WASHINGTON — Under fire for its role in providing fetal tissue for research, Planned Parenthood asked the government's top health scientists Wednesday to convene a panel of independent experts to study the issues surrounding the little-known branch of medicine. Planned Parenthood's request to the National Institutes of Health came as Senate Republicans pressed their fight to bar the organization from receiving federal aid. Likely opposition from at least one GOP senator highlighted the long odds the GOP will face in a Senate showdown vote expected early next week. The group also took its websites down after a hacker attack it...