Nu-Med said it completed its acquisition of substantially all of the assets of U.S. Health . . . Zytrex said it filed a voluntary petition for relief under Chapter 11 of the U.S. Bankruptcy Code . . . General Automation, an ailing Anaheim computer maker, said its stock will no longer be traded on NASDAQ's National Market System because the company's net worth fell below the required $375,000 . . . A federal judge in New York denied Storer Communications' request for a preliminary injunction barring an insurgent group of shareholders from soliciting or voting proxies for a May 7 shareholders meeting . . . Duff and Phelps placed the debentures and notes of Pacific Bell on its Watch List for possible lowering as a result of a California Public Utility Commission staff recommendation that the company's 1985 revenues be cut $480 million, rather than increased by $935 million, as PacBell has requested . . . Diversified Energies said it completed the acquisition of E. F. Johnson, a unit of Western Union, for $26 million in cash and the assumption of $35 million in debt.