have any consequence on human health. Moreover, the dose estimates are well below radiological protection standards as prescribed by U.S. regulators and international agencies, and are very small when compared to doses from natural sources of radiation in the Marshall Islands and the threshold where radiation health effects could be either medically diagnosed in an individual or epidemiologically discerned in a

  12. Herbicide impact on Hormosira banksii gametes measured by fluorescence and germination bioassays

    International Nuclear Information System (INIS)

    The innovative bioassay described here involves chlorophyll a fluorescence measurements of gametes from the macroalgae, Hormosira banksii, where gametes (eggs) were exposed to Diuron, Irgarol and Bromacil. Response was assessed as percent inhibition from control of effective quantum yield (ΔF/Fm') of photosystem II, herein referred to as % PSII Inhibition. This was measured with the dual-channelled pulse amplitude modulated (PAM) fluorometer, ToxY-PAM. The fluorescence bioassay was run simultaneously with an established H. banksii germination bioassay to compare sensitivity, precision, and time-to-result. The fluorescence bioassay gave highly sensitive results evidenced by EC5s (% PSII Inhibition) for Diuron, Irgarol and Bromacil being three, four and three orders of magnitude (respectively) lower than EC5s generated from the germination bioassays. Precision of the fluorescence bioassay was demonstrated with low coefficient of variations (<30%) for all three toxicants. With regard to time, the fluorescence bioassay gave results within 6 h, as opposed to more than 50 h for the germination bioassay. - Chlorophyll a fluorescence measurements form the basis of a macroalgal bioassay with many advantages over germination-based methods

  13. Urine sample collection protocols for bioassay samples

    Energy Technology Data Exchange (ETDEWEB)

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject`s body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  14. Urine sample collection protocols for bioassay samples

    Energy Technology Data Exchange (ETDEWEB)

    MacLellan, J.A.; McFadden, K.M.

    1992-11-01

    In vitro radiobioassay analyses are used to measure the amount of radioactive material excreted by personnel exposed to the potential intake of radioactive material. The analytical results are then used with various metabolic models to estimate the amount of radioactive material in the subject's body and the original intake of radioactive material. Proper application of these metabolic models requires knowledge of the excretion period. It is normal practice to design the bioassay program based on a 24-hour excretion sample. The Hanford bioassay program simulates a total 24-hour urine excretion sample with urine collection periods lasting from one-half hour before retiring to one-half hour after rising on two consecutive days. Urine passed during the specified periods is collected in three 1-L bottles. Because the daily excretion volume given in Publication 23 of the International Commission on Radiological Protection (ICRP 1975, p. 354) for Reference Man is 1.4 L, it was proposed to use only two 1-L bottles as a cost-saving measure. This raised the broader question of what should be the design capacity of a 24-hour urine sample kit.

  15. Signal Amplification of Bioassay Using Zinc Nanomaterials

    Science.gov (United States)

    Cowles, Chad L.

    An emerging trend in the analytical detection sciences is the employment of nanomaterials for bioassay signal transduction to identify analytes critical to public health. These nanomaterials have been specifically investigated for applications which require identification of trace levels of cells, proteins, or other molecules that can have broad ranging impacts to human health in fields such as clinical diagnostics, environmental monitoring, food and drink control, and the prevention of bioterrorism. Oftentimes these nanoparticle-based signal transduction or amplification approaches offer distinct advantages over conventional methods such as increased sensitivity, rapidity, or stability. The biological application of nanoparticles however, does suffer from drawbacks that have limited more widespread adoption of these techniques. Some of these drawbacks are, high cost and toxicity, arduous synthesis methods, functionalization and bioconjugation challenges, and laboratory disposal and environmental hazard issues, all of which have impeded the progression of this technology in some way or another. This work aims at developing novel techniques that offer solutions to a number of these hurdles through the development of new nanoparticle-based signal transduction approaches and the description of a previously undescribed nanomaterial. Zinc-based nanomaterials offer the opportunity to overcome some of the limitations that are encountered when other nanomaterials are employed for bioassay signal transduction. On the other hand, the biological application of zinc nanomaterials has been difficult because in general their fluorescence is in the blue range and the reported quantum yields are usually too low for highly sensitive applications. The advantages of using zinc nanomaterials for biological applications, such as reduced toxicity, simple synthesis, low cost, and straightforward functionalization strategies contribute to the research interest in their application as

  16. Highly sensitive DNA-based fluorometric mercury(II) bioassay based on graphene oxide and exonuclease III-assisted signal amplification

    International Nuclear Information System (INIS)

    The article describes a fluorometric and sensitive assay for mercury(II) ions (Hg2+). It is based on the following scheme and experimental steps: (1) Hg2+ triggers the self-hybridization of thymine-rich ss-DNA labeled with a fluorescence tag to form a ds-DNA; (2) in the absence of Hg2+, labeled ss-DNA will be adsorbed on the surface of graphene oxide (GO) and its fluorescence is quenched; (3) the ds-DNA formed in the presence of Hg2+ is cleaved by the catalytic action of exonuclease III; (4) the cleaved labeled DNA fragments do not adsorb on the surface of GO, this resulting in an increase in fluorescence intensity. The induction of the process by Hg2+ leads to a strong amplification of fluorescence, while the fluorescence of uncleaved labeled ss-DNA is quenched because it is adsorbed on the surface of GO in the absence of Hg2+. This assay displays a detection limit of 0.1 nM (which is below the 10 nM upper limit in drinking water according to the US EPA and can be performed with 8 min. (author)

  17. Rapid bioassay for oil-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Ashworth, J. [ALS Environmental, Edmonton, AB (Canada); Oosterbroek, L. [HydroQual, Calgary, AB (Canada)

    2010-07-01

    This PowerPoint presentation described a study conducted to develop a rapid bioassay for soils contaminated with oil. The bioassay method was designed for a weight of evidence (WoE) approach and eco-contact guideline derivation protocol. Microtox bioassays were conducted on cyclodextrin extracts of soil quantified by solvent extraction and gas chromatography. The method was demonstrated using straight {beta}-cyclodextrin soil extracts and activated {beta}-cyclodextrin soil extracts. An analysis of the methods showed that the activation step weakens or breaks the cyclodextrin and polycyclic hydrocarbon (PHC) inclusion complex. The released PHC became toxic to the microtox organism. Results from the bioassays were then correlated with earthworm reproduction bioassay results. tabs., figs.

  18. Enhanced spectral sensitivity of a chip-scale photonic-crystal slow-light interferometer

    CERN Document Server

    Magaña-Loaiza, Omar S; Schulz, Sebastian A; Awan, Kashif; Upham, Jeremy; Dolgaleva, Ksenia; Boyd, Robert W

    2016-01-01

    We experimentally demonstrate that the spectral sensitivity of a Mach-Zehnder (MZ) interferometer can be enhanced through structural slow light. We observe a 20 times enhancement by placing a dispersion-engineered-slow-light photonic-crystal waveguide in one arm of a fibre-based MZ interferometer. The spectral sensitivity of the interferometer increases roughly linearly with the group index, and we have quantified the resolution in terms of the spectral density of interference fringes. These results show promise for the use of slow-light methods for developing novel tools for optical metrology and, specifically, for compact high-resolution spectrometers.

  19. Wafer-level chip-scale packaging analog and power semiconductor applications

    CERN Document Server

    Qu, Shichun

    2015-01-01

    This book presents a state-of-art and in-depth overview in analog and power WLCSP design, material characterization, reliability, and modeling. Recent advances in analog and power electronic WLCSP packaging are presented based on the development of analog technology and power device integration. The book covers in detail how advances in semiconductor content, analog and power advanced WLCSP design, assembly, materials, and reliability have co-enabled significant advances in fan-in and fan-out with redistributed layer (RDL) of analog and power device capability during recent years. Along with new analog and power WLCSP development, the role of modeling is a key to assure successful package design. An overview of the analog and power WLCSP modeling and typical thermal, electrical, and stress modeling methodologies is also provided. This book also: ·         Covers the development of wafer-level power discrete packaging with regular wafer-level design concepts and directly bumping technology ·    �...

  20. Coherent population trapping in small- and chip-scale 87Rb vapor cells with buffer gas

    Science.gov (United States)

    Ermak, S. V.; Semenov, V. V.; Petrenko, M. V.; Pyatyshev, E. N.

    2016-03-01

    The characteristics of coherent population trapping (CPT) signal were investigated in small-size glass vapor cells containing 87Rb and Ne buffer gas with narrow line-width laser pumping on D2 line. The parameters of CPT signals were measured using small-size vapor cells with Ne buffer gas pressure in the range of 200-400 Torr, cell temperature in the range of 65-120 ∘C and the values of laser pumping power of 30-400 μW/cm2. Optimal conditions, under which the minimal value of short-term instability of resonance line is achieved, were obtained in experiments. Orientation frequency shifts of CPT resonance using glass 87Rb vapor cells containing buffer gas and anti-relaxation coating were compared. CPT signals using vapor cells based on integrated technologies containing 87Rb in atmosphere of Ne were also investigated. The CPT signals with typical line widths of 2-3 kHz and signal-to-noise ratio of 1500 in 1 Hz bandwidth are observed, which allows one to provide relative frequency instability of 10-11 at 100 s.

  1. Radioistopes to Solar to High Energy Accelerators – Chip-Scale Energy Sources

    International Nuclear Information System (INIS)

    This talk will present MEMS based power sources that utilize radioisotopes, solar energy, and potentially nuclear energy through advancements in integration of new structures and materials within MEMS. Micro power harvesters can harness power from vibration, radioisotopes, light, sound, and biology may provide pathways to minimize or even eliminate batteries in sensor nodes. In this talk work on radioisotope thin films for MEMS will be include the self-reciprocating cantilever, betavoltaic cells, and high DC voltages. The self-reciprocating cantilever energy harvester allows small commercially viable amounts of radioisotopes to generate mW to Watts of power so that very reliable power sources that last 100s of years are possible. The tradeoffs between reliability and potential stigma with radioisotopes allow one to span a useful design space with reliability as a key parameter. These power sources provide pulsed power at three different time scales using mechanical, RF, and static extraction of energy from collected charge. Multi-use capability, both harvesting radioisotope power and local vibration energy extends the reliability of micro-power sources further

  2. A Shrinkage Estimator for Combination of Bioassays

    Institute of Scientific and Technical Information of China (English)

    Jian Xiong; D.G. Chen; Zhen-hai Yang

    2007-01-01

    A shrinkage estimator and a maximum likelihood estimator are proposed in this paper for combination of bioassays. The shrinkage estimator is obtained in closed form which incorporates prior information just on the common log relative potency after the homogeneity test for combination of bioassays is accepted. It is a practical improvement over other estimators which require iterative procedure to obtain the estimator for the relative potency. A real data is also used to show the superiorities for the newly-proposed procedures.

  3. Bioassay criteria for environmental restoration workers

    International Nuclear Information System (INIS)

    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 or 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.)

  4. Bioassays for the determination of nitrification inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Grunditz, Camilla

    1999-07-01

    Requirements for nitrogen reduction in wastewater treatment plants were introduced in Sweden in the early 1990's. This was a governmental move to reduce the nitrogen discharges to the Baltic and Kattegat in order to prevent eutrophication. The nitrification process in wastewater treatment plants is performed by nitrifying bacteria. These are susceptible to inhibition and it is of great importance that the influent water does not contain toxic compounds. Therefore, there is a need for assays for the determination of nitrification inhibition. This thesis describes the development and applications of such bioassays. Pure cultures of Nitrosomonas sp. and Nitrobacter sp. were isolated from activated sludge of a wastewater treatment plant. These cultures were used as test organisms in the development of bioassays for nitrification inhibition measurements. The assays are based on two different principles; cell suspensions of the bacteria, performed in test tubes, and mediated amperometric biosensors with the bacteria immobilised. Ammonia oxidation and nitrite oxidation are studied separately without interference from other organisms, which makes it easier to interpret the results. The cell suspension assays were applied to samples of industrial and municipal wastewater. The Nitrosomonas and Nitrobacter assays showed to have different inhibition patterns. A large percentage of the Swedish municipal wastewater treatment plants were found to receive inhibitory influent water, but the inhibition level was generally low. Compared to an assay based on activated sludge, the screening method, the pure culture assays found more samples of influent water strongly inhibitory or stimulating. The highest correlation was found between the screening method and the Nitrosomonas assay. The Nitrobacter assay was found to be the most sensitive method. Assessment of toxicity of a number of chemical substances was studied using the biosensors, together with the cell suspension assays

  5. Using animal dosimetry models to interpret human bioassay data for actinide exposures

    International Nuclear Information System (INIS)

    Bioassay and dosimetry models are needed to estimate intakes of radionuclides, and to calculate radiation doses to target tissues following such intakes. Because of the diversity of exposure materials, individual biological variabilities, and the general lack of adequate bioassay information and knowledge of the metabolism of radionuclides, current models are based mostly on empiricism. This paper describes biokinetic/dosimetry models for U, Am and Cm. They are based on experimental data developed from studies in dogs that inhaled one of the above radionuclides in specific chemical forms and specific particle sizes. The models, which are based on similar biological principles, and, therefore, have similar structure, are applied to the very sparse human bioassay data available from cases of exposure to either U, Am, or Cm. The results thus far indicate that the lung retention for the different actinides are well described by the models, that urinary bioassay data can be described within limited time periods, and that the fecal excretion rate is not adequately described. Improvements in modeling are predicted on increased publication of human bioassay data, and better cooperative interaction between model developers and health protection professionals responsible for industrial bioassay programs. (author) 36 refs.; 6 figs.; 2 tabs

  6. Soil bioassays and the 129I problem

    International Nuclear Information System (INIS)

    Iodine-129 is a very long-lived radionuclide associated with spent nuclear fuel. Because 129I has a 107-year half-life, is very mobile in the environment and is a biologically essential element, it is the most limiting radionuclide affecting disposal of spent fuel. Traditionally, the potential impacts of 129I have been estimated for human receptors, with the implicit assumption that all other organisms are less at risk. Risk is the operative word, the objective for protection of humans is to protect individuals, whereas the objective for other biota is usually to protect populations. Here, 129I poses an interesting problem: the half-life is so long it is barely radioactive. Thus, the chemical toxicity may be more limiting than the radiological impact. A series of soil bioassays were employed, including a life-cycle plant (Brassica rapa) bioassay, a modified earthworm survival bioassay, a microarthropod colonization/survival bioassay, and a series of more common soil and aquatic bioassays. Chemical toxicity was indicated at soil concentrations as low as 5 mg kg-1. At these levels, radiological impact on non-human biota would not be expected, and therefore the chemical toxicity effects are more critical. However, human food-chain model estimates show these levels, as pure 129I, would be unacceptable for human radiological exposure, so that for 129I, protection of the human environment should also be protective of non-human biota

  7. Plant bioassay to assess the effects of allelochemicals on the metabolome of the target species Aegilops geniculata by an NMR-based approach.

    Science.gov (United States)

    D'Abrosca, Brigida; Scognamiglio, Monica; Fiumano, Vittorio; Esposito, Assunta; Choi, Young Hae; Verpoorte, Robert; Fiorentino, Antonio

    2013-09-01

    A metabolomic-based approach for the study of allelopathic interactions in the Mediterranean area is proposed using Aegilops geniculata Roth (Poaceae), a Mediterranean herbaceous plant, as test species. Its metabolome has been elucidated by 1D and 2D NMR experiments. Hydroponic plant cultures of A. geniculata were treated with specific compounds of known allelopathic potential: catechol, coumarin, p-coumaric acid, p-hydroxybenzoic acid, ferulic acid and juglone. The metabolic variations due to the presence of allelochemicals have been analyzed and measured. All of the compounds showed the strongest effects at the highest concentration, with coumarin and juglone as the most active compounds, causing an increase of several metabolites. The metabolome changes in test plants confirmed the allelochemicals' reported modes of action. The results demonstrated that the proposed method is a promising tool. It can be applied to plant extracts, making it possible to evidence the metabolites responsible for the activity, as well as their mechanisms of action.

  8. Estudo fitoquímico de Unonopsis lindmanii - Annonaceae, biomonitorado pelo ensaio de toxicidade sobre a Artemia salina leach Activity - guided isolation of constituents of Unonopsis lindmanii - Annonaceae, based on the brine shrimp lethality bioassay

    Directory of Open Access Journals (Sweden)

    João Máximo de Siqueira

    1998-10-01

    Full Text Available Extracts obtained from leaves, seeds and bark of Unonopsis lindmanii were evaluated by means of Brine Shrimp Lethality test (BSL. Through bioassay-guided chromatographic fractionation, liriodenine, an oxoaporphine alkaloid, was isolated from the bark extracts as the bioactive compound. Two additional inactive known alkaloids, unonopsine and lysicamine were also isolated from the bark extracts.

  9. Brine Shrimp Bioassays: A Useful Technique in Biological Investigations

    Science.gov (United States)

    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.

  10. The extended Beer-Lambert theory for ray tracing modeling of LED chip-scaled packaging application with multiple luminescence materials

    Science.gov (United States)

    Yuan, Cadmus C. A.

    2015-12-01

    Optical ray tracing modeling applied Beer-Lambert method in the single luminescence material system to model the white light pattern from blue LED light source. This paper extends such algorithm to a mixed multiple luminescence material system by introducing the equivalent excitation and emission spectrum of individual luminescence materials. The quantum efficiency numbers of individual material and self-absorption of the multiple luminescence material system are considered as well. By this combination, researchers are able to model the luminescence characteristics of LED chip-scaled packaging (CSP), which provides simple process steps and the freedom of the luminescence material geometrical dimension. The method will be first validated by the experimental results. Afterward, a further parametric investigation has been then conducted.

  11. Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays.

    Science.gov (United States)

    Jahnke, Annika; Mayer, Philipp; Schäfer, Sabine; Witt, Gesine; Haase, Nora; Escher, Beate I

    2016-06-01

    Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing. PMID:26804122

  12. Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays

    DEFF Research Database (Denmark)

    Jahnke, Annika; Mayer, Philipp; Schäfer, Sabine;

    2016-01-01

    Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment...... and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the...... environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total...

  13. Pooling techniques for bioassay screening

    International Nuclear Information System (INIS)

    Pooling techniques commonly are used to increase the throughput of samples used for screening purposes. While advantages of such techniques are increased analytical efficiency and cost savings, the sensitivity of measurements decreases because it is inversely proportional to the number of samples m the pools. Consequently, uncertainties in estimates of dose and risk which are based on the results of pooled samples increase as the number of samples in the pools increases m all applications. However, sensitivities may not be seriously degraded, for example, in urinanalysis, if the samples in the pools are of known time duration, or if the fraction of some attribute of the grab urine samples to that m a 24-hour composite is known (e.g., mass, specific gravity, creatinine, or volume, per 24-h interval). This paper presents square and cube pooling schemes that greatly increase throughput and can considerably reduce analytical costs (on a sample basis). The benefit-cost ratios for 5x5 square and 5x5x5 cube pooling schemes are 2.5 and 8.3, respectively. Three-dimensional and higher arrayed pooling schemes would result in even greater economies; however, significant improvements in analytical sensitivity are required to achieve these advantages. These are various other considerations for designing a pooling scheme, where the number of dimensions and of samples in the optimum array are influenced by: 1) the minimal detectable amount (MDA) of the analytical processes, 2) the screening dose-rate requirements, 3) the maximum masses or volumes of the composite samples that can be analyzed, 4) the information already available from results of composite analysis, and 5) the ability of an analytical system to guard against both false negative and false positive results. Many of these are beyond the scope of this paper but are being evaluated. (author)

  14. Investigating the resistance of wild oat (Avena ludoviciana Durieu.) to fenoxaprop-p-ethyl by whole plant bioassay and seed bioassay.

    Science.gov (United States)

    Kashani, Fatemeh Bena; Alizadeh, Hasan Mohammad; Zand, Eskandar

    2007-01-01

    Greenhouse and laboratory experiments were performed to evaluate the resistant of wild oat Avena luduviciana Durieu. populations to fenoxaprop-p-ethyl. Populations of A. ludoviciana were collected from different locations in Iran, showed indications of resistance to this herbicide. Whole plant assay experiments included screening tests and dose response experiments whereas; seed bioassay experiment consisted of ID50 determination and dose response experiments. Whole plant assay experiments were conducted as a randomized complete block design in four replications. The treatments were wild oat populations included FR1, FR2, FR3, FR4 (collected from Fars province), MR1, MR2, MR3 (collected from Markazi province), KS, KR1, KR2, KR3 (collected from Khuzestan province) and S (collected from location which had never been treated previously with any graminicide). Seed bioassay experiments were conducted using a randomized design with 4 replications. On the whole plant basis, resistance was found in, KR1, KR2, KR3 and FR4 and based on a seed bioassay, these populations were also resistant to fenoxaprop-p-ethyl. Resistance ratios (R/S) of resistant populations were different. Present findings also revealed that the seed bioassay could be used as a simple, comparatively rapid, inexpensive and accurate method for identifying wild oat populations resistant to Acetyl CoA carboxylase (ACCase) inhibitors.

  15. Development and application of bioassays for a site-specific risk assessment of contaminated soil

    OpenAIRE

    Rila, J.-P.

    2008-01-01

    Soil risk assessment based on generic approaches is accompanied by a large number of uncertainties. In site-specific risk assessment aimed at identifying the actual effects on the ecosystem by using e.g. bioassays in soil elutriates and taking into account land-use these uncertainties can be largely reduced. In this thesis the application and development of bioassays for a site-specific risk assessment of contaminated soil has been discussed. The first part of this thesis deals with the influ...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  18. In-situ bioassays using caged bivalves

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, M.H.; Salazar, S.M.

    1995-12-31

    It is important to make the distinction between chemical measurements to assess bioaccumulation potential versus biological measurements to assess potential bioeffects because bioaccumulation is not a bioeffect. Caging provides a unique opportunity to make synoptic measurements of each and facilitates making these measurements over space and time. Measuring bioaccumulation in resident and transplanted bivalves has probably been the most frequently used form of an in-situ bioassay because bivalves concentrate chemicals in their tissues. They are also easy to collect, cage, and measure. The authors have refined bivalve bioassay methods by minimizing the size range of test animals, making repetitive measurements of the same individuals, and standardizing 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. Growth measurements can serve two purposes in this assessment strategy: (1) An integrated biological response endpoint that is easily quantifiable and with significance to the population, and (2) A means of calibrating bioaccumulation by assessing the relative health and physiological state of tissues that have accumulated the chemicals. In general, the authors have found the highest bioconcentration factors associated with the highest growth rates, the highest concentrations ({micro}g/g) of chemicals in juvenile mussels, and the highest chemical content ({micro}g/animal) in adult mussels. Without accounting for possible dilution of chemical concentrations by tissue growth or magnification through degrowth, contaminant concentrations can be misleading. Examples are provided for the Sudbury River in Massachusetts (Elliptio complanata), San Diego Bay (Mytilus galloprovincialis), and the Harbor Island Superfund Site in Puget Sound (Mytilus trossulus).

  19. A Multichannel Bioluminescence Determination Platform for Bioassays.

    Science.gov (United States)

    Kim, Sung-Bae; Naganawa, Ryuichi

    2016-01-01

    The present protocol introduces a multichannel bioluminescence determination platform allowing a high sample throughput determination of weak bioluminescence with reduced standard deviations. The platform is designed to carry a multichannel conveyer, an optical filter, and a mirror cap. The platform enables us to near-simultaneously determine ligands in multiple samples without the replacement of the sample tubes. Furthermore, the optical filters beneath the multichannel conveyer are designed to easily discriminate colors during assays. This optical system provides excellent time- and labor-efficiency to users during bioassays.

  20. Aspartame bioassay findings portend human cancer hazards.

    Science.gov (United States)

    Huff, James; LaDou, Joseph

    2007-01-01

    The U.S. Food and Drug Administration (FDA) should reevaluate its position on aspartame as being safe under all conditions. Animal bioassay results predict human cancer risks, and a recent animal study confirms that there is a potential aspartame risk to humans. Aspartame is produced and packaged in China for domestic use and global distribution. Japan, France, and the United States are also major producers. No study of long-term adverse occupational health effects on aspartame workers have been conducted. The FDA should consider sponsoring a prospective epidemiologic study of aspartame workers.

  1. A Multichannel Bioluminescence Determination Platform for Bioassays.

    Science.gov (United States)

    Kim, Sung-Bae; Naganawa, Ryuichi

    2016-01-01

    The present protocol introduces a multichannel bioluminescence determination platform allowing a high sample throughput determination of weak bioluminescence with reduced standard deviations. The platform is designed to carry a multichannel conveyer, an optical filter, and a mirror cap. The platform enables us to near-simultaneously determine ligands in multiple samples without the replacement of the sample tubes. Furthermore, the optical filters beneath the multichannel conveyer are designed to easily discriminate colors during assays. This optical system provides excellent time- and labor-efficiency to users during bioassays. PMID:27424912

  2. Evidence of Resistance to Cry34/35Ab1 Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae): Root Injury in the Field and Larval Survival in Plant-Based Bioassays.

    Science.gov (United States)

    Gassmann, Aaron J; Shrestha, Ram B; Jakka, Siva R K; Dunbar, Mike W; Clifton, Eric H; Paolino, Aubrey R; Ingber, David A; French, B Wade; Masloski, Kenneth E; Dounda, John W; St Clair, Coy R

    2016-08-01

    Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a serious pest of corn in the United States, and recent management of western corn rootworm has included planting of Bt corn. Beginning in 2009, western corn rootworm populations with resistance to Cry3Bb1 corn and mCry3A corn were found in Iowa and elsewhere. To date, western corn rootworm populations have remained susceptible to corn producing Bt toxin Cry34/35Ab1. In this study, we used single-plant bioassays to test field populations of western corn rootworm for resistance to Cry34/35Ab1 corn, Cry3Bb1 corn, and mCry3A corn. Bioassays included nine rootworm populations collected from fields where severe injury to Bt corn had been observed and six control populations that had never been exposed to Bt corn. We found incomplete resistance to Cry34/35Ab1 corn among field populations collected from fields where severe injury to corn producing Cry34/35Ab1, either singly or as a pyramid, had been observed. Additionally, resistance to Cry3Bb1 corn and mCry3A corn was found among the majority of populations tested. These first cases of resistance to Cry34/35Ab1 corn, and the presence of resistance to multiple Bt toxins by western corn rootworm, highlight the potential vulnerability of Bt corn to the evolution of resistance by western corn rootworm. The use of more diversified management practices, in addition to insect resistance management, likely will be essential to sustain the viability of Bt corn for management of western corn rootworm. PMID:27329619

  3. Toxicity assessment using different bioassays and microbial biosensors.

    Science.gov (United States)

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

    2016-01-01

    Toxicity assessment of water streams, wastewater, and contaminated sediments, is a very important part of environmental pollution monitoring. Evaluation of biological effects using a rapid, sensitive and cost effective method can indicate specific information on ecotoxicity assessment. Recently, different biological assays for toxicity assessment based on higher and lower organisms such as fish, invertebrates, plants and algal cells, and microbial bioassays have been used. This review focuses on microbial biosensors as an analytical device for environmental, food, and biomedical applications. Different techniques which are commonly used in microbial biosensing include amperometry, potentiometry, conductometry, voltammetry, microbial fuel cells, fluorescence, bioluminescence, and colorimetry. Examples of the use of different microbial biosensors in assessing a variety of environments are summarized. PMID:27071051

  4. Benthic invertebrate bioassays with toxic sediment and pore water

    Science.gov (United States)

    Giesy, John P.; Rosiu, Cornell J.; Graney, Robert L.; Henry, Mary G.

    1990-01-01

    The relative sensitivities of bioassays to determine the toxicity of sediments were investigated and three methods of making the sample dilutions required to generate dose-response relationships were compared. The assays studied were: (a) Microtox®, a 15-min assay ofPhotobacterium phosphoreum bioluminescence inhibition by pore water; (b) 48-h Daphnia magnalethality test in pore water; (c) 10-d subchronic assay of lethality to and reduction of weight gain by Chironomus tentans performed in either whole sediment or pore water; (d) 168-h acute lethality assay of Hexagenia limbata in either whole sediment or pore water. The three methods of diluting sediments were: (a) extracting pore water from the toxic location and dilution with pore water from the control station; (b) diluting whole sediment from the toxic location with control whole sediment from a reference location, then extracting pore water; and (c) diluting toxic, whole sediment with whole sediment from a reference location, then using the whole sediment in bioassays. Based on lethality, H. limbata was the most sensitive organism to the toxicity of Detroit River sediment. Lethality of D. magna in pore water was similar to that of H. limbata in whole sediment and can be used to predict effects of whole sediment toxicity to H. limbata. The concentration required to cause a 50% reduction in C. tentans growth (10-d EC50) was approximately that which caused 50% lethality of D. magna (48-h LC50) and was similar to the toxicity that restricts benthic invertebrate colonization of contaminated sediments. While the three dilution techniques gave similar results with some assays, they gave very different results in other assays. The dose-response relationships determined by the three dilution techniques would be expected to vary with sediment, toxicant and bioassay type, and the dose-response relationship derived from each technique needs to be interpreted accordingly.

  5. Comparison of two bioassay methods for determining deltamethrin resistance in German cockroaches (Blattodea: Blattellidae).

    Science.gov (United States)

    Choo, L E; Tang, C S; Pang, F Y; Ho, S H

    2000-06-01

    Susceptibility to deltamethrin of 10 strains of the German cockroach, Blattella germanica (L.), trapped in hotel kitchens in Singapore was determined. Two resistance detection bioassay methods (topical application and World Health Organization glass jar method) were compared. Resistance ratios based on 50% knockdown, obtained by comparison with the S strain, ranged from 17.7 to 4,235 for topical application and from 2.2 to 22 for the glass jar method. A field strain, with consistently low resistance ratios (topical method = 17.7, glass jar method = 2.2), was identified as a potential field strain to be used as a baseline for comparison with other field strains. Resistance ratios for the other field strains obtained by comparison with the R5 strain ranged from 24.5 to 239 for topical application and from 1.2 to 9.8 for the glass jar method. The results of our study demonstrate that deltamethrin-resistant German cockroaches are numerous in Singapore. Comparison between the two bioassay methods showed that there was significant correlation between KD50 and KT50 values. The glass jar method is similar to field situations but topical application is sensitive enough to define the magnitude of resistance. Differences between the two detection bioassays and the factors governing the choice of bioassay in monitoring resistance in German cockroaches are discussed. PMID:10902348

  6. Microstructural Evolution of SAC305 Solder Joints in Wafer Level Chip-Scale Packaging (WLCSP) with Continuous and Interrupted Accelerated Thermal Cycling

    Science.gov (United States)

    Zhou, Quan; Zhou, Bite; Lee, Tae-Kyu; Bieler, Thomas

    2016-06-01

    Four high-strain design wafer level chip scale packages were given accelerated thermal cycling with a 10°C/min ramp rate and 10 min hold times between 0°C and 100°C to examine the effects of continuous and interrupted thermal cycling on the number of cycles to failure. The interruptions given two of the samples were the result of periodic examinations using electron backscattered pattern mapping, leading to room temperature aging of 30 days-2.5 years after increments of about 100 cycles at several stages of the cycling history. The continuous thermal cycling resulted in solder joints with a much larger degree of recrystallization, whereas the interrupted thermal cycling tests led to much less recrystallization, which was more localized near the package side, and the crack was more localized near the interface and had less branching. The failure mode for both conditions was still the same, with cracks nucleating along the high angle grain boundaries formed during recrystallization. In conditions where there were few recrystallized grains, recovery led to formation of subgrains that strengthened the solder, and the higher strength led to a larger driving force for crack growth through the solder, leading to failure after less than half of the cycles in the continuous accelerated thermal cycling condition. This work shows that there is a critical point where sufficient strain energy accumulation will trigger recrystallization, but this point depends on the rate of strain accumulation in each cycle and various recovery processes, which further depends on local crystal orientations, stress state evolution, and specific activated slip and twinning systems.

  7. Comprehensive integration of homogeneous bioassays via centrifugo-pneumatic cascading.

    Science.gov (United States)

    Godino, Neus; Gorkin, Robert; Linares, Ana V; Burger, Robert; Ducrée, Jens

    2013-02-21

    This work for the first time presents the full integration and automation concept for a range of bioassays leveraged by cascading a centrifugo-pneumatic valving scheme to sequentially move several liquids through shared channel segments for multi-step sample preparation into the detection zone. This novel centrifugo-pneumatic liquid handling significantly simplifies system manufacture by obviating the need for complex surface functionalization procedures or hybrid material integration, as it is common in conventional valving methods such as capillary burst valves or sacrificial valves. Based on the centrifugo-pneumatic valving scheme, this work presents a toolkit of operational elements implementing liquid loading/transfer, metering, mixing and sedimentation in a microstructured polymer disc. As a proof of concept for the broad class of homogeneous bioassays, the full integration and automation of a colorimetric nitrate/nitrite test for the detection of clinically relevant nitric oxide (NO) in whole blood is implemented. First, 40 μL of plasma is extracted from a 100 μL sample of human blood, incubated for one hour with the enzymatic mixture (60 μL), and finally reacted with 100 μL of colorimetric (Greiss) reagents. Following just a single loading phase at the beginning of the process, all of these steps are automated through the centrifugo-pneumatic cascade with a high level of flow control and synchronization. Our system shows good correlation with controls up to 50 μM of nitrate, which adequately covers the healthy human range (4 to 45.3 μM). PMID:23250328

  8. A novel bioassay using root re-growth in Lemna.

    Science.gov (United States)

    Park, Areum; Kim, Youn-Jung; Choi, Eun-Mi; Brown, Murray T; Han, Taejun

    2013-09-15

    A new phytotoxicity test method based on root elongation of three Lemna species (Lemna gibba, L. minor, and L. paucicostata) has been developed. Tests with aquatic plants have, typically, favored measurements on fronds (e.g. frond number, area, biomass) rather than on roots, due, in part, to issues associated with handling fragile roots and the time-consuming procedures of selecting roots with identical root lengths. The present method differs in that roots were excised prior to exposure with subsequent measurements on newly developed roots. Results show that there were species-specific difference in sensitivity to the five metals tested (Ag, Cd, Cr, Cu and Hg), with Ag being the most toxic (EC50=5.3-37.6 μgL(-1)) to all three species, and Cr the least toxic for L. gibba and L. minor (1148.3 and 341.8 μgL(-1), respectively) and Cu for L. paucicostata (470.4 μgL(-1)). Direct comparisons were made with measurements of frond area, which were found to be less sensitive. More generally, root re-growth was shown to reflect the toxic responses of all three Lemna species to these five important metals. The root growth bioassay differs from three internationally standardized methods (ISO, OCED and US EPA) in that it is completed in 48 h, the required volume of test solutions is only 3 ml and non-axenic plants are used. Our results show that the Lemna root method is a simple, rapid, cost-effective, sensitive and precise bioassay to assess the toxic risks of metals and has practical application for monitoring municipal and industrial waste waters where metals are common constituents. PMID:23917640

  9. A statistical treatment of bioassay pour fractions

    Science.gov (United States)

    Barengoltz, Jack; Hughes, David

    A bioassay is a method for estimating the number of bacterial spores on a spacecraft surface for the purpose of demonstrating compliance with planetary protection (PP) requirements (Ref. 1). The details of the process may be seen in the appropriate PP document (e.g., for NASA, Ref. 2). In general, the surface is mechanically sampled with a damp sterile swab or wipe. The completion of the process is colony formation in a growth medium in a plate (Petri dish); the colonies are counted. Consider a set of samples from randomly selected, known areas of one spacecraft surface, for simplicity. One may calculate the mean and standard deviation of the bioburden density, which is the ratio of counts to area sampled. The standard deviation represents an estimate of the variation from place to place of the true bioburden density commingled with the precision of the individual sample counts. The accuracy of individual sample results depends on the equipment used, the collection method, and the culturing method. One aspect that greatly influences the result is the pour fraction, which is the quantity of fluid added to the plates divided by the total fluid used in extracting spores from the sampling equipment. In an analysis of a single sample’s counts due to the pour fraction, one seeks to answer the question: What is the probability that if a certain number of spores are counted with a known pour fraction, that there are an additional number of spores in the part of the rinse not poured. This is given for specific values by the binomial distribution density, where detection (of culturable spores) is success and the probability of success is the pour fraction. A special summation over the binomial distribution, equivalent to adding for all possible values of the true total number of spores, is performed. This distribution when normalized will almost yield the desired quantity. It is the probability that the additional number of spores does not exceed a certain value. Of course

  10. Information for establishing bioassay measurements and evaluations of tritium exposure

    International Nuclear Information System (INIS)

    This report summarizes information and references used in developing regulatory guidance on programs for the bioassay of tritium as well as information useful in planning and conducting tritium bioassay programs and evaluating bioassay data. A review of literature on tritium radiobiology is included to provide a ready source of information useful for estimating internal doses of tritium and risks for the various tritium compounds and forms, including elemental (gaseous) tritium. Simplified and conservative dose conversion factors are derived and tabulated for easy reference in program planning, safety evaluations, and compliance determinations

  11. Collection and control of tritium bioassay samples at Pantex

    International Nuclear Information System (INIS)

    Pantex is the final assembly/disassembly point for US nuclear weapons. The Pantex internal dosimetry section monitors radiation workers once a month for tritium exposure. In order to manage collection and control of the bioassay specimens efficiently, a bar code system for collection of samples was developed and implemented to speed up the process and decrease the number of errors probable when transferring data. In the past, all the bioassay data from samples were entered manually into a computer database. Transferring the bioassay data from the liquid scintillation counter to each individual's dosimetry record required as much as two weeks of concentrated effort

  12. The OECD program to validate the rat Hershberger bioassay to screen compounds for in vivo and androgen and antiandrogen responses: Phase-2 dose-response studies

    Science.gov (United States)

    DESIGN: The Hershberger bioassay is designed to identify suspected androgens and antiandrogens based on changes in the weights of five androgen-responsive tissues (ventral prostate, paired seminal vesicles and coagulating glands, the levator ani and bulbocavernosus muscles, the g...

  13. Bioassay-Directed Fractionation of Diesel and Biodiesel Emissions

    Science.gov (United States)

    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...

  14. Plant bioassays to assess toxicity of textile sludge compost

    OpenAIRE

    Araújo Ademir Sérgio Ferreira de; Monteiro Regina Teresa Rosim

    2005-01-01

    Composting of industrial wastes is increasing because of recycling requirements set on organic wastes. The evaluation of toxicity of these wastes by biological testing is therefore extremely important for screening the suitability of waste for land application. The toxicity of a textile sludge compost was investigated using seed germination and plant growth bioassays using soybean and wheat. Compost samples were mixed with water (seed germination bioassay) or nutrient solution (plant growth b...

  15. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays.

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Mitchell R.; Fruetel, Julia A.; Foster, Michael E.; Hayden, Carl C.; Buckley, Heather L.; Arnold, John

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26590191

  18. Soil bioassays and the {sup 129}I problem

    Energy Technology Data Exchange (ETDEWEB)

    Sheppard, S.C. [Atomic Energy of Canada Ltd., Pinawa, Manitoba (Canada)

    1995-12-31

    Iodine-129 is a very long-lived radionuclide associated with spent nuclear fuel. Because {sup 129}I has a 10{sup 7}-year half-life, is very mobile in the environment and is a biologically essential element, it is the most limiting radionuclide affecting disposal of spent fuel. Traditionally, the potential impacts of {sup 129}I have been estimated for human receptors, with the implicit assumption that all other organisms are less at risk. Risk is the operative word, the objective for protection of humans is to protect individuals, whereas the objective for other biota is usually to protect populations. Here, {sup 129}I poses an interesting problem: the half-life is so long it is barely radioactive. Thus, the chemical toxicity may be more limiting than the radiological impact. A series of soil bioassays were employed, including a life-cycle plant (Brassica rapa) bioassay, a modified earthworm survival bioassay, a microarthropod colonization/survival bioassay, and a series of more common soil and aquatic bioassays. Chemical toxicity was indicated at soil concentrations as low as 5 mg kg{sup {minus}1}. At these levels, radiological impact on non-human biota would not be expected, and therefore the chemical toxicity effects are more critical. However, human food-chain model estimates show these levels, as pure {sup 129}I, would be unacceptable for human radiological exposure, so that for {sup 129}I, protection of the human environment should also be protective of non-human biota.

  19. Translating bioassay results to field population responses using a Leslie-matrix model for the marine amphipod Corophium volutator

    NARCIS (Netherlands)

    Smit, M.G.D.; Kater, B.J.; Jak, R.G.; Heuvel-Greve, van den M.J.

    2006-01-01

    Bioassays can be used for the assessment of sediment contamination. The response is classified based on a statistical scale indicating a certain effect percentage being significantly different from the controls (e.g. mortality classes of 0¿10%, 10¿20% etc.). The ecological relevance of this statisti

  20. In Vitro Androgen Bioassays as a Detection Method for Designer Androgens

    Directory of Open Access Journals (Sweden)

    Alison K. Heather

    2013-02-01

    Full Text Available 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.

  1. The effect of pesticide residue on caged mosquito bioassays.

    Science.gov (United States)

    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. PMID:17067048

  2. Bioassay for investigation of auxin transport in single cell layers

    Directory of Open Access Journals (Sweden)

    Alina B. Wodzicki

    2014-02-01

    Full Text Available Auxin was collected from the cambial region of Pinus sylvestris by applying agar strips to the cut surfaces of stem sections which comprised a single layer of 2 to 4-mm long, mainly intact fusiform cells. Sections of the agar strips were either bioassayed immediately to determine their auxin content or stored for several months at -80oC, extracted with 80% MeOH and redissolved in hot agar prior to bioassay. Auxin concentrations were determined by Went's oat coleoptile test, as described by Funke, which was modified considerably to give highly reproducible results. The modifications proved essential for good replication of results and are described in detail together with the use of the bioassay to determine changes in cambial cell polarity during ageing and senescence in P. sylvestris.

  3. An emergency bioassay method for actinides in urine.

    Science.gov (United States)

    Dai, Xiongxin; Kramer-Tremblay, Sheila

    2011-08-01

    A rapid bioassay method has been developed for the sequential measurements of actinides in human urine samples. The method involves actinide separation from a urine matrix by co-precipitation with hydrous titanium oxide (HTiO), followed by anion exchange and extraction chromatography column purification, and final counting by alpha spectrometry after cerium fluoride micro-precipitation. The minimal detectable activities for the method were determined to be 20 mBq L(-1) or less for plutonium, uranium, americium and curium isotopes, with an 8-h sample turn-around time. Spike tests showed that this method would meet the requirements for actinide bioassay following a radiation emergency. PMID:21709501

  4. An examination of the analysis of radiostrontiums in bioassay applications

    International Nuclear Information System (INIS)

    Radiostrontiums are among the most radiologically significant radionuclides in the nuclear reactor environment due to their relatively high fission yield, long physical half-life, volatility and mobility in the workplace, and long retention times in tissues such as bone. Effective bioassay programs include analytical processes that consider prospective monitoring requirements provided by screening measurements, as well as the retrospective monitoring requirements provided by screening measurements following an intake. Chromatography using crown ethers as well as the use of spectrometry techniques with advanced liquid-scintillation counters or solid-state surface-barrier detectors appear to have significant benefits for Sr bioassay programs. (author). 90 refs., 2 tabs., 3 figs

  5. Cleavable DNA-protein hybrid molecular beacon: A novel efficient signal translator for sensitive fluorescence anisotropy bioassay.

    Science.gov (United States)

    Hu, Pan; Yang, Bin

    2016-01-15

    Due to its unique features such as high sensitivity, homogeneous format, and independence on fluorescent intensity, fluorescence anisotropy (FA) assay has become a hotspot of study in oligonucleotide-based bioassays. However, until now most FA probes require carefully customized structure designs, and thus are neither generalizable for different sensing systems nor effective to obtain sufficient signal response. To address this issue, a cleavable DNA-protein hybrid molecular beacon was successfully engineered for signal amplified FA bioassay, via combining the unique stable structure of molecular beacon and the large molecular mass of streptavidin. Compared with single DNA strand probe or conventional molecular beacon, the DNA-protein hybrid molecular beacon exhibited a much higher FA value, which was potential to obtain high signal-background ratio in sensing process. As proof-of-principle, this novel DNA-protein hybrid molecular beacon was further applied for FA bioassay using DNAzyme-Pb(2+) as a model sensing system. This FA assay approach could selectively detect as low as 0.5nM Pb(2+) in buffer solution, and also be successful for real samples analysis with good recovery values. Compatible with most of oligonucleotide probes' designs and enzyme-based signal amplification strategies, the molecular beacon can serve as a novel signal translator to expand the application prospect of FA technology in various bioassays.

  6. Enhancing the response of CALUX and CAFLUX cell bioassays for quantitative detection of dioxin-like compounds

    Institute of Scientific and Technical Information of China (English)

    BASTON; David; S.; KHAN; Elaine; SORRENTINO; Claudio; DENISON; Michael; S.

    2010-01-01

    Reporter genes produce a protein product in transfected cells that can be easily measured in intact or lysed cells and they have been extensively used in numerous basic and applied research applications.Over the past 10 years,reporter gene assays have been widely accepted and used for analysis of 2,3,7,8-tetrachlorodibenzo-p-dioxin and related dioxin-like compounds in various types of matrices,such as biological,environmental,food and feed samples,given that high-resolution instrumental analysis techniques are impractical for large-scale screening analysis.The most sensitive cell-based reporter gene bioassay systems developed are the mechanism-based CALUX(Chemically Activated Luciferase Expression) and CAFLUX(Chemically Activated Fluorescent Expression) bioassays,which utilize recombinant cell lines containing stably transfected dioxin(AhR) responsive firefly luciferase or enhanced green fluorescent protein(EGFP) reporter genes,respectively.While the current CALUX and CAFLUX bioassays are very sensitive,increasing their lower limit of sensitivity,magnitude of response and dynamic range for chemical detection would significantly increase their utility,particularly for those samples that contain low levels of dioxin-like HAHs(i.e.,serum) .In this study,we report that the addition of modulators of cell signaling pathways or modification of cell culture conditions results in significant improvement in the magnitude and overall responsiveness of the existing CALUX and CAFLUX cell bioassays.

  7. Cleavable DNA-protein hybrid molecular beacon: A novel efficient signal translator for sensitive fluorescence anisotropy bioassay.

    Science.gov (United States)

    Hu, Pan; Yang, Bin

    2016-01-15

    Due to its unique features such as high sensitivity, homogeneous format, and independence on fluorescent intensity, fluorescence anisotropy (FA) assay has become a hotspot of study in oligonucleotide-based bioassays. However, until now most FA probes require carefully customized structure designs, and thus are neither generalizable for different sensing systems nor effective to obtain sufficient signal response. To address this issue, a cleavable DNA-protein hybrid molecular beacon was successfully engineered for signal amplified FA bioassay, via combining the unique stable structure of molecular beacon and the large molecular mass of streptavidin. Compared with single DNA strand probe or conventional molecular beacon, the DNA-protein hybrid molecular beacon exhibited a much higher FA value, which was potential to obtain high signal-background ratio in sensing process. As proof-of-principle, this novel DNA-protein hybrid molecular beacon was further applied for FA bioassay using DNAzyme-Pb(2+) as a model sensing system. This FA assay approach could selectively detect as low as 0.5nM Pb(2+) in buffer solution, and also be successful for real samples analysis with good recovery values. Compatible with most of oligonucleotide probes' designs and enzyme-based signal amplification strategies, the molecular beacon can serve as a novel signal translator to expand the application prospect of FA technology in various bioassays. PMID:26592607

  8. 'In-vivo' and bioassay results from two contrasting cases of plutonium-239 inhalation

    International Nuclear Information System (INIS)

    'In-vivo' and bioassay measurements following two incidents involving plutonium-239 inhalation are described and contrasted. Incident 1, involving the inhalation of insoluble plutonium oxide, resulted in a lung content of about 20 nCi after the initial clearance. Urine excretion was negligible and the estimation of exposure was based on 'in-vivo' data and faecal excretion. Incident,2, involving the inhalation of soluble plutonium, proved negligible and the estimation of exposure, based on urinary excretion, was 0.6 nCi. (author)

  9. Bioassays for evaluation of medical products derived from bacterial toxins.

    Science.gov (United States)

    Sesardic, Thea

    2012-06-01

    Bioassays play central role in evaluation of biological products and those derived from bacterial toxins often rely exclusively on in vivo models for assurance of safety and potency. This chapter reviews existing regulatory approved methods designed to provide information on potency and safety of complex biological medicines with an insight into strategies considered for alternative procedures.

  10. Assessment of acrylamide toxicity using a battery of standardised bioassays.

    Science.gov (United States)

    Zovko, Mira; Vidaković-Cifrek, Željka; Cvetković, Želimira; Bošnir, Jasna; Šikić, Sandra

    2015-12-01

    Acrylamide is a monomer widely used as an intermediate in the production of organic chemicals, e.g. polyacrylamides (PAMs). Since PAMs are low cost chemicals with applications in various industries and waste- and drinking water treatment, a certain amount of non-polymerised acrylamide is expected to end up in waterways. PAMs are non-toxic but acrylamide induces neurotoxic effects in humans and genotoxic, reproductive, and carcinogenic effects in laboratory animals. In order to evaluate the effect of acrylamide on freshwater organisms, bioassays were conducted on four species: algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata, duckweed Lemna minor and water flea Daphnia magna according to ISO (International Organization for Standardisation) standardised methods. This approach ensures the evaluation of acrylamide toxicity on organisms with different levels of organisation and the comparability of results, and it examines the value of using a battery of low-cost standardised bioassays in the monitoring of pollution and contamination of aquatic ecosystems. These results showed that EC50 values were lower for Desmodesmus subspicatus and Pseudokirchneriella subcapitata than for Daphnia magna and Lemna minor, which suggests an increased sensitivity of algae to acrylamide. According to the toxic unit approach, the values estimated by the Lemna minor and Daphnia magna bioassays, classify acrylamide as slightly toxic (TU=0-1; Class 1). The results obtained from algal bioassays (Desmodesmus subspicatus and Pseudokirchneriella subcapitata) revealed the toxic effect of acrylamide (TU=1-10; Class 2) on these organisms.

  11. STRESS ETHYLENE: A BIOASSAY FOR RHIZOSPHERE-APPLIED PHYTOTOXICANTS

    Science.gov (United States)

    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 ...

  12. Field deployable technique for 90Sr emergency bioassay

    International Nuclear Information System (INIS)

    Rapid bioassay is very important for immediate and near-term consequence management, which includes identifying contaminated individuals and providing necessary medical intervention during a radiological or nuclear emergency. This paper reports the application of a newly developed bioassay technique for 90Sr in urine on a field deployable instrument, the TriathlerR. Performance of this field technique for sensitivity, accuracy and repeatability is evaluated against bioassay criteria (ANSI N13.30). This field technique offers the following analytical merits: (1) minimum detectable activity of 121 Bq l-1 when 20 ml of urine is used; (2) relative bias of 11.1% and relative precision of 3.2% at the level of 45 Bq per 20 ml of urine and (3) sample turnaround time of less than 1 h. The technique meets the requirements for emergency bioassay when a committed effective dose of 0.5 Sv is used as the action dose threshold for medical intervention. Sample throughput can be significantly improved if this technique is automated. (authors)

  13. Microplate Bioassay for Determining Substrate Selectivity of "Candida rugosa" Lipase

    Science.gov (United States)

    Wang, Shi-zhen; Fang, Bai-shan

    2012-01-01

    Substrate selectivity of "Candida rugosa" lipase was tested using "p"-nitrophenyl esters of increasing chain length (C[subscript 1], C[subscript 7], C[subscript 15]) using the high-throughput screening method. A fast and easy 96-well microplate bioassay was developed to help students learn and practice biotechnological specificity screen. The…

  14. Assessment of acrylamide toxicity using a battery of standardised bioassays.

    Science.gov (United States)

    Zovko, Mira; Vidaković-Cifrek, Željka; Cvetković, Želimira; Bošnir, Jasna; Šikić, Sandra

    2015-12-01

    Acrylamide is a monomer widely used as an intermediate in the production of organic chemicals, e.g. polyacrylamides (PAMs). Since PAMs are low cost chemicals with applications in various industries and waste- and drinking water treatment, a certain amount of non-polymerised acrylamide is expected to end up in waterways. PAMs are non-toxic but acrylamide induces neurotoxic effects in humans and genotoxic, reproductive, and carcinogenic effects in laboratory animals. In order to evaluate the effect of acrylamide on freshwater organisms, bioassays were conducted on four species: algae Desmodesmus subspicatus and Pseudokirchneriella subcapitata, duckweed Lemna minor and water flea Daphnia magna according to ISO (International Organization for Standardisation) standardised methods. This approach ensures the evaluation of acrylamide toxicity on organisms with different levels of organisation and the comparability of results, and it examines the value of using a battery of low-cost standardised bioassays in the monitoring of pollution and contamination of aquatic ecosystems. These results showed that EC50 values were lower for Desmodesmus subspicatus and Pseudokirchneriella subcapitata than for Daphnia magna and Lemna minor, which suggests an increased sensitivity of algae to acrylamide. According to the toxic unit approach, the values estimated by the Lemna minor and Daphnia magna bioassays, classify acrylamide as slightly toxic (TU=0-1; Class 1). The results obtained from algal bioassays (Desmodesmus subspicatus and Pseudokirchneriella subcapitata) revealed the toxic effect of acrylamide (TU=1-10; Class 2) on these organisms. PMID:26751864

  15. Bioassay for aquatic ecosystems review and classification; Rassegna dei principali test di ecotossicologia acquatica

    Energy Technology Data Exchange (ETDEWEB)

    Sanci, Antonella; Rosa, Silvia [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dipt. Ambiente

    1997-09-01

    Bioassay play a crucial role in assessing the actual or potential impacts of anthropogenic agents on the natural environment. In this technical report, literature on bioassays for aquatic ecosystems has been reviewed and classified. Problems associated with the choice and application of bioassays are discussed.

  16. An adaptive nonparametric method in benchmark analysis for bioassay and environmental studies.

    Science.gov (United States)

    Bhattacharya, Rabi; Lin, Lizhen

    2010-12-01

    We present a novel nonparametric method for bioassay and benchmark analysis in risk assessment, which averages isotonic MLEs based on disjoint subgroups of dosages. The asymptotic theory for the methodology is derived, showing that the MISEs (mean integrated squared error) of the estimates of both the dose-response curve F and its inverse F(-1) achieve the optimal rate O(N(-4/5)). Also, we compute the asymptotic distribution of the estimate ζ~p of the effective dosage ζ(p) = F(-1) (p) which is shown to have an optimally small asymptotic variance.

  17. Investigation of independence in inter-animal tumor-type occurrences within the NTP rodent-bioassay database

    Energy Technology Data Exchange (ETDEWEB)

    Bogen, K.T. [Lawrence Livermore National Lab., CA (United States); Seilkop, S. [Analytical Sciences, Inc., Durham, NC (United States)

    1993-05-01

    Statistically significant elevation in tumor incidence at multiple histologically distinct sites is occasionally observed among rodent bioassays of chemically induced carcinogenesis. If such data are to be relied on (as they have, e.g., by the US EPA) for quantitative cancer potency assessment, their proper analysis requires a knowledge of the extent to which multiple tumor-type occurrences are independent or uncorrelated within individual bioassay animals. Although difficult to assess in a statistically rigorous fashion, a few significant associations among tumor-type occurrences in rodent bioassays have been reported. However, no comprehensive studies of animal-specific tumor-type occurrences at death or sacrifice have been conducted using the extensive set of available NTP rodent-bioassay data, on which most cancer-potency assessment for environmental chemicals is currently based. This report presents the results of such an analysis conducted on behalf of the National Research Council`s Committee on Risk Assessment for Hazardous Air Pollutants. Tumor-type associations among individual animals were examined for {approximately}2500 to 3000 control and {approximately}200 to 600 treated animals using pathology data from 62 B6C3F1 mouse studies and 61 F/344N rat studies obtained from a readily available subset of the NTP carcinogenesis bioassay database. No evidence was found for any large correlation in either the onset probability or the prevalence-at-death or sacrifice of any tumor-type pair investigated in control and treated rats and niece, although a few of the small correlations present were statistically significant. Tumor-type occurrences were in most cases nearly independent, and departures from independence, where they did occur, were small. This finding is qualified in that tumor-type onset correlations were measured only indirectly, given the limited nature of the data analyzed.

  18. Fast and accurate semantic annotation of bioassays exploiting a hybrid of machine learning and user confirmation.

    Science.gov (United States)

    Clark, Alex M; Bunin, Barry A; Litterman, Nadia K; Schürer, Stephan C; Visser, Ubbo

    2014-01-01

    Bioinformatics and computer aided drug design rely on the curation of a large number of protocols for biological assays that measure the ability of potential drugs to achieve a therapeutic effect. These assay protocols are generally published by scientists in the form of plain text, which needs to be more precisely annotated in order to be useful to software methods. We have developed a pragmatic approach to describing assays according to the semantic definitions of the BioAssay Ontology (BAO) project, using a hybrid of machine learning based on natural language processing, and a simplified user interface designed to help scientists curate their data with minimum effort. We have carried out this work based on the premise that pure machine learning is insufficiently accurate, and that expecting scientists to find the time to annotate their protocols manually is unrealistic. By combining these approaches, we have created an effective prototype for which annotation of bioassay text within the domain of the training set can be accomplished very quickly. Well-trained annotations require single-click user approval, while annotations from outside the training set domain can be identified using the search feature of a well-designed user interface, and subsequently used to improve the underlying models. By drastically reducing the time required for scientists to annotate their assays, we can realistically advocate for semantic annotation to become a standard part of the publication process. Once even a small proportion of the public body of bioassay data is marked up, bioinformatics researchers can begin to construct sophisticated and useful searching and analysis algorithms that will provide a diverse and powerful set of tools for drug discovery researchers. PMID:25165633

  19. Fast and accurate semantic annotation of bioassays exploiting a hybrid of machine learning and user confirmation

    Directory of Open Access Journals (Sweden)

    Alex M. Clark

    2014-08-01

    Full Text Available Bioinformatics and computer aided drug design rely on the curation of a large number of protocols for biological assays that measure the ability of potential drugs to achieve a therapeutic effect. These assay protocols are generally published by scientists in the form of plain text, which needs to be more precisely annotated in order to be useful to software methods. We have developed a pragmatic approach to describing assays according to the semantic definitions of the BioAssay Ontology (BAO project, using a hybrid of machine learning based on natural language processing, and a simplified user interface designed to help scientists curate their data with minimum effort. We have carried out this work based on the premise that pure machine learning is insufficiently accurate, and that expecting scientists to find the time to annotate their protocols manually is unrealistic. By combining these approaches, we have created an effective prototype for which annotation of bioassay text within the domain of the training set can be accomplished very quickly. Well-trained annotations require single-click user approval, while annotations from outside the training set domain can be identified using the search feature of a well-designed user interface, and subsequently used to improve the underlying models. By drastically reducing the time required for scientists to annotate their assays, we can realistically advocate for semantic annotation to become a standard part of the publication process. Once even a small proportion of the public body of bioassay data is marked up, bioinformatics researchers can begin to construct sophisticated and useful searching and analysis algorithms that will provide a diverse and powerful set of tools for drug discovery researchers.

  20. Soil bioassays as tools for sludge compost quality assessment

    OpenAIRE

    Domene, X.; Solà i Sau, Laura; Ramírez Hernández, Wilson Ariel; Alcañiz, Josep M.; Andrés Pastor, Pilar

    2011-01-01

    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...

  1. Sensitive bioassay for detection of PPAR{alpha} potentially hazardous ligands with gold nanoparticle probe

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Wei; Wan, Yan-Jian [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China); Wang, Xianliang [Division of Environmental Pollution and Human Health, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Yuan-yuan; Yang, Wen-Jie; Wang, Chun-Xiang [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China); Xu, Shun-qing, E-mail: shunqing@mails.tjmu.edu.cn [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China)

    2011-09-15

    Highlights: {yields} We develop a sensitive and high throughput method to screen PPAR{alpha} ligands. {yields} This method is based on the ligand-receptor interaction on microplate. {yields} The sensitivity is increased through sliver enhancement on captured gold nanoparticle probes. {yields} There is a significant correlation between the bioassay and LC-MS for water spiked samples. - Abstract: There are so many kinds of peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) ligands with hazardous effect for human health in the environment, such as certain herbicides, plasticizers and drugs. Among these agonists, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and mono-(2-ethylhexyl) phthalate (MEHP) are mostly investigated due to their persistence and accumulation in environment and their potential toxicity via PPAR{alpha}. This investigation aims at developing a bioassay method to detect PPAR{alpha} ligands based on the ligand-receptor interaction on microplate. PPAR{alpha}, which formed heterodimers with retinoid X receptor-{alpha} (RXR{alpha}), were activated by PPAR{alpha} ligands to form ligands-PPAR{alpha}-RXR{alpha} complexes. Then the complexes were transferred into a microplate and captured via monoclonal anti-PPAR{alpha} antibody. The PPAR{alpha} responsive elements (PPRE) modified-gold nanoparticle probes were captured by the ligand-PPAR{alpha}-RXR{alpha} complexes immobilized on the microplate, and then could be quantified through measuring the optical density after silver enhancement. The results showed that PFOS was quantified with a linear range from 100 pM to 1 {mu}M and the detection limit was 10 pM. In addition to PFOS, PFOA and MEHP were also quantified within a proper range through the proposed bioassay. This bioassay was compared with that of liquid chromatography tandem-mass spectrometry (LC-MS) for water spiked samples with a significant correlation (r = 0.9893). This study provides a high-throughput detection

  2. A Bioassay System Using Bioelectric Signals from Small Fish

    Science.gov (United States)

    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.

  3. Bioassay of circulating luteinizing hormone in the rhesus monkey: comparison with radioimmunoassay during physiological changes

    International Nuclear Information System (INIS)

    The concentration of biologically active LH in Rhesus monkey (Macaca mulatta) serum was measured by a highly sensitive bioassay based upon testosterone production by dispersed rat interstitial cells. The sensitivity of the in vitro bioassay was equal to or higher than that of radioimmunoassay, with detection limits of 0.1 mIU of human menopausal gonadotropin (hMG) or 10 ng of a Rhesus pituitary gonadotropin preparation (LER-1909-2). Parallel dose-response curves were obtained for hMG and Rhesus monkey pituitary gonadotropin. The method permits bioassay of LH in 20--100 μl of serum from adult male monkeys, and from female monkeys during the follicular and luteal phases of the menstrual cycle. Bioactive LH concentrations could be assayed in 0.25 to 5 μl of serum from mid-cycle, postmenopausal, and castrated female monkeys. Serum LH was undetectable in two hypophysectomized adult female monkeys and six intact immature animals, and was 13 +- 6 (SD) mIU/ml in adult male monkeys. In adult females, follicular phase LH levels ranged from 17 to 169 mIU/ml, with a mean of 76 +- 52 mIU/ml. The midcycle LH peak was 1738 +- 742 mIU/ml and the luteal phase values ranged from 6-47 mIU/ml, with a mean of 35 +- 5 mIU/ml. Serum LH concentrations ranged from 100 to 900 mIU/ml in two menopausal females, and from 590--1480 mIU/ml in castrated females. Treatment of castrated female monkeys with estrogen plus progesterone produced an initial two-fold rise in sepum LH within 3 days, followed by a gradual decline to one-fourth to one-tenth of the initial levels after 10 days of treatment. Serum LH was suppressed to undetectable levels during the third week, and remained so for the duration of the 60-day treatment period

  4. Global parameter estimation of the Cochlodinium polykrikoides model using bioassay data

    Institute of Scientific and Technical Information of China (English)

    CHO Hong-Yeon; PARK Kwang-Soon; KIM Sung

    2016-01-01

    Cochlodinium polykrikoides is a notoriously harmful algal species that inflicts severe damage on the aquacultures of the coastal seas of Korea and Japan. Information on their expected movement tracks and boundaries of influence is very useful and important for the effective establishment of a reduction plan. In general, the information is supported by a red-tide (a.k.a algal bloom) model. The performance of the model is highly dependent on the accuracy of parameters, which are the coefficients of functions approximating the biological growth and loss patterns of theC. polykrikoides. These parameters have been estimated using the bioassay data composed of growth-limiting factor and net growth rate value pairs. In the case of theC. polykrikoides, the parameters are different from each other in accordance with the used data because the bioassay data are sufficient compared to the other algal species. The parameters estimated by one specific dataset can be viewed as locally-optimized because they are adjusted only by that dataset. In cases where the other one data set is used, the estimation error might be considerable. In this study, the parameters are estimated by all available data sets without the use of only one specific data set and thus can be considered globally optimized. The cost function for the optimization is defined as the integrated mean squared estimation error, i.e., the difference between the values of the experimental and estimated rates. Based on quantitative error analysis, the root-mean squared errors of the global parameters show smaller values, approximately 25%–50%, than the values of the local parameters. In addition, bias is removed completely in the case of the globally estimated parameters. The parameter sets can be used as the reference default values of a red-tide model because they are optimal and representative. However, additional tuning of the parameters using thein-situ monitoring data is highly required. As opposed to the bioassay

  5. Comparison of Methods of Identifying Helicobacter hepaticus in B6C3F1 Mice Used in a Carcinogenesis Bioassay

    OpenAIRE

    Fox, James G.; MacGregor, Judith A.; Shen, Zeli; Li, Xiantang; Lewis, Robert; Dangler, Charles A.

    1998-01-01

    In a long-term rodent bioassay evaluating the carcinogenicity of triethanolamine, there was equivocal evidence of carcinogenic activity in male B6C3F1 mice, based on a marginal increase in the number of hepatocellular adenomas and hepatoblastomas. Interpretation was complicated by the presence of Helicobacter hepaticus in selected silver-stained liver sections which also had histological evidence of karyomegaly and oval cell hyperplasia. An increase in numbers of liver tumors, as evidence of ...

  6. Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor-LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn.

    Science.gov (United States)

    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.

  7. Bioassays for TSH receptor autoantibodies, from FRTL-5 cells to TSH receptor–LH/CG receptor chimeras: the contribution of Leonard D. Kohn

    Directory of Open Access Journals (Sweden)

    Cesidio Giuliani

    2016-07-01

    Full Text Available 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 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 against the TSH receptor. 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 TSH receptor, the Kohn laboratory constructed human TSH receptor–rat luteinizing hormone/ chorionic gonadotropin receptor chimeras. This paved the way to a new bioassay based on the use of nonthyroid 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 others researchers in TSH receptor molecular biology and TRAbs assay, especially with the development of highly potent monoclonal antibodies. A comparison of the diagnostic accuracies of the main TRAbs assays, as both immunoassays and bioassays, is also provided.

  8. Bioassays for TSH Receptor Autoantibodies, from FRTL-5 Cells to TSH Receptor–LH/CG Receptor Chimeras: The Contribution of Leonard D. Kohn

    Science.gov (United States)

    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

  9. Combined effects of estrogenic chemicals with the same mode of action using an estrogen receptor binding bioassay.

    Science.gov (United States)

    Yang, Rong; Li, Na; Ma, Mei; Wang, Zijian

    2014-11-01

    The increasing amounts of various estrogenic chemicals coexisting in the aquatic environment may pose environmental risks. While the concept of estradiol equivalent (EEQ) has been frequently applied in studying estrogenic mixtures, few experiments have been done to prove its reliability. In this study, the reliability of EEQ and the related model concentration addition (CA) was verified based on the two-hybrid recombinant yeast bioassay when all mixture components had the same mode of action and target of action. Our results showed that the measured estrogenic effects could be well predicted by CA and EEQ for all laboratory-made mixtures using two designs, despite the varying estrogenic activity, concentration levels and ratios of the test chemicals. This suggests that when an appropriate endpoint and its relevant bioassay are chosen, CA should be valid and the application of EEQ in predicting the effect of non-equi-effect mixtures is feasible. PMID:25461542

  10. Terbium to quantum rod Förster resonance energy transfer for homogeneous bioassays with picomolar detection limits

    International Nuclear Information System (INIS)

    We report on the proof-of-principle of using semiconductor nanorods (quantum rods; QRs) in homogeneous Förster resonance energy transfer (FRET) bioassays. Terbium complexes (Tb) with long photoluminescence lifetimes were used as FRET donors, and biological recognition was accomplished by biotin-QR to Tb-streptavidin binding. Time-resolved and steady-state spectroscopy were used to investigate varying relative donor/acceptor concentrations and different lengths of polyethylene glycol (PEG)-based surface coatings. Homogeneous bioassays displayed low picomolar detection limits in 150 μL samples, independent of whether 1 and 10 kDa biotin-PEG-SH surface ligands were used. The results suggest that the combination of Tb-to-QR FRET with time-gated detection may become a powerful tool for homogeneous biosensing. (author)

  11. Addressing the recovery of feeding rates in post-exposure feeding bioassays: Cyathura carinata as a case study

    Energy Technology Data Exchange (ETDEWEB)

    Pais-Costa, Antonia Juliana [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Acevedo, Pelayo [SaBio IREC, Instituto de Investigación en Recursos Cinegéticos (UCLM-CSIC-JCCM), Ciudad Real 13005 (Spain); Marques, João Carlos [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal); Martinez-Haro, Mónica, E-mail: monica.martinezharo@gmail.com [IMAR—Institute of Marine Research, MARE—Marine and Environmental Sciences Centre, Faculty of Sciences and Technology, University of Coimbra, 3004-517 Coimbra (Portugal)

    2015-02-15

    Post-exposure bioassays are used in environmental assessment as a cost-effective tool, but the effects of organism's recovery after exposure to pollutant has not yet been addressed in detail. The recoveries of post-exposure feeding rates after being exposed to two sublethal concentrations of cadmium during two different exposure periods (48 h and 96 h) were evaluated under laboratory conditions using the estuarine isopod Cyathura carinata. Results showed that feeding depression was a stable endpoint up to 24 h after cadmium exposure, which is useful for ecotoxicological bioassays. - Highlights: • We studied recovery of post-exposure feeding rates 48–96 h after cadmium exposure. • The assay is based on the isopod Cyathura carinata. • Post-exposure feeding inhibition is a stable sublethal endpoint.

  12. Comparison of various bioassays for dioxins measurements in fuel gas, fly ash and bottom ash

    Energy Technology Data Exchange (ETDEWEB)

    Ota, S.; Kin-ichi, S. [Ministry of the Environment, Tokyo (Japan); Masatoshi, M.; Shin-ichi, S. [National Institute for Environmental Studies, Tsukuba (Japan)

    2004-09-15

    In Japan, the control standards for dioxins (PCDDs, PCDFs and Co-PCBs) in the emission gas, fly and bottom ashes from waste incinerators have been defined in the Law Concerning Special Measures against Dioxins (Dioxins Law). Based on the Dioxins law, an installation personnel of waste incinerators of specified facilities shall measure dioxins in the emission gas and fly and bottom ashes more than once every year followed by reporting the results to their prefectural governor. The present regulating procedure has been set to use high-resolution gas chromatography/ high-resolution mass spectrometry (HRGC/HRMS, hereafter GC/MS) systems to determine dioxin-concentrations. However, the GC/MS measurements are often money- and timeconsuming, since they need complicated steps for sample preparation, expensive equipments and highly skilled technicians. Therefore, it is of high priority to develop rapid and economical alternative methods to measure dioxins. Recently, various assays using biological reactions have drawn a high degree of attention as a candidate for alternative measurement methods of dioxins. During the past decade several studies demonstrated the utility of a chemical (GC/MS) and biological (bioassays/biomarkers) control of waste thermal recycling processes like pyrolysis or incineration treatment. In this paper, we report the results of our recent examinations on the possibility to apply various bioassays to supplementary methods for the present procedure.

  13. Bioassay-Guided Isolation of Two Flavonoids from Derris scandens with Topoisomerase II Poison Activity.

    Science.gov (United States)

    Sangmalee, Suphattra; Laorpaksa, Areerat; Sritularak, Boonchoo; Sukrong, Suchada

    2016-01-01

    Derris scandens (ROXB.) BENTH. (Fabaceae) is used as an alternative treatment for cancer in Thai traditional medicine. Investigation of the topoisomerase II (Top2) poison of compounds isolated from this plant may reveal new drug leads for the treatment of cancer. Bioassay-guided isolation was performed on an extract of D. scandens stems using a yeast cell-based assay. A yeast strain expressing the top2-1 temperature-sensitive mutant was used to assay Top2 activity. At the permissive temperature of 25°C, yeast cells were highly sensitive to Top2 poison agents. At the semi-permissive temperature of 30°C, where enzyme activity was present but greatly diminished, cells displayed only marginal sensitivity. The bioassay-guided fractionation of the extract led to the isolation of two known isoflavones: 5,7,4'-trihydroxy-6,8-diprenylisoflavone (1) and lupalbigenin (2). These two compounds also displayed cytotoxicity against three different cancer cell lines, KB, MCF-7 and NCI-H187. In conclusion, Top2 poison agents from D. scandens are reported for the first time, substantiating the use of D. scandens in Thai traditional medicine for cancer treatment. PMID:26754253

  14. Evaluation of the response of Clibanarius africanus (Decapoda: Paguridae to crude oil in static bioassay

    Directory of Open Access Journals (Sweden)

    B.J. Oribhabor

    2012-12-01

    Full Text Available The acute toxicity of Nigeria Bonny light crude oil against hermit crab, Cliabanarius africanus of a tidal creek, Eastern Obolo, Akwa Ibom State, Nigeria was investigated in the laboratory under static bioassay. The test crude oil was found to be poorly toxic to the test organism, resulting in delayed mortality and consequent extension of the bioassay to 8 days. Based on the LC50, the toxicity of the test compound was more manifested on the 8 day than at 96 hour, with a toxicity factor showing that the test compound was approximately 12 times, more manifested against C. africanus on the 8 day than at 96 hour. Paired t-test showed that there was no significant difference between 96h LC50 (549.9 ml l-1 and 8d LC50 (45.2 ml l-1. The results of this study indicated that C. africanus is not a good early warning indicator for oil pollution but its response during spills could serve as a good indicator of adverse impact.

  15. Bioassay standardization for the detection of allelopathic compounds and environmental toxicants using lettuce

    Directory of Open Access Journals (Sweden)

    Mateus Salomão Simões

    2013-09-01

    Full Text Available The purpose of this study was to assess different experimental conditions to determine a protocol for bioassays based on seed germination and early seedling growth using lettuce (Lactuca sativa L. cv. Grand Rapids as indicator species. This protocol aims to provide support for the standardization of assays of various chemicals such as allelochemicals and environmental toxicants. The following tests were performed: time of germination, temperature, light, solution volume and Petri dish size. For each test (except for time of germination, the influence of the conditions investigated was determined by the endpoints germination percentage, germination speed index, root length, seedling fresh weight and total dry weight. The results showed that variations in the methods altered the results. It is recommended that bioassays using L. sativa L. cv. Grand Rapids be carried out for a minimum period of four days for assessments of both germination and initial growth and that the experimental conditions include a temperature of 20°C, 90-mm Petri dishes or larger, 0.1 mL cypsela solution, and continuous light or 12-hour photoperiod.

  16. Mimicking Daphnia magna bioassay performance by an electronic tongue for urban water quality control

    Energy Technology Data Exchange (ETDEWEB)

    Kirsanov, Dmitry, E-mail: d.kirsanov@gmail.com [Laboratory of Chemical Sensors, St. Petersburg State University, St. Petersburg (Russian Federation); Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation); Legin, Evgeny [Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation); Sensor Systems LLC, St. Petersburg (Russian Federation); Zagrebin, Anatoly; Ignatieva, Natalia; Rybakin, Vladimir [Institute of Limnology, Russian Academy of Sciences, St. Petersburg (Russian Federation); Legin, Andrey [Laboratory of Chemical Sensors, St. Petersburg State University, St. Petersburg (Russian Federation); Laboratory of Artificial Sensor Systems, ITMO University, St. Petersburg (Russian Federation)

    2014-05-01

    Highlights: • -Daphnia magna bioassay can be simulated with multisensor system. • Urban water toxicity can be predicted from potentiometric ET data. • Independent test set validation confirms statistical significance of the results. - Abstract: Toxicity is one of the key parameters of water quality in environmental monitoring. However, being evaluated as a response of living beings (as their mobility, fertility, death rate, etc.) to water quality, toxicity can only be assessed with the help of these living beings. This imposes certain restrictions on toxicity bioassay as an analytical method: biotest organisms must be properly bred, fed and kept under strictly regulated conditions and duration of tests can be quite long (up to several days), thus making the whole procedure the prerogative of the limited number of highly specialized laboratories. This report describes an original application of potentiometric multisensor system (electronic tongue) when the set of electrochemical sensors was calibrated against Daphnia magna death rate in order to perform toxicity assessment of urban waters without immediate involvement of living creatures. PRM (partial robust M) and PLS (projections on latent structures) regression models based on the data from this multisensor system allowed for prediction of toxicity of unknown water samples in terms of biotests but in the fast and simple instrumental way. Typical errors of water toxicity predictions were below 20% in terms of Daphnia death rate which can be considered as a good result taking into account the complexity of the task.

  17. Using marine bioassays to classify the toxicity of Dutch harbor sediments.

    Science.gov (United States)

    Stronkhorst, Joost; Schipper, Cor; Brils, Jos; Dubbeldam, Marco; Postma, Jaap; van de Hoeven, Nelly

    2003-07-01

    A procedure was developed to assess contaminated marine sediments from Dutch harbors for possible adverse biological effects using three laboratory bioassays: A 10-d survival test with the amphipod Corophium volutator, a 14-d survival test with the heart urchin Echinocardium cordatum (adults), and the bioluminescence inhibition test with the bacterium Vibrio fischeri (Microtox solid phase test LSP]). Microtox results were mathematically corrected for the modifying influence of fine sediment particles. After a validation procedure on test performance and modifying factors, respectively, 81%, 99%, and 90% of the amphipod, heart urchin, and Microtox results were approved. Lower and upper threshold limits for biological effects were set at respectively 24 and 30% mortality for C. volutator, 27 and 35% mortality for E. cordatum, and 24 and 48 toxic units for the Microtox SP based on significant differences with control sediment and the performance of reference sediments. The bioassays clearly distinguished harbor sediments that give rise to acute effects and those that do not. Threshold limits for the amphipods, heart urchins, and bacteria were exceeded in, respectively, 9 to 17%, 33 to 40%, and 23 to 50% of the sediment samples. Highest effects were observed in sediments from the northerly harbors; there was significantly less response in sediments from the Delta Region and the port of Rotterdam (The Netherlands). The procedure outlined in this paper can be used for routine screening of contaminated dredged material that is proposed for open water disposal. PMID:12836979

  18. Assessment of the environmental quality of coastal sediments by using a combination of in vitro bioassays.

    Science.gov (United States)

    Pérez-Albaladejo, Elisabet; Rizzi, Juliane; Fernandes, Denise; Lille-Langøy, Roger; Karlsen, Odd André; Goksøyr, Anders; Oros, Andra; Spagnoli, Federico; Porte, Cinta

    2016-07-15

    The environmental quality of marine sediments collected in the area of influence of the Po and Danube Rivers was assessed by using a battery of bioassays based on the use of PLHC-1 cells, zebrafish-Pxr-transfected COS-7 cells, and sea bass ovarian subcellular fractions. This allowed the determination of multiple endpoints, namely, cytotoxicity, oxidative stress, induction of CYP1A, activation of zebrafish Pxr and inhibition of ovarian aromatase. Organic extracts of sediments influenced by the Danube River and collected near harbors and urban discharges showed significant cytotoxicity, CYP1A induction and inhibition of aromatase activity. An analogous response of CYP1A induction and zfPxr activation was observed, which suggests the existence of common ligands of AhR and PXR in the sediment extracts. The study highlights the usefulness of the selected bioassays to identify those sediments that could pose a risk to aquatic organisms and that require further action in order to improve their environmental quality. PMID:27207027

  19. Bioassay and characterization of soil microorganisms involved in the biodegradation of the fungicide, metalaxyl

    International Nuclear Information System (INIS)

    A sensitive bioassay was developed to detect low concentrations of metalaxyl in soils. The quantitative estimation of metalaxyl in soils was based on a significant positive relationship between the radial growth of Phytophthora boehmeriae and the log concentration of the fungicide in the agar. The isolate of P. boehmeriae was chosen for its sensitivity to metalaxyl as manifested in a linear growth response on cornmeal agar over a range of 2 to 30 ng/ml. The sensitivity and quantitative nature of the bioassay was confirmed by comparison with data obtained by using 14C-metalaxyl. Metabolism of metalaxyl was detected in three of five avocado soils that had repeated applications of the fungicide over 2-5 yr. The average disappearance of metalaxyl was 28 days, and in the most active soils was 14 days. The composition and level of the microbial populations of soils, either active or inactive in the breakdown of metalaxyl, did not differ. Fungal and bacterial microflora recovered from these two soils by use of either selective media or filtration techniques were capable of metabolizing metalaxyl over a 45-day period

  20. High-throughput tri-colour flow cytometry technique to assess Plasmodium falciparum parasitaemia in bioassays

    DEFF Research Database (Denmark)

    Tiendrebeogo, Regis W; Adu, Bright; Singh, Susheel K;

    2014-01-01

    BACKGROUND: Unbiased flow cytometry-based methods have become the technique of choice in many laboratories for high-throughput, accurate assessments of malaria parasites in bioassays. A method to quantify live parasites based on mitotracker red CMXRos was recently described but consistent...... distinction of early ring stages of Plasmodium falciparum from uninfected red blood cells (uRBC) remains a challenge. METHODS: Here, a high-throughput, three-parameter (tri-colour) flow cytometry technique based on mitotracker red dye, the nucleic acid dye coriphosphine O (CPO) and the leucocyte marker CD45......-colour technique is rapid, cost effective and robust with comparable sensitivity to microscopy and capable of discriminating between live and dead and/or compromised parasites. Staining for CD45 improved parasitaemia estimates in ADCI assay since high numbers of leucocytes interfered with the accurate...

  1. Fluorescent bioassays for toxic metals in milk and yoghurt

    Directory of Open Access Journals (Sweden)

    Siddiki Mohammad Shohel

    2012-10-01

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

  2. Application of the proposed new ICRP lung model to bioassay

    International Nuclear Information System (INIS)

    The new lung model being proposed by ICRP for use in radiation protection dosimetry requires the calculation of doses to separate regions of the respiratory tract, multiplying these doses by factors proportional to the risk per unit dose to each region, and summing over all regions of the lung to give a ''weighted'' lung dose. This paper compares the doses that would be calculated form bioassay measurements using the new model with those calculated using the current model, which essentially uses total lung burden to estimate lung dose

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

    OpenAIRE

    Jun Zhang; Jui-Hua Hsieh; Hao Zhu

    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...

  4. Applications of the Poly-K Statistical Test to Life-Time Cancer Bioassay Studies

    OpenAIRE

    Gebregziabher, Mulugeta; Hoel, David

    2009-01-01

    The statistical analysis of cancer bioassay data has historically depended on the pathological determination of the experimental animal's cause of death. The poly-k statistical test has provided a method of statistical analysis of animal bioassay data without the need for cause of death information. The test has been shown to have good statistical properties in the typical 2-year cancer bioassay. However, while the poly-k test has been applied to chronic lifetime animal studies, it has not be...

  5. A novel bioassay for the activity determination of therapeutic human brain natriuretic peptide (BNP.

    Directory of Open Access Journals (Sweden)

    Lei Yu

    Full Text Available BACKGROUND: Recombinant human brain natriuretic peptide (rhBNP is an important peptide-based therapeutic drug indicated for the treatment of acute heart failure. Accurate determination of the potency of therapeutic rhBNP is crucial for the safety and efficacy of the drug. The current bioassay involves use of rabbit aortic strips, with experiments being complicated and time-consuming and markedly variable in results. Animal-less methods with better precision and accuracy should be explored. We have therefore developed an alternative cell-based assay, which relies on the ability of BNP to induce cGMP production in HEK293 cells expressing BNP receptor guanylyl cyclase-A. METHODOLOGY/PRINCIPAL FINDINGS: An alternative assay based on the measurement of BNP-induced cGMP production was developed. Specifically, the bioassay employs cells engineered to express BNP receptor guanylyl cyclase-A (GCA. Upon rhBNP stimulation, the levels of the second messager cGMP in these cells drastically increased and subsequently secreted into culture supernatants. The quantity of cGMP, which corresponds to the rhBNP activity, was determined using a competitive ELISA developed by us. Compared with the traditional assay, the novel cell-based assay demonstrated better reproducibility and precision. CONCLUSION/SIGNIFICANCE: The optimized cell-based assay is much simpler, more rapid and precise compared with the traditional assay using animal tissues. To our knowledge, this is the first report on a novel and viable alternative assay for rhBNP potency analysis.

  6. Analytical methods in bioassay-directed investigations of mutagenicity of air particulate material.

    Science.gov (United States)

    Marvin, Christopher H; Hewitt, L Mark

    2007-01-01

    The combination of short-term bioassays and analytical chemical techniques has been successfully used in the identification of a variety of mutagenic compounds in complex mixtures. Much of the early work in the field of bioassay-directed fractionation resulted from the development of a short-term bacterial assay employing Salmonella typhimurium; this assay is commonly known as the Ames assay. Ideally, analytical methods for assessment of mutagenicity of any environmental matrix should exhibit characteristics including high capacity, good selectivity, good analytical resolution, non-destructiveness, and reproducibility. A variety of extraction solvents have been employed in investigations of mutagenicity of air particulate; sequential combination of dichloromethane followed by methanol is most popular. Soxhlet extraction has been the most common extraction method, followed by sonication. Attempts at initial fractionation using different extraction solvents have met with limited success and highlight the need for fractionation schemes applicable to moderately polar and polar mutagenic compounds. Fractionation methods reported in the literature are reviewed according to three general schemas: (i) acid/base/neutral partitioning followed by fractionation using open-column chromatography and/or HPLC; (ii) fractionation based on normal-phase (NP) HPLC using a cyanopropyl or chemically similar stationary phase; and (iii) fractionation by open-column chromatography followed by NP-HPLC. The HPLC methods may be preparative, semi-preparative, or analytical scale. Variations based on acid/base/neutral partitioning followed by a chromatographic separation have also been employed. Other lesser-used approaches involve fractionation based on ion-exchange and thin-layer chromatographies. Although some of the methodologies used in contemporary studies of mutagenicity of air particulate do not represent significant advances in technology over the past 30 years, their simplicity, low

  7. Screening for estrogen residues in calf urine: Comparison of a validated yeast estrogen bioassay and gas chromatography-tandem mass spectrometry

    NARCIS (Netherlands)

    Nielen, M.W.F.; Bovee, T.F.H.; Heskamp, H.H.; Lasaroms, J.J.P.; Sanders, M.B.; Rhijn, van J.A.; Groot, M.J.; Hoogenboom, L.A.P.

    2006-01-01

    Within the European Union, the control for residues of illegal hormones in food-producing animals is based on urine analysis for a few target analytes using gas chromatography/mass spectrometry and/or liquid chromatography¿tandem mass spectrometry. Recently, we developed a robust yeast bioassay scre

  8. Monitoring resistance to Bacillus thuringiensis subsp. israelensis in the field by performing bioassays with each Cry toxin separately

    Directory of Open Access Journals (Sweden)

    Guillaume Tetreau

    2013-11-01

    Full Text Available Bacillus thuringiensis subsp. israelensis (Bti is increasingly used worldwide for mosquito control and is the only larvicide used in the French Rhône-Alpes region since decades. The artificial selection of mosquitoes with field-persistent Bti collected in breeding sites from this region led to a moderate level of resistance to Bti, but to relatively high levels of resistance to individual Bti Cry toxins. Based on this observation, we developed a bioassay procedure using each Bti Cry toxin separately to detect cryptic Bti-resistance evolving in field mosquito populations. Although no resistance to Bti was detected in none of the three mosquito species tested (Aedes rusticus, Aedes sticticus and Aedes vexans, an increased tolerance to Cry4Aa (3.5-fold and Cry11Aa toxins (8-fold was found in one Ae. sticticus population compared to other populations of the same species, suggesting that resistance to Bti may be arising in this population. This study confirms previous works showing a lack of Bti resistance in field mosquito populations treated for decades with this bioinsecticide. It also provides a first panorama of their susceptibility status to individual Bti Cry toxins. In combination with bioassays with Bti, bioassays with separate Cry toxins allow a more sensitive monitoring of Bti-resistance in the field.

  9. LIFE CYCLE BIOASSAY FOR ASSESSMENT OF THE EFFECTS OF TOXIC CHEMICALS USING RAPID CYCLING OF BRASSICA

    Science.gov (United States)

    Initial evaluation of a new plant life cycle bioassay for the assessment of the effects of toxic chemicals is presented. he bioassay features a rapid cycling Brassica species that can complete its life cycle in as little as 36 days. he herbicide dalapon (2,2 dichloropropionic aci...

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

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available 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.

  11. The CALUX bioassay: current status of its application to screening food and feed

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.; Goeyens, L.; Carbonnelle, S.; Loco, van J.; Beernaert, H.; Baeyens, W.; Traag, W.A.; Bovee, T.F.H.; Jacobs, G.; Schoeters, G.

    2006-01-01

    The CALUX bioassay is at present the best screening method for dioxins and dioxin-like (dl) polychlorinated biphenyls (PCBs) in food and feed, and the only assay used in routine monitoring and during larger incidents. Furthermore, the use of bioassays in addition to chemical reference methods allows

  12. Applicability of the CALUX bioassay for screening of dioxin levels in human milk samples

    DEFF Research Database (Denmark)

    Laier, P.; Cederberg, Tommy Licht; Larsen, John Christian;

    2003-01-01

    and applied for monitoring levels of dioxins in human milk samples. Combination effects of dioxin-like compounds were evaluated by testing potential mechanisms of interaction between seven of the major dioxin-like compounds in human milk using the isobole method. Results showed that the compounds acted......The CALUX (chemically activated luciferase expression) bioassay based on rat hepatoma (H4IIE) cells is a sensitive assay for the detection of Ah receptor agonists like 2,3,7,8-substituted chlorinated dibenzo-p-dioxins and dibenzofurans and related PCBs. In this paper, the assay was optimized...... additively, indicating that the usual assumption of additivity in the risk assessment process is valid. In general the relative potencies (REPs) of the single agents were in accordance with their TEFs assigned by the World Health Organisation, except for the mono-ortho-substituted PCB118 that had a 40-fold...

  13. Development of An ICR Mouse Bioassay for Toxicity Evaluatition in Neurotoxic Poistioning Toxins-Ctiontaminated Shellfish

    Institute of Scientific and Technical Information of China (English)

    WONG Chun Kwan; HUNG Patricia; KAM Kai Man

    2013-01-01

    Objective To develop an ICR (female) mouse bioassay (MBA) for toxicity ctionfirmatition and evaluatition of neurotoxins (brevetoxins)-ctiontaminated shellfish. Methods Brevetoxins (BTX-B) as a causative agent of neurotoxic shellfish poistioning (NSP) under different shellfish matrices were intraperittioneally injected at different doses into mice to study their toxic effects and to differentiate the range of lethal and sublethal dosages. Their sensitivity and specificity were analyzed with 2 competitive ELISA kits for quantitative determinatition of standard BTX-B and dihydroBTX-B under different shellfish matrix-diluent combinatitions. Detectition rates of MBA and two antibody-based assays for BTX-B from field NSP-positive shellfish samples were compared. Results BTX-B could be detected in shellfish tissues at ctioncentratition of 50-400 μg/100 g under shellfish matrix-Tween-saline media, which were appropriate to identify toxic shellfish at or above the regulatory limit (80 μg/100 g shellfish tissues). The LD50 identified was 455 μg/kg for BTX-B under general shellfish matrices (excluding oyster matrices) dissolved in Tween-saline. The presence of shellfish matrices, of oyster matrices in particular, retarded the occurrence of death and toxicity presentatition in mice. Two antibody-based assays, even in the presence of different shellfish matrix-diluent combinatitions, showed acceptable results in quantifying BTX-B and dihydroBTX-B well below the regulatory limit. Ctionclusition The two ELISA analyses agree favorably (correlatition coefficient, r≥0.96;Student's t-tests, P>0.05) with the developed bioassay.

  14. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils.

    Science.gov (United States)

    Lors, Christine; Ponge, Jean-François; Martínez Aldaya, Maite; Damidot, Denis

    2011-10-01

    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox(®) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. PMID:21570756

  15. Neotropical electric fishes (Gymnotiformes) as model organisms for bioassays

    Institute of Scientific and Technical Information of China (English)

    Milena Ferreira; Isac Silva de Jesus; Eliana Feldberg; JoséAntônioAlves-Gomes

    2015-01-01

    Electric fishes (Gymnotiformes) inhabit Central and South America and form a relatively large group with more than 200 species. Besides a taxonomic challenge due to their still unresolved systematic, wide distribution and the variety of habitats they occupy, these fishes have been intensively studied due to their peculiar use of bioelectricity for electrolocation and communication. Conventional analysis of cells, tissues and organs have been complemented with the studies on the electric organ discharges of these fishes. This review compiles the results of 13 bioassays developed during the last 50 years, which used the quickness, low costs and functionality of the bioelectric data collection of Gymnotiformes to evaluate the effects of environmental contaminants and neuroactive drugs.

  16. Bioassay techniques for 55Fe in urine samples

    International Nuclear Information System (INIS)

    Solvent extraction, ion chromatography and several rapid screening methods were developed and evaluated for 55Fe bioassay applications. Isopropyl ether and TNOA column extractions had radiochemical recoveries exceeding 90%. These were very reproducible with a coefficient of variation less than 5%. Screening techniques investigated included direct counting of ashed urine solids, and Fe(OH)3. precipitated from urine. The sensitivities (2-50 Bq/d urine) of the screening methods were usually limited by the effective urine volume that could be counted in a liquid scintillation counter. The reference isopropyl ether and chromatography methods could easily achieve sensitivities well below the 1 Bq/d urine output target. (author). 49 refs., 3 tabs., 5 figs

  17. Seroprevalensi Toxoplasma gondii pada Kambing dan Bioassay Patogenitasnya pada Kucing

    Directory of Open Access Journals (Sweden)

    Ni Made Yunik Novita Dewi Dewi

    2013-11-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE The study aimed to determine seroprevalence of Toxoplasmosis in goats sloughtered at Kampung Jawa, Denpasar, Bali and to evaluate their pathogenicities through bioassay in cats.One hundred serums and meats of goats were collected. Anti-Toxoplasma gondii antibody was determined using Indirect Haemaglutination (IHA test. The pathogenicity bioassay of Toxoplasma gondii was carried out through inoculating the meats of goats which had seropositive of Toxoplasma gondii to the cats. The pathogenicity was evaluated using the intensity of oocyte sheding from the cats. The result showed that the seroprevalence of Toxoplasmosis was 46%. There was not significant difference between pathogenicity of Toxoplasma gondii in cat inoculated with meat of goat which had a high and low titer of antibody against Toxoplasma gondii. /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; text-align:justify; line-height:150%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;}

  18. Comparison of solid and liquid-phase bioassays using ecoscores to assess contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Lors, Christine [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France); Centre National de Recherche sur les Sites et Sols Pollues, 930 Boulevard Lahure, BP 537, 59505 Douai Cedex (France); Ponge, Jean-Francois, E-mail: ponge@mnhn.fr [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Martinez Aldaya, Maite [Museum National d' Histoire Naturelle, Departement Ecologie et Gestion de la Biodiversite, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Damidot, Denis [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, LGCgE-MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France)

    2011-10-15

    Bioassays on aqueous and solid phases of contaminated soils were compared, belonging to a wide array of trophic and response levels and using ecoscores for evaluating ecotoxicological and genotoxicological endpoints. The method was applied to four coke factory soils contaminated mainly with PAHs, but also to a lesser extent by heavy metals and cyanides. Aquatic bioassays do not differ from terrestrial bioassays when scaling soils according to toxicity but they are complementary from the viewpoint of ecological relevance. Both aquatic and terrestrial endpoints are strongly correlated with concentrations of 3-ring PAHs. This evaluation procedure allows us to propose a cost-effective battery which embraces a wide array of test organisms and response levels: it includes two rapid bioassays (Microtox) and springtail avoidance), a micronucleus test and three bioassays of a longer duration (algal growth, lettuce germination and springtail reproduction). This battery can be recommended for a cost-effective assessment of polluted/remediated soils. - Highlights: > Comparison of liquid- and solid-phase bioassays on contaminated soils, using ecoscores. > Complementarity of liquid- and solid-phase bioassays for the evaluation of environmental hazards. > Proposal for a restricted battery of 5 most sensitive tests. > Use of this restricted battery for a cost-effective assessment of polluted/remediated soils. - Aqueous and solid phases of contaminated soils give similar results in terms of toxicity but are complementary for the evaluation of environmental hazards by ecoscores.

  19. Establishment of a bioassay for the toxicity evaluation and quality control of Aconitum herbs

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Yi [Integrative Medicine Center, 302 Military Hospital, Beijing 100039 (China); Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500 (China); Wang, Jia-bo, E-mail: pharm_sci@126.com [China Military Institute of Chinese Materia Medica, 302 Military Hospital, Beijing 100039 (China); Zhao, Yan-ling; Shan, Li-mei [Integrative Medicine Center, 302 Military Hospital, Beijing 100039 (China); Li, Bao-cai [Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500 (China); Fang, Fang; Jin, Cheng [Integrative Medicine Center, 302 Military Hospital, Beijing 100039 (China); Xiao, Xiao-he, E-mail: pharmacy302@126.com [Integrative Medicine Center, 302 Military Hospital, Beijing 100039 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer A new bioassay was optimized to evaluate the toxicity of Aconitum herbs. Black-Right-Pointing-Pointer Characterizing total toxicity is its unique advantage over chemical analysis methods. Black-Right-Pointing-Pointer The application of this bioassay promotes the safe use of Aconitum herbs in clinic. - Abstract: Currently, no bioassay is available for evaluating the toxicity of Aconitum herbs, which are well known for their lethal cardiotoxicity and neurotoxicity. In this study, we established a bioassay to evaluate the toxicity of Aconitum herbs. Test sample and standard solutions were administered to rats by intravenous infusion to determine their minimum lethal doses (MLD). Toxic potency was calculated by comparing the MLD. The experimental conditions of the method were optimized and standardized to ensure the precision and reliability of the bioassay. The application of the standardized bioassay was then tested by analyzing 18 samples of Aconitum herbs. Additionally, three major toxic alkaloids (aconitine, mesaconitine, and hypaconitine) in Aconitum herbs were analyzed using a liquid chromatographic method, which is the current method of choice for evaluating the toxicity of Aconitum herbs. We found that for all Aconitum herbs, the total toxicity of the extract was greater than the toxicity of the three alkaloids. Therefore, these three alkaloids failed to account for the total toxicity of Aconitum herbs. Compared with individual chemical analysis methods, the chief advantage of the bioassay is that it characterizes the total toxicity of Aconitum herbs. An incorrect toxicity evaluation caused by quantitative analysis of the three alkaloids might be effectively avoided by performing this bioassay. This study revealed that the bioassay is a powerful method for the safety assessment of Aconitum herbs.

  20. Evaluation on the Joint Action Between Chlorsulfuron and Haloxyfop-R by Bioassay

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The joint action between chlorsulfuron and haloxyfop-R was evaluated by bioassay with wheat and com.respectivly. The dose-response curve derived from wheat bioassay showed that the inhibition of haloxyfop-Rto wheat root growth wasn't affected by the increasing rate of chlorsulfuron. It indicated that chlorsulfuron had no antagonism to haloxyfop-R. Meanwhile ,the variation analysis of corn bioassay indicated that these two herbicides had joint action on inhibition to corn primary root growth. The joint action was evaluated as addis tive action by using Isobole Method. So chlorsulfuron and haloxyfop-R could be used as tank mixture.

  1. Antioxidant, antimicrobial and cytotoxic bioassay of Mollugo oppositifolius L

    Directory of Open Access Journals (Sweden)

    Md. Torequl Islam

    2011-01-01

    Full Text Available The present study was conducted according to the traditional uses of Mollugo oppositifolius L. by the kabiraj (traditional practioner for the treatment of infectious diseases of the ill fated and poor people of Bangladesh. For this antioxidant, antimicrobial and biolethality potentials were conducted by methanol (MOME, ethanol (MOEE and petroleum ether (MOPE extractives of the suspected species. To determine the antioxidant activity the DPPH inhibition method was used. For antimicrobial test, antibacterial and antifungal sensitivities were performed by disc diffusion method and serial tube dilution method was carried out to determine the minimum inhibitory concentrations on some human pathogenic bacteria and fungi. For cytotoxicity test, brine shrimp lethality bioassay was conducted. Among the three crude extracts, MOEE produced more significant inhibition of DPPH (IC 50 ; 27 μg/ml; MOPE produced highest zone of inhibition against Bacillus subtilis (16.67 mm and Microsporum spp. (16.0 mm. On the other hand, MOME produced mild cytotoxicity as 50% and 90% mortality (LC 50 and LC 90 8.0 μg/ml and 85.12 μg/ml.

  2. Analyzing bioassay data using Bayesian methods -- A primer

    Energy Technology Data Exchange (ETDEWEB)

    Miller, G.; Inkret, W.C.; Schillaci, M.E.

    1997-10-16

    The classical statistics approach used in health physics for the interpretation of measurements is deficient in that it does not allow for the consideration of needle in a haystack effects, where events that are rare in a population are being detected. In fact, this is often the case in health physics measurements, and the false positive fraction is often very large using the prescriptions of classical statistics. Bayesian statistics provides an objective methodology to ensure acceptably small false positive fractions. The authors present the basic methodology and a heuristic discussion. Examples are given using numerically generated and real bioassay data (Tritium). Various analytical models are used to fit the prior probability distribution, in order to test the sensitivity to choice of model. Parametric studies show that the normalized Bayesian decision level k{sub {alpha}}-L{sub c}/{sigma}{sub 0}, where {sigma}{sub 0} is the measurement uncertainty for zero true amount, is usually in the range from 3 to 5 depending on the true positive rate. Four times {sigma}{sub 0} rather than approximately two times {sigma}{sub 0}, as in classical statistics, would often seem a better choice for the decision level.

  3. Tobacco specific N-nitrosamines: occurrence and bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Hoffmann, D.; Adams, J.D.; Brunnemann, K.D.; Rivenson, A.; Hecht, S.S.

    1982-01-01

    A new GC-TEA method for the analysis of tobacco-specific N-nitrosamines (TSNA) has been developed. Four TSNA have thus far been identified; these are N'-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), N'-nitrosoanatabine (NAT) and N'-nitrosoanabasine (NAB). The method is currently being applied to the development of cigarette filter-tips which will selectively remove these carcinogens from cigarette smoke. Since recent epidemiological studies have established a correlation between snuff dipping and oral cancer, we have analysed leading snuff brands for TSNA. Snuff products from Sweden, Denmark, Bavaria and the USA contained 5-106 mg/kg of the TSNA and the saliva of snuff dippers had TSNA levels of 20-890 micrograms/kg. NNN, NNK and NAB induce benign and malignant tumours of the respiratory tract of mice and rats. We have shown that NNN and NNK induce tumours in the upper respiratory tract of hamsters and that NNK is the most active carcinogen of the TSNA, also inducing adenoma and adenocarcinoma in the hamster lung. The reported chemical analyses and bioassay results support the epidemiological findings on the causal association of tobacco use and cancer in man.

  4. Comparison of solid-phase bioassays and ecoscores to evaluate the toxicity of contaminated soils.

    Science.gov (United States)

    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. PMID:20537453

  5. Phototoxicity activity of Psoralea drupacea L. using Atremia salina bioassay system

    Directory of Open Access Journals (Sweden)

    Mohammad Ramezani

    2011-07-01

    Conclusion: The result showed that P. drupacea methanolic extract and chloroform fraction have phototoxicity in A. salina bioassay system and their toxic effect is related to phototoxic constituents such as psoralen.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ferrao-Filho, Aloysio da S., E-mail: aloysio@ioc.fiocruz.b [Laboratorio de Avaliacao e Promocao da Saude Ambiental, Departamento de Biologia, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, Rio de Janeiro, RJ 21045-900 (Brazil); Soares, Maria Carolina S., E-mail: mcarolsoares@gmail.co [Departamento de Engenharia Sanitaria e Ambiental Faculdade de Engenharia, Universidade Federal de Juiz de Fora, Juiz de Fora, MG 36036-900 (Brazil); Freitas de Magalhaes, Valeria, E-mail: valeria@biof.ufrj.b [Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Rio de Janeiro, RJ 21949-900 (Brazil); Azevedo, Sandra M.F.O., E-mail: sazevedo@biof.ufrj.b [Laboratorio de Ecofisiologia e Toxicologia de Cianobacterias, Instituto de Biofisica Carlos Chagas Filho, CCS, Universidade Federal do Rio de Janeiro, Ilha do Fundao, Rio de Janeiro, RJ 21949-900 (Brazil)

    2010-06-15

    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 (ET{sub 50}) was adopted as the endpoint. Paralysis of swimming movements was observed between approx0.5-3 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 ET{sub 50}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. - A new Daphnia bioassay, as an alternative to the mouse bioassay, is able to detect effects of fast-acting, potent neurotoxins in raw water.

  7. Bioassay of thermal protection afforded by candidate flight suit fabrics.

    Science.gov (United States)

    Knox, F S; Wachtel, T L; McCahan, G R

    1979-10-01

    The United States Army Aeromedical Research Laboratory (USAARL) porcine cutaneous bioassay technique was used to determine what mitigating effect four thermally protective flight suit fabrics would have on fire-induced skin damage. The fabrics were 4.8-ox twill weave Nomex aramide, 4.5-oz stabilized twill weave polybenzimidazole, 4.8-oz plain weave experimental high-temperature polymer (HT4), and 4.8-oz plain weave Nomex aramide (New Weave Nomex or NWN). Each fabric sample was assayed 20 times in each of four configurations: as a single layer in contact with the skin; as a single layer with a 6.35 mm (0.25 in) air gap between fabric and skin; in conjuction with a cotton T-shirt with no air gaps; and, finally, in conjuction with a T-shirt with a 6.35 mm air gap between T-shirt and fabric. Bare skin was used as a control. A JP-4 fueled furnace was used as a thermal source and was adjested to deliver a mean heat flux of 3.07 cal/cm2/s. The duration of exposure was 5 s. Four hundred burn sites were graded using clinical observation and microscopic techniques. Used as single layers, none of the fabrics demonstrated superiority in providing clinically significant protection. When used with a cotton T-shirt, protection was improved. Protection improved progressively for all fabrics and configuration when an air gap was introduced. The experimental high-temperature polymer consistently demonstrated lower heat flux transmission in all configurations, but did not significantly reduce clinical burns. PMID:518445

  8. Plasmonically amplified bioassay - Total internal reflection fluorescence vs. epifluorescence geometry.

    Science.gov (United States)

    Hageneder, Simone; Bauch, Martin; Dostalek, Jakub

    2016-08-15

    This paper investigates plasmonic amplification in two commonly used optical configurations for fluorescence readout of bioassays - epifluorescence (EPF) and total internal reflection fluorescence (TIRF). The plasmonic amplification in the EPF configuration was implemented by using crossed gold diffraction grating and Kretschmann geometry of attenuated total reflection method (ATR) was employed in the TIRF configuration. Identical assay, surface architecture for analyte capture, and optics for the excitation, collection and detection of emitted fluorescence light intensity were used in both TIRF and EPF configurations. Simulations predict that the crossed gold diffraction grating (EPF) can amplify the fluorescence signal by a factor of 10(2) by the combination of surface plasmon-enhanced excitation and directional surface plasmon-coupled emission in the red part of spectrum. This factor is about order of magnitude higher than that predicted for the Kretschmann geometry (TIRF) which only took advantage of the surface plasmon-enhanced excitation. When applied for the readout of sandwich interleukin 6 (IL-6) immunoassay, the plasmonically amplified EPF geometry designed for Alexa Fluor 647 labels offered 4-times higher fluorescence signal intensity compared to TIRF. Interestingly, both geometries allowed reaching the same detection limit of 0.4pM despite of the difference in the fluorescence signal enhancement. This is attributed to inherently lower background of fluorescence signal for TIRF geometry compared to that for EPF which compensates for the weaker fluorescence signal enhancement. The analysis of the inflammation biomarker IL-6 in serum at medically relevant concentrations and the utilization of plasmonic amplification for the fluorescence measurement of kinetics of surface affinity reactions are demonstrated for both EPF and TIRF readout. PMID:27260457

  9. Plasmonically amplified bioassay - Total internal reflection fluorescence vs. epifluorescence geometry.

    Science.gov (United States)

    Hageneder, Simone; Bauch, Martin; Dostalek, Jakub

    2016-08-15

    This paper investigates plasmonic amplification in two commonly used optical configurations for fluorescence readout of bioassays - epifluorescence (EPF) and total internal reflection fluorescence (TIRF). The plasmonic amplification in the EPF configuration was implemented by using crossed gold diffraction grating and Kretschmann geometry of attenuated total reflection method (ATR) was employed in the TIRF configuration. Identical assay, surface architecture for analyte capture, and optics for the excitation, collection and detection of emitted fluorescence light intensity were used in both TIRF and EPF configurations. Simulations predict that the crossed gold diffraction grating (EPF) can amplify the fluorescence signal by a factor of 10(2) by the combination of surface plasmon-enhanced excitation and directional surface plasmon-coupled emission in the red part of spectrum. This factor is about order of magnitude higher than that predicted for the Kretschmann geometry (TIRF) which only took advantage of the surface plasmon-enhanced excitation. When applied for the readout of sandwich interleukin 6 (IL-6) immunoassay, the plasmonically amplified EPF geometry designed for Alexa Fluor 647 labels offered 4-times higher fluorescence signal intensity compared to TIRF. Interestingly, both geometries allowed reaching the same detection limit of 0.4pM despite of the difference in the fluorescence signal enhancement. This is attributed to inherently lower background of fluorescence signal for TIRF geometry compared to that for EPF which compensates for the weaker fluorescence signal enhancement. The analysis of the inflammation biomarker IL-6 in serum at medically relevant concentrations and the utilization of plasmonic amplification for the fluorescence measurement of kinetics of surface affinity reactions are demonstrated for both EPF and TIRF readout.

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

    Science.gov (United States)

    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

  11. Bioassay-Guided Isolation and Structural Modification of the Anti-TB Resorcinols from Ardisia gigantifolia.

    Science.gov (United States)

    Guan, Yi-Fu; Song, Xun; Qiu, Ming-Hua; Luo, Shi-Hong; Wang, Bao-Jie; Van Hung, Nguyen; Cuong, Nguyen M; Soejarto, Djaja Doel; Fong, Harry H S; Franzblau, Scott G; Li, Sheng-Hong; He, Zhen-Dan; Zhang, Hong-Jie

    2016-08-01

    Tuberculosis (TB) is a highly contagious disease mainly caused by Mycobacterium tuberculosis H37 RV . Antitubercular (anti-TB) bioassay-guided isolation of the CHCl3 extract of the leaves and stems of the medicinal plant Ardisia gigantifolia led to the isolation of two anti-TB 5-alkylresorcinols, 5-(8Z-heptadecenyl) resorcinol (1) and 5-(8Z-pentadecenyl) resorcinol (2). We further synthesized 15 derivatives based on these two natural products. These compounds (natural and synthetic) were evaluated for their anti-TB activity against Mycobacterium tuberculosis H37 RV . Resorcinols 1 and 2 exhibited anti-TB activity with MIC values at 34.4 and 79.2 μm in MABA assay, respectively, and 91.7 and 168.3 μm in LORA assay, respectively. Among these derivatives, compound 8 was found to show improved anti-TB activity than its synthetic precursor (2) with MIC values at 42.0 μm in MABA assay and 100.2 μm in LORA assay. The active compounds should be regarded as new hits for further study as a novel class of anti-TB agents. The distinct structure-activity correlations of the parent compound were elucidated based on these derivatives. PMID:26992112

  12. Are combined AOPs effective for toxicity reduction in receiving marine environment? Suitability of battery of bioassays for wastewater treatment plant (WWTP) effluent as an ecotoxicological assessment.

    Science.gov (United States)

    Díaz-Garduño, B; Rueda-Márquez, J J; Manzano, M A; Garrido-Pérez, C; Martín-Díaz, M L

    2016-03-01

    Ecotoxicological assessment of three different wastewater treatment plant (WWTP) effluents D1, D2 and D3 was performed before and after tertiary treatment using combination of advanced oxidation processes (AOPs). A multibarrier treatment (MBT) consisting of microfiltration (MF), hydrogen peroxide photolysis (H2O2/UVC) and catalytic wet peroxide oxidation (CWPO) was applied for all effluents. Sparus aurata, Paracentrotus lividus, Isochrysis galbana and Vibrio fischeri, representing different trophic levels, constituted the battery of bioassays. Different acute toxicity effects were observed in each WWTP effluents tested. The percentage of sea urchin larval development and mortality fish larvae were the most sensitive endpoints. Significant reduction (p MBT process. Base on obtained results, tested battery of bioassays in pT-method framework can be recommended for acute toxicity preliminary evaluation of WWTP effluents for the marine environment. PMID:26741736

  13. Recombinant receptor/reporter gene bioassays for assessing the estrogenic and dioxin-like activities of xenobiotics and complex mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zacharewski, T. [Univ. of Western Ontario, London, Ontario (Canada). Dept. of Pharmacology and Toxicology

    1995-12-31

    Exposure to naturally occurring or synthetic substances that possess sex steroid and/or dioxin-like activity may have long range effects on human health, reproductive fitness and environmental quality. Results from recent epidemiological studies have suggested that xenobiotics with sex steroid activity may contribute to the development of hormone-dependent cancers and disorders in the male reproductive tract as well as attenuate sperm production. However, most of these compounds, which are referred to as endocrine disruptors, are structurally dissimilar to sex steroids. Yet, based upon ambiguous assays, it has been conceded that the effects of these compounds are mediated by receptors. The authors have taken advantage of the mechanism of action of these compounds to develop recombinant receptor/reporter gene bioassays for environmental estrogens and dioxin-like compounds. The assays use an easily measurable enzyme activity (i.e. firefly luciferase), exhibit improved sensitivity and selectivity and are amenable to automation. Data will be presented demonstrating that phytoestrogens (e.g. genistein) and xenobiotics such as pesticides (e.g. DDT, Kepone), nonionic surfactants (e.g. p-nonylphenol), and precursors used in the manufacture of plastics (e.g. Bisphenol A) exhibit estrogenic activity. In addition, the assays have been used to detect estrogenic and dioxin-like activity in complex mixtures such as pulp and paper mill black liquor and effluent. These results demonstrate the utility of recombinant receptor/reporter gene bioassays for identifying substances or complex mixtures with estrogenic and/or dioxin-like activity.

  14. Zebrafish bioassay-guided microfractionation identifies anticonvulsant steroid glycosides from the Philippine medicinal plant Solanum torvum.

    Science.gov (United States)

    Challal, Soura; Buenafe, Olivia E M; Queiroz, Emerson F; Maljevic, Snezana; Marcourt, Laurence; Bock, Merle; Kloeti, Werner; Dayrit, Fabian M; Harvey, Alan L; Lerche, Holger; Esguerra, Camila V; de Witte, Peter A M; Wolfender, Jean-Luc; Crawford, Alexander D

    2014-10-15

    Medicinal plants used for the treatment of epilepsy are potentially a valuable source of novel antiepileptic small molecules. To identify anticonvulsant secondary metabolites, we performed an in vivo, zebrafish-based screen of medicinal plants used in Southeast Asia for the treatment of seizures. Solanum torvum Sw. (Solanaceae) was identified as having significant anticonvulsant activity in zebrafish larvae with seizures induced by the GABAA antagonist pentylenetetrazol (PTZ). This finding correlates well with the ethnomedical use of this plant in the Philippines, where a water decoction of S. torvum leaves is used to treat epileptic seizures. HPLC microfractionation of the bioactive crude extract, in combination with the in vivo zebrafish seizure assay, enabled the rapid localization of several bioactive compounds that were partially identified online by UHPLC-TOF-MS as steroid glycosides. Targeted isolation of the active constituents from the methanolic extract enabled the complete de novo structure identification of the six main bioactive compounds that were also present in the traditional preparation. To partially mimic the in vivo metabolism of these triterpene glycosides, their common aglycone was generated by acid hydrolysis. The isolated molecules exhibited significant anticonvulsant activity in zebrafish seizure assays. These results underscore the potential of zebrafish bioassay-guided microfractionation to rapidly identify novel bioactive small molecules of natural origin. PMID:25127088

  15. Improvement of Chemically-activated Luciferase Gene Expression Bioassay for Detection of Dioxin-like Chemicals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To improve the chemically-activated luciferase expression (CALUX)bioassay for detection of dioxin-like chemicals (DLCs) based on the toxicity mechanisms of DLCs. Method A recombinant vector was constructed and used to transfect human hepatoma (HepG2). The expression of this vector was 10-100 folds higher than that of pGL2used in previous experiments. The transfected cells showed aromatic hydrocarbon receptor (AhR)-meditated luciferase gene expression. The reliability of luciferase induction in this cell line as a reporter of AhR-mediated toxicity was evaluated, the optimal detection time was examined and a comparison was made by using the commonly used ethoxyresoufin-Odeethylase (EROD) activity induction assay. Result The results suggested that the luciferase activity in recombinant cells was peaked at about 4 h and then decreased to a stable activity by 14 h after TCDD treatment. The detection limit of this cell line was 0.1 lpmol/L, or 10-fold lower than in previous studies, with a linear range from 1 to 100pmol/L, related coefficient of 0.997, and the coefficient of variability (CV) of 15-30%,Conclusion The luciferase induction is 30-fold more sensitive than EROD induction, the detection time is 68 h shorter and the detection procedure is also simpler.

  16. Glycan heterogeneity on gold nanoparticles increases lectin discrimination capacity in label-free multiplexed bioassays.

    Science.gov (United States)

    Otten, Lucienne; Vlachou, Denise; Richards, Sarah-Jane; Gibson, Matthew I

    2016-07-21

    The development of new analytical tools as point-of-care biosensors is crucial to combat the spread of infectious diseases, especially in the context of drug-resistant organisms, or to detect biological warfare agents. Glycan/lectin interactions drive a wide range of recognition and signal transduction processes within nature and are often the first site of adhesion/recognition during infection making them appealing targets for biosensors. Glycosylated gold nanoparticles have been developed that change colour from red to blue upon interaction with carbohydrate-binding proteins and may find use as biosensors, but are limited by the inherent promiscuity of some of these interactions. Here we mimic the natural heterogeneity of cell-surface glycans by displaying mixed monolayers of glycans on the surface of gold nanoparticles. These are then used in a multiplexed, label-free bioassay to create 'barcodes' which describe the lectin based on its binding profile. The increased information content encoded by using complex mixtures of a few sugars, rather than increased numbers of different sugars makes this approach both scalable and accessible. These nanoparticles show increased lectin identification power at a range of lectin concentrations, relative to single-channel sensors. It was also found that some information about the concentration of the lectins can be extracted, all from just a simple colour change, taking this technology closer to being a realistic biosensor. PMID:27181289

  17. Comparison of solid-phase bioassays and ecoscores to evaluate the toxicity of contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Lors, Christine [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France); Centre National de Recherche sur les Sites et Sols Pollues, 930 Boulevard Lahure, BP 537, 59505 Douai Cedex (France); Ponge, Jean-Francois, E-mail: ponge@mnhn.f [Museum National d' Histoire Naturelle, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Martinez Aldaya, Maite [Museum National d' Histoire Naturelle, CNRS UMR 7179, 4 Avenue du Petit-Chateau, 91800 Brunoy (France); Damidot, Denis [Universite Lille Nord de France, 1bis rue Georges Lefevre, 59044 Lille Cedex (France); Ecole des Mines de Douai, MPE-GCE, 941 rue Charles-Bourseul, 59500 Douai (France)

    2010-08-15

    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. - The avoidance test using the soil springtail Folsomia candida is globally more sensitive to PAH contamination than acute and chronic toxicity bioassays using plants and animals but a battery of tests could reveal better in detail.

  18. Development and validation of microbial bioassay for quantification of Levofloxacin in pharmaceutical preparations

    Institute of Scientific and Technical Information of China (English)

    Nishant A. Dafale; Uttam P. Semwal; Piyush K. Agarwal; Pradeep Sharma; G.N. Singh

    2015-01-01

    The aim of this study was to develop and validate a simple, sensitive, precise and cost-effective one-level agar diffusion (5þ1) bioassay for estimation of potency and bioactivity of Levofloxacin in pharmaceutical preparation which has not yet been reported in any pharmacopoeia. Among 16 microbial strains, Bacillus pumilus ATCC-14884 was selected as the most significant strain against Levofloxacin. Bioassay was optimized by investigating several factors such as buffer pH, inoculums concentration and reference standard concentration. Identification of Levofloxacin in commercial sample Levoflox tablet was done by FTIR spectroscopy. Mean potency recovery value for Levofloxacin in Levoflox tablet was estimated as 100.90%. A validated bioassay method showed linearity (r2 ¼ 0.988), precision (Interday RSD ¼ 1.05%, between analyst RSD ¼ 1.02%) and accuracy (101.23%, RSD ¼ 0.72%). Bioassay was correlated with HPLC using same sample and estimated potencies were 100.90%and 99.37%, respectively. Results show that bioassay is a suitable method for estimation of potency and bioactivity of Levofloxacin pharmaceutical preparations.

  19. Selecting a sensitive battery of bioassays to detect toxic effects of metals in effluents.

    Science.gov (United States)

    de Paiva Magalhães, Danielly; da Costa Marques, Mônica Regina; Fernandes Baptista, Darcilio; Forsin Buss, Daniel

    2014-09-01

    The use of bioassay batteries is necessary to evaluate toxic effects at various biological levels. The selection of bioassays without prior testing and determination of the most sensitive/suitable groups for each impact may allow the discharge of effluents that pose a threat to the environment. The present study tested and selected a battery of sensitive ecotoxicological bioassays for detecting toxic effects of metals. The sensitivities of six organisms were evaluated (algae Pseudokirchneriella subcapitata and Chlorella vulgaris, Cladocera Daphnia similis and Ceriodaphnia dubia, and fish Poecilia reticulata and Danio rerio) after exposure to 10 individual metal species deemed toxic to the aquatic environment (Ag(+), Cd(2+), Cu(+), Cu(2+), Cr(3+), Cr(6+), Pb(2+), Ni(2+), Zn(2+), and Hg(2+)) and to real (steel-mill) and laboratory simulated effluents. In the bioassays, fish were the least sensitive; D. rerio showed no sensitivity to any of the effluents tested. P. subcapitata was a good bioindicator of Cr(3+) toxicity, and D. similis was the most sensitive organism to Hg(2+); but the toxic effect of effluents with higher levels of Hg(2+) was better detected by C. dubia. The most sensitive battery of bioassays to detect low concentrations of dissolved metals in effluents was the 72-h chronic test with C. vulgaris and the 48-h acute test with C. dubia. PMID:25199585

  20. Implementation of bioassay methods to improve assessment of incorporated radionuclides

    International Nuclear Information System (INIS)

    Full text: Internal exposure to uranium and thorium can principally be assessed from external radiation measurements, exhalation measurements, or the assay of these elements excreted in urine or feces. Since both 232Th and 238U emit only photon radiations of low energy and with low emission probabilities, their detection limits by in vivo counting are of the order of kBq even when sophisticated devices are used. Consequently, usually bioassay methods are used for the incorporation monitoring of workers. Alpha spectrometry is the commonly applied technique, usually employed to measure 232Th and 238U in urine or fecel samples. For accurate analysis of body contents, 24 hours collections of urine or feces are usually used. The fecal activity, however, resembles predominantly the intake by ingestion of these nuclides during the last few days whereas the urinary excretion is more closely related to the body content of the nuclides. However, urinary excretion is also varying with the actual intake of 232Th and/or 238U. The measurement of these nuclides in urine by alpha-spectrometry requires tedious and time-consuming chemical work-up to prepare the samples for spectrometric analysis. Therefore, the number of analyses, which can be carried out is quite low and the results are available only after a time lag of several days. Additionally, under certain conditions the alpha-spectrometry is not sensitive enough. Other methods that have been developed may be confined to the availability of certain devices being difficult to access (e.g. nuclear reactors for radiochemical neutron activation analysis). Much better suitable as routine method is the application of inductively coupled plasma mass spectrometry (ICP-MS) for measurements of 232Th and 238U concentrations in urine. For elemental analyses, ICP-MS can already be considered as commonly used method. The present work which was carried out in the framework of an EU project (IDEA: Internal Dosimetry - Enhancements in

  1. Toxicity Assessment of Sediments with Natural Anomalous Concentrations in Heavy Metals by the Use of Bioassay

    Directory of Open Access Journals (Sweden)

    Francisco Martín

    2010-01-01

    Full Text Available The potential toxicity in riverbed sediments was assessed with a bioassay using the bioluminescent bacteria Vibrio fischeri. The selected area was characterized by the presence of ultramafic rocks (peridotites, and the sediments had high values in Ni, Cr, and Co. For the toxicity bioassay with Vibrio fischeri, water-soluble forms were used. The results indicated that most of the samples had a very low degree of toxicity, with 10% of reduction in luminescence in relation to the control; meanwhile 25% of the samples had a moderate degree of toxicity with a reduction in luminescence between 13 and 21% in relation to the control. The toxicity index correlated significantly with the concentrations of Ni and Cr in the water extracts. This toxicity bioassay was proved to be a sensitive and useful tool to detect potential toxicity in solutions, even with anomalous concentrations in heavy metals of natural origin.

  2. Current status of bioassay procedures to detect and quantify previous exposures to radioactive materials

    International Nuclear Information System (INIS)

    This paper was prepared by a working group established by the Oak Ridge Associated Universities (ORAU) for the purpose of assessing the current capabilities of bioassay methods that can be used to determine the occurrence and magnitude of a previous internal deposition of one or more radionuclides. The first five sections discuss general features of the use of in-vitro bioassay samples to achieve this purpose. The remainder of the paper is focused on the possible use of urine bioassay procedures to detect and quantify internal depositions of radionuclides that may have occurred in United States occupation troops in Hiroshima or Nagasaki, Japan, prior to 1 July 1946, or to personnel who participated in atmospheric nuclear weapons tests conducted between 1945 and 1962. Theoretical calculations were made to estimate the quantities of various radionuclides produced in a 20-kiloton (kt) nuclear detonation that might still be present in measurable quantities in people today if they were exposed 25 to 40 y ago

  3. A Brine Shrimp Bioassay for Measuring Toxicity and Remediation of Chemicals

    Science.gov (United States)

    Lieberman, Marya

    1999-12-01

    A bioassay using Artemia franciscana (brine shrimp) was adapted to measure the toxicity of household chemicals. One project is described in which students collect dose-response curves for seven commercial flea-killing products. Next, groups of students researched the insecticidal ingredients of the flea products. On the basis of the structures of the active ingredients, they chose remediation methods to make the flea product less toxic to brine shrimp; procedures included copper-catalyzed hydrolysis, adsorption onto activated charcoal, bleach treatment, and photodegradation. No special equipment or supplies are necessary for the bioassay other than the brine shrimp eggs, which can be obtained at any aquarium store.

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

    Energy Technology Data Exchange (ETDEWEB)

    CGCampbell@lbl.gov

    2004-01-30

    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.

  5. Interlaboratory comparisons of receptor binding assay with mouse bioassay as screening method for shellfish toxicity

    International Nuclear Information System (INIS)

    The Receptor-binding Assay (RBA) is an isotope-based technique using tritium-labeled saxitoxin (STX) as a tracer. Its response is based on the competition between the labeled and unlabeled saxitoxin to specifically interact with its receptor, sodium (Na+) channel. RBA is locally established at PNRI and now being routinely used for research purposes. RBA results were compared with the standard mouse bioassay method (MBA) as a part of screening program for shellfish toxins. The Microplate RBA is shown to have a sensitivity of 0.40 μg Saxitoxin equiv/100 g shellfish meat. A good agreement at low levels (40-50 μg Saxitoxin equiv/100 g shellfish meat) in the preliminary assays was obtained between the methods. With this, RBA method shows potential in the routine monitoring of shellfish PSP toxicity. Assay interlaboratory comparisons among Asia-Pacific Region laboratories were also performed. The RBA, in microplate and traditional formats, shown to have a sensitivity of 0.30 and 0.25 μg STX equiv/100 g shellfish meat respectively. The inter-and intra-assay variation for RBA is within 5-11%, which met the <30% criterion. The quality control check is within 6.3%, which validates day-to-day analyses. The results are highly comparable and consistent with expected values, with an RSD value <20%, as expected for good variability among the samples. RBA results were highly correlated and exhibited close quantitative agreement with MBA. It provides a reliable means of rapidly assessing PSP toxicity in laboratory and field samples. Thus, RBA can be effective screening tool in responding to suspected cases of PSP intoxication. (author)

  6. Beoordeling van gereinigde grond. V. Toepassing van bioassays met planten en regenwormen op verontreinigde en gereinigde gronden

    NARCIS (Netherlands)

    van Gestel CAM; Dirven-van Breemen EM; Kamerman JW

    1992-01-01

    Within the framework of the project "Evaluation of decontaminated soil", the applicability of bioassays with earthworms and plants for the quality assessment of decontaminated soil is investigated. In the final phase of this project, bioassays with earthworms and plants (radish, lettuce)

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

    Science.gov (United States)

    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. PMID:26971814

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

    Science.gov (United States)

    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. PMID:20359802

  9. Complete Genome Sequence of Cyanobium sp. NIES-981, a Marine Strain Potentially Useful for Ecotoxicological Bioassays

    Science.gov (United States)

    Shimura, Yohei; Suzuki, Shigekatsu; Yamagishi, Takahiro; Tatarazako, Norihisa; Kawachi, Masanobu

    2016-01-01

    Cyanobium sp. NIES-981 is a marine cyanobacterium isolated from tidal flat sands in Okinawa, Japan. Here, we report the complete 3.0-Mbp genome sequence of NIES-981, which is composed of a single chromosome, and its annotation. This sequence information may provide a basis for developing an ecotoxicological bioassay using this strain. PMID:27469961

  10. Applicability of a yeast bioassay in the detection of steroid esters in hair

    NARCIS (Netherlands)

    Becue, I.; Bovee, T.F.H.; Poucke, C.; Groot, M.J.; Nielen, M.W.F.; Peteghem, van C.

    2011-01-01

    The aim of the present study was to demonstrate the applicability of a yeast androgen and estrogen bioassay in the detection of steroid esters in hair samples of animals treated with a hormone ester cocktail. The outcome of the activity screenings was critically compared with the results previously

  11. Determination of Biochemical Oxygen Demand of Area Waters: A Bioassay Procedure for Environmental Monitoring

    Science.gov (United States)

    Riehl, Matthew

    2012-01-01

    A graphical method for determining the 5-day biochemical oxygen demand (BOD5) for a body of water is described. In this bioassay, students collect a sample of water from a designated site, transport it to the laboratory, and evaluate the amount of oxygen consumed by naturally occurring bacteria during a 5-day incubation period. An accuracy check,…

  12. Determining UV Inactivation of Toxoplasma gondii Oocysts by Using Cell Culture and a Mouse Bioassay

    Science.gov (United States)

    The effect of UV exposure on Toxoplasma gondii oocysts has not been completely defined for use in water disinfection. This study evaluated UV irradiated oocysts by three assays: a SCID mouse bioassay, an in vitro T. gondii oocyst plaque assay (TOP-assay), and a quantitative reve...

  13. Evaluation of soil bioassays for use at Washington state hazardous waste sites: A pilot study

    International Nuclear Information System (INIS)

    The Washington State Department of Ecology (Ecology) is developing guidelines to assess soil toxicity at hazardous waste sites being investigated under the Washington Model Toxics Control Act Cleanup Regulation. To evaluate soil toxicity, Ecology selected five bioassay protocols -- Daphnia, Earthworm, Seedling, Fathead Minnow, and Frog Embryo Teratogenesis Assay Xenopus (FETAX) -- for use as screening level assessment tools at six State hazardous waste sites. Sites contained a variety of contaminants including metals, creosote, pesticides, and petroleum products (leaking underground storage tanks). Three locations, representing high, medium, and low levels of contamination, were samples at each site. In general, the high contaminant samples resulted in the highest toxic response in all bioassays. The order of site toxicity, as assessed by overall toxic response, is creosote, petroleum products, metals, and pesticides. Results indicate that human health standards, especially for metals, may not adequately protect some of the species tested. The FETAX bioassay had the greatest overall number of toxic responses and lowest variance. The seedling and Daphnia bioassays had lower and similar overall toxic response results, followed by the earthworm and fathead minnow. Variability was markedly highest for the seedling. The Daphnia and fathead minnow variability were similar to the FETAX level, while the earthworm variability was slightly higher

  14. Age and sex related responsiveness of Tribolium castaneum (Coleoptera: Tenebrionidae) in novel behavioral bioassays

    Science.gov (United States)

    The hardiness and mobile nature of Tribolium castaneum (Herbst) make them easy to work with but are the same factors that make their responses to behavior modifying chemical stimuli difficult to evaluate. To overcome these difficulties we developed two bioassays: a two choice test with airflow and a...

  15. Using a Macroalgal δ15N Bioassay to Detect Cruise Ship Waste Water Effluent Inputs

    Science.gov (United States)

    Nitrogen stable isotopes are a powerful tool for tracking sources of N to marine ecosystems. I used green macroalgae as a bioassay organism to evaluate if the δ15N signature of cruise ship waste water effluent (CSWWE) could be detected in Skagway Harbor, AK. Opportunistic green...

  16. The Intersection of CMOS Microsystems and Upconversion Nanoparticles for Luminescence Bioimaging and Bioassays

    Directory of Open Access Journals (Sweden)

    Liping Wei

    2014-09-01

    Full Text Available 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.

  17. Development of bioassay techniques with extracts from semi-permeable membrane devices (SPMDs)

    Energy Technology Data Exchange (ETDEWEB)

    Metcalfe, T.L.; White, P.; Mackay, D.; Metcalfe, C. [Trent Univ., Peterborough, Ontario (Canada). Environmental and Resource Studies Program

    1995-12-31

    Semi-permeable membrane devices (SPMDs), consisting of polyethylene bags filled with triolein, have been used to monitor for lipophilic organic contaminants in water. Although extracts from SPMDs have most often been analyzed for concentrations of organic contaminants, there is also the potential to monitor the toxicity of these extracts using in vitro and in vivo bioassays. SPMDs were deployed for four weeks at several sites along a corridor extending from Peche Island in the Detroit River to Pelee Island in western Lake Erie to monitor the distribution of toxic organic contaminants in the water. Analysis of the extracts from the SPMDs for concentrations of PCBs and other organochlorine compounds, and polynuclear aromatic hydrocarbons (PAHs) indicated that the regions in the Detroit River within the Trenton Channel and near Zug Island were the most highly contaminated. Bioassays conducted with extracts from the SPMDs included the in vitro SOS Chromotest for genotoxic activity, an acute lethality test with Daphnia magna, and a fish embryotoxicity test with embryos of Japanese medaka (Oryzias latipes). These bioassay data generally indicated that the toxicity and concentrations of organic contaminants in the SPMD extracts were correlated. This study indicates that there is potential to use short-term bioassays of extracts from SPMDs to monitor for in situ contamination in the aquatic environment.

  18. An Estuarine Fish Bioassay for Sensitive Biomonitoring of Oil-related Contamination

    Science.gov (United States)

    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 ...

  19. Occupational monitoring programme of uranium concentrate unit in Caetite, Brazil: Bioassay programme

    International Nuclear Information System (INIS)

    Full text: The principal aim of the bioassay monitoring program in the Uranium Concentrate Unity in Caetite is the maintenance of acceptable safe and satisfactory working conditions, according to national and international norms. Specifically, the objective is to interpret measurements in terms of intake of uranium and committed effective dose, so that the results can be used to demonstrate compliance with the system of dose limitation and, mainly, the optimization of radiation protection. The employed technique is the measurement of uranium in excreta from workers in mine, crushing and uranium concentrate production areas. The present work also aims at reporting the analysis results of incorporation of natural uranium, from bio analyses of urine on routine for class y insoluble uranium (ore dust) and operational monitoring for class D solubility uranium (Ammonium Diuranate), and committed effective dose estimates of workers occupationally exposed. In conclusion, workers from the mining and crushing areas should be monitored by the routine program; urine and feces samples should be analysed by mass spectrometry, with ICPMS. The operational monitoring program should be carried out in workers from the uranium concentrate production area; urine and feces samples may be analysed by less expensive techniques. For routine monitoring, based on the Mann-whitney Test, data from baseline monitoring were considered statistically equal to data from routine monitoring. Only three of out 24 workers showed results higher than the baseline, generating calculation of committed effective dose. However, none of them reached values bigger than those allowed to workers in Brazilian regulations. For operational monitoring the same behavior described above is repeated, with baseline data considered statistically equal to operational monitoring, and only three out of 18 workers showed higher values in the operational monitoring. Once again values were within the limits established in

  20. Screening for unicellular algae as possible bioassay organisms for monitoring marine water samples.

    Science.gov (United States)

    Millán de Kuhn, Rosmary; Streb, Christine; Breiter, Roman; Richter, Peter; Neesse, Thomas; Häder, Donat-Peter

    2006-08-01

    ECOTOX is an automatic early warning system to monitor potential pollution of freshwater, municipal or industrial waste waters or aquatic ecosystems. It is based on a real time image analysis of the motility and orientation parameters of the unicellular, photosynthetic flagellate Euglena gracilis. In order to widen the use of the device to marine habitats and saline waters nine marine flagellates were evaluated as putative bioassay organisms, viz. Dunaliella salina, Dunaliella viridis, Dunaliella bardawil, Prorocentrum minimum Kattegat, P. minimum Lissabon, Tetraselmis suecica, Heterocapsa triquetra, Gyrodinium dorsum and Cryptomonas maculata. Because of their slow growth the last three strains were excluded from further evaluation. Selection criteria were ease of culture, density of cell suspension, stability of motility and gravitactic orientation. The sensitivity toward toxins was tested using copper(II) ions. The instrument allows the user to automatically determine effect-concentration (EC) curves from which the EC(50) values can be calculated. For the interpretation of the EC curves a sigmoid logistic model was proposed which proved to be satisfactory for all tested strains. The inhibition of the motility was considered as the most appropriate movement parameter as an endpoint. The Dunaliella species had the lowest sensitivity to copper with EC(50) values of 220, 198 and 176 mg/L for D. salina, D. bardawil and D. viridis, respectively, followed by T. suecica with an EC(50) value of 40 mg/L. The Prorocentrum species were found to be the most sensitive with an EC(50) value of 13.5 mg/L for P. minimum Lissabon and 7.5 mg/L for P. minimum Kattegat. PMID:16806394

  1. Regional differences in stratum corneum reactivity to surfactants. Quantitative assessment using the corneosurfametry bioassay.

    Science.gov (United States)

    Henry, F; Goffin, V; Maibach, H I; Piérard, G E

    1997-12-01

    The skin does not react similarly to the presence of xenobiotics over all anatomic sites. Distinct regional differences have been described for irritancy and percutaneous absorption. The present study assesses the regional variation of stratum corneum reactivity to surfactants using the corneosurfametry bioassay. Stratum corneum was harvested from 6 body sites in 20 young adults. Corneosurfametry was performed using water, 1% SLS and a 5% soap solution. Data show that the best variable to assess regional variability in irritancy is the overall difference in corneosurfametry (ODC), comparing the effect of a given surfactant with water. The dorsal hand and volar forearm were the least reactive, the neck, forehead, back and dorsal foot the most reactive, sites. It is concluded that the corneosurfametry bioassay, through the ODC variable, is a practically noninvasive tool for the evaluation of regional variation in irritancy at the level of the stratum corneum.

  2. Trace analysis of ecdysones by gas--liquid chromatography, radioimmunoassay, and bioassay

    International Nuclear Information System (INIS)

    A radioimmunoassay was compared to a gas-liquid chromatographic assay and a bioassay as a method for quantifying ecdysone titers in arthropods. In addition a continuous-development thin layer chromatographic technique was evaluated as a means for separating various ecdysone analogues. The carboxymethoxyamine derivative of β-ecdysone was synthesized and characterized by several spectral methods. This derivative was conjugated to bovine serum albumin to afford a suitable antigen and injected into rabbits. The antisera produced shows a moderate affinity for β-ecdysone and cross-reacts with many ecdysone analogues. Ecdysones were also quantified directly as trimethylsilyl ethers using a 63Ni electron capture detector in a gas-liquid chromatographic system. Less than 50 pg of material could be detected per injection. Both of these techniques and the Musca domestica bioassay were used for the comparative analysis of a number of biological samples. The advantages and disadvantages of the various methods are discussed. (U.S.)

  3. Compost maturity assessment using physicochemical, solid-state spectroscopy, and plant bioassay analysis.

    Science.gov (United States)

    Kumar, D Senthil; Kumar, P Satheesh; Rajendran, N M; Anbuganapathi, G

    2013-11-27

    The vermicompost produced from flower waste inoculated with biofertilizers was subjected to compost maturity test: (i) physicochemical method (pH, OC, TN, C:N); (ii) solid state spectroscopic analysis (FTIR and (13)C CPMAS NMR); and (iii) plant bioassay (germination index). The pH of vermicompost was decreased toward neutral, C:N ratio vermicomposts result shows reduction of complex organic materials into simple minerals which indicates the maturity of the experimental vermicompost product than the control. The increased aliphatic portion incorporated with flower residues may be due to the synthesis of alkyl, O-alkyl, and COO groups by the microbes present in the gut of earthworm. Plant bioassays are considered the most conventional assessment of compost maturity analysis, and subsequently, it shows the effect of vermicompost maturity on the germination index of Vigna mungo . PMID:24191667

  4. Toxicity assays in nanodrops combining bioassay and morphometric endpoints.

    OpenAIRE

    Lemaire, Frédéric; Mandon, Céline A; Reboud, Julien; Papine, Alexandre; Angulo, Jesus; Pointu, Hervé; Diaz-Latoud, Chantal; Lajaunie, Christian; Chatelain, François; Arrigo, André-Patrick; Schaack, Béatrice

    2007-01-01

    BACKGROUND: Improved chemical hazard management such as REACH policy objective as well as drug ADMETOX prediction, while limiting the extent of animal testing, requires the development of increasingly high throughput as well as highly pertinent in vitro toxicity assays. METHODOLOGY: This report describes a new in vitro method for toxicity testing, combining cell-based assays in nanodrop Cell-on-Chip format with the use of a genetically engineered stress sensitive hepatic cell line. We tested ...

  5. Toxicity assays in nanodrops combining bioassay and morphometric endpoints.

    Directory of Open Access Journals (Sweden)

    Frédéric Lemaire

    Full Text Available BACKGROUND: Improved chemical hazard management such as REACH policy objective as well as drug ADMETOX prediction, while limiting the extent of animal testing, requires the development of increasingly high throughput as well as highly pertinent in vitro toxicity assays. METHODOLOGY: This report describes a new in vitro method for toxicity testing, combining cell-based assays in nanodrop Cell-on-Chip format with the use of a genetically engineered stress sensitive hepatic cell line. We tested the behavior of a stress inducible fluorescent HepG2 model in which Heat Shock Protein promoters controlled Enhanced-Green Fluorescent Protein expression upon exposure to Cadmium Chloride (CdCl2, Sodium Arsenate (NaAsO2 and Paraquat. In agreement with previous studies based on a micro-well format, we could observe a chemical-specific response, identified through differences in dynamics and amplitude. We especially determined IC50 values for CdCl2 and NaAsO2, in agreement with published data. Individual cell identification via image-based screening allowed us to perform multiparametric analyses. CONCLUSIONS: Using pre/sub lethal cell stress instead of cell mortality, we highlighted the high significance and the superior sensitivity of both stress promoter activation reporting and cell morphology parameters in measuring the cell response to a toxicant. These results demonstrate the first generation of high-throughput and high-content assays, capable of assessing chemical hazards in vitro within the REACH policy framework.

  6. Recombinant Streptomyces clavuligerus strain including cas2 gene production and analysis its antibiotic overproduction by bioassay

    Directory of Open Access Journals (Sweden)

    Zohreh Hojati

    2014-03-01

    Full Text Available Background: Streptomyces clavuligerus is one of the most important strain that produce clavulanic acid that wildly used in combination of strong but sensitive to β-lactamase antibiotics in clinics. The cas2 is one of the important genes in the biosynthesis pathway of clavulanic acid. Materials and Methods: The recombinant construct pMTcas2 which contain cas2 gene is obtained from Isfahan University. Recombinant plasmid extracts from streptomyces lividans and confirm by enzyme digestion. The streptomyces clavuligerus protoplast was prepared and transformation was done by using polyethylene glycol. Transformation was confirmed by plasmid extraction and PCR using cas2 specific primers. Finally, bioassay method was used to survey the effect of extra copy of cas2 on clavulanic acid production. Result: Plasmid extraction was initially carried out and the structure of plasmid was confirmed by digestion. The typical white colony was seen on protoplast recovery culture containing thiostrepton antibiotic and gray spores were detected after one week. Plasmid extraction was done from transformed strain and transformation was confirmed by PCR. The results of the bioassay show that amplification of the cas2 gene in multicopy plasmids resulted in a 4.1 fold increase in clavulanic acid production. Conclusion: The bioassay was done and the diameters of zone of inhibition in control and sample were compared. The results of the bioassay show that amplification of the cas2 gene in multicopy plasmids resulted in a 4.1 fold increase in clavulanic acid production. Overproduction of clavulanic acid decreases the cost of its dependent drug production.

  7. Carcinogenic risk of copper gluconate evaluated by a rat medium-term liver carcinogenicity bioassay protocol

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Masayoshi; Usuda, Koji; Hayashi, Seigo; Ogawa, Izumi; Furukawa, Satoshi [Nissan Chemical Industries Limited, Toxicology and Environmental Science Department, Biological Research Laboratories, Saitama (Japan); Igarashi, Maki [Tokyo University of Agriculture, Laboratory of Protection of Body Function, Department of Food and Nutritional Science, Graduate School of Agriculture, Tokyo (Japan); Nakae, Dai [Tokyo University of Agriculture, Laboratory of Protection of Body Function, Department of Food and Nutritional Science, Graduate School of Agriculture, Tokyo (Japan); Tokyo Metropolitan Institute of Public Health, Tokyo (Japan)

    2008-08-15

    Carcinogenic risk and molecular mechanisms underlying the liver tumor-promoting activity of copper gluconate, an additive of functional foods, were investigated using a rat medium-term liver carcinogenicity bioassay protocol (Ito test) and a 2-week short-term administration experiment. In the medium-term liver bioassay, Fischer 344 male rats were given a single i.p. injection of N-nitrosodiethylamine at a dose of 200 mg/kg b.w. as a carcinogenic initiator. Starting 2 weeks thereafter, rats received 0, 10, 300 or 6,000 ppm of copper gluconate in diet for 6 weeks. All rats underwent 2/3 partial hepatectomy at the end of week 3, and all surviving rats were killed at the end of week 8. In the short-term experiment, rats were given 0, 10, 300 or 6,000 ppm of copper gluconate for 2 weeks. Numbers of glutathione S-transferase placental form (GST-P) positive lesions, single GST-P-positive hepatocytes and 8-oxoguanine-positive hepatocytes, and levels of cell proliferation and apoptosis in the liver were significantly increased by 6,000 ppm of copper gluconate in the medium-term liver bioassay. Furthermore, hepatic mRNA expression of genes relating to the metal metabolism, inflammation and apoptosis were elevated by 6,000 ppm of copper gluconate both in the medium-term liver bioassay and the short-term experiments. These results indicate that copper gluconate possesses carcinogenic risk toward the liver at the high dose level, and that oxidative stress and inflammatory and pro-apoptotic signaling statuses may participate in its underlying mechanisms. (orig.)

  8. Bioassay-Directed Isolation of Active Compounds with Antiyeast Activity from a Cassia fistula Seed Extract

    OpenAIRE

    Subramanion L. Jothy; Sreenivasan Sasidharan; Lai Ngit Shin; Lachimanan Yoga Latha; Yee Ling Lau; Yeng Chen; Zuraini Zakaria

    2011-01-01

    Background and objective: Cassia fistula L belongs to the family Leguminosae, and it is one of the most popular herbal products in tropical countries. C. fistula seeds have been used as a herbal medicine and have pharmacological activity which includes anti-bacterial, anti-fungal, and antioxidant properties. The goal of this study was to identify compounds from C. fistula seeds which are responsible for anti-Candida albicans activity using bioassay-directed isolation. Results: The preliminary...

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

    Science.gov (United States)

    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. PMID:27312898

  10. Bioassay for grooming effectiveness towards Varroa destructor mites in Africanized and Carniolan honey bees

    OpenAIRE

    Aumeier, Pia

    2001-01-01

    International audience Grooming behavior is considered a varroosis tolerance factor of Africanized honey bees, but this behavior is difficult to evaluate directly within the honey bee colony. A laboratory bioassay was developed to measure the intensity and effectiveness of grooming responses by worker bees artificially infested with one Varroa mite. At a study site in tropical Brazil, the sequence of seven well- defined grooming reactions towards mites of different colonial origin was comp...

  11. Bioassays Against Pinewood Nematode: Assessment of a Suitable Dilution Agent and Screening for Bioactive Essential Oils

    OpenAIRE

    Ana Cristina Figueiredo; Luis G. Pedro; Barroso, José G.; Maria Teresa Tinoco; Luís Silva Dias; Mendes, Marta D.; Jorge M. S. Faria; Pedro Barbosa; Manuel Mota

    2012-01-01

    Acetone was investigated and found to be an appropriate alternative to Triton X-100 as a solvent of essential oils in bioassays aimed to investigate their effects on pinewood nematode (Bursaphelenchus xylophilus) mortality. Therefore it was used as dilution agent to screen the effectiveness of fifty two essential oils against this pest. Thirteen essential oils were highly effective, resulting in more than 90% pinewood nematode mortality at 2 mg/mL, with six of them resulting in 100% mortality...

  12. Biological screening of selected Pacific Northwest forest plants using the brine shrimp (Artemia salina) toxicity bioassay.

    Science.gov (United States)

    Karchesy, Yvette M; Kelsey, Rick G; Constantine, George; Karchesy, Joseph J

    2016-01-01

    The brine shrimp (Artemia salina) bioassay was used to screen 211 methanol extracts from 128 species of Pacific Northwest plants in search of general cytotoxic activity. Strong toxicity (LC50  1000 µg/ml). Our subsequent studies of conifer heartwoods with strong activity confirm the assay's value for identifying new investigational leads for materials with insecticidal and fungicidal activity. PMID:27186474

  13. Toxicity Assessment of Perchloroethylene and Intermediate Products after Advanced Oxidation Process by Daphnia Magna Bioassay

    OpenAIRE

    Mahdi Kargar; Kazem Naddafi; Ramin Nabizadeh

    2014-01-01

    Background and objective: Perchloroethylene is a chlorinated hydrocarbon used as a solvent in many industries and services activities such as dry cleaning and auto industry as degreasing. We carried out a bioassay using Daphnia Magna in order to determine the ecological effects of wastewater treatment through applying advanced oxidation processes (ultrasonic, ultraviolet irradiation and hydrogen peroxide processes) for removal of perchloroethylene. Materials and Methods: Due to the sensiti...

  14. Predictions for the outcome of rodent carcinogenicity bioassays: identification of trans-species carcinogens and noncarcinogens.

    OpenAIRE

    Tennant, R W; Spalding, J.

    1996-01-01

    Thirty chemicals or substances currently undergoing long-term carcinogenicity bioassays in rodents have been used in a project to further evaluate methods and information that may have the capability of predicting potential carcinogens. In our predictions the principal information used includes structural alerts and in vitro test results for Salmonella mutagenicity, relative subchronic toxicity, and the sites and types of pathology found in subchronic (90-day) studies. This group of chemicals...

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

    OpenAIRE

    Claudia Scherr; Meinhard Simon; Jörg Spranger; Stephan Baumgartner

    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 o...

  16. Bioassay- and liquid chromatography/mass spectrometry-guided acetylcholinesterase inhibitors from Picriafel-terrae

    Directory of Open Access Journals (Sweden)

    Lu Wen

    2013-01-01

    Full Text Available Background: Picria fel-terrae is a traditional Chinese medicine. Materials and Methods: A new approach to the search for acetylcholinesterase (AChE inhibitors from Picria fel-terrae is presented. Results: Bioassay- and LC-MS-guided fractionation of the ethyl acetate extract was from traditional Chinese medicine P.fel-terrae. Following primary extraction, the ethyl acetate extracts fraction of P.fel-terrae showed strong AChE inhibitory activities. So the sample was separated using highperformance liquid chromatography (HPLC. The effluent was split towards two identical 96-well fraction collectors, and the presence of the biologically interesting portion and chromatographic fractions could be readily detected by analyzing selected ion chromatograms through an electrophoresis-electrospray ionization mass spectrometry (ESIMS system for accurate mass measurement. One 96-well plate was used for a bioassay (AChE-inhibitory assay and detected the bioactivity and position of the relevant peak in the chromatogram. The positive well in the second 96-well plate was used for identification by LC-(+ ESIMS. Conclusion: As abovementioned, the AChE inhibitory constituents from P.fel-terrae by LC-bioassay-ESIMS were rapid identified. Liquid chromatography/ mass spectrometry (LC-MS screening detected the presence of six active compounds, identified as picfeltarraenin IA (1, picfeltarraenin IB (2, picfeltarraenin IV (3, picfeltarraenin X (4, picfeltarraenin XI (5, and one unknown compound. The structures were further determined by 13C NMR. The six compounds expressed stronger AChE inhibition than the known AChE inhibitorTacrine. Above all, the value of this LC-bioassay-ESIMS methodology is highlighted by the finding and structure elucidation of the active constituents from many other structural families of natural products.

  17. In Vitro Androgen Bioassays as a Detection Method for Designer Androgens

    OpenAIRE

    Heather, Alison K.; Cooper, Elliot R.; McGrath, Kristine C. Y.

    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 sup...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-12-15

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

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

    Science.gov (United States)

    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.

  20. Glycomics Approaches for the Bioassay and Structural Analysis of Heparin/Heparan Sulphates

    Directory of Open Access Journals (Sweden)

    Jeremy E. Turnbull

    2012-11-01

    Full Text Available The glycosaminoglycan heparan sulphate (HS has a heterogeneous structure; evidence shows that specific structures may be responsible for specific functions in biological processes such as blood coagulation and regulation of growth factor signalling. This review summarises the different experimental tools and methods developed to provide more rapid methods for studying the structure and functions of HS. Rapid and sensitive methods for the facile purification of HS, from tissue and cell sources are reviewed. Data sets for the structural analysis are often complex and include multiple sample sets, therefore different software and tools have been developed for the analysis of different HS data sets. These can be readily applied to chromatographic data sets for the simplification of data (e.g., charge separation using strong anion exchange chromatography and from size separation using gel filtration techniques. Finally, following the sequencing of the human genome, research has rapidly advanced with the introduction of high throughput technologies to carry out simultaneous analyses of many samples. Microarrays to study macromolecular interactions (including glycan arrays have paved the way for bioassay technologies which utilize cell arrays to study the effects of multiple macromolecules on cells. Glycan bioassay technologies are described in which immobilisation techniques for saccharides are exploited to develop a platform to probe cell responses such as signalling pathway activation. This review aims at reviewing available techniques and tools for the purification, analysis and bioassay of HS saccharides in biological systems using “glycomics” approaches.

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

    Science.gov (United States)

    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. PMID:27472199

  2. Eliminating bias in routine bioassay when there is unknown time of intake

    Energy Technology Data Exchange (ETDEWEB)

    Strom, Daniel J.

    2003-09-22

    Routine bioassay programs sometimes find evidence of an unsuspected intake. If there were no workplace indicators of exposure or intake, it is necessary to assume a value for the time of intake. Under these circumstances, the International Commission on Radiological Protection (ICRP) continues to recommend using the midpoint of the interval between routine bioassay measurements (ICRP Pub. 78, para. 106). The assumption of T/2 as the time of intake, where T is the interval between bioassay measurements, represents the expectation value of the time of intake, , assuming uniform probability of an intake at any given time. In virtually all cases presented here, this assumption results in a significant underestimation, in many cases by a factor of 2 or 3, of the expectation value of the intake, , that would have been received by a population of workers who had uniform probability over time of intake. This underestimation leads to a negative bias in dose estimates derived in this fashion. The bias is characterized for realistic, routine urinalysis programs for Pu, U, and 3H, as well as for in vivo measurements of 125I and 137Cs. Simple methods are presented for finding t, the time of using software such as IMBA, LUDEP, or CINDY. Since the primary concern is estimating intake rather than time, the assumed time of intake should be chosen as t rather than . The ICRP should consider revising some of the tables in its Publication 78 to reflect this.

  3. Bioassays as a tool for evaluating advanced oxidation processes in water and wastewater treatment.

    Science.gov (United States)

    Rizzo, Luigi

    2011-10-01

    Advanced oxidation processes (AOPs) have been widely used in water and wastewater treatment for the removal of organic and inorganic contaminants as well as to improve biodegradability of industrial wastewater. Unfortunately, the partial oxidation of organic contaminants may result in the formation of intermediates more toxic than parent compounds. In order to avoid this drawback, AOPs are expected to be carefully operated and monitored, and toxicity tests have been used to evaluate whether effluent detoxification takes place. In the present work, the effect of AOPs on the toxicity of aqueous solutions of different classes of contaminants as well as actual aqueous matrices are critically reviewed. The dualism toxicity-biodegradability when AOPs are used as pre-treatment step to improve industrial wastewater biodegradability is also discussed. The main conclusions/remarks include the followings: (i) bioassays are a really useful tool to evaluate the dangerousness of AOPs as well as to set up the proper operative conditions, (ii) target organisms for bioassays should be chosen according to the final use of the treated water matrix, (iii) acute toxicity tests may be not suitable to evaluate toxicity in the presence of low/realistic concentrations of target contaminants, so studies on chronic effects should be further developed, (iv) some toxicity tests may be not useful to evaluate biodegradability potential, in this case more suitable tests should be applied (e.g., activated sludge bioassays, respirometry). PMID:21722938

  4. Application of the CALUX bioassay for epidemiological study. Analyses of Belgian human plasma

    Energy Technology Data Exchange (ETDEWEB)

    Wouwe, N. van; Debacker, N.; Sasse, A. [Scientific Institute of Public Health, Brussels (BE)] (and others)

    2004-09-15

    The CALUX bioassay is a promising screening method for the detection of dioxin-like compounds. The observed good sensitivity, low number of false negative results as well as the good correlations with the GC-HRMS TEQ-values in case of feed and food analyses allow this method to climb in the first assessment methods' scale. The low amount of sample needed in addition to those latest advantages suggest that the CALUX bioassay could be a good screening method for epidemiological studies. The Belgian epidemiological study concerning the possible effect of the dioxin incident on the body burden of the Belgian population was an opportunity to test this method in comparison to the gold reference one: the GC-HRMS. The first part of this abstract presents epidemiological parameters (sensibility, specificity,) of the CALUX bioassay using CALUX TEQ-values as estimators of the TEQ-values of the 17 PCDD/Fs. The second part examines epidemiological determinants observed for CALUX and GCHRMS TEQ-values.

  5. Noninvasive quantitation of human liver steatosis using magnetic resonance and bioassay methods

    Energy Technology Data Exchange (ETDEWEB)

    D' Assignies, Gaspard; Ruel, Martin; Khiat, Abdesslem; Lepanto, Luigi; Kauffmann, Claude; Tang, An [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement de Radiologie, Montreal, Quebec (Canada); Chagnon, Miguel [Universite de Montreal (UDEM), Departement de Mathematiques et de Statistique, Montreal, Quebec (Canada); Gaboury, Louis [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement d' Anatomo-Pathologie, Montreal, Quebec (Canada); Boulanger, Yvan [Centre Hospitalier de l' Universite de Montreal (CHUM), Departement de Radiologie, Montreal, Quebec (Canada); Hopital Saint-Luc du CHUM, Departement de Radiologie, Montreal, Quebec (Canada)

    2009-08-15

    The purpose was to evaluate the ability of three magnetic resonance (MR) techniques to detect liver steatosis and to determine which noninvasive technique (MR, bioassays) or combination of techniques is optimal for the quantification of hepatic fat using histopathology as a reference. Twenty patients with histopathologically proven steatosis and 24 control subjects underwent single-voxel proton MR spectroscopy (MRS; 3 voxels), dual-echo in phase/out of phase MR imaging (DEI) and diffusion-weighted MR imaging (DWI) examinations of the liver. Blood or urine bioassays were also performed for steatosis patients. Both MRS and DEI data allowed to detect steatosis with a high sensitivity (0.95 for MRS; 1 for DEI) and specificity (1 for MRS; 0.875 for DEI) but not DWI. Strong correlations were found between fat fraction (FF) measured by MRS, DEI and histopathology segmentation as well as with low density lipoprotein (LDL) and cholesterol concentrations. A Bland-Altman analysis showed a good agreement between the FF measured by MRS and DEI. Partial correlation analyses failed to improve the correlation with segmentation FF when MRS or DEI data were combined with bioassay results. Therefore, FF from MRS or DEI appear to be the best parameters to both detect steatosis and accurately quantify fat liver noninvasively. (orig.)

  6. Internal dose estimation by bio-assay techniques

    International Nuclear Information System (INIS)

    Radiation exposure, both external and internal, can occur to radiation workers during the operation of various nuclear fuel cycle facilities and radiation facilities. The assessment of radiation doses to workers, routinely or potentially exposed to radiation, through intake of radionuclide is an integral part of the radiation protection programme. Internal dose is the radiation exposure that results from the intake of radioactive materials into the body by inhalation, ingestion, absorption through the skin or via wounds. Assessment of radiation doses arising from the intake of radioactive material by the workers is termed as internal exposure assessment. Unlike external exposure, internal exposure cannot be measured directly. Its evaluation is based on the calculation of the intake of radionuclide either from direct measurements (e.g, external monitoring of whole body or of specific organs and tissues) or indirect measurements (e.g. radioactivity in urine, faeces, breath or samples from the working environment) (ICRP Pub. 78, 1997 and NRPB-W60, 2004). Another method of internal dose assessment is based on the measurement of airborne radionuclides in the working areas of the facility and the worker's occupancy in those areas

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

    Science.gov (United States)

    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.

  8. Laboratory bioassay for assessing the effects of sludge supernatant on plant growth and vesicular-arbuscular mycorrhiza formation

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, K.S.; Liberta, A.E.

    1982-12-01

    A laboratory bioassay is described for assessing the effects of sludge supernatant on juvenile corn growth and the ability of vesicular-arbuscular (VA) mycorrhizal fungi, indigenous to coal spoil, to form mycorrhizae. The bioassay demonstrated that application rates can be identified that have the potential to promote increased plant dry weight without suppressing the formation of VA mycorrhizae in a plant's root system.

  9. Selection of a bioassay battery to assess toxicity in the affluents and effluents of three water-treatment plants

    OpenAIRE

    Paola Bohórquez-Echeverry; Marcela Duarte-Castañeda; Nubia León-López; Claudia Campos-Pinilla; Fabián Caicedo-Carrascal; Myriam Vásquez-Vásquez

    2012-01-01

    The assessment of water quality includes the analysis of both physical-chemical and microbiological parameters. However,none of these evaluates the biological effect that can be generated in ecosystems or humans. In order to define the most suitable organismsto evaluate the toxicity in the affluent and effluent of three drinking-water treatment plants, five acute toxicity bioassays were used,incorporating three taxonomic groups of the food chain. Materials and methods. The bioassays used were...

  10. Sensitivity bioassays of the Cnesterodon decemmaculatus and Pimephales promelasin a series of samples of effluent and reference toxicant

    OpenAIRE

    Gustavo Saona; Agustín Carnikian; Martín Spósito; Patricia Baklayan; Julio Espínola

    2015-01-01

    This study compared the toxicological sensitivity quantified by the 50% lethal dose of acute toxicity bioassays of Cnesterodon decemmaculatusand Pimephales promelasin benchmark exposure to toxic industrial effluents, wastewater effluents and reference toxicants. At the same time, the toxicological sensitivity of C. decemmaculatusrelated to the size was assayed. Both species were analyzed with 16 bioassays mated by the same substance or compound and a good agreement rL= 0.75 was observed. No s...

  11. Beoordeling van gereinigde grond. V. Toepassing van bioassays met planten en regenwormen op verontreinigde en gereinigde gronden

    OpenAIRE

    Gestel CAM van; Dirven-van Breemen EM; Kamerman JW

    1992-01-01

    Within the framework of the project "Evaluation of decontaminated soil", the applicability of bioassays with earthworms and plants for the quality assessment of decontaminated soil is investigated. In the final phase of this project, bioassays with earthworms and plants (radish, lettuce) developed earlier, were applied to a number of polluted and decontaminated soils. As earlier studies demonstrated that bioavailability of metals increased due to clean-up operations, the decontamina...

  12. Earthworm Preference Bioassays to Evaluate Land Management Practices.

    Science.gov (United States)

    Bouldin, Jennifer L; Klasky, John W P; Green, V Steven

    2016-06-01

    Earthworm preference tests, especially in soil-dosed exposures, can be an informative tool for assessing land management practices. Agricultural management intended to increase crop yield and improve soil sustainability includes physical manipulation of topsoil through conventional tillage, reduced or no-tillage, and/or winter cover crops. Soil amendments include the addition of inorganic nitrogen or organic nitrogen derived from soil amendments including biosolids from sewage treatment plants, poultry litter, or locally available industrial effluent. This study used 48-h Eisenia fetida preference tests to assess impacts of agricultural management practices on soil macrofauna. Although in laboratory-dosed exposures, E. fetida preferred biosolid-dosed soils (80 %-95 % recovery) over control soils, the same results were not found with field soils receiving biosolid amendments (33 % recovery). Poultry litter-amended soils (68 % recovery) were preferred over control soils. No differences were measured between tilled fields and controls, and earthworms preferred control soils over those from fields with no-tillage and cover crops. Soil assessments through laboratory exposures such as these allows science-based agricultural management decisions to maintain or improve soil health.

  13. Assessing biochar ecotoxicology for soil amendment by root phytotoxicity bioassays.

    Science.gov (United States)

    Visioli, Giovanna; Conti, Federica D; Menta, Cristina; Bandiera, Marianna; Malcevschi, Alessio; Jones, Davey L; Vamerali, Teofilo

    2016-03-01

    Soil amendment with biochar has been proposed as effective in improving agricultural land fertility and carbon sequestration, although the characterisation and certification of biochar quality are still crucial for widespread acceptance for agronomic purposes. We describe here the effects of four biochars (conifer and poplar wood, grape marc, wheat straw) at increasing application rates (0.5, 1, 2, 5, 10, 20, 50% w/w) on both germination and root elongation of Cucumis sativus L., Lepidium sativum L. and Sorghum saccharatum Moench. The tested biochars varied in chemical properties, depending on the type and quality of the initial feedstock batch, polycyclic aromatic hydrocarbons (PAHs) being high in conifer and wheat straw, Cd in poplar and Cu in grape marc. We demonstrate that electrical conductivity and Cu negatively affected both germination and root elongation at ≥5% rate biochar, together with Zn at ≥10% and elevated pH at ≥20%. In all species, germination was less sensitive than root elongation, strongly decreasing at very high rates of chars from grape marc (>10%) and wheat straw (>50%), whereas root length was already affected at 0.5% of conifer and poplar in cucumber and sorghum, with marked impairment in all chars at >5%. As a general interpretation, we propose here logarithmic model for robust root phytotoxicity in sorghum, based on biochar Zn content, which explains 66% of variability over the whole dosage range tested. We conclude that metal contamination is a crucial quality parameter for biochar safety, and that root elongation represents a stable test for assessing phytotoxicity at recommended in-field amendment rates (<1-2%). PMID:26884353

  14. Assessing biochar ecotoxicology for soil amendment by root phytotoxicity bioassays.

    Science.gov (United States)

    Visioli, Giovanna; Conti, Federica D; Menta, Cristina; Bandiera, Marianna; Malcevschi, Alessio; Jones, Davey L; Vamerali, Teofilo

    2016-03-01

    Soil amendment with biochar has been proposed as effective in improving agricultural land fertility and carbon sequestration, although the characterisation and certification of biochar quality are still crucial for widespread acceptance for agronomic purposes. We describe here the effects of four biochars (conifer and poplar wood, grape marc, wheat straw) at increasing application rates (0.5, 1, 2, 5, 10, 20, 50% w/w) on both germination and root elongation of Cucumis sativus L., Lepidium sativum L. and Sorghum saccharatum Moench. The tested biochars varied in chemical properties, depending on the type and quality of the initial feedstock batch, polycyclic aromatic hydrocarbons (PAHs) being high in conifer and wheat straw, Cd in poplar and Cu in grape marc. We demonstrate that electrical conductivity and Cu negatively affected both germination and root elongation at ≥5% rate biochar, together with Zn at ≥10% and elevated pH at ≥20%. In all species, germination was less sensitive than root elongation, strongly decreasing at very high rates of chars from grape marc (>10%) and wheat straw (>50%), whereas root length was already affected at 0.5% of conifer and poplar in cucumber and sorghum, with marked impairment in all chars at >5%. As a general interpretation, we propose here logarithmic model for robust root phytotoxicity in sorghum, based on biochar Zn content, which explains 66% of variability over the whole dosage range tested. We conclude that metal contamination is a crucial quality parameter for biochar safety, and that root elongation represents a stable test for assessing phytotoxicity at recommended in-field amendment rates (<1-2%).

  15. Coupling passive sampling with in vitro bioassays and chemical analysis to understand combined effects of bioaccumulative chemicals in blood of marine turtles.

    Science.gov (United States)

    Jin, Ling; Escher, Beate I; Limpus, Colin J; Gaus, Caroline

    2015-11-01

    Conventional target analysis of biological samples such as blood limits our ability to understand mixture effects of chemicals. This study aimed to establish a rapid passive sampling technique using the polymer polydimethylsiloxane (PDMS) for exhaustive extraction of mixtures of neutral organic chemicals accumulated in blood of green turtles, in preparation for screening in in vitro bioassays. We designed a PDMS-blood partitioning system based on the partition coefficients of chemicals between PDMS and major blood components. The sampling kinetics of hydrophobic test chemicals (polychlorinated dibenzo-p-dioxins; PCDDs) from blood into PDMS were reasonably fast reaching steady state in turtles with known concentrations of PCDD/Fs, dioxin-like PCBs, PBDEs and organochlorine pesticides. The quantified chemicals explained most of the dioxin-like activity (69-98%), but less than 0.4% of the oxidative stress response. The results demonstrate the applicability of PDMS-based passive sampling to extract bioaccumulative chemicals from blood as well as the value of in vitro bioassays for capturing the combined effects of unknown and known chemicals.

  16. Anaerobic bioassay of methane potential of microalgal biomass

    Science.gov (United States)

    Yen, Hong-Wei

    This study was undertaken to investigate the feasibility of using anaerobic digestion as a technique to recover solar energy embodied in excess algal biomass production harvested from Clemson University's high rate algal based Partitioned Aquaculture System (PAS) as an energy source to support PAS operations. In this study, four different organic substrates were loaded to anaerobic digesters in eight experimental trials, to ascertain the optimal combination of operational variables and effect of algal, or modified algal substrate upon methane production rate. The four substrates used in this study were: (1) a synthetic feedstock consisting of molasses and dog food, (2) a commercially obtained, readily degradable algal biomass (Spirulina ) in dry form, (3) PAS harvested and dewatered algal sludge, and (4) algal biomass blended with shredded waste paper or molasses as a carbon supplement for the adjustment of algal C/N ratio. Eight experimental trials using combinations of the four substrates were conducted in 15 liter digesters to investigate the effects of controlled digester parameters upon digester performance. Digesters operating at 20 days HRT, mesophilic digestion (35°C), and twice per day mixing at maximal loading rates produced maximal methane gas using PAS algal sludge. However, under these conditions overall methane production was less than 1000 ml CH4/l day. This low level of energy recovery from the fermentation of algal biomass (alone) is not energetically or economically favorable. Co-digestion of algal sludge and waste paper was investigated as a way to increase methane production. The data obtained from these trials suggest an optimum C/N ratio for co-digestion of algal sludge and waste paper in the range of 20--25/l. A balanced C/N ratio along with the stimulated increase in cellulase activity is suggested as likely reasons for increased methane production seen in co-digestion of algal sludge and waste paper. Yeast extract addition to anaerobic

  17. Evaluation of mixture effects in a crude extract of compost using the CALUX bioassay and HPLC fractionation

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, G.; Takigami, H.; Sakai, S.I. [National Inst. for Environmental Studies, Yatabe, Ibaraki (Japan). Research Center for Material Cycles and Waste Management; Kushi, Y. [Obihiro Univ. of Agriculture and Veternary Medicine (Japan). Dept. of Bioresource Science

    2004-09-15

    In general, crude extracts and polyaromatic hydrocarbon (PAC)-containing fractions of environmental samples show high activities in the AHR-based bioassay. Although many studies have tried to determine which compounds contribute to this activity based on additivity theory, these values are higher than the corresponding chemically calculated IEQs or TEQ values. These compounds in environmental samples exist as mixtures, and interactions between compounds must be considered in chemical risk assessments. In particular, if synergistic interactions occur in environmental samples, application of the additivity assessment would underestimate real chemical risk. In this study, we investigated mixture effects in an extract of an environmental sample. First we established a simple fractionation procedure for the sample, and then we examined the retention characteristics of PACs using RP-HPLC on an octadecylsilica (ODS) column. Then we applied HPLC fractionation and combined CALUX (DR-CALUX {sup registered}: Dioxin-Responsive Chemical- Activated Luciferase gene expression)/chemical analysis to a night soil sludge (NSS) compost extract to determine which compounds contributed to the CALUX-TEQ (2,3,7,8-TCDD equivalent) of the crude extract. Finally, to assess the mixture effects, we exposed the HPLC fractions to CALUX cells in the presence of 2,3,7,8-TCDD at concentration levels similar to those in the original compost sample and determined whether there was a synergistic interaction between the sample fraction and 2,3,7,8-TCDD in terms of CALUX activity.

  18. Characterization and bioassay for larvicidal activity of Anacardium occidentale (cashew) shell waste fractions against dengue vector Aedes aegypti.

    Science.gov (United States)

    Torres, Rosalinda C; Garbo, Alicia G; Walde, Rikkamae Zinca Marie L

    2015-10-01

    Recent studies regarding the harmful effects of synthetic larvicides initiated the need to investigate for unconventional measures that are environmentally safe and target-specific against Aedes aegypti larvae. Thus, the main objectives of the study are to evaluate the larvicidal toxicity of the solvent fractions of Anacardium occidentale shell wastes against the third and fourth instar larvae of A. aegypti and to compare the results with the commercial larvicide product. The shell wastes were extracted with 95% EtOH followed by polarity-based fractionation. The fractions were tested for larvicidal activity according to the World Health Organization bioassay method. These were then characterized by quantitative thin-layer chromatographic (TLC) fingerprinting. The hexane fraction gave the strongest activity among the fractions with an LC50 of 4.01 mg/L and LC90 of 11.29 mg/L highly comparable to the commercial larvicide, which exhibited an LC50 of 1.71 mg/L and LC90 of 8.41 mg/L. The dichloromethane fraction exhibited 9.70 mg/L LC50 and 18.44 mg/L LC90. The remarkable toxicity effects exhibited by these fractions indicate their potential to provide core structures from which sustainable and environmentally safe plant-based larvicidal agents can be synthesized.

  19. Analysis of Bioactive Components of Oilseed Cakes by High-Performance Thin-Layer Chromatography-(Bioassay Combined with Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Sue-Siang Teh

    2015-03-01

    Full Text Available Hemp, flax and canola seed cakes are byproducts of the plant oil extraction industry that have not received much attention in terms of their potential use for human food instead of animal feed. Thus, the bioactivity profiling of these oilseed cakes is of interest. For their effect-directed analysis, planar chromatography was combined with several (bioassays, namely 2,2-diphenyl-1-picrylhydrazyl scavenging, acetylcholine esterase inhibition, planar yeast estrogen screen, antimicrobial Bacillus subtilis and Aliivibrio fischeri assays. The streamlined high-performance thin-layer chromatography (HPTLC-bioassay method allowed the discovery of previously unknown bioactive compounds present in these oilseed cake extracts. In contrast to target analysis, the direct link to the effective compounds allowed comprehensive information with regard to selected effects. HPTLC-electrospray ionization-mass spectrometry via the elution-head based TLC-MS Interface was used for a first characterization of the unknown effective compounds. The demonstrated bioactivity profiling on the feed/food intake side may guide the isolation of active compounds for production of functional food or for justified motivation of functional feed/food supplements.

  20. Mass spectrometric profiling of Bacillus cereus strains and quantitation of the emetic toxin cereulide by means of stable isotope dilution analysis and HEp-2 bioassay.

    Science.gov (United States)

    Stark, Timo; Marxen, Sandra; Rütschle, Andrea; Lücking, Genia; Scherer, Siegfried; Ehling-Schulz, Monika; Hofmann, Thomas

    2013-01-01

    A fast and robust high-throughput ultra-performance liquid chromatography/time-of-flight mass spectrometry (UPLC-TOF MS) profiling method was developed and successfully applied to discriminate a total of 78 Bacillus cereus strains into no/low, medium and high producers of the emetic toxin cereulide. The data obtained by UPLC-TOF MS profiling were confirmed by absolute quantitation of cereulide in selected samples by means of high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) and stable isotope dilution assay (SIDA). Interestingly, the B. cereus strains isolated from four vomit samples and five faeces samples from patients showing symptoms of intoxication were among the group of medium or high producers. Comparison of HEp-2 bioassay data with those determined by means of mass spectrometry showed differences, most likely because the HEp-2 bioassay is based on the toxic action of cereulide towards mitochondria of eukaryotic cells rather than on a direct measurement of the toxin. In conclusion, the UPLC-electrospray ionization (ESI)-TOF MS and the HPLC-ESI-MS/MS-SIDA analyses seem to be promising tools for the robust high-throughput analysis of cereulide in B. cereus cultures, foods and other biological samples.

  1. Estrogen bioactivity in fo-ti and other herbs used for their estrogen-like effects as determined by a recombinant cell bioassay.

    Science.gov (United States)

    Oerter Klein, Karen; Janfaza, Mona; Wong, Jeffrey A; Chang, R Jeffrey

    2003-09-01

    One of the most important issues in women's health concerns the risks and benefits of estrogen replacement therapy. Continual uncertainty and lack of consensus regarding estrogen replacement therapy has driven many women to seek alternative sources of estrogen, including herbal remedies. We adapted a recombinant cell bioassay to measure estrogen bioactivity in herbs. We studied, in vitro, estrogen bioactivity in red clover, dong quai, black cohosh, soy, licorice, chaste tree berry, fo-ti, and hops. Soy, clover, licorice, and hops have a large amount of measurable estrogen bioactivity, as suspected, based on previous reports using other methods. We discovered surprisingly high estrogen activity in extracts of fo-ti not previously reported. Chaste tree berry, black cohosh, and dong quai did not have measurable activity with this method. We also discovered that removal of a glycone group from soy increases its estrogen bioactivity significantly. We conclude that this recombinant cell bioassay for estradiol can be used to measure bioactivity in herbal products. The preparations of fo-ti studied had estrogen activity of 409 +/- 55 pmol/liter estradiol equivalents per microgram of herb, which is 1/300 the activity of 17 beta-estradiol. Clinical studies are underway to determine the estrogen bioactivity in women using dietary supplements containing these herbs. PMID:12970265

  2. Oversimplification and overstandardization in biological methods: sperm bioassays in ecotoxicology as a case of study and a proposal for their reformulation.

    Science.gov (United States)

    Murado, M A; Prieto, M A

    2014-01-01

    An interesting toxicological bioassay (fertilization inhibition in sea urchin) uses as assessment criterion a variable (fertilization ratio) whose variation with time creates two types of difficulties. First, it fails to distinguish between the toxic effect and the spontaneous decline in the sperm activity, causing some inconsistencies. Second, the sensitivity of the fertilization ratio to many other variables of the system requires a complex standardization, constraining the achievement of the method without solving its main problem. Our proposal consists of using a parameter (sperm half-life) as the response of the assay, and describing explicitly the behavior of the system as a simultaneous function of dose and time. This new focus is able to solve the problematic character of the results based on the fertilization ratio and by using the same data set which is required by the conventional approach; it simplifies the protocol, economizes experimental effort, provides unambiguous and robust results, and contributes to the detection of an artefactual temperature effect, which is not very evident under the usual perspective. Potential application of this new approach to the improvement of other formally similar bioassays is finally suggested.

  3. Development of an edema factor-mediated cAMP-induction bioassay for detecting antibody-mediated neutralization of anthrax protective antigen.

    Science.gov (United States)

    Zmuda, Jonathan F; Zhang, Linyi; Richards, Terri; Pham, Quyen; Zukauskas, David; Pierre, Jennifer L; Laird, Michael W; Askins, Janine; Choi, Gil H

    2005-03-01

    Intoxication of mammalian cells by Bacillus anthracis requires the coordinate activity of three distinct bacterial proteins: protective antigen (PA), edema factor (EF), and lethal factor (LF). Among these proteins, PA has become the major focus of work on monoclonal antibodies and vaccines designed to treat or prevent anthrax infection since neither EF nor LF is capable of inducing cellular toxicity in its absence. Here, we present the development of a sensitive, precise, and biologically relevant bioassay platform capable of quantifying antibody-mediated PA neutralization. This bioassay is based on the ability of PA to bind and shuttle EF, a bacterial adenylate cyclase, into mammalian cells leading to an increase in cAMP that can be quantified using a sensitive chemiluminescent ELISA. The results of this study indicate that the cAMP-induction assay possesses the necessary performance characteristics for use as both a potency-indicating release assay in a quality control setting and as a surrogate pharmacodynamic marker for ensuring the continued bioactivity of therapeutic antibodies against PA during clinical trials. PMID:15847796

  4. Polyvinyl polypyrrolidone attenuates genotoxicity of silver nanoparticles synthesized via green route, tested in Lathyrus sativus L. root bioassay.

    Science.gov (United States)

    Panda, Kamal K; Achary, V Mohan M; Phaomie, Ganngam; Sahu, Hrushi K; Parinandi, Narasimham L; Panda, Brahma B

    2016-08-01

    The silver nanoparticles (AgNPs) were synthesized extracellularly from silver nitrate (AgNO3) using kernel extract from ripe mango Mengifera indica L. under four different reaction conditions of the synthesis media such as the (i) absence of the reducing agent, trisodium citrate (AgNPI), (ii) presence of the reducing agent (AgNPII), (iii) presence of the cleansing agent, polyvinyl polypyrrolidone, PVPP (AgNPIII), and (iv) presence of the capping agent, polyvinyl pyrrolidone, PVP (AgNPIV). The synthesis of the AgNPs was monitored by UV-vis spectrophotometry. The AgNPs were characterised by the energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and small-angle X-ray scattering. Functional groups on the AgNPs were established by the Fourier transform infrared spectroscopy. The AgNPs (AgNPI, AgNPII, AgNPIII and AgNPIV) were spherical in shape with the diameters and size distribution-widths of 14.0±5.4, 19.2±6.6, 18.8±6.6 and 44.6±13.2nm, respectively. Genotoxicity of the AgNPs at concentrations ranging from 1 to 100mgL(-1) was determined by the Lathyrus sativus L. root bioassay and several endpoint assays including the generation of reactive oxygen species and cell death, lipid peroxidation, mitotic index, chromosome aberrations (CA), micronucleus formation (MN), and DNA damage as determined by the Comet assay. The dose-dependent induction of genotoxicity of the silver ion (Ag(+)) and AgNPs was in the order Ag(+)>AgNPII>AgNPI>AgNPIV>AgNPIII that corresponded with their relative potencies of induction of DNA damage and oxidative stress. Furthermore, the findings underscored the CA and MN endpoint-based genotoxicity assay which demonstrated the genotoxicity of AgNPs at concentrations (≤10mgL(-1)) lower than that (≥10mgL(-1)) tested in the Comet assay. This study demonstrated the protective action of PVPP against the genotoxicity of AgNPIII which was independent of the size of the AgNPs in the L. sativus L. root bioassay

  5. A novel method for standardized application of fungal spore coatings for mosquito exposure bioassays

    Directory of Open Access Journals (Sweden)

    Knols Bart GJ

    2010-01-01

    Full Text Available Abstract Background Interest in the use of fungal entomopathogens against malaria vectors is growing. Fungal spores infect insects via the cuticle and can be applied directly on the insect to evaluate infectivity. For flying insects such as mosquitoes, however, application of fungal suspensions on resting surfaces is more realistic and representative of field settings. For this type of exposure, it is essential to apply specific amounts of fungal spores homogeneously over a surface for testing the effects of fungal dose and exposure time. Contemporary methods such as spraying or brushing spore suspensions onto substrates do not produce the uniformity and consistency that standardized laboratory assays require. Two novel fungus application methods using equipment developed in the paint industry are presented and compared. Methods Wired, stainless steel K-bars were tested and optimized for coating fungal spore suspensions onto paper substrates. Different solvents and substrates were evaluated. Two types of coating techniques were compared, i.e. manual and automated coating. A standardized bioassay set-up was designed for testing coated spores against malaria mosquitoes. Results K-bar coating provided consistent applications of spore layers onto paper substrates. Viscous Ondina oil formulations were not suitable and significantly reduced spore infectivity. Evaporative Shellsol T solvent dried quickly and resulted in high spore infectivity to mosquitoes. Smooth proofing papers were the most effective substrate and showed higher infectivity than cardboard substrates. Manually and mechanically applied spore coatings showed similar and reproducible effects on mosquito survival. The standardized mosquito exposure bioassay was effective and consistent in measuring effects of fungal dose and exposure time. Conclusions K-bar coating is a simple and consistent method for applying fungal spore suspensions onto paper substrates and can produce coating layers

  6. Using a macroalgal δ15N bioassay to detect cruise ship waste water effluent inputs

    International Nuclear Information System (INIS)

    Highlights: → Green macroalgae exposed to nutrient solutions exhibited changes in tissue 15N signatures. → Macroalgae exhibited no fractionation with NO3 and slight fractionation with NH4. → Algae exposed to cruise ship waste water had increased tissue δ15N indicating a heavy N source. → Field bioassays exhibited decreased δ15N indicating isotopically light riverine δ15N-NO3 was likely the dominant N source. → Algal bioassays could not detect a δ15N cruise ship waste water signal in this system. - Abstract: Green macroalgae bioassays were used to determine if the δ15N signature of cruise ship waste water effluent (CSWWE) could be detected in a small harbor. Opportunistic green macroalgae (Ulva spp.) were collected, cultured under nutrient depleted conditions and characterized with regard to N content and δ15N. Samples of algae were used in controlled incubations to evaluate the direction of isotope shift from exposure to CSWWE. Algae samples exposed to CSWWE exhibited an increase of 1-2.5 per mille in δ15N values indicating that the CSWWE had an enriched isotope signature. In contrast, algae samples exposed to field conditions exhibited a significant decrease in the observed δ15N indicating that a light N source was used. Isotopically light, riverine nitrogen derived from N2-fixing trees in the watershed may be a N source utilized by algae. These experiments indicate that the δ15N CSWWE signature was not detectable under the CSWWE loading conditions of this experiment.

  7. Guidance document for prepermit bioassay testing of low-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, S.L.; Harrison, F.L.

    1990-11-01

    In response to the mandate of Public Law 92-532, the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972, as amended, the Environmental Protection Agency (EPA) has developed a program to promulgate regulations and criteria to control the ocean disposal of radioactive wastes. The EPA seeks to understand the mechanisms for biological response of marine organisms to the low levels of radioactivity that may arise from the release of these wastes as a result of ocean-disposal practices. Such information will play an important role in determining the adequacy of environmental assessments provided to the EPA in support of any disposal permit application. Although the EPA requires packaging of low-level radioactive waste to prevent release during radiodecay of the materials, some release of radioactive material into the deep-sea environment may occur when a package deteriorates. Therefore, methods for evaluating the impact on biota are being evaluated. Mortality and phenotypic responses are not anticipated at the expected low environmental levels that might occur if radioactive materials were released from the low-level waste packages. Therefore, traditional bioassay systems are unsuitable for assessing sublethal effects on biota in the marine environment. The EPA Office of Radiation Programs (ORP) has had an ongoing program to examine sublethal responses to radiation at the cellular level, using cytogenetic end points. This technical guidance report represents prepermit bioassay procedures that potentially may be applicable to the assessment of effects from a mixture of radionuclides that could be released from a point source at the ocean bottom. Methodologies along with rationale and a discussion of uncertainty are presented for the sediment benthic bioassay protocols identified in this report.

  8. Guidance document for prepermit bioassay testing of low-level radioactive waste

    International Nuclear Information System (INIS)

    In response to the mandate of Public Law 92-532, the Marine Protection, Research, and Sanctuaries Act (MPRSA) of 1972, as amended, the Environmental Protection Agency (EPA) has developed a program to promulgate regulations and criteria to control the ocean disposal of radioactive wastes. The EPA seeks to understand the mechanisms for biological response of marine organisms to the low levels of radioactivity that may arise from the release of these wastes as a result of ocean-disposal practices. Such information will play an important role in determining the adequacy of environmental assessments provided to the EPA in support of any disposal permit application. Although the EPA requires packaging of low-level radioactive waste to prevent release during radiodecay of the materials, some release of radioactive material into the deep-sea environment may occur when a package deteriorates. Therefore, methods for evaluating the impact on biota are being evaluated. Mortality and phenotypic responses are not anticipated at the expected low environmental levels that might occur if radioactive materials were released from the low-level waste packages. Therefore, traditional bioassay systems are unsuitable for assessing sublethal effects on biota in the marine environment. The EPA Office of Radiation Programs (ORP) has had an ongoing program to examine sublethal responses to radiation at the cellular level, using cytogenetic end points. This technical guidance report represents prepermit bioassay procedures that potentially may be applicable to the assessment of effects from a mixture of radionuclides that could be released from a point source at the ocean bottom. Methodologies along with rationale and a discussion of uncertainty are presented for the sediment benthic bioassay protocols identified in this report

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

    Energy Technology Data Exchange (ETDEWEB)

    Thain, J.; Matthiessen, P.

    1995-12-31

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

  10. Promising Aedes aegypti repellent chemotypes identified through integrated QSAR, virtual screening, synthesis, and bioassay.

    Science.gov (United States)

    Oliferenko, Polina V; Oliferenko, Alexander A; Poda, Gennadiy I; Osolodkin, Dmitry I; Pillai, Girinath G; Bernier, Ulrich R; Tsikolia, Maia; Agramonte, Natasha M; Clark, Gary G; Linthicum, Kenneth J; Katritzky, Alan R

    2013-01-01

    Molecular field topology analysis, scaffold hopping, and molecular docking were used as complementary computational tools for the design of repellents for Aedes aegypti, the insect vector for yellow fever, chikungunya, and dengue fever. A large number of analogues were evaluated by virtual screening with Glide molecular docking software. This produced several dozen hits that were either synthesized or procured from commercial sources. Analysis of these compounds by a repellent bioassay resulted in a few highly active chemicals (in terms of minimum effective dosage) as viable candidates for further hit-to-lead and lead optimization effort.

  11. NTP Workshop: Animal Models for the NTP Rodent Cancer Bioassay: Stocks and Strains - Should We Switch?

    OpenAIRE

    King-Herbert, Angela; Thayer, Kristina

    2006-01-01

    The National Toxicology Program (NTP) hosted a workshop, “Animal Models for the NTP Rodent Cancer Bioassay: Strains & Stocks -- Should We Switch?” on June 16-17, 2005, at the National Institute of Environmental Health Sciences (NIEHS) in Research Triangle Park, NC. The workshop’s objectives were to determine (1) whether the currently used models, the F344/N rat and B6C3F1/N mouse, continue to be appropriate to identify substances that may pose a carcinogenic hazard for humans and (2) whether ...

  12. Identification and bioassay of sex pheromone components of carob moth,Ectomyelois ceratoniae (Zeller).

    Science.gov (United States)

    Baker, T C; Francke, W; Millar, J G; Löfstedt, C; Hansson, B; Du, J W; Phelan, P L; Vetter, R S; Youngman, R; Todd, J L

    1991-10-01

    Three sex pheromone components of the carob moth were isolated and identified from the extract of female pheromone glands, using a variety of techniques including coupled gas chromatographic-electroantennographic recordings, coupled gas chromatographic-mass spectrometric analysis, microozonolysis, electroantennographic assays of monounsaturated standards, wind-tunnel bioassays, and field trials. The major component was identified as (Z,E)-9,11,13-tetradecatrienal, a novel lepidopterous pheromone component structure. Two minor components, either one of which improves the upwind flight response of males when blended with the major component, were identified as (Z,E)-9,11-tetradecadienal, and (Z)-9-tetra-decenal.

  13. Toxicity assessment of effluent from flash light manufacturing industry by bioassay tests in Trigonella foenumgracum.

    Science.gov (United States)

    Kumari, Narendra; Kumar, Sanjeev; Bauddh, Kuldeep; Dwivedi, Neetu; Singh, D P; Barman, S C

    2014-11-01

    A rapid bioassay test was conducted to study heavy metal accumulation and biochemical changes in Trigonella foenumgracum (methi) irrigated with 25, 50, 75 and 100% of effluent from flash light manufacturing industry at 60 days after sowing. Total metal concentration in effluent samples was: Cr = 0.12 effluent followed by a decrease at higher concentration as compared to their respective control.An enhanced lipid peroxidation in the treated plants was observed, which was evident by increased level of antioxidants: proline, cysteine, malondialdehyde and ascorbic acid content. The treated plants accumulated metals in the following order: Cu > Pb > Cr > Cd in the roots and shoots. PMID:25522513

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

    Directory of Open Access Journals (Sweden)

    Claudia Scherr

    Full Text Available 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. METHODOLOGY/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

  15. Bioassay-guided isolation and identification of an antibacterial compound from Ferula persica var. persica roots

    Directory of Open Access Journals (Sweden)

    Ahmad-Reza Shahverdi

    2005-01-01

    Full Text Available The antibacterial activities of the chloroform and water extracts of Ferula persica var. persica (Apiaceaeroots were studied by the disk diffusion method. While the chloroform extract of F. persica roots showed antibacterial activity, the water extract of the roots at the concentrations that tested did not show any activity. By bioassay-guided fractionation of the chloroform extract of the roots by preparative thin layer chromatography (PTLC a compound was found which was active against some bacteria. By conventional spectroscopy methods the active fraction was identified as umbelliprenin. This coumarin was mostly active against B. subtillis, B. cereus, E. coli, K. ponumoniae, S. typhi, S. aureus, and S. epidermilis.

  16. Comparison of chronic toxicity and carcinogenicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in two-year bioassays in female Sprague-Dawley rats

    OpenAIRE

    Walker, Nigel J.; Wyde, Michael E.; Fischer, Lawrence J.; Nyska, Abraham; Bucher, John R

    2006-01-01

    The cancer bioassay for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) conducted by the Dow Chemical company in the mid 70s been used extensively for conducting quantitative cancer risk assessments for human exposure to TCDD. More recently the National Toxicology Program (NTP) conducted a cancer bioassay of similar design as part of its evaluation of the dioxin TEF methodology. This report compares the design and the results of these two cancer bioassays. This comparison confirms, in most cases, ...

  17. Radiomutagenesis and an in vitro conductimetric bioassay: it's application to avocado improvement for Phytophthora spp. resistance

    International Nuclear Information System (INIS)

    Avocado root-rot, caused by Phytophtora cinnamomi is among the main biotic stresses causing important economic losses to the crop. Therefore, development and identification of new genotypes resistant to the pathogen is important for an integrated disease management. However, limitations to avocado breeding and production are also related to the long juvenile period, large cultivation areas and extensive natural cross-pollination. In this sense, radiomutagenesis has proven to be a valuable tool to improve disease resistance in fruit trees. For this, the determination of mutagenic doses, combined with in vitro selection and conductimetric bioassays are necessary to accelerate the mutation breeding schemes. In avocado, the measurement of electrical conductivity, based on the release of microelectrolytes to the medium due to cell permeability damage, has been performed on inoculated roots and leaves. In the present work is showed a report of mutagenic doses against gamma rays (LD50 and LD20) determined for in vitro propagated zygotic embryos of three avocado cultivars. Additionally, electric conductivity was measured in leaf discs and root segments from zygotic embryos of Catalina cv. challenged with culture filtrates of isolates from different regions of the country. The results indicated a differential response of the genotype depending on the strain used. Also, differential response was observed, depending on tissue type

  18. Evaluation of genotoxicity from low exposure rates of ionizing radiation by using Trad-MCN bioassay

    International Nuclear Information System (INIS)

    The biomonitoring has been recognized as an important tool in the field of environmental studies. Biological assays have been used to evaluate genotoxic agents present in the environment. Among the bioassays using plants, the micronucleus tests of Tradescantia sp. (Trad-MCN) has shown sensitivity to several environmental conditions, including radiation. Several studies have demonstrated that Tradescantia sp. is sensitive to the harmful effects of X-rays, internal and external radioisotopic sources and cosmic rays. The toxicity is evaluated by observing the frequency of broken chromosomes presented as a small rounded structure in the pollen cells (tetrads), called micronucleus. The present study was developed in Centro Experimental Aramar where, since the 80's, an Environmental Monitoring Program has been carried out by the Radioecological Laboratory. The purpose of this work was to evaluate, by using the Trad-MCN bioassay, the genotoxicity from low exposure rates of ionizing radiation on Tradescantia pallida inflorescences exposed to a uranium ore, in a closed dynamic system. The plants were also submitted to a control exposure with filtered air (negative control). The assay was developed according to the usual protocol. Micronuclei frequencies were compared using Kruskal-Wallis variance analysis. The negative control presented a significantly different micronuclei frequency from all the groups exposed to radiation (P -1). The obtained results indicated that T. pallida is sensitive to ionizing radiation even in low exposure rates and it can be used for in vitro environmental monitoring(author)

  19. Aggregating Behavior of Phenolic Compounds — A Source of False Bioassay Results?

    Directory of Open Access Journals (Sweden)

    Päivi Tammela

    2012-09-01

    Full Text Available Previous descriptions of quercetin, a widely studied flavonoid, as a frequently reported nonspecific screening hit due to aggregating behavior has raised questions about the reliability of in vitro bioactivity reports of phenolic compounds. Here a systematic study on 117 phenolic compounds is presented, concerning their aggregating tendency and the relevance of this phenomenon to obtaining false bioassay results. Fourteen compounds formed aggregates detectable by dynamic light scattering (DLS when assayed at 10 µM in Tris-HCl pH 7.5. Flavonoids were more prone to aggregation than other phenolic compounds, and the aggregate formation was highly dependent on the vehicle, ionic strength and pH. The compounds were also assayed against three unrelated enzymes in the presence and absence of Triton X-100, and their bioactivity ratios were collected from PubChem database. By comparing these datasets, quercetin and rhamnetin were confirmed as promiscuous inhibitors. In general, flavonoids exhibited also higher bioactivity ratios in the PubChem database than coumarins or organic acids. To conclude, aggregate formation can be controlled with Triton X-100 and this phenomenon needs to be considered when bioassay data is interpreted, but our data indicates that it does not always lead to unspecific inhibition of biological targets.

  20. Bioassay for Detection of Dichlorvos Insecticide in Air in Alfalfa Leafcutting Bee (Megachile Rotundata F. Incubators

    Directory of Open Access Journals (Sweden)

    Purdy John R.

    2014-12-01

    Full Text Available Dichlorvos is an insecticide used in slow-release plastic strips for controlling chalcid wasp parasites, such as Pteromalus venustus Walker, in incubators used to raise alfalfa leafcutting bees (Megachile rotundata F.. Beekeepers need a practical method to detect dichlorvos in air and verify that it has dissipated to levels acceptable for worker re-entry and for the bees to emerge. We evaluated three methods for analysis of the dichlorvos concentration in air. Vapor sampling tubes using a manually operated pump or diffusion collection had insufficient sensitivity in the concentration range of interest. Air samples collected using battery powered pumps were analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS, which was accurate and sensitive, but too costly and slow for practical use. Finally, a convenient bioassay for detecting dichlorvos in air was developed using leafcutting bees and verified by comparison with the results obtained by LC/MS/MS for a series of dose levels. The bioassay is simple enough to be done by the beekeeper on-site, is inexpensive, and gives results within 1 h. The LC50 for dichlorvos vapor in air after 1 h of exposure was 273.2 μg/m3 by the probit regression method or 277.3 μg/m3 by the logit regression method.

  1. High performance wash-free magnetic bioassays through microfluidically enhanced particle specificity.

    Science.gov (United States)

    Bechstein, Daniel J B; Lee, Jung-Rok; Ooi, Chin Chun; Gani, Adi W; Kim, Kyunglok; Wilson, Robert J; Wang, Shan X

    2015-06-30

    Magnetic biosensors have emerged as a sensitive and versatile platform for high performance medical diagnostics. These magnetic biosensors require well-tailored magnetic particles as detection probes, which need to give rise to a large and specific biological signal while showing very low nonspecific binding. This is especially important in wash-free bioassay protocols, which do not require removal of particles before measurement, often a necessity in point of care diagnostics. Here we show that magnetic interactions between magnetic particles and magnetized sensors dramatically impact particle transport and magnetic adhesion to the sensor surfaces. We investigate the dynamics of magnetic particles' biomolecular binding and magnetic adhesion to the sensor surface using microfluidic experiments. We elucidate how flow forces can inhibit magnetic adhesion, greatly diminishing or even eliminating nonspecific signals in wash-free magnetic bioassays, and enhancing signal to noise ratios by several orders of magnitude. Our method is useful for selecting and optimizing magnetic particles for a wide range of magnetic sensor platforms.

  2. Antimicrobial Activity and Brine Shrimp Lethality Bioassay of the Leaves Extract of Dillenia indica Linn.

    Science.gov (United States)

    Apu, As; Muhit, Ma; Tareq, Sm; Pathan, Ah; Jamaluddin, Atm; Ahmed, M

    2010-01-01

    The crude methanolic extract of Dillenia indica Linn. (Dilleniaceae) leaves has been investigated for the evaluation of antimicrobial and cytotoxic activities. Organic solvent (n-hexane, carbon tetrachloride and chloroform) fractions of methanolic extract and methanolic fraction (aqueous) were screened for their antimicrobial activity by disc diffusion method. Besides, the fractions were screened for cytotoxic activity using brine shrimp (Artemia salina) lethality bioassay. Among the four fractions tested, n-hexane, carbon tetrachloride, and chloroform fractions showed moderate antibacterial and antifungal activity compared to standard antibiotic, kanamycin. The average zone of inhibition was ranged from 6 to 8 mm at a concentration of 400 µg/disc. But the aqueous fraction was found to be insensitive to microbial growth. Compared to vincristine sulfate (with LC(50) of 0.52 µg/ ml), n-hexane and chloroform fractions demonstrated a significant cytotoxic activity (having LC(50) of 1.94 µg/ml and 2.13 µg/ml, respectively). The LC(50) values of the carbon tetrachloride and aqueous fraction were 4.46 µg/ml and 5.13 µg/ ml, respectively. The study confirms the moderate antimicrobial and potent cytotoxic activities of Dillenia indica leaves extract and therefore demands the isolation of active principles and thorough bioassay. PMID:21331191

  3. Evaluation and modeling of the parameters affecting fluoride toxicity level in aquatic environments by bioassay method

    Directory of Open Access Journals (Sweden)

    Hamid Reza Shamsollahi

    2014-04-01

    Full Text Available Background: Fluoride exists in various forms in nature and water resources. , The rising level of fluoride in water resources due to discharge of industrial effluents can cause toxicity in aquatic organisms. To prevent toxicity, it is necessary to determine maximum fluoride toxicity as well as effluent discharge limits. The aim of this study was to determine the maximum fluoride toxicity and the factors affecting fluoride toxicity to provide a model in order to determine the effluent discharge limits. Methods: Daphnia magna bioassay in the absence of confounding factors was used to determine the maximum level of fluoride toxicity. Then, bioassay was repeated in the presence of the confounding factors (hardness, temperature and exposure time to determine their effects. Results: In the absence of intervening factors, fluoride LC50 levels determined after 24, 48 and 72 hours exposure were 4.9, 46.5 and 38.7 mg/l, respectively.. Also, the influence of confounding factors on LC50 values was reported significant by Minitab software. Conclusion: Increasing the water hardness reduced fluoride toxicity, and increasing the water temperature and exposure time increased fluoride toxicity in aquatic environments. Therefore, while determining the wastewater discharge limit in terms of fluoride concentration, it is essential to take the effect of confounding factors on fluoride toxicity into account in order to prevent toxicity in the open water resources.

  4. Dose selection as it pertains to testing a prodrug in carcinogenicity bioassays.

    Science.gov (United States)

    Szczech, G M; Tucker, W E

    1983-01-01

    Toxicologists need more information than is usually available in the early stages of development of a drug in order to choose proper dose levels for testing in the bioassays. The approach most likely to result in successful bioassays involves an early multidisciplinary effort in which there is pharmacokinetic characterization of the test material in both rats and mice. Preliminary 3 month studies are desirable. Periodic sampling of plasma is essential to detect possible non-linear kinetics (as in the example we report herein) reflected as accumulation of the test material or metabolites. This is true regardless of the test substance. However, if one tests prodrugs it may be particularly helpful to know if chemical or enzymatic conversion of the prodrug is linear and if there is reversion to prodrug or other abberant metabolism. Failure to rule out these possibilities could result in subsequent clinically irrelevant organ damage or could compromise longevity or the interpretation of results in lifetime studies. Pharmacokinetic considerations are as valid as the more traditional biologic or morphologic end points used to estimate maximum tolerated or no-effect dose levels. PMID:6681397

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

    Science.gov (United States)

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

    2016-01-01

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

  6. Evaluation of bioassays to monitor surface microlayer toxicity in tropical marine waters.

    Science.gov (United States)

    Rumbold, D G; Snedaker, S C

    1997-02-01

    Bioassays were developed, using embryos of: coral,Montastraea faveolata; graysby, Epinephelus cruentatus;grouper, Epinephelus adscensionis x gruttatus (hybrid); queenconch, Strombus gigas; rock-boring urchin, Echinodermatalucunter; spotted seatrout, Cynoscion nebulosus; variegatedurchin, Lytechinus variegatus; winged pearl oyster, Pteriacolymbus; and yellowtail snapper, Ocyurus chrysurus. Relativesensitivities and precison of various species-endpoint combinations wereevaluated using three reference toxicants: copper, sodium dodecyl sulfate,and Dibrom(R). The 24-h P. colymbus embryo test had the best overallsensitivity and exhibited a high degree of precision. However, oyster embryoswere difficult to obtain and did not aggregate at the air-water interface.Therefore, the P. colymbus embryo test was deemed unsuitable for useas a bioassay for monitoring sea-surface microlayer (SSML) toxicity. Testsbased on normal development of L. variegatus to the early pluteus 3stage and percent normal-live C. nebulosus larvae at 48 h wererelatively sensitive and exhibited good replicability and repeatability. TheL. variegatus urchin embryo test was also found to be highlyreproducible. The results of this comparative study indicated that L.variegatus and C. nebulosus were suitable surrogates forcoral-reef species in toxicity assessments of the SSML. PMID:9069187

  7. Estimation of cytotoxic potency by brine shrimp lethality bioassay application of Clerodendrum infortunatum Linn.

    Institute of Scientific and Technical Information of China (English)

    Talukdar Muhammad Waliullah; Akter MstYeasmin; Ashraful MdAlam; Wahedul Md Islam; Parvez Hassan

    2015-01-01

    Objective: To learn a scientific and systematic knowledge of anticancer, antimicrobial and pharmacological activities of natural products and estimate cytotoxic potency by using ethanol and chloroform extracts of root, leaf and stem of Clerodendrum infortunatum (Verbenaceae) due to its random use in customary and traditional medicine to cure common ailments such as intestinal disorder, diarrhea, tuberculosis and respiratory problems etc. Methods: The in vitro application was carried out with the bench-top bioassay method by using brine shrimp lethality bioassay. Results: All of the crude extracts were found to be lethal and effective. The LC50 value of ethyl alcohol fraction of root was 20.845 mg/L compared to the standard drug tetracycline of 14.675 mg/L to brine shrimp nauplii, indicating that the extracts were biologically active. Conclusions: The cytotoxic study of LC50 value showed that a good correlation with the antibiotic tetracycline. From the comparative correlation error bars and percentage, we understood that ethyl alcohol fraction of root extract was very effective. This study serves as a basis for further research to lead compounds to be isolated so that it may be as a template for the implications of these results for bioactivity and drug discovery potential of herbal products.

  8. Evaluating the performance of the ORTECR DetectiveTM for emergency urine bioassay

    International Nuclear Information System (INIS)

    The performance of the ORTECR DetectiveTM as a field deployable tool for emergency urine bioassay of 137Cs, 60Co, 192Ir, 169Yb and 75Se was evaluated against ANSI N13.30. The tested activity levels represent 10 % RL (reference level) and 1 % RL defined by [Li C., Vlahovich S., Dai X., Richardson R. B., Daka J. N. and Kramer G. H. Requirements for radiation emergency urine bioassay techniques for the public and first responders. Health Phys (in press, 99(5), 702-707 (2010)]. The tests were conducted for both single radionuclide and mixed radionuclides at two geometries, one conventional geometry (CG) and one improved geometry (IG) which improved the MDAs (minimum detectable amounts) by a factor of 1.6-2.7. The most challenging radionuclide was 169Yb. The measurement of the mixture radionuclides for 169Yb at the CG did not satisfy the ANSI N13.30 requirements even at 10 % RL. At 1 % RL, 169Yb and 192Ir were not detectable at either geometry, while the measurement of 60Co in the mixed radionuclides satisfied the ANSI N13.30 requirements only at the IG. (authors)

  9. Comparative study of three oligochaete species as indicators of metals in a sediment toxicity bioassay

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, K.; Scheuerman, P.; Lanza, G.; Nelson, D. [East Tennessee State Univ., Johnson City, TN (United States); Brinkhurst, R. [Aquatic Resources Center, Franklin, TN (United States)

    1995-12-31

    Three oligochaete species, Tubifex tubifex, Branchiura sowerbyi and Lumbriculus variegatus, were analyzed for bioaccumulation and reproductive effects from reference sediment spiked with Cd or Cu. Sediment was spiked using the Sediment Suspension method to achieve concentrations of 4.0, 8.0 and 16.0 mg Cd/kg sediment (dry weight) and 25.0, 36.0, 50.0, 100.0 mg Cu/kg sediment (dry weight) . The bioassay was conducted under aerated, static conditions for 28 d at 22.5 C. Reproductive effects consisting of number of cocoons and eggs produced a negative linear regression with increasing Cd concentration. Cocoon volume remained consistent. Cu was more toxic to T. tubifex in this bioassay than results reported by the USEPA using similar concentrations. Lower concentrations of Cu also showed a negative linear regression with reproductive effects showing that oligochaetes could be a feasible indicator organism for sediment toxicity in a standardized ecological impact assay using reproduction as an endpoint.

  10. Erythropoietin bioassays using fetal mouse liver cells: validations and technical improvements

    International Nuclear Information System (INIS)

    Studies are described which were designed to compare an erythropoietin (Ep) bioassay using the uptake of 125I-deoxyuridine (125-I-UdR) into whole cells cultured in micro-titer plates with an established method where the cells were cultured in 1 ml volumes using the incorporation of 59Fe into heme as the endpoint. The results demonstrate the validity of the substitution of 125I-UdR uptake into whole cells as a replacement for 59Fe incorporation into heme as an assay endpoint and the adaptation of the method to a semi-micro scale with automated cell harvesting. A culture time significantly shorter than 24 h is demonstrated not to be of practical benefit. Two methods are proposed to saturate the growth promoting effects of iron-containing transferrin. The performance of semi-micro, serum-containing bioassay employing untreated serum as the test material is shown to be superior to previous systems for the biological measurement of Ep

  11. Pharmacodynamics of TRPV1 Agonists in a Bioassay Using Human PC-3 Cells

    Directory of Open Access Journals (Sweden)

    Daniel Alvarez-Berdugo

    2014-01-01

    Full Text Available Purpose. TRPV1 is a multimodal channel mainly expressed in sensory neurons. We aimed to explore the pharmacodynamics of the TRPV1 agonists, capsaicin, natural capsaicinoids, and piperine in an in vitro bioassay using human PC-3 cells and to examine desensitization and the effect of the specific antagonist SB366791. Methods. PC-3 cells expressing TRPV1 were incubated with Fluo-4. Fluorescence emission changes following exposition to agonists with and without preincubation with antagonists were assessed and referred to maximal fluorescence following the addition of ionomycin. Concentration-response curves were fitted to the Hill equation. Results. Capsaicin and piperine had similar pharmacodynamics (Emax 204.8 ± 184.3% piperine versus 176.6 ± 35.83% capsaicin, P=0.8814, Hill coefficient 0.70 ± 0.50 piperine versus 1.59 ± 0.86 capsaicin, P=0.3752. In contrast, capsaicinoids had lower Emax (40.99 ± 6.14% capsaicinoids versus 176.6 ± 35.83% capsaicin, P<0.001. All the TRPV1 agonists showed significant desensitization after the second exposition and their effects were strongly inhibited by SB366791. Conclusion. TRPV1 receptor is successfully stimulated by capsaicin, piperine, and natural capsaicinoids. These agonists present desensitization and their effect is significantly reduced by a TRPV1-specific antagonist. In addition, PC-3 cell bioassays proved useful in the study of TRPV1 pharmacodynamics.

  12. 基于克隆表达的芳香烃受体系统的二噁(口英)生物检测方法研究%Construction of the dioxin bioassay method based on the clonal expressed aryl hydrocarbon receptor system

    Institute of Scientific and Technical Information of China (English)

    王卓; 赵娜; 沈钧; 王影; 汤乃军; 吴蕴棠; 张万起; 宓怀风

    2009-01-01

    ) The target genes including AhR-PAS,AhR-C and ARNT-PAS were amplified by RT-PCR by using the total RNA purified from the liver cells of C57BL/6J mice as templates to construct pGEX-5XI recombinants. The recombinant plasmids were expressed in E. coli. (2) The rabbits were immuned by the eional fusion proteins: AhR-PAS, AhR-C to prepare the polyclonal antibody. (3) The natural AhR from the hepatic eytosol of C57BL/6J mice was extracted. The artificial cloning expressed fusion protein: GST-ARNT-PAS and the natural AhR were incubated in different dose of TCDD. The quantity of the heterodimer through affinity adsorption and Western blots were measured. Results (1) The target proteins including AhR-PAS, AhR-C and ARNT-PAS were successfully cloned and expressed in E. coli. (2) The detection limit of polyclonal antibody AhR-PAS and AhR-C were 5 ng and 1 ng,respectively. (3)The total protein concentration prepared from the liver cells was 60.5 mg/ml. The artificial clonal protein ARNT-PAS could specifically bind to the natural AhR complex with the existence of TCDD. The detection limit of TCDD was 0.25 pmol which was 80 pg approximately. Conclusion A TCDD detection method based on the aryl hydrocarbon receptor system was established and the detection limit might reach pg grade.

  13. Functional bioassays for immune monitoring of high-risk neuroblastoma patients treated with ch14.18/CHO anti-GD2 antibody.

    Directory of Open Access Journals (Sweden)

    Nikolai Siebert

    Full Text Available Effective treatment of high-risk neuroblastoma (NB remains a major challenge in pediatric oncology. Human/mouse chimeric monoclonal anti-GD2 antibody (mAb ch14.18 is emerging as a treatment option to improve outcome. After establishing a production process in Chinese hamster ovary (CHO cells, ch14.18/CHO was made available in Europe for clinical trials. Here, we describe validated functional bioassays for the purpose of immune monitoring of these trials and demonstrate GD2-specific immune effector functions of ch14.18/CHO in treated patients. Two calcein-based bioassays for complement-dependent- (CDC and antibody-dependent cellular cytotoxicity (ADCC were set up based on patient serum and immune cells tested against NB cells. For this purpose, we identified LA-N-1 NB cells as best suited within a panel of cell lines. Assay conditions were first established using serum and cells of healthy donors. We found an effector-to-target (E:T cell ratio of 20:1 for PBMC preparations as best suited for GD2-specific ADCC analysis. A simplified method of effector cell preparation by lysis of erythrocytes was evaluated revealing equivalent results at an E:T ratio of 40:1. Optimal results for CDC were found with a serum dilution at 1:8. For validation, both within-assay and inter-assay precision were determined and coefficients of variation (CV were below 20%. Sample quality following storage at room temperature (RT showed that sodium-heparin-anticoagulated blood and serum are stable for 48 h and 96 h, respectively. Application of these bioassays to blood samples of three selected high-risk NB patients treated with ch14.18/CHO (100 mg/m(2 revealed GD2-specific increases in CDC (4.5-9.4 fold and ADCC (4.6-6.0 fold on day 8 compared to baseline, indicating assay applicability for the monitoring of multicenter clinical trials requiring sample shipment at RT for central lab analysis.

  14. In vivo genotoxicity of furan in F344 rats at cancer bioassay doses

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wei, E-mail: Wei.Ding@fda.hhs.gov [Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Petibone, Dayton M. [Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Latendresse, John R. [Toxicologic Pathology Associates, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Pearce, Mason G. [Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Muskhelishvili, Levan; White, Gene A. [Toxicologic Pathology Associates, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Chang, Ching-Wei [Division of Personalized Nutrition and Medicine, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Mittelstaedt, Roberta A.; Shaddock, Joseph G.; McDaniel, Lea P. [Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Doerge, Daniel R. [Division of Biochemical Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States); Morris, Suzanne M.; Bishop, Michelle E.; Manjanatha, Mugimane G.; Aidoo, Anane; Heflich, Robert H. [Division of Genetic and Molecular Toxicology, US FDA/National Center for Toxicological Research, Jefferson, AR 72079 (United States)

    2012-06-01

    Furan, a potent rodent liver carcinogen, is found in many cooked food items and thus represents a human cancer risk. Mechanisms for furan carcinogenicity were investigated in male F344 rats using the in vivo Comet and micronucleus assays, combined with analysis of histopathological and gene expression changes. In addition, formamidopyrimidine DNA glycosylase (Fpg) and endonuclease III (EndoIII)-sensitive DNA damage was monitored as a measure of oxidative DNA damage. Rats were treated by gavage on four consecutive days with 2, 4, and 8 mg/kg bw furan, doses that were tumorigenic in 2-year cancer bioassays, and with two higher doses, 12 and 16 mg/kg. Rats were killed 3 h after the last dose, a time established as producing maximum levels of DNA damage in livers of furan-treated rats. Liver Comet assays indicated that both DNA strand breaks and oxidized purines and pyrimidines increased in a near-linear dose-responsive fashion, with statistically significant increases detected at cancer bioassay doses. No DNA damage was detected in bone marrow, a non-target tissue for cancer, and peripheral blood micronucleus assays were negative. Histopathological evaluation of liver from furan-exposed animals produced evidence of inflammation, single-cell necrosis, apoptosis, and cell proliferation. In addition, genes related to apoptosis, cell-cycle checkpoints, and DNA-repair were expressed at a slightly lower level in the furan-treated livers. Although a mixed mode of action involving direct DNA binding cannot be ruled out, the data suggest that furan induces cancer in rat livers mainly through a secondary genotoxic mechanism involving oxidative stress, accompanied by inflammation, cell proliferation, and toxicity. -- Highlights: ► Furan is a potent rodent liver carcinogen and represents a human cancer risk. ► Furan induces DNA damage in rat liver at cancer bioassay doses. ► Furan induces oxidative stress, inflammation and cell proliferation in rat liver. ► Expression of

  15. [Soil nutrient status of pure birch and larch plantations based on their seedlings bioassay].

    Science.gov (United States)

    Liu, Zhong-ling; Wang, Qing-cheng; Sun, Xin-xin

    2011-08-01

    One-year-old birch (Betula platyphylla) and larch (Larix olgensis) seedlings were respectively planted in pots with the soils taken from 35-year-old pure birch and larch plantations, and the seedlings growth, biomass increment, foliar nutrient content, and soil nutrient status were monitored, aimed to evaluate the fertility levels of the two soils and the possible interspecific interaction in mixed larch-birch forest. Birch soil had significantly higher contents of total N and available N than larch soil, while larch soil had significantly higher contents of total P, available P, and total K than birch soil (P birch seedlings growing on birch soil were 69%, 52%, and 65% (P birch seedlings growing on birch soil was higher than that on larch soil, while the foliar P concentration was higher when the seedlings were growing on larch soil than on birch soil. The birch soil had higher content of available N because of the higher litterfall, while the larch soil had greater available P because of the higher P mobilizing effect. It was predicted that in mixed birch-larch forest, the complementary interaction of soil N and P could benefit the growth of the two tree species.

  16. Disposal of dredged sediments in tropical soils: ecotoxicological evaluation based on bioassays with springtails and enchytraeids.

    Science.gov (United States)

    Cesar, Ricardo; Natal-da-Luz, Tiago; Bidone, Edison; Castilhos, Zuleica; Polivanov, Helena; Sousa, José Paulo

    2015-02-01

    Metal reference values established in Brazilian legislation for terrestrial disposal of dredged sediments and soil quality were derived for temperate regions. To evaluate the adequacy of such metal reference values to tropical soils, the ecotoxicity of a dredged sediment (from the Guanabara bay, Rio de Janeiro, Brazil) was investigated in two local soils (ferralsol and chernosol) by performing avoidance and reproduction tests using Folsomia candida and Enchytraeus crypticus. Test doses consisted of 0 %, 1.25 %, 2.5 %, 5, 10 %, and 20 %. Total and potentially bioavailable metal concentrations were determined in the test mixtures. Although the chernosol mixtures had the highest total metal concentrations, the influence of the expansive clay minerals (with high ability to adsorb metals) and the high contents of nutrients typical from this type of soils, seem to reduce the ecotoxicity. Collembolan avoidance behavior was the least sensitive endpoint. The lowest sediment doses increased the reproduction of F. candida in ferralsol mixtures. E. crypticus reproduction in the ferralsol mixtures were more pronounced at lower concentrations than in chernosol mixtures. Possibly the low nutrient content of the ferralsols, in connection with the addition of small amounts of sediment, created particular conditions that promoted reproduction of the test species. Data obtained in the ecotoxicological tests may support the establishment of a "safe" ecological dose of dredged sediments to be applied in tropical soils, supporting decision-makers in programs of environmental management. PMID:25223356

  17. Multi-scale magnetic nanoparticle based optomagnetic bioassay for sensitive DNA and bacteria detection

    DEFF Research Database (Denmark)

    Tian, Bo; Zardán Gómez De La Torre, Teresa; Donolato, Marco;

    2016-01-01

    nanoparticles (binding to the target) and thus the optomagnetic response of the sample, which is measured by an optomagnetic setup including a 405 nm laser and a photodetector. The limit of detection is mainly set by the lowest measurable concentration of magnetic nanoparticles. Herein, as new results compared...

  18. A chromosomally based luminescent bioassay for mercury detection in red soil of China

    Energy Technology Data Exchange (ETDEWEB)

    Wei, He [Chinese Academy of Sciences, Nanking (China). State Key Lab. of Soil and Sustainable Agriculture; Nanjing Normal Univ., Nanking (China). College of Life Science; Cheng, Han; Ting, Mao; Zhong, Wen-Hui [Nanjing Normal Univ., Nanking (China). College of Chemistry and Environmental Science; Lin, Xian-Gui [Chinese Academy of Sciences, Nanking (China). State Key Lab. of Soil and Sustainable Agriculture

    2010-07-15

    A luminescent reporter gene system was constructed by fusing the mercury-inducible promoter, P{sub merT}, and its regulatory gene, merR, with a promoterless reporter gene EGFP. A stable and nonantibiotic whole-cell reporter (BMB-ME) was created by introducing the system cassette into the chromosome of Pseudomonas putida strain and then applied it for mercury detection in the red soil of China. Spiked with 10 and 100 {mu}g g{sup -1} Hg{sup 2+} and after 15 and 30 days incubation, soil samples were extracted and evaluated water soluble, bioavailable, organic matter bound, and residual fractions of mercury by both BMB-ME and chemical way. The expression of EGFP was confirmed in soil extraction, and fluorescence intensity was quantified by luminescence spectrometer. The sensor strain BMB-ME appeared to have a detection range similar to that of reversed-phase high-performance liquid chromatography method. The optimal temperature for EGFP expression was 35 C and the lowest detectable concentration of Hg{sup 2+} 200 nM. Cu{sup 2+}, Fe{sup 2+}, Mn{sup 2+}, Sn{sup 2+}, Zn{sup 2+}, Co{sup 2+}, Ag{sup +}, Ba{sup 2+}, Mg{sup 2+}, and Pb{sup 2+} ions at nanomolar level did not interfere with the measurement. These results showed that the BMB-ME constitute an adaptable system for easy sensing of small amounts of mercury in the red soil of China. (orig.)

  19. A bioassay based on recombinant DNA technology for determining selenium concentration.

    OpenAIRE

    Reches, M; Zhao, C; Engelberg-Kulka, H

    1994-01-01

    The trace element selenium has recently attracted attention, particularly because (i) selenocysteine is involved in the active site of various prokaryotic and eukaryotic enzymes, some of which have a role in human health; (ii) selenocysteine incorporation into these proteins is coded by UGA codons; and (iii) as a result, selenocysteine is now considered to be the 21st amino acid in an expanded genetic code. Here, we built recombinant DNA constructs in which expression of the lac'Z gene is dri...

  20. Evaluation of wastewater reclamation technologies based on in vitro and in vivo bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Cao Nan [SKLEAC, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)], E-mail: greenerspan@yahoo.com.cn; Yang Min [SKLEAC, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)], E-mail: yangmin@rcees.ac.cn; Zhang Yu [SKLEAC, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)], E-mail: zhangyu@rcees.ac.cn; Hu Jianying [College of Urban and Environmental Science, Peking University, Beijing 100871 (China)], E-mail: hujy@urban.pku.edu.cn; Ike, Michihiko [Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: ike@see.eng.osaka-u.ac.jp; Hirotsuji, Junji [Mitsubishi Electric Corporation Advanced Technology R and D Center, Amagasaki-Hyogo 661-8661 (Japan)], E-mail: hirotsuji@china.meap.com; Matsui, Hisae [Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Mitsubishi Electric Corporation Advanced Technology R and D Center, Amagasaki-Hyogo 661-8661 (Japan)], E-mail: Matsui.Hisae@ap.MitsubishiElectric.co.jp; Inoue, Daisuke [Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: inoue@wb.see.eng.osaka-u.ac.jp; Sei, Kazunari [Division of Sustainable Energy and Environmental Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan)], E-mail: sei@see.eng.osaka-u.ac.jp

    2009-02-15

    When municipal secondary effluent is used as the main supplementation water source for surface water bodies, its potential adverse ecological effects should not be neglected. The objective of this work was to investigate the effectiveness of several technologies, i.e. combination of coagulation and sand filtration (CSF), ultraviolet (UV) irradiation, chlorination, ozonation, ultrafiltration (UF) and reverse osmosis filtration (RO), on the removal of acute ecotoxicity, genotoxicity and retinoic acid receptor (RAR) agonist activity from the municipal secondary effluent. The effects of treated effluents on the development of Japanese medaka (Oryzias latipes) embryos were also evaluated. The secondary effluent exhibited a mutagenic effect on Salmonella typhimurium strain TA 1535/pSK1002, acute invertebrate toxicity to Daphnia magna, and weak RAR {alpha} activity. RO and ozonation demonstrated remarkable removals of the genotoxic effect, acute toxicity and RAR activity from secondary effluent, while chlorination could elevate both genotoxicity and acute toxicity. CSF, UV, UF, chlorination as well as RO could decrease the 4-day mortality of medaka embryos and accordingly increase the hatching success rate, comparing with the secondary effluent. Ozonation at 4 mg/l and higher doses, however, elicited significantly higher 4-day mortality, leading to the reduction of the hatching success rate.

  1. SERMs and SARMs: Detection of their activities with yeast based bioassays

    NARCIS (Netherlands)

    Bovee, T.F.H.; Thevis, M.; Hamers, A.R.M.; Peijnenburg, A.A.C.M.; Nielen, M.W.F.; Schoonen, W.G.E.J.

    2010-01-01

    Selective estrogen receptor modulators (SERMs) and selective androgen receptor modulators (SARMs) are compounds that activate their cognate receptor in particular target tissues without affecting other organs. Many of these compounds will find their use in therapeutic treatments. However, they also

  2. Rapid, Bioassay-Guided Process for the Detection and Identification of Antibacterial Neem Oil Compounds.

    Science.gov (United States)

    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. PMID:26951543

  3. Occupational program monitoring in Uranium Concentrate Unity at Caetite (URA) - Bahia State, Brazil: bioassay program

    International Nuclear Information System (INIS)

    The principal aim of bioassay monitoring program in Uranium Concentrate Unity, URA, in Caetite is the maintenance of acceptably safe and satisfactory working conditions, according to national and international norms. Specifically, the objective is to interpret measurements in terms of intake of uranium and committed effective dose, so that the results can be used to demonstrate compliance with the system of dose limitation and, mainly, the optimization of radiation protection. The employed technique is the measurement of uranium in excreta from workers in mine, crushing and uranium concentrate production areas. In conclusion, workers from mining and crushing areas should be monitored by the routine program; urine and feces samples should be analyzed by mass spectrometry, with ICP-MS. The operational monitoring program should be carried out in workers from uranium concentrate production area; urine and feces samples should be analyzed by less expensive techniques. (author)

  4. Symposium on Short-Term Genetic Bioassays in the Evaluation of Complex Environmental Mixtures

    CERN Document Server

    Sandhu, Shahbeg; Lewtas, Joellen; Claxton, Larry; Strauss, Gary; Nesnow, Stephen

    1985-01-01

    With this proceedings of the fourth symposium on complex mixtures, we continue to revise and extend our knowledge of genetic methods for the evaluation of chemical mixtures in the environment. The early chapters of this volume are devoted to new bioassay techniques that are directly applicable to the monitoring of environments contaminated with genotoxic chemicals. Microbiological methods have been further refined to meet the special needs of atmospheric monitoring so that very small samples may now be efficiently tested. New in situ methods utilizing green plants actually avoid many of the usual difficulties of sample collection and preparation and offer special advantages in monitoring wastewater, sludges, and hazardous wastes. Insects also are being employed very effectively in the evaluation of gaseous air pollutants in controlled laboratory investigations. Increased emphasis has been placed on a comprehensive assessment of the potential of complex mixtures t9 cause various kinds of genetic damage. New as...

  5. Harvester ant bioassay for assessing hazardous chemical waste sites. [Pogonomyrmex owhyeei

    Energy Technology Data Exchange (ETDEWEB)

    Gano, K.A.; Carlile, D.W.; Rogers, L.E.

    1985-05-01

    A technique was developed for using harvester ants, Pogonomyrmex owhyeei, in terrestrial bioassays. Procedures were developed for maintaining stock populations, handling ants, and exposing ants to toxic materials. Relative toxicities were determined by exposing ants to 10 different materials. These materials included three insecticides, Endrin, Aldrin, and Dieldrin; one herbicide, 2,4-D; three complex industrial waste residuals, wood preservative sludge, drilling fluid, and slop oil; and three heavy metals, copper zinc, and cadium. Ants were exposed in petri dishes containing soil amended with a particular toxicant. Under these test conditions, ants showed no sensitivity to the metals or 2,4-D. Ants were sensitive to the insecticides and oils in repeated tests, and relative toxicity remained consistent throughout. Aldrin was the most toxic material followed by Dieldrin, Endrin, wood preservative sludge, drilling fluid, and slop oil. 12 refs., 2 figs., 2 tabs.

  6. CYTOTOXIC (BRINE SHRIMP LETHALITY BIOASSAY AND ANTIOXIDANT INVESTIGATION OF BARRINGTONIA ACUTANGULA (L.”

    Directory of Open Access Journals (Sweden)

    Md. Asaduzzaman

    2015-08-01

    Full Text Available Barringtonia acutangula (L. gaertn. (Family: Barringtoniaceae, a medicinal small to medium evergreen tree known as ‘Hijal’, is used in diarrhoea, dysentery, colic, flatulence, cooling, aperients expectorant, stimulating emetic, astringents to the bowel, antihelminthic, bronchitis, lumber pain, hallucinations, seminal weakness, gonorrhoea and many other ailments in rural areas of Bangladesh It is also used as traditional medicine in other countries. But till to date, sporadic attempts have been made for the scientific and methodical validation of these traditional claims. In Brine Shrimp Lethality Bioassay, all the extracts produced dose dependent cytotoxicity effect to brine shrimp nauplii with methanol extract of leaf exhibiting highest toxicity having LC50 value 46.24 μg/ml where standard vincristine sulphate had the LC50 value of 0.69 μg/ml. & In antioxidant attempt by reducing power and CUPRAC assays, pet. ether extract of leaf were found to exhibit moderate but concentration dependent reducing power respectively.

  7. Stability of the intra- and extracellular toxins of Prymnesium parvum using a microalgal bioassay

    DEFF Research Database (Denmark)

    Blossom, Hannah Eva; Andersen, Nikolaj Gedsted; Rasmussen, Silas Anselm;

    2014-01-01

    Prymnesium parvum produces a variety of toxic compounds, which affect other algae, grazers and organisms at higher trophic levels. Here we provide the method for development of a sensitive algal bioassay using a microalgal target, Teleaulax acuta, to measure strain variability in P. parvum toxicity......, as well as the temporal stability of both the intracellular and the extracellular lytic compounds of P. parvum. We show high strain variation in toxicities after 3h incubation with LC50s ranging from 24 to 223×103cellsml−1. Most importantly we prove the necessity of testing physico-chemical properties...... of P. parvum toxins before attempting to isolate and characterize them. The extracellular toxin in the supernatant is highly unstable, and it loses significant lytic effects after 3 days despite storage at −20°C and after only 24h stored at 4°C. However, when stored at −80°C, lytic activity is more...

  8. Theobroma cacao: Review of the Extraction, Isolation, and Bioassay of Its Potential Anti-cancer Compounds.

    Science.gov (United States)

    Baharum, Zainal; Akim, Abdah Md; Hin, Taufiq Yap Yun; Hamid, Roslida Abdul; Kasran, Rosmin

    2016-02-01

    Plants have been a good source of therapeutic agents for thousands of years; an impressive number of modern drugs used for treating human diseases are derived from natural sources. The Theobroma cacao tree, or cocoa, has recently garnered increasing attention and become the subject of research due to its antioxidant properties, which are related to potential anti-cancer effects. In the past few years, identifying and developing active compounds or extracts from the cocoa bean that might exert anti-cancer effects have become an important area of health- and biomedicine-related research. This review provides an updated overview of T. cacao in terms of its potential anti-cancer compounds and their extraction, in vitro bioassay, purification, and identification. This article also discusses the advantages and disadvantages of the techniques described and reviews the processes for future perspectives of analytical methods from the viewpoint of anti-cancer compound discovery. PMID:27019680

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

    Science.gov (United States)

    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. PMID:22445389

  10. Acute toxicity bioassay with native plants to evaluate an oil spill

    Directory of Open Access Journals (Sweden)

    Vivien Pentreath

    2015-06-01

    Full Text Available Plant bioassays are excellent tools for the evaluation of environmental risks. In particular the use of seeds of vascular plants is recommended due to their higher sensitivity. The aim of this study was to evaluate the behavior of native plants in order for them to be used as biological indicators of environmental oil pollution in relation to a standardized bioindicator. We analyzed the germination index (GI of Lactuca sativa L., Atriplex lampa (Moq. D.Dietri. and Prosopis denudans in thirty soil samples taken from an oil field to detect phytotoxic effects. GI, is a cheap, fast and reproducible biological method for determining the toxicity of the soil, thus helping to characterize areas with contaminated soils. The results show that, after germination, Atriplex lampa (Moq. D.Dietri. and Prosopis denudans are more resistant in the contaminated soils of an oil field than the reference bioindicator (Lactuca sativa L..

  11. Respiratory tract clearance model for dosimetry and bioassay of inhaled radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, M.R.; Birchall, A. (National Radiological Protection Board, Chilton (UK)); Cuddihy, R.G. (Inhalation Toxicology Research Inst., Albuquerque, NM (USA)); James, A.C. (Pacific Northwest Lab., Richland, WA (USA)); Roy, M. (CEA Centre d' Etudes Nucleaires de Fontenay-aux-Roses, 92 (France). Inst. de Protection et de Surete Nucleaire)

    1990-07-01

    The ICRP Task Group on Respiratory Tract Models is developing a model to describe the retention and clearance of deposited radionuclides for dose-intake calculations and interpretation of bioassay data. Clearance from each region is treated as competition between mechanical transport, which moves particles to the gastro-intestinal tract and lymph nodes, and the translocation of material to blood. It is assumed that mechanical transport rates are the same for all materials, and that rates of translocation to blood are the same in all regions. Time-dependent clearance is represented by combinations of compartments. Representative values of parameters to describe mechanical transport from the human respiratory tract have been estimated, and guidance is given on the determination of translocation rates. It is emphasized that the current version of the model described here is still provisional. 30 refs.

  12. A Bioassay Technique to Study Clomazone Residues in Sandy Loam Soil

    Directory of Open Access Journals (Sweden)

    Jelena Gajić Umiljendić

    2013-01-01

    Full Text Available A bioassay test was conducted to evaluate the sensitivity of maize, sunflower and barley toclomazone residues in sandy loam soil. Clomazone was applied at different rates from 0.12 to12 mg a.i./kg of soil. The parameters measured 14 days after treatment were: shoot height, freshand dry weight, and content of pigments (carotenoids, chlorophyll a and chlorophyll b. Theresults showed that the lowest clomazone concentration caused a significant reduction in allmeasured parameters for barley and sunflower shoots. Fresh weight of maize shoots was notsensitive to clomazone residual activity in soil while the other parameters were highly inhibited.Nomenclature: clomazone (2-(2-chlorbenzyl-4,4-dimethyl-1,2-oxazolidin-3-one, maize(Zea mays L., sunflower (Helianthus annuus L., barley (Hordeum vulgare L.

  13. Isolation of bioactive allelochemicals from sunflower (variety Suncross-42) through fractionation-guided bioassays.

    Science.gov (United States)

    Anjum, Tehmina; Bajwa, Rukhsana

    2010-11-01

    Plants are rich source of biologically active allelochemicals. However, natural product discovery is not an easy task. Many problems encountered during this laborious practice can be overcome through the modification of preliminary trials. Bioassay-directed isolation of active plant compounds can increase efficiency by eliminating many of the problems encountered. This strategy avoids unnecessary compounds, concentrating on potential components and thus reducing the cost and time required. In this study, a crude aqueous extract of sunflower leaves was fractionated through high performance liquid chromatography. The isolated fractions were checked against Chenopodium album and Rumex dentatus. The fraction found active against two selected weeds was re-fractionated, and the active components were checked for their composition. Thin layer chromatography isolated a range of phenolics, whereas the presence of bioactive terpenoids was confirmed through mass spectroscopy and nuclear magnetic resonance spectroscopy. PMID:20981619

  14. Effect of external agent on chemiluminescence in bioassay sample - a study

    International Nuclear Information System (INIS)

    Tritium is one of the important radio nuclide contributing about 30-35% of collective dose through internal exposure of plant personnel in Indian PHWRs. Internal dose is monitored by bioassay using liquid scintillation analyzer. There are some external agents that interfere with the tritium counting in urine sample of individuals. These external agents give rise to chemiluminescence in the sample, which may result in wrong interpretation of the counting rates. One such case was studied at Rajasthan Atomic Power Station (RAPS)-3 and 4 in which urine sample of an individual indicated significantly high uptake of tritium whereas the person was not involved in any radioactive job. Investigation revealed that counts due to the sample were caused by chemiluminescence in the urine sample because of homeopathic drug, which the person was taking. (author)

  15. Rapid, Bioassay-Guided Process for the Detection and Identification of Antibacterial Neem Oil Compounds.

    Science.gov (United States)

    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.

  16. Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study.

    Science.gov (United States)

    Dai, Chao-Fan; Tian, De-Ying; Li, Shu-Ping; Li, Xiao-Dong

    2015-12-01

    Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells. PMID:26354264

  17. [Bioassay on oviposition repellency of non-preferable plant extracts against citrus red mite Panonychus citri].

    Science.gov (United States)

    Cen, Yijing; Pang, Xiongfei; Zhou, Qiong; Peng, Yuefeng; Xu, Changbao

    2004-09-01

    The oviposition repellency of the alcohol extracts from 50 species of non-preferable plants and azadirachtin against citrus red mite (Panonychus citri) was determined using laboratory bioassays. In choice tests, the extracts from 42 of the 50 plant species and 1% azadirachtin (2000 x) significantly reduced oviposition 1d after treatment. The repellency effect of the extracts from the 42 plant species was better than that of azadirachtin. Mikania micrantha extract had the best result, with an Interference Index of Population Control (IIPC) of 0.087 1 d after treatment, and significantly reduced oviposition for 9 d, while the extracts from Sesbania cannabina, Allium tuberosum, Paederia scandens, Duranta erecta and Dicranopteris pedata also had good effects, with an oviposition repellency of over 70% 1 d after treatment, and significantly reduced oviposition for 4-6 d. The effect became weaker as time went on. None of the extracts showed significant oviposition attraction. PMID:15669510

  18. Robust Discrimination between Single Gold Nanoparticles and Their Dimers in Aqueous Solution for Ultrasensitive Homogeneous Bioassays

    Directory of Open Access Journals (Sweden)

    Jun Kobayashi

    2015-01-01

    Full Text Available We propose a robust method to distinguish isolated single gold nanoparticles (AuNP monomers and their dimers under Brownian motion, a key for ultrasensitive homogeneous bioassays, including AuNP sandwich assays. To detect dimers and distinguish them from a larger number of monomers in aqueous solution, single-particle polarization microscopy was performed. For the accurate detection of individual particles, the optical anisotropy and rotational diffusion time are measured because a dimer is much more anisotropic than the nearly spherical monomer and the rotational diffusion time of a dimer is four times that of a monomer. By employing an autocorrelation analysis, we defined a measure of distinguishing that simultaneously enables high detection probability and low error probability. The detection platform offers homogeneous DNA hybridization assays and immunoassays at the subpicomolar level.

  19. ICP-MS: Answer to Challenges of Bioassay Monitoring of Occupationally Workers for Thorium and Uranium

    International Nuclear Information System (INIS)

    The application of bioassay monitoring to assess the internal radiation dose to subjects exposed to elevated levels of thorium (Th), uranium (U) and their related compounds from the working environment require the precise measurement of the annual increments of daily urinary excretion over and above the previous year's excretion rate. At GSF Research Center for Environment and Health (Germany), a highly sensitive and precise analytical method was developed using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to measure extremely low concentrations of Th and U in urine. Using this method, the minimum limits of determination (LOD) of 1 ng/L for both radionuclides could be achieved. At the concentration range between 15-25 ng/L, the precision is better that 10%. The details of the method and its applications are discussed here. (Author) 3 refs

  20. Effects of Direct and Indirect Exposure of Insecticides to Garden Symphylan (Symphyla: Scutigerellidae) in Laboratory Bioassays.

    Science.gov (United States)

    Joseph, Shimat V

    2015-12-01

    The garden symphylan, Scutigerella immaculata Newport, is a serious soil pest whose root feeding affects yield and survival of several high valued crops in the California's central coast. Because organophosphate insecticides, widely used for S. immaculata control, are rigorously regulated and little is known about the efficacy of alternate insecticides, laboratory bioassays were conducted to determine insecticide efficacy through repellency and lethality. To determine indirect repellency (noncontact) of insecticides, choice assays were conducted where five S. immaculata were introduced into the arena to choose between insecticide-treated and untreated wells whereas, in direct repellency (contact) assays, three insecticide-treated 1-cm-diameter discs were pasted into the arena and the number of visits, time spent per visitation, and number of long-duration (>10 s) stays of five S. immaculata were quantified. To determine efficacy through direct mortality, number of S. immaculata died after 72 h were determined by introducing 10 S. immaculata to insecticide-treated soil assays. In indirect exposure bioassays, seven (clothianidin, oxamyl, zeta-cypermethrin, chlorpyrifos, ethoprop, azadirachtin, and a combination of beta-cyfluthrin and imidacloprid) out of 14 insecticides tested elicited repellency to S. immaculata. Of six insecticides tested in the direct exposure assays, only tolfenpyrad elicited contact repellency. In soil assays, after 72 h of introduction, bifenthrin, oxamyl, clothianidin, zeta-cypermethrin, and tolfenpyrad caused 100, 95, 80, 44, and 44% S. immaculata mortality, respectively, which was significantly greater than distilled water and four other insecticides. The implications of these results on S. immaculata management in the California's central coast are discussed. PMID:26470373

  1. A miniature bioassay for testing the acute phytotoxicity of photosystem II herbicides on seagrass.

    Directory of Open Access Journals (Sweden)

    Adam D Wilkinson

    Full Text Available 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/F(m' was highest and no deterioration of photosystems was evident in control leaves. The inhibition of ∆F/F(m' 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.

  2. Validation of a recombinant cell bioassay for the detection of (gluco)corticosteroids in feed.

    Science.gov (United States)

    Bovee, Toine F H; Heskamp, Henri H; Helsdingen, Richard J R; Hamers, Astrid R M; Brouwer, Bram A; Nielen, Michel W F

    2013-01-01

    Use of hormones for fattening purposes is forbidden in the animal production in Europe (European Commission. 1996. Council Directive EC/96/22 (replacement of 88/146/EC). Off J Eur Commun. L125:3-9; European Commission. 1996. Council Directive EC/96/23. Off J Eur Commun. L125:10-32). Moreover, Regulation (EC) 178/2002 (European Commission. 2002. Regulation EC No 178/2002. Off J Eur Commun. L31:1-24) and Regulation (EC) 882/2004 (European Commission. 2004. Regulation EC No 882/2004. Off J Eur Commun. L165:1-135) oblige the member states to identify emerging risks and use validated and accredited methods for control analysis. Only combinations of bioassay activity screening with chemical identification are suited to uphold all laws. No such combination is described for the detection of (gluco)corticoids. In the present study, the GR-CALUX bioassay was validated as a qualitative screening method for the determination of glucocorticoid activity in feed. This validation was performed according to EC Decision 2002/657/EC (European Commission. 2002. Commission Decision 2002/657/EC from Directive 96/23. Off J Eur Commun. L221:8-36). Twenty-two representative blank feed samples were selected and spiked with 50 ng g(-1) of dexamethasone, 100 ng g(-1) of betamethasone or 500 ng g(-1) of triamcinolone. All blank and spiked feed samples fulfilled the CCα and CCβ criteria; the method was specific and robust and glucocorticoids in feed were stable for at least 88 days.

  3. Effects of Direct and Indirect Exposure of Insecticides to Garden Symphylan (Symphyla: Scutigerellidae) in Laboratory Bioassays.

    Science.gov (United States)

    Joseph, Shimat V

    2015-12-01

    The garden symphylan, Scutigerella immaculata Newport, is a serious soil pest whose root feeding affects yield and survival of several high valued crops in the California's central coast. Because organophosphate insecticides, widely used for S. immaculata control, are rigorously regulated and little is known about the efficacy of alternate insecticides, laboratory bioassays were conducted to determine insecticide efficacy through repellency and lethality. To determine indirect repellency (noncontact) of insecticides, choice assays were conducted where five S. immaculata were introduced into the arena to choose between insecticide-treated and untreated wells whereas, in direct repellency (contact) assays, three insecticide-treated 1-cm-diameter discs were pasted into the arena and the number of visits, time spent per visitation, and number of long-duration (>10 s) stays of five S. immaculata were quantified. To determine efficacy through direct mortality, number of S. immaculata died after 72 h were determined by introducing 10 S. immaculata to insecticide-treated soil assays. In indirect exposure bioassays, seven (clothianidin, oxamyl, zeta-cypermethrin, chlorpyrifos, ethoprop, azadirachtin, and a combination of beta-cyfluthrin and imidacloprid) out of 14 insecticides tested elicited repellency to S. immaculata. Of six insecticides tested in the direct exposure assays, only tolfenpyrad elicited contact repellency. In soil assays, after 72 h of introduction, bifenthrin, oxamyl, clothianidin, zeta-cypermethrin, and tolfenpyrad caused 100, 95, 80, 44, and 44% S. immaculata mortality, respectively, which was significantly greater than distilled water and four other insecticides. The implications of these results on S. immaculata management in the California's central coast are discussed.

  4. Importance of REP values when comparing the CALUX bioassay results with chemoanalyses results: Example with spiked vegetable oils

    NARCIS (Netherlands)

    Carbonnelle, S.; Loco, van J.; Overmeire, van I.; Windal, I.; Wouwe, N.; Leeuwen, van S.P.J.

    2004-01-01

    Differences between chemical activated luciferase gene expression (CALUX) bioassay and chemoanalyses results are observed. This paper shows that calculations of the TEQ values using REP values instead of WHO TEF values give different results. The REP values do affect the results obtained by the CALU

  5. Evaluation of the toxic effects of arsenite, chromate, cadmium, and copper using a battery of four bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Kyung-Seok; Lee, Pyeong-Koo [Korea Institute of Geoscience and Mineral Resources (KIGAM), Daejeon (Korea, Republic of). Geologic Environment Div.; Kong, In Chul [Yeungnam Univ., Kyungbuk (Korea, Republic of). Dept. of Environmental Engineering

    2012-09-15

    The sensitivities of four different kinds of bioassays to the toxicities of arsenite, chromate, cadmium, and copper were compared. The different bioassays exhibited different sensitivities, i.e., they responded to different levels of toxicity of each of the different metals. However, with the exception of the {alpha}-glucosidase enzyme activity, arsenite was the most toxic compound towards all the tested organisms, exhibiting the highest toxic effect on the seeds of Lactuca, with an EC{sub 50} value of 0.63 mg/L. The sensitivities of Lactuca and Raphanus were greater than the sensitivities of two other kinds of seeds tested. Therefore, these were the seeds appropriate for use in a seed germination assay. A high revertant mutagenic ratio (5:1) of Salmonella typhimurium was observed with an arsenite concentration of 0.1 {mu}g/plate, indicative of a high possibility of mutagenicity. These different results suggested that a battery of bioassays, rather than one bioassay alone, is needed as a more accurate and better tool for the bioassessment of environmental pollutants. (orig.)

  6. USE OF PLANT AND EARTHWORM BIOASSAYS TO EVALUATE REMEDIATION OF SOIL FROM A SITE CONTAMINATED WITH POLYCHLORINATED BIPHENYLS

    Science.gov (United States)

    Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The ...

  7. Development, optimization and validation of a rapid colorimetric microplate bioassay for neomycin sulfate in pharmaceutical drug products.

    Science.gov (United States)

    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.

  8. Elemol and Amyris Oil Repel the Ticks Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) in Laboratory Bioassays

    Science.gov (United States)

    The essential oil from Amyris balsamifera (Rutaceae) and elemol, a principal constituent of the essential oil of Osage orange, Maclura pomifera (Moraceae) were evaluated in in vitro and in vivo laboratory bioassays for repellent activity against host-seeking nymphs of the blacklegged tick, Ixodes sc...

  9. Sensitivity bioassays of the Cnesterodon decemmaculatus and Pimephales promelasin a series of samples of effluent and reference toxicant

    Directory of Open Access Journals (Sweden)

    Gustavo Saona

    2015-12-01

    Full Text Available This study compared the toxicological sensitivity quantified by the 50% lethal dose of acute toxicity bioassays of Cnesterodon decemmaculatusand Pimephales promelasin benchmark exposure to toxic industrial effluents, wastewater effluents and reference toxicants. At the same time, the toxicological sensitivity of C. decemmaculatusrelated to the size was assayed. Both species were analyzed with 16 bioassays mated by the same substance or compound and a good agreement rL= 0.75 was observed. No significant differences in the overall analysis for effluents and potassium dichromate appeared in toxicological analysis of sensitivity to size. In contrast, significant difference in sensitivity was observed in assays with sodium dodecyl sulfate. Previous studies of the acute bioassays of C. decemmaculatusas well as the results obtained in this work accredit the use of this species in the ecotoxicological evaluation.This work contributes to generate specific ecotoxicological tools employing a native species (C. decemmaculatus and provides comparative information with an internationally accepted species used in reference bioassays (P. promelas. Progress of these studies as a priority research area will contribute to consolidate analytical tools, to develop professional skills and to strengthen institutions that manage the water resources in Uruguay.

  10. DUCKWEED (LEMNA GIBBA) GROWTH INHIBITION BIOASSAYS FOR EVALUATING THE TOXICITY OF OLIVE MILL WASTES BEFORE AND DURING COMPOSTING

    Science.gov (United States)

    Two-phase olive mill waste (TPOMW) is considered a major problem confronting the modern oil extraction and processing industry. Composting has been recently proposed as a suitable method to treat TPOMW so that it is suitable for use in agriculture. In the work reported here, the Lemna gibba bioassay...

  11. Long-Distance Signaling in bypass1 Mutants:Bioassay Development Reveals the bps Signal to Be a Metabolite

    Institute of Scientific and Technical Information of China (English)

    Emma Adhikari; Dong-Keun Lee; Patrick Giavalisco; Leslie E. Sieburth

    2013-01-01

    Root-to-shoot signaling is used by plants to coordinate shoot development with the conditions experienced by the roots.A mobile and biologically active compound,the bps signal,is over-produced in roots of an Arabidopsis thaliana mutant called bypass1 (bps1),and might also be a normally produced signaling molecule in wild-type plants.Our goal is to identify the bps signal chemically,which will then allow us to assess its production in normal plants.To identify any signaling molecule,a bioassay is required,and here we describe the development of a robust,simple,and quantitative bioassay for the bps signal.The developed bioassay follows the growth-reducing activity of the bps signal using the pCYCB1;1::GUS cell cycle marker.Wild-type plants carrying this marker,and provided the bps signal through either grafts or metabolite extracts,showed reduced cell division.By contrast,control grafts and treatment with control extracts showed no change in pCYCB1;1::GUS expression.To determine the chemical nature of the bps signal,extracts were treated with RNase A,Proteinase K,or heat.None of these treatments diminished the activity of bps1 extracts,suggesting that the active molecule might be a metabolite.This bioassay will be useful for future biochemical fractionation and analysis directed toward bps signal identification.

  12. Using macroalgal δ15N bioassay to detect cruise ship waste water effluent inputs in Skagway, AK

    Science.gov (United States)

    Nitrogen stable isotopes are a powerful tool for tracking sources of N to marine ecosystems. I used green macroalgae as a bioassay organism to evaluate if the δ15N signature of cruise ship waste water effluent (CSWWE) could be detected in Skagway Harbor, AK. Opportunistic green...

  13. Assessment of N and P in organic fertilizer using the missing element technique and a microbial bioassay

    International Nuclear Information System (INIS)

    Assessment of N and P in organic fertilizers using the missing element technique and a microbial bioassay.Through a greenhouse bioassay, using sorghum (Sorghum vulgare) as a test plant, and a microbial assay the availability of N and P in 6 substrates was determined, namely: soil alone and in combination with several organic amendments 10% W/W of chicken manure (CM), compost (C), bocashi (B), vermicompost (V) and coffe hulls (Br). In the microbial assay a complete randomized design with 6 replicates was used; the microbial biomass (BM) was determined 2 days after the glucose amendment of each treatment. In both bioassays a 2 X 2 factorial (N and P fertilization) was establish and the following combinations resulted: +N, +P, +P+N and -P-N (control). For the greenhouse experiment, a complete randomized design with 4 replicates was used. Above-ground plant material of sorghum was harvested 34 days after showing to determine plant dry weight (PS) and content of N and P. Both assays showed a response to the soil amendment with N and P. Soil treatments with CM, C and B showed the highest values of PS and BM. Soil treatment with CM amended with N, P or both did not showed a response in PS or BM, in C and B there was a response to N addition but not to P. In treatments with V and Br, the lowest values for PS and BM were obtained, and there was a growth response to N and P. Both bioassays were able to pinpoint N and P defficiencies in the soil as well in some of the mixtures of soil with organic amendments. A high correlation was encountered between the greenhouse assay and the microbial bioassay (r= 0.86, P=0.0001). Therefore, the microbial bioassay can be a cheaper alternative to the plant bioassay not only to evaluate the nutritional quality of compost but also to identify nutrient deficiencies in soils as well as in substrates amended with organic fertilizers. (Author)

  14. Low cost quantitative digital imaging as an alternative to qualitative in vivo bioassays for analysis of active aflatoxin B1.

    Science.gov (United States)

    Rasooly, Reuven; Do, Paula M; Hernlem, Bradley J

    2016-06-15

    Aflatoxin B1 (AFB1) producing fungi contaminate food and feed and are a major health concern. To minimize the sources and incidence of AFB1 illness there is a need to develop affordable, sensitive mobile devices for detection of active AFB1. In the present study we used a low cost fluorescence detector and describe two quantitative assays for detection of detoxified and active AFB1 demonstrating that AFB1 concentration can be measured as intensity of fluorescence. When the assay plate containing increasing concentrations of AFB1 is illuminated with a 366 nm ultraviolet lamp, AFB1 molecules absorb photons and emit blue light with peak wavelength of 432 nm. The fluorescence intensity increased in dose dependent manner. However, this method cannot distinguish between active AFB1 which poses a threat to health, and the detoxified AFB1 which exhibits no toxicity. To measure the toxin activity, we used a cell based assay that makes quantification more robust and is capable of detecting multiple samples simultaneously. It is an alternative to the qualitative duckling bioassay which is the "gold-standard" assay currently being used for quantitative analysis of active AFB1. AFB1 was incubated with transduced Vero cells expressing the green fluorescence protein (GFP) gene. After excitation with blue light at 475 nm, cells emitted green light with emission peak at 509 nm. The result shows that AFB1 inhibits protein expression in a concentration dependent manner resulting in proportionately less GFP fluorescence in cells exposed to AFB1. The result also indicates strong positive linear relationship with R(2)=0.90 between the low cost CCD camera and a fluorometer, which costs 100 times more than a CCD camera. This new analytical method for measuring active AFB1 is low in cost and combined with in vitro assay, is quantitative. It also does not require the use of animals and may be useful especially for laboratories in regions with limited resources.

  15. Transfer modelling and toxicity evaluation of the effluent from an installation of cleansing and uranium recovery using a battery of bioassays.

    Science.gov (United States)

    Gagnaire, Béatrice; Boyer, Patrick; Bonzom, Jean-Marc; Lecomte-Pradines, Catherine; Simon, Olivier; Gilbin, Rodolphe

    2011-01-01

    On July 7, 2008, a leak of effluent from an Installation of Cleansing and Uranium Recovery (Tricastin, France) led to the spillage of uranium in a stream. The acute toxicity of the effluent was evaluated, and compared to the toxicity of uranium nitrate in bioassays using several organisms: Chlamydomonas reinhardtii, Daphnia magna, Chironomus riparius and Danio rerio. A sediment bioassay was also performed on C. riparius using water and sediment sampled along the river. Results showed that effluent EC(50) 72 h was 0.65 mg U/l for algae and LC(50) 48 h was 1.67 mg U/l for daphnia, while values obtained for uranium nitrate were higher. The LC(50) 96 h of effluent to C. riparius was 22.7 mg U/l, similar to value for uranium nitrate; the sediment collected was not toxic to C. riparius larvae. The LOEC of effluent and uranium nitrate on HT(50) of D. rerio were similar (0.03 mg U/l), but larvae were more sensitive to uranium nitrate than to effluent. Our results suggest that other substances contained in the effluent could potentially be toxic to wildlife in association with uranium. In parallel, the modelling of the transfers based on uranium measurements in the surface water was used to fill data gaps and assess the impact along the river. These results provided an estimate of exposure conditions that occurred along the river. This approach allowed us to see that the risk to ecosystem during this incident was certainly low and concerned a short period of time, but it could have existed at least for some species. PMID:21107686

  16. Dynamical chaos in chip-scale optomechanical oscillators

    CERN Document Server

    Wu, Jiagui; Huang, Yongjun; Zhou, Hao; Yang, Jinghui; Liu, Jia-Ming; Yu, Mingbin; Lo, Guoqiang; Kwong, Dim-Lee; Xia, Guangqiong; Wong, Chee Wei

    2016-01-01

    Chaos has revolutionized the field of nonlinear science and stimulated foundational studies from neural networks, extreme event statistics, to physics of electron transport. Recent studies in cavity optomechanics provide a new platform to uncover quintessential architectures of chaos generation and the underlying physics. Here we report the first generation of dynamical chaos in silicon optomechanical oscillators, enabled by the strong and coupled nonlinearities of Drude electron-hole plasma. Deterministic chaotic oscillation is achieved, and statistical and entropic characterization quantifies the complexity of chaos. The correlation dimension D2 is determined at ~ 1.67 for the chaotic attractor, along with a maximal Lyapunov exponent rate about 2.94*the fundamental optomechanical oscillation. The corresponding nonlinear dynamical maps demonstrate the plethora of subharmonics, bifurcations, and stable regimes, along with distinct transitional routes into chaotic states. The chaos generation in our mesoscopic...

  17. Chip-Scale Continuously Tunable Optical Orbital Angular Momentum Generator

    CERN Document Server

    Sun, Jie; Moresco, Michele; Coolbaugh, Douglas; Watts, Michael R

    2014-01-01

    Light carrying orbital angular momentum (OAM) has potential to impact a wide variety of applications ranging from optical communications to quantum information and optical forces for the excitation and manipulation of atoms, molecules, and micro-particles. The unique advantage of utilizing OAM in these applications relies, to a large extent, on the use of multiple different OAM states. Therefore, it is desirable to have a device that is able to gen- erate light with freely adjustable OAM states in an integrated form for large- scale integration. We propose and demonstrate a compact silicon photonic integrated circuit to generate a free-space optical beam with OAM state con- tinuously tuned from a single electrical input signal, realizing both integer and non-integer OAM states. The compactness and flexibility of the device and its compatibility with complementary metal-oxide-semiconductor (CMOS) pro- cessing hold promise for integration with other silicon photonic components for wide-ranging applications.

  18. Chip-scale Integrated Silica Ring Optical Gyro Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The next generation of space systems can benefit greatly by reduced c-SWaP integrated gyroscopes. By using photonic integration, it is possible to fit the entire...

  19. A chip-scale integrated cavity-electro-optomechanics platform

    CERN Document Server

    Winger, Martin; Alegre, Thiago P Mayer; Safavi-Naeini, Amir H; Meenehan, Seán; Cohen, Justin; Stobbe, Søren; Painter, Oskar

    2011-01-01

    We present an integrated optomechanical and electromechanical nanocavity, in which a common mechanical degree of freedom is coupled to an ultrahigh-Q photonic crystal defect cavity and an electrical circuit. The sys- tem allows for wide-range, fast electrical tuning of the optical nanocavity resonances, and for electrical control of optical radiation pressure back-action effects such as mechanical amplification (phonon lasing), cooling, and stiffening. These sort of integrated devices offer a new means to efficiently interconvert weak microwave and optical signals, and are expected to pave the way for a new class of micro-sensors utilizing optomechanical back-action for thermal noise reduction and low-noise optical read-out.

  20. A chip-scale integrated cavity-electro-optomechanics platform.

    Science.gov (United States)

    Winger, M; Blasius, T D; Mayer Alegre, T P; Safavi-Naeini, A H; Meenehan, S; Cohen, J; Stobbe, S; Painter, O

    2011-12-01

    We present an integrated optomechanical and electromechanical nanocavity, in which a common mechanical degree of freedom is coupled to an ultrahigh-Q photonic crystal defect cavity and an electrical circuit. The system allows for wide-range, fast electrical tuning of the optical nanocavity resonances, and for electrical control of optical radiation pressure back-action effects such as mechanical amplification (phonon lasing), cooling, and stiffening. These sort of integrated devices offer a new means to efficiently interconvert weak microwave and optical signals, and are expected to pave the way for a new class of micro-sensors utilizing optomechanical back-action for thermal noise reduction and low-noise optical read-out. PMID:22273884

  1. A chip-scale integrated cavity-electro-optomechanics platform

    DEFF Research Database (Denmark)

    Winger, M.; Blasius, T. D.; Mayer Alegre, T. P.;

    2011-01-01

    We present an integrated optomechanical and electromechanical nanocavity, in which a common mechanical degree of freedom is coupled to an ultrahigh-Q photonic crystal defect cavity and an electrical circuit. The system allows for wide-range, fast electrical tuning of the optical nanocavity...... resonances, and for electrical control of optical radiation pressure back-action effects such as mechanical amplification (phonon lasing), cooling, and stiffening. These sort of integrated devices offer a new means to efficiently interconvert weak microwave and optical signals, and are expected to pave...

  2. A review of metal (Pb and Zn) sensitive and pH tolerant bioassay organisms for risk screening of metal-contaminated acidic soils

    International Nuclear Information System (INIS)

    To improve risk estimates at the screening stage of Ecological Risk Assessment (ERA), short duration bioassays tailored to undisturbed soil cores from the contaminated site could be useful. However, existing standardized bioassays use disturbed soil samples and often pH sensitive organisms. This is a problem as naturally acidic soils are widespread. Changing soil properties to suit the test organism may change metal bioavailability, leading to erroneous risk estimates. For bioassays in undisturbed soil cores to be effective, species able to withstand natural soil properties must be identified. This review presents a critical examination of bioassay species' tolerance of acidic soils and sensitivity to metal contaminants such as Pb and Zn. Promising organisms include; Dendrobaena octaedra, Folsomia candida, Caenorhabditis elegans, Oppia nitens, Brassica rapa, Trifolium pratense, Allium cepa, Quercus rubra and Acer rubrum. The MetSTICK test and the Bait lamina test were also identified as suitable microorganism tests. -- Highlights: •Risk screening of metal contaminated soils should consider metal bioavailability. •Metal bioavailability is dependent on soil properties such as pH. •Many standardized bioassay organisms are sensitive to acidic soils. •This review identifies acid tolerant and metal sensitive bioassays and species. •The identified tests can improve risk screening of acidic metal contaminated soil. -- This review identifies bioassay species able to withstand naturally acidic soils while being sensitive to metal contaminants

  3. Comparative study of two bioassays with weakened duckweed and yeast treated with homeopathic preparations

    Directory of Open Access Journals (Sweden)

    Ursula Wolf

    2012-09-01

    Full Text Available In homeopathic basic research, the question as to the most adequate test systems and apt methodology is still open. This investigation examined the hypothesis that more complex organisms show stronger reactions to homeopathic remedies than less complex ones. We compared two Arsenic (As5+ stressed bioassays with duckweed (Lemna gibba, a multi-cellular autotrophic organism and yeast (Saccharomyces cerevisiae, a single-cellular heterotrophic organism regarding their response to homeopathic preparations [1]. For duckweed, growth rates of leaf area and leaf number were evaluated. For yeast, growth kinetics were determined by measuring slope, yield and Et50 (point in time when yield was half maximum of the sigmoid growth curve. The experiments with duckweed and yeast were performed in parallel (same day, same location and identical homeopathic preparations. After screening 17 substances, three homeopathic preparations (Arsenicum album, nosode, gibberellic acid were chosen for repeated experimental series [2]. Five independent experiments were conducted for each remedy with both organisms in parallel. Potency levels used were in the range of 17x–33x for duckweed and 17x–30x for yeast. To control for test system stability, systematic negative control experiments were conducted over the complete experimentation period. All experiments were blinded and randomized. The systematic negative control experiments did not yield any significant effects. Application of potentized Arsenicum album in the duckweed bioassay yielded the largest effects compared to water controls without remedies for the parameters leaf area and leaf number (p<0.001 [1, 3]. Potentized nosode preparations also had significant effects on duckweed's leaf area and leaf number (p<0.01. Growth was enhanced across all potency levels. In the yeast system the three homeopathic remedies did not show any significant effects on any growth curve parameter. The

  4. Development, validation and routine application of the in vitro REA and DR-CALUX reporter gene bioassays for the screening of estrogenic compounds and dioxins in food and feed

    OpenAIRE

    Bovee, T. F. H.

    2006-01-01

    A dedicated cell-line was developed by the Department of Toxicology of Wageningen University in a joined project with the University of California in Davis and the RIKILT-WUR - Institute of Food Safety in Wageningen. This DR-CALUX ® bioassay was tested, optimised and validated for its use to determine low elevated levels of dioxins in bovine milk around the existing limits. It was shown that this mammalian cell based test is very sensitive for 2,3,7,8-substituted dioxins and related PCBs, the...

  5. Facile synthesis of methotrexate intercalated layered double hydroxides: Particle control, structure and bioassay explore

    Energy Technology Data Exchange (ETDEWEB)

    Tian, De-Ying; Liu, Zhen-Lei [Jiangsu Key Laboratory of Biofunctional Material, College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210023 (China); Li, Shu-Ping, E-mail: lishuping@njnu.edu.cn [Jiangsu Key Laboratory of Biofunctional Material, College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210023 (China); Li, Xiao-Dong [Jiangsu Key Laboratory of Biofunctional Material, College of Chemistry and Material Science, Nanjing Normal University, Nanjing 210023 (China); Shenzhen Research Institute of Xiamen University, Shenzhen 518057 (China)

    2014-12-01

    To study the influence of particle size on drug efficacy and other properties, a series of methotrexate intercalated layered double hydroxides (MTX/LDHs) were synthesized through the traditional coprecipitation method, using a mixture of water and polyethylene glycol (PEG-400) as the solvent. To adjust the particle size of MTX/LDHs, the dropping way, the volume ratio of water to PEG-400 and different hydrothermal treatment time changed accordingly, and the results indicate that the particle size can be controlled between 90 and 140 nm. Elemental C/H/N and inductive coupled plasma (ICP) analysis indicated that different synthesis conditions almost have no effect on the compositions of the nanohybrids. X-ray diffraction (XRD) patterns manifested the successful intercalation of MTX anions into the LDH interlayers, and it's also found out that different volume ratios of water to PEG-400 and variable dropping way can affect the crystallinity of the final samples, i.e., the volume ratio of 3:1 and pH decreasing are proved to be optimum conditions. Furthermore, both antiparallel monolayer and bilayers adopting different orientations are suggested for four samples from XRD results. Fourier transform infrared spectroscopy (FTIR) investigations proved the coexistence of CO{sub 3}{sup 2−} and MTX anions in the interlayer of the nanohybrids. MTX/LDH particles exhibited hexagonal platelet morphology with round corner and different dropping ways can affect the morphology greatly. Moreover, a DSC study indicated that longer time treatment can weaken the bond between the MTX anions and LDH layers. The kinetic release profiles told us that larger MTX/LDH particles have enhanced the ability of LDH layers to protect interlayer molecules. At last, the bioassay study indicated that the nanohybrids with larger diameters have higher tumor suppression efficiency. - Graphical abstract: A series of methotrexate intercalated layered double hydroxides were synthesized by changing the

  6. Facile synthesis of methotrexate intercalated layered double hydroxides: Particle control, structure and bioassay explore

    International Nuclear Information System (INIS)

    To study the influence of particle size on drug efficacy and other properties, a series of methotrexate intercalated layered double hydroxides (MTX/LDHs) were synthesized through the traditional coprecipitation method, using a mixture of water and polyethylene glycol (PEG-400) as the solvent. To adjust the particle size of MTX/LDHs, the dropping way, the volume ratio of water to PEG-400 and different hydrothermal treatment time changed accordingly, and the results indicate that the particle size can be controlled between 90 and 140 nm. Elemental C/H/N and inductive coupled plasma (ICP) analysis indicated that different synthesis conditions almost have no effect on the compositions of the nanohybrids. X-ray diffraction (XRD) patterns manifested the successful intercalation of MTX anions into the LDH interlayers, and it's also found out that different volume ratios of water to PEG-400 and variable dropping way can affect the crystallinity of the final samples, i.e., the volume ratio of 3:1 and pH decreasing are proved to be optimum conditions. Furthermore, both antiparallel monolayer and bilayers adopting different orientations are suggested for four samples from XRD results. Fourier transform infrared spectroscopy (FTIR) investigations proved the coexistence of CO32− and MTX anions in the interlayer of the nanohybrids. MTX/LDH particles exhibited hexagonal platelet morphology with round corner and different dropping ways can affect the morphology greatly. Moreover, a DSC study indicated that longer time treatment can weaken the bond between the MTX anions and LDH layers. The kinetic release profiles told us that larger MTX/LDH particles have enhanced the ability of LDH layers to protect interlayer molecules. At last, the bioassay study indicated that the nanohybrids with larger diameters have higher tumor suppression efficiency. - Graphical abstract: A series of methotrexate intercalated layered double hydroxides were synthesized by changing the dropping way

  7. Synthesis, Characterization, and Application of Metal-Chelating Polymers for Mass Cytometric Bioassays

    Science.gov (United States)

    Majonis, Daniel

    This thesis describes the synthesis, characterization, and application of metal-chelating polymers for mass-cytometric bioassays. Mass cytometry is a cell characterization technique in which cells are injected individually into an ICP-MS detector. Signal is provided by staining cell-surface or intracellular antigens with metal-labeled antibodies (Abs). These Abs are labeled through the covalent attachment of metal-chelating polymers which carry multiple copies of a lanthanide isotope. In this work, my first goal was to develop a facile, straightforward synthesis of a new generation of metal-chelating polymers. The synthesis began with reversible addition-fragmentation chain transfer polymerization, and was followed by numerous post-polymerization pendant group transformations to introduce DTPA lanthanide chelators to every repeat unit, and a maleimide at the end of the chain. The second goal was to apply these metal-chelating polymers in bioassay experiments. The DTPA groups were loaded with lanthanide ions, and the maleimide group was used to covalently attach the polymer to an Ab. This goat anti-mouse conjugate was found to carry an average of 2.4 +/- 0.3 polymer chains. Then, primary Ab conjugates were prepared and used in an 11-plex mass cytometry assay in the characterization of umbilical cord blood cells. The third goal was to expand the multiplexity of the assay. In current technology, the number of Abs that can be monitored simultaneously is limited to the 31 commercially available, stable lanthanide isotopes. Thus, I had an interest in preparing metal-chelating polymers that could carry other metals in the 100-220 amu range. I synthesized polymers with four different polyaminocarboxylate ligands, and investigated the loading of palladium and platinum ions into these polymers. Polymer-Ab conjugates prepared with palladium- and platinum-loaded polymers gave curious results, in that only dead cells were recognized. The fourth goal was to create dual

  8. Evaluation of artificially-weathered standard fuel oil toxicity by marine invertebrate embryogenesis bioassays.

    Science.gov (United States)

    Bellas, Juan; Saco-Álvarez, Liliana; Nieto, Óscar; Bayona, Josep María; Albaigés, Joan; Beiras, Ricardo

    2013-01-01

    wWeathering of petroleum spilled in the marine environment may not only change its physical and chemical properties but also its effects on the marine ecosystem. The objective of this study was to evaluate the toxicity of the water-accommodated fraction (WAF) obtained from a standard fuel oil following an environmentally realistic simulated weathering process for a period of 80 d. Experimental flasks with 40 g L(-1) of fuel oil were incubated at 18°C with a 14 h light:10 h dark photoperiod and a photosynthetically active radiation (PAR) intensity of 70 μE m(-2) s(-1). Samples were taken at four weathering periods: 24 h, 7, 21 and 80 d. WAF toxicity was tested using the sea urchin (Paracentrotus lividus) and mussel (Mytilus galloprovincialis) embryo-larval bioassays and the aromatic hydrocarbons levels (AH) in the WAF were measured by gas chromatography/mass spectrometry. In contrast with the classic assumption of toxicity decrease with oil weathering, the present study shows a progressive increase in WAF toxicity with weathering, being the EC(50) after 80d eightfold lower than the EC(50) at day 1, whereas AH concentration slightly decreased. In the long term, inoculation of WAF with bacteria from a hydrocarbon chronically-polluted harbor slightly reduced toxicity. The differences in toxicity between fresh and weathered fuels could not be explained on the basis of the total AH content and the formation of oxidized derivatives is suggested to explain this toxicity increase.

  9. Effects of Jatropha curcas oil in Lactuca sativa root tip bioassays

    Directory of Open Access Journals (Sweden)

    LARISSA F. ANDRADE-VIEIRA

    2014-03-01

    Full Text Available Jatropha curcas L. (Euphorbiaceae is important for biofuel production and as a feed ingredient for animal. However, the presence of phorbol esters in the oil and cake renders the seeds toxic. The toxicity of J. curcas oil is currently assessed by testing in animals, leading to their death. The identification of toxic and nontoxic improved varieties is important for the safe use of J. curcas seeds and byproducts to avoid their environmental toxicity. Hence, the aim of this study was to propose a short-term bioassay using a plant as a model to screen the toxicity of J. curcas oil without the need to sacrifice any animals. The toxicity of J. curcas oil was evident in germination, root elongation and chromosomal aberration tests in Lactuca sativa. It was demonstrated that J. curcas seeds contain natural compounds that exert phyto-, cyto- and genotoxic effects on lettuce, and that phorbol esters act as aneugenic agents, leading to the formation of sticky chromosomes and c-metaphase cells. In conclusion, the tests applied have shown reproducibility, which is important to verify the extent of detoxification and to determine toxic doses, thus reducing the numbers of animals that would be used for toxicity tests.

  10. Bioassay data and a retention-excretion model for systemic plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Leggett, R.W.

    1984-05-01

    The estimation of systemic burdens from urinalyses has been the most common and useful method of quantifying occupational exposures to plutonium. Problems arise in using this technique, however, because of inadequate modeling of human retention, translocation, and excretion of this element. Present methods for estimating the systemic burden from urinalyses were derived to a large extent from patterns observed in the first few months after exposure, but there is now evidence that these same patterns do not persist over long periods. In this report we collect and discuss data needed for the interpretation of bioassay results for Pu. These data are used to develop a model that describes the movement, retention, and excretion of systemic Pu in the human body in terms of explicitly identified anatomical compartments. This model may be used in conjunction with existing models and/or case-specific information concerning the translocation of Pu from the respiratory or gastrointestinal tract or from wounds to the bloodstream. Attention is restricted to the behavior of Pu after it has gained access to the bloodstream. There remain significant uncertainties concerning some aspects of the movement of Pu, particularly its translocation from the liver. An attempt has been made to construct the model in such a way as to elucidate those areas needing further attention. 98 references, 18 figures, 16 tables.

  11. Comparative study on toxicity evaluation of anaerobically treated parboiled rice manufacturing wastewater through fish bioassay.

    Science.gov (United States)

    Giri, Dipti Ramesh; Singh, Ekta; Satyanarayan, Shanta

    2016-01-01

    Short term aquatic bioassay has been developed into a useful tool in water quality management. These tests give information on comparative toxicity of several compounds. The objective of this study was to evaluate the acute toxicity of raw and anaerobically treated effluents of the parboiled rice manufacturing industry. The acute toxicity test was carried out by using the fish Lebistes reticulatus under laboratory conditions. LC50 values for 24, 48, 72 and 96 hours ranged between 4.6 and 7.0% for the raw parboiled rice manufacturing wastewater. Two anaerobic fixed film fixed bed reactors and two different media matrices, i.e. UV stabilized Biopac media and Fugino spirals, were used for the treatment of parboiled rice mill wastewater. Effluents from these two reactors depicted LC50 values in the range of 68-88% and 62-78% for Biopac and Fugino spiral packed reactors, respectively. From the results, it is evident that anaerobically treated effluents from Biopac packed reactor is marginally better than Fugino spiral packed reactor. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality and effluent concentration. PMID:27120636

  12. Methods to improve routine bioassay monitoring for freshly separated, poorly transported plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Bihl, D.E.; Lynch, T.P.; Carbaugh, E.H.; Sula, M.J.

    1988-09-01

    Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than the 500-day half-time recommended for class Y plutonium in Publication 30 of the International Commission on Radiological Protection(ICRP). The more tenaciously retained material is referred to as super class Y plutonium. The ability to detect super class Y plutonium by current routine bioassay measurements is shown to be poor. Pacific Northwest Laboratory staff involved in the Hanford Internal Dosimetry Program investigated four methods to se if improvements in routine monitoring of workers for fresh super class Y plutonium are feasible. The methods were lung counting, urine sampling, fecal sampling, and use of diethylenetriaminepentaacetate (DTPA) to enhance urinary excretion. Use of DTPA was determined to be not feasible. Routine fecal sampling was found to be feasible but not recommended. Recommendations were made to improve the detection level for routine annual urinalysis and routine annual lung counting. 12 refs., 9 figs., 7 tabs.

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

    Science.gov (United States)

    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. PMID:22773148

  14. Towards the development of an embryotoxicity bioassay with terrestrial snails: Screening approach for cadmium and pesticides

    International Nuclear Information System (INIS)

    Currently no bioassays are available to assess the embryotoxicity of chemicals with terrestrial soil invertebrates. We therefore presented a new method for embryotoxicity testing with snail eggs: a relevant biological material that incubates in soil and that can be exposed to contaminants from leachates and soil solution. The effects of aqueous solutions of two herbicide formulations, Reglone (active ingredient (a.i.), diquat) and Roundup or its a.i., glyphosate, of a surfactant (Agral 90, a.i., nonylphenol polyethoxylates) and of cadmium (Cd) were studied. Endpoints were the hatching success and observations of embryo abnormalities after exposure. Roundup was found to be more toxic than its a.i. alone (EC50a.i. = 18 mg/l and about 1300 mg/l, respectively). Reglone (EC50a.i. = 0.72 mg/l) and Agral (EC50a.i. ∼ 50 mg/l) were also tested together, revealing that Reglone accounted for more than 99% of the mixture's toxicity. An antagonistic interaction between the two substances was found. For Cd (EC50 = 3.9 mg/l), a significant transfer from exposure medium to eggs was emphasized, particularly affecting the albumen. Abnormalities of embryogenesis in non-hatched embryos depended on the substance and the concentration considered.

  15. Characterization of dimeric forms of human pituitary growth hormone by bioassay, radioreceptor assay, and radioimmunoassay

    International Nuclear Information System (INIS)

    Seven highly purified dimeric forms of human pituitary growth hormone, composed of the monomeric forms 20 K hGH, 22K hGH and 24 k hBH linked together by noncovalent or covalent bounds, have been characterized by an in vitro bioassay (the Nb2 assay), a radioreceptor assay and a radioimmunoassay. Considerable differences in the ability to displace labelled recombinant hGH were observed in the radioreceptor assay. The seven dimeric forms varied over a range between 22 K hGH (most effective) and 20 K hGH. The three covalently-linked dimeric forms had nearly identical affinity constants. The mitogenic action of all but one of the hGH dimers in the Nb2 assay was in the same mutual order as the receptor binding activity in the radioreceptor assay. In the RIA, all dose-response curves were parallel except for those obtained with 20 K hGH and with the dimeric form (20 K-20 K)hGH. In this assay, dimeric variants of the constituents 22 K hGH and 24 K hGH were approximately twice as active as 22 K hGH on a molar basis, suggesting about the same affinity between the the antibodies and each of the monomeric forms. Determination of the amino acid compositions of the dimeric forms provided support for their content of monomeric constituents as established earlier by electrophoretic analysis. (author)

  16. Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study

    Energy Technology Data Exchange (ETDEWEB)

    Dai, Chao-Fan; Tian, De-Ying; Li, Shu-Ping, E-mail: lishuping@njnu.edu.cn; Li, Xiao-Dong

    2015-12-01

    Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells. - Highlights: • Surfactants could be used to modify the dispersing state of MTX/LDHs hybrids. • Surfactants have great effect on the morphology of MTX/LDHs hybrids. • MTX/LDHs with good monodisperse degree are more efficient in the suppression of the tumor cells.

  17. Preparative Purification and Bioassay of Bt Toxin from Cry1Ab Transgenic Rice

    Institute of Scientific and Technical Information of China (English)

    WU Jian-min; YE Qin-fu

    2004-01-01

    A method of extracting and purifying Cry1Ab protein(Bt toxin) from Cry1Ab transgenic rice was established. Most of the Bt toxin present in the tissue of Cry1Ab transgenic rice was extracted effectively with a solution of 50 mmol/LNa2CO3 and NaHCO3. The crude protein containing Bt toxin was obtained after the pretreatment of Cry1Ab transgenic rice with ultra-filtration, ammonium sulfate precipitation and centrifugation. The dialysed crude protein was futher separated on DEAE Sephadex A-50 columns and Sephadex G-150 columns. The protein bound on DEAE Sephadex A-50 gel was eluted with buffer solution B(10 mmol/L trisHCl buffer+1. 0 mmol/L EDTA, pH=8.0) mixed with 0. 1, 0. 3, 0. 5 and 0. 8 mol/L NaCl in a discontinuous gradient elution mode. The peak of the Bt toxin eluted from the columns was identified by ELISA and bioassayed with larvae of tobacco hornworms and silkworms. The purity and the bioactivity of the Bt toxin were determined by means of SDS-PAGE and larvicidal assay, respectively. The purity of the Bt toxin obtained by this method is high, and its insecticidal activity is retained after the toxin is purified.

  18. A novel high-throughput irradiator for in vitro radiation sensitivity bioassays

    Science.gov (United States)

    Fowler, Tyler L.

    Given the emphasis on more personalized radiation therapy there is an ongoing and compelling need to develop high-throughput screening tools to further examine the biological effects of ionizing radiation on cells, tissues and organ systems in either the research or clinical setting. Conventional x-ray irradiators are designed to provide maximum versatility to radiobiology researchers, typically accommodating small animals, tissue or blood samples, and cellular applications. This added versatility often impedes the overall sensitivity and specificity of an experiment resulting in a trade-off between the number of absorbed doses (or dose rates) and biological endpoints that can be investigated in vitro in a reasonable amount of time. Therefore, modern irradiator designs are incompatible with current high-throughput bioassay technologies. Furthermore, important dosimetry and calibration characteristics (i.e. dose build-up region, beam attenuation, and beam scatter) of these irradiators are typically unknown to the end user, which can lead to significant deviation between delivered dose and intended dose to cells that adversely impact experimental results. Therefore, the overarching goal of this research is to design and develop a robust and fully automated high-throughput irradiator for in vitro radiation sensitivity investigations. Additionally, in vitro biological validation of this system was performed by assessing intracellular reactive oxygen species production, physical DNA double strand breaks, and activation of cellular DNA repair mechanisms. Finally, the high-throughput irradiator was used to investigate autophagic flux, a cellular adaptive response, as a potential biomarker of radiation sensitivity.

  19. Bioassay-Directed Isolation of Active Compounds with Antiyeast Activity from a Cassia fistula Seed Extract

    Directory of Open Access Journals (Sweden)

    Subramanion L. Jothy

    2011-09-01

    Full Text Available Background and objective: Cassia fistula L belongs to the family Leguminosae, and it is one of the most popular herbal products in tropical countries. C. fistula seeds have been used as a herbal medicine and have pharmacological activity which includes anti-bacterial, anti-fungal, and antioxidant properties. The goal of this study was to identify compounds from C. fistula seeds which are responsible for anti-Candida albicans activity using bioassay-directed isolation. Results: The preliminary phytochemical screening of the plant seed revealed the presence of anthraquinones, flavonoids, saponins, tannins and terpenoids. The isolation of active compounds was carried out in four steps: multiple extractions, fractionation using column chromatography and purification using preparative thin-layer chromatography (TLC and liquid chromatography/mass spectrometry (LC/MS. The structure of separated compounds was determined on the basis of mass spectrometry data. One compound was identified is roseanone. Conclusions: The MS analysis on the active fraction from seed extract of C. fistula confirmed the presence of roseanone with antiyeast activity.

  20. Characterization of urinary volatiles in Swiss male mice (Mus musculus): bioassay of identified compounds

    Indian Academy of Sciences (India)

    S Achiraman; G Archunan

    2002-12-01

    The present study was carried out to investigate the chemical nature of the urine of male mice and to assess its bioactivity. Urine of mature male mice was extracted with dichloromethane (1 : 1 ratio v/v) and analysed by gas-chromatography linked mass-spectrometry (GC-MS). Ten different compounds such as alkanes, alcohols, etc. were detected in the urine. Among the ten, five compounds are specific to males, namely 3-cyclohexene-1-methanol (I), 3-amino-s-triazole (II), 4-ethyl phenol (III), 3-ethyl-2,7-dimethyl octane (IV) and 1-iodoundecane (V). The compound, 4-ethylphenol, has been previously reported in several strains of male mice. Furthermore, the compounds (II) and (IV) are similar to 2-sec-butylthiazole and dehydro-exo-brevicomin compounds which have already been reported in male mice. Bioassay revealed that compounds (II), (III) and (IV) were responsible for attracting females and in inducing aggression towards males, as compared to the other compounds, i.e. (I) and (V). The results indicate that these three volatiles (II, III and IV) of male mice appear to act as attractants of the opposite sex.

  1. Towards the development of an embryotoxicity bioassay with terrestrial snails: Screening approach for cadmium and pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Druart, Coline; Scheifler, Renaud [Department of Chrono-Environment, University of Franche-Comte, UMR UFC/CNRS 6249 usc INRA, Place Leclerc, F-25030 Besancon Cedex (France); Vaufleury, Annette de, E-mail: annette.devaufleury@univ-fcomte.fr [Department of Chrono-Environment, University of Franche-Comte, UMR UFC/CNRS 6249 usc INRA, Place Leclerc, F-25030 Besancon Cedex (France)

    2010-12-15

    Currently no bioassays are available to assess the embryotoxicity of chemicals with terrestrial soil invertebrates. We therefore presented a new method for embryotoxicity testing with snail eggs: a relevant biological material that incubates in soil and that can be exposed to contaminants from leachates and soil solution. The effects of aqueous solutions of two herbicide formulations, Reglone (active ingredient (a.i.), diquat) and Roundup or its a.i., glyphosate, of a surfactant (Agral 90, a.i., nonylphenol polyethoxylates) and of cadmium (Cd) were studied. Endpoints were the hatching success and observations of embryo abnormalities after exposure. Roundup was found to be more toxic than its a.i. alone (EC50{sub a.i.} = 18 mg/l and about 1300 mg/l, respectively). Reglone (EC50{sub a.i.} = 0.72 mg/l) and Agral (EC50{sub a.i.} {approx} 50 mg/l) were also tested together, revealing that Reglone accounted for more than 99% of the mixture's toxicity. An antagonistic interaction between the two substances was found. For Cd (EC50 = 3.9 mg/l), a significant transfer from exposure medium to eggs was emphasized, particularly affecting the albumen. Abnormalities of embryogenesis in non-hatched embryos depended on the substance and the concentration considered.

  2. Evaluation of acute ecotoxicity removal from industrial wastewater using a battery of rapid bioassays.

    Science.gov (United States)

    Dries, Jan; Daens, Dominique; Geuens, Luc; Blust, Ronny

    2014-01-01

    The present study compares conventional wastewater treatment technologies (coagulation-flocculation and activated sludge) and powdered activated carbon (PAC) treatment for the removal of acute ecotoxicity from wastewater generated by tank truck cleaning (TTC) processes. Ecotoxicity was assessed with a battery of four commercially available rapid biological toxicity testing systems, verified by the US Environmental Protection Agency. Chemical coagulation-flocculation of raw TTC wastewater had no impact on the inhibition of the bioluminescence by Vibrio fischeri (BioTox assay). Subsequent biological treatment with activated sludge without PAC resulted in BioTox inhibition-free effluent (activated sludge treatment without PAC produced an effluent that significantly inhibited (>50%) (i) the bioluminescence by Photobacterium leiognathi (ToxScreen³ test kit), (ii) the photosynthesis by the green algae Chlorella vulgaris (LuminoTox SAPS test kit), and (iii) the particle ingestion by the crustacean Thamnocephalus platyurus (Rapidtoxkit test kit). The lowest inhibition was measured after activated sludge treatment with the highest PAC dose (400 mg/L), demonstrating the effectiveness of PAC treatment for ecotoxicity removal from TTC wastewater. In conclusion, the combination of bioassays applied in the present study represents a promising test battery for rapid ecotoxicty assessment in wastewater treatment. PMID:25521143

  3. Isolation of antibacterial compounds from Quercus dilatata L. through bioassay guided fractionation

    Directory of Open Access Journals (Sweden)

    Jamil Maryam

    2012-05-01

    Full Text Available Abstract Background Four medicinal plants (Chrozophora hierosolymitana Spreng, Chrysanthemum leucanthemum L., Ephedra gerardiana Wall. ex Stapf, and Quercus dilatata L. used by indigenous healers to treat various infectious diseases were selected for the present study. The major objective of the present study was isolation and characterization of antimicrobial components from the crude plant extracts using bioassay guided fractionation. Methods Seven methanolic extracts of the four plants were screened to identify any antimicrobial agents present in them. The active crude plant extract was fractionated first by solvent partitioning and then by HPLC. Characterization of the active fractions was done by using spectrophotometer. Results All the seven methanolic extracts showed low antifungal activity, however, when these extracts were tested for antibacterial activity, significant activity was exhibited by two extracts. The extract of aerial parts of Q. dilatata was most active and therefore, was selected for further analysis. Initially fractionation was done by solvent-solvent partitioning and out of six partitioned fractions, ethanol fraction was selected on the basis of results of antibacterial activity and phytochemical analysis. Further, fractionation was carried out by RP- HPLC and purified active subfractions were characterized by comparing their absorption spectra with that of the known natural products isolated from the plants of Quercus genus. Discussion and conclusion The results suggest that this is the first report of the isolated antibacterial compounds from this genus.

  4. Bed rest suppresses bioassayable growth hormone release in response to muscle activity

    Science.gov (United States)

    McCall, G. E.; Goulet, C.; Grindeland, R. E.; Hodgson, J. A.; Bigbee, A. J.; Edgerton, V. R.

    1997-01-01

    Hormonal responses to muscle activity were studied in eight men before (-13 or -12 and -8 or -7 days), during (2 or 3, 8 or 9, and 13 or 14 days) and after (+2 or +3 and +10 or +11 days) 17 days of bed rest. Muscle activity consisted of a series of unilateral isometric plantar flexions, including 4 maximal voluntary contractions (MVCs), 48 contractions at 30% MVC, and 12 contractions at 80% MVC, all performed at a 4:1-s work-to-rest ratio. Blood was collected before and immediately after muscle activity to measure plasma growth hormone by radioimmunoassay (IGH) and by bioassay (BGH) of tibia epiphyseal cartilage growth in hypophysectomized rats. Plasma IGH was unchanged by muscle activity before, during, or after bed rest. Before bed rest, muscle activity increased (P muscle activity, a pattern that persisted through 8 or 9 days of bed rest. However, after 13 or 14 days of bed rest, plasma concentration of BGH was significantly lower after than before muscle activity (2,594 +/- 211 to 2,085 +/- 109 microg/l). After completion of bed rest, muscle activity increased BGH by 31% at 2 or 3 days (1,807 +/- 117 to 2,379 +/- 473 microg/l; P muscle activity.

  5. Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

    Science.gov (United States)

    Gosselink, K. L.; Grindeland, R. E.; Roy, R. R.; Zhong, H.; Bigbee, A. J.; Grossman, E. J.; Edgerton, V. R.

    1998-01-01

    There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

  6. Development of a bioassay using walleye (Sander vitreus) to assess the toxicity of oil sands sediments

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Yuan, H.; Tumber, V.; Parrott, J. [Environment Canada, Ottawa, ON (Canada); Raine, J. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2010-07-01

    This study examined the effects of sediments from the Athabasca oil sands area on fish development and survival. Walleye (Sander vitreus) which inhabit the Athabasca River are exposed to natural sources of bitumen eroding from the McMurray formation. This study described the design and implementation of a daily-renewal bioassay to evaluate the potential effects of toxicants on walleye development. Eggs were collected and fertilized with milt from spawning wild walleye captured from Lake Diefenbaker in Saskatchewan. The fertilized eggs were exposed to different concentrations of sediments or culture water only (negative controls) until complete yolk absorption of control fish. The walleye embryos were fed brine shrimp daily after hatching and the developing fish were examined for morphological deformities, survival, hatching success, and changes in weight and length between treatments. Organics concentrations in fish tissues and water were measured when possible. Fathead minnows and northern pikes will also be exposed to the same sediments in order to compare the relative sensitivity of the three species.

  7. Development of a bioassay to assess the toxicity of oil sands sediments to pike (Esox lucius)

    Energy Technology Data Exchange (ETDEWEB)

    Turcotte, D.; Yuan, H.; Tumber, V.; Parrott, J. [Environment Canada, Ottawa, ON (Canada); Raine, J. [Saskatchewan Univ., Saskatoon, SK (Canada)

    2010-07-01

    Pike (Esox lucius) are a commercially sought fish species that inhabit the Athabasca River, which flows through the Athabasca oil sands. The fish are exposed to natural sources of bitumen from the McMurray formation. This study was conducted to design and implement a daily-renewal bioassay to assess the toxicity of oil sands to this fish species and to obtain information regarding the development of pike exposed to bitumen. Eggs were collected and fertilized with milt from spawning wild pike captured from Lake Diefenbaker in Saskatchewan. The fertilized eggs were exposed to different concentrations of sediments or culture water only (negative controls) until complete yolk absorption of control fish, approximately 15 days post-hatch. For the rest of the experiment, brine shrimp were fed to the walleye embryos every day after hatching. The developing fish were examined for morphological deformities, survival, hatching success, and changes in weight and length. The research findings indicated that pike is less sensitive than walleye and fathead minnow to the toxicity of oil sands sediments.

  8. Statistical evaluation of mortality in long-term carcinogenicity bioassays using a Williams-type procedure.

    Science.gov (United States)

    Herberich, Esther; Hothorn, Ludwig A

    2012-10-01

    Several doses and a control group can be compared under order restriction using the Williams procedure for normally distributed endpoints assuming variance homogeneity. Comparison of the survival functions represents a secondary endpoint in long-term in vivo bioassays of carcinogenicity. Therefore, a Williams-type procedure for the comparison of survival functions is proposed for the assumption of the Cox proportional hazards model or the general frailty Cox model to allow a joint analysis over sex and strains. Interpretation according to both statistical significance and biological relevance is possible with simultaneous confidence intervals for hazard ratios. Related survival data can be analyzed using the R packages survival, coxme, and multcomp. Together with the R packages MCPAN and nparcomp, Dunnett- or Williams-type procedures are now available for the statistical analysis of the following endpoint types in toxicology: (i) normally distributed, (ii) non-normally distributed, (iii) score (ordered categorical) data, (iv) crude proportions, (v) survival functions, and (vi) time-to-tumor data with and without cause-of-death information.

  9. Use of Salmonella/microsome reversion bioassay for monitoring industrial wastewater treatment plants in Rajasthan, India.

    Science.gov (United States)

    Mathur, Nupur; Bhatnagar, Pradeep; Bakre, Prakash

    2012-05-01

    Salmonella/microsome reversion assay was used as a biological parameter for monitoring the toxicity of common effluent treatment plant (CETP), Mandia road industrial area, Pali catering to textile industrial areas in Pali, Rajasthan. The influent and effluent water of CETP, surface water (Bandi river) and underground water were tested using Ames bioassay. The results showed presence of mutagens in surface water of Bandi river and the underground water in Pali. Further, comparison of mutagenicity of CETP influent and effluent water revealed that the treatment method employed at this plant has failed to remove mutagenic substances present in Pali textile wastewater. The study also showed that Ames assay is an important tool in genotoxic studies because of its simplicity, sensitivity to genetic damage, speed, low cost of experimentation and small amount of sample required. Further Ames assay, as seen from the results of this study, can be used as a monitoring tool for not only CETPs but also for other water resources. The outcomes of the Ames assay demonstrated its performance as a sensitive, cost-effective and relatively rapid screening tool to assess the genotoxic potential of complex environmental samples. PMID:23029899

  10. Bioassay and Identification of Root Exudates of Three Fruit Tree Species

    Institute of Scientific and Technical Information of China (English)

    Jiang-Hong Zhang; Zhi-Quan Mao; Li-Qin Wang; Huai-Rui Shu

    2007-01-01

    A laboratory bioassay was designed to determine the allelopathic potential of root exudates of three fruit tree species on apple germination. The results showed that root exudates of apple (Malus pumila L.) and peach (Prunus persica L.), each at concentrations of 0.02 and 0.2 mg/L, inhibited germination and radicle growth of apple seeds by 56.7%, 60.7%, 51.5%, and 59.3%, respectively. The corresponding shoot growth inhibition rate was 49.5%, 46.7%, 36.4%, and 44%, respectively. Root exudates of jujube (Ziziphus jujuba Mill.) had no significant effect on apple seeds.Qualitative determination of root exudates of apple, peach, and jujube tree was developed with gas chromatography-mass spectrometry. The root exudates of apple seedlings mainly contain organic acids, glycol, esters, and benzenphenol derivatives. Peach root exudates contained phenolic acids and benzenphenol derivatives in addition to two unidentified compounds. The root exudates of jujube did not contain any phenolic acids.

  11. Hazard characterization and identification of a former ammunition site using microarrays, bioassays, and chemical analysis.

    Science.gov (United States)

    Eisentraeger, Adolf; Reifferscheid, Georg; Dardenne, Freddy; Blust, Ronny; Schofer, Andrea

    2007-04-01

    More than 100,000 tons of 2,4,6-trinitrotoluene were produced at the former ammunition site Werk Tanne in Clausthal-Zellerfeld, Germany. The production of explosives and consequent detonation in approximately 1944 by the Allies caused great pollution in this area. Four soil samples and three water samples were taken from this site and characterized by applying chemical-analytical methods and several bioassays. Ecotoxicological test systems, such as the algal growth inhibition assay with Desmodesmus subspicatus, and genotoxicity tests, such as the umu and NM2009 tests, were performed. Also applied were the Ames test, according to International Organization for Standardization 16240, and an Ames fluctuation test. The toxic mode of action was examined using bacterial gene profiling assays with a battery of Escherichia coli strains and with the human liver cell line hepG2 using the PIQOR Toxicology cDNA microarray. Additionally, the molecular mechanism of 2,4,6-trinitrotoluene in hepG2 cells was analyzed. The present assessment indicates a danger of pollutant leaching for the soil-groundwater path. A possible impact for human health is discussed, because the groundwater in this area serves as drinking water. PMID:17447547

  12. Productivity of chironomid larvae exposed to oil sands process water : in situ vs. lab bioassay results

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, K.; Ciborowski, J. [Windsor Univ., ON (Canada)

    2010-07-01

    Oil sands process water (OSPW) contains toxic concentrations of salts and napthenic acids that may compromise wetland reclamation efforts. The productivity of wetland biota is one of the criteria used by the Alberta government to determine if land leased to oil sands mining companies is restored. This study determined how chironomid productivity is influenced by the water from oil sands process material (OSPM) affected wetland. In this study, 26 10-day in situ and laboratory bioassays from water of three oil sands process material (OSPM) were compared with water from 3 reference wetlands to determine the influence of water from OSPM affected wetlands on chironomid productivity. Parallel studies were conducted with Chironomus riparius lab-cultured larvae and Chironomus sp larvae cultured from egg masses collected from an OSPW-affected wetland. In situ, chironomids were housed in small cylinders with fine-mesh netting to allow water exchange and contact with the sediment. Preliminary estimates of chironomids emerging from study wetlands indicated that native and lab cultured chironomids are not uniformly responsive to OSPW.

  13. Phytoassessment of acid mine drainage: Lemna gibba bioassay and diatom community structure.

    Science.gov (United States)

    Gerhardt, A; de Bisthoven, L Janssens; Guhr, K; Soares, A M V M; Pereira, M J

    2008-01-01

    An integrated multilevel phytoassessment of an acid mine drainage (AMD, pH range 3.3-6.8) in southern Portugal was performed. A 7-day phytotoxicity bioassay with the duckweed Lemna gibba (chlorosis, necrosis, growth) was carried out, both in the laboratory and in situ, combined with an analysis of the resident epilithic diatom community. The toxicity test was performed with water from the AMD gradient, an unpolluted river control and acidified control water, in order to discriminate potential pH-effects from combined pH- and metal-effects. Diatom communities discriminated well among the sites (alkalophilic species versus halobiontic, acidobiontic and acidophilic species), showing inter-site differences to be larger than intra-site seasonal variations. In L. gibba exposed to AMD, necrosis and growth inhibition were higher in situ compared to the laboratory experiments. L. gibba was more sensitive to AMD than to acidified water. Already after 4 days, growth rate inhibition in L. gibba proved to be a reliable indicator of AMD-stress. Ecotoxicological thresholds obtained with L. gibba corresponded with those obtained previously with animals of intermediate tolerance to AMD. The results were summarised in a multimetric index. PMID:17952593

  14. Results of an in-situ mussel bioassay in the Puget Sound

    Energy Technology Data Exchange (ETDEWEB)

    Houkal, D.; Rummel, B.; Shephard, B. [URS Consultants, Inc., Seattle, WA (United States)

    1995-12-31

    As part of an ecological evaluation in the Puget Sound, Washington, an in situ bioassay using the blue mussel (Mytilus galloprovincialis) was conducted to determine the effect of sediment-borne chemicals on bioaccumulation and growth of shellfish. The assay included four sample stations from a contaminated embayment (Sinclair Inlet) and one station from a reference site (Holmes Harbor). At each station, 300 mussels were deployed 1 meter above the sediment surface and maintained for a period of 3 months. The length and total weight of each mussel was measured at the beginning of the exposure period and the length, total weight, tissue weight, and shell weight of each mussel was measured at the end of the exposure period. Composite tissue samples from 100 mussels were collected at the beginning and end of the exposure period and analyzed for semivolatile organic chemicals, chlorinated pesticides, polychlorinated biphenyls, inorganic chemicals, organotin, and lipids. Water quality measurements (including temperature, salinity, dissolved oxygen, and chlorophyll a) were made at each station every two weeks during the assay to characterize environmental factors influencing mussel bioaccumulation and growth. Weight growth was similar among stations in Sinclair Inlet, but was significantly greater in all Sinclair Inlet stations compared to the Holmes Harbor reference station. Length growth was statistically indistinguishable among stations in Sinclair Inlet. Only one Sinclair Inlet station had a significantly greater length growth compared to the Holmes Harbor reference station. The influence of water quality on mussel growth is presented. The correlation between sediment chemistry and bioaccumulation is discussed.

  15. Development of a bioassay using walleye (Sander vitreus) to assess the toxicity of oil sands sediments

    International Nuclear Information System (INIS)

    This study examined the effects of sediments from the Athabasca oil sands area on fish development and survival. Walleye (Sander vitreus) which inhabit the Athabasca River are exposed to natural sources of bitumen eroding from the McMurray formation. This study described the design and implementation of a daily-renewal bioassay to evaluate the potential effects of toxicants on walleye development. Eggs were collected and fertilized with milt from spawning wild walleye captured from Lake Diefenbaker in Saskatchewan. The fertilized eggs were exposed to different concentrations of sediments or culture water only (negative controls) until complete yolk absorption of control fish. The walleye embryos were fed brine shrimp daily after hatching and the developing fish were examined for morphological deformities, survival, hatching success, and changes in weight and length between treatments. Organics concentrations in fish tissues and water were measured when possible. Fathead minnows and northern pikes will also be exposed to the same sediments in order to compare the relative sensitivity of the three species.

  16. Development of a bioassay to assess the toxicity of oil sands sediments to pike (Esox lucius)

    International Nuclear Information System (INIS)

    Pike (Esox lucius) are a commercially sought fish species that inhabit the Athabasca River, which flows through the Athabasca oil sands. The fish are exposed to natural sources of bitumen from the McMurray formation. This study was conducted to design and implement a daily-renewal bioassay to assess the toxicity of oil sands to this fish species and to obtain information regarding the development of pike exposed to bitumen. Eggs were collected and fertilized with milt from spawning wild pike captured from Lake Diefenbaker in Saskatchewan. The fertilized eggs were exposed to different concentrations of sediments or culture water only (negative controls) until complete yolk absorption of control fish, approximately 15 days post-hatch. For the rest of the experiment, brine shrimp were fed to the walleye embryos every day after hatching. The developing fish were examined for morphological deformities, survival, hatching success, and changes in weight and length. The research findings indicated that pike is less sensitive than walleye and fathead minnow to the toxicity of oil sands sediments.

  17. Effects of Jatropha curcas oil in Lactuca sativa root tip bioassays.

    Science.gov (United States)

    Andrade-Vieira, Larissa F; Botelho, Carolina M; Laviola, Bruno G; Palmieri, Marcel J; Praça-Fontes, Milene M

    2014-03-01

    Jatropha curcas L. (Euphorbiaceae) is important for biofuel production and as a feed ingredient for animal. However, the presence of phorbol esters in the oil and cake renders the seeds toxic. The toxicity of J. curcas oil is currently assessed by testing in animals, leading to their death. The identification of toxic and nontoxic improved varieties is important for the safe use of J. curcas seeds and byproducts to avoid their environmental toxicity. Hence, the aim of this study was to propose a short-term bioassay using a plant as a model to screen the toxicity of J. curcas oil without the need to sacrifice any animals. The toxicity of J. curcas oil was evident in germination, root elongation and chromosomal aberration tests in Lactuca sativa. It was demonstrated that J. curcas seeds contain natural compounds that exert phyto-, cyto- and genotoxic effects on lettuce, and that phorbol esters act as aneugenic agents, leading to the formation of sticky chromosomes and c-metaphase cells. In conclusion, the tests applied have shown reproducibility, which is important to verify the extent of detoxification and to determine toxic doses, thus reducing the numbers of animals that would be used for toxicity tests. PMID:24676174

  18. Bioassay procedures and health physics recommendations for a promethium-147 luminescent dial painting industry

    International Nuclear Information System (INIS)

    A study was conducted to determine the hazard to workers who were applying a radioactive luminescent paint to devices such as clock dials and hands, signs, etc. The paint used was a mixture of macrospheres containing 147Pm, ZnS, and a binder. It was applied by workers either manually or by machine. This study was designed to determine the radiological safety of these operations. The potential routes of intake of 147Pm by workers were identified as inhalation and ingestion. Air samples were taken at work stations; total and respirable-sized 147Pm particles were measured. Both were shown to be at a safe level. An animal inhalation study was conducted to determine deposition of respirable-sized 147Pm particles. Testing by a bioassay procedure developed specifically for this purpose revealed low levels of deposited activity in the respiratory systems of these animals. A health physics evaluation of the dial painting facility firm and operation revealed that extensive improvements in engineering controls and worker protection were needed. The health physics recommendations made, as a result, should be adopted as a minimum for maximization of long term benefits to both the employee and the employer

  19. ANTIMICROBIAL SCREENING AND BRINE SHRIMP LETHALITY BIOASSAY OF TINOSPORA CORDIFOLIA (FAM: MENISPERMACEAE

    Directory of Open Access Journals (Sweden)

    Mohammad Kaisarul Islam

    2011-12-01

    Full Text Available Tinospora cordifolia (Fam: Menispermaceae has been investigated for evaluation of the biological activities. The stem of Tinospora cordifolia were extracted with carbon tetrachloride, n-hexane and methanol were collected and afford 4.0 mg, 4.0 mg, and 4.0 mg, respectively for the test. The crude carbon tetrachloride, n-hexane, and methanol extract of the plant were subjected to antimicrobial screening against 15 microorganisms such as gram-positive, gram-negative, fungi by the disc diffusion method. But interestingly no fraction showed any inhibitory effect against all the microorganisms. In the brine shrimp lethality bioassay, carbon tetrachloride fraction showed high toxicity, where LC90 value was only 6.25 mg/ml. The methanol crude extract and n-hexane fraction showed LC50 of 1.563 and 6.05 mg/ml respectively with very narrow therapeutic index (LC90 of 43.0 mg/ml and 45.0 mg/ml respectively. This indicated that the cytotoxicity exhibited by the carbon tetra chloride, n-hexane, and methanol extract was very significant.

  20. Seed germination bioassay using maize seeds for phytoxicity evaluation of different composted materials

    International Nuclear Information System (INIS)

    In this paper we evaluated the phytotoxicity of different composts obtained by two different composting methods using seed germination bioassay. Seeds of Zea mays were sown in 1:5 extract of composts and these were compared with the control (100% distilled water) for each type of material. Composting of herbal pharmaceutical solid waste (HPSW) was carried out using both conventional bin and pit method. HPSW was mixed separately with poultry manure, cow-manure and goat manure in three different ratios. Uncomposted and composted HPSW were tested to study the Phytotoxicity on Zea mays seed germination, after composting increase in percent germination as well as germination index (GI) values were observed in all combinations regardless, composted by pit or bin method. The results clearly showed that composting reduced Phytotoxicity. The results showed that use of completely composted organic waste reduces the phytotoxicity and is better than the use of uncomposted waste. It was found that pit method was more suitable than bin method. Herbal waste with goat manure in 1:1 ratio was found to be the most effective combination as compared to other combinations here. Germination was 100% and the germination index was 1.4 whereas uncomposted HPSW showed the lowest percent germination i.e., 77% and germination index 52.31 respectively. (author)

  1. Double incision wound healing bioassay using Hamelia patens from El Salvador.

    Science.gov (United States)

    Gomez-Beloz, Alfredo; Rucinski, James C; Balick, Michael J; Tipton, Camille

    2003-10-01

    Hamelia patens Jacq. (Rubiaceae) has received little attention in the laboratory for its wound healing ability even though it is commonly used as a treatment for wounds throughout Central America. A double incision wound healing bioassay was carried out with a crude extract of Hamelia patens collected from El Salvador. Animals were divided into three groups. Group I (n = 14) had the left incision treated with 5% (w/w) Hamelia patens and the contralateral side with petroleum jelly (PJ). Group II (n = 14) had the left incision treated with 10% (w/w) ointment and the contralateral side with petroleum jelly. Group III (n = 10) had the left incision treated with petroleum jelly and the contralateral side left untreated. Breaking strength of the incisions was measured on day 7 and day 12. For Groups I and II, there was no significant difference between treatment and control incisions at day 7. On day 12, there was a significant difference between the treated and control incisions for Groups I and II. There was no significant difference between petroleum jelly and untreated incisions for Group III on day 7 and day 12. Hamelia patens does increase breaking strength of wounds significantly more than the control group. Further wound healing studies of this plant are warranted.

  2. Assessment of toxic potential of Cerrado fruit seeds using Artemia salina bioassay

    Directory of Open Access Journals (Sweden)

    Raíza Cavalcante Fonseca

    2013-06-01

    Full Text Available Artemia salina bioassay was used to assess toxicity of seeds and kernels of Brazilian fruits from cerrado (central high plains region and other inner regions of the country. Water extracts of the kernels were filtered and added to Artemia cultures containing ten individuals per mL. Dose - response curves were constructed, and LD50 values were calculated. Pure potassium cyanide standard was used to draw a calibration curve for comparison to detect the presence of cyanide in the samples tested. Extracts of the seeds of araticum, mangaba, cagaita, jatobá, and tucumã were found toxic to Artemia salina, and some of the dose - response curves were very similar in shape to those obtained with pure potassium cyanide standards, while the samples of baru, cajá-manga, siriguela, trauma, and veludo showed no toxicity at all. The Guignard test, specific for cyanide detection, showed negative results in all toxic samples, suggesting the presence of other toxic compounds rather than cyanide. The comparison of araticum dose - response curve with those of other annonaceous fruits suggests the presence acetogenins as the main toxic compounds in the seeds. These results could be useful to prevent poisoning by industrial derivatives of the fruits studied.

  3. Methotrexate intercalated layered double hydroxides with the mediation of surfactants: Mechanism exploration and bioassay study

    International Nuclear Information System (INIS)

    Methotrexatum intercalated layered double hydroxides (MTX/LDHs) hybrids were synthesized by the co-precipitation method and three kinds of nonionic surfactants with different hydrocarbon chain lengths were used. The resulting hybrids were then characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). XRD and FTIR investigations manifest the successful intercalation of MTX anions into the interlayer of LDHs. TEM graphs indicate that the morphology of the hybrids changes with the variation of the chain length of the surfactants, i.e., the particles synthesized using polyethylene glycol (PEG-7) present regular disc morphology with good monodispersity, while samples with the mediation of alkyl polyglycoside (APG-14) are heavily aggregated and samples with the addition of polyvinylpyrrolidone (PVP-10) exhibit irregular branches. Furthermore, the release and bioassay experiments show that monodisperse MTX/LDHs present good controlled-release and are more efficient in the suppression of the tumor cells. - Highlights: • Surfactants could be used to modify the dispersing state of MTX/LDHs hybrids. • Surfactants have great effect on the morphology of MTX/LDHs hybrids. • MTX/LDHs with good monodisperse degree are more efficient in the suppression of the tumor cells

  4. Methods to improve routine bioassay monitoring for freshly separated, poorly transported plutonium

    International Nuclear Information System (INIS)

    Several human cases involving inhalation of plutonium oxide at Hanford have shown clearance half-times from the lung that are much longer than the 500-day half-time recommended for class Y plutonium in Publication 30 of the International Commission on Radiological Protection(ICRP). The more tenaciously retained material is referred to as super class Y plutonium. The ability to detect super class Y plutonium by current routine bioassay measurements is shown to be poor. Pacific Northwest Laboratory staff involved in the Hanford Internal Dosimetry Program investigated four methods to se if improvements in routine monitoring of workers for fresh super class Y plutonium are feasible. The methods were lung counting, urine sampling, fecal sampling, and use of diethylenetriaminepentaacetate (DTPA) to enhance urinary excretion. Use of DTPA was determined to be not feasible. Routine fecal sampling was found to be feasible but not recommended. Recommendations were made to improve the detection level for routine annual urinalysis and routine annual lung counting. 12 refs., 9 figs., 7 tabs

  5. Comparative study on toxicity evaluation of anaerobically treated parboiled rice manufacturing wastewater through fish bioassay.

    Science.gov (United States)

    Giri, Dipti Ramesh; Singh, Ekta; Satyanarayan, Shanta

    2016-01-01

    Short term aquatic bioassay has been developed into a useful tool in water quality management. These tests give information on comparative toxicity of several compounds. The objective of this study was to evaluate the acute toxicity of raw and anaerobically treated effluents of the parboiled rice manufacturing industry. The acute toxicity test was carried out by using the fish Lebistes reticulatus under laboratory conditions. LC50 values for 24, 48, 72 and 96 hours ranged between 4.6 and 7.0% for the raw parboiled rice manufacturing wastewater. Two anaerobic fixed film fixed bed reactors and two different media matrices, i.e. UV stabilized Biopac media and Fugino spirals, were used for the treatment of parboiled rice mill wastewater. Effluents from these two reactors depicted LC50 values in the range of 68-88% and 62-78% for Biopac and Fugino spiral packed reactors, respectively. From the results, it is evident that anaerobically treated effluents from Biopac packed reactor is marginally better than Fugino spiral packed reactor. Results subjected to statistical evaluation depicted regression coefficient of more than 0.9 indicating good correlation between the mortality and effluent concentration.

  6. General Approach to the Immobilization of Glycoenzyme Chains Inside Calcium Alginate Beads for Bioassay.

    Science.gov (United States)

    Mallardi, Antonia; Angarano, Valeria; Magliulo, Maria; Torsi, Luisa; Palazzo, Gerardo

    2015-11-17

    A general method to obtain the efficient entrapment of mixtures of glycoenzymes in calcium alginate hydrogel is proposed in this paper. As a proof of principle, three glycoenzymes acting in series (trehalase, glucose oxidase, and horseradish peroxidase) have been coimmobilized in calcium alginate beads. The release of the enzymes from the hydrogel mesh (leakage) is avoided by exploiting the enzyme's aggregation induced by the concanavalin A. The aggregation process has been monitored by dynamic light scattering technique, while both enzyme encapsulation efficiency and leakage have been quantified spectrophotometrically. Obtained data show an encapsulation efficiency above 95% and a negligible leakage from the beads when enzyme aggregates are larger than 300 nm. Operational stability of "as prepared" beads has been largely improved by a coating of alternated shells of polycation poly(diallyldimethylammonium chloride) and of alginate. As a test for the effectiveness of the overall procedure, analytical bioassays exploiting the enzyme-containing beads have been developed for the optical determination of glucose and trehalose, and limit of detection values of 0.2 and of 40 μM, respectively, have been obtained.

  7. Bioassay-Guided Isolation of Neuroprotective Compounds from Uncaria rhynchophylla against Beta-Amyloid-Induced Neurotoxicity

    Directory of Open Access Journals (Sweden)

    Yan-Fang Xian

    2012-01-01

    Full Text Available Uncaria rhynchophylla is a component herb of many Chinese herbal formulae for the treatment of neurodegenerative diseases. Previous study in our laboratory has demonstrated that an ethanol extract of Uncaria rhynchophylla ameliorated cognitive deficits in a mouse model of Alzheimer’s disease induced by D-galactose. However, the active ingredients of Uncaria rhynchophylla responsible for the anti-Alzheimer’s disease activity have not been identified. This study aims to identify the active ingredients of Uncaria rhynchophylla by a bioassay-guided fractionation approach and explore the acting mechanism of these active ingredients by using a well-established cellular model of Alzheimer’s disease, beta-amyloid- (Aβ- induced neurotoxicity in PC12 cells. The results showed that six alkaloids, namely, corynoxine, corynoxine B, corynoxeine, isorhynchophylline, isocorynoxeine, and rhynchophylline were isolated from the extract of Uncaria rhynchophylla. Among them, rhynchophylline and isorhynchophylline significantly decreased Aβ-induced cell death, intracellular calcium overloading, and tau protein hyperphosphorylation in PC12 cells. These results suggest that rhynchophylline and isorhynchophylline are the major active ingredients responsible for the protective action of Uncaria rhynchophylla against Aβ-induced neuronal toxicity, and their neuroprotective effect may be mediated, at least in part, by inhibiting intracellular calcium overloading and tau protein hyperphosphorylation.

  8. Bioassay data and a retention-excretion model for systemic plutonium

    International Nuclear Information System (INIS)

    The estimation of systemic burdens from urinalyses has been the most common and useful method of quantifying occupational exposures to plutonium. Problems arise in using this technique, however, because of inadequate modeling of human retention, translocation, and excretion of this element. Present methods for estimating the systemic burden from urinalyses were derived to a large extent from patterns observed in the first few months after exposure, but there is now evidence that these same patterns do not persist over long periods. In this report we collect and discuss data needed for the interpretation of bioassay results for Pu. These data are used to develop a model that describes the movement, retention, and excretion of systemic Pu in the human body in terms of explicitly identified anatomical compartments. This model may be used in conjunction with existing models and/or case-specific information concerning the translocation of Pu from the respiratory or gastrointestinal tract or from wounds to the bloodstream. Attention is restricted to the behavior of Pu after it has gained access to the bloodstream. There remain significant uncertainties concerning some aspects of the movement of Pu, particularly its translocation from the liver. An attempt has been made to construct the model in such a way as to elucidate those areas needing further attention. 98 references, 18 figures, 16 tables

  9. Strategies of reducing the carcinogenic risk of cytostatic agents on the basis of bioassay evaluation.

    Science.gov (United States)

    Berger, M R

    1991-01-01

    This article described strategies that can be used to reduce the carcinogenic risk of cytostatic chemotherapy and summarizes our recent experimental results. Reduction of neoplasms caused by the carcinogenic potency inherent in cytostatic agents can be obtained. (A) by chemical modifications such as: (1) exchanging a chlorine atom in N, N'-bis-(2-chloroethyl)-N-nitrosourea (BCNU) in the chloroethyl group at N'-position for a hydroxyl group to form the less carcinogenic analog N-(2-chloroethyl)-N'-(2-hydroxyethyl)-N-nitrosourea (HECNU); (2) linking chlorambucil to the steroid prednisolone to obtain a conjugate (prednimustine) with distinctly lower carcinogenic potential than chlorambucil; (3) progressive ring halogenation of phenyl-triazenes to generate agents with decreased long-term toxic risk; (B) by replacing cyclophosphamide within the carcinogenic drug combination of cyclophosphamide, methotrexate and 5-fluorouracil (CMF) by vincristine to form the combination VMF which has no detectable carcinogenic potential; (C) by coadministration of cyclophosphamide and mesna to achieve a dose-related reduction of cyclophosphamide-induced urinary bladder carcinomas; (D) by administration of dinaline, a compound which reduces the spontaneous incidence of malignant tumors in rats. These examples demonstrate that the carcinogenic risk of single agents and drug combinations used for antineoplastic chemotherapy has successfully been reduced, as assessed in long-term bioassays. Such strategies should be considered in the treatment of patients with long life expectancy following cytotoxic chemotherapy.

  10. Detection of sputum eicosanoids in cystic fibrosis and in normal saliva by bioassay and radioimmunoassay.

    Science.gov (United States)

    Zakrzewski, J T; Barnes, N C; Piper, P J; Costello, J F

    1987-01-01

    We have measured arachidonic acid (AA) metabolites, leukotrienes (LTs) and prostanoids (Ps), in sputum of patients with cystic fibrosis (CF) and in normal saliva using bioassay and radioimmunoassay (RIA). Almost three times as much LTB4 is present in CF extracts compared with slow reacting substances (SRSs). Leukotrienes were not detected in normal saliva. In CF sputum there is a three-fold increase in the level of the vasodilator prostanoid prostaglandin E2 (PGE2) and the stable metabolite of prostacyclin, 6-oxo PGF1 alpha compared with the vasoconstrictor prostaglandin F2 alpha (PGF2 alpha) and thromboxane B2 (TxB2), a hydrolysis product of thromboxane A2. Experiments with BW755c (25 micrograms ml-1, n = 3) indicated that the majority of this activity was not produced during the extraction procedure. The detection of LTs and Ps in sputum of CF patients shows that these substances are present at biologically active concentrations and may contribute to the pathophysiology of this disease. PMID:3028454

  11. Bioassay measurements of individuals living near the US Department of Energy's Hanford Site in Washington State, Fall 1985

    International Nuclear Information System (INIS)

    The purpose of the bioassay measurements was to provide individuals, living within a specific area near the Hanford Site, information on the current levels of radionuclides in their bodies. The measurements included whole body counter (in vivo) examinations and urine sample analyses for detecting the presence of major radionuclides related to current and historical operations at Hanford. Notifications of the special measurements were sent by letter to 515 residences in north Franklin County. Eighty-nine individuals from 52 of the 515 residences requested and received whole body counts. Of these, 32 also provided urine samples. The measurements gave no evidence of unusual levels of radioactivity in any individual. The ability of bioassay measurements to detect the presence of radioactivity in an individual following an exposure is dependent on the quality of the measurement and the nature of the exposure. This report includes a discussion of the capability, under various circumstances, of the measurements that were provided

  12. Phytochemical and toxicity evaluation ofPhaleria macrocarpa (Scheff.) Boerl by MCF-7 cell line and brine shrimp lethality bioassay

    Institute of Scientific and Technical Information of China (English)

    Abul Kalam Azad; Wan Mohd Azizi Wan Sulaiman; Nushrat Khan Sunzida

    2016-01-01

    Objective:To evaluate the cytotoxicity ofPhaleria macrocarpa fruits extracts. Methods: The cytotoxicity test was carried out byin vitroMCF-7 cell line andin vivo brine shrimp lethality bioassay. Results: The preliminary phytochemical test showed the presence of alkaloids, carbohydrate, glycosides, saponin, terpene, steroids, phenols and flavonoids. TheMTT-assay results showed that the highest percentage of cell viability was 106.23% at concentration of 1.25µL and the lowest percentage was 13.04% at concentration of 10µL. Conclusions:TheMTT-assay and brine shrimp lethality bioassay results showed that the extract was non-toxic and it would be consumable as a herbal remedy.

  13. Phytochemical and toxicity evaluation of Phaleria macrocarpa (Scheff. Boerl by MCF-7 cell line and brine shrimp lethality bioassay

    Directory of Open Access Journals (Sweden)

    Abul Kalam Azad

    2016-01-01

    Full Text Available Objective: To evaluate the cytotoxicity of Phaleria macrocarpa fruits extracts. Methods: The cytotoxicity test was carried out by in vitro MCF-7 cell line and in vivo brine shrimp lethality bioassay. Results: The preliminary phytochemical test showed the presence of alkaloids, carbohydrate, glycosides, saponin, terpene, steroids, phenols and flavonoids. The MTT-assay results showed that the highest percentage of cell viability was 106.23% at concentration of 1.25 µL and the lowest percentage was 13.04% at concentration of 10 µL. Conclusions: The MTT-assay and brine shrimp lethality bioassay results showed that the extract was non-toxic and it would be consumable as a herbal remedy.

  14. Strain typing of classical scrapie by transgenic mouse bioassay using protein misfolding cyclic amplification to replace primary passage.

    Directory of Open Access Journals (Sweden)

    Katy E Beck

    Full Text Available According to traditional murine bioassay methodology, prions must be serially passaged within a new host before a stable phenotype, and therefore a strain, can be assigned. Prions often transmit with difficulty from one species to another; a property termed the transmission barrier. Transgenic mouse lines that over express prion protein (PrP genes of different species can circumvent the transmission barrier but serial passages may still be required, particularly if unknown strains are encountered. Here we sought to investigate whether protein misfolding cyclic amplification (PMCA, an in-vitro method of PrP(Sc replication, could be used to replace serial passage of VRQ/VRQ classical scrapie isolates undergoing strain typing in ovine transgenic tg338 mice. Two classical scrapie field isolates that do not readily transmit to wild-type mice underwent bioassay in tg338 mice pre- and post- PMCA and the phenotype of disease in inoculated mice was compared. For one of the sources investigated, the PMCA product gave rise to the same disease phenotypes in tg338 mice as traditional bioassay, as indicated by lesion profile, IHC analysis and Western blot, whilst the second source produced phenotypic characteristics which were not identical with those that arose through traditional bioassay. These data show that differences in the efficiency of PMCA as a strain-typing tool may vary between ovine classical scrapie isolates and therefore suggest that the ability of PMCA to replace serial passage of classical scrapie in tg338 mice may depend on the strain present in the initial source.

  15. Evaluation of the Antiproliferative Activity of the Leaves from Arctium lappa by a Bioassay-Guided Fractionation

    OpenAIRE

    Celso Vataru Nakamura; João Carlos Palazzo de Mello; Tânia Ueda-Nakamura; Cláudio Roberto Novello; Ivânia Teresinha Albrecht Schuquel; Cássia Mônica Sakuragui; Heinrich Luftmann; Samara Requena Nocchi; Karine Zanoli; Rafael Eidi Yamamoto; Fabio Bahls Machado

    2012-01-01

    Arctium lappa L. (Asteraceae) is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetat...

  16. The intact immature rodent uterotrophic bioassay: possible effects on assay sensitivity of vomeronasal signals from male rodents and strain differences.

    OpenAIRE

    Ashby, John; Owens, William; Odum, Jenny; Tinwell, Helen

    2003-01-01

    The vomeronasal organ in rodents is an important social and sexual signaling pathway. We have investigated whether the housing of intact immature females in close proximity to mature males would interfere with the sensitivity of the immature rodent uterotrophic bioassay as the result of vomeronasal signals transmitted by male urinary proteins. The hypothesis was that the proximity of males might induce early puberty, thereby increasing mean uterine weight and reducing the responsiveness of th...

  17. A systems approach to the management of arbuscular mycorrhiza: Bioassay and study of the impact of phosphorus supply

    OpenAIRE

    Kahiluoto, Helena

    2000-01-01

    The aim of this study was to find out whether utilization of arbuscular mycorrhiza (AM), in crop production in Nordic conditions, can be promoted through management of the cropping system. P fertilization was chosen as the pilot system to manage because it has a major effect on AM and because it is problematic from the viewpoint of sustainability. Our scant knowledge of AM functioning and its effects in the field is mainly due to the methodological problems of research. Therefore, a bioassay ...

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

    Science.gov (United States)

    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.

  19. Biological testing of sediment for the Olympia Harbor Navigation Improvement Project, 1988: Geoduck, amphipod, and echinoderm bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Ward, J.A.; Word, J.Q.; Antrim, L.D.

    1989-05-01

    The Olympia Harbor Navigation Improvement Project requires the dredging of approximately 330,000 cubic yards (cy) of sediment from the harbor entrance channel and 205,185 cy from the turning basin. Puget Sound Dredged Disposal Analysis (PSDDA) partial characterization studies were used to plan a full sediment characterization in which chemical analyses and biological testing of sediments evaluated the suitability of the dredged material for unconfined, open-water disposal. The US Army Corps of Engineers (COE), Seattle District, contracted with NOAA/NMFS, Environmental Conservation Division, to perform the chemical analysis and Microtox bioassay tests, and with the Battelle/Marine Sciences Laboratory (MSL) in Sequim to perform flow-through solid-phase bioassays utilizing juvenile (8 to 10 mm) geoduck clams, Panopea generosa, and static solid phase bioassays using the phoxocephalid amphipod, Rhepoxynius abronius, developing embryos and gametes of the purple sea urchin, Strongylocentrotus purpuratus, and the larvae of the Pacific oyster Crassostrea gigas. When the results of the biological tests were evaluated under PSDDA guidelines, it was found that all the tested sediment treatments from Olympia Harbor are suitable for unconfined open-water disposal. 14 refs., 12 figs., 3 tabs.

  20. Assessing soil ecotoxicity of methyl tert-butyl ether using earthworm bioassay; closed soil microcosm test for volatile organic compounds

    Energy Technology Data Exchange (ETDEWEB)

    An, Youn-Joo [Department of Environmental Science, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul 143-701 (Korea, Republic of)]. E-mail: anyjoo@konkuk.ac.kr

    2005-03-01

    An earthworm bioassay was conducted to assess ecotoxicity in methyl tert-butyl ether (MTBE)-amended soils. Ecotoxicity of MTBE to earthworms was evaluated by a paper contact method, natural field soil test, and an OECD artificial soil test. All tests were conducted in closed systems to prevent volatilization of MTBE out of test units. Test earthworm species were Perionyx excavatus and Eisenia andrei. Mortality and abnormal morphology of earthworms exposed to different concentrations of MTBE were examined. MTBE was toxic to both earthworm species and the severity of response increased with increasing MTBE concentrations. Perionyx excavatus was more sensitive to MTBE than Eisenia andrei in filter papers and two different types of soils. MTBE toxicity was more severe in OECD artificial soils than in field soils, possibly due to the burrowing behavior of earthworms into artificial soils. The present study demonstrated that ecotoxicity of volatile organic compounds such as MTBE can be assessed using an earthworm bioassay in closed soil microcosm with short-term exposure duration. - Earthworm bioassay can be a good protocol to assess soil ecotoxicity of volatile organic compounds such as MTBE.

  1. Duckweed (Lemna gibba) growth inhibition bioassay for evaluating the toxicity of olive mill wastes before and during composting.

    Science.gov (United States)

    Cayuela, M L; Millner, P; Slovin, J; Roig, A

    2007-08-01

    Two-phase olive mill waste (TPOMW) is considered the main problem confronting the modern oil extraction and processing industry. Composting has been recently proposed as a suitable method to treat TPOMW so that it is suitable for use in agriculture. In the work reported here, the Lemna gibba bioassay was tested to assess the toxicity of TPOMW before and during the composting process. The method was compared with the Lepidium sativum bioassay and with other chemical maturity indices traditionally reported in the literature. The L. gibba test proved to be a simple, sensitive, and accurate method to evaluate toxicity before and during the composting of TPOMW. Plant growth response was measured by two methods: counting the number of fronds (leaves) and measuring total frond area (TFA) with image analysis software. Compared to the counting of fronds (L. gibba) or seeds (L. sativum), the use of area-measuring software permitted a very rapid, unbiased and easy way of analysing the toxicity of TPOMW before and during composting. Although the accuracy of the frond count method was similar to the traditional cress seed test, data analysis showed that the TFA measurement method was statistically more accurate (significantly lower variance) than the frond count approach. Highly significant correlations were found between TFA and some important maturation indices commonly reported in literature indicating that the L. gibba bioassay can be a useful tool to determine the degree of maturity of TPOMW composts. PMID:17448522

  2. Plant bioassays to assess toxicity of textile sludge compost Bioensaios vegetais na avaliação da toxidade do composto de lodo têxtil

    OpenAIRE

    Ademir Sérgio Ferreira de Araújo; Regina Teresa Rosim Monteiro

    2005-01-01

    Composting of industrial wastes is increasing because of recycling requirements set on organic wastes. The evaluation of toxicity of these wastes by biological testing is therefore extremely important for screening the suitability of waste for land application. The toxicity of a textile sludge compost was investigated using seed germination and plant growth bioassays using soybean and wheat. Compost samples were mixed with water (seed germination bioassay) or nutrient solution (plant growth b...

  3. Comparison of methods of identifying Helicobacter hepaticus in B6C3F1 mice used in a carcinogenesis bioassay.

    Science.gov (United States)

    Fox, J G; MacGregor, J A; Shen, Z; Li, X; Lewis, R; Dangler, C A

    1998-05-01

    In a long-term rodent bioassay evaluating the carcinogenicity of triethanolamine, there was equivocal evidence of carcinogenic activity in male B6C3F1 mice, based on a marginal increase in the number of hepatocellular adenomas and hepatoblastomas. Interpretation was complicated by the presence of Helicobacter hepaticus in selected silver-stained liver sections which also had histological evidence of karyomegaly and oval cell hyperplasia. An increase in numbers of liver tumors, as evidence of carcinogenic activity, was also noted in female mice. However, H. hepaticus was not considered a complicating factor, because the livers of the female mice did not have histological features compatible with H. hepaticus infection. A retrospective analysis of 51 liver tissue samples from the original carcinogenicity study was conducted to determine the incidence of H. hepaticus infection and to evaluate different diagnostic approaches for assessing the presence of H. hepaticus in livers lacking characteristic lesions. In an initial evaluation of seven mice with liver tumors, argyrophilic bacteria resembling H. hepaticus were observed in liver sections, associated with characteristic liver lesions of hepatocytic karyomegaly and oval cell hyperplasia. Frozen liver tissue was available from four of these mice; all were confirmed to be infected with H. hepaticus by culture and PCR. In a larger subsequent analysis using frozen liver tissues from 44 mice without characteristic hepatic lesions, H. hepaticus-specific DNA was amplified from the livers of 21 of 44 of the mice (47%), compared to 14 of 44 of the mice (32%) having H. hepaticus cultured from their frozen liver tumors. The results of H. hepaticus culture and H. hepaticus-specific PCR concurred (i.e., both positive and negative results) in 84% of the cases. Microscopic detection of immunofluorescence-labeled or silver-stained bacteria in liver sections was relatively insensitive compared to either culture or PCR detection. This

  4. Adulticidal and larvicidal activity of Beauveria bassiana and Metarhizium anisopliae against housefly, Musca domestica (Diptera: Muscidae), in laboratory and simulated field bioassays.

    Science.gov (United States)

    Mishra, Sapna; Kumar, Peeyush; Malik, Anushree; Satya, Santosh

    2011-06-01

    The susceptibility of the adult and larval stage of housefly, Musca domestica L. (Diptera: Muscidae), to two entomopathogenic fungi, Metarhizium anisopliae (Metsch.) Sor. and Beauveria bassiana (Bals.) Vuill., was evaluated under laboratory and simulated field bioassays. Bioassays on adult houseflies were carried out at different conidial concentrations ranging from 10(3) to 10(9) conidia/ml in petri plate and minichamber assays. Absolute mortality was observed within 4-5 days at all the concentrations tested. M. anisopliae was found to be more effective with LC(50) of 6.75 × 10(7) conidia/ml compared with 1.21 × 10(8) conidia/ml of B. bassiana in petri plate bioassay. Similar trend was observed in minichamber bioassay. Larvicidal activity evaluated through petri plate bioassay also indicated that M. anisopliae was more effective larvicide with LC(50) of 4.1 × 10(8) conidia/ml as against 3.31 × 10(9) conidia/ml of B. bassiana. Larvicidal activity was further evaluated in simulated field condition of decaying waste matrix using dry conidial formulations (10(8) conidia/g) of both the fungi. Larval mortality obtained in this assay was 43% (B. bassiana) and 63% (M. anisopliae). Remarkably better performance of M. anisopliae as an adulticidal and larvicidal agent over B. bassiana in laboratory bioassays as well as simulated field conditions suggests that it may have good potential to become part of an integrated housefly control program.

  5. Cell bioassay for paralytic shellfish poisoning (PSP): comparison with postcolumn derivatization liquid chromatographic analysis and application to the monitoring of PSP in shellfish.

    Science.gov (United States)

    Hayashi, Rumiko; Saito, Hiroshi; Okumura, Masanao; Kondo, Fumio

    2006-01-25

    We performed a neuroblastoma cell (Neuro2a) culture assay modified slightly from a method reported previously to provide a simple and sensitive evaluation of paralytic shellfish poisoning (PSP) toxicity in shellfish. The cell bioassay was just as sensitive for C-toxins as for gonyautoxins. The sensitivity of our cell bioassay was 4 times that of the current standard mouse bioassay. Using the cell bioassay, we evaluated PSP toxicity in 361 shellfish samples collected from Mikawa Bay and Ise Bay, Aichi Prefecture, Japan, from April 1999-March 2002. The results were compared with those obtained in a postcolumn derivatization liquid chromatographic analysis. PSP toxins were detected in 236/361 samples by both assays, and there was a fairly good correlation (r = 0.9001, n = 236, p < 0.001) between the results from the two assays. We applied this cell bioassay when short-necked clams in the bay turned poisonous in 2001. The chronological changes in PSP toxicity in the short-necked clams were analyzed and compared with those of the cell density of poisonous plankton (Alexandrium tamarense) occurring in the bay. The PSP toxicity in shellfish peaked 2 weeks after the cell density reached a maximum. We recommend using the cell bioassay for routine monitoring of PSP toxicity in shellfish living in natural marine environments. PMID:16417278

  6. Use of a chemically induced-colon carcinogenesis-prone Apc-mutant rat in a chemotherapeutic bioassay

    Directory of Open Access Journals (Sweden)

    Yoshimi Kazuto

    2012-10-01

    Full Text Available Abstract Background Chemotherapeutic bioassay for colorectal cancer (CRC with a rat model bearing chemically-induced CRCs plays an important role in the development of new anti-tumor drugs and regimens. Although several protocols to induce CRCs have been developed, the incidence and number of CRCs are not much enough for the efficient bioassay. Recently, we established the very efficient system to induce CRCs with a chemically induced-colon carcinogenesis-prone Apc-mutant rat, Kyoto Apc Delta (KAD rat. Here, we applied the KAD rat to the chemotherapeutic bioassay for CRC and showed the utility of the KAD rat. Methods The KAD rat has been developed by the ENU mutagenesis and carries a homozygous nonsense mutation in the Apc gene (S2523X. Male KAD rats were given a single subcutaneous injection of AOM (20 mg/kg body weight at 5 weeks of age. Starting at 1 week after the AOM injection, they were given 2% DSS in drinking water for 7 days. Tumor-bearing KAD rats were divided into experimental and control groups on the basis of the number of tumors observed by endoscopy at week 8. The 5-fluorouracil (5-FU was administrated intravenously a dose of 50 or 75 mg/kg weekly at week 9, 10, and 11. After one-week interval, the 5-FU was given again at week 13, 14, and 15. At week 16, animals were sacrificed and tumor number and volume were measured macroscopically and microscopically. Results In total 48 tumors were observed in 27 KAD rats with a 100% incidence at week 8. The maximum tolerated dose for the KAD rat was 50 mg/kg of 5-FU. Macroscopically, the number or volume of tumors in the 5-FU treated rats was not significantly different from the control. Microscopically, the number of adenocarcinoma in the 5-FU treated rats was not significantly different (p Conclusion The use of the AOM/DSS-treated tumor-bearing KAD rats could shorten the experimental period and reduce the number of animals examined in the chemotherapeutic bioassay. The

  7. Use of a chemically induced-colon carcinogenesis-prone Apc-mutant rat in a chemotherapeutic bioassay

    International Nuclear Information System (INIS)

    Chemotherapeutic bioassay for colorectal cancer (CRC) with a rat model bearing chemically-induced CRCs plays an important role in the development of new anti-tumor drugs and regimens. Although several protocols to induce CRCs have been developed, the incidence and number of CRCs are not much enough for the efficient bioassay. Recently, we established the very efficient system to induce CRCs with a chemically induced-colon carcinogenesis-prone Apc-mutant rat, Kyoto Apc Delta (KAD) rat. Here, we applied the KAD rat to the chemotherapeutic bioassay for CRC and showed the utility of the KAD rat. The KAD rat has been developed by the ENU mutagenesis and carries a homozygous nonsense mutation in the Apc gene (S2523X). Male KAD rats were given a single subcutaneous injection of AOM (20 mg/kg body weight) at 5 weeks of age. Starting at 1 week after the AOM injection, they were given 2% DSS in drinking water for 7 days. Tumor-bearing KAD rats were divided into experimental and control groups on the basis of the number of tumors observed by endoscopy at week 8. The 5-fluorouracil (5-FU) was administrated intravenously a dose of 50 or 75 mg/kg weekly at week 9, 10, and 11. After one-week interval, the 5-FU was given again at week 13, 14, and 15. At week 16, animals were sacrificed and tumor number and volume were measured macroscopically and microscopically. In total 48 tumors were observed in 27 KAD rats with a 100% incidence at week 8. The maximum tolerated dose for the KAD rat was 50 mg/kg of 5-FU. Macroscopically, the number or volume of tumors in the 5-FU treated rats was not significantly different from the control. Microscopically, the number of adenocarcinoma in the 5-FU treated rats was not significantly different (p < 0.02) from that of the control. However, the volume of adenocarcinomas was significantly lower than in the control. Anticancer effect of the 5-FU could be obtained only after the 16 weeks of experimental period. The use of the AOM/DSS-treated tumor

  8. Chemically induced immunotoxicity in a medium-term multiorgan bioassay for carcinogenesis with Wistar rats

    International Nuclear Information System (INIS)

    A variety of chemicals can adversely affect the immune system and influence tumor development. The modifying potential of chemical carcinogens on the lymphoid organs and cytokine production of rats submitted to a medium-term initiation-promotion bioassay for carcinogenesis was investigated. Male Wistar rats were sequentially initiated with N-nitrosodiethylamine (DEN), N-methyl-N-nitrosourea (MNU), N-butyl-N-(4hydroxybutyl)nitrosamine (BBN), dihydroxy-di-n-propylnitrosamine (DHPN), and 1,2-dimethylhydrazine (DMH) during 4 weeks. Two initiated groups received phenobarbital (PB) or 2-acetylaminofluorene (2-AAF) for 25 weeks and two noninitiated groups received only PB or 2-AAF. A nontreated group was used as control. Lymphohematopoietic organs, liver, kidneys, lung, intestines, and Zymbal's gland were removed for histological analysis. Interleukin (IL)-2, IL-12, interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), IL-10, and transforming growth factor beta1 (TGF-β1) levels were determined by ELISA in spleen cell culture supernatants. At the fourth week, exposure to the initiating carcinogens resulted in cell depletion of the thymus, spleen and bone marrow, and impairment of IL-2, IL-12, and IFN-γ production. However, at the 30th week, no important alterations were observed both in lymphoid organs and cytokine production in the different groups. The results indicate that the initiating carcinogens used in the present protocol exert toxic effects on the lymphoid organs and affect the production of cytokines at the initiation step of carcinogenesis. This early and reversible depression of the immune surveillance may contribute to the survival of initiated cells facilitating the development of future neoplasia

  9. Bioassay analysis of efficacy of phytoremediation in decontamination of coal mine effluent.

    Science.gov (United States)

    Bharti, Sandhya; Banerjee, Tarun Kumar

    2013-06-01

    Phytoremediation efficacy of Lemna minor and Azolla pinnata in decontaminating metals from coal mine effluent (CME) was analyzed using bioassays. Catfish Heteropneustes fossilis were exposed to both the phytoremediated CMEs for the metal bioaccumulation analysis and biochemical alteration in seven vital tissues. Gross concentration of metals accumulated in liver, kidneys, air breathing organs (ABO), skin and muscle were greater in fish exposed to A. pinnata remediated CME (AP-CME) than those exposed to L. minor remediated CME (LP-CME). Total protein concentrations of all the tissues were greater in fish exposed to LP-CME than to AP-CME. Glycogen concentrations were greater in muscle, brain, ABO and skin of LP-CME exposed fish. In remaining tissues (liver, kidneys and gills) concentrations of glycogen were more in AP-CME exposed ones. Total lipid and total DNA concentrations were greater in most of the tissues of fish exposed to LP-CME than to AP-CME. The total RNA concentrations were elevated only in muscle, liver, kidneys and brain of LP-CME exposed fish; in rest of the tissues (gills, ABO and skin) it was greater in AP-CME exposed fish. The values of condition factor (K) and organosomatic index (OSI) of fish exposed to LP-CME and AP-CME were insignificant to those of wild fish. However, the improvements in the biomolecules concentration of tissues of fish exposed to either of the phytoremediated effluent were not equivalent to their concentration in the wild fish. Thus, decontamination of CME by either of these macrophytes was not complete and prolonged exposure of even phytoremediated CMEs exerts deleterious effects on the fish. PMID:23566881

  10. Application of a canine {sup 238}Pu dosimetry model to human bioassay data

    Energy Technology Data Exchange (ETDEWEB)

    Hickman, A.W. Jr. [Florida Univ., Gainesville, FL (United States)

    1991-08-01

    Associated with the use of 2{sup 238}Pu in thermoelectric power sources for space probes and power supplies for cardiac devices is the potential for human exposure to {sup 238}Pu, primarily by inhalation. In the event of human internal exposure, a means is needed for assessing the level of intake and calculating radiation doses. Several bioassay/dosimetry models have been developed for {sup 239}Pu. However, results from studies with laboratory animals have indicated that the biokinetics, and therefore the descriptive models, of {sup 238}Pu are significantly different from those for {sup 239}Pu. A canine model accounting for these differences has been applied in this work to urinary excretion data from seven humans occupationally exposed to low levels of an insoluble {sup 238}Pu compound. The modified model provides a good description of the urinary excretion kinetics observed in the exposed humans. The modified model was also used to provide estimates of the initial intakes of {sup 238}Pu for the seven individuals; these estimates ranged from 4.5 nCi (170 Bq) to 87 nCi (3200 Bq). Autopsy data on the amount and distribution of {sup 238}Pu retained in the organs may be used in the future to validate or refute both these estimates and the assumptions used to formulate the human model. Modification of the human model to simulate an injection exposure to {sup 239}Pu gave patterns of retention in the organs and urinary excretion comparable to those seen previously in humans; further modification of the model using fecal data (unavailable for the subjects of this study) is indicated.

  11. Allelopathy in a leguminous mangrove plant, Derris indica: protoplast co-culture bioassay and rotenone effect.

    Science.gov (United States)

    Inoue, Aya; Mori, Daisuke; Minagawa, Reiko; Fujii, Yoshiharu; Sasamoto, Hamako

    2015-05-01

    To investigate allelopathic activity of a leguminous mangrove plant, Derris indica, the 'Protoplasts Co-culture Method' for bioassay of allelopathy was developed using suspension culture. A suspension culture was induced from immature seed and sub-cultured in Murashige and Skoog's (MS) basal medium containing 10 μM each of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (BA). The protoplasts were isolated using the separate wells method with 2% each of Cellulase RS, Driselase 20 and Macerozyme R10 in 0.4 M mannitol solution. Protoplast cultures of D. indica revealed that high concentrations of cytokinins, BA and thidiazuron, were effective for cell divisions. The co-cultures of D. indica protoplasts with recipient lettuce protoplasts using 96 multi-well culture plates were performed in MS basal medium containing 0.4 M mannitol solution and 1 μM 2,4-D and 0.1 μM BA. The protoplast density of D. indica used in co-culturing varied from 6 x 10(3) - 10(5) / mL. Very strong inhibitory allelopathic effects of D. indica protoplasts on lettuce protoplast growth were found. A similar strong inhibitory allelopathic activity of dried young leaves on lettuce seedling growth was also observed by using the sandwich method. Rotenone, which is a component of Derris root, dissolved in DMSO, was highly inhibitory on the growth of lettuce protoplasts in culture and this could be one of the causes of the strong allelopathic activity of D. indica.

  12. Facile synthesis of methotrexate intercalated layered double hydroxides: particle control, structure and bioassay explore.

    Science.gov (United States)

    Tian, De-Ying; Liu, Zhen-Lei; Li, Shu-Ping; Li, Xiao-Dong

    2014-12-01

    To study the influence of particle size on drug efficacy and other properties, a series of methotrexate intercalated layered double hydroxides (MTX/LDHs) were synthesized through the traditional coprecipitation method, using a mixture of water and polyethylene glycol (PEG-400) as the solvent. To adjust the particle size of MTX/LDHs, the dropping way, the volume ratio of water to PEG-400 and different hydrothermal treatment time changed accordingly, and the results indicate that the particle size can be controlled between 90 and 140 nm. Elemental C/H/N and inductive coupled plasma (ICP) analysis indicated that different synthesis conditions almost have no effect on the compositions of the nanohybrids. X-ray diffraction (XRD) patterns manifested the successful intercalation of MTX anions into the LDH interlayers, and it's also found out that different volume ratios of water to PEG-400 and variable dropping way can affect the crystallinity of the final samples, i.e., the volume ratio of 3:1 and pH decreasing are proved to be optimum conditions. Furthermore, both antiparallel monolayer and bilayers adopting different orientations are suggested for four samples from XRD results. Fourier transform infrared spectroscopy (FTIR) investigations proved the coexistence of CO3(2-) and MTX anions in the interlayer of the nanohybrids. MTX/LDH particles exhibited hexagonal platelet morphology with round corner and different dropping ways can affect the morphology greatly. Moreover, a DSC study indicated that longer time treatment can weaken the bond between the MTX anions and LDH layers. The kinetic release profiles told us that larger MTX/LDH particles have enhanced the ability of LDH layers to protect interlayer molecules. At last, the bioassay study indicated that the nanohybrids with larger diameters have higher tumor suppression efficiency. PMID:25491832

  13. The sensitivity of an hydroponic lettuce root elongation bioassay to metals, phenol and wastewaters.

    Science.gov (United States)

    Park, Jihae; Yoon, Jeong-hyun; Depuydt, Stephen; Oh, Jung-Woo; Jo, Youn-min; Kim, Kyungtae; Brown, Murray T; Han, Taejun

    2016-04-01

    The root elongation bioassay is one of the most straightforward test methods used for environmental monitoring in terms of simplicity, rapidity and economy since it merely requires filter paper, distilled water and Petri dishes. However, filter paper as a support material is known to be problematic as it can reduce the sensitivity of the test. The newly developed hydroponic method reported here differs from the conventional root elongation method (US EPA filter paper method) in that no support material is used and the exposure time is shorter (48 h in this test versus 120 h in the US EPA test). For metals, the hydroponic test method was 3.3 (for Hg) to 57 (for Cu) times more sensitive than the US EPA method with the rank orders of sensitivity, estimated from EC50 values, being Cu≥Cd>Ni≥Zn≥Hg for the former and Hg≥Cu≥Ni≥Cd≥Zn for the latter methods. For phenol, the results did not differ significantly; EC50 values were 124 mg L(-1) and 108-180 mg L(-1) for the hydroponic and filter paper methods, respectively. Lettuce was less sensitive than daphnids to wastewaters, but the root elongation response appears to be wastewater-specific and is especially sensitive for detecting the presence of fluorine. The new hydroponic test thus provides many practical advantages, especially in terms of cost and time-effectiveness requiring only a well plate, a small volume of distilled water and short exposure period; furthermore, no specialist expertise is required. The method is simpler than the conventional EPA technique in not using filter paper which can influence the sensitivity of the test. Additionally, plant seeds have a long shelf-life and require little or no maintenance. PMID:26748376

  14. The sensitivity of an hydroponic lettuce root elongation bioassay to metals, phenol and wastewaters.

    Science.gov (United States)

    Park, Jihae; Yoon, Jeong-hyun; Depuydt, Stephen; Oh, Jung-Woo; Jo, Youn-min; Kim, Kyungtae; Brown, Murray T; Han, Taejun

    2016-04-01

    The root elongation bioassay is one of the most straightforward test methods used for environmental monitoring in terms of simplicity, rapidity and economy since it merely requires filter paper, distilled water and Petri dishes. However, filter paper as a support material is known to be problematic as it can reduce the sensitivity of the test. The newly developed hydroponic method reported here differs from the conventional root elongation method (US EPA filter paper method) in that no support material is used and the exposure time is shorter (48 h in this test versus 120 h in the US EPA test). For metals, the hydroponic test method was 3.3 (for Hg) to 57 (for Cu) times more sensitive than the US EPA method with the rank orders of sensitivity, estimated from EC50 values, being Cu≥Cd>Ni≥Zn≥Hg for the former and Hg≥Cu≥Ni≥Cd≥Zn for the latter methods. For phenol, the results did not differ significantly; EC50 values were 124 mg L(-1) and 108-180 mg L(-1) for the hydroponic and filter paper methods, respectively. Lettuce was less sensitive than daphnids to wastewaters, but the root elongation response appears to be wastewater-specific and is especially sensitive for detecting the presence of fluorine. The new hydroponic test thus provides many practical advantages, especially in terms of cost and time-effectiveness requiring only a well plate, a small volume of distilled water and short exposure period; furthermore, no specialist expertise is required. The method is simpler than the conventional EPA technique in not using filter paper which can influence the sensitivity of the test. Additionally, plant seeds have a long shelf-life and require little or no maintenance.

  15. Rolling-based direct-transfer printing: A process for large-area transfer of micro- and nanostructures onto flexible substrates

    Science.gov (United States)

    Grierson, D. S.; Flack, F. S.; Lagally, M. G.; Turner, K. T.

    2016-09-01

    A rolling-based printing approach for transferring arrays of patterned micro- and nano-structures directly from rigid fabrication substrates onto flexible substrates is presented. Transfer-printing experiments show that the new process can achieve high-yield and high-fidelity transfer of silicon nanomembrane components with diverse architectures to polyethylene terephthalate substrates over chip-scale areas (>1 × 1 cm2) in process are investigated through finite element simulations of the contact and transfer process. These mechanics models provide guidance for controlling the contact area and strain in the flexible substrate during transfer, both of which are key for achieving reproducible and controlled component transfer over large areas.

  16. Effects of multiple conformers per compound upon 3-D similarity search and bioassay data analysis

    Directory of Open Access Journals (Sweden)

    Kim Sunghwan

    2012-11-01

    Full Text Available Abstract Background To improve the utility of PubChem, a public repository containing biological activities of small molecules, the PubChem3D project adds computationally-derived three-dimensional (3-D descriptions to the small-molecule records contained in the PubChem Compound database and provides various search and analysis tools that exploit 3-D molecular similarity. Therefore, the efficient use of PubChem3D resources requires an understanding of the statistical and biological meaning of computed 3-D molecular similarity scores between molecules. Results The present study investigated effects of employing multiple conformers per compound upon the 3-D similarity scores between ten thousand randomly selected biologically-tested compounds (10-K set and between non-inactive compounds in a given biological assay (156-K set. When the “best-conformer-pair” approach, in which a 3-D similarity score between two compounds is represented by the greatest similarity score among all possible conformer pairs arising from a compound pair, was employed with ten diverse conformers per compound, the average 3-D similarity scores for the 10-K set increased by 0.11, 0.09, 0.15, 0.16, 0.07, and 0.18 for STST-opt, CTST-opt, ComboTST-opt, STCT-opt, CTCT-opt, and ComboTCT-opt, respectively, relative to the corresponding averages computed using a single conformer per compound. Interestingly, the best-conformer-pair approach also increased the average 3-D similarity scores for the non-inactive–non-inactive (NN pairs for a given assay, by comparable amounts to those for the random compound pairs, although some assays showed a pronounced increase in the per-assay NN-pair 3-D similarity scores, compared to the average increase for the random compound pairs. Conclusion These results suggest that the use of ten diverse conformers per compound in PubChem bioassay data analysis using 3-D molecular similarity is not expected to increase the separation of non

  17. Contact Bioassays with Phenoxybenzyl and Tetrafluorobenzyl Pyrethroids against Target-Site and Metabolic Resistant Mosquitoes.

    Directory of Open Access Journals (Sweden)

    Sebastian Horstmann

    Full Text Available Mosquito strains that exhibit increased tolerance to the chemical class of compounds with a sodium channel modulator mode of action (pyrethroids and pyrethrins are typically described as "pyrethroid resistant". Resistance to pyrethroids is an increasingly important challenge in the control of mosquito-borne diseases, such as malaria or dengue, because one of the main interventions (the distribution of large numbers of long-lasting insecticide-treated bed nets currently relies entirely on long-lasting pyrethroids. Increasing tolerance of target insects against this class of insecticides lowers their impact in vector control. The current study suggests that the level of metabolic resistance depends on the structure of the molecule and that structurally different compounds may still be effective because detoxifying enzymes are unable to bind to these uncommon structures.Treated surface contact bioassays were performed on susceptible Aedes aegypti, East African knockdown resistance (kdr Anopheles gambiae (strain RSP-H and metabolically resistant Anopheles funestus (strain FUMOZ-R with different pyrethroids, such as cypermethrin, ß-cyfluthrin, deltamethrin, permethrin and transfluthrin (alone and in combination with the synergist piperonyl butoxide. The nonfluorinated form of transfluthrin was also assessed as a single agent and in combination with piperonyl butoxide.Although the dosages for pyrethroids containing a phenoxybenzyl moiety have exhibited differences in terms of effectiveness among the three tested mosquito species, the structurally different transfluthrin with a polyfluorobenzyl moiety remained active in mosquitoes with upregulated P450 levels. In trials with transfluthrin mixed with piperonyl butoxide, the added synergist exhibited no efficacy-enhancing effect.The results of this study suggest that transfluthrin has the potential to control P450-mediated metabolically resistant mosquitoes because the structural formula of

  18. Rapid bioassay-guided screening of toxic substances in vegetable oils that shorten the life of SHRSP rats

    Directory of Open Access Journals (Sweden)

    Lewandowski Paul

    2010-02-01

    Full Text Available Abstract It has been consistently reported that vegetable oils including canola oil have a life shortening effect in Stroke-Prone Spontaneously Hypertensive Rats (SHRSP and this toxic effect is not due to the fatty acid composition of the oil. Although it is possible that the phytosterol content or type of phytosterol present in vegetable oils may play some role in the life shortening effect observed in SHRSP rats this is still not completely resolved. Furthermore supercritical CO2 fractionation of canola oil with subsequent testing in SHRSP rats identified safe and toxic fractions however, the compounds responsible for life shortening effect were not characterised. The conventional approach to screen toxic substances in oils using rats takes more than six months and involves large number of animals. In this article we describe how rapid bioassay-guided screening could be used to identify toxic substances derived from vegetable oils and/or processed foods fortified with vegetable oils. The technique incorporates sequential fractionation of oils/processed foods and subsequent treatment of human cell lines that can be used in place of animal studies to determine cytotoxicity of the fractions with structural elucidation of compounds of interest determined via HPLC-MS and GC-MS. The rapid bioassay-guided screening proposed would require two weeks to test multiple fractions from oils, compared with six months if animal experiments were used to screen toxic effects. Fractionation of oil before bio-assay enhances the effectiveness of the detection of active compounds as fractionation increases the relative concentration of minor components.

  19. Repositioning organohalogen drugs: a case study for identification of potent B-Raf V600E inhibitors via docking and bioassay.

    Science.gov (United States)

    Li, Yisu; Guo, Binbin; Xu, Zhijian; Li, Bo; Cai, Tingting; Zhang, Xinben; Yu, Yuqi; Wang, Heyao; Shi, Jiye; Zhu, Weiliang

    2016-01-01

    Drug repositioning has been attracting increasingly attention for its advantages of reducing costs and risks. Statistics showed that around one quarter of the marketed drugs are organohalogens. However, no study has been reported, to the best of our knowledge, to aim at efficiently repositioning organohalogen drugs, which may be attributed to the lack of accurate halogen bonding scoring function. Here, we present a study to show that two organohalogen drugs were successfully repositioned as potent B-Raf V600E inhibitors via molecular docking with halogen bonding scoring function, namely D(3)DOCKxb developed in our lab, and bioassay. After virtual screening by D(3)DOCKxb against the database CMC (Comprehensive Medicinal Chemistry), 3 organohalogen drugs that were predicted to form strong halogen bonding with B-Raf V600E were purchased and tested with ELISA-based assay. In the end, 2 of them, rafoxanide and closantel, were identified as potent inhibitors with IC50 values of 0.07 μM and 1.90 μM, respectively, which are comparable to that of vemurafenib (IC50: 0.17 μM), a marketed drug targeting B-Raf V600E. Single point mutagenesis experiments confirmed the conformations predicted by D(3)DOCKxb. And comparison experiment revealed that halogen bonding scoring function is essential for repositioning those drugs with heavy halogen atoms in their molecular structures. PMID:27501852

  20. Evaluation of Baffle Fixes Film up Flow Sludge Blanket Filtration (BFUSBF System in Treatment of Wastewaters from Phenol and 2,4-Dinitrophenol Using Daphnia Magna Bioassay

    Directory of Open Access Journals (Sweden)

    Mohammad Javad Ghannadzadeh

    2016-02-01

    Full Text Available Background: Phenol and nitrophenol are common compounds found in different types of industrial wastewater known as serious threats to human health and natural environment. In this study, Daphnia magna was used to evaluate the effectiveness of "baffle fixes film up flow sludge blanket filtration" (BFUSBF system in elimination of phenolic compounds from water. Methods: D. magna cultures were used as toxicity index of phenol and 2,4-DNP mixtures after treatment by a pilot BFUSBF system which consisted of baffle in anoxic section and biofilm in aerobic sections. Initial concentrations were 312 mg/L phenol and 288 mg/L 2,4-dinitrophenol (2,4-DNP. Results: Bioassay tests showed that D. magna was influenced by the toxicity of phenol and 2,4 DNP mixtures. The comparison between the toxicity of initial phenol and 2,4-DNP mixtures and the output toxic unit (TU derived from BFUSBF treatment system showed that the TU of the effluent from BFUSBF reactor was much lower than that of the solution that entered the reactor. Conclusion: Based on the acute toxicity test, BFUSBF process could reduce phenol and 2,4-DNP in aqueous solutions. Therefore, it is possible to use BFUSBF process as an appropriate treatment option for wastewaters containing phenolic compounds.

  1. Development of standardized bioassay protocols for the toxicity assessment of waste, manufactured products, and effluents in Latin America: Venezuela, a Case Study

    International Nuclear Information System (INIS)

    The present status of the toxicity assessment of industrial products in Latin America is well below North America/EC standards. As an example, most of Latin America regulatory laws regarding effluent discharge are still based upon concentration limits of certain major pollutants, and BOD/COD measurements; no reference is made to the necessity of aquatic bioassay toxicity data. Aware of this imperative need, the Venezuelan Petroleum Industry (PDVSA), through its R ampersand D Corporative branch (INTEVEP) gave priority to the development of standardized acute/sublethal toxicity test protocols as sound means of evaluating their products and wastes. Throughout this presentation, the Venezuelan case will be studied, showing strategies undertaken to accelerate protocol development. Results will show the assessment of 14 different protocols encompassing a variety of species of aquatic/terrestrial organisms, and a series of toxicity test endpoints including mortality, reproductive, biological and immunological measurements, most of which are currently in use or being developed. These protocols have already yielded useful results in numerous cases where toxicity assessment was required, including evaluations of effluent, oil dispersants, drilling fluids, toxic wastes, fossil fuels and newly developed products. The Venezuelan case demonstrates that the integration of Industry, Academia and Government, which is an essential part of SETAC's philosophy, is absolutely necessary for the successful advancement of environmental scientific/regulatory issues

  2. Contact allergy to oak moss: search for sensitizing molecules using combined bioassay-guided chemical fractionation, GC-MS, and structure-activity relationship analysis.

    Science.gov (United States)

    Bernard, Guillaume; Giménez-Arnau, Elena; Rastogi, Suresh Chandra; Heydorn, Siri; Johansen, Jeanne Duus; Menné, Torkil; Goossens, An; Andersen, Klaus; Lepoittevin, Jean-Pierre

    2003-11-01

    In addition to pure synthetic fragrance materials several natural extracts are still in use in the perfume industry. Among them oak moss absolute, prepared from the lichen Evernia prunastri (L.) Arch., is considered a major contact sensitizer and is therefore included in the fragrance mix used for diagnosing perfume allergy. The process of preparing oak moss absolute has changed during recent years and, even though several potential sensitizers have been identified from former benzene extracts, its present constituents and their allergenic status are not clear. In the study reported here, we applied a method developed for the identification of contact allergens present in natural complex mixtures to oak moss absolute. The method is based on the combination of bioassay-guided chemical fractionation, gas chromatography-mass spectrometry analysis and structure-activity relationship studies. Our first results showed that atranol and chloroatranol, formed by transesterification and decarboxylation of the lichen depsides, atranorin and chloroatranorin, during the preparation of oak moss absolute, are strong elicitants in most patients sensitized to oak moss. Methyl-beta-orcinol carboxylate, a depside degradation product and the most important monoaryl derivative of oak moss from an olfactory standpoint, was also found to elicit a reaction in most patients. PMID:13680271

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

    International Nuclear Information System (INIS)

    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. - In situ bioassays with Chironomus riparius larvae can be a suitable tool to monitor restoration efficiency after a long time of metallic sediment contamination

  4. Selection of a bioassay battery to assess toxicity in the affluents and effluents of three water-treatment plants

    Directory of Open Access Journals (Sweden)

    Paola Bohórquez-Echeverry

    2012-08-01

    Full Text Available The assessment of water quality includes the analysis of both physical-chemical and microbiological parameters. However,none of these evaluates the biological effect that can be generated in ecosystems or humans. In order to define the most suitable organismsto evaluate the toxicity in the affluent and effluent of three drinking-water treatment plants, five acute toxicity bioassays were used,incorporating three taxonomic groups of the food chain. Materials and methods. The bioassays used were Daphnia magna and Hydraattenuata as animal models, Lactuca sativa and Pseudokirchneriella subcapitata as plant models, and Photobacterium leioghnathi asbacterial model. To meet this objective, selection criteria of the organisms evaluated and cluster analysis were used to identify the mostsensitive in the affluent and effluent of each plant. Results. All organisms are potentially useful in the assessment of water quality bymeeting four essential requirements and 17 desirable requirements equivalent to 100% acceptability, except P. leioghnathi which doesnot meet two essential requirements that are the IC50 for the toxic reference and the confidence interval. The animal, plant and bacterialmodels showed different levels of sensitivity at the entrance and exit of the water treatment systems. Conclusions. H. attenuata, P.subcapitata and P. leioghnathi were the most effective organisms in detecting toxicity levels in the affluents and D. magna, P. subcapitataand P. leioghnathi in the effluents.

  5. Bioassay-Guided Fractionation of a Leaf Extract from Combretum mucronatum with Anthelmintic Activity: Oligomeric Procyanidins as the Active Principle

    Directory of Open Access Journals (Sweden)

    Verena Spiegler

    2015-08-01

    Full Text Available Combretum mucronatum Schumach. & Thonn. is a medicinal plant widely used in West African traditional medicine for wound healing and the treatment of helminth infections. The present study aimed at a phytochemical characterization of a hydroalcoholic leaf extract of this plant and the identification of the anthelmintic compounds by bioassay-guided fractionation. An EtOH-H2O (1:1 extract from defatted leaves was partitioned between EtOAc and H2O. Further fractionation was performed by fast centrifugal partition chromatography, RP18-MPLC and HPLC. Epicatechin (1, oligomeric proanthocyanidins (OPC 2 to 10 (mainly procyanidins and flavonoids 11 to 13 were identified as main components of the extract. The hydroalcoholic extract, fractions and purified compounds were tested in vitro for their anthelmintic activity using the model nematode Caenorhabditis elegans. The bioassay-guided fractionation led to the identification of OPCs as the active compounds with a dose-dependent anthelmintic activity ranging from 1 to 1000 μM. Using OPC-clusters with a defined degree of polymerization (DP revealed that a DP ≥ 3 is necessary for an anthelmintic activity, whereas a DP > 4 does not lead to a further increased inhibitory effect against the helminths. In summary, the findings rationalize the traditional use of C. mucronatum and provide further insight into the anthelmintic activity of condensed tannins.

  6. Comparative surfactant reactivity of canine and human stratum corneum: a plea for the use of the corneosurfametry bioassay.

    Science.gov (United States)

    Goffin, V; Fontaine, J; Piérard, G E

    1999-01-01

    Comparative dermatology has paid little attention to the physiopathology of the stratum corneum. In this study, we investigated the responses of human and canine horny layers to marketed animal wash products by using the corneosurfametry bioassay. Previous work has shown that, with increasing surfactant aggressiveness to the stratum corneum, the colorimetric index of mildness (CIM) decreases, while both the corneosurfametry index (CSMI) and the overall difference in corneosurfametry (ODC) increase. In the present study, stratum corneum reactivity to wash products and inter-individual variability were significantly higher in humans than in dogs. For the three corneosurfametry variables, linear correlations were found between data gathered in the two panel groups. In conclusion, this pilot study suggests that mean stratum corneum reactivity to surfactants is stronger in humans than in dogs. Inter-individual variation, indicative of sensitive skin, also appears to be broader in humans. As a consequence, data gathered from dogs by using the corneosurfametry bioassay cannot be extrapolated to humans. Such variation between species could be important in the assessment of product safety and in supporting claims for mildness.

  7. Bioassay-guided extraction of crude fucose-containing sulphated polysaccharides from Sargassum fusiforme with response surface methodology

    Science.gov (United States)

    Fu, Zhifei; Li, Haihua; Liu, Hongbing; Hu, Shuman; Li, Yueying; Wang, Mengxue; Guan, Huashi

    2016-06-01

    The response surface methodology (RSM) combined with bioassays was employed to optimize the extraction process of crude fucose-containing sulphated polysaccharides (cFCSP) from Sargassum fusiforme. The central composite design (CCD) was used with four variables, five levels, and four responses. The four variables were pH value of hydrochloric acid solution, extraction temperature (°C), ratio of liquid to raw material (mL g-1), and extraction time (h), respectively. Chemical and bioassay indices were used in combination as the response parameters, which included the yield of cFCSP, fucose content, proliferation rate of spleen cells, and lipopolysaccharide-induced proliferation of splenocytes. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis, and examined using the appropriate statistical methods. The best extraction conditions were as follows: the pH value of hydrochloric acid solution was 3.50; the extraction temperature was 100°C; the ratio of liquid to raw material was 15.00 mL g-1 and the extraction time was 2.50 h. The experimental yield was close to the predicted from the model. The extract could promote spleen lymphocyte proliferation, especially the lipopolysaccharide-induced lymphocyte proliferation in vitro, which suggested that its immunomodulatory effect on B lymphocytes. Therefore, cFCSP extracted from S. fusiforme could be utilized as an immunostimulant in functional foods and pharmaceutical industry in future.

  8. Development of bioassay for pathogenecity testing of Ureaplasma urealyticum as part of host-pathogen communication

    Directory of Open Access Journals (Sweden)

    Purnomo Soeharso

    2005-12-01

    Full Text Available Bioassay of Ureaplasma urealyticum is necessary for detection as well as determination of pathogenic factors in order to understand the pathogenesis of diseases associate with ureaplasma infection. Cultivation and verification of ureaplasma is the first step of this study in the purpose of discovering sensitive method for ureaplasma detection. Cultivation of ureaplasma either in liquid or in solid media are able to detect the existence of ureaplasma in samples analyzed. However, application of PCR using specific primers to be compatible with urease gene (ure would confirm the presence of ureaplasma. The pathogenicity of ureaplasma is potentially monitored using reporter gene as a marker for gene expression. IceC was chosen as reporter gene for ureaplasma pathogenic determination as the gene has great sensitivity, easily detectable and quantitated in simple method of ice nucleation assay. Transposon 916 (Tn916 was selected as a vector for iceC gene to transform ureaplasma. The application of recombinant Tn916-iceC which is considered as pUI, allow detection of ureaplasma activities when transform ureaplasma is tested by ice nucleation assay. It was expected that ureaplasma transformation is the manifestation of mutagenesis which interfere genes responsible for bacterial pathogenicity, in order pathogenesis of bacterial infection to be analyzed accurately. IgA1 protease is considered to be an important factor for ureaplasma pathogenicity as the enzyme is required for successful colonization. Identification of iga gene and  determination of IgA1 protease activity are important for understanding the pathogenesis of ureaplasma infection. Putative iga gene of Mycoplasma genitalium was used as a reference to identify the presence of iga nucleotide sequence in U. urealyticum. Convincing evidence were obtained after PCR amplification of ureaplasma DNA using primers designed to be compatible with putative iga gene of M. genitalium followed by the

  9. Investigations on sediment toxicity of German rivers applying a standardized bioassay battery.

    Science.gov (United States)

    Hafner, Christoph; Gartiser, Stefan; Garcia-Käufer, Manuel; Schiwy, Sabrina; Hercher, Christoph; Meyer, Wiebke; Achten, Christine; Larsson, Maria; Engwall, Magnus; Keiter, Steffen; Hollert, Henner

    2015-11-01

    River sediments may contain a huge variety of environmental contaminants and play a key role in the ecological status of aquatic ecosystems. Contaminants adsorbed to sediments and suspended solids may contribute directly or after remobilization to an adverse ecological and chemical status of surface water. In this subproject of the joint research project DanTox, acetonic Soxhlet extracts from three German river sediments from the River Rhine (Altrip and Ehrenbreitstein with moderate contamination) and River Elbe (Veringkanal Hamburg heavily contaminated) were prepared and redissolved in dimethyl sulfoxide (DMSO). These extracts were analyzed with a standard bioassay battery with organisms from different trophic levels (bacteria, algae, Daphnia, fish) as well as in the Ames test and the umuC test for bacterial mutagenicity and genotoxicity according to the respective OECD and ISO guidelines. In total, 0.01% (standard) up to 0.25% (only fish embryo test) of the DMSO sediment extract was dosed to the test systems resulting in maximum sediment equivalent concentrations (SEQ) of 2 up to 50 g l(-1). The sediment of Veringkanal near Hamburg harbor was significantly more toxic in most tests compared to the sediment extracts from Altrip and Ehrenbreitstein from the River Rhine. The most toxic effect found for Veringkanal was in the algae test with an ErC50 (72 h) of 0.00226 g l(-1) SEQ. Ehrenbreitstein and Altrip samples were about factor 1,000 less toxic. In the Daphnia, Lemna, and acute fish toxicity tests, no toxicity at all was found at 2 g l(-1) SEQ. corresponding to 0.01% DMSO. Only when increasing the DMSO concentration the fish embryo test showed a 22-fold higher toxicity for Veringkanal than for Ehrenbreitstein and Altrip samples, while the toxicity difference was less evident for the Daphnia test due to the overlaying solvent toxicity above 0.05% dimethyl sulfoxide (DMSO). The higher toxicities observed with the Veringkanal sample are supported by the PAH and PCB

  10. Bioassay technique for Plutella xylostella: Leaf-dip method%小菜蛾抗药性监测方法——叶片药膜法

    Institute of Scientific and Technical Information of China (English)

    郭磊; 边全乐; 张宏军; 高希武; 梁沛

    2013-01-01

    The diamondback moth, Plutella xylostella ( L. ) , is a notorious pest insect of cruciferous vegetables. Bioassays are an important technique for insecticide resistance monitoring and for screening the effectiveness of insecticides. This paper describes in detail the extensively used leaf dipping method in the DBM bioassay so as to provide a standard bioassay method for DBM and other lepidopterous pest insects.%小菜蛾Plutella xylostella(L.)是重要的十字花科蔬菜害虫.生物测定是进行害虫抗药性监测及筛选有效防治药剂的重要技术.本文对小菜蛾的生物测定技术进行了详细总结,以期为小菜蛾等鳞翅目害虫幼虫生物测定方法的规范提供依据.

  11. Two Novel Bioassays to Assess the Effects of Pyrethroid-Treated Netting on Knockdown-Susceptible Versus Resistant Strains of Aedes aegypti.

    Science.gov (United States)

    Denham, Steven; Eisen, Lars; Beaty, Meaghan; Beaty, Barry J; Black, William C; Saavedra-Rodriguez, Karla

    2015-03-01

    We describe 2 new mosquito bioassays for use with insecticide-treated netting or other textiles. The 1st is a cylinder bioassay in which a mosquito is forced to contact treated material regardless of where it lands within the bioassay construct. The 2nd is a repellency/irritancy and biting-inhibition bioassay (RIBB) in which human arms and breath are used as attractants. Mosquitoes have the choice to pass through holes cut in untreated or treated netting to move from a center release chamber into side chambers to reach arms and potentially bite. Trials were conducted with pyrethroid-susceptible (New Orleans), moderately resistant (Hunucmá), and highly resistant (Vergel) strains of Aedes aegypti. Tests with netting treated with different pyrethroids demonstrated the utility of the cylinder bioassay to quantify knockdown and mortality following exposure to treated netting, and of the RIBB to quantify spatial repellency/contact irritancy of the treated netting and biting inhibition after females land on and then pass through holes in the treated netting. Both tested brands of pyrethroid-treated mosquitocidal netting (DuraNet® and NetProtect®) were effective against New Orleans but ineffective against Vergel strains. Mortality in the cylinder bioassay was 100% for New Orleans for all tested brands of treated netting, but only 10-14% for Vergel. Rates of passage through treated netting to reach a human arm in the RIBB were 10-15% for New Orleans versus 24-37% for Vergel. The reduction in biting after passage through treated netting, compared with untreated netting in the same trial replicates, was 12-39% for New Orleans versus ≤9% for Vergel.

  12. Planetary Bioresources and Astroecology. 1. Planetary Microcosm Bioassays of Martian and Carbonaceous Chondrite Materials: Nutrients, Electrolyte Solutions, and Algal and Plant Responses

    Science.gov (United States)

    Mautner, Michael N.

    2002-07-01

    The biological fertilities of planetary materials can be assessed using microcosms based on meteorites. This study applies microcosm tests to martian meteorites and analogues and to carbonaceous chondrites. The biological fertilities of these materials are rated based on the soluble electrolyte nutrients, the growth of mesophile and cold-tolerant algae, and plant tissue cultures. The results show that the meteorites, in particular the Murchison CM2 carbonaceous chondrite and DaG 476 martian shergottite, contain high levels of water-extractable Ca, Mg, and SO 4-S. The martian meteorites DaG 476 and EETA 79001 also contain higher levels of extractable essential nutrients NO 3-N (0.013-0.017 g kg -1) and PO 4-P (0.019-0.046 g kg -1) than the terrestrial analogues. The yields of most of the water-extractable electrolytes vary only by factors of 2-3 under a wide range of planetary conditions. However, the long-term extractable phosphate increases significantly under a CO 2 atmosphere. The biological yields of algae and plant tissue cultures correlate with extractable NO 3-N and PO 4-P, identifying these as the limiting nutrients. Mesophilic algae and Asparagus officinalis cultures are identified as useful bioassay agents. A fertility rating system based on microcosm tests is proposed. The results rate the fertilities in the order martian basalts > terrestrial basalt, agricultural soil > carbonaceous chondrites, lava ash > cumulate igneous rock. The results demonstrate the application of planetary microcosms in experimental astroecology to rate planetary materials as targets for astrobiology exploration and as potential space bioresources. For example, the extractable materials in Murchison suggest that concentrated internal solutions in carbonaceous asteroids (3.8 mol L -1 electrolytes and 10 g L -1 organics) can support and disperse microorganisms introduced by natural or directed panspermia in early solar systems. The results also suggest that carbonaceous asteroids

  13. PET/CT Imaging of c-Myc Transgenic Mice Identifies the Genotoxic N-Nitroso-Diethylamine as Carcinogen in a Short-Term Cancer Bioassay

    OpenAIRE

    Katja Hueper; Mahmoud Elalfy; Florian Laenger; Roman Halter; Thomas Rodt; Michael Galanski; Juergen Borlak

    2012-01-01

    BACKGROUND: More than 100,000 chemicals are in use but have not been tested for their safety. To overcome limitations in the cancer bioassay several alternative testing strategies are explored. The inability to monitor non-invasively onset and progression of disease limits, however, the value of current testing strategies. Here, we report the application of in vivo imaging to a c-Myc transgenic mouse model of liver cancer for the development of a short-term cancer bioassay. METHODOLOGY/PRINCI...

  14. Multilaboratory evaluation of 15 bioassays for (eco)toxicity screening and hazard ranking of engineered nanomaterials: FP7 project NANOVALID.

    Science.gov (United States)

    Bondarenko, Olesja M; Heinlaan, Margit; Sihtmäe, Mariliis; Ivask, Angela; Kurvet, Imbi; Joonas, Elise; Jemec, Anita; Mannerström, Marika; Heinonen, Tuula; Rekulapelly, Rohit; Singh, Shashi; Zou, Jing; Pyykkö, Ilmari; Drobne, Damjana; Kahru, Anne

    2016-11-01

    Within EU FP7 project NANOVALID, the (eco)toxicity of 7 well-characterized engineered nanomaterials (NMs) was evaluated by 15 bioassays in 4 laboratories. The highest tested nominal concentration of NMs was 100 mg/l. The panel of the bioassays yielded the following toxicity order: Ag > ZnO > CuO > TiO2 > MWCNTs > SiO2 > Au. Ag, ZnO and CuO proved very toxic in the majority of assays, assumingly due to dissolution. The latter was supported by the parallel analysis of the toxicity of respective soluble metal salts. The most sensitive tests/species were Daphnia magna (towards Ag NMs, 24-h EC50 = 0.003 mg Ag/l), algae Raphidocelis subcapitata (ZnO and CuO, 72-h EC50 = 0.14 mg Zn/l and 0.7 mg Cu/l, respectively) and murine fibroblasts BALB/3T3 (CuO, 48-h EC50 = 0.7 mg Cu/l). MWCNTs showed toxicity only towards rat alveolar macrophages (EC50 = 15.3 mg/l) assumingly due to high aspect ratio and TiO2 towards R. subcapitata (EC50 = 6.8 mg Ti/l) due to agglomeration of TiO2 and entrapment of algal cells. Finally, we constructed a decision tree to select the bioassays for hazard ranking of NMs. For NM testing, we recommend a multitrophic suite of 4 in vitro (eco)toxicity assays: 48-h D. magna immobilization (OECD202), 72-h R. subcapitata growth inhibition (OECD201), 30-min Vibrio fischeri bioluminescence inhibition (ISO2010) and 48-h murine fibroblast BALB/3T3 neutral red uptake in vitro (OECD129) representing crustaceans, algae, bacteria and mammalian cells, respectively. Notably, our results showed that these assays, standardized for toxicity evaluation of "regular" chemicals, proved efficient also for shortlisting of hazardous NMs. Additional assays are recommended for immunotoxicity evaluation of high aspect ratio NMs (such as MWCNTs). PMID:27259032

  15. Confirmatory sediment analyses and solid and suspended particulate phase bioassays on sediment from Oakland Inner Harbor, San Francisco, California

    Energy Technology Data Exchange (ETDEWEB)

    Word, J.Q.; Ward, J.A.; Apts, C.W.; Woodruff, D.L.; Barrows, M.E.; Cullinan, V.I.; Hyland, J.L.; Campbell, J.F.

    1988-12-01

    The US Army Corps of Engineers (USACE), San Francisco District, was authorized by the US Congress to deepen the navigation channels of Inner and Outer Oakland Harbor, California. During review of the environmental impact statement required for this dredging and disposal project, a panel of national experts approved the open-water disposal of dredged sediment from selected areas within the Inner Harbor, subject to results of confirmatory solid phase bioassays. The San Francisco District of the Corps requested the Battle/Marine Sciences Laboratory (MSL) to conduct these confirmatory studies. The studies provided technical data for an evaluation of the potential environmental impact of this project. Within extremely narrow time constraints, these studies provided chemical and biological information required by ocean dumping regulations to determine suitability of the Oakland Inner Harbor and turning basin sediment for ocean disposal. 23 refs., 18 figs., 45 tabs.

  16. Phytotoxicity and Cytotoxicity of Essential Oil from Leaves of Plectranthus amboinicus, Carvacrol, and Thymol in Plant Bioassays.

    Science.gov (United States)

    Pinheiro, Patrícia Fontes; Costa, Adilson Vidal; Alves, Thammyres de Assis; Galter, Iasmini Nicoli; Pinheiro, Carlos Alexandre; Pereira, Alexandre Fontes; Oliveira, Carlos Magno Ramos; Fontes, Milene Miranda Praça

    2015-10-21

    The essential oil of Plectranthus amboinicus and its chemotypes, carvacrol and thymol, were evaluated on the germination and root and aerial growth of Lactuca sativa and Sorghum bicolor and in acting on the cell cycle of meristematic root cells of L. sativa. The main component found in the oil by analysis in gas chromatography-mass spectrometry and gas chromatography flame ionization detection was carvacrol (88.61% in area). At a concentration of 0.120% (w v(-1)), the oil and its chemotypes retarded or inhibited the germination and decreased root and aerial growth in monocot and dicot species used in the bioassays. In addition, all substances caused changes in the cell cycle of the meristematic cells of L. sativa, with chromosomal alterations occurring from the 0.015% (w v(-1)) concentration. The essential oil of P. amboinicus, carvacrol, and thymol have potential for use as bioherbicides. PMID:26416575

  17. Glucocorticoid activity detected by in vivo zebrafish assay and in vitro glucocorticoid receptor bioassay at environmental relevant concentrations.

    Science.gov (United States)

    Chen, Qiyu; Jia, Ai; Snyder, Shane A; Gong, Zhiyuan; Lam, Siew Hong

    2016-02-01

    Glucocorticoids are pharmaceutical contaminants of emerging concern due to their incomplete removal during wastewater treatment, increased presence in aquatic environment and their biological potency. The zebrafish is a popular model for aquatic toxicology and environmental risk assessment. This study aimed to determine if glucocorticoids at environmental concentrations would perturb expression of selected glucocorticoid-responsive genes in zebrafish and to investigate their potentials as an in vivo zebrafish assay in complementing in vitro glucocorticoid receptor bioassay. The relative expression of eleven glucocorticoid-responsive genes in zebrafish larvae and liver of adult male zebrafish exposed to three representative glucocorticoids (dexamethasone, prednisolone and triamcinolone) was determined. The expression of pepck, baiap2 and pxr was up-regulated in zebrafish larvae and the expression of baiap2, pxr and mmp-2 was up-regulated in adult zebrafish exposed to glucocorticoids at concentrations equivalent to total glucocorticoids reported in environmental samples. The responsiveness of the specific genes were sufficiently robust in zebrafish larvae exposed to a complex environmental sample detected with in vitro glucocorticoid activity equivalent to 478 pM dexamethasone (DEX-EQ) and confirmed to contain low concentration (0.2 ng/L or less) of the targeted glucocorticoids, and possibly other glucocorticoid-active compounds. The findings provided in vivo relevance to the in vitro glucocorticoid activity and suggested that the environmental sample can perturb glucocorticoid-responsive genes in its original, or half the diluted, concentration as may be found in the environment. The study demonstrated the important complementary roles of in vivo zebrafish and in vitro bioassays coupled with analytical chemistry in monitoring environmental glucocorticoid contaminants.

  18. Toxicity of sediment-bound pollutants in the Seine estuary, France, using a Eurytemora affinis larval bioassay.

    Science.gov (United States)

    Lesueur, Teddy; Boulangé-Lecomte, Céline; Restoux, Gwendal; Deloffre, Julien; Xuereb, Benoît; Le Menach, Karyn; Budzinski, Hélène; Petrucciani, Nathalie; Marie, Sabine; Petit, Fabienne; Forget-Leray, Joëlle

    2015-03-01

    Coastal urbanisation exposes surrounding estuarine environments to urban-related contaminants such as polycyclic aromatic hydrocarbons (PAHs), polychlorobiphenyls (PCBs) and pesticide mixtures. Hydrophobic contaminants can adsorb on estuarine sediments. They can subsequently be released on a massive scale in the aquatic environment due to artificial or natural phenomena (e.g. dredging, tides), thereby threatening living organisms. The contamination of sediment is a significant ecological issue in the Seine estuary, France. However, few relevant methods have been developed to assess sediment toxicity and its ecological impacts in a cost-effective way. In this context, we aimed to assess the toxicity of natural sediments from the Seine estuary on the development of the calanoid copepod Eurytemora affinis using a previously developed larval bioassay. This assay involves direct exposure of nauplii to elutriates of sediments for six days. Sediments were collected along the Seine estuary from six polluted sites and one reference site. Pollutants in this estuary included PAHs, PCBs and OCPs (organochlorine pesticides). Nauplius survival was significantly more affected by exposure to all contaminated sediment elutriates, than by exposure to sediment from Yville-sur-Seine (the reference site), whereas nauplius growth was significantly reduced after exposure to contaminated sediment elutriates from four of the six contaminated sites. We identified two distinct site clusters, one including both the sand-rich and the least polluted sediments (Oissel, Quillebeuf-sur-Seine, Caudebec-en-Caux) and the other including both the clay- and silt-rich, and the most polluted sediments (La Bouille, Poses, Pont de Normandie). As expected, survival was significantly more impacted after exposure to elutriates from the second cluster than from the first. This work enables (i) assessment of the toxicity of natural sediments in the Seine estuary and (ii) validation of the larval bioassay

  19. Dosimetry of Acrylamide and Glycidamide Over the Lifespan in a 2-Year Bioassay of Acrylamide in Wistar Han Rats.

    Science.gov (United States)

    Fennell, Timothy R; Snyder, Rodney; Hansen, Benjamin; Friedman, Marvin

    2015-08-01

    Acrylamide is an industrial chemical used to manufacture polymers, and is produced in foods during cooking at high heat. Hemoglobin adducts provide a long-lived dosimeter for acrylamide and glycidamide. This study determined acrylamide and glycidamide hemoglobin adducts (AAVal and GAVal) during a lifetime carcinogenesis bioassay. Exposure to acrylamide in drinking water began in utero in pregnant rats on gestation day 6. Dams were administered acrylamide until weaning, and male and female F1 rats were exposed for a further 104 weeks. Acrylamide concentration in drinking water was adjusted to provide a constant dose of 0.5, 1.5, and 3 mg/kg/day. Blood was collected from animals euthanized at 2, 60, 90, and 120 days and 53, 79, and 104 weeks after weaning. Low levels of AAVal and GAVal at postnatal day 24 suggested that little exposure to acrylamide occurred by placental or lactational transfer, and extensive metabolism to glycidamide occurred with a GAVal:AAVal ratio of 4. Adduct levels varied somewhat from 60 days to 2 years, with a GAVal:AAVal ratio of approximately 1. Adduct formation/day estimated at each timepoint at 3 mg/kg/day for AAVal was 1293 ± 220 and 1096 ± 338 fmol/mg/day for male and female rats, respectively. Adduct formation per day estimated at each timepoint at 3 mg/kg/day for GAVal was 827 ± 78 fmol/mg/day for male rats, and 982 ± 222 fmol/mg/day for female rats. The study has provided estimates of linearity for dose response, and variability in internal dose throughout an entire 2-year bioassay, including the early phases of pregnancy and lactation.

  20. WE-E-BRE-03: Biological Validation of a Novel High-Throughput Irradiator for Predictive Radiation Sensitivity Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, TL; Martin, JA; Shepard, AJ; Bailey, AM; Nickel, KP; Kimple, RJ; Bednarz, BP [University of Wisconsin, Madison, WI (United States)

    2014-06-15

    Purpose: The large dose-response variation in both tumor and normal cells between individual patients has led to the recent implementation of predictive bioassays of patient-specific radiation sensitivity in order to personalize radiation therapy. This exciting new clinical paradigm has led us to develop a novel high-throughput, variable dose-rate irradiator to accompany these efforts. Here we present the biological validation of this irradiator through the use of human cells as a relative dosimeter assessed by two metrics, DNA double-strand break repair pathway modulation and intercellular reactive oxygen species production. Methods: Immortalized human tonsilar epithelial cells were cultured in 96-well micro titer plates and irradiated in groups of eight wells to absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy. High-throughput immunofluorescent microscopy was used to detect γH2AX, a DNA double-strand break repair mechanism recruiter. The same analysis was performed with the cells stained with CM-H2DCFDA that produces a fluorescent adduct when exposed to reactive oxygen species during the irradiation cycle. Results: Irradiations of the immortalized human tonsilar epithelial cells at absorbed doses of 0, 0.5, 1, 2, 4, and 8 Gy produced excellent linearity in γH2AX and CM-H2DCFDA with R2 values of 0.9939 and 0.9595 respectively. Single cell gel electrophoresis experimentation for the detection of physical DNA double-strand breaks in ongoing. Conclusions: This work indicates significant potential for our high-throughput variable dose rate irradiator for patient-specific predictive radiation sensitivity bioassays. This irradiator provides a powerful tool by increasing the efficiency and number of assay techniques available to help personalize radiation therapy.

  1. Rapid yeast estrogen bioassays stably expressing human estrogen receptors alpha and beta, and green fluorescent protein: a comparison of different compounds on both receptor types

    NARCIS (Netherlands)

    Bovee, T.F.H.; Helsdingen, J.R.; Rietjens, I.M.C.M.; Keijer, J.; Hoogenboom, L.A.P.

    2004-01-01

    Previously, we described the construction of a rapid yeast bioassay stably expressing human estrogen receptor (hER) and yeast enhanced green fluorescent protein (yEGFP) in response to estrogens. In the present study, the properties of this assay were further studied by testing a series of estrogenic

  2. WILL THE MOUSE BIOASSAY FOR ESTIMATING SENSORY IRRITANCY OF AIRBORNE CHEMICALS (ASTM E 981-84) BE USEFUL FOR EVALUATION OF INDOOR AIR CONTAMINANTS

    Science.gov (United States)

    For many toxic inhalants, sensory irritation is the first detectable response. tandardized bioassay, ASTM E 981-84, that quantitates irritancy as a reduction in breathing rate of the mouse during inhalation exposure, has been developed. he validation of this screen for detecting ...

  3. Assessment of the genotoxicity of 137Cs radiation using Vicia-micronucleus, Tradescantia-micronucleus and Tradescantia-stamen-hair mutation bioassays.

    Science.gov (United States)

    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.

  4. Predicting Field Control of Tarnished Plant Bug (Heteroptera: Miridae) Populations with Pyrethroid Insecticides by Use of Two Glass-Vial Bioassays

    Science.gov (United States)

    Tarnished plant bug, Lygus lineolaris (Palisot de beauvois), populations from 21 locations in the Mississippi River Delta of Arkansas and Mississippi were tested for resistance to permethrin in 2004 and 2005. Each population was tested using permethrin in a discriminating-dose bioassay to determine...

  5. Remote video bioassays reveal the potential feeding impact of the rabbitfish Siganus canaliculatus (f: Siganidae) on an inner-shelf reef of the Great Barrier Reef

    Science.gov (United States)

    Fox, R. J.; Bellwood, D. R.

    2008-09-01

    Herbivores are widely acknowledged as key elements maintaining the health and resilience of terrestrial and aquatic ecosystems. Understanding and quantifying the impact of herbivores in ecosystems are fundamental to our ability to manage these systems. The traditional method of quantifying the impact of herbivorous fishes on coral reefs has been to use transplanted pieces of seagrass or algae as “bioassays”. However, these experiments leave a key question unanswered, namely: Which species are responsible for the impact being quantified? This study revisits the use of bioassays and tested the assumption that the visual abundance of species reflects their role in the removal of assay material. Using remote video cameras to film removal of assay material on an inner-shelf reef of the Great Barrier Reef, the species responsible for assay-based herbivory were identified. The video footage revealed that Siganus canaliculatus, a species not previously recorded at the study site, was primarily responsible for removal of macroalgal biomass. The average percentage decrease in thallus length of whole plants of Sargassum at the reef crest was 54 ± 8.9% (mean ± SE), and 50.4 ± 9.8% for individually presented Sargassum strands (for a 4.5-h deployment). Of the 14,656 bites taken from Sargassum plants and strands across all reef zones, nearly half (6,784 bites or 46%) were taken by S. canaliculatus, with the majority of the remainder attributable to Siganus doliatus. However, multiple regression analysis demonstrated that only the bites of S. canaliculatus were removing macroalgal biomass. The results indicate that, even with detailed observations, the species of herbivore that may be responsible for maintaining benthic community structure can go unnoticed. Some of our fundamental ideas of the relative importance of individual species in ecosystem processes may be in need of re-evaluation.

  6. PAH-CALUX, an optimized bioassay for AhR-mediated hazard identification of polycyclic aromatic hydrocarbons (PAHs) as individual compounds and in complex mixtures.

    Science.gov (United States)

    Pieterse, B; Felzel, E; Winter, R; van der Burg, B; Brouwer, A

    2013-10-15

    Polycyclic aromatic hydrocarbons (PAHs) represent a class of ubiquitously occurring environmental compounds that are implicated in a wide range of toxicological effects. Routine measurement of PAH contamination generally involves chemical analytical analysis of a selected group of representatives, for example, EPA-16, which may result in underestimation of the PAH-related toxicity of a sample. Many high molecular weight PAHs are known ligands of the aryl hydrocarbon receptor (AhR), a nuclear receptor that mediates toxic effects related to these compounds. Making use of this property we developed a PAH CALUX assay, a mammalian, H4IIe- cell-based reporter assay for the hazard identification of total PAH mixtures. The PAH CALUX reporter cell line allows for specific, rapid (4 h exposure time) and reliable quantification of AhR-induced luciferase induction relative to benzo[a]pyrene (BaP), which is used as a positive reference PAH congener. Full dose response relationships with inductions over 100-fold were reached within only 2 h of exposure to BaP. The PAH CALUX is highly sensitive, that is, using a 4 h exposure time, a limit of detection (LOD) of 5.2 × 10(-11) M BaP was achieved, and highly accurate, that is, a repeatability of 5.9% and a reproducibility of 6.6% were established. Screening of a selection of PAHs that were prioritized by the European Union and/or the U.S. Environmental Protection Agency showed that the PAH CALUX bioassay has a high predictability, particularly for carcinogenic PAHs. Experiments with synthetic mixtures and reference materials containing complex PAH mixtures show the suitability of the assay for these types of applications. Moreover, the presented results suggest that application of the PAH CALUX will result in a lower risk of underestimation of the toxicity of a sample than chemical analytical approaches that focus on a limited set of prioritized compounds.

  7. Design Strategies for Aptamer-Based Biosensors

    Directory of Open Access Journals (Sweden)

    Kun Han

    2010-05-01

    Full Text Available Aptamers have been widely used as recognition elements for biosensor construction, especially in the detection of proteins or small molecule targets, and regarded as promising alternatives for antibodies in bioassay areas. In this review, we present an overview of reported design strategies for the fabrication of biosensors and classify them into four basic modes: target-induced structure switching mode, sandwich or sandwich-like mode, target-induced dissociation/displacement mode and competitive replacement mode. In view of the unprecedented advantages brought about by aptamers and smart design strategies, aptamer-based biosensors are expected to be one of the most promising devices in bioassay related applications.

  8. Surface-Enhanced Raman Spectroscopy Based Quantitative Bioassay on Aptamer-Functionalized Nanopillars Using Large-Area Raman Mapping

    DEFF Research Database (Denmark)

    Yang, Jaeyoung; Palla, Mirko; Bosco, Filippo;

    2013-01-01

    functionalized with aptamers for sensitive and specific detection of target molecules. In this study, TAMRA-labeled vasopressin molecules in the picomolar regime (1 pM to 1 nM) are specifically captured by aptamers on the nanostructured SERS substrate and monitored by using an automated SERS signal mapping...... reliable analysis of each measurement. Combining our SERS mapping analysis with an aptamer-functionalized nanopillar substrate is found to be extremely efficient for detection of low-abundance biomolecules....

  9. Fluidic automation of nitrate and nitrite bioassays in whole blood by dissolvable-film based centrifugo-pneumatic actuation

    DEFF Research Database (Denmark)

    Nwankire, Charles E.; Chan, Di-Sien S.; Gaughran, Jennifer;

    2013-01-01

    by the radial position, geometry and volume of the valve chamber and its inlet channel and can thus be individually tuned over an extraordinarily wide range of equivalent spin rates between 1,000 RPM and 5,500 RPM. Furthermore, the vapour barrier properties of the DF valves are investigated in this paper...

  10. Fluidic Automation of Nitrate and Nitrite Bioassays in Whole Blood by Dissolvable-Film Based Centrifugo-Pneumatic Actuation

    Directory of Open Access Journals (Sweden)

    Jens Ducrée

    2013-08-01

    Full Text Available This paper demonstrates the full centrifugal microfluidic integration and automation of all liquid handling steps of a 7-step fluorescence-linked immunosorbent assay (FLISA for quantifying nitrate and nitrite levels in whole blood within about 15 min. The assay protocol encompasses the extraction of metered plasma, the controlled release of sample and reagents (enzymes, co-factors and fluorescent labels, and incubation and detection steps. Flow control is implemented by a rotationally actuated dissolvable film (DF valving scheme. In the valves, the burst pressure is primarily determined by the radial position, geometry and volume of the valve chamber and its inlet channel and can thus be individually tuned over an extraordinarily wide range of equivalent spin rates between 1,000 RPM and 5,500 RPM. Furthermore, the vapour barrier properties of the DF valves are investigated in this paper in order to further show the potential for commercially relevant on-board storage of liquid reagents during shelf-life of bioanalytical, ready-to-use discs.

  11. A mobile bioassay laboratory for the assessment of internal doses based on in vivo and in vitro measurements

    International Nuclear Information System (INIS)

    Accidental internal exposure may occur in practices such as nuclear power reactor operation, production of radioisotopes and use of unsealed radioactive sources in medicine and research. Such practices require an infrastructure for quick response in the case of nuclear and radiological accidents of a wide range of magnitudes. The goal of this work is to design and calibrate a mobile laboratory for the mitigation of accidents involving workers and population exposure as well as for routine monitoring of internal contamination. The detectors available in the mobile laboratory can identify and quantify photon emitters in the energy range of 100-3000 keV in the whole body, organs or tissues and in urine samples. The system was set up in a truck with internal dimensions of 3.30m x 1.60m x 1.70m. A thyroid monitor consisting of a lead-collimated NaI(Tl)3x3 was calibrated with a neck-thyroid phantom developed at the IRD. Whole body measurements are performed with a NaI(Tl)8x4 calibrated with a plastic-bottle phantom containing standard solutions uniformly distributed among its various sections. Urine samples are measured with a second NaI(Tl) 3x3 detector set up in a steel support. Standard radionuclide solutions were prepared and certified by the National Laboratory for Metrology of Ionizing Radiation (LNMRI) located at the IRD. In vitro measurements of urine samples use a calibration curve of efficiency versus energy for standard volumes. In vivo and In vitro detection limits were converted to committed doses for the radionuclides of interest using current biokinetic and dosimetric models to evaluate the applicability and limitations of the system. Dose detection limits obtained for the activation and fission products of high energy show that the system sensitivity is suitable for use in emergency situations as well as in routine monitoring of workers subject to risk of internal exposure by such radionuclides. (author)

  12. 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

    Energy Technology Data Exchange (ETDEWEB)

    Lipsky, S.R.; Alexander, G.; McMurray, W.; Capizzi, R.

    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 particular bioassay system.

  13. Determination of bacteriocin activity with bioassays carried out on solid and liquid substrates: assessing the factor "indicator microorganism"

    Directory of Open Access Journals (Sweden)

    Ambrosiadis Ioannis

    2006-10-01

    Full Text Available Abstract Background Successful application of growth inhibition techniques for quantitative determination of bacteriocins relies on the sensitivity of the applied indicator microorganism to the bacteriocin to which is exposed. However, information on indicator microorganisms' performance and comparisons in bacteriocin determination with bioassays is almost non-existing in the literature. The aim of the present work was to evaluate the parameter "indicator microorganism" in bioassays carried out on solid -agar diffusion assay- and liquid -turbidometric assay- substrates, applied in the quantification of the most studied bacteriocin nisin. Results The performance of characterized microorganisms of known sources, belonging to the genera of Lactobacillus, Pediococcus, Micrococcus and Leuconostoc, has been assessed in this work in the assays of plate agar diffusion and turbidometry. Dose responses and sensitivities were examined and compared over a range of assay variables in standard bacteriocin solutions, fermentation broth filtrates and processed food samples. Measurements on inhibition zones produced on agar plates were made by means of digital image analysis. The data produced were analyzed statistically using the ANOVA technique and pairwise comparisons tests. Sensitivity limits and linearity of responses to bacteriocin varied significantly among different test-microorganisms in both applied methods, the lower sensitivity limits depending on both the test-microorganism and the applied method. In both methods, however, only two of the nine tested microorganisms (Lactobacillus curvatus ATCC 51436 and Pediococcus acidilactici ATCC 25740 were sensitive to very low concentrations of the bacteriocin and produced a linear-type of response in all kinds of samples used in this work. In all cases, very low bacteriocin concentrations, e.g. 1 IU/ml nisin, were more accurately determined in the turbidometric assay. Conclusion The present work shows that in

  14. Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction

    International Nuclear Information System (INIS)

    Research highlights: → We identified four sequence motifs lying upstream of putative pro-longevity genes. → One of these motifs binds to HNF-4α. → HNF-4α/PGC-1α could up-regulate the transcription of a reporter gene linked to this motif. → The reporter system described here could be used to screen candidate anti-aging molecules. -- Abstract: Suppression of the growth hormone/insulin-like growth factor-I pathway in Ames dwarf (DF) mice, and caloric restriction (CR) in normal mice extends lifespan and delays the onset of age-related disorders. In combination, these interventions have an additive effect on lifespan in Ames DF mice. Therefore, common signaling pathways regulated by DF and CR could have additive effects on longevity. In this study, we tried to identity the signaling mechanism and develop a system to assess pro-longevity status in cells and mice. We previously identified genes up-regulated in the liver of DF and CR mice by DNA microarray analysis. Motif analysis of the upstream sequences of those genes revealed four major consensus sequence motifs, which have been named dwarfism and calorie restriction-responsive elements (DFCR-REs). One of the synthesized sequences bound to hepatocyte nuclear factor-4α (HNF-4α), an important transcription factor involved in liver metabolism. Furthermore, using this sequence information, we developed a highly sensitive bioassay to identify chemicals mimicking the anti-aging effects of CR. When the reporter construct, containing an element upstream of a secreted alkaline phosphatase (SEAP) gene, was co-transfected with HNF-4α and its regulator peroxisome proliferator-activated receptor (PPAR) γ coactivator-1α (PGC-1α), SEAP activity was increased compared with untransfected controls. Moreover, transient transgenic mice established using this construct showed increased SEAP activity in CR mice compared with ad libitum-fed mice. These data suggest that because of its rapidity, ease of use, and specificity

  15. Development of a bioassay to screen for chemicals mimicking the anti-aging effects of calorie restriction

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Takuya, E-mail: takuya@nagasaki-u.ac.jp [Department of Investigative Pathology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Tsuchiya, Tomoshi [Division of Surgical Oncology, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8501 (Japan); Komatsu, Toshimitsu; Mori, Ryoichi; Hayashi, Hiroko [Department of Investigative Pathology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan); Shimano, Hitoshi [Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba Ibaraki 305-8575 (Japan); Spindler, Stephen R. [Department of Biochemistry, Room 5478, Boyce Hall, University of California - Riverside, Riverside, CA 92521 (United States); Shimokawa, Isao [Department of Investigative Pathology, Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523 (Japan)

    2010-10-15

    Research highlights: {yields} We identified four sequence motifs lying upstream of putative pro-longevity genes. {yields} One of these motifs binds to HNF-4{alpha}. {yields} HNF-4{alpha}/PGC-1{alpha} could up-regulate the transcription of a reporter gene linked to this motif. {yields} The reporter system described here could be used to screen candidate anti-aging molecules. -- Abstract: Suppression of the growth hormone/insulin-like growth factor-I pathway in Ames dwarf (DF) mice, and caloric restriction (CR) in normal mice extends lifespan and delays the onset of age-related disorders. In combination, these interventions have an additive effect on lifespan in Ames DF mice. Therefore, common signaling pathways regulated by DF and CR could have additive effects on longevity. In this study, we tried to identity the signaling mechanism and develop a system to assess pro-longevity status in cells and mice. We previously identified genes up-regulated in the liver of DF and CR mice by DNA microarray analysis. Motif analysis of the upstream sequences of those genes revealed four major consensus sequence motifs, which have been named dwarfism and calorie restriction-responsive elements (DFCR-REs). One of the synthesized sequences bound to hepatocyte nuclear factor-4{alpha} (HNF-4{alpha}), an important transcription factor involved in liver metabolism. Furthermore, using this sequence information, we developed a highly sensitive bioassay to identify chemicals mimicking the anti-aging effects of CR. When the reporter construct, containing an element upstream of a secreted alkaline phosphatase (SEAP) gene, was co-transfected with HNF-4{alpha} and its regulator peroxisome proliferator-activated receptor (PPAR) {gamma} coactivator-1{alpha} (PGC-1{alpha}), SEAP activity was increased compared with untransfected controls. Moreover, transient transgenic mice established using this construct showed increased SEAP activity in CR mice compared with ad libitum-fed mice. These data

  16. Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in 85Rb

    Institute of Scientific and Technical Information of China (English)

    LIU Lu; GUO Tao; DENG Ke; LIU Xin-Yuan; CHEN Xu-Zong; WANG Zhong

    2007-01-01

    An atomic clock system based on coherent population trapping (CPT) resonance in 85Rb is reported, while most past works about the CPT clock are in 87Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in 85Rb. The experimental results show that the short-term frequency stability of the CPT clock in 85Rb is in the order of 10-10/s and the long-term frequency stability can achieve 1.5 × 10-11 /80000s, which performs as well as 87Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of 85Rb indicates that an atomic clock based on CPT in 85 Rb should be a promising candidate for making the chip scale atomic clock.

  17. Lutetium speciation and toxicity in a microbial bioassay: Testing the free-ion model for lanthanides

    NARCIS (Netherlands)

    Weltje, L.; Verhoof, L.R.C.W.; Verweij, W.; Hamers, T.H.M.

    2004-01-01

    The validity of the free-ion model (FIM) for the element lutetium (Lu), a member of the lanthanides, was assessed in experiments with the bacterium Vibrio fischeri. The FIM is mainly based on divalent metals and synthetic ligands and has not yet been validated for the trivalent lanthanides. The biol

  18. Zebrafish (Danio rerio) bioassay for visceral toxicosis of catfish and botulinum neurotoxin serotype E

    Science.gov (United States)

    Visceral toxicosis of catfish (VTC), a sporadic disease of cultured channel catfish (Ictalurus punctatus) often with high mortality, is caused by botulinum neurotoxin serotype E (BoNT/E). Presumptive diagnosis of VTC is based on characteristic clinical signs and lesions, and the production of these ...

  19. Application of bioassays in toxicological hazard, risk and impact assessments of dredged sediments

    NARCIS (Netherlands)

    Schipper, C.A.; Rietjens, I.M.C.M.; Burgerss, R.M.; Murk, A.J.

    2010-01-01

    Given the potential environmental consequences of dumped dredged harbour sediments it is vital to establish the potential risks from exposure before disposal at sea. Currently, European legislation for disposal of contaminated sediments at sea is based on chemical analysis of a limited number of wel

  20. Bioassay-guided isolation of dehydrocostus lactone from Saussurea lappa: A new targeted cytosolic thioredoxin reductase anticancer agent.

    Science.gov (United States)

    Yang, Meili; Zhang, Junmin; Li, Ya; Han, Xiao; Gao, Kun; Fang, Jianguo

    2016-10-01

    In a screen for mammalian thioredoxin reductases inhibitors, an MeOH extract from the roots of Saussurea lappa C.B. Clarke (Compositae) inhibited the activity of cytosolic thioredoxin reductase (TrxR1). Bioassay-guided separation of the extract led to the isolation of a new TrxR1 inhibitor, dehydrocostus lactone (DHC), a guaiane-type sesquiterpene. The content of DHC in the extract was determined to be 0.4%. DHC inhibited human cervical carcinoma HeLa cells with an IC50 of ∼12.00 μM but displayed less cytotoxicity to human immortalized normal liver cells L02. We observed that DHC killed HeLa cells through induction of apoptosis. DHC inhibited the activity of TrxR1 in HeLa cells, which elicited an accumulation of reactive oxygen species (ROS) in cells and a collapse of the intracellular redox equilibrium and eventually induced apoptosis of HeLa cells. PMID:27545438

  1. Bioassay-Guided Isolation of Cytotoxic Cycloartane Triterpenoid Glycosides from the Traditionally Used Medicinal Plant Leea indica

    Directory of Open Access Journals (Sweden)

    Yau Hsiung Wong

    2012-01-01

    Full Text Available Leea indica is a medicinal plant used traditionally to cure cancer. In this study, the cytotoxic compounds of L. indica were isolated using bioassay-guided approach. Two cycloartane triterpenoid glycosides, mollic acid arabinoside (MAA and mollic acid xyloside (MAX, were firstly isolated from L. indica. They inhibited the growth of Ca Ski cervical cancer cells with IC50 of 19.21 μM (MAA and 33.33 μM (MAX. MRC5 normal cell line was used to calculate selectivity index. MAA and MAX were about 8 and 4 times more cytotoxic to Ca Ski cells compared to MRC5. The cytotoxicity of MAA was characterized by both cytostatic and cytocidal effects. MAA decreased the expression of proliferative cell nuclear antigen, increased sub-G1 cells, and arrested cells in S and G2/M phases. This study provides the evidence for the ethnomedicinal use of L. indica and paves the way for future mechanism studies on the anticancer effects of MAA.

  2. Ovarian 32P uptake in the homoplastic hypophysectomized catfish, Heteropneustes fossilis as an end point for gonadotropin bioassay

    International Nuclear Information System (INIS)

    Ovarian 32P incorporation in hypophysectomized Heteropneustes fossilis in response to pituitary gland extract pooled from same species and mammalian gonadotropic preparations were studied. Maximum 32P uptake by ovary was obtained when a tracer dose of radiophosphorus was given 30 minutes after LH injection and fish were sacrificed 12 hours after the tracer shot. A log-dose response was observed between ovarian 32P uptake and gonadotropic content of pituitary extract or LH in hypophysectomized H. fossilis. This response was specific because FSH, TSH, prolactin and growth hormone injections failed to induce dose dependent and significant 32P uptake by ovary in similar assay recipients. However, FSH along with LH at higher dosage yielded an additive response. Also a parallelism of log-dose response was obtained between fish pituitary gonadotropin and ovine LH. Index of precision (Λ) was less than 0.214. Since donors and recipients were of the same species this bioassay of 12.5 hours for estimation of total gonadotropic potency seems to be rapid, reliable, sensitive and free from phylogenetic species specificity interaction between hormone and its receptor. (author)

  3. Evaluation of the antiproliferative activity of the leaves from Arctium lappa by a bioassay-guided fractionation.

    Science.gov (United States)

    Machado, Fabio Bahls; Yamamoto, Rafael Eidi; Zanoli, Karine; Nocchi, Samara Requena; Novello, Cláudio Roberto; Schuquel, Ivânia Teresinha Albrecht; Sakuragui, Cássia Mônica; Luftmann, Heinrich; Ueda-Nakamura, Tânia; Nakamura, Celso Vataru; de Mello, João Carlos Palazzo

    2012-02-14

    Arctium lappa L. (Asteraceae) is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetate, and n-butanol. The ethyl-acetate fraction (EAF) showed antiproliferative activity. This fraction was subjected to sequential column chromatography over silica gel to afford onopordopicrin (1), mixtures of 1 with dehydromelitensin-8-(4'-hydroxymethacrylate) (2), a mixture of 2 with dehydromelitensin (3), mixture of 1 with melitensin (4), dehydrovomifoliol (5), and loliolide (6). The compounds were identified by spectroscopic methods (NMR, MS) and comparison with literature data. This is the first description of compounds 2-5 from this species. The compounds tested in Caco-2 cells showed the following CC(50) (µg/mL) values: 1: 19.7 ± 3.4, 1 with 2: 24.6 ± 1.5, 2 with 3: 27 ± 11.7, 1 with 4: 42 ± 13.1, 6 30 ± 6.2; compound 5 showed no activity.

  4. Evaluation of the Antiproliferative Activity of the Leaves from Arctium lappa by a Bioassay-Guided Fractionation

    Directory of Open Access Journals (Sweden)

    Celso Vataru Nakamura

    2012-02-01

    Full Text Available Arctium lappa L. (Asteraceae is used in folk medicine around the World, and shows several kinds of biological activity, particularly in vitro antitumor activity in different cell lines. This study evaluated the antiproliferative activity of the crude extract, semipurified fractions, and isolated compounds from the leaves of A. lappa, through bioassay-guided testing in Caco-2 cells. The crude extract was obtained with a 50% hydroethanolic extract and then partitioned with hexane, ethyl acetate, and n-butanol. The ethyl-acetate fraction (EAF showed antiproliferative activity. This fraction was subjected to sequential column chromatography over silica gel to afford onopordopicrin (1, mixtures of 1 with dehydromelitensin-8-(4'-hydroxymethacrylate (2, a mixture of 2 with dehydromelitensin (3, mixture of 1 with melitensin (4, dehydrovomifoliol (5, and loliolide (6. The compounds were identified by spectroscopic methods (NMR, MS and comparison with literature data. This is the first description of compounds 2–5 from this species. The compounds tested in Caco-2 cells showed the following CC50 (µg/mL values: 1: 19.7 ± 3.4, 1 with 2: 24.6 ± 1.5, 2 with 3: 27 ± 11.7, 1 with 4: 42 ± 13.1, 6 30 ± 6.2; compound 5 showed no activity.

  5. Bioassay-Guided Isolation of DPP-4 Inhibitory Fractions from Extracts of Submerged Cultured of Inonotus obliquus

    Directory of Open Access Journals (Sweden)

    Jin-Song Shi

    2013-01-01

    Full Text Available Inonotus obliquus is a medicinal mushroom used in Russian and Eastern European folk medicine for the treatment of gastrointestinal cancer, cardiovascular disease and diabetes. Previous studies in our laboratory have demonstrated that the mycelium powders of I. obliquus possess significant antihyperglycemic effects in a mouse model of diabetic disease induced by alloxan. However, the active ingredients of mycelium powders responsible for the diabetes activity have not been identified. This study aims to identify the active ingredients of I. obliquus mycelium powders by a bioassay-guided fractionation approach and explore the mechanism of action of these active ingredients by using a well-established DPP-4 (an important enzyme as a new therapeutic target for diabetes inhibitory assay model. The results showed the chloroform extract of mycelium was potential inhibitory against DPP-4. Bioactivity guided fractionation led to the identification of 19 compounds using UPLC-Q-TOF-MS. Molecular docking between the compounds and DPP-4 revealed that compounds 5, 8, 9, 14, 15 may be the active components responsible for the DPP-4 inhibitory activity.

  6. Bioassay-guided isolation of DPP-4 inhibitory fractions from extracts of submerged cultured of Inonotus obliquus.

    Science.gov (United States)

    Geng, Yan; Lu, Zhen-Ming; Huang, Wei; Xu, Hong-Yu; Shi, Jin-Song; Xu, Zheng-Hong

    2013-01-01

    Inonotus obliquus is a medicinal mushroom used in Russian and Eastern European folk medicine for the treatment of gastrointestinal cancer, cardiovascular disease and diabetes. Previous studies in our laboratory have demonstrated that the mycelium powders of I. obliquus possess significant antihyperglycemic effects in a mouse model of diabetic disease induced by alloxan. However, the active ingredients of mycelium powders responsible for the diabetes activity have not been identified. This study aims to identify the active ingredients of I. obliquus mycelium powders by a bioassay-guided fractionation approach and explore the mechanism of action of these active ingredients by using a well-established DPP-4 (an important enzyme as a new therapeutic target for diabetes) inhibitory assay model. The results showed the chloroform extract of mycelium was potential inhibitory against DPP-4. Bioactivity guided fractionation led to the identification of 19 compounds using UPLC-Q-TOF-MS. Molecular docking between the compounds and DPP-4 revealed that compounds 5, 8, 9, 14, 15 may be the active components responsible for the DPP-4 inhibitory activity. PMID:23325103

  7. Evaluation of Membrane Stabilizing Activity, Total Phenolic Content, Brine Shrimp Lethality Bioassay, Thrombolytic and Antimicrobial Activities of Tagetes patula L.

    Directory of Open Access Journals (Sweden)

    Md. Ruhul Kuddus

    2012-11-01

    Full Text Available The methanol extract of leaf of Tagetes patula L. as well as its n-hexane, carbon tetrachloride, chloroform and aqueous soluble partitionates were subjected to screening for total phenolic content, brine shrimp lethality, membrane stabilizing, thrombolytic and antimicrobial activity. The membrane stabilizing activity was assessed by hypotonic solution-and heat-induced methods and was compared with acetyl salicylic acid. In the present studies, the n-hexane soluble fraction demonstrated strong membrane stabilizing activity in both hypotonic solution-and heat-induced methods with 44.48% and 42.68% inhibition of haemolysis, respectively. The total phenolic content was also determined and expressed in gallic acid equivalent. In brine shrimp bioassay, the crude methanol extract of leaf showed strong cytotoxic activity with LC50 value of 8.58 μg/ml compared to that of 0.451 μg/ml exhibited by standard vincristine sulphate. During assay for thrombolytic activity, the n-hexane soluble fraction revealed 43.7% lysis of clot while standard streptokinase and water, used as positive and negative controls, demonstrated 65.8% and 3.62% lysis of clot, respectively. In antimicrobial assay by disc diffusion method, all the samples exhibited moderate to significant antimicrobial activity (zone of inhibition = 9.0-22.0 mm against all the test organisms. Among all the samples, the carbon tetrachloride soluble fraction displayed strong antimicrobial activity against Escherichia coli (22.0 mm.

  8. Re-evaluation of the kidney tumors and renal histopathology occurring in a 2-year rat carcinogenicity bioassay of quercetin.

    Science.gov (United States)

    Hard, Gordon C; Seely, John Curtis; Betz, Laura J; Hayashi, Shim-Mo

    2007-04-01

    Renal histopathology in the most recent 2-year carcinogenicity bioassay of quercetin, in Fischer 344 rats, was re-evaluated in an attempt to determine a mode of action underlying a small increase in renal tubule tumors reported in the males (). The re-evaluation confirmed the reported increase in renal tumors in mid- and high-dose males, including a single carcinoma in a high-dose male, as well as an exacerbation of spontaneous, chronic progressive nephropathy (CPN) in male rats only. The re-evaluation also showed that there were no cellular alterations in the kidney indicative of chemical toxicity at 6 months, 15 months, or 2 years. The evidence linked the occurrence of the predominant basophilic adenomas and foci of atypical tubule hyperplasia (ATH) with the exacerbation of CPN to advanced grades of severity, supporting a mode of action involving quercetin interaction with CPN. This mode of action represents a secondary mechanism for renal tumor development, with no relevance for extrapolation to humans. In addition, the single carcinoma present in the high-dose males, along with 4 other lesions ranging from ATH to adenoma in male and female groups, were considered to have a unique phenotype associated previously with neoplasms of spontaneous and familial origin.

  9. Determination of marine biotoxins relevant for regulations: from the mouse bioassay to coupled LC-MS methods.

    Science.gov (United States)

    Christian, Bernd; Luckas, Bernd

    2008-05-01

    The frequency of occurrence and intensity of harmful algal blooms (HABs) appear to be increasing on a global scale. Consequently, methods were established for the evaluation of possible hazards caused by the enrichment of algal toxins in the marine food chain. Different clinical types of algae-related poisoning have attracted scientific attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). In several countries fish specialties are consumed which may be contaminated with algal toxins typical for the respective region (e.g., ciguatera and tetrodotoxins). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, due to the low sensitivity and the absence of specialized variations. Moreover, there is growing resistance against the use of animal experiments. Therefore, many efforts have been made to determine algal toxins with chemical methods. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins.

  10. Inhibition of Oxidative Stress and Lipid Peroxidation by Anthocyanins from Defatted Canarium odontophyllum Pericarp and Peel Using In Vitro Bioassays

    Science.gov (United States)

    Khoo, Hock Eng; Azlan, Azrina; Ismail, Amin; Abas, Faridah; Hamid, Muhajir

    2014-01-01

    Canarium odontophyllum, also known as CO, is a highly nutritious fruit. Defatted parts of CO fruit are potent sources of nutraceutical. This study aimed to determine oxidative stress and lipid peroxidation effects of defatted CO pericarp and peel extracts using in vitro bioassays. Cell cytotoxic effect of the CO pericarp and peel extracts were also evaluated using HUVEC and Chang liver cell lines. The crude extracts of defatted CO peel and pericarp showed cytoprotective effects in t-BHP and 40% methanol-induced cell death. The crude extracts also showed no toxic effect to Chang liver cell line. Using CD36 ELISA, NAD+ and LDL inhibition assays, inhibition of oxidative stress were found higher in the crude extract of defatted CO peel compared to the pericarp extract. Hemoglobin and LDL oxidation assays revealed both crude extracts had significantly reduced lipid peroxidation as compared to control. TBARS values among defatted CO pericarp, peel, and cyanidin-3-glucoside showed no significant differences for hemoglobin and LDL oxidation assays. The protective effects of defatted CO parts, especially its peel is related to the presence of high anthocyanin that potentially offers as a pharmaceutical ingredient for cardioprotection. PMID:24416130

  11. BIOASSAY-GUIDED FRACTIONATION AND ANTIHYPERTENSIVE PROPERTIES OF FRACTIONS AND CRUDE EXTRACTS OF PERISTROPHE BICALYCULATA (RETZ) NEES.

    Science.gov (United States)

    Abdulazeez, Mansurah A; Ibrahim, Sani; Ameh, Danladi A; Ameh, Danladi Amodu; Ayo, Joseph O; Carvalho, Luiz J C B; Manosroi, Jiradej; Ibrahim, Abdulrazak B

    2015-01-01

    Hypertension is an important public health issue in both developed and developing countries due to its high incidence and morbidity. This has motivated researchers especially in developing countries to search for strategies for the treatment using different plant parts. The use of the aqueous decoction of the leaves of Peristiophe bicalyculata in the treatment of hypertension has been documented. This study was designed to carry out a bioassay-guided isolation of the antihypertensive components of the leaves of Peristrophe bicalyculata in L-NAME hypertensive rats, determine the angiotensin-converting enzyme inhibitory activity of the extracts and fractions obtained and identify the constituent(s) present. From our results, L-NAME hypertensive rats given the cold water extract had significantly (p present work demonstrates the hypotensive effect of the cold water extract of Peiistiophe bicalyculata on L-NAME hypertensive rats, which further justifies the folkloric application of extracts of the plant in the management as well as treatment of hypertension. PMID:26642682

  12. Anti-bacterial activity and brine shrimp lethality bioassay of methanolic extracts of fourteen different edible vegetables from Bangladesh

    Institute of Scientific and Technical Information of China (English)

    MObayedUllah; MahmudaHaque; KanizFatimaUrmi; AbuHasanatMdZulfiker; ElicheaSynthiAnita; MomtajBegum; KaiserHamid

    2013-01-01

    Objective: To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh. Methods: The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria (both gram positive and gram negative). The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations (LC50) were determined at 95% confidence intervals by analyzing the data on a computer loaded with “Finney Programme”. Results: All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains (zone of inhibition=5-28 mm). The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis (zone of inhibition=6-21 mm). All extracts exhibited considerable general toxicity towards brine shrimps. The LC50 value of the tested extracts was within the range of 8.447 to 60.323 µg/mL with respect to the positive control (vincristine sulphate) which was 0.91 µg/mL. Among all studied extracts, Xanthium indicum displayed the highest cytotoxic effect with LC50 value of 8.447 µg/mL. Conclusions: The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.

  13. Anti-bacterial activity and brine shrimp lethality bioassay of methanolic extracts of fourteen different edible vegetables from Bangladesh

    Institute of Scientific and Technical Information of China (English)

    M.Obayed; Ullah; Mahmuda; Haque; Kaniz; Fatima; Urmi; Abu; Hasanat; Md.Zulfiker; Elichea; Synthi; Anita; Momtaj; Begum; Kaiser; Hamid

    2013-01-01

    Objective:To investigate the antibacterial and cytotoxic activity of fourteen different edible vegetables methanolic extract from Bangladesh.Methods:The antibacterial activity was evaluated using disc diffusion assay method against 12 bacteria(both gram positive and gram negative).The plant extracts were also screened for cytotoxic activity using the brine shrimp lethality bioassay method and the lethal concentrations(LC50)were determined at confidence intervals by analyzing the data on a computer loaded with"Finney Programme??Results:All the vegetable extracts showed low to elevated levels of antibacterial activity against most of the tested strains(zone of inhibition=5-28 mm).The most active extract against all bacterial strains was from Xanthium indicum which showed remarkable antibacterial activity having the diameter of growth inhibition zone ranging from 12 to 28 mm followed by Alternanthera sessilis(zone of inhibition=6-21 mm).All extracts exhibited considerable general toxicity towards brine shrimps.The LC50value of the tested extracts was within the range of 8.447 to 60.323μg/mL with respect to the positive control(vincristine sulphate)which was 0.91μg/mL.Among all studied extracts,Xanthium indicum displayed the highest cytotoxic effect with LC50value of 8.447μg/mL.Conclusions:The results of the present investigation suggest that most of the studied plants are potentially good source of antibacterial and anticancer agents.

  14. Bioassay-guided isolation of proanthocyanidins with antioxidant activity from peanut (Arachis hypogaea) skin by combination of chromatography techniques.

    Science.gov (United States)

    Oldoni, Tatiane L C; Melo, Priscilla S; Massarioli, Adna P; Moreno, Ivani A M; Bezerra, Rosângela M N; Rosalen, Pedro L; da Silva, Gil V J; Nascimento, Andréa M; Alencar, Severino M

    2016-02-01

    Purification and bioassay-guided fractionation were employed to isolate proanthocyanidins with antioxidant activity from peanut skin (Arachis hypogaea Runner 886). The crude extract was prepared with acetone (60% v/v) and purified using chromatographic methods, including a semipreparative HPLC technique. As a result, two proanthocyanidins were isolated and identified using NMR, epicatechin-(2 β → O → 7, 4 β → 8)-catechin (proanthocyanidin A1) and epicatechin-(β → 2 O → 7, 4 β → 8)-epicatechin (proanthocyanidin A2). Despite the structural similarity, differences were observed in their antioxidant activity. Proanthocyanidin A1 proved to be more active, with EC50 value for DPPH radical scavenging of 18.25 μg/mL and reduction of Fe(3+)-TPTZ complex of 7.59 mmol/g, higher than that of synthetic antioxidant BHT. This compound evaluated by ABTS(+) was similar to that of natural quercetin. Therefore, peanut skin is an important source of bioactive compounds that may be used as a mild antioxidant for food preservation. PMID:26304352

  15. Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from Gymnosperma glutinosum Leaves

    Directory of Open Access Journals (Sweden)

    Cristina Rodríguez-Padilla

    2012-09-01

    Full Text Available Bioassay-guided fractionation of hexane extracts of Gymnosperma glutinosum (Asteraceae leaves, collected in North Mexico, afforded the known compounds hentriacontane (1 and (+-13S,14R,15-trihydroxy-ent-labd-7-ene (2, as well as the new ent-labdane diterpene (−-13S,14R,15-trihydroxy-7-oxo-ent-labd-8(9-ene (3. In addition, D-glycero-D-galactoheptitol (4 was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the in vitro L5178Y-R lymphoma murine model. Hentriacontane (1 and the new ent-labdane 3 showed weak cytotoxicity, whereas the ent-labdane 2 showed significant (p < 0.05 and concentration dependent cytotoxicity (up to 78% against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

  16. Development of whole sediment bioassay using the marine/estuarine polychaetes Polydora cornuta Bosc 1802 and Boccardia proboscidea Hartman 1940

    Energy Technology Data Exchange (ETDEWEB)

    Pocklington, P. [Arenicola Marine, Dartmouth, Nova Scotia (Canada); Doe, K.; Huybers, A.; Wade, S. [Environment Canada, Dartmouth, Nova Scotia (Canada). Environmental Quality Lab.; Lee, D. [Environment Canada, North Vancouver, British Columbia (Canada). Pacific Environmental Science Centre

    1995-12-31

    The growing need by Environment Canada for a battery of marine toxicity tests has prompted the development of chronic, sublethal, sediment bioassay tests using marine or estuarine annelids (polychaetes). Initially several species of polychaetes found in the Atlantic, Pacific and Arctic waters were assessed and a few of these were selected for testing survival and sensitivity under laboratory conditions and sensitivity to reference toxicants using field collected specimens. From these experiments, the authors identified several promising species and attempts were made to culture them. To date they have been successful in culturing one species from the Atlantic coast--Polydora cornuta and one species from the Pacific Coast--Boccardia proboscidea. They have been able to generate sufficient numbers of same-age larvae, raise them under controlled conditions to juveniles/young adults, and, subject them to a variety of Non-Contaminant Effects Trials (NCETs) and Contaminant Effects Trials (CETs). In the NCETs the authors determined the effect of food type and food ration, temperature, salinity, grain size, length of test condition. They found them to be moderately robust in terms of variable environmental parameters. In the CETs they found this species to be sensitive to sediments considered by Environment Canada to be toxic. They also determined the animal`s sensitivity to a reference toxicant CdCl{sub 2} (96 hr LC50).

  17. QSAR study on the non-monotonic dose-response curve of PCBs in chicken embryo hepatocyte bioassay

    Institute of Scientific and Technical Information of China (English)

    MU YunSong; ZHANG AiQian; GAO ChangAn; PENG SuFen; WANG LianSheng

    2009-01-01

    Endocrine disrupting chemicals (EDCs) in the natural environment exhibit a unique non-monotonic dose-response curve and it is impossible to select one simple index to characterize the bilogogical activity of these compounds. Quantitative structure-activity relationship (QSAR) study on non-monotonic dose-response curve has become a real challenge presently. In order to explore the possible mechanism for the non-monotonic dose-response curve of polychlorinated biphenyls con-geners (PCBs) in chicken embryo hepatocyte bioassay, AM1 method of ChemOffice was adopted to calculate necessary structure descriptors for PCBs, while the interactions between PCBs and simulated AhR ligand binding domain (LBD) were analyzed by using FlexX in SYBYL7.0. Different binding modes for PCBs have been distinguished not only from aligned conformation but also from free binding energy. Some QSAR models were established separately for both low and high doses ranges, revealing that receptor binding may predominate in the interference of the physiological function of cytochrome P4501A-P4501A in the low doses range. But with the higher doses range, the EROD suppression might he related to acute toxicity owing to molecular polarity or distribution of charges and consequently damage structure and function of chicken embryo hepatocyte.

  18. QSAR study on the non-monotonic dose-response curve of PCBs in chicken embryo hepatocyte bioassay

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Endocrine disrupting chemicals (EDCs) in the natural environment exhibit a unique non-monotonic dose-response curve and it is impossible to select one simple index to characterize the bilogogical activity of these compounds. Quantitative structure-activity relationship (QSAR) study on non-monotonic dose-response curve has become a real challenge presently. In order to explore the possible mechanism for the non-monotonic dose-response curve of polychlorinated biphenyls congeners (PCBs) in chicken embryo hepatocyte bioassay, AM1 method of ChemOffice was adopted to calculate necessary structure descriptors for PCBs, while the interactions between PCBs and simulated AhR ligand binding domain (LBD) were analyzed by using FlexX in SYBYL7.0. Different binding modes for PCBs have been distinguished not only from aligned conformation but also from free binding energy. Some QSAR models were established separately for both low and high doses ranges, revealing that receptor binding may predominate in the interference of the physiological function of cytochrome P4501A-P4501A in the low doses range. But with the higher doses range, the EROD suppression might be related to acute toxicity owing to molecular polarity or distribution of charges and consequently damage structure and function of chicken embryo hepatocyte.

  19. Development of a radioimmunoassay for Escherichia coli heat-stable enterotoxin: comparison with the suckling mouse bioassay

    International Nuclear Information System (INIS)

    Escherichia coli strains which produce heat-stable enterotoxin (ST) are usually identified by demonstrating the production of ST. At present, ST can be detected only by bioassay methods. Recently, we purified E. coli ST, which enabled us to develop a radioimmunoassay for ST. Radioiodination of ST was performed by the lactoperoxidase method, which resulted in a high specific activity and retained the biological activity of St. Anti-ST antisera were raised in goats by injecting the goats with pure ST coupled to bovine immunoglobin G. Antibody titers ranged from 1:8,000 to 1:40,000. Using these reagents, we examined assay conditions thoroughly and found that a 14- to 18-h incubation at 4 degrees C in sodium acetate buffer with an ionic strength of 120 mM (pH 6.2) gave maximal sensitivity and reproducibility. Free ST was separated from antibody-bound ST by dextran-coated charcoal. This radioimmunoassay accurately and reproducibly measured ST in the range from 50 to 500 pg of ST per tube and could quantitate ST accurately in complex bacteriological media. This assay was specific for STa, measured human and porcine STa equally well, and did not cross-react with STb, with several other enterotoxins, or with various gastrointestinal peptides. Intact disulfide bridges in the ST molecule were required for immunoreactive activity

  20. Utilizing an earthworm bioassay (Eisenia andrei) to assess a South African soil screening value with regards to effects from a copper manufacturing industry.

    Science.gov (United States)

    Maboeta, Mark; Fouché, Tanya

    2014-09-01

    Metal contamination of soil due to industrialization has become an increasingly important problem in South Africa. This study aimed to investigate the potential impact of a copper (CuSO4·5H2O) production company on the soil environment. Bioassays using Eisenia andrei were performed to assess changes in biomass, reproduction and a biomarker, neutral red retention time, over a 28 day period. Earthworms exposed to soils from the Cu production site differed significantly (p < 0.05) from those exposed to soils 500 m and 5 km away in terms of the measured endpoints. These findings are consistent with the results from the chemical analysis which showed an elevated soil Cu content for both sites closest to the chemical production company compared to the reference site. The results confirm the importance and predictive value of using bioassays in conjunction with chemical analysis during soil quality assessments. PMID:24875827

  1. Improvement of Teaching Experimental Design of Pesticide Bioassays%农药毒力测定教学试验设计的改进

    Institute of Scientific and Technical Information of China (English)

    王静; 陈斌; 肖春; 叶敏; 范黎明; 查友贵

    2013-01-01

    For mistakes taken in pesticide bioassays, teaching experimental design was improved in the paper, so as to let students explore and analyze in teaching experiment to get a deeper understanding of theoretical knowledge, thereby effectively avoiding frequently-taken mistakes in pesticide bioassays.%针对农药毒力测定中经常出现的错误,对农药毒力测定教学试验设计进行了改进,使学生在试验教学中探索与分析,从而加深了对理论知识的理解,有效避免了农药毒力测定中该类错误的频繁发生.

  2. Development of a Competitive Cystatin C-Specific Bioassay Suitable for Repetitive Measurements.

    Directory of Open Access Journals (Sweden)

    Tatjana Damm

    Full Text Available Human cystatin C (hCC, a cysteine protease inhibitor, has been proposed as a diagnostic marker because its serum levels correlate with certain cardiovascular and kidney diseases. All current hCC assays are based on ex vivo detection. Here we describe the generation and evaluation of antibodies that allow the repetitive binding and release of hCC and hCC-fusion proteins, a prerequisite for long-term measurement, which is required for compatibility with implantable biochip devices and for the development of innovative antibody-based assays suitable for continuous in vivo and in vitro monitoring. Recombinant hCC and hCC-fusion proteins were produced in Escherichia coli and HEK293T cells and were used to generate antibodies by hybridoma technology. After screening by indirect and sandwich ELISAs, 12 monoclonal hybridoma cell lines producing hCC-specific monoclonal antibodies were identified. To determine their hCC association and dissociation properties, the antibodies were analysed by surface plasmon resonance spectroscopy, revealing three with the desired fast binding and moderate-to-fast release characteristics. The analysis of binding and dissociation in the presence of hCC and hCC-fusion proteins using fluorescence-based replacement assays showed that mAb CyDI-4 was the most suitable for further analysis. The results showed that repetitive replacement on mAb CyDI-4 was possible and that most of the change in signal intensity occurred after 20-30 min. Furthermore, the suitability of mAb CyDI-4 for serum hCC measurement was confirmed by a fluorescence-based replacement assay using serially-diluted reference serum from the Institute for Reference Materials and Measurements (ERM-DA471/IFCC. Our results suggest that the assay covers the physiological and pathological ranges of hCC.

  3. Bioassay-Guided Fractionation of Extracts from Codiaeum variegatum against Entamoeba histolytica Discovers Compounds That Modify Expression of Ceramide Biosynthesis Related Genes

    OpenAIRE

    Emmanuel Mfotie Njoya; Christian Weber; Nora Adriana Hernandez-Cuevas; Chung-Chau Hon; Yves Janin; Kamini, Melanie F G; Moundipa, Paul F; Nancy Guillén

    2014-01-01

    International audience Leaves of Codiaeum variegatum ("garden croton") are used against bloody diarrhoea by local populations in Cameroon. This study aims to search for the active components from C. variegatum against Entamoeba histolytica, and thereby initiate the study of their mechanism of action. A bioassay-guided screening of the aqueous extracts from C. variegatum leaves and various fractions was carried out against trophozoites of E. histolytica axenic culture. We found that the ant...

  4. Potency determination of follitropin, lutropin And thyrotropin: a comparison between the quantification by reversed-phase high-performance liquid chromatography and in vivo bioassay

    International Nuclear Information System (INIS)

    With the intention of setting up physico-chemical methods as an alternative to in vivo bioassay for determining biological activity, the hFSH, hTSH and hLH content of native and recombinant preparations was determined by reversed-phase high-performance liquid chromatography (RP-HPLC) and compared with the data obtained by the classical mouse or rat in vivo bioassays (BA). A linear relationship between the two methods was found for these hormones: hFSH BAU= 0.9925 RP-HPLCU– 1.3165, r = 0.9371, p IU = 0.8771 RP-HPLCIU + 12.41, r = 0.9786, p < 0.01, n = 5. For nine other hFSH and eleven hTSH preparations, the mean difference ( ) between the bioactivity predicted from RP-HPLC data via these equations and the mean of the bioactivities obtained with the two methods was as follows. For hLH this difference could not be estimated due to lack of different samples. In the case of hFSH, ± SD = -2.11 ± 3.49% with a precision of 1.16% and in the case of hTSH, ± SD = -2.01 ± 5.56 %, with precision of 1.68%. Partly-degraded hFSH, hTSH and hLH samples presented different activity degrees that could be predicted by RP-HPLC, with an acceptable agreement with the in vivo bioassays. These results demonstrate that the employment of a non-animal physico-chemical assay, such as RP-HPLC, is a viable alternative to the use of an in vivo bioassay for hFSH and hTSH potency determination, thus reducing the number of animals currently used for assuring quality and efficacy of a pharmaceutical product. (author)

  5. Low-Cost Photolithographic Fabrication of Nanowires and Microfilters for Advanced Bioassay Devices

    Directory of Open Access Journals (Sweden)

    Nhi M. Doan

    2015-03-01

    Full Text Available Integrated microfluidic devices with nanosized array electrodes and microfiltration capabilities can greatly increase sensitivity and enhance automation in immunoassay devices. In this contribution, we utilize the edge-patterning method of thin aluminum (Al films in order to form nano- to micron-sized gaps. Evaporation of high work-function metals (i.e., Au, Ag, etc. on these gaps, followed by Al lift-off, enables the formation of electrical uniform nanowires from low-cost, plastic-based, photomasks. By replacing Al with chromium (Cr, the formation of high resolution, custom-made photomasks that are ideal for low-cost fabrication of a plurality of array devices were realized. To demonstrate the feasibility of such Cr photomasks, SU-8 micro-pillar masters were formed and replicated into PDMS to produce micron-sized filters with 3–4 µm gaps and an aspect ratio of 3. These microfilters were capable of retaining 6 µm beads within a localized site, while allowing solvent flow. The combination of nanowire arrays and micro-pillar filtration opens new perspectives for rapid R&D screening of various microfluidic-based immunoassay geometries, where analyte pre-concentration and highly sensitive, electrochemical detection can be readily co-localized.

  6. Comparison of the Artemia salina and Artemia fransiscana bioassays for toxicity of Indian medicinal plants

    Directory of Open Access Journals (Sweden)

    Thangapandi Veni

    2014-06-01

    Full Text Available Objective: To evaluate leaves extract of Azima tetracantha and Gmelina asiatica for lethality to brine shrimp larvae (Artemia salina and Artemia fransiscana. Methods: The plant materials were extracted based on polarity gradients of petroleum ether, benzene, chloroform, acetone, ethanol and methanol. The extracts were investigated for their cytotoxic potential. Results: In the brine shrimp lethality assay of all extracts, exception of acetone, ethanol and petroleum ether extracts Gmelina asiatica displayed 100% mortality at 1 000 μg/mL by Artemia salina and Artemia fransiscana. Chloroform extract was the most potent and presented the highest percentage of mortality with the lowest LC50 values by both assay too. Conclusions: The results of the present study suggest the presence of photochemical possessing cytotoxic agents.

  7. Comparison of the Artemia salina and Artemia fransiscana bioassays for toxicity of Indian medicinal plants

    Institute of Scientific and Technical Information of China (English)

    Thangapandi Veni; Thambusamy Pushpanathan

    2014-01-01

    Objective:To evaluate leaves extract of Azima tetracantha and Gmelina asiatica for lethality to brine shrimp larvae (Artemia salina and Artemia fransiscana). Methods: The plant materials were extracted based on polarity gradients of petroleum ether, benzene, chloroform, acetone, ethanol and methanol. The extracts were investigated for their cytotoxic potential. Results: In the brine shrimp lethality assay of all extracts, exception of acetone, ethanol and petroleum ether extracts Gmelina asiatica displayed 100%mortality at 1 000 μg/mL by Artemia salina and Artemia fransiscana. Chloroform extract was the most potent and presented the highest percentage of mortality with the lowest LC50 values by both assay too. Conclusions:The results of the present study suggest the presence of photochemical possessing cytotoxic agents.

  8. Profiling of benzophenone derivatives using fish and human estrogen receptor-specific in vitro bioassays

    International Nuclear Information System (INIS)

    Benzophenone (BP) derivatives, BP1 (2,4-dihydroxybenzophenone), BP2 (2,2',4,4'-tetrahydroxybenzophenone), BP3 (2-hydroxy-4-methoxybenzophenone), and THB (2,4,4'-trihydroxybenzophenone) are UV-absorbing chemicals widely used in pharmaceutical, cosmetics, and industrial applications, such as topical sunscreens in lotions and hair sprays to protect skin and hair from UV irradiation. Studies on their endocrine disrupting properties have mostly focused on their interaction with human estrogen receptor alpha (hERα), and there has been no comprehensive analysis of their potency in a system allowing comparison between hERα and hERβ activities. The objective of this study was to provide a comprehensive ER activation profile of BP derivatives using ER from human and fish origin in a battery of in vitro tests, i.e., competitive binding, reporter gene based assays, vitellogenin (Vtg) induction in isolated rainbow trout hepatocytes, and proliferation based assays. The ability to induce human androgen receptor (hAR)-mediated reporter gene expression was also examined. All BP derivatives tested except BP3 were full hERα and hERβ agonists (BP2 > THB > BP1) and displayed a stronger activation of hERβ compared with hERα, the opposite effect to that of estradiol (E2). Unlike E2, BPs were more active in rainbow trout ERα (rtERα) than in hERα assay. All four BP derivatives showed anti-androgenic activity (THB > BP2 > BP1 > BP3). Overall, the observed anti-androgenic potencies of BP derivatives, together with their proposed greater effect on ERβ versus ERα activation, support further investigation of their role as endocrine disrupters in humans and wildlife

  9. Aryl hydrocarbon receptor (AhR) inducers and estrogen receptor (ER) activities in surface sediments of Three Gorges Reservoir, China evaluated with in vitro cell bioassays.

    Science.gov (United States)

    Wang, Jingxian; Bovee, Toine F H; Bi, Yonghong; Bernhöft, Silke; Schramm, Karl-Werner

    2014-02-01

    Two types of biological tests were employed for monitoring the toxicological profile of sediment cores in the Three Gorges Reservoir (TGR), China. In the present study, sediments collected in June 2010 from TGR were analyzed for estrogen receptor (ER)- and aryl hydrocarbon receptor (AhR)-mediated activities. The estrogenic activity was assessed using a rapid yeast estrogen bioassay, based on the expression of a green fluorescent reporter protein. Weak anti-estrogenic activity was detected in sediments from an area close to the dam of the reservoir, and weak estrogenic activities ranging from 0.3 to 1 ng 17β-estradiol (E2) equivalents (EQ) g(-1) dry weight sediment (dw) were detected in sediments from the Wanzhou to Guojiaba areas. In the upstream areas Wanzhou and Wushan, sediments demonstrated additive effects in co-administration of 1 nM E2 in the yeast test system, while sediments from the downstream Badong and Guojiaba areas showed estrogenic activities which seemed to be more than additive (synergistic activity). There was an increasing tendency in estrogenic activity from upstream of TGR to downstream, while this tendency terminated and converted into anti-estrogenic activity in the area close to the dam. The AhR activity was detected employing rat hepatoma cell line (H4IIE). EROD activities were found homogenously distributed in sediments in TGR ranging from 200 to 311 pg 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) EQ g(-1) dw for total AhR agonists and from 45 to 76 pg TCDD EQ g(-1) dw for more persistent AhR agonists. The known AhR agonists polycyclic aromatic hydrocarbon, polychlorinated biphenyl, and PCDD/F only explained up to 8 % of the more persistent AhR agonist activity in the samples, which suggests that unidentified AhR-active compounds represented a great proportion of the TCDD EQ in sediments from TGR. These findings of estrogenic potential and dioxin-like activity in TGR sediments provide possible weight-of-evidence of potential

  10. Bioassays to monitor Taspase1 function for the identification of pharmacogenetic inhibitors.

    Directory of Open Access Journals (Sweden)

    Shirley K Knauer

    Full Text Available BACKGROUND: Threonine Aspartase 1 (Taspase1 mediates cleavage of the mixed lineage leukemia (MLL protein and leukemia provoking MLL-fusions. In contrast to other proteases, the understanding of Taspase1's (pathobiological relevance and function is limited, since neither small molecule inhibitors nor cell based functional assays for Taspase1 are currently available. METHODOLOGY/FINDINGS: Efficient cell-based assays to probe Taspase1 function in vivo are presented here. These are composed of glutathione S-transferase, autofluorescent protein variants, Taspase1 cleavage sites and rational combinations of nuclear import and export signals. The biosensors localize predominantly to the cytoplasm, whereas expression of biologically active Taspase1 but not of inactive Taspase1 mutants or of the protease Caspase3 triggers their proteolytic cleavage and nuclear accumulation. Compared to in vitro assays using recombinant components the in vivo assay was highly efficient. Employing an optimized nuclear translocation algorithm, the triple-color assay could be adapted to a high-throughput microscopy platform (Z'factor = 0.63. Automated high-content data analysis was used to screen a focused compound library, selected by an in silico pharmacophor screening approach, as well as a collection of fungal extracts. Screening identified two compounds, N-[2-[(4-amino-6-oxo-3H-pyrimidin-2-ylsulfanyl]ethyl]benzenesulfonamide and 2-benzyltriazole-4,5-dicarboxylic acid, which partially inhibited Taspase1 cleavage in living cells. Additionally, the assay was exploited to probe endogenous Taspase1 in solid tumor cell models and to identify an improved consensus sequence for efficient Taspase1 cleavage. This allowed the in silico identification of novel putative Taspase1 targets. Those include the FERM Domain-Containing Protein 4B, the Tyrosine-Protein Phosphatase Zeta, and DNA Polymerase Zeta. Cleavage site recognition and proteolytic processing of these substrates were

  11. {sup 99}Tc bioassay by inductively coupled plasma mass spectrometry (ICP-MS)

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, L.A.

    1998-05-01

    A means of analyzing {sup 99}Tc in urine by inductively coupled plasma mass spectrometry (ICP-MS) has been developed. Historically, {sup 99}Tc analysis was based on the radiometric detection of the 293 keV E{sub Max} beta decay product by liquid scintillation or gas flow proportional counting. In a urine matrix, the analysis of{sup 99}Tc is plagued with many difficulties using conventional radiometric methods. Difficulties originate during chemical separation due to the volatile nature of Tc{sub 2}O{sub 7} or during radiation detection due to color or chemical quenching. A separation scheme for {sup 99}Tc detection by ICP-MS is given and is proven to be a sensitive and robust analytical alternative. A comparison of methods using radiometric and mass quantitation of {sup 99}Tc has been conducted in water, artificial urine, and real urine matrices at activity levels between 700 and 2,200 dpm/L. Liquid scintillation results based on an external standard quench correction and a quench curve correction method are compared to results obtained by ICP-MS. Each method produced accurate results, however the precision of the ICP-MS results is superior to that of liquid scintillation results. Limits of detection (LOD) for ICP-MS and liquid scintillation detection are 14.67 and 203.4 dpm/L, respectively, in a real urine matrix. In order to determine the basis for the increased precision of the ICP-MS results, the detection sensitivity for each method is derived and measured. The detection sensitivity for the {sup 99}Tc isotope by ICP-MS is 2.175 x 10{sup {minus}7} {+-} 8.990 x 10{sup {minus}9} and by liquid scintillation is 7.434 x 10{sup {minus}14} {+-} 7.461 x 10{sup {minus}15}. A difference by seven orders of magnitude between the two detection systems allows ICP-MS samples to be analyzed for a period of 15 s compared to 3,600 s by liquid scintillation counting with a lower LOD.

  12. Cytotoxicity evaluation and hepatoprotective potential of bioassay guided fractions from Feronia limmonia Linn leaf

    Institute of Scientific and Technical Information of China (English)

    Mahendra Jain; Rakhee Kapadia; Ravirajsinh N Jadeja; Menaka C Thounaojam; Ranjitsinh V Devkar; SH Mishra

    2011-01-01

    To evaluate the cytotoxicity and hepatoprotective potentials of extracts, fractions or isolated compound from the leaves of Feronia limonia (F. limonia). Methods: Qualitative phytochemical analysis of extracts, fractions or compound was performed by means of thin layer chromatography and spectroscopic assays. The % purity of compound was measured by analytical HPLC. Extracts, fractions or compound have been individually evaluated for their cytotoxicity effects (10, 20, 100, 250, 500, 750 and 1 000 μg/mL). Based on the inhibitory concentration (IC50) obtained from the cell viability assay, graded concentrations of extracts, fractions or isolated compound were assessed (10, 20, 50, 100, 200 μg/mL) for its hepatoprotective potential against CCl4-induced hepatotoxicity by monitoring activity levels of serum glutamatic pyruvatic transaminase (SGPT) and serum glutamic oxaloacetic transaminase (SGOT). Results: Results indicated that the methanol extract of F. limonia was non-toxic and hepatoprotective in nature as compared with the petroleum ether extract. The acetone fraction of methanolic extract also showed similar properties but the subsequent two fractions were cytotoxic. However, the pure compound isolated from the penultimate fraction of methanolic extract was non-toxic and hepatoprotective in nature. Biochemical investigations (SGOT, SGPT) further corroborated these cytological observations. Conclusions: It can be concluded from this study that F. limonia methanol extract, some fractions and pure isolated compound herein exhibit hepatoprotective activity. However, cytotoxicity recorded in the penultimate fraction and investigation of structural details of pure compound warrants further study.

  13. A biological safety evaluation on reclaimed water reused as scenic water using a bioassay battery

    Institute of Scientific and Technical Information of China (English)

    Dongbin Wei; Zhuowei Tan; Yuguo Du

    2011-01-01

    An assessment method based on three toxicity tests (algae growth inhibition,daphnia immobilization and larval fish toxicity) was used to screen the biological safety of reclaimed water which was reused as sole replenishment for scenic water system in a park (SOF Park) in northern China.A total of 24 water samples were collected from six sites of water system in the SOF Park in four different seasons.The results indicated that:(1) the reclaimed water directly discharged from a reclamation treatment plant near the SOF Park as influent of park had relatively low biological safety (all samples were ranked as C or D); (2) the biological safety of reclaimed water was improved greatly with the ecological reclamation treatment processes composing of artificial wetland system and followed oxidation pond system; (3) the biological safety of reclaimed water in the main lake of SOF Park kept at a health status during different seasons (all samples were ranked as A); (4) there was some certain correlation (R2 =0.5737) between the sum of toxicity scores and dissolved organic carbon for the studied water samples.It was concluded that the assessment method was reliable to screen the safety of reclaimed water reused as scenic water,and the reclaimed water with further ecological purification processes such as artificial wetland and oxidation pond system can be safely reused as scenic water in park.

  14. Bioassay program: determination of I-131 body burden among radiation workers and nuclear medicine laboratory technicians

    Energy Technology Data Exchange (ETDEWEB)

    Duran, E.B.; Napenas, D.; San Jose, V.; Juan, N.

    The body burden of I-131 was determined among the radiation workers of the Philippine Atomic Energy Commission (PAEC) who are directly involved in I-131 processing and nuclear laboratory technicians of University of Santo Tomas and Veterans Hospital, who handle and dispense I-131 to patients. The routine monitoring was done by urine analysis. The untreated urine samples were counted directly for 4000 seconds using Nal(Tl) scintillation detector coupled to an ND66 microcomputer-based multichannel analyzer. Urine samples of radiation workers of PAEC who are not involved in I-131 processing and non-radiation workers were also assayed for comparison. For radiation workers of PAEC who are directly involved in processing I-131, the estimated body burden of I-131 ranged from <0.055 to 8.53 uCi (282 urine samples). These values were higher than those observed for radiation workers not involved in the handling or processing of I-131 with estimated body burden of I-131 ranging from <0.055 to 0.52 uCi (48 urine samples) or than those observed from non-radiation workers (<0.055 uCi). The maximum permissible burden of I-131 is 0.7 uCi.

  15. Microphytobenthos in ecotoxicology: a review of the use of marine benthic diatoms in bioassays.

    Science.gov (United States)

    Araújo, Cristiano V M; Blasco, Julián; Moreno-Garrido, Ignacio

    2010-08-01

    Contamination in coastal zones is an increasing problem that adversely affects biological diversity and the functioning of coastal ecosystems. Sediment is an important compartment of these zones since large quantities of diverse contaminants can accumulate there. Whole-sediment toxicity assays are of increasing importance, and several assay methods using mainly invertebrates have been developed. However, an important part of the benthic community, the microphytobenthos (represented principally by benthic diatoms and cyanobacteria), has surprisingly been neglected. Recently, comprehensive studies have been conducted using benthic marine microalgae with the object of establishing a toxicity assay method for sediment samples. The main results published to date in the literature and obtained by our own team have been compiled and are discussed in this review. The value and feasibility of using certain organisms of the microphytobenthos group in ecotoxicology studies are also discussed, and a sediment quality guideline based on multivariate procedure has been derived from data obtained in previous studies. Finally, future perspectives for research in this field are discussed. PMID:20493528

  16. Application of a canine 238Pu biokinetics/dosimetry model to human bioassay data.

    Science.gov (United States)

    Hickman, A W; Griffith, W C; Roessler, G S; Guilmette, R A

    1995-03-01

    Associated with the use of 238Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as 238PuO2. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to 239Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of 238Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a 238Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of 238Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces. PMID:7860307

  17. Multifunctional carbon nanotubes for direct electrochemistry of glucose oxidase and glucose bioassay.

    Science.gov (United States)

    Wang, Yinling; Liu, Lin; Li, Maoguo; Xu, Shudong; Gao, Feng

    2011-12-15

    Polydopamine (Pdop) has recently been shown to adsorb to a wide variety of surfaces and serves as an adhesion layer to immobilize biological molecules. In this work, the multifunctional carbon nanotube (CNT) composites were prepared though the oxidation of dopamine at room temperature and subsequent electroless silver deposition by mildly stirring. The stable immobilization and direct electron transfer of glucose oxidase were achieved on the composite film modified glassy carbon electrode. The resulting electrode gave a well-defined redox peaks with a formal potential of about -482 mV (vs. SCE) in pH 7.0 buffer. The electron transfer rate constant was estimated to be 3.6 s(-1), due to the combined contribution of Pdop, CNTs and Ag nanoparticles with the help of Nafion. Furthermore, the method for detecting of glucose was proposed based on the decrease of oxygen caused by the enzyme-catalyzed reaction between glucose oxidase (GOD) and glucose. The linear response to glucose ranging from 50.0 μM to 1.1 mM (R(2)=0.9958), with a calculated detection limit of 17.0 μM at a signal-to-noise ratio of 3. The low calculated apparent Michaelis-Menten constant (K(M)(app)) was 5.46 mM, implying the high enzymatic activity and affinity of immobilized GOD for glucose. It can reasonably be expected that this observation might hold true for other noble metal nanostructure-electroactive protein systems, providing a promising platform for the development of biosensors and biofuel cells. PMID:21959226

  18. Establishment of a bioassay system for cancer risk assessment in energy technology

    Energy Technology Data Exchange (ETDEWEB)

    Ts' o, P.O.P.; Bruce, S.A.; Brown, A. (eds.)

    1983-09-01

    Separate abstracts were prepared for 20 papers in this report. For several years the Department of Energy (DOE), Office of Health and Environmental Research (OHER), has supported a research program aimed at developing new experimental approaches for the improvement of cancer risk assessments. The central issue is to overcome the organizational, species and other barriers that make it difficult to extrapolate laboratory-based data to predict risk to man. Most of the participants at the meeting are involved in research aimed at understanding the mechanism(s) of chemical carcinogenesis. Complex mixtures of chemicals are associated with many energy technologies. DOE's initial program emphasis focused on semi-applied research aimed at quantitative evaluation of carcinogenic activity of complex materials. Since much progress has been made in DOE integrated technology-specific chemical-biological characterization studies, the number and kinds of chemicals of concern has been reduced to a relatively few well-defined classes. Although the classes of compounds seem to be unique to some of the synfuel technologies, they are quite similar to compounds of general interest, for example, poly-nuclear aromatic hydrocarbons. Special emphasis was placed on molecular and cellular dosimetry as one of the key requirements for quantitative comparison of effects at the cell level in vivo and in vitro. Although it is relatively easy to measure cell, tissue, organ and whole organism doses associated with radiation exposures, we are just learning how to do this for chemical agents. Several methods have been developed in the past several years which can be used.

  19. Effect of iodination on human growth hormone and prolactin: characterized by bioassay, radioimmunoassay, radioreceptor assay, and electrophoresis

    International Nuclear Information System (INIS)

    Human GH (hGH) and PRL (hPRL) were iodinated using lactoperoxidase. The iodinated hormones were characterized by RIA, radioreceptor assay (RRA), and bioassay (BA) using the Nb2 Node lymphoma cell line. The proportion of tracer that could bind to rat liver membranes or rabbit antibodies was determined, and the distribution of iodinated hormones was examined using polyacrylamide gel electrophoresis. Excess antibody was capable of precipitating 87.9% of the radioactivity associated with the hGH tracer and 86.0% of the hPRL tracer. The maximal specific binding to a liver membrane preparation averaged 67.3% of the [125I]iodo-hGH radioactivity and 48.8% of the [125I]iodo-hPRL radioactivity. The respective BA and RRA activity estimates for [125]iodo-hGH averaged 90% and 114% of the activity measured by the RIA. For [125I]iodo-hPRL, the values were 75% by BA and 68% by RRA. The bioactivity profiles of iodinated hGH and hPRL shifted anodally on polyacrylamide gel electrophoresis in comparison to the bioactivity distribution of the respective uniodinated hormones. Iodine incorporation rather than oxidation appeared to be responsible for the shift. After electrophoresis, all eluates which contained significant radioactivity were active in the BA and RIA. Furthermore, specific activities calculated from the bioactive hormone and radioactivity in each electrophoretic segment agreed well with the average specific activity estimated from the amount of iodine incorporated into the protein peak upon gel filtration. These data suggest that hGH and hPRL to a major degree retain biological integrity after iodination

  20. Calibrating Self-Reported Measures of Maternal Smoking in Pregnancy via Bioassays Using a Monte Carlo Approach

    Directory of Open Access Journals (Sweden)

    Lauren S. Wakschlag

    2009-06-01

    Full Text Available Maternal smoking during pregnancy is a major public health problem that has been associated with numerous short- and long-term adverse health outcomes in offspring. However, characterizing smoking exposure during pregnancy precisely has been rather difficult: self-reported measures of smoking often suffer from recall bias, deliberate misreporting, and selective non-disclosure, while single bioassay measures of nicotine metabolites only reflect recent smoking history and cannot capture the fluctuating and complex patterns of varying exposure of the fetus. Recently, Dukic et al. [1] have proposed a statistical method for combining information from both sources in order to increase the precision of the exposure measurement and power to detect more subtle effects of smoking. In this paper, we extend the Dukic et al. [1] method to incorporate individual variation of the metabolic parameters (such as clearance rates into the calibration model of smoking exposure during pregnancy. We apply the new method to the Family Health and Development Project (FHDP, a small convenience sample of 96 predominantly working-class white pregnant women oversampled for smoking. We find that, on average, misreporters smoke 7.5 cigarettes more than what they report to smoke, with about one third underreporting by 1.5, one third under-reporting by about 6.5, and one third underreporting by 8.5 cigarettes. Partly due to the limited demographic heterogeneity in the FHDP sample, the results are similar to those obtained by the deterministic calibration model, whose adjustments were slightly lower (by 0.5 cigarettes on average. The new results are also, as expected, less sensitive to assumed values of cotinine half-life.