The 12th annual musical soiree of the CAS astronomy and physics departments, Friday, April 26, 7 p.m., Tsai Performance Center
Week of 19 April 2002 Vol. V, No. 31


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BU's Science and Technology Day on March 26 presented nearly 130 outstanding research posters by graduate students from both the Charles River and the Medical Campuses. Only 10 posters could be singled out for awards, but the judges remarked on the extraordinarily high quality of all the research, as well as the enormous diversity and range of disciplines represented. "Research Briefs" is highlighting this graduate research. For a list of awards, and access to abstracts of the work presented, visit

A clearer picture. GRS computer science department Ph.D. student Harrison Hong (GRS'04), winner of the Provost's Award at Science and Technology Day, is striving to make the work of radiologists and surgeons easier. Although modern imaging techniques such as CT scans provide very detailed information about internal organs, it remains difficult for physicians to see the information in its complete three-dimensional context. Being able to see the information this way would aid them in determining the exact size and precise location of problem areas in organs such as the lungs.

Also, radiologists must compare repeated studies of pulmonary nodules, growths in the lungs, to determine if a nodule is growing or changing shape and whether it is cancerous or benign.

Hong, a student of Margrit Betke, a CAS assistant professor of computer science, is developing a system to precisely align a series of CT images, X-ray-like images taken of multiple slices through the body. This image analysis system begins by segmenting out points on the surface of the lungs and reconstructing them in three dimensions, then anatomical landmarks in consecutive CT scans are used to set up an initial alignment of lung surfaces.

Using a more efficient algorithm developed by Hong, corresponding lung surface points are quickly matched. This matching process is repeated until the alignment is refined more and more accurately.

As the surface points move into better alignment, any nodules within the lung are also automatically aligned, saving radiologists considerable time by not having to match repeated studies manually.

Hong's and Betke's work on registration of CT lung surfaces was presented at the the Fourth International Conference on Medical Image Computing and Computer-Assisted Intervention, held in Utrecht, The Netherlands, in October 2001. More information as well as images can be seen at:

Friendly fire. Lymphocytes, B and T cells, are the body's defenders. They identify and disable damaging bacteria, viruses, and other potential health threats. But sometimes things go terribly wrong, and a situation akin to biological friendly fire develops. In these cases, lymphocytes attack the body's own cells, leading to serious autoimmune diseases such as lupus, rheumatoid arthritis, multiple sclerosis, and some forms of diabetes.

In work that recently earned her the President's Award at Science and Technology Day, Elizabeth Leadbetter (MED'02), a doctoral candidate in the department of microbiology and the Immunology Training Program at the School of Medicine, and her mentor, Microbiology Professor Ann Marshak-Rothstein, uncovered a critical chain of cellular events that triggers an autoimmune response. Their experiments reveal a two-step process.

They demonstrate that when certain receptors on the surface of B cells detect particular configurations of DNA (known as chromatin), they grab onto it, and drag it into a tiny, bubble-like sac inside the cell, known as an endosome. Within the endosome, if another receptor (toll-like receptor TLR9) binds to the chromatin, the autoimmune response is activated. If the TLR9 is blocked from binding, there is no response.

This finding explains why chloroquine, an antimalarial drug that blocks the operation of TLR9, is often of benefit to people with autoimmune diseases. This new information will enable researchers to design drugs that block TLR9's action, but do not produce the harmful side effects, such as retinal damage, that can accompany prolonged use of chloroquine.

A paper describing the work by Leadbetter and Marshak-Rothstein was published in the April 11 issue of the journal Nature.

"Research Briefs" is written by Joan Schwartz in the Office of the Provost. To read more about BU research, visit

19 April 2002
Boston University
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