Publications & Documents


  • 28-July-2015

    English

    Test No. 455: Performance-Based Test Guideline for Stably Transfected Transactivation In Vitro Assays to Detect Estrogen Receptor Agonists and Antagonists

    This Performance-Based Test Guideline (PBTG) describes in vitro assays, which provide the methodology of Stably Transfected Transactivation to detect Estrogen Receptor Agonists and Antagonists (ER TA assays). It comprises mechanistically and functionally similar test methods for the identification of estrogen receptor agonists and antagonists and should facilitate the development of new similar or modified test methods. The two reference test methods that provide the basis for this PBTG are: the Stably Transfected TA (STTA) assay using the (h) ERα-HeLa-9903 cell line, derived from a human cervical tumor, and the BG1Luc ER TA assay using the BG1Luc-4E2 cell line, derived from a human ovarian adenocarcinoma. The cell lines used in these assays express ER and have been stably transfected with an ER responsive luciferase reporter gene. The assays are used to identify chemicals that activate (i.e. act as agonists) and also suppress (i.e. act as antagonists) ER- dependent transcription. ER are activated following ligand binding, after which the receptor-ligand complex binds to specific DNA response elements and transactivates the reporter gene, resulting in increased cellular expression of a marker enzyme (e.g. luciferase in luciferase based systems). The enzyme then transforms the substrate to a bioluminescent product that can be quantitatively measured with a luminometer. These test methods are being proposed for screening and prioritisation purposes, but also provide mechanistic information that can be used in a weight of evidence approach.

  • 28-July-2015

    English

    Test No. 431: In vitro skin corrosion: reconstructed human epidermis (RHE) test method

    The test described in this Test Guideline allows the identification of corrosive chemical substances and mixtures and it enables the identification of non-corrosive substances and mixtures when supported by a weight of evidence determination using other existing information. The test protocol may also provide an indication of the distinction between severe and less severe skin corrosives. This Test Guideline does not require the use of live animals or animal tissue for the assessment of skin corrosivity.

    The test material (solid or liquid) is applied uniformly and topically to a three-dimensional human skin model, comprising at least a reconstructed epidermis with a functional stratum corneum. Two tissue replicates are used for each treatment (exposure time), and for controls. Corrosive materials are identified by their ability to produce a decrease in cell viability below defined threshold levels at specified exposure periods. Coloured chemicals can also be tested by used of an HPLC procedure. The principle of the human skin model assay is based on the hypothesis that corrosive chemicals are able to penetrate the stratum corneum by diffusion or erosion, and are cytotoxic to the underlying cell layers.

  • 28-July-2015

    English

    Test No. 491: Short Time Exposure In Vitro Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage

    This Test Guideline describes a cytotoxicity-based in vitro assay that is performed on a confluent monolayer of Statens Seruminstitut Rabbit Cornea (SIRC) cells, cultured on a 96-well polycarbonate microplate. After five-minute exposure to a test chemical, the cytotoxicity is quantitatively measured as the relative viability of SIRC cells using the MTT assay. Decreased cell viability is used to predict potential adverse effects leading to ocular damage. Cell viability is assessed by the quantitative measurement, after extraction from the cells, of blue formazan salt produced by the living cells by enzymatic conversion of the vital dye MTT, also known as Thiazolyl Blue Tetrazolium Bromide. The obtained cell viability is compared to the solvent control (relative viability) and used to estimate the potential eye hazard of the test chemical. A test chemical is classified as UN GHS Category 1 when both the 5% and 0.05% concentrations result in a cell viability smaller than or equal to (≤) 70%. Conversely, a chemical is predicted as UN GHS No Category when both 5% and 0.05% concentrations result in a cell viability higher than (>) 70%.

  • 28-July-2015

    English

    Test No. 483: Mammalian Spermatogonial Chromosomal Aberration Test

    This test measures structural chromosomal aberrations (both chromosome- and chromatid-type) in dividing spermatogonial germ cells and is, therefore, expected to be predictive of induction of heritable mutations in these germ cells. The purpose of the in vivo mammalian spermatogonial chromosomal aberration test is to identify those chemicals that cause structural chromosomal aberrations in mammalian spermatogonial cells (1) (2) (3). In addition, this test is relevant to assessing genetoxicity because, although they may vary among species, factors of in vivo metabolism, pharmacokinetics and DNA-repair processes are active and contribute to the response.

    The original Test Guideline 483 was adopted in 1997. This modified version of the Test Guideline reflects many years of experience with this assay and the potential for integrating or combining this test with other toxicity or genotoxicity studies.

  • 28-July-2015

    English

    Test No. 493: Performance-Based Test Guideline for Human Recombinant Estrogen Receptor (hrER) In Vitro Assays to Detect Chemicals with ER Binding Affinity

    This Performance-Based Test Guideline (PBTG) describes in vitro assays, which provide the methodology for human recombinant in vitro assays to detect substances with estrogen receptor binding affinity (hrER binding assays). It comprises two mechanistically and functionally similar test methods for the identification of estrogen receptor (i.e. ERα) binders and should facilitate the development of new similar or modified test methods. The two reference test methods that provide the basis for this PBTG are: the Freyberger-Wilson (FW) In Vitro Estrogen Receptor (ER) Binding Assay Using a Full Length Human Recombinant ERα, and the Chemical Evaluation and Research Institute (CERI) In Vitro Estrogen Receptor Binding Assay Using a Human Recombinant Ligand Binding Domain Protein. This assay measures the ability of a radiolabeled ligand ([3H]17β-estradiol) to bind with the ER in the presence of increasing concentrations of a test chemical (i.e. competitor).  Test chemicals that possess a high affinity for the ER compete with the radiolabeled ligand at a lower concentration as compared with those chemicals with lower affinity for the receptor. This assay consists of two major components: a saturation binding experiment to characterise receptor-ligand interaction parameters and document ER specificity, followed by a competitive binding experiment that characterises the competition between a test chemical and a radiolabeled ligand for binding to the ER. These test methods are being proposed for screening and prioritisation purposes, but also provide mechanistic information that can be used in a weight of evidence approach.

  • 28-July-2015

    English

    Test No. 476: In Vitro Mammalian Cell Gene Mutation Tests using the Hprt and xprt genes

    The in vitro mammalian cell gene mutation test can be used to detect gene mutations induced by chemical substances. In this test, the used genetic endpoints measure mutation at hypoxanthine-guanine phosphoribosyl transferase (HPRT), and at a transgene of xanthineguanine phosphoribosyl transferase (XPRT). The HPRT and XPRT mutation tests detect different spectra of genetic events.

    Cells in suspension or monolayer culture are exposed to, at least four analysable concentrations of the test substance, both with and without metabolic activation, for a suitable period of time. They are subcultured to determine cytotoxicity and to allow phenotypic expression prior to mutant selection. Cytotoxicity is usually determined by measuring the relative cloning efficiency (survival) or relative total growth of the cultures after the treatment period. The treated cultures are maintained in growth medium for a sufficient period of time, characteristic of each selected locus and cell type, to allow near-optimal phenotypic expression of induced mutations. Mutant frequency is determined by seeding known numbers of cells in medium containing the selective agent to detect mutant cells, and in medium without selective agent to determine the cloning efficiency (viability). After a suitable incubation time, colonies are counted.

  • 28-July-2015

    English

    Test No. 241: The Larval Amphibian Growth and Development Assay (LAGDA)

    The test guideline of the Larval Amphibian Growth and Development Assay (LAGDA) describes a toxicity test with an amphibian species (African clawed frog (Xenopus laevis)) that considers growth and development from fertilization through the early juvenile period.  It is an assay (typically 16 weeks) that assesses early development, metamorphosis, survival, growth, and partial reproductive maturation. It also enables measurement of a suite of other endpoints that allows for diagnostic evaluation of suspected endocrine disrupting chemicals (EDCs) or other types of developmental and reproductive toxicants. The LAGDA serves as a higher tier test with an amphibian for collecting more comprehensive concentration-response information on adverse effects suitable for use in hazard identification and characterization, and in ecological risk assessment. The general experimental design entails exposing X. laevis embryos at Nieuwkoop and Faber (NF) stage 8-10 (3) to a minimum of four different concentrations of test chemical and control(s) until 10 weeks after the median time to NF stage 62.  There are four replicates in each test concentration with eight replicates for the control. Endpoints evaluated during the course of the exposure (at the interim sub-sample and final sample at completion of the test) include those indicative of generalized toxicity: mortality, abnormal behaviour, and growth determinations (length and weight), as well as endpoints designed to characterize specific endocrine toxicity modes of action targeting oestrogen, androgen or thyroid-mediated physiological processes.

  • 28-July-2015

    English

    Test No. 422: Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test

    This screening Test Guideline describes the effects of a test chemical on male and female reproductive performance. It has been updated with endocrine disruptor endpoints, in particular measure of anogenital distance and male nipple retention in pups and thyroid examination.

    The test substance is administered in graduated doses to several groups of males and females. Males should be dosed for a minimum of four weeks. Females should be dosed throughout the study, so approximately 63 days. Matings "one male to one female" should normally be used in this study. This Test Guideline is designed for use with the rat. It is recommended that each group be started with at least 10 animals of each sex. Generally, at least three test groups and a control group should be used. Dose levels may be based on information from acute toxicity tests or on results from repeated dose studies. The test substance is administered orally and daily. The results of this study include clinical observations, body weight and food/water consumption, oestrous cycle monitoring, offspring parameters observation/measurement, thyroid hormone measurement, as well as gross necropsy and histopathology. The findings of this toxicity study should be evaluated in terms of the observed effects, necropsy and microscopic findings. Because of the short period of treatment of the male, the histopathology of the testis and epididymus should be considered along with the fertility data, when assessing male reproductive effects.

  • 27-July-2015

    English

    Towards Green Growth? - Tracking Progress

    The 2011 Green Growth Strategy provided initial guidance to governments on how to achieve economic growth and development, while preventing costly environmental damage and inefficient resource use. What progress have countries made in aligning economic and environmental priorities since 2011? This report attempts to evaluate this progress and highlight where there is broad scope to heighten the ambition and effectiveness of green growth policy. It draws lessons from green growth mainstreaming across the OECD’s work programme, notably in terms of how governments can maximise institutional settings to seize economic opportunities surrounding the transition to a green economy, and considers ways to enrich the Green Growth Strategy based on work undertaken since its launch.

  • 27-July-2015

    English

    Webinar: Towards Green Growth? Official Launch of the OECD's Tracking Progress Report

    On July 27, 2015 from 15:00 to 16:30 Paris time, the Green Growth Knowledge Platform (GGKP) hosted a webinar to launch the OECD's new report titled "Towards Green Growth? Tracking Progress". Featuring Carlo Carraro, Catherine L. Mann, Nathalie Girouard and Kevin Urama; this webinar will explore the advances made since the launch of the OECD's green growth strategy in 2011.

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