1. Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
2. University of Ibadan, Ibadan, Oyo, Nigeria
3. College Of Medicine, Lagos University Teaching Hospital, Idi-Araba, Lagos, Nigeria
4. University of Iowa, Iowa City, IA, USA
5. University of Dundee, Dundee, UK
6. University of Pittsburgh, Pittsburgh, PA, USA