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Richard Clothier

Publications and source records attributed to Richard Clothier.

6 recordsLinked to original sources
PubMed2006

The FRAME alternatives laboratory database. 1. In vitro basal cytotoxicity determined by the Kenacid blue total protein assay.

A database of over 280 chemicals has been compiled by using a mouse 3T3-L1 fibroblast-like cell line in exponential growth, exposed to chemicals for 72 hours in a 96-well tissue culture plate format, and determining cell number via the Kenacid blue (KB) assay for total protein. Ranking the chemicals according to their basal cytotoxicity, expressed as the concentration (mM) that inhibits increase in total cellular protein over 72 hours by 50% (the ID50 value) shows a wide range of ID50 values, from 0.00003 mM to 10,096 mM. This information includes the results for MEIC chemicals 1-50, and we have now added basal cytotoxicity data for 23 of the next 25 MEIC chemicals. When the neutral red uptake (NRU) assay was performed with the same cell cultures, before the KB assay, very similar indications of basal cytotoxicity were obtained. Comparisons between the results with 3T3-L1 cells and with a human fibroblast-like cell line, BCL-D1 showed a significant difference in order of magnitude of the ID50 value for only 5 of 52 chemicals. However, there was a difference in ID50 value of more than one order of magnitude for 8 of 24 chemicals tested with an undifferentiated teratocarcinoma cell line, F9.

3T3 Cells↗
PubMed2004

Assessment of the potential irritation and photoirritation of novel amino acid-based surfactants by in vitro methods as alternative to the animal tests.

The ultraviolet-A radiation damage effects on skin and eyes will be increased by phototoxic compounds which could be present in pharmaceutical or cosmetic formulations. Great efforts have been made in the last years to find surfactants to replace those with phototoxic potential in commercial use. Series of different in vitro models for phototoxicity, included to validated neutral red uptake (NRU) 3T3 phototoxicity assay are useful screening tools. The phototoxic effects of a novel family of glycerol amino acid-based surfactant compounds were examined via these assays. Human red blood cells and two immortalised cell lines, murine fibroblast cell line 3T3, and one human keratinocyte cell line, HaCaT, were the in vitro models employed to predict potential photoirritation. The phototoxic end-points assessed were hemolysis (human red blood cell test) and resazurin transformation to resorufin and NRU in cell culture methods. The results suggest that no phototoxic effects by any new amino acid derived-surfactants, could be identified.

Amino Acids↗
PubMed2002

ECVAM's collaborations with academia.

The encouragement of ECVAM's connections with academia through direct collaboration and co-sponsored studentships has resulted in the successful achievement of higher degree qualifications for the young participants, and the development and promotion of alternative methods. So far, 26 students have been registered for higher degrees, of which 13 have been awarded so far, and 16 university departments in nine European countries have been directly involved. When other collaborations are included, the number of ECVAM's interactions with academic institutions rises to 33 departments in eleven countries, including the USA. In addition, through contracts awarded to academic institutions and other forms of collaboration, the prevalidation and validation of alternative methods have been progressed.

Animal Testing Alternatives↗
PubMedDate not supplied

The prediction of human skin responses by using the combined in vitro fluorescein leakage/Alamar Blue (resazurin) assay.

A range of cosmetics formulations with human patch-test data were supplied in a coded form, for the examination of the use of a combined in vitro permeability barrier assay and cell viability assay to generate, and then test, a prediction model for assessing potential human skin patch-test results. The target cells employed were of the Madin Darby canine kidney cell line, which establish tight junctions and adherens junctions able to restrict the permeability of sodium fluorescein across the barrier of the confluent cell layer. The prediction model for interpretation of the in vitro assay results included initial effects and the recovery profile over 72 hours. A set of the hand-wash, surfactant-based formulations were tested to generate the prediction model, and then six others were evaluated. The model system was then also evaluated with powder laundry detergents and hand moisturisers: their effects were predicted by the in vitro test system. The model was under-predictive for two of the ten hand-wash products. It was over-predictive for the moisturisers, (two out of six) and eight out of ten laundry powders. However, the in vivo human patch test data were variable, and 19 of the 26 predictions were correct or within 0.5 on the 0-4.0 scale used for the in vivo scores, i.e. within the same variable range reported for the repeat-test hand-wash in vivo data.

Animal Testing Alternatives↗