A trial in which more than two dozen health care providers went after big tobacco companies for losses treating smokers was expected to last at least six months but reached closing arguments Wednesday in less than half that time. It appeared that time was saved when the defense rested its case after presenting just three witnesses and playing parts of video depositions. The nationally watched suit, filed in 1998 as the City of St. Louis v. American Tobacco, overcame legal challenges that kept about 160 similar cases around the country from reaching trial. Twenty-nine plaintiffs representing 37 health institutions, mainly local and regional operations across Missouri, are asking for more than $455 million in costs, plus punitive damages, from six tobacco companies. There had been 11 defendants, but the tobacco parent companies were dropped from the case in the past few days.