    Sentence 1: Researchers at Sweden 's  Karolinska Institute reanalyzed data from  more than 2,000 infants who had been  treated with radiation for a benign birthmark  condition between 1930 and 1959.    Sentence 2: Researchers at Sweden 's  Karolinska Institute recently went over data  from more than 2,000 children treated with  radiation for a harmless birthmark condition  between 1930 and 1959.