Michael J. McCarthy, formerly a partner specializing in communications law for the Washington law firm of Dow, Lohnes & Albertson, has been named vice president and general counsel of A. H. Belo Corp. The Dallas-based media firm publishes The Dallas Morning News and owns an array of network-affiliated television stations. The appointment is effective Oct. 1.

Former newspaper publisher William P. Castronuovo has been appointed executive editor of The Reston Times and The Herndon Times in Fairfax County. Castronuovo, 26, a graduate of the University of Maryland and a former Washington Post layout editor, previously was owner and publisher of the Prince George's County Herald. He replaces Carl Hilinski, a six-year veteran of the Times who will become director of computer operations for Arundel Communications Inc., the papers' parent company.

Hager, Sharp & Abramson, a 12-year-old Washington public relations firm, has named Jasmine Isobe, former National Public Radio senior editor, as a senior associate. Isobe, also a former Congressional staff assistant and information director for the National Consumers League, handled promotions for NPR's news programs.

James M. Dolan, formerly administrative assistant to Rep. Barney Frank (D-Mass.) and a veteran election campaign consultant, has been appointed partner and vice president of Washington Resources and Strategy Inc., a national political and financial consulting firm headed by William Sweeney, the former deputy Democratic National Committee Chairman.