Thank you for all the responses from John Clarke, Mark Kerr, Helen Weir and an anonymous person who kindly did a search in WoK and found : vol 26, is 3, p.A558. Suk Ying Library & Information Service Postgraduate Medical Education Centre University College London Hospital NHS Foundation Trust 4th Floor East 250 Euston Road London NW1 2PG Tel: 020 3447 8124 ------------------------------------------------------------------------ This email is confidential and is intended solely for the person or entity to whom it is addressed. If this is not you, please forward the message to [log in to unmask] We have scanned this email before sending it, but cannot guarantee that malicious software is absent and we shall carry no liability in this regard. We advise that information intended to be kept confidential should not be sent by email. We also advise that health concerns should be discussed with a medical professional in person or by telephone. NHS Direct can also provide advice. We shall not be liable for any failure to follow this advice. University College London Hospitals NHS Foundation Trust (UCLH).