31.   Burzynski originally developed the drugs, which he calls antineoplastons, from human urine.

32.   But as financing for malaria research has shrunk, new drugs are being developed more slowly.

33.   But Gillette is using rodents in a program to develop prescription drugs.

34.   But Fisher, who uses the radioactive elements to develop new drugs, said isotopes are sometimes difficult to obtain.

35.   But by acquiring a drug company, Amgen might be acknowledging the difficulties it has had developing drugs of its own.

36.   But it will take years of research to determine whether such drugs can be developed.

37.   But other experts say that what deters companies from developing those drugs is mainly the small market size, not the lack of patent protection.

38.   But it is the proteins that actually carry out bodily functions, and drugs are developed to bind to particular proteins.

39.   But pressure was growing on the company to show that it could actually develop a drug.

40.   But researchers are on the brink of developing other drugs, he says.