Some First Class stamps dostinex tablets 0.5 mg Shares of steelmakers Gerdau SA, UsinasSiderurgicas de Minas Gerais SA, or Usiminas, and CiaSiderurgica Nacional, or CSN, all fell on Tuesday,reversing two straight sessions of gains. (Reporting by Rodrigo Viga Gaier; Additional reporting byAlberto Alerigi Jr.; Writing by Guillermo Parra-Bernal; Editingby Gerald E. McCormick and Steve Orlofsky)