Publications by authors named "Horst Spielmann"

86 Publications

Evaluation of in vitro embryotoxicity tests for Chinese herbal medicines.

Reprod Toxicol 2019 10 20;89:45-53. Epub 2019 Jun 20.

College of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou, China; Department of Obstetrics & Gynaecology, The Chinese University of Hong Kong, Shatin, Hong Kong; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong; Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong. Electronic address:

Chinese herbal medicines (CHMs) have been widely used during pregnancy, but feto-embryo safety tests are lacking. Here we evaluated in vitro embryotoxicity tests (IVTs) as alternative methods in assessing developmental toxicity of CHMs. Ten CHMs were selected and classified as strongly, weakly and non-embryotoxic. Three well validated IVTs and prediction models (PMs), including embryonic stem cell test (EST), micromass (MM) and whole embryo culture (WEC), were compared. All strongly embryotoxic CHMs were predicted by MM and WEC PM2. While all weakly embryotoxic CHMs were predicted by MM and WEC PM1. All non-embryotoxic CHMs were classified by EST, MM, but over-classified as weakly embryotoxic by WEC PM1. Overall predictivity, precision and accuracy of WEC determined by PM2 were better than EST and MM tests. Compared with validated chemicals, performance of IVTs for CHMs was comparable. So IVTs are adequate to identify and exclude embryotoxic potential of CHMs in this training set.
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http://dx.doi.org/10.1016/j.reprotox.2019.06.001DOI Listing
October 2019

New techniques for producing transgenic animals - a mixed blessing from both the scientific and animal welfare perspectives.

Altern Lab Anim 2014 May;42(2):93-4

Institute of Pharmacy Freie Universität Berlin, Berlin, Germany.

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http://dx.doi.org/10.1177/026119291404200201DOI Listing
May 2014

A European perspective on alternatives to animal testing for environmental hazard identification and risk assessment.

Regul Toxicol Pharmacol 2013 Dec 23;67(3):506-30. Epub 2013 Oct 23.

UFZ - Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, 04318 Leipzig, Germany. Electronic address:

Tests with vertebrates are an integral part of environmental hazard identification and risk assessment of chemicals, plant protection products, pharmaceuticals, biocides, feed additives and effluents. These tests raise ethical and economic concerns and are considered as inappropriate for assessing all of the substances and effluents that require regulatory testing. Hence, there is a strong demand for replacement, reduction and refinement strategies and methods. However, until now alternative approaches have only rarely been used in regulatory settings. This review provides an overview on current regulations of chemicals and the requirements for animal tests in environmental hazard and risk assessment. It aims to highlight the potential areas for alternative approaches in environmental hazard identification and risk assessment. Perspectives and limitations of alternative approaches to animal tests using vertebrates in environmental toxicology, i.e. mainly fish and amphibians, are discussed. Free access to existing (proprietary) animal test data, availability of validated alternative methods and a practical implementation of conceptual approaches such as the Adverse Outcome Pathways and Integrated Testing Strategies were identified as major requirements towards the successful development and implementation of alternative approaches. Although this article focusses on European regulations, its considerations and conclusions are of global relevance.
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http://dx.doi.org/10.1016/j.yrtph.2013.10.003DOI Listing
December 2013

Reconsidering pluripotency tests: do we still need teratoma assays?

Stem Cell Res 2013 Jul 26;11(1):552-62. Epub 2013 Mar 26.

SET Foundation, Frankfurt am Main, Germany.

The induction of teratoma in mice by the transplantation of stem cells into extra-uterine sites has been used as a read-out for cellular pluripotency since the initial description of this phenomenon in 1954. Since then, the teratoma assay has remained the assay of choice to demonstrate pluripotency, gaining prominence during the recent hype surrounding human stem cell research. However, the scientific significance of the teratoma assay has been debated due to the fact that transplanted cells are exposed to a non-physiological environment. Since many mice are used for a result that is heavily questioned, it is time to reconsider the teratoma assay from an ethical point of view. Candidate alternatives to the teratoma assay comprise the directed differentiation of pluripotent stem cells into organotypic cells, differentiation of cells in embryoid bodies, the analysis of pluripotency-associated biomarkers with high correlation to the teratoma forming potential of stem cells, predictive epigenetic footprints, or a combination of these technologies. Each of these assays is capable of addressing one or more aspects of pluripotency, however it is essential that these assays are validated to provide an accepted robust, reproducible alternative. In particular, the rapidly expanding number of human induced pluripotent stem cell lines, requires the development of simple, affordable standardized in vitro and in silico assays to reduce the number of animal experiments performed.
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http://dx.doi.org/10.1016/j.scr.2013.03.001DOI Listing
July 2013

Assaying embryotoxicity in the test tube: current limitations of the embryonic stem cell test (EST) challenging its applicability domain.

Crit Rev Toxicol 2012 May;42(5):443-64

German Federal Institute for Risk Assessment (BfR), ZEBET - Alternative Methods to Animal Experiments, Berlin, Germany.

Testing for embryotoxicity in vitro is an attractive alternative to animal experimentation. The embryonic stem cell test (EST) is such a method, and it has been formally validated by the European Centre for the Validation of Alternative Methods. A number of recent studies have underscored the potential of this method. However, the EST performed well below the 78% accuracy expected from the validation study using a new set of chemicals and pharmaceutical compounds, and also of toxicity criteria, tested to enlarge the database of the validated EST as part of the Work Package III of the ReProTect Project funded within the 6th Framework Programme of the European Union. To assess the performance and applicability domain of the EST we present a detailed review of the substances and their effects in the EST being nitrofen, ochratoxin A, D-penicillamine, methylazoxymethanol, lovastatin, papaverine, warfarin, β-aminopropionitrile, dinoseb, furosemide, doxylamine, pravastatin, and metoclopramide. By delineation of the molecular mechanisms of the substances we identify six categories of reasons for misclassifications. Some of these limitations might also affect other in vitro methods assessing embryotoxicity. Substances that fall into these categories need to be included in future validation sets and in validation guidelines for embryotoxicity testing. Most importantly, we suggest conceivable improvements and additions to the EST which will resolve most of the limitations.
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http://dx.doi.org/10.3109/10408444.2012.674483DOI Listing
May 2012

A critical evaluation of the 2011 ECHA reports on compliance with the REACH and CLP regulations and on the use of alternatives to testing on animals for compliance with the REACH regulation.

Altern Lab Anim 2011 Oct;39(5):481-93

Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany.

On 30 June 2011, the European Chemicals Agency published two reports, one on the functioning of the REACH system, the other on the use of alternatives to animal testing in compliance with that system. The data presented are based on information gained during the first registration period under the REACH system, which included high production volume chemicals and substances of very high concern, which have the most extensive information requirements. A total of 25,460 registration dossiers were received, covering 3,400 existing, so-called 'phase-in', substances, and 900 new, so-called 'non-phase-in', substances. Data sharing and the joint submission of data are reported to have worked successfully. In the registration dossiers for these substances, results from new animal tests were included for less than 1% of all the endpoints; testing proposals (required for 'higher-tier' information requirements) were submitted for 711 in vivo tests involving vertebrate animals. The registrants mainly used old, existing experimental data, or options for the adaptation (waiving) of information requirements, before collecting new information. For predicting substance toxicity, 'read-across' was the second most-used approach, followed by 'weight-of-evidence'. In vitro toxicity tests played a minor role, and were only used when the respective test methods had gained the status of regulatory acceptance. All in all, a successful start to the REACH programme was reported, particularly since, in contrast to most predictions, it did not contribute to a significant increase in toxicity testing in animals.
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http://dx.doi.org/10.1177/026119291103900509DOI Listing
October 2011

The validated embryonic stem cell test to predict embryotoxicity in vitro.

Nat Protoc 2011 Jun 16;6(7):961-78. Epub 2011 Jun 16.

Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments (ZEBET), Berlin, Germany.

In the embryonic stem cell test (EST), differentiation of mouse embryonic stem cells (mESCs) is used as a model to assess embryotoxicity in vitro. The test was successfully validated by the European Center for the Validation of Alternative Methods (ECVAM) and models fundamental mechanisms in embryotoxicity, such as cytotoxicity and differentiation. In addition, differences in sensitivity between differentiated (adult) and embryonic cells are also taken into consideration. To predict the embryotoxic potential of a test substance, three endpoints are assessed: the inhibition of differentiation into beating cardiomyocytes, the cytotoxic effects on stem cells and the cytotoxic effects on 3T3 fibroblasts. A special feature of the EST is that it is solely based on permanent cell lines so that primary embryonic cells and tissues from pregnant animals are not needed. In this protocol, we describe the ECVAM-validated method, in which the morphological assessment of contracting cardiomyocytes is used as an endpoint for differentiation, and the molecular-based FACS-EST method, in which highly predictive protein markers specific for developing heart tissue were selected. With these methods, the embryotoxic potency of a compound can be assessed in vitro within 10 or 7 d, respectively.
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http://dx.doi.org/10.1038/nprot.2011.348DOI Listing
June 2011

Defined culture medium for stem cell differentiation: applicability of serum-free conditions in the mouse embryonic stem cell test.

Toxicol In Vitro 2011 Jun 3;25(4):914-21. Epub 2011 Mar 3.

German Federal Institute for Risk Assessment (BfR), Centre for Alternative Methods to Animal Experiments-ZEBET, 12277 Berlin, Germany.

The embryonic stem cell test (EST) is a validated method to assess the developmental toxicity potency of chemicals. It was developed to reduce animal use and allow faster testing for hazard assessment. The cells used in this method are maintained and differentiated in media containing foetal calf serum. This animal product is of considerable variation in quality, and individual batches require extensive testing for their applicability in the EST. Moreover, its production involves a large number of foetuses and possible animal suffering. We demonstrate the serum-free medium and feeder cell-free maintenance of the mouse embryonic stem cell line D3 and investigate the use of specific growth factors for induction of cardiac differentiation. Using a combination of bone morphogenetic protein-2, bone morphogenetic protein-4, activin A and ascorbic acid, embryoid bodies efficiently differentiated into contracting myocardium. Additionally, examining levels of intracellular marker proteins by flow cytometry not only confirmed differentiation into cardiomyocytes, but demonstrated significant differentiation into neuronal cells in the same time frame. Thus, this approach might allow for simultaneous detection of developmental effects on both early mesodermal and neuroectodermal differentiation. The serum-free conditions for maintenance and differentiation of D3 cells described here enhance the transferability and standardisation and hence the performance of the EST.
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http://dx.doi.org/10.1016/j.tiv.2011.02.013DOI Listing
June 2011

The embryonic stem cell test as tool to assess structure-dependent teratogenicity: the case of valproic acid.

Toxicol Sci 2011 Apr 11;120(2):360-70. Epub 2011 Jan 11.

German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments-ZEBET, 12277 Berlin, Germany.

Teratogenicity can be predicted in vitro using the embryonic stem cell test (EST). The EST, which is based on the morphometric measurement of cardiomyocyte differentiation and cytotoxicity parameters, represents a scientifically validated method for the detection and classification of chemicals according to their teratogenic potency. Furthermore, an abbreviated protocol applying flow cytometry of intracellular marker proteins to determine differentiation into the cardiomyocyte lineage is available. Although valproic acid (VPA) is in worldwide clinical use as antiepileptic drug, it exhibits two severe side effects, i.e., teratogenicity and hepatotoxicity. These limitations have led to extensive research into derivatives of VPA. Here we chose VPA as model compound to test the applicability domain and to further evaluate the reliability of the EST. To this end, we study six closely related congeners of VPA and demonstrate that both the standard and the molecular flow cytometry-based EST are well suited to indicate differences in the teratogenic potency among VPA analogs that differ only in chirality or side chain length. Our data show that identical results can be obtained by using the standard EST or a shortened protocol based on flow cytometry of intracellular marker proteins. Both in vitro protocols enable to reliably determine differentiation of murine stem cells toward the cardiomyocyte lineage and to assess its chemical-mediated inhibition.
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http://dx.doi.org/10.1093/toxsci/kfr001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3061479PMC
April 2011

Protein biomarkers for in vitro testing of embryotoxicity.

J Proteome Res 2010 Nov 20;9(11):5727-38. Epub 2010 Oct 20.

ProteoSys AG, Carl-Zeiss.-Str. 51, D-55129 Mainz, Germany.

There are new challenges for hazard and risk assessment in the chemical industry with regard to REACH legislation in Europe and related activities in the U.S. and Japan, which require the development of novel in vitro models for the molecular characterization of drug- or chemical-related effects replacing conventional animal testing. In the frame of a European FP6 project on reproductive toxicology ( www.reprotect.eu ), we prepared protein samples from mouse embryonic stem cells differentiated into contracting cardiomyocytes according to the validated embryonic stem cell test (EST) protocol, which had been exposed to toxic substances selected by an expert committee from different in vivo categories of embryotoxicity. Lysates were used to carry out the following investigations: (i) identify optimal dose range conditions in the EST that are suitable for (ii) performing a differential quantitative proteomic study of underlying molecular pathways, (iii) define classes of substances with similar proteomic response patterns, (iv) relate these classes to the traditional in vivo categories of embryotoxicity with (v) the final goal to identify novel surrogate protein biomarker candidates for embryo toxicity. We found two distinct classes of toxic substances (Dinoseb, Ochratoxin-A, and Nitrofen vs β-aminoproprionitril, Metoclopramide, Doxylamine succinate, and d-penicillamine) with clear pathway-related differences in their proteomic patterns. Most notably, different responses to cluster 1 and cluster 2 substances were observed for Heat shock protein β-1, Ras-GTPase-activating protein SH3-domain binding protein, Ran binding protein 5, and Calreticulin, Dihydropyrimidinase-like 2 (Ulip2 protein). On the other hand, Heat shock protein 8 and Fscn1 protein were down-regulated by all compounds from both clusters.
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http://dx.doi.org/10.1021/pr100514eDOI Listing
November 2010

Unexpected common mechanistic pathways for embryotoxicity of warfarin and lovastatin.

Reprod Toxicol 2010 Aug 20;30(1):121-30. Epub 2010 May 20.

ProteoSys AG, Mainz, Germany.

Novel molecular content for fast in vitro strategies in the context of safety tests concerning developmental toxicity has a potential to substantially reduce animal experiments according to the "3R" concept (Reduce/Refine/Replace). Here we present and discuss data from a differential proteomic profiling of samples generated using embryonic stem cell derived in vitro models treated with a set of model substances. Among substance-dependent proteomic changes, potential surrogate markers were some isoforms of heat shock proteins and a component of the Ras pathway, present in several redundant isoforms due to posttranslational modifications. Both proteins are implicated in cell migration, cell survival, growth and embryonic development. Using the examples of warfarin and lovastatin, two substances with entirely different primary targets, the surrogate marker signature nevertheless indicates a common embryotoxic mode of action. We discuss these findings observed in in vitro toxicity tests, in a context of clinical validation and evidence-based toxicology.
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http://dx.doi.org/10.1016/j.reprotox.2010.05.006DOI Listing
August 2010

Collaboration between ZEBET, FRAME, and ECVAM: FRAME's contribution to establishing the Three Rs in Europe.

Authors:
Horst Spielmann

Altern Lab Anim 2009 Dec;37 Suppl 2:23-7

National Centre for Alternative Methods (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany.

FRAME has more than any other institution contributed to the implementation of the Three Rs concept in Europe. The first step was achieved by establishing the European Research Group on Alternatives to Toxicity Testing (ERGATT), in which individual scientists in several European countries began to collaborate to promote the development and validation of in vitro toxicity tests in order to refine, reduce and replace the use of animals in toxicity testing. The first successful project was the start of the INVITOX in vitro toxicology database, which is today managed by ECVAM. Major milestones were the establishment in 1989 of ZEBET, the first national centre for alternatives, in Germany, and of ECVAM in 1991. In 1990, ERGATT and CAAT organised a workshop in Amden, Switzerland, at which European and US scientists developed the concept of experimental validation of toxicity tests, which today remains the basis for the independent, scientific validation process. ECVAM has applied this validation concept in all of its successful validation studies, which have provided in vitro toxicity tests that have been accepted for regulatory purposes by the EU Commission and by the OECD. By re-launching the ATLA journal in 1983, FRAME provided another powerful scientific tool for promoting the Three Rs in Europe and around the world. The close cooperation of scientists from FRAME, ZEBET and ECVAM has most effectively promoted and established the Three Rs as the basic scientific, ethical and legal concept for refining, reducing and replacing the use of experimental animals.
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http://dx.doi.org/10.1177/026119290903702S20DOI Listing
December 2009

The way forward in reproductive/developmental toxicity testing.

Authors:
Horst Spielmann

Altern Lab Anim 2009 Dec;37(6):641-56

Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, Berlin, Germany.

The use of experimental animals in reproductive toxicity testing is critically reviewed on the occasion of the 50th anniversary of the publication of the Three Rs concept by Russell and Burch, since there is major concern that reproductive toxicity testing will significantly increase due to the requirements of the EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) system. A comparison of the test guidelines for drugs, agrochemicals and industrial chemicals shows that, for historical reasons, significantly different testing strategies are applied. The current status of development and validation of in vitro tests in reproductive toxicology is also critically evaluated. The mouse embryonic stem cell test (mEST) is the most advanced and promising of the in vitro tests. Although it has not yet been accepted for regulatory purposes, its use in preclinical drug development is well established. Moreover, promising molecular endpoints have been established in the mEST, including proteomic and toxicogenomic endpoints. Preliminary results have been obtained with a human EST (hEST). In addition, an overview is given on new in vitro reproductive toxicity tests that are currently being developed in the EU FP6 project, ReProTect, since the ReProTect test battery, which covers the essential steps of female and male fertility, implantation and embryotoxicity, holds promise for use as a screening assay for reproductive toxicity testing according to the EU REACH legislation. However, since validated in vitro methods will not be available in the short term, opportunities for the refinement of the standard in vivo tests are discussed, in order to reduce the numbers of animal used in reproductive toxicity testing. Finally, recommendations for toxicity testing in the 21st century call for the harmonisation of test methods across all areas of regulatory testing as a first step. Since the REACH system testing framework for industrial chemicals is driven by the reproductive safety testing requirements of agrochemicals, a shift is proposed to exposure-driven testing of industrial chemicals. In particular, the implementation of a new 'extended one-generation reproductive toxicity study' (EOGRTS), which includes triggers for additional testing for fertility, developmental neurotoxicity and immunotoxicity, would significantly reduce test animal numbers. It is concluded that in vitro methods hold great promise for reproductive toxicity testing in the 21st century, e.g. the ReProTect in vitro battery and the embryonic stem cell (ESC) technology focusing on molecular endpoints in both the mEST and the hEST.
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http://dx.doi.org/10.1177/026119290903700609DOI Listing
December 2009

A 1-year toxicity study in dogs is no longer a scientifically justifiable core data requirement for the safety assessment of pesticides.

Crit Rev Toxicol 2010 Jan;40(1):1-15

ToxAdvice GmbH, Reinach BL, Switzerland.

A review of publications on pesticides assessing the need for 1-year toxicity studies in dogs was performed. Four key peer-reviewed papers with different approaches investigated the value of a 1-year dog study in addition to a 3-month study. Despite different databases and approaches, each concluded with the recommendation to limit the testing of pesticides in dogs to a duration of 3 months. The combined weight of evidence presented in this review reinforces these independent conclusions. Therefore, the routine inclusion of a 1-year dog study as a mandated regulatory requirement for the safety assessment of pesticides is no longer justifiable and a globally harmonized approach should be taken to match the latest legislation of the European Union and the US EPA.
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http://dx.doi.org/10.3109/10408440903300098DOI Listing
January 2010

A modular one-generation reproduction study as a flexible testing system for regulatory safety assessment.

Reprod Toxicol 2010 Apr 4;29(2):242-5. Epub 2009 Oct 4.

Leubnitzer Weg 3c, 13593 Berlin, Germany.

The European Union's Registration, Evaluation and Authorisation of Chemicals (REACH) legislation mandates testing and evaluation of approximately 30,000 existing substances within a short period of time, beginning with the most widely used "high production volume" (HPV) chemicals. REACH testing requirements for the roughly 3000 HPV chemicals specify three separate tests for reproductive toxicity: two developmental toxicity studies on different animal species (OECD Test Guideline 414) and a two-generation reproduction toxicity study (OECD TG 416). These studies are highly costly in both economic and animal welfare terms. OECD TG 416 is a fertility study intended to evaluate reproductive performance of animals in the P and F1-generations following repeated exposure to a test substance. It can also be used to detect adverse effects on structural and functional development. Thus, it has conventionally been preferred to the one-generation study (OECD TG 415). Recently, the Agricultural Chemical Safety Assessment (ACSA) Technical Committee of the ILSI Health and Environmental Sciences Institute (HESI) proposed that routine two-generation studies could in most cases be replaced with an "enhanced" one-generation study (Reuter et al. [1]). The flexible design proposed by HESI-ACSA allows for the addition of one or more specialised modules, if triggered (e.g. production of a second generation or the investigation of classical developmental toxicity or developmental neuro- or immunotoxicity). Significantly, however, the HESI-ACSA proposal was designed for use in the safety assessment of pesticidal, as opposed to industrial, chemicals. Thus for the purposes of REACH, a streamlined one-generation study that also examines structural development would be the most efficient means of addressing current information requirements for HPV chemicals. This study represents a flexible testing system that can be modified to meet regulatory needs in a variety of sectors.
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http://dx.doi.org/10.1016/j.reprotox.2009.09.006DOI Listing
April 2010

A proposed eye irritation testing strategy to reduce and replace in vivo studies using Bottom-Up and Top-Down approaches.

Toxicol In Vitro 2010 Feb 31;24(1):1-9. Epub 2009 May 31.

The Procter & Gamble Company, Brussels, Belgium.

In spite of over 20 years of effort, no single in vitro assay has been developed and validated as a full regulatory replacement for the Draize Eye Irritation test. However, companies have been using in vitro methods to screen new formulations and in some cases as their primary assessment of eye irritation potential for many years. The present report shows the outcome of an Expert Meeting convened by the European Centre for the Validation of Alternative Methods in February 2005 to identify test strategies for eye irritation. In this workshop test developers/users were requested to nominate methods to be considered as a basis for the identification of such testing strategies. Assays were evaluated and categorized based on their proposed applicability domains (e.g., categories of irritation severity, modes of action, chemical class, physicochemical compatibility). The analyses were based on the data developed from current practice and published studies, the ability to predict depth of injury (within the applicable range of severity), modes of action that could be addressed and compatibility with different physiochemical forms. The difficulty in predicting the middle category of irritancy (e.g. R36, GHS Categories 2A and 2B) was recognized. The testing scheme proposes using a Bottom-Up (begin with using test methods that can accurately identify non-irritants) or Top-Down (begin with using test methods that can accurately identify severe irritants) progression of in vitro tests (based on expected irritancy). Irrespective of the starting point, the approach would identify non-irritants and severe irritants, leaving all others to the (mild/moderate) irritant GHS 2/R36 categories.
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http://dx.doi.org/10.1016/j.tiv.2009.05.019DOI Listing
February 2010

Go3R - semantic Internet search engine for alternative methods to animal testing.

ALTEX 2009 ;26(1):17-31

Scientific Consultancy - Animal Welfare, Neubiberg/Munich, Germany.

Consideration and incorporation of all available scientific information is an important part of the planning of any scientific project. As regards research with sentient animals, EU Directive 86/609/EEC for the protection of laboratory animals requires scientists to consider whether any planned animal experiment can be substituted by other scientifically satisfactory methods not entailing the use of animals or entailing less animals or less animal suffering, before performing the experiment. Thus, collection of relevant information is indispensable in order to meet this legal obligation. However, no standard procedures or services exist to provide convenient access to the information required to reliably determine whether it is possible to replace, reduce or refine a planned animal experiment in accordance with the 3Rs principle. The search engine Go3R, which is available free of charge under http://Go3R.org, runs up to become such a standard service. Go3R is the world-wide first search engine on alternative methods building on new semantic technologies that use an expert-knowledge based ontology to identify relevant documents. Due to Go3R's concept and design, the search engine can be used without lengthy instructions. It enables all those involved in the planning, authorisation and performance of animal experiments to determine the availability of non-animal methodologies in a fast, comprehensive and transparent manner. Thereby, Go3R strives to significantly contribute to the avoidance and replacement of animal experiments.
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http://dx.doi.org/10.14573/altex.2009.1.17DOI Listing
May 2009

Embryonic stem cell test remastered: comparison between the validated EST and the new molecular FACS-EST for assessing developmental toxicity in vitro.

Toxicol Sci 2009 Apr 23;108(2):389-400. Epub 2009 Jan 23.

German Federal Institute for Risk Assessment (BfR), Center for Alternative Methods to Animal Experiments - ZEBET, Berlin, Germany.

The embryonic stem cell test (EST) represents a reliable, scientifically validated in vitro system for the detection and classification of compounds according to their teratogenic potency. However, some serious issues were frequently raised against the widespread implementation and practicability of the EST in its original version. Most importantly, the evaluation of the morphological endpoint of beating cell agglomerates requires extensive experimental experience and is prone to misjudgment. Also, the testing period of 10 days is too long and costly to be attractive for industries interested in high-throughput screening of potential drug candidates. These drawbacks prompted us to work out a new molecular approach based on analysis of the expression of certain marker proteins specific for developing heart tissue. We have previously reported that quantitative flow cytometry of marker proteins (i.e., sarcomeric myosin heavy chain and alpha-actinin) can be performed at day 7 in embryonic stem cells from mice and combined with concurrent cell viability analysis. In the present study, extensive investigations were performed in order to explore the predictive power and validity of the newly established EST, subsequently referred to as molecular fluorescence activated cell sorting (FACS)-EST, by applying and comparing a set of 10 well-known embryotoxicants that encompasses the full range of chemical inherent embryotoxic potencies possible. While the molecular FACS-EST offered the same sensitivity compared to the validated EST protocol, the test duration could be significantly reduced. Due to significant improvements, this new molecular method holds promise as a sensitive, more rapid and reproducible screen highly suited to predict developmental toxicity in vivo from in vitro data.
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http://dx.doi.org/10.1093/toxsci/kfp012DOI Listing
April 2009

Developmental and reproductive toxicity testing: animal studies are not predictive for humans.

Authors:
Horst Spielmann

Altern Lab Anim 2008 Dec;36(6):715-6

Faculty of Biology, Chemistry and Pharmacy, Freie Universität Berlin, 12209 Berlin, Germany.

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http://dx.doi.org/10.1177/026119290803600616DOI Listing
December 2008

Assessment of early acute lung injury in rats exposed to aerosols of consumer products: attempt to disentangle the "Magic Nano" conundrum.

Inhal Toxicol 2008 Nov;20(14):1245-62

Institute of Toxicology, Wuppertal.

In Germany in 2006 a series of rapidly developing and sometimes severe cases of pulmonary health impairment were observed after normal use of the "Magic Nano Glass & Ceramic" spray and "Magic Nano Bath" spray. In contrast, the previously marketed "Magic Nano" pump spray product (handheld trigger device without propellants) was unobtrusive. Analysis of particles discharged from these products did not reveal stable (solid) nano-sized particles. The precipitous increase of pulmonary health impairment in humans caused by "Magic Nano Sprays" triggered a comparative assessment of the acute inhalation toxicity of "Magic Nano Glass & Ceramic" spray, "Magic Nano Bath" spray, and "Magic Nano" pump spray in rats. The first two test specimens were examined as spray-can aerosols using an intermittent generation principle, whereas the undiluted liquid content of the pump spray was continuously aerosolized. Groups of Wistar rats were nose-only exposed for 4 h. However, due to mortality occurring already during exposure following exposure to Glass & Ceramic spray, the exposure duration was reduced to approximately 2 h in some groups. In addition to endpoints called for by contemporary testing guidelines, respiratory tract injury was also probed by respiratory function measurements during exposure supplemented by analyses in bronchoalveolar lavage (BAL) fluid on the first postexposure day, including lung histopathology in rats exposed to Glass & Ceramic spray. The Glass & Ceramic spray caused mortality at 2269 mg/m(3) and above, the pump spray was in the beginning lethal range at 81222 mg/m(3), while the bath spray was tolerated without mortality up to the maximum tested nominal concentrations of 28100 mg/m(3). The time-adjusted 4-h LC(50) of Glass & Ceramic spray was 5098 mg/m(3). The analysis of respiratory patterns revealed changes indicative of both upper and lower respiratory tract sensory irritation. In addition to clinical signs suggestive of marked lung irritation, especially in the rats exposed to the Glass & Ceramic spray, histopathology revealed lung inflammation, hemorrhages, edema, and focal septal thickening. Lung weights and BAL endpoints (lactate dehydrogenase [LDH], protein, gamma-glutamyltransaminase, and neutrophilic granulocytes) were markedly increased. In summary, this comparative study demonstrates that the conventional OECD 403 protocol is suitable to comparatively assess the potential and potency of these types of consumer products in their end-use configuration. Measurements in BAL were most suitable for the identification of acute lung injury. By contrast, lung function measurements during exposure did not demonstrate any conclusive association with lung injury. It does not appear that the particle size per se is a key determinant in the toxicity of "Magic Nano Glass & Ceramic" spray (approximately 100% mortality occurred at a MMAD of approximately 7 microm; GSD approximately 3). This might suggest that more volatile substances or substances contained in the test articles that co-evaporate with solvents or water may be causative for the findings observed. Hence, the findings of this study support the notion that the assessment of the acute inhalation toxicity of complex end-use products is methodologically challenging and cannot be readily anticipated based on compositional or physical (particle size) data. Accordingly, in the absence of predictive and validated in vitro assays, in vivo inhalation testing of potentially toxic commercialized spray products appears to be indispensable for consumer safety. In order to prevent indiscriminant testing of such products in bioassays, the development of standardized in vitro alternatives should be considered with high priority.
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http://dx.doi.org/10.1080/08958370802220634DOI Listing
November 2008

The use of reconstructed human epidermis for skin absorption testing: Results of the validation study.

Altern Lab Anim 2008 May;36(2):161-87

Freie Universität Berlin, Institut für Pharmazie, Berlin, Germany.

A formal validation study was performed, in order to investigate whether the commercially-available reconstructed human epidermis (RHE) models, EPISKIN, EpiDerm and SkinEthic, are suitable for in vitro skin absorption testing. The skin types currently recommended in the OECD Test Guideline 428, namely, ex vivo human epidermis and pig skin, were used as references. Based on the promising outcome of the prevalidation study, the panel of test substances was enlarged to nine substances, covering a wider spectrum of physicochemical properties. The substances were tested under both infinite-dose and finite-dose conditions, in ten laboratories, under strictly controlled conditions. The data were subjected to independent statistical analyses. Intra-laboratory and inter-laboratory variability contributed almost equally to the total variability, which was in the same range as that in preceding studies. In general, permeation of the RHE models exceeded that of human epidermis and pig skin (the SkinEthic RHE was found to be the most permeable), yet the ranking of substance permeation through the three tested RHE models and the pig skin reflected the permeation through human epidermis. In addition, both infinite-dose and finite-dose experiments are feasible with RHE models. The RHE models did not show the expected significantly better reproducibility, as compared to excised skin, despite a tendency toward lower variability of the data. Importantly, however, the permeation data showed a sufficient correlation between all the preparations examined. Thus, the RHE models, EPISKIN, EpiDerm and SkinEthic, are appropriate alternatives to human and pig skin, for the in vitro assessment of the permeation and penetration of substances when applied as aqueous solutions.
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http://dx.doi.org/10.1177/026119290803600207DOI Listing
May 2008

Successful validation of in vitro methods in toxicology by ZEBET, the National Centre for Alternatives in Germany at the BfR (Federal Institute for Risk Assessment).

Exp Toxicol Pathol 2008 Jun 28;60(2-3):225-33. Epub 2008 Apr 28.

ZEBET (National Centre for Documentation and Evaluation of Alternative Methods to Animal Experiments) at the Federal Institute for Risk Assessment (BfR=Bundesinstitut für Risikobewertung), Berlin, Germany.

A short description of the history of the 3Rs concept is given, which was developed as the scientific concept to refine, reduce and replace animal experiments by Russel and Burch more than 40 years ago. In addition, the legal framework in Europe for developing alternatives to animal experiments is given and the current status of in vitro systems in pharmacology and toxicology is described including an update on metabolising systems. The decrease in experimental animal numbers during the past decade in Europe is illustrated by the situation in Germany and the contribution of international harmonisation of test guidelines on reducing animal numbers in regulatory testing is described. A review of the development of the principles of experimental validation is given and the 3T3 NRU in vitro phototoxicity test is used as an example for a successful validation study, which led to the acceptance of the first in vitro toxicity test for regulatory purposes by the OECD. Finally, the currently accepted alternative methods for standardisation and safety testing of drugs, biologicals and medical devices are summarised.
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http://dx.doi.org/10.1016/j.etp.2008.01.012DOI Listing
June 2008

The ECVAM international validation study on in vitro tests for acute skin irritation: report on the validity of the EPISKIN and EpiDerm assays and on the Skin Integrity Function Test.

Altern Lab Anim 2007 Dec;35(6):559-601

National Centre for Alternative Methods (ZEBET), Berlin, Germany.

ECVAM sponsored a formal validation study on three in vitro tests for skin irritation, of which two employ reconstituted human epidermis models (EPISKIN, EpiDerm), and one, the skin integrity function test (SIFT), employs ex vivo mouse skin. The goal of the study was to assess whether the in vitro tests would correctly predict in vivo classifications according to the EU classification scheme, "R38" and "no label" (i.e. non-irritant). 58 chemicals (25 irritants and 33 non-irritants) were tested, having been selected to give broad coverage of physico-chemical properties, and an adequate distribution of irritancy scores derived from in vivo rabbit skin irritation tests. In Phase 1, 20 of these chemicals (9 irritants and 11 non-irritants) were tested with coded identities by a single lead laboratory for each of the methods, to confirm the suitability of the protocol improvements introduced after a prevalidation phase. When cell viability (evaluated by the MTT reduction test) was used as the endpoint, the predictive ability of both EpiDerm and EPISKIN was considered sufficient to justify their progression to Phase 2, while the predictive ability of the SIFT was judged to be inadequate. Since both the reconstituted skin models provided false predictions around the in vivo classification border (a rabbit Draize test score of 2), the release of a cytokine, interleukin-1alpha (IL-1alpha), was also determined. In Phase 2, each human skin model was tested in three laboratories, with 58 chemicals. The main endpoint measured for both EpiDerm and EPISKIN was cell viability. In samples from chemicals which gave MTT assay results above the threshold of 50% viability, IL-1alpha release was also measured, to determine whether the additional endpoint would improve the predictive ability of the tests. For EPISKIN, the sensitivity was 75% and the specificity was 81% (MTT assay only); with the combination of the MTT and IL-1alpha assays, the sensitivity increased to 91%, with a specificity of 79%. For EpiDerm, the sensitivity was 57% and the specificity was 85% (MTT assay only), while the predictive capacity of EpiDerm was not improved by the measurement of IL-1alpha release. Following independent peer review, in April 2007 the ECVAM Scientific Advisory Committee endorsed the scientific validity of the EPISKIN test as a replacement for the rabbit skin irritation method, and of the EpiDerm method for identifying skin irritants as part of a tiered testing strategy. This new alternative approach will probably be the first use of in vitro toxicity testing to replace the Draize rabbit skin irritation test in Europe and internationally, since, in the very near future, new EU and OECD Test Guidelines will be proposed for regulatory acceptance.
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http://dx.doi.org/10.1177/026119290703500614DOI Listing
December 2007

A shift of a fundamental paradigm in toxicology.

Authors:
Horst Spielmann

ALTEX 2008 ;25(2):89, U2

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January 2010

The practical application of three validated in vitro embryotoxicity tests. The report and recommendations of an ECVAM/ZEBET workshop (ECVAM workshop 57).

Altern Lab Anim 2006 Oct;34(5):527-38

National Centre for Documentation and Evaluation of Alternative Methods to Animal Experiments (ZEBET), Federal Institute for Risk Assessment (BfR), Berlin, Germany.

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http://dx.doi.org/10.1177/026119290603400504DOI Listing
October 2006