An important choreographer of the complicated dance of signals, enzymes and proteins that takes embryonic stem cells through the steps to becoming a beating heart muscle cell is the gene Sox17, said researchers from Baylor College of Medicine in a report in the current issue of the Proceedings of the National Academy of Sciences. To be precise, Sox17 is critical in transforming primitive mesoderm (an early layer of tissue in the embryo) into the more specialized cardiac mesoderm from which heart muscle develops, said Dr. Michael Schneider, senior researcher of the report. "Heart muscle formation by embryonic stem cells is a complex, multi-step process," said Schneider, professor of medicine, molecular and cellular biology, and molecular physiology and biophysics at Baylor College of Medicine. "We have succeeded in uncoupling the formation of cardiac mesoderm from its antecedent steps. That discovery provides immediate insight into how one might …

Before letting young athletes play like the pros, know the risks – both physical and mental – of putting undeveloped muscles and bones to the test. Dr. Joseph Chorley, assistant professor of pediatrics at Baylor College of Medicine in Houston, suggests parents wait for indicators of physical maturity before allowing their children to engage in intense, physically demanding activities and year-round sports. Indicators for boys include needing to shave and for girls, the beginning of menstruation, said Chorley, who is also a sports medicine specialist at Texas Children's Hospital. "It is difficult to set an age at which kids should be allowed to throw a curveball (which puts undue stress on the shoulder and elbow) or play their sport of choice year-round," he said. "At 14, kids are at such different developmental stages than one another that the decision needs to be individualized." Exposing a body too soon to intense physical …

When amounts of a small protein called TCTP (translationally controlled tumor protein) are reduced in the cells of fruit flies, they are smaller than normal, indicating that the protein plays a major role in the growth and proliferation of cells, said researchers at Baylor College of Medicine in a report in current issue of the journal Nature. Work in his laboratory shows that TCTP plays a role in regulating Rheb (Ras homologue enriched in brain), a protein controlling growth and differentiation, and may give clues to treatment of a particular benign disease called tuberous sclerosis that is associated with the control exerted through the same pathway, said Dr. Kwang-Wook Choi, associate professor of molecular and cellular biology at BCM and his colleagues. When flies completely lack the protein, they do not live very long. However, when flies have only a little TCTP in their cells, they are very small, said Choi. Graduate student Ya-Chieh Hsu, through a series …

Democratic leaders in Congress reject many of the president's proposed cutbacks.

Doctors are impressed by the thoughtfulness of the governor's proposal, but some provisions, such as scope-of-practice expansions, are raising red flags.