Complex sentence: Dr. Michael Gallant (played by Sharif Atkins) was a regular character in the TV series "ER" from 2001-2004 (seasons 8-10).
Split into simpler sentences: Dr. Michael Gallant was a fictional medical doctor in the TV series "ER", portrayed by Sharif Atkins. He was a regular character from 2001 to 2004 (seasons 8-10).