bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolism and Neurotoxicity: The Significance of Genetically Engineered Cell Lines and New Three-Dimensional Cell Cultures
Authors: Coecke Sandra , Eskes Chantra , Gartion Joanne , van Vliet Erwin , Kinsner Agnieszka , Bogni Alessia , Raimondo Laura , Parissis Nicholaos , Langezaal Ingrid
Published: April 2019

Until now, no methods have been validated for the determination of neurotoxic effects or for the evaluation of metabolism-mediated hazards of chemical substances. The current test guidelines are based on studies in vivo, involving animals exposed to the test substance. In the EU White Paper on a Strategy for a Future Chemicals Policy, which may result in up to 30,000 chemicals being screened for toxicity, the use of non-animal test methods is seen as essential and is encouraged. The aim of the present work was to demonstrate the significance of novel technologies, including the use of genetically engineered cell lines and three-dimensional cell culture techniques for direct application in the regulatory hazard-assessment process, with an emphasis on metabolism-mediated toxicity and neurotoxicity.
Genomics: An In Vitro Toxicology Point of View
Authors: Corvi Raffaella
Published: April 2019

Genomics, and in particular its derived discipline, toxicogenomics, are rapidly developing technologies, which permit studies on the impact of chemicals and drugs on gene expression in particular biological systems. Enormous amounts of data will be provided in the context of mechanistic and predictive toxicology from the use of the DNA microarray approach for the simultaneous analysis of the expression pattern of multiple genes. The high-throughput requirement of these approaches necessitates in vitro cell culture systems. This article will give a short overview of the areas of ECVAM's research in which this technology will initially be applied.
Information: Needs for the Future
Authors: Bottrill Krys
Published: April 2019

The four central questions surrounding the use of information are: where to find it; how to find it; how to present it; and how to maintain information availability and information literacy. It is usually assumed that the main source of information for most scientists is the peer-reviewed journal literature. Traditional journal publishing is beset with a number of problems. Although electronic publishing might possibly solve some of these, it in turn introduces new problems. Further problems arise with respect to secondary sources which, in some cases, are being supplemented by electronic archives of full-text documents. One fundamental question that arises when considering any large collection of documents or of records about documents is whether or not to index them, and how to index them. The pros and cons of free-text searching versus the use of controlled vocabularies are discussed, as is the importance of harmonising the Three Rs-related terminology of existing and proposed thesauri. However, there is a further problem that documents pertinent to the Three Rs are not always indexed from this point of view. Authors need to be made aware that, if the information is not provided in the abstract, there is no easy way to identify and retrieve this document from a database. Small specialised databases on the Three Rs in relation to specific subject areas could provide a further solution, especially if they provided references to conference proceedings and book chapters, which are not usually found in the large bibliographical databases. The provision of training in the use of information resources, and the establishment and maintenance of these resources, require investment of money and professional skills. Finally, the future of Three Rs information depends on a recognition that this in an important topic which deserves more than lip service.
The Contributions of the European Cosmetics Industry to the Development of Alternatives to Animal Testing: Dialogue with ECVAM and Future Challenges
Authors: de Silva Odile
Published: April 2019

COLIPA (the European Federation of the Cosmetics Industry) represents 24 international companies and 2000 small and medium-sized enterprises. Together with ECVAM, COLIPA has been involved in the development and validation of alternative methods since the beginning of the validation efforts. The work of the Steering Committee on Alternatives to Animal Testing (SCAAT) is based on collaboration between companies, but also with academia, trade associations, the Scientific Committee on Cosmetics and Non-Food Products (SCCNFP), European Commission Directorates General, and ECVAM. Some success has been achieved, but some validation efforts have failed. One lesson is that the search for alternatives requires a lot of humility.
Dialogue and Collaboration: A Personal View on Laboratory Animal Welfare Developments in General, and on ECVAM's First Decade in Particular
Authors: Koëter Herman B.W.M.
Published: April 2019

A personal view is presented on progress made during the last 25 years in applying the Three Rs ( reduction, refinement, replacement) to animal testing in regulatory toxicology, with an emphasis on “good moments” (for example, international workshops on the principles and practical application of the validation process and on regulatory acceptance) and “not-so-good moments” (for example, the time taken to accept alternatives to the LD50 test and to accept in vitro tests for skin absorption as OECD Test Guidelines). The importance of dialogue and cooperation between international coordinating centres and scientific activities at the national level is stressed, as exemplified by the work of ECVAM during its first decade.
Directive 86/609/EEC on the Protection of Animals Used for Experimental and Other Scientific Purposes
Authors: Louhimies Susanna
Published: April 2019

Directive 86/609/EEC regulates the use of animals for experimental and other scientific purposes in the EU. The Directive seeks to improve the controls on the use of laboratory animals, and to set minimum standards for housing and care, and for the training of personnel handling these animals and supervising the experiments. It also aims to reduce the numbers of animals used for experiments, by encouraging the development and the validation of alternative methods to replace animals methods. Since the scientific basis of the Directive dates back at least 15 years, the Commission is planning on an in-depth revision of the Directive. The Commission aims to have a first draft proposal ready by the end of 2003.
Heterologous Expression of Mouse Cytochrome P450 2e1 in V79 Cells: Construction and Characterisation of the Cell Line and Comparison with V79 Cell Lines Stably Expressing Rat P450 2E1 and Human P450 2E1
Authors: Bernauer Ulrike , Glatt Hansruedi , Heinrich-Hirsch Barbara , Liu Yungang , Muckel Eva , Vieth Bärbel , Gundert-Remy Ursula
Published: April 2019

A V79 Chinese hamster cell line was constructed for stable expression of mouse cytochrome P450 2e1 (Cyp2e1), as an addition to the existing cell battery consisting of cell lines stably expressing rat CYP2E1 and human CYP2E1 (V79 Cell Battery™). The aim was to establish a cell battery that offers the in vitro possibility of investigating species-specific differences in the toxicity and metabolism of chemicals representing substrates for CYP2E1. The newly established cell line (V79m2E1) effectively expressed Cyp2e1 in the catalytically active form. The expression of catalytically active CYP2E1 in V79m2E1 cells was maintained over several months in culture, as demonstrated by Western Blotting and chlorzoxazone (CLX) 6-hydroxylase activity. The cells exhibited CLX 6-hydroxylase activity with a Km of 27.8μM/l and Vmax of 40pmol/mg protein/minute, compared with a Km of 28.2/28.6μM/l and a Vmax of 130/60pmol/mg protein/minute from V79r2E1/V79h2E1 cells. Furthermore, the CYP2E1-dependent mutagenicity of N-nitrosodimethylamine could be demonstrated in the V79m2E1 cells. Therefore, the new cell battery permits the interspecies comparison of CYP2E1-dependent toxicity and of metabolism of chemicals between humans and the two major rodent species — the rat and the mouse — that are usually used in classical toxicity studies.
New Achievements in Human Cell Toxicology: The 20th Annual Workshop on In Vitro Toxicology
Authors: Kolman Ada
Published: April 2019

The 20th Annual Workshop on In Vitro Toxicology (Oxford, UK, September 22–24, 2002) was convened as part of a European meeting entitled Human Cell Culture 2002. The meeting was arranged by the Scandinavian Society for Cell Toxicology (SSCT), the European Tissue Culture Society and the British Prostate Group. Two sessions, which are summarised in this report, were devoted to in vitro toxicology: Human Cell Toxicology and The SSCT Free Paper Session. Outstanding experts in the field of toxicology outlined contemporary approaches in toxicity testing in their lectures. Short oral presentations demonstrated a variety of in vitro model systems and methodologies, which can be useful for investigating human toxicity, as well as for studies on mechanisms of toxicity.
Use of the PFGE Assay for Studies of DNA Breakage Induced by Toxic Chemicals
Authors: Markova Eva , Clemedson Cecilia , Kolman Ada
Published: April 2019

The relevance of the pulsed field gel electrophoresis (PFGE) assay for the estimation of the DNA damaging effects of chemicals was studied. Four chemicals were randomly chosen from the list of 50 Multicentre Evaluation of In Vitro Cytotoxicity (MEIC) reference chemicals with known human acute systemic toxicity: acetylsalicylic acid, paracetamol, ethylene glycol and sodium chloride. Human fibroblasts (VH-10) were used as a model system. For the estimation of cytotoxic effect, cell monolayers were treated with chemicals for 24 hours. Cloning efficiency (colony-forming ability) at different concentrations of the test chemicals was estimated, and the 50% inhibitory concentration (IC50) was determined. The IC50 values obtained demonstrated a correlation with human lethal blood concentrations. The induction of DNA double-strand breaks, measured by PFGE as the fraction of activity released, was detected after treatment with paracetamol. However, the other three chemicals tested mainly induced DNA degradation.
Evaluation of Peristalsis in Multiple Segments of the Guinea-pig Isolated Small Intestine: Optimisation of Tissue Use by Refined In Vitro Methodology
Authors: Holzer Peter , Shahbazian Anaid , Painsipp Evelin , Heinemann Akos
Published: April 2019

Peristalsis is the aboral movement by which the intestine propels its contents. Since pharmacological research requires an experimental model with which drug-induced modifications of peristalsis can be reliably quantified, we set out to develop and validate an in vitro method for studying peristalsis in multiple gut segments. In our arrangement, up to four 10cm segments isolated from the guinea-pig jejunum and ileum can be set up in parallel and their lumens perfused. Peristalsis was elicited by pressure-evoked wall distension, and the peristalsis-induced changes in the intraluminal pressure were evaluated with software that determined the peristaltic pressure threshold, the frequency, maximal acceleration and amplitude of the peristaltic waves, and the residual baseline pressure. Validation experiments showed that the peristalsis parameters at baseline and after modification by morphine (0.01–10μM) did not differ between segments from the jejunum and ileum, or between segments examined in a consecutive manner. In conclusion, our work succeeded in optimising the use of the guinea-pig jejunum and ileum for multiple recordings of peristalsis in vitro, and in refining the recording and evaluation of peristaltic motility. This system promises to be particularly useful in the pharmacological screening and testing of drugs which modify peristalsis.
A Critical Assessment of the OECD Collaborative Study to Validate the Uterotrophic Assay for the Detection of Oestrogenic and Anti-oestrogenic Chemicals
Authors: Combes Robert D.
Published: April 2019

The design and execution of a recently completed validation study on the rat uterotrophic assay for detecting oestrogens and anti-oestrogens, managed by the OECD, are critically assessed with respect to internationally agreed criteria for the validation of new in vitro and in vivo toxicity test methods. It is concluded that, while the design of the study did not take account of several important criteria for validation, the uterotrophic assay appears to reliably detect the strong and weak oestrogenic substances used in the study, which act via binding to the oestrogen receptor in vivo. However, the reliability of the assay has not been substantiated for detecting anti-oestrogens that act as antagonists, due to the involvement of an insufficient number of experiments and test chemicals. Moreover, the data do not permit an assessment of the accuracy of the prediction of oestrogenicity, and the protocols have not been sufficiently optimised with regard to controlling variables. This problem has been exacerbated by a wish to introduce as much flexibility as possible into the protocols during the formal validation phase of the study, rather than during a separate prevalidation stage. In addition, the choice between surgically treated and/or immature animals, and details of housing and husbandry conditions that are necessary for increasing the sensitivity and efficiency of the assay, need to be clarified. The assay also lacks a well-defined prediction model by which the overall relevance of the data to toxicity, and especially to human hazard, can be assessed, and no performance criteria have been established. The results of this analysis of the study indicate that it would be premature to produce an OECD test guideline for the uterotrophic assay at this time, before some of the above issues have been satisfactorily resolved.
Biostatistical Methods for the Validation of Alternative Methods for In Vitro Toxicity Testing
Authors: Edler Lutz , Ittrich Carina
Published: April 2019

Statistical methods for the validation of toxicological in vitro test assays are developed and applied. Validation is performed either in comparison with in vivo assays or in comparison with other in vitro assays of established validity. Biostatistical methods are presented which are of potential use and benefit for the validation of alternative methods for the risk assessment of chemicals, providing at least an equivalent level of protection through in vitro toxicity testing to that obtained through the use of current in vivo methods. Characteristic indices are developed and determined. Qualitative outcomes are characterised by the rates of false-positive and false-negative predictions, sensitivity and specificity, and predictive values. Quantitative outcomes are characterised by regression coefficients derived from predictive models. The receiver operating characteristics (ROC) technique, applicable when a continuum of cut-off values is considered, is discussed in detail, in relation to its use for statistical modelling and statistical inference. The methods presented are examined for their use for the proof of safety and for toxicity detection and testing. We emphasise that the final validation of toxicity testing is human toxicity, and that the in vivo test itself is only a predictor with an inherent uncertainty. Therefore, the validation of the in vitro test has to account for the vagueness and uncertainty of the “gold standard” in vivo test. We address model selection and model validation, and a four-step scheme is proposed for the conduct of validation studies. Gaps and research needs are formulated to improve the validation of alternative methods for in vitro toxicity testing.
The Role of Control Groups in Mutagenicity Studies: Matching Biological and Statistical Relevance
Authors: Hauschke Dieter , Hothorn Torsten , Schäfer Juliane
Published: April 2019

The statistical test of the conventional hypothesis of “no treatment effect” is commonly used in the evaluation of mutagenicity experiments. Failing to reject the hypothesis often leads to the conclusion in favour of safety. The major drawback of this indirect approach is that what is controlled by a prespecified level α is the probability of erroneously concluding hazard (producer risk). However, the primary concern of safety assessment is the control of the consumer risk, i.e. limiting the probability of erroneously concluding that a product is safe. In order to restrict this risk, safety has to be formulated as the alternative, and hazard, i.e. the opposite, has to be formulated as the hypothesis. The direct safety approach is examined for the case when the corresponding threshold value is expressed either as a fraction of the population mean for the negative control, or as a fraction of the difference between the positive and negative controls.
Dose–Response and Thresholds in Mutagenicity Studies: A Statistical Testing Approach
Authors: Hothorn Ludwig A. , Bretz Frank
Published: April 2019

The analysis of dose–response relationships is an important objective in toxicology, and one in which both modelling and testing approaches are used. One particular question is whether a threshold exists at low doses. The concept of a pragmatic threshold is used, i.e. low doses with biologically unimportant effects are assumed to be threshold doses. “Biologically unimportant” means, in statistical terms, a lower effect than the effect of the negative control, or at least a just-tolerable margin δ higher than the effect of the negative control. Therefore, threshold doses can be tested in terms of a one-sided hypothesis of equivalence. A new approach is proposed, assuming, at the least, that the low dose is a threshold dose, and the highest dose is superior to the negative control. By analogy to the k-fold rule commonly used in mutagenicity studies, tests on ratio-to-control are used. The a priori definition of the threshold margin is inherently needed. A further approach proposes the analysis of dose–response relationships by means of order-restricted inference (the so-called trend test). A modification of a multiple-contrast test is used, in which only those contrasts are included that are sensitive for no effects at low doses. A further modification treats the complicated, but real, problem of simultaneous existence of a threshold, a monotonic increase, and a downturn effect at high dose(s). A parametric procedure is considered, together with an extension for proportions. The important problem of a priori sample size definition is discussed. The approaches are demonstrated by means of examples based on real data.
Ecotoxicological Evaluation of Municipal Sludge
Authors: Srivastava Richa , Tewari Anamika , Chauhan Lalit K.S. , Kumar Dinesh , Gupta Shrawan K.
Published: April 2019

Municipal wastes originating from urban and industrial areas have become a major source of soil, ground and surface water pollution. These undesirable agents in our environment significantly interact with our flora and fauna. The aim of this study was to test samples of municipal sludge (MS) for their ecotoxicological potential by using sensitive bioassays involving a plant, Vicia faba, and the earthworm, Eisenia foetida. A 10% leachate of MS was prepared for the experiments, and V. faba seedlings were exposed to three leachate concentrations (2.5%, 5% and 10%) for 5 days. The findings revealed chromosome aberrations during the metaphase as well as the anaphase of cell division, and inhibition of the mitotic index, which reflects that MS originating from domestic and other human activities may be genotoxic to the living organisms of the ecosystem. Abnormalities in chlorophyll content, plant growth, root length, shoot length and root/shoot length ratio in V. faba clearly indicated the toxicity of the sludge. Behavioural and reproduction studies with E. foetida also provided evidence for the toxic nature of the MS.
Anaesthesia and Post-operative Analgesia following Experimental Surgery in Laboratory Rodents: Are we Making Progress?
Authors: Richardson Claire A. , Flecknell Paul A.
Published: April 2019

Current attitudes to the use of animals in biomedical research require that any pain or distress should be minimised. This can often be achieved by the use of appropriate anaesthetic and analgesic regimens. There, is however, little information on the peri-operative regimens used. A literature review was conducted to estimate how commonly analgesics are administered to laboratory rodents, the most widely used species of laboratory animals, and to assess the anaesthetic regimens employed. Studies describing potentially painful experimental procedures involving rodents were identified from peer-reviewed journals published from 1990 to 1992 and from 2000 to 2002. In papers published between 2000 and 2002, if analgesic administration was not specified, the institutional veterinary surgeons or authors of the papers were contacted by e-mail to obtain additional information on analgesic use. From 1992 to 2002, there was an increase in the reported prevalence of analgesic administration to laboratory rodents from 2.7% to 19.8%. Although the use of analgesics has increased over the past ten years, the overall level of post-operative pain relief for laboratory rodents is still low. Anaesthetic methodology changed markedly between the two time-periods sampled. Notably, there was an increase in the use of isoflurane and of injectable anaesthetic combinations such as ketamine/xylazine, whereas the use of ether and methoxyflurane decreased.
Chicken Egg Yolk Antibodies (IgY-technology): A Review of Progress in Production and Use in Research and Human and Veterinary Medicine
Authors: Schade Rüdiger , Calzado Esteban Gutierrez , Sarmiento Rodolfo , Chacana Pablo Anibal , Porankiewicz-Asplund Joanna , Terzolo Horacio Raul
Published: April 2019

The production of antibodies (Abs) in chickens and the extraction of specific Abs from egg yolk (IgY Abs) are increasingly attracting the interest of the scientific community, as demonstrated by the significant growth of the IgY literature. This review offers detailed and comprehensive information about IgY-technology, including: a) possibilities for hen keeping in accordance with the Three Rs principles; b) new insights into the IgY transfer mechanism from blood to yolk as a biological basis for the technology; c) the comparative characteristics of IgY Abs and IgG Abs; d) the high efficacy of the technique, in view of the extraordinary amount of IgY Ab produced by one hen in one year (between 20g and 40g IgY in total); e) comparisons between the efficacies of IgY Abs and IgG Abs (rabbit, sheep, mouse) in several immunological assays; f) immunisation protocols, as well as the most commonly used IgY-extraction procedures; g) new possibilities for application in human and veterinary medicine, including strategies for the treatment of Helicobacter pylori infection or fatal intestinal diseases in children, particularly in poor countries, for reducing the use of antibiotics, and, in Asia and South America, for producing Abs against snake, spider and scorpion venoms; and h) the use of IgY Abs in various fields of research, also taking into consideration recent developments in South America (particularly Argentina and Cuba) and in Asia.
Reduction Strategies in Animal Research: A Review of Scientific Approaches at the Intra-experimental, Supra-experimental and Extra-experimental Levels
Authors: de Boo Jasmijn , Hendriksen Coenraad
Published: April 2019

When discussing animal use and considering alternatives to animals in biomedical research and testing, the number of animals required gets to the root of the matter on ethics and justification. In this paper, some reduction strategies are reviewed. Many articles and reports on reduction of animal use focus mostly on the experimental level, but other approaches are also possible. Reduction at the intra-experimental level probably offers the greatest scope for reduction, as the design and statistical analysis of individual experiments can often be improved. Supra-experimental reduction aims to reduce the number of animals by a change in the setting in which a series of experiments take place — for example, by improved education and training, reduction of breeding surpluses, critical analysis of test specifications, and re-use of animals. At the extra-experimental level, reduction is a spin-off of other developments, rather than the direct goal. Through improved research or production strategies, aimed at better quality, consistency and safety, reduction in the number of animals used can be substantial. A revised definition of reduction is proposed, which does not include the level of information needed, as in some cases reduction in the number of animals resulting in less information or data, is still acceptable.
Changes in Extracellular Action Potential Detect Kainic Acid and Trimethyltin Toxicity in Hippocampal Slice Preparations Earlier than do MAP2 Density Measurements
Authors: Melani Raffaella , Rebaudo Renata , Noraberg Jens , Zimmer Jens , Balestrino Maurizio
Published: April 2019

In vitro electrophysiological techniques for the assessment of neurotoxicity could have several advantages over other methods in current use, including the ability to detect damage at a very early stage, and could further assist in replacing animal experimentation in vivo. We investigated how an electrophysiological parameter, the extracellularly-recorded compound action potential (“population spike”, PS) could be used as a marker of in vitro neurotoxicity in the case of two well-known toxic compounds, kainic acid (KA) and trimethyltin (TMT). We compared the use of this electrophysiological endpoint with changes in immunoreactivity for microtubule-associated protein 2 (MAP2), a standard histological test for neurotoxicity. We found that both toxic compounds reliably caused disappearance of the PS, and that such disappearance occurred after only 1 hour of exposure to the drug. By contrast, densitometric measurements of MAP2 immunoreactivity were unaffected by both KA and TMT after such a short exposure time. We conclude that, in the case of KA and TMT, the extracellular PS was abolished at a very early time-point, when MAP2 immunoreactivity levels were still comparable to those of the untreated controls. Electrophysiology could be a reliable and early indicator of neurotoxicity, which could improve our ability to test for neurotoxicity in vitro, thus further replacing the need for in vivo experimentation.
An Approach to Determining Applicability Domains for QSAR Group Contribution Models: An Analysis of SRC KOWWIN
Authors: Nikolova-Jeliazkova Nina , Jaworska Joanna
Published: April 2019

QSAR model predictions are most reliable if they come from the model's applicability domain. The Setubal Workshop report provides a conceptual guidance for defining a (Q)SAR applicability domain. However, an operational definition is necessary for applying this guidance in practice. It should also permit the design of an automatic (computerised) procedure for determining a model's applicability domain. This paper attempts to address this need for models that use a large number of descriptors (for example, group contribution-based models). The high dimensionality of these models imposes specific computational restrictions on estimating the interpolation region. The Syracuse Research Corporation KOWWIN model for prediction of the n-octanol/water partition coefficient is analysed as a case study. This is a linear regression model that uses 508 fragment counts and correction factors as descriptors, and is based on the group contribution approach. We conclude that the applicability domain estimation by descriptor ranges, combined with Principal Component rotation as a data pre-processing step, is an acceptable compromise between estimation accuracy and the amount of data in the training set.
The Interpretation and Application of the Three Rs by Animal Ethics Committee Members
Authors: Schuppli Catherine A. , Fraser David
Published: April 2019

The Three Rs form the basis of review of animal-use protocols by Animal Ethics Committees (AECs), but little research has examined how AECs actually interpret and implement the Three Rs. This topic was explored through in-depth, open-ended interviews with 28 members of AECs at four Canadian universities. In describing protocol review, AEC members rarely mentioned the Three Rs, but most reported applying some aspects of the basic concepts. Comments identified several factors that could impede full application of the Three Rs: incomplete understanding of the Three Rs (especially Refinement), trust that researchers implement Replacement and Reduction themselves, belief by some members that granting agency review covers the Three Rs, focus on sample size rather than experimental design to achieve Reduction, focus on harm caused by procedures to the exclusion of housing and husbandry, and lack of consensus on key issues, notably on the nature and moral significance of animal pain and suffering, and on whether AECs should minimise overall harm to animals. The study suggests ways to achieve more consistent application of the Three Rs, by providing AECs with up-to-date information on the Three Rs and with access to statistical expertise, by consensus-building on divisive issues, and by training on the scope and implementation of the Three Rs.
Comparison of an Animal Product Free Medium and Normal Growth Supplement on the Growth and Barrier Integrity of a Human Corneal Epithelial Cell Line
Authors: Wilkinson Peter J. , Clothier Richard H.
Published: April 2019

With the development of defined media for general and specific use with cell cultures, and concern over the use of human cells and over potential prion infections associated with growth factor extracts such as bovine pituitary extract, an animal product-free medium has become available. The basic keratinocyte defined medium can be used with a choice of animal product-containing or animal product-free supplements. Human corneal epithelia cell lines were cultured in the media with these two types of supplement, and compared in terms of their growth rates, their capacity to form tight barriers, and calcium regulation of the location of a junction-associated protein, zonula occludins-1 (ZO-1). The growth rates were not different in the two media, as long as the recommended coating was applied to the culture flask for the animal product-free medium. The barrier function was equally effective for confluent cultures seeded at the same densities. A calcium concentration of 100μM or above resulted in ZO-1 localisation at the cell membrane in either medium. Hence, cultures in the media are comparable, when the coating is employed. Further experiments are being conducted to establish the comparability of responses to chronic treatment with surfactants.
Detection of Electrophysiological Indicators of Neurotoxicity in Human and Rat Brain Slices by a Three-Dimensional Microelectrode Array
Authors: Köhling Rüdiger , Melani Raffaella , Koch Uwe , Speckmann Erwin-Josef , Koudelka-Hep Milena , Thiébaud Pierre , Balestrino Maurizio
Published: April 2019

Electrophysiological techniques for the assessment of in vitro neurotoxicology have several advantages over other currently-used methods (for example, morphological techniques), including the ability to detect damage at a very early stage. Novel recording techniques based on microelectrode arrays are available, and could improve recording power. In this study, we investigated how a three-dimensional microelectrode array detects the electrophysiological endpoints of neurotoxicity. We conclude that electrophysiology sensitively reveals neurotoxic actions, and that three-dimensional microelectrode arrays could be proposed for use in neurotoxicology as recording tools that allow easy and sensitive multisite recording, from both rodent and human brain tissue.
An Evaluation of the In Vitro Cytotoxicities of 50 Chemicals by using an Electrical Current Exclusion Method versus the Neutral Red Uptake and MTT Assays
Authors: Lindl Toni , Lewandowski Birgit , Schreyögg Sonya , Stäudte Andrea
Published: April 2019

According to the 2001 National Institutes of Health guidance document on using in vitro data to estimate in vivo starting doses for acute toxicity, the performance of the electrical current exclusion method (ECE) was studied for its suitability as an in vitro cytotoxicity test. In a comparative study, two established in vitro assays based on the quantification of metabolic processes necessary for cell proliferation or organelle integrity (the MTT/WST-8 [WST-8] assay and the neutral red uptake [NRU] assay), and two cytoplasm membrane integrity assays (the trypan blue exclusion [TB] and ECE methods), were performed. IC50 values were evaluated for 50 chemicals ranging from low to high toxicity, 46 of which are listed in Halle's Registry of Cytotoxicity (RC). A high correlation was found between the IC50 values obtained in this study and the IC50 data published in the RC. The assay sensitivity was highest for the ECE method, and decreased from the WST-8 assay to the NRU assay to the TB assay. The consistent results of the ECE method are based on technical standardisation, high counting rate, and the ability to combine cell viability and cell volume analysis for detection of the first signs of cell necrosis and damage of the cytoplasmic membrane caused by cytotoxic agents.
An Inter-laboratory Study to Evaluate the Effects of Medium Composition on the Differentiation and Barrier Function of Caco-2 Cell Lines
Authors: Zucco Flavia , Batto Anne-Françoise , Bises Giovanna , Chambaz Jean , Chiusolo Arianna , Consalvo Rosa , Cross Heide , Dal Negro Gianni , de Angelis Isabella , Fabre Gérard , Guillou François , Hoffman Sebastian , Laplanche Loïc , Morel Etienne , Pinçon-Raymond Martine , Prieto Pilar , Turco Laura , Ranaldi Giulia , Rousset Monique , Sambuy Yula , Scarino Maria Laura , Torreilles François , Stammati Annalaura
Published: April 2019

Differentiated human intestinal Caco-2 cells are frequently used in toxicology and pharmacology as in vitro models for studies on intestinal barrier functions. Since several discrepancies exist among the different lines and clones of Caco-2 cells, comparison of the results obtained and optimisation of models for use for regulatory purposes are particularly difficult, especially with respect to culture conditions and morphological and biochemical parameters. An inter-laboratory study has been performed on the parental cell line and on three clonal Caco-2 cell lines, with the aim of standardising the culture conditions and identifying the best cell line with respect to parameters relevant to barrier integrity, namely, transepithelial electrical resistance (TEER) and mannitol passage, and of epithelial differentiation (alkaline phosphatase activity). Comparison of the cell lines maintained in traditional serum-supplemented culture medium or in defined medium, containing insulin, transferrin, selenium and lipids, showed that parameter performance was better and more reproducible with the traditional medium. The maintenance of the cell lines for 15 days in culture was found to be sufficient for the development of barrier properties, but not for full epithelial differentiation. Caco-2/TC7 cells performed better than the other three cell lines, both in terms of reproducibility and performance, exhibiting low TEER and mannitol passage, and high alkaline phosphatase activity.
The Relevance of Genetically Altered Mouse Models of Human Disease
Authors: Bhogal Nirmala , Combes Robert
Published: April 2019

The impetus to develop useful models of human disease and toxicity has resulted in a number of large-scale mouse mutagenesis programmes. This, in turn, has stimulated considerable concern regarding the scientific validity and welfare of genetically altered mice, and the large numbers of mice that are required by such programmes. In this paper, the scientific advantages and limitations of genetically altered mice as models of several human diseases are discussed. We conclude that, while the use of some such mouse models has contributed considerably to an understanding of human disease and toxicity, other genetically altered mouse models have limited scientific relevance, and fewer have positively contributed to the development of novel human medicines. Suggestions for improving this unsatisfactory situation are made.
S-Adenosylmethionine Exerts a Protective Effect against Thioacetamide-induced Injury in Primary Cultures of Rat Hepatocytes
Authors: Lotková Halka , Čvervinková Zuzana , Kučera Otto , Roušar Tomáš , Křiváková Pavla
Published: April 2019

S-adenosylmethionine (SAMe) has been shown to protect hepatocytes from toxic injury, both experimentally-induced in animals and in isolated hepatocytes. The mechanisms by which SAMe protects hepatocytes from injury can result from the pathways of SAMe metabolism. Unfortunately, data documenting the protective effect of SAMe against mitochondrial damage from toxic injury are not widely available. Thioacetamide is frequently-used as a model hepatotoxin, which causes in vivo centrilobular necrosis. Even though thioacetamide-induced liver necrosis in rats was alleviated by SAMe, the mechanisms of this protective effect remain to be verified. The aim of our study was to determine the protective mechanisms of SAMe on thioacetamide-induced hepatocyte injury by using primary hepatocyte cultures. The release of lactate dehydrogenase (LDH) from cells incubated with thioacetamide for 24 hours, was lowered by simultaneous treatment with SAMe, in a dose-dependent manner. The inhibitory effect of SAMe on thioacetamide-induced lipid peroxidation paralleled the effect on cytotoxicity. A decrease in the mitochondrial membrane potential, as determined by Rhodamine 123 accumulation, was also prevented. The attenuation by SAMe of thioacetamide-induced glutathione depletion was determined after subsequent incubation periods of 48 and 72 hours. SAMe protects both cytoplasmic and mitochondrial membranes. This effect was more pronounced during the development of thioacetamide-induced hepatocyte injury that was mediated by lipid peroxidation. Continuation of the SAMe treatment then led to a reduction in glutathione depletion, as a potential consequence of an increase in glutathione production, for which SAMe is a precursor.
Molecular Targets and Early Response Biomarkers for the Prediction of Developmental Toxicity In Vitro
Authors: Stigson Michael , Kultima Kim , Jergil Måns , Scholz Birger , Alm Henrik , Gustafson Anne-Lee , Dencker Lennart
Published: April 2019

There is an urgent need for new in vitro methods to predict the potential developmental toxicity of candidate drugs in the early lead identification and optimisation process. This would lead to a reduction in the total number of animals required in full-scale developmental toxicology studies, and would improve the efficiency of drug development. However, suitable in vitro systems permitting robust high-throughput screening for this purpose, for the most part, remain to be designed. An understanding of the mechanisms involved in developmental toxicity may be essential for the validation of in vitro tests. Early response biomarkers — even a single one — could contribute to reducing assay time and facilitating automation. The use of toxicogenomics approaches to study in vitro and in vivo models in parallel may be a powerful tool in defining such mechanisms of action and the molecular targets of toxicity, and also for use in finding possible biomarkers of early response. Using valproic acid as a model substance, the use of DNA microarrays to identify teratogen-responsive genes in cell models is discussed. It is concluded that gene expression in P19 mouse embryocarcinoma cells represents a potentially suitable assay system, which could be readily used in a tiered testing system for developmental toxicity testing.
The Application of Normal, SV40 T-antigen-immortalised and Tumour-derived Oral Keratinocytes, under Serum-free Conditions, to the Study of the Probability of Cancer Progression as a Result of Environmental Exposure to Chemicals
Authors: Ceder Rebecca , Merne Marina , Staab Claudia A. , Nilsson Jan Anders , Höög Jan-Olov , Dressler Dirk , Engelhart Karin , Grafström Roland C.
Published: April 2019

In vitro models are currently not considered to be suitable replacements for animals in experiments to assess the multiple factors that underlie the development of cancer as a result of environmental exposure to chemicals. An evaluation was conducted on the potential use of normal keratinocytes, the SV40 T-antigen-immortalised keratinocyte cell line, SVpgC2a, and the carcinoma cell line, SqCC/Y1, alone and in combination, and under standardised serum-free culture conditions, to study oral cancer progression. In addition, features considered to be central to cancer development as a result of environmental exposure to chemicals, were analysed. Genomic expression, and enzymatic and functional data from the cell lines reflected many aspects of the transition of normal tissue epithelium, via dysplasia, to full malignancy. The composite cell line model develops aberrances in proliferation, terminal differentiation and apoptosis, in a similar manner to oral cancer progression in vivo. Transcript and protein profiling links aberrations in multiple gene ontologies, molecular networks and tumour biomarker genes (some proposed previously, and some new) in oral carcinoma development. Typical specific changes include the loss of tumour-suppressor p53 function and of sensitivity to retinoids. Environmental agents associated with the aetiology of oral cancer differ in their requirements for metabolic activation, and cause toxic effects to cells in both the normal and the transformed states. The results suggest that the model might be useful for studies on the sensitivity of cells to chemicals at different stages of cancer progression, including many aspects of the integrated roles of cytotoxicity and genotoxicity. Overall, the properties of the SVpgC2a and SqCC/Y1 cell lines, relative to normal epithelial cells in monolayer or organotypic culture, support their potential applicability to mechanistic studies on cancer risk factors, including, in particular, the definition of critical toxicity effects and dose–effect relationships.
An Integrated Decision-tree Testing Strategy for Skin Sensitisation with Respect to the Requirements of the EU REACH Legislation
Authors: Grindon Christina , Combes Robert , Cronin Mark T.D. , Roberts David W. , Garrod John F.
Published: April 2019

This report presents some of the results of a joint research project, sponsored by Defra and conducted by FRAME and Liverpool John Moores University, on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for the safety testing and risk assessment of chemicals. The project covered all the main toxicity endpoints associated with the REACH system. This report focuses on the use of alternative (non-animal) methods (both in vitro and in silico) for skin sensitisation testing. The manuscript reviews in vitro tests based on protein-ligand binding, dendritic/Langerhans cells and T-lymphocyte activation, and also the QSAR models and expert systems available for this endpoint. These tests are then incorporated into an integrated, decision-tree testing strategy, which also includes the Local Lymph Node Assay (in its original and new reduced protocols) and the traditional guinea-pig tests (which should only be used as a last resort). The aim of the strategy is to minimise the use of animals in testing for skin sensitisation, while satisfying the scientific and logistical demands of the EU REACH legislation.
An Evaluation of Sterilisation Processes
Authors: Śladowski Dariusz , Grabska-Liberek Iwona , Olkowska-Truchanowicz Joanna , Lipski Kamil , Gut Grzegorz
Published: April 2019

A sterile environment is one of the basic elements of in vitro cell culture. When choosing an appropriate sterilisation method, the possibility that the physical and chemical properties of the sterilised material could be altered by the sterilisation process itself, should be considered. Avoiding any potential problems of toxicity arising as a consequence of the sterilisation process is essential, not only in in vitro cell culture procedures, but especially in the case of the sterilisation of medical devices which come into contact with human tissue (e.g. catheters, surgical tools, and containers used for transplant preparation and storage). As it is not possible to predict the potential effects of every combination of test material and sterilisation process, we have designed a simple test, which can be easily performed to ensure the absence of cytotoxicity. The test involves the culturing of a non-adherent cell line in direct contact with the test material, in micro-wells attached to the surface of the test device. By using this novel test method, three sterilisation procedures were compared for each material. The results indicated that, neither ionising irradiation nor ethylene oxide left toxic residues on the surface of polystyrene; and that, in the case of steel, neither steam sterilisation nor ethylene oxide left toxic residues on the metal. The cold plasma system, which left toxic residues on the surface of both materials, required a post-sterilisation period of 24 hours in the case of steel, and 10 days in the case of polystyrene, in order to eliminate toxic residues prior to their use.
Welfare Implications of Standardised Protocols for Phenotyping and Genotyping Genetically Altered Mice
Authors: Bhogal Nirmala , Scrivens Michelle
Published: April 2019

Phenotype-driven mouse mutagenesis programmes are widely advocated as a means of assigning functions to human genes. These programmes often give rise to a number of animal welfare concerns, not least the large numbers of animals that are used. Here, we consider how the phenotyping screens used in all such programmes can be improved, with specific reference to the standard phenotyping procedures described by the European Mouse Phenotyping Resource of Standardised Screens (EMPReSS). Although we commend the efforts of the Consortium in developing standardised screens for phenotyping, animal welfare should take precedence over technical ease and the cost implications of the research. A number of recommendations are made that could reduce the suffering of the mice used in such studies. These include the use of minimally invasive practices, reduced sample sizes, and combining the assays used in such studies.
Batch Safety Testing of Veterinary Vaccines — Potential Welfare Implications of Injection Volumes
Authors: Cooper Jane
Published: April 2019

This study examines the volumes administered by injection during the batch safety testing of veterinary vaccines according to the methods laid down in European Pharmacopoeia monographs. These are compared with maximum dose volumes recommended in good practice guidelines. The volumes administered during safety tests frequently exceeded recommended maximums, giving rise to concerns that these tests may seriously compromise animal welfare. This was particularly the case for live liquid vaccines and for vaccines recommended for intramuscular injection. The volumes used in testing vaccines for avian species exceeded the recommended maximums by the greatest amount. The administration of test doses should be performed in a way that minimises pain and discomfort. The refinement of tests by dividing large dose volumes and delivering them over multiple sites is discussed, but it is recognised that there are technical limitations, which in some cases may cause difficulties with fulfilling the purpose of the tests. Previously, the relevance of batch safety tests has been widely criticised, due to a lack of evidence that they contribute to the safety of veterinary medicines. By showing that the conduct of target animal safety tests can involve injection volumes that compromise the welfare of the animals involved, this analysis highlights the need for a more critical assessment of the necessity and justification for these tests.