boston.com News your connection to The Boston Globe
DISCOVERIES

Transplanted muscle cells may help repair heart tissue

TISSUE ENGINEERING

Doctors treat certain irregular heartbeats by implanting an artificial pacemaker that directly stimulates the main heart muscle. But artificial pacemakers are problematic, particularly in children, who often require repeated operations to adjust the device and replace the battery as they age. To develop a better alternative, researchers from Children's Hospital Boston have been studying the possibility of implanting immature muscle cells from another part of the body in the hope that they will grow into functioning heart tissue, fixing the arrhythmia without the need for an artificial pacemaker. Today , the researchers report the results of an experiment in which they successfully used this approach in lab rats. The transplanted cells survived for the entire lifetime of the rats and were capable of transmitting the heart's electrical signals nearly one-third of the time.

BOTTOM LINE: A new technique in which muscle cells are implanted in the heart to regrow damaged tissue has now been shown to work in rats.

CAUTIONS: The researchers had to work with healthy rats that did not have arrhythmias because it was not possible to induce the rhythm problems without damaging other important structures within the heart. The procedure may not work as well in rats that suffer from arrythmias.

WHAT'S NEXT: The researchers are trying to refine their technique to increase their success rate in restoring normal heartbeats.

WHERE TO FIND IT: The American Journal of Pathology, July 2006

MICHAEL E. HOCHMAN

DIABETES

Use of antidepressants is linked to diabetes

A new study suggests that taking antidepressant medications is associated with an increased risk for developing diabetes. Researchers from Johns Hopkins University studied more than 3,000 patients with early warning signs of diabetes but who did not meet criteria for the disease. Patients with evidence of depression at the beginning of the study based on their responses to screening questions were no more likely than mentally healthy patients to develop diabetes over the three-year study period. But those who were already taking antidepressant medications at the beginning of the study -- almost 6 percent of the subjects -- were at a two- to threefold increased risk. Notably, this didn't happen when the subjects taking antidepressants were also on a medication called metformin that is used to slow the development of diabetes. The reasons behind the connection between antidepressant use and diabetes remain unclear. It is possible that antidepressant medications trigger diabetes. Alternatively, patients taking antidepressants may tend to have more severe forms of depression that put them at risk for diabetes.

BOTTOM LINE: People taking antidepressant medications may be at an increased risk for developing diabetes, though the reasons for this connection remain obscure.

CAUTIONS: This study was presented at a meeting of the American Diabetes Association, but it has not yet been reviewed by other experts in the field and published in a journal.

WHAT'S NEXT: Although this study by no means proves that antidepressant use directly leads to diabetes, further research is warranted to assess this possibility, said study author Richard Rubin. For the time being, patients with depression -- even those at risk for diabetes -- should continue taking their medications, Rubin said.

WHERE TO FIND IT: The abstract is available for free at www.diabetes.org

MICHAEL E. HOCHMAN

CHEMISTRY

Surface tension explains Stooge's barroom trick

In a memorable episode of the comedy ``Three Stooges," Larry struggles to pull a glass off a bartop after setting it down in a pool of spilled water. As Larry discovered, a glass sitting in spilled water will ``glue" itself to the table. Recently, a group of European scientists used computer modeling to show why -- and to eventually solve industrial problems involving fluids. Larry's trouble comes from surface tension: the attraction between water molecules, table surface, and glass bottom, explains David van der Spoel of Uppsala University in Sweden . Van der Spoel's team calculated exactly how much energy it took to separate glass chips from one another, and why removing a glass from a puddle of alcohol would require much less energy than from water. Alcohol lowers surface tension, making it easier to produce a bubble of air beneath the glass. ``It's an easy, do-it-yourself, at-home experiment," says van der Spoel. But home experimentalist beware: When Larry's glass finally did come unstuck in the TV classic, sidekick Moe ended up with a faceful of beer.

BOTTOM LINE: A new computer model will address a barroom trick and prove useful in resolving industrial problems like ice clogs in oil pipelines.

CAUTIONS: The research has been done only at a microscopic level, and results may differ at a barroom scale.

WHAT'S NEXT: The team will expand the model to more-complex industrial systems. Quips Spoel: ``We're not just doing this for a good laugh."

WHERE TO FIND IT: Langmuir, June 20, 2006

NAILA F. MOREIRA

VONAGE Phone Service.
Fully-loaded calling plans just $14.99/month.
Click for more info!
http://www.vonage.com