regulators. brown: paul solman looks at what happens when private equity firms use borrowed money to buy companies. debt, in my view, is not in and of itself a bad thing. it s when the debt is used to enrich a handful of private equity partners that s when it s dastardly. lehrer: kwame holman reports on a tension-filled week for the white house and democratic members of congress. brown: we get the weekly analysis of mark shields and david brooks. lehrer: and margaret warner reports on what a new early test for alzheimer s disease could mean for treatment. that s all ahead on tonight s newshour. major funding for the pbs newshour has been provided by: and with the ongoing support of these institutions and foundations. and. this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. lehrer: so far, so good that was the word from the gulf of mexico today. there were no signs