A recent email gave me hope that innocence was not dead yet. The sender, a scientist, waxed indignant that I suggested in a recent column that the source of funding can affect the results of experiments. She assured me that the scientific method is strong enough to resist any such pressure.

Imagine my dismay, then, when I saw a study in tonight’s issue of PLoS Medicine which found that the identity of the sponsor of a study of the effectiveness of statins, the blockbuster cholesterol-lowering drugs, affected the study’s conclusions. Specifically, in nearly 200 head-to-head comparisons of statins such as Lipitor or Crestor or Mevacor, the results were more likely to favor the sponsor’s product than the competition: in 66 percent of the studies the sponsor’s drug came out ahead, compared to 10 percent in which the competitor’s drug did. (Other studies were government-funded.)

Why the disparity? Not clear, admit Lisa Bero and colleagues at the University of California, San Francisco. One possibility is that drug companies choose lower dosages for the comparison drug. A more likely one, it seems to me, is the file-drawer effect: if the results aren’t what you hoped, instead of writing it up and sending it off for publication in a medical journal you just file it away, never again to see the light of day (or print). Read it for yourself, here (the PLoS journals have the enlightened policy of making all their papers free; no subscription or per-article fee required). I especially liked this graph:

Maybe it’s not innocence that isn’t dead . . . but naivety.

A favorite tactic of right-wing activists opposed to research with human embryonic stem cells is to sneer something like, “ah, it’ll never work, and you’ll have killed (sic) all those babies (sic) for nothing.” While scientists have been known to exaggerate the potential benefits of their research, when it comes to stem cells they have actually been pulling back, trying to inject a dose of reality into the hope/hype machine that has convinced big chunks of the public that cures for stroke, Alzheimer’s, Parkinson’s and other awful brain diseases are just around the corner—the corner where stem cell studies break free of the shackles President George Bush imposed on them in August 2001.

Except that their studies keep showing that barriers to using stem cells therapeutically are not insurmountable at all. In the latest coup, researchers have transplanted human neural stem cells into the brains of rats and mice, traced the cells’ travels, and found that they navigate toward areas damaged by stroke. Stanford neuroscientist Gary Steinberg and colleagues were able to trace the cells’ travels because they slipped minuscule bits of iron inside the cells so that MRI could detect them. As the scientists are reporting tonight in the online edition of the Proceedings of the National Academy of Sciences, the iron doesn’t hurt the cells: the neural cells behaved just as they without the iron. That suggests that a similar tag could be used safely if stem cells are transplanted into human patients, allowing physicians to track their progress.