Researchers at Oregon Health Sciences University have made a discovery that could be controversial, and could help prevent babies from inheriting certain rare diseases.  The research is controversial, because they create embryos from one man and two women.  OHSU researchers say they are not using the embryos to produce children.   And it's not clear when or if this technique will be put to use.  It could lead to a method that would allow genes that lead to rare and incurable diseases to be removed, so babies don't inherit the disease.  Similar research was stopped in Britain because of ethical issues.  The British government is taking public comment before it decides whether researchers can move forward.