1. Regional Toxicology Laboratory, Dudley Road Hospital, Birmingham B18 7QH
2. Department of Chemical Pathology, University of Witwatersrand Medical School, Johannesburg, South Africa
3. Medscreen Ltd, London E14 9QZ
4. Department of Clinical Biochemistry, Fazakerley Hospital, Liverpool L9 7AL
5. Poisons Unit, New Cross Hospital, London SE14 5ER, UK