LOS ANGELES, Jan 26 (Reuters) - American rapper and record producer Ye, formerly known as Kanye West, took out a full-page advertisement in the Wall Street Journal on Monday to apologize for antisemitic remarks that drew years of backlash. "I lost touch with reality," Ye wrote in the ad, attributing his behavior to an undiagnosed brain injury and an untreated bipolar disorder. Sign up here. "I regret and am deeply mortified by my actions in that state, and am committed to accountability, treatment and meaningful change. It does not excuse what I did, though. I am not a Nazi or...