Focus | April 8, 2005


Contents Pulmonology Complexity Genetics Education Research Briefs Bulletin Forum Related Sites WebWeekly Lab Works StudenTalk Harvard Medical School
	April 8, 2005 PULMONOLOGY: Anatomy of an Asthma Attack The timing and severity of an asthma attack can be a mystery to asthma sufferers. A study published online March 16 in Nature offers a new model for understanding the behavior of the asthmatic lung during such a crisis. The researchers, led by Jose Venegas (on right) and Tilo Winkler, discovered patterns of constriction in the lung that mimic those seen in complex systems in nature. The model offers a new way to understand how smooth muscle constriction in the lung can lead to catastrophic changes in lung function.
	COMPLEXITY: Precursor Cells Follow Different Paths to Same Cell Fate How do developing cells emerge from the thicket of genetic possibilities to become cells of a particular type? HMS researcher Sui Huang and his colleagues have provided the first experimental confirmation that a developing cell is guided toward its fate by the stability-seeking behavior of its entire network of genes and proteins. This contrasts with the view held by many molecular biologists that development is the result of the turning on and off of a specific sequence of genes that essentially instructs the cell what to become. The study appears in the April 1 online Physical Review Letters.
	GENETICS: Gene Network Predicts Stroke Risk in Sickle Cell Anemia A single genetic mutation causes sickle cell anemia, but a more complex array of genetic variations controls the severity of the disease and its complications, such as stroke. By age 20, as many as 11 percent of people with the disease will suffer a brain attack. But current tests can predict only a fraction of those at high risk. In the April Nature Genetics, Marco Ramoni and his colleagues report that 25 variations in 11 genes can predict the risk of stroke with near certainty in children and teenagers with sickle cell anemia. The researchers eventually hope to use the model to predict stroke in the general population.