Rebuilding will be the dominant theme in the East Regional as most teams were hit hard by losses from last season.    One exception may be Howard, which finished fourth in the East Regional last year but is poised to make a run at the championship this year.    Regional champions Derek Butts (133) and Adrian Thompson (heavyweight) both return for Howard after competing in last March's NCAA tournament. Senior Ephraim Walker (165) is the highest returning placewinner in his weight class.    Howard sophomore Reginald Torrence also is looking for a big season after dropping three weight classes from 149 to 125.    Slippery Rock lost both its national qualifiers from last season, but should still be a contender for the regional title. The team is led by junior John Opfar (184), who was a regional finalist last season.    Slippery Rock junior Adam Renner was third in the region last year, but should make a run at nationals as the region's only returning placewinner at 125.    Slippery Rock's lineup also will be bolstered by the return of senior Chris Matarrese at 133. Matarrese was a regional champion two years ago.    National qualifier Jeff Moskyok (184), a junior, will lead the way for Duquesne, last year's regional runner-up.    Duquesne junior Bill Boeh (165) is hoping for a reversal of fortune after slipping to fourth in the region last year. Boeh was an NCAA qualifier two years ago.    Defending East Regional champion Millersville will have a tough time repeating as it lost most of its lineup from last season.    Millersville does welcome back Greg Eynon (184) and Tyler Woolever (heavyweight), who both finished second in the region a year ago.    Eynon is expected to drop down a weight this year to make room for Adam Schaaf at 197. Schaaf qualified for the NCAA Tournament in 2000.    Delaware State, fifth in last year's region, will hope to improve this season. John Smith (149) may be the team's best bet for a regional championship.