Complex sentence: Chopra obtained a medical degree in India before emigrating in 1970 to the United States, where he specialized in endocrinology and became a physician and Chief of Staff at the New England Memorial Hospital (NEMH).
Split into simpler sentences: Chopra obtained a medical degree in India before emigrating in 1970 to the United States. As a physician he specialized in endocrinology and became Chief of Staff at the New England Memorial Hospital (NEMH).