WASHINGTON, D.C. November 18, 2009 -- When people have malaria, they are infected with Plasmodium parasites, which enter the body from the saliva of a mosquito, infect cells in the liver, and then spread to red blood cells. Inside the blood cells, the parasites replicate and also begin to expose adhesive proteins on the cell surface that change the physical nature of the cells in the bloodstream.
Experiments show that infected red blood cells are stiffer and stickier than normal ones -- in the later stages of the disease, up to 10 times stiffer. They also tend to adhere to the endothelial cells lining the vasculature, affecting the normal blood flow. This explains some of the common symptoms of malaria, such as anemia and joint pain.
Sticking to the walls of blood vessels is a survival mechanism for the parasite. In order to develop completely, it needs several days inside a red blood cell. Even though parasitized cells are nearly invisible for the immune system, they may be destroyed in the spleen while circulating freely in the bloodstream.
Doctoral student Dmitry Fedosov and Brown University professor George Karniadakis are studying how malaria infections affect the physical properties of red blood cells, and alter normal blood flow circulation. In particular, they examine an increase in blood flow resistance, and dynamics of infected cells in the bloodstream.
They also monitor the mechanical properties of infected red blood cells by measuring membrane temperature fluctuations, and through the response of a "microbead" that is attached to the cell and twisted. The measured properties are then used in modeling the flow of red blood cells in people infected with malaria. They also collaborate with the group of professor Subra Suresh at MIT, who obtain experimental measurements of the properties and the flow of healthy and infected cells.
"Our model predicts the dynamics of malaria-infected RBCs in the bloodstream, which anticipates the possible course of the disease," says Fedosov.
Recently they found that temperature fluctuations of infected red blood cell membranes measured in experiments are not directly correlated with the reported cell properties, hence suggesting significant influence of metabolic processes. They measured an increase in resistance to blood flow in the capillaries and small arterioles during the course of malaria and found that parasitized red blood cells have a "flipping" motion at the vessel wall that appears to be due to stiffness of the infected cells. The developed models will aid to make realistic predictions of the possible course of the disease, and enhance current malaria treatments.
The talk "Multiscale modeling of blood flow in cerebral malaria" by Dmitry Fedosov, Bruce Caswell, and George Karniadakis is at 6:12 p.m. on Sunday, November 22, 2009.
MORE MEETING INFORMATION
The 62nd Annual DFD Meeting will be held at the Minneapolis Convention Center in downtown Minneapolis. All meeting information, including directions to the Convention Center is at: http://www.dfd2009.umn.edu/
Credentialed full-time journalist and professional freelance journalists working on assignment for major publications or media outlets are invited to attend the conference free of charge. If you are a reporter and would like to attend, please contact Jason Bardi (firstname.lastname@example.org, 301-209-3091).
Main meeting Web site: http://meetings.aps.org/Meeting/DFD09/Content/1629
Searchable form: http://meetings.aps.org/Meeting/DFD09/SearchAbstract
Local Conference Meeting Website: http://www.dfd2009.umn.edu/
PDF of Meeting Abstracts: http://flux.aps.org/meetings/YR09/DFD09/all_DFD09.pdf
Division of Fluid Dynamics page: http://www.aps.org/units/dfd/
Virtual Press Room: SEE BELOW
VIRTUAL PRESS ROOM
The APS Division of Fluid Dynamics Virtual Press Room will contain tips on dozens of stories as well as stunning graphics and lay-language papers detailing some of the most interesting results at the meeting. Lay-language papers are roughly 500 word summaries written for a general audience by the authors of individual presentations with accompanying graphics and multimedia files. The Virtual Press Room will serve as starting points for journalists who are interested in covering the meeting but cannot attend in person. See: http://www.aps.org/units/dfd/pressroom/index.cfm
Currently, the Division of Fluid Dynamics Virtual Press Room contains information related to the 2008 meeting. In mid-November, the Virtual Press Room will be updated for this year's meeting, and another news release will be sent out at that time.
ONSITE WORKSPACE FOR REPORTERS
A reserved workspace with wireless internet connections will be available for use by reporters. It will be located in the meeting exhibition hall (Ballroom AB) at the Minneapolis Convention Center on Sunday and Monday from 8:00 a.m. to 5:00 p.m. and on Tuesday from 8:00 a.m. to noon. Press announcements and other news will be available in the Virtual Press Room.
GALLERY OF FLUID MOTION
Every year, the APS Division of Fluid Dynamics hosts posters and videos that show stunning images and graphics from either computational or experimental studies of flow phenomena. The outstanding entries, selected by a panel of referees for artistic content, originality and ability to convey information, will be honored during the meeting, placed on display at the Annual APS Meeting in March of 2010, and will appear in the annual Gallery of Fluid Motion article in the September 2010 issue of the journal Physics of Fluids.
This year, selected entries from the 27th Annual Gallery of Fluid Motion will be hosted as part of the Fluid Dynamics Virtual Press Room. In mid-November, when the Virtual Press Room is launched, another announcement will be sent out.
ABOUT THE APS DIVISION OF FLUID DYNAMICS
The Division of Fluid Dynamics of the American Physical Society exists for the advancement and diffusion of knowledge of the physics of fluids with special emphasis on the dynamical theories of the liquid, plastic and gaseous states of matter under all conditions of temperature and pressure. See: http://www.aps.org/units/dfd/
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