Two-thirds of the members serving on an expert medical panel investigating a U.S.-funded AIDS study are receiving grant money from the federal agency at the center of the probe, according to documents and interviews. The Institute of Medicine said it was aware of the financial ties with six of the nine members of its expert panel but approved their participation because they have special expertise, receive only a minority of their overall funding from the National Institutes of Health and won their grants competitively. The six panel members are receiving funds from NIH ranging from $120,000 to nearly $2 million a year, according to agency records and interviews by The Associated Press.