In that account, Howard Pomeranz of the University of Minnesota Medical School also noted seven other cases that had previously been mentioned in the medical literature.

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"If you're male, you're going to have to go through the rectum, " said Dr. Sayeed Ikramuddin, director of gastrointestinal surgery at the University of Minnesota Medical School.

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"All drugs given to populations work in some members of the population and not others, " says Jay Cohn, a cardiologist at the University of Minnesota Medical School in Minneapolis.

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Only about 20% of male-to-female transgender people have had genital reconstruction surgery, and only about 5% of female-to-male, estimates Walter Bockting, a psychologist at the University of Minnesota medical school who has 20 years of clinical experience working with transgender patients.

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When a high school classmate mentioned the wonders of ferrate, Daly (who turned down a bid to medical school at the University of Minnesota) decided to pour part of his fortune into tackling the clean water problem.

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