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Bioinformatics
“The interface of computer technologies and biology is going to
have a huge impact on society,” says Danny
Chen, Rooney Associate
Professor of Computer Science and Engineering. “The opportunities
for medical researchers and computer engineers and scientists to work
together to
solve real-life problems is tremendous. For example, I have been studying
robotics, more specifically mapping a path for a robot to follow, one
based on the parameters of a specific environment. The same methods that
allow me to determine a path for the kinds of motions a robot needs to
make to maneuver in its environment, without causing harm or being damaged
itself, are applicable in a variety of medical applications.”
Today when a surgeon begins planning for a specific operation, he or
she might review an X-ray or other images of the body. Individually,
those often prove inconclusive. “What we’re working on,” says
Chen, “is a human body tissue map, a topographical image that shows
tissues, organs, tumors, and their positions relative to one another.” A
body tissue map allows a surgeon to evaluate all options -- the costs,
consequences, and benefits of a particular path he or she may follow
in an actual surgical procedure.
This is especially helpful when dealing with radiation therapy. When
physicians identify a tumor site and want to bombard it with radiation,
one of their most important tasks is to avoid damaging organs and critical
tissues. Chen’s mapping paths, which identify safe routes for a
number of individual radioactive beams to enter the body from different
directions, have shown promise as a way to minimize the energy and amount
of radiation to normal tissues while concentrating the combined power
of all the beams on the tumor. “Our studies to date have been very
encouraging, but we are still evaluating this approach. If we find strong
evidence that our method out-performs the current methods, then we will
begin more strenuous clinical experiments in conjunction with our collaborator,
Cedric Yu, the director of Medical Physics at the University of Maryland
Medical Center in Baltimore.”
Computational biology, biocomplexity, artificial life, agent based modeling … these
are all terms defining computer simulations of complex physical phenomena,
from molecules to societies to entire ecosystems. “Biocomplexity,” says
Gregory R. Madey, associate professor of computer science and engineering, “studies
large numbers of diverse things and how they interact. Rather than developing
a lot of equations and trying to predict what’s going to happen
-- which is difficult mathematically when the items to be studied are
all different -- we build a model of the system and let it behave as
it would in real life.” One of Madey’s current projects involves
a collaboration with Patricia A. Maurice, associate professor of civil
engineering and geological sciences. They are modeling natural organic
matter, which plays a vital role in ecological and biogeochemical processes.
Two graduate students and two undergraduates work with Madey and Maurice
on the project. They are studying ecosystem function, the global carbon
cycle, and the quantitative aspects of organic carbon transfer in the
environment.
Jesus A. Izaguirre, assistant professor of computer science and engineering,
is also part of the biocomplexity initiative at the University, which
is directed by the Interdisciplinary Center for the Study of
Biocomplexity. Working with James A. Glazier, associate professor of physics, and Mark
S. Alber, professor of mathematics, Izaguirre is modeling the development
of avian limbs. “We’re not trying to engineer a better chicken
wing, although that might have interesting commercial applications,” says
Izaguirre. “The purpose of the project is to determine the physical
properties of cells and the tissue of a limb bud as it grows so we can
develop a computer model of the process.” Izaguirre believes that
the medical and scientific implications of the project are very exciting
and may lead to a better understanding of malformation and other diseases
associated with development.
Izaguirre also models large biological molecules such as protein, DNA,
and estrogen receptors. Simulating the behavior of these types of molecules
and how they interact as part of a drug, a disease process, or metabolic
function can help pharmaceutical engineers design new and more effective
drugs. For example, he is working with Martin P. Tenniswood, Coleman
Foundation Professor of Biological Sciences, to model the effectiveness
of anti-breast cancer drugs. “If you have a molecular model,” he
says, “you can understand the mechanisms and determine the effectiveness
of specific drug.”
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The Shapes of Things to Come
X-rays, CT scans, MRIs, and ultrasound scans are all imaging techniques
physicians use to form their diagnoses. “Image reconstruction
-- developing an accurate picture from the indirect measurements
created by these types of scans,” says Ken
D. Sauer, associate
professor of electrical engineering, “increasingly focuses
on three-dimensional data. Using any of a variety of medical imaging
modalities, we create the algorithms that transform non-invasive
measurements into a three-dimensional map of a particular section
of the body.” In the past physicians reviewing a conventional
X-ray received only part of the whole picture. They were able to
view structures in the body but not an accurate image of the orientation
or relationship of one organ or “structure” to another.
Sauer’s tomographic research, supported by the Indiana 21st
Century Research and Technology Fund and the General Electric Corporation
(GE) and in collaboration with researchers from Indiana University
and Purdue University, focuses on two types of imaging: emission
and transmission. In transmission imaging, such as an X-ray or CT
scan, the image is constructed from the amount of radioactivity that
transmits through the patient. In emission imaging, such as positron
emission tomography (PET), the patient either inhales or is injected
with a radioactive isotope whose subsequent emissions can be measured
by medical personnel using the scanning equipment. For example, some
tumors absorb certain types of glucose at higher rates than healthy
tissue. When this glucose is tagged with radioactive tracers, the
signals sent back during the scan can help identify the location
and size of the tumor, as well as how active it is.
“What is different about the methods we use” says Sauer, “is
that they’re based directly on the statistics of the data.
We assume the data received from imaging techniques has problems.
For instance, since only a limited amount of radioactive material
can be injected into a patient, the signals from those isotopes can
be relatively weak. So we explicitly include those limitations of
quality in our inverse problem solutions to create more accurate
images.”
Used as a research tool since the 1970s, in recent years PET has
become particularly useful for the detection of cancer, coronary
artery disease, and brain disease. The difference between PET and
other imaging techniques is that PET can show the chemical functioning
of organs and tissues, not just their physical structure. For example,
PET can be used to measure the metabolic rate of glucose in the brain,
which is helpful in locating the source of epileptic seizures and
dementias. The metabolic rate of glucose in the heart can also be
measured. PET scans can identify tumors, as well as disorders such
as Parkinson’s disease. They can also monitor blood flow in
the brain, which helps to identify which regions of the brain are
responsible for performing specific tasks. One of the most recent
commercial applications of tomographic imaging techniques is the
combination of a CT (transmission) scanner and a PET (emission) scanner.
The new scanner creates a marriage of information -- based on algorithms
and inverse problem solutions -- that provides both structural detail
and physiological function, a diagnostic tool that offers great insight
to physicians while often catching diseases in their early stages. |
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The Interdisciplinary Center
for the Study of Biocomplexity
Comprised of researchers throughout the University, the Interdisciplinary
Center for the Study of Biocomplexity focuses on the unique, yet complex,
structures and behaviors of biological entities -- such as molecules,
cells, or organisms -- and the variety of spatial and temporal relationships
that arise from the interaction between such entities.
DEPARTMENTS
Aerospace and Mechanical Engineering
Glen L. Niebur, assistant professor
Biological Sciences
Crislyn D’Souza-Schorey, assistant professor
Edward H. Hinchcliffe, assistant professor
Kevin T. Vaughan, assistant professor
Computer Science and Engineering
Danny Chen, Rooney associate professor
Jesus A. Izaguirre, assistant professor
Gregory R. Madey, associate professor
Chemical Engineering
Andre F. Palmer, assistant professor
Chemistry and Biochemistry
Brian M. Baker, assistant professor
Holly V. Goodson, assistant professor
Mathematics
Mark S. Alber, professor
Bei Hu, professor
Physics
Albert-László Barabási, Emil T. Hofman professor
James A. Glazier, associate professor
Gerald L. Jones, professor
FACILITIES
Laboratory for Computational Life Sciences
http://www.nd.edu/~icsb |
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