Brown becomes fourth Oklahoma state champ to sign with OU    NORMAN, Okla. - Oklahoma Head Wrestling Coach Jack Spates announced today that Bristow prep star Derrick Brown signed a national letter of intent to compete for the Sooners next season.    A three-time state champion, Brown compiled a 141-11 record at Bristow High School. He finished third at state as a freshman. Brown also helped lead Bristow to six state championships - three dual and three tournament titles each.    "Derrick Brown is an outstanding scholar athlete who's a winner on and off the mat," said Spates. "Derrick is a 3.8 student who's interested in pursuing pre-medicine in college. He's a proven winner who not only won three individual titles while in high school but he also led Bristow High School to six team championships. Derrick's a focused and disciplined individual who will compete at 174 or 184 pounds. We're thrilled to welcome him to the Sooner wrestling family."    Brown joins fellow joins Oklahoma prep stars Beau DeArmon, Brandt Ward and Shane Kidd in this season's recruiting class.