Sickle cells get tripped up by sticky ones  BROWN (US) — Using
computer models, researchers have discovered it’s a sticky type
of red blood cell that starts the blockage that leads to a
“sickle cell crisis.”  The models show that the rigid, crescent-
shaped red blood cells that are the hallmark of sickle cell
disease don’t cause these blockages on their own. Instead,
softer, deformable red blood cells known as SS2 cells start the
process by sticking to capillary walls. The rigid sickle-shaped
cells then stack up behind the SS2s, like traffic behind a car
wreck.  While sickle-shaped cells are the hallmark of the
disease, they’re not the only type of red blood cell present in
people with the condition. (Credit: Rob Pongsajapan/Flickr)
“This is the first study to identify a specific biophysical
mechanism through which vaso-occlusion takes place,” says George
Karniadakis, professor of applied mathematics at Brown
University and the study’s senior author. “It was a surprising
result because the common wisdom was