Letter From FrameBy Caren L. Broadhead, Ph.D. FRAME (Fund for the Replacement of Animals in Medical Experiments) is pleased that it has been asked to contribute regularly to the CAAT Newsletter by writing a letter. In our first letter we would like to give an overview of FRAME's aims and current work. FRAME was founded as a Charitable Trust in 1969 by Dorothy Hegarty. FRAME's first premises were situated in Dorothy Hegarty's spare room. FRAME moved to offices in Raynes's Park, London in 1971 and in 1974, the journal of Abstracts of Alternatives to Laboratory Animals (later to become ATLA Abstracts) was launched. FRAME left London in 1981 to take up offices in Nottingham, where strong links were developed with the University of Nottingham. It was at this time that the FRAME trustees established the FRAME Research Programme, with the aim of developing new methods to replace the use of animals in research and testing. A multicentre research programme commenced with the aim of developing cell culture methods for use as a preliminary screen for assessing the acute toxicities of chemicals. The need for a laboratory dedicated to the development and evaluation of in vitro alternative methods became apparent as a result of greatly increased interest in the use of alternatives to animal experimentation in research and testing. The close association which had developed between the University of Nottingham and FRAME made the University the logical location for such a laboratory. The FRAME Alternatives Laboratory (FAL), now headed by Richard Clothier, was opened in 1991. Work at the FAL is primarily focused on the development of in vitro models for skin toxicity testing. Studies began with the aim of developing in vitro methods to replace the use of animals in skin metabolism studies. Preliminary work has compared the levels of enzymes in human keratinocyte cell lines with those of freshly isolated keratinocytes from human skin samples. Of major interest at the present time, especially in Europe, is the development of alternative methods which can predict the potential of cosmetic ingredients to cause skin irritancy and to cause adverse reactions in the skin upon exposure to sunlight (phototoxicity). Experiments at the FAL have been conducted to assess the suitability of various human keratinocyte cell lines for use in phototoxicity assays. Keratinocyte cell lines in vitro possess a variable ability to terminally differentiate and it is important to establish to what extent the cell lines have retained their ability to express relevant markers, such as keratins, throughout the process of transformation and continuous culture. Four cell lines are being examined for their ability to express certain keratins. Differentiation can also be assessed by Rhodamine B staining, and the effectiveness of the Rhodamine B stain is being investigated using cell lines. The vascular system plays an important role in the skin's response to damaging effects by increasing vasodilation leucocyte adhesion and permeability, which leads to inflammation. The aim of a project at the FAL is to develop an in vitro method which closely models the above endpoints by using both primary human endothelial cells and human endothelial cell lines. Such a system could be used to assess the effects of irritancy mediators, metabolic products and photo-inducible chemicals which are produced as a result of exposure of human skin models to chemicals and sunlight. Recent studies have also shown that the monitoring of nitric oxide production might be a useful measure of the skin's inflammatory response in vitro. The above are just a selection of FRAME-funded projects currently being carried out. The results of some of these studies will hopefully go some way toward the implementation of the sixth amendment to the Cosmetics Directive (76/768/EEC) which states that "...testing on animals of ingredients or combinations of ingredients which should be banned as from 1 January 1998; ...that date should be postponed where alternative methods of testing have not been scientifically validated..." Reviews of the first 25 years of FRAME and the development and evaluation of in vitro tests by the FAL were published in ATLA 23(1) and are available from FRAME. Dr. Broadhead is scientific officer at FRAME | 
