Globalization and health, Patients in North, guinea-pigs in South ?

The North has established extremel strict principles and regulations in the field of human medical experimentation. "Enlightened consent" is demanded of patients recruited uniquely on a volunteer basis. But do these principles apply in the South, where ethical commissions are often to some degree ineffective or even non-existent, and where medical trials are frequently the only way poorer patients can gain access to treatments that would otherwise be financially out of reach? How then does one become involved in such experiments in Nigeria, Thailand, Senegal, or in Europe ?