Dr. Chris van Tulleken

Alexander "Xand" van Hoogenhouck-Tulleken and Christoffer "Chris" van Hoogenhouck-Tulleken, known as "Dr. Chris" and "Dr. Xand" are British doctors, television presenters and identical twin brothers. They are best known for presenting the children's series Operation Ouch! Chris has become well known for his two-part television special for BBC One entitled The Doctor Who Gave Up Drugs. Xand has also presented shows without his brother.