Two large new studies in The American Journal of Psychiatry suggest that treatment of depression, either with psychotherapy or drugs, reduces the risk of suicide attempts in all age groups, especially during the first months of treatment, contradicting earlier evidence that all antidepressant drugs could increase the risk of suicide in children and adolescents. In one, researchers led by Dr. Gregory E. Simon, a psychiatrist with the Center for Health Studies in Seattle, reviewed the records of 109,356 people being treated for depression in Washington state and northern Idaho. They found that suicide attempts were most common in the month before treatment began, declined sharply in the month after it began, and tapered off in the following six months. All treatments—psychotherapy, medication or both—showed the same pattern, suggesting that treating depression reduced suicide risk regardless of technique. The second study was led by Robert D. Gibbons, director of the Center for Health Statistics at the University of Illinois at Chicago. Using medical data from the Veterans Health Administration, researchers found that among 226,866 adults with depression, the overall rate of suicide attempts after beginning treatment with a selective serotonin reuptake inhibitor, or SSRI, was about one-third the rate of those who received no antidepressant at all.Microscopic ray of floodlightHow to make light without generating a lot of heat has been a burning issue for researchers who want to observe at close hand the biology of living cells. Peter Pauzauskie of UC Berkeley has invented a kind of microscopic floodlight out of potassium niobate crystal, which conducts laser light through a tiny wire. One thousand times thinner than a human hair, the wire is small enough to be inserted into a cell membrane. Gene transfer: A bug’s storyCraig Venter, the legendary entrepreneur who decoded the human genome, has taken an important step toward fashioning an entirely man-made organism. Scientists at his institute, writing in the journal Science, have for the first time successfully replaced an entire genome of a bacterial cell with one from a closely related species. They extracted the DNA of Mycoplasma mycoides, a bacterium that causes mild disease in goats, and implanted it into Mycoplasma capricolum, another goat pathogen. What happened? Goat bug B began behaving like goat bug A— sort of like Dolly the sheep, only with bacteria. The technique has no direct practical use yet, but it shows that it’s possible to clone a cell from DNA alone. The ultimate goal: to make a synthetic genome and insert it into an empty cell, thereby creating a new form of life.Now all scientists have to do is successfully invent a new genome. How long will that take? That’s the magic question. Coming up with tiny designer catalytic particlesThe shape or structure of a catalytic particle can determine how efficient it is at stirring a reaction. Chemists spend a lot of time trying to come up with ways to design a particle to perform in a specific way. Progress toward better particle design is reported by Peidong Yang of the University of California, Berkeley, and colleagues in the journal Nature Materials. They have grown tiny crystals of palladium in specific shapes, using “seeds” of even smaller crystalline cubes of platinum.The platinum cubes, which are only about 10 nanometers wide, are put in a solution containing a palladium compound. The palladium, which has a crystalline structure similar to platinum’s, grows on the faces of the cube. Left alone, the result is a palladium cube that is roughly 30 nanometers wide. But by introducing nitrogen dioxide into the solution, the researchers found they could alter the shape of the palladium crystal, ending with either an octahedron (with eight sides) or a cuboctahedron (with 14).
