41.   Various studies have raised the possibility that douching can have adverse effects.

42.   While imperfect, such animal models can be substituted when human studies raise moral concerns.

43.   Yet both he and McGlashan are well aware of the difficult questions their studies raise, and they have both gone to some lengths to address them.

44.   Others say the studies raise questions about the safety of all calcium channel blockers.

45.   A large study raises the possibility that consuming lots of milk and other dairy products may modestly raise the risk of prostate cancer.

46.   A new study raises the possibility that people who drink a lot of coffee might be more likely to develop the debilitating immune system disease rheumatoid arthritis.

47.   A new study raises doubts about the safety of installing filters in the veins to try to stop dangerous blood clots from lodging in the lungs.

48.   A new study raises questions about how the law will define failure.

49.   A surprising new study raises questions about the effectiveness of hormone supplements containing estrogen in warding off heart trouble in older women.

50.   But a few small studies have raised concern.