Richard Clothier: An Appreciation

2007 ◽  
Vol 35 (5) ◽  
pp. 531-537
Author(s):  
Michael Balls
Keyword(s):  
Toxicity Testing ◽  
Research Programme ◽  
In Vitro Cytotoxicity ◽  
Alternative Methods ◽  
Comparative Immunology ◽  
East Anglia ◽  
Cell Functions ◽  
Reed College ◽  
The University

The career of Richard Clothier is reviewed in the light of his long-standing collaboration with Michael Balls and Laurens Ruben at the University of East Anglia (UEA), the University of Nottingham, and Reed College, Portland, Oregon, USA. It began with work at UEA on the aetiology of the lymphosarcoma of Xenopus laevis, followed by studies on the effects of exposure to N-nitroso- N-methylurea on T-cell functions, which led to many contributions to comparative immunology. This was followed by the establishment of the FRAME Research Programme, which led to participation in extensive studies on the development of in vitro cytotoxicity tests and their application in acute and topical toxicity testing. A FRAME Trustee since 1983, Richard Clothier was a co-founder, and subsequently Director, of the FRAME Alternatives Laboratory in the University of Nottingham Medical School, where he led successful collaborations with a number of industrial partners and, in particular, with the European Centre for the Validation of Alternative Methods (ECVAM).

Analogy Models for Prediction of Human Toxicity

1990 ◽  
Vol 18 (1_part_1) ◽  
pp. 103-116
Author(s):  
Sven Hellberg ◽  
Lennart Eriksson ◽  
Jörgen Jonsson ◽  
Fredrik Lindgren ◽  
Michael Sjöström ◽  
...  
Keyword(s):  
Human Subjects ◽  
Toxicity Testing ◽  
In Vitro Cytotoxicity ◽  
Alternative Methods ◽  
Laboratory Animals ◽  
In Vitro Tests ◽  
Human Toxicity ◽  
Efficient Data ◽  
Basal Cytotoxicity

Estimating the toxicity to humans of chemicals by testing on human subjects is not considered to be ethically acceptable, and toxicity testing on laboratory animals is also questionable. Therefore, there is a need for alternative methods that will give estimates of various aspects of human toxicity. Batteries of in vitro tests, together with physicochemical and toxicokinetic data, analysed by efficient data analytical methods, may enable analogy models to be constructed that can predict human toxicity. It may be possible to model non-specific toxicity relating to lipophilicity, or basal cytotoxicity, for a series of diverse compounds with large variation in chemical structure and physicochemical properties. However, local models for a series of similar compounds are generally expected to be more accurate, as well as being capable of modelling more-specific interactions. Analogy models for the prediction of human toxicity are discussed and exemplified with physicochemical and cytotoxicity data from the first ten chemicals in the multicenter evaluation of in vitro cytotoxicity (MEIC) project.

The Galileo Data Bank on Toxicity Testing with In Vitro Alternative Methods. I. General Structure

1994 ◽  
Vol 22 (1) ◽  
pp. 20-30
Author(s):  
Nicola Loprieno ◽  
Guido Boncristiani ◽  
Elena Bosco ◽  
Maria Nieri ◽  
Gregorio Loprieno
Keyword(s):  
General Structure ◽  
Toxicity Testing ◽  
Data Bank ◽  
Alternative Methods ◽  
Scientific Instrument ◽  
Genetic Toxicology ◽  
Evaluation Of Data ◽  
The University ◽  
Methods Of Treatment

Toxicity testing of chemicals by means of in vitro alternative methods to the use of animals has been extensively developed, as documented by a variety of studies. The interpretation of results and the comparative evaluation of data derived from various cell toxicity studies require organisation by a computerised data system, capable of handling the large number of variables included in different assays, such as cell lines, methods of treatment with the chemical, methods used to evaluate the biological effect, endpoints considered, etc. The Galileo Data Bank has been developed by the Laboratory of Genetic Toxicology at the University of Pisa, as a scientific instrument to be used in the analysis and organisation of results obtained in the toxicity testing of chemicals by means of in vitro alternative methods.

The Development and Evaluation of In Vitro Tests by the FRAME Alternatives Laboratory

1995 ◽  
Vol 23 (1) ◽  
pp. 75-90
Author(s):  
Richard H. Clothier ◽  
Karen A. Atkinson ◽  
Michael J. Garle ◽  
Rachel K. Ward ◽  
Angela Willshaw
Keyword(s):  
Research Programme ◽  
Neutral Red ◽  
In Vitro Cytotoxicity ◽  
In Vitro Tests ◽  
Dermal Toxicity ◽  
Mechanisms Of Toxicity ◽  
The Us ◽  
Detergent Association ◽  
Assay Methods

This review outlines the work which has been conducted in the FRAME Alternatives Laboratory during the first ten years of the FRAME Research Programme. A number of in vitro tests, including the kenacid blue, neutral red release and fluorescein leakage assay methods, have been evaluated and have subsequently been included in validation schemes organised by the US Soap and Detergent Association, the US Cosmetic, Toiletry and Fragrance Association, the European Commission and the European Cosmetic, Toiletry and Perfumery Association, as well as in the Scandinavian multicentre evaluation of in vitro cytotoxicity testing scheme. More recently, research has been undertaken in the areas of phototoxicity, immunotoxicity, dermal toxicity and intercellular communication, in addition to investigations into fundamental mechanisms of toxicity.

Integrated Decision-tree Testing Strategies for Environmental Toxicity with Respect to the Requirements of the EU REACH Legislation

2008 ◽  
Vol 36 (1_suppl) ◽  
pp. 29-42 ◽  
Author(s):  
Christina Grindon ◽  
Robert Combes ◽  
Mark T.D. Cronin ◽  
David W. Roberts ◽  
John F. Garrod
Keyword(s):  
Risk Assessment ◽  
Decision Tree ◽  
Aquatic Toxicity ◽  
Toxicity Testing ◽  
Threshold Concentration ◽  
Alternative Methods ◽  
The European Union ◽  
Animal Testing ◽  
Testing Strategies

Liverpool John Moores University and FRAME recently conducted a research project sponsored by Defra on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for safety testing and risk assessment of chemicals. The project covered all the main toxicity endpoints associated with the REACH system. This paper focuses on the prospects for using alternative methods (both in vitro and in silico) for environmental (aquatic) toxicity testing. The manuscript reviews tests based on fish cells and cell lines, fish embryos, lower organisms, and the many expert systems and QSARs for aquatic toxicity testing. Ways in which reduction and refinement measures can be used are also discussed, including the Upper Threshold Concentration — Step Down (UTC) approach, which has recently been retrospectively validated by ECVAM and subsequently endorsed by the ECVAM Scientific Advisory Committee (ESAC). It is hoped that the application of this approach could reduce the number of fish used in acute toxicity studies by around 65–70%. Decision-tree style integrated testing strategies are also proposed for acute aquatic toxicity and chronic toxicity (including bioaccumulation), followed by a number of recommendations for the future facilitation of aquatic toxicity testing with respect to environmental risk assessment.

The Smith Synthesis of ( + )-Lyconadin A

2011 ◽  
Author(s):  
Douglass Taber
Keyword(s):  
Total Synthesis ◽  
Aldol Condensation ◽  
Primary Alcohol ◽  
Selective Reduction ◽  
Axial Direction ◽  
In Vitro Cytotoxicity ◽  
University Of Pennsylvania ◽  
Enantiomerically Pure ◽  
The University

The pentacyclic alkaloid ( + )-lyconadin A 3, isolated from the club moss Lycopodium complanatum, showed modest in vitro cytotoxicity. A key step in the first reported (J. Am. Chem. Soc. 2007, 129, 4148) total synthesis of 3, by Amos B. Smith III of the University of Pennsylvania, was the cyclization of 1 to 2. The pentacyclic alkaloid (+)-lyconadin A 3, isolated from the club moss Lycopodium complanatum, showed modest in vitro cytotoxicity. A key step in the first reported (J. Am. Chem. Soc. 2007, 129, 4148) total synthesis of 3, by Amos B. Smith III of the University of Pennsylvania, was the cyclization of 1 to 2. The pentacyclic skeleton of 3 was constructed around a central organizing piperidine ring 9. This was prepared from the known (and commercial) enantiomerically-pure lactone 4. The akylated stereogenic center of 9 was assembled by diastereoselective hydroxy methylation of the acyl oxazolidinone 5 with s-trioxane, followed by protection. Reduction of the imide to the alcohol led to the mesylate 7, which on reduction of the azide spontaneously cyclized to give, after protection, the piperidine 8. Selective desilylation of the primary alcohol then enabled the preparation of 9. The plan was to assemble the first carbocyclic ring of 3 by intramolecular aldol condensation of the keto aldehyde 15. The enantiomerically-pure secondary methyl substituent of 15 derived from the commercial monoester 10. Activation as the acid fluoride followed by selective reduction led to the volatile lactone 11. Opening of the lactone with H3CONHCH3HCl gave, after protection, the Weinreb amide 12. Alkylation of the derived hydrazone 13, selectively on the methyl group, led, after deprotection, to 15. The intramolecular aldol condensation of 15 did deliver the unstable cyclohexenone 1. Under the acidic conditions of the aldol condensation, the enol derived from the piperidone added in a Michael sense, from the axial direction on the newly-formed ring, to give the trans-fused bicyclic diketone 2.

scholarly journals Alternative methods in toxicity testing: the current approach

2014 ◽  
Vol 50 (1) ◽  
pp. 55-62 ◽  
Author(s):  
Gabrielle Luck de Araújo ◽  
Maria Augusta Amaral Campos ◽  
Maria Anete Santana Valente ◽  
Sarah Cristina Teixeira Silva ◽  
Flávia Dayrell França ◽  
...  
Keyword(s):  
21St Century ◽  
Toxicity Testing ◽  
Current Approach ◽  
Alternative Methods ◽  
New Paradigm ◽  
Community Regulation ◽  
Complex Process ◽  
New Methodologies ◽  
New Vision

Alternative methods are being developed to reduce, refine, and replace (3Rs) animals used in experiments, aimed at protecting animal welfare. The present study reports alternative tests which are based on the principles of the 3Rs and the efforts made to validate these tests. In Europe, several methodologies have already been implemented, such as tests of irritability, cell viability, and phototoxicity as well as in vitro mathematical models together with the use of in silico tools. This is a complex process that spans from development to regulatory approval and subsequent adoption by various official entities. Within this regulatory framework is REACH, the European Community Regulation for chemicals and their safe use. In Brazil, the BraCVAM (Brazilian Center for the Validation of Alternative Methods) was recently established to validate alternative methods and stimulate incorporation of new methodologies. A new vision of toxicology is emerging for the 21st century (Tox-21), and the subsequent changes are shaping a new paradigm.

Validation of In Vitro Cytotoxicity Tests — Past and Present Strategies

1991 ◽  
Vol 19 (2) ◽  
pp. 226-233
Author(s):  
Björn Ekwall ◽  
Inger Bondesson ◽  
Sven Hellberg ◽  
Johan Högberg ◽  
Lennart Romert ◽  
...  
Keyword(s):  
Large Scale ◽  
Toxicity Testing ◽  
Short Review ◽  
Animal Experimentation ◽  
In Vitro Cytotoxicity ◽  
In Vitro Methods ◽  
General Acceptance

In recent years, conventional toxicity testing in animals has been reinforced by in vitro methods. As a result, toxicity testing in some sectors has become more effective and at the same time more ethical. This trend is probably only at its beginning, as many of the newly-developed methods have not yet won general acceptance as a basis for the large-scale replacement and reduction of animal experimentation. What limits the wider use of these methods is validation, i.e. the evaluation of their reliability and relevance. The present paper is a short review of the validation efforts made hitherto, including projects being planned and under discussion. Our own MEIC approach is compared with other strategies. Finally, our opinion on the effectiveness of one large consensus project relative to several different smaller validation programmes is expressed — we advocate the latter strategy, because it will save time and reduce costs.

Integrated Decision-tree Testing Strategies for Developmental and Reproductive Toxicity with Respect to the Requirements of the EU REACH Legislation

2008 ◽  
Vol 36 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Christina Grindon ◽  
Robert Combes ◽  
Mark T.D. Cronin ◽  
David W. Roberts ◽  
John F. Garrod
Keyword(s):  
Risk Assessment ◽  
Decision Tree ◽  
Endocrine Disruption ◽  
Reproductive Toxicity ◽  
Toxicity Testing ◽  
Alternative Methods ◽  
The European Union ◽  
Animal Testing ◽  
Testing Strategies

Liverpool John Moores University and FRAME conducted a research project, sponsored by Defra, 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 paper focuses on the prospects for the use of alternative methods (both in vitro and in silico) in developmental and reproductive toxicity testing. It considers many tests based on primary cells and cell lines, and the available expert systems and QSARs for developmental and reproductive toxicity, and also covers tests for endocrine disruption. Ways in which reduction and refinement measures can be used are also discussed, particularly the use of an enhanced one-generation reproductive study, which could potentially replace the two-generation study, and therefore considerably reduce the number of animals required in reproductive toxicity. Decision-tree style integrated testing strategies are also proposed for developmental and reproductive toxicity and for endocrine disruption, followed by a number of recommendations for the future facilitation of developmental and reproductive toxicity testing, with respect to human risk assessment.

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