1. Medical Research Laboratory, Nairobi, Kenya; Makerere University College Medical School, Kampala, Uganda; and King George VI Hospital, Nairobi, Kenya.
2. Methcal Research Laboratory, Nairobi, Kenya. Present address: Delta Clinic, Port Harcourt, Nigeria, West Africa.
3. Makerere University College, Medical School, Kampala, Uganda.
4. Head and Neck Unit, King George VI Hospital, Nairobi, Kenya, and Associate Scientist, Sloan-Kettering Institute for Cancer Research, New York, N. Y.