ο Safrole

I N V E S T I G A T I O N

SUSPECT SAFROLE Chicago police probe orders of drug precursor from Northwestern University

O RDERS PLACED W I T H A chemical supply company by an unnamed person

claiming to be with Northwest­ern University have touched off a fraud investigation by the Chica­go Police Department, with the added involvement of the feder­al Drug Enforcement Adminis­tration (DEA).

At issue are a series of orders for the chemical safrole from Sig-ma-Aldrich. Safrole, an essential oil, is a listed chemical with DEA because, along with legitimate us­es, it can also be used to manu­facture illegal drugs—for exam­ple, methamphetamine.

The DEAlisting of safrole (and other chemicals) means that for orders above a certain quantity, chemical suppliers must notify DEA. Sigma-Aldrich Chief Ad­ministrative Officer Mike Hogan says that the Northwestern or­ders for safrole never reached those quantities but that the company routinely double-checks orders for any DEA-list-ed chemical.

The case under investigation began with an order for safrole placed in early September 2003. A supervisor called the person who placed the order and questioned the address given for shipment.

"He said he's at Loyola [Uni­versity] now, and he had given us the wrong address. That caused us to stop shipment, but it was too late—somebody had already picked it up," Hogan says. "We went to DEA."

At least two more attempts to place orders for safrole through the Northwestern pur­chasing system have been made with Sigma-Aldrich since Sep­tember, Hogan says. The com­pany has not filled those orders and has notified DEA on both occasions.

Northwestern officials will not comment on the investigation. Chicago Police Department spokesman Patrick Camden con­firms that police are conducting a fraud investigation of chemi­cal supply orders originating at Northwestern—specifically, de­livery of $3,608.78 worth of chem­icals and equipment to a Chicago address.-WILLI AM SCHULZ

B I O M I N E R A L I Z A T I O N

Blood Cells Deliver Raw Materials For Oyster Shells

Oysters rely on a special­ized kind of blood cell to deliver the calcium car­

bonate crystals they need to build their shells, according to a new report. The finding con­tradicts conventional wisdom about shell growth mecha­nisms and may hold valuable clues to improving methods for cultivating pearls.

Oysters and other mol-lusks surround themselves with a thin layer of organic material lining their protec­tive shells. Scientists had as­sumed that this extracellular organic matrix was wholly re­sponsible for shell growth: It was thought to directly nucle­ate calcium carbonate crys­tals from the surrounding so­lution, to regulate crystal growth and shape, and to ter­minate crystal growth.

But new work from adjunct

assistant professor Andrew S. Mount and his colleagues at Clemson University in South Carolina suggests that this model of shell growth needs to be revised. Using scanning

electron microscopy and X-ray microanalysis, Mount's team has shown that a class of immune celts in oysters' blood actually delivers the calcium carbonate crystals

required for shell building [Science, 304, 297 (2004)]. In the electron micrograph shown, these crystal-carrying immune cells (green) are in­teracting with the crystalline structures (gold) at the min­eralization front. (The organic matrix is shown in blue.) Mount's team has also ob­served the cells releasing their crystal cargo at these sites. There, the nascent crystals are remodeled into plates that make up new shell.

Cultured pearls likely grow using the same mechanism, Mount says. But whether im­mune cells play a similar role in other biomineralization processes remains to be seen, he acknowledges. Still, his findings may cause re­searchers to take another look.-AMANDA YARNELL

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