Cell Biology: One-way Calcium Channel Pinpointed Within the Cell Neuroscience: Knocking Down Cell Cycle Protein Picks Up Axon Growth Microbiology: Early Step in Protein-folding Revealed by Bacterial Mutant Milestone Symposium 5 Hope, Caution Expressed About Stem Cells Milestone Symposium 4 Speakers Unmask Molecular Players in the Brain Dental Practice: Dentistry's Future Glimpsed at Leadership Forum Green Campus Initiative: Harvard's Longwood Schools Grow Greener Outreach: Medical Team Aids Earthquake Relief in Iran Second-year Show: Students Rollick Along the Low Road in Second-year Show New Books: The Winter Bookshelf   Protein-Protein Interactions Mapped for C. elegans Reading Expressions: A Skill Toward Becoming A Better Doctor? High Intake of Vitamin D Supplement May Cut Risk of Multiple Sclerosis Nuclear-export Inhibitors Found In Cell-based Screen   Appointments to Full Professor HSPH Awarded $20.5m Biodefense Grant Nominations Sought for Dean's Awards to Advance Women FDA Commissioner Speaks at Next Milestone Symposium HSPH Calls for Myrto Lefkopoulou Lecture Award Nominees News Brief Honors and Advances In Memoriam: David Bray James Roberts David Freiman William Montgomery   A Joke as Cover for Sexism and Violence   Medicare Drug Benefit May Unsettle Some Stomachs   Front Page

MILESTONE SYMPOSIUM 5 Hope, Caution Expressed About Stem Cells Careful studies may be providing both a reality check on some of the hype about stem cells and a rationale for more support of research into their basic biology and clinical applications. This was the message of leading stem cell researchers gathered on Jan. 15 for the fifth HMS Milestone event, a series of scientific symposia developed to celebrate the School's new research building and the 100th anniversary of the groundbreaking for the Longwood Quadrangle. "When my liver fails, don't give me a bone marrow transplant, give me a liver," said Irving Weissman, keynote speaker at the Milestone Symposium on stem cells. (Photo by Steve Gilbert) "There is a critical need for regenerative medicine driven by changing demographics," said moderator David Scadden, HMS professor of medicine and director of the Center for Regenerative Medicine at Massachusetts General Hospital. "The proportion of the population over 65 is expected to double at midcentury. The most costly care is not for the acutely ill, but for those with chronic organ failure." Stem cells may help meet this medical challenge if scientists can grow them into specialized cells or even replacement parts. But the term stem cells can refer to several different types of cell, such as the inner cells of the blastocyst, commonly referred to as embryonic stem cells, which can form every type of cell in the adult. Scientists have reported stem cells in adults, but they are typically able to make only different types of their own tissue, such as specialized blood cells from stem cells in bone marrow. In perhaps disappointing news, there is no evidence that insulin-producing beta cells in the pancreas are regenerated from adult stem cells or other progenitor cells, according to Douglas Melton, the Thomas Dudley Cabot professor in the natural sciences at Harvard University. "There is abundant evidence in the literature for abundant turnover and replication of beta cells," said Melton. So postdoctoral fellow Yuval Dor asked how healthy adult mice maintain their beta cells. The evidence, Melton said, "all points to maintenance by beta cell duplication." Now, Melton and his lab will try to purify and boost replication of beta cells from cadavers and redouble their efforts to reproduce the natural development cycle that produces beta cells from embryonic stem cells. He offered new resources to his colleagues everywhere. "We have isolated 17 new human embryonic stem cell lines, and they are available to all researchers to use for any purpose," Melton said. Keynote speaker Irving Weissman, director of the Institute for Cancer and Stem Cell Biology and Medicine at Stanford University, argued for more rigorous study before stem cells are taken to clinical trials. In one case, his lab has not been able to reproduce results from a published report in the journal Nature that said enriched stem cells from an animal's blood will regenerate cardiac muscle, blood vessels, and smooth muscle tissue. Yet at least five clinical trials are testing injected stem cells in the hearts of people with mild cardiac infarctions, said Weissman, who was the first to identify and isolate the blood-forming stem cell from mice. Other studies from his lab show that bone marrow stem cells circulate throughout the body, where researchers may mistakenly identify them as adult stem cells belonging to other tissues. --Carol Cruzan Morton