NEW YORK (AP) -- Shares of some top health care equipment companies are down at 10 a.m.: Becton Dickinson fell $.35 or .5 percent, to $68.95. Covidien fell $.31 or .8 percent, to $37.06. Patterson fell $.10 or .4 percent, to $26.41. PerkinElmer fell $.25 or 1.2 percent, to $20.33. Thermo Fisher fell $.49 or 1.1 percent, to $42.16. Varian Medical fell $.42 or .8 percent, to $51.66. Waters fell ...