Chennai, Jan 30: Prime Minister A B Vajpayee today rang up DMK president M Karunanidhi to inquire about the health condition of Union minister Murasoli Maran who underwent a heart surgery in a US hospital yesterday. Vajpayee expressed happiness when Karunanidhi told him that Maran was progressing well after the surgery, a DMK release said. Karunanidhi is the maternal uncle of Murasoli Maran, now a minister without portfolio in the Union cabinet. Bureau Report