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For
a world of emerging diseases, a revived program in microbiology
Three decades
ago, it seemed that modern medicine had virtually eliminated
many infectious diseases. Armed with antibiotics, vaccines and
a sense of victory in the war against microbes, medical schools
began to look at the discipline of microbiology in a different
light, and in 1972 Yale joined others in disbanding its department.
By the 1980s,
however, such deadly microbes as HIV, Ebola, Marburg, and Legionnaires’
disease surfaced to remind physicians that infectious diseases
were still alive and represented very real public health threats.
Moreover, some of the older pathogens had developed resistance
to drugs that had once been effective.
With this in
mind, faculty at the School of Medicine began work several years
ago to reestablish a formal program in the microbiology of infectious
disease. In July, those plans came to fruition with the appointment
of Jorge E. Galan, D.V.M., Ph.D., as the first chair of a new
Section of Microbial Pathogenesis. Support for the program came
from The Esther A. and Joseph Klingenstein Fund Inc. and the
Lucille P. Markey Charitable Trust.
“Times
change,” Dr. Galan said in an interview. “With the
new emerging infections, and with others making a comeback as
you would expect in any kind of biological cycle, there is a
new interest in infectious disease. I hope that interest is here
to stay.”
Microbial Pathogenesis
is the fifth autonomous section at the medical school and the
first created since 1988, when the Section of Immunobiology was
founded. Dr. Galan and his colleagues will focus their research
on the interactions that occur between pathogens and their hosts,
an increasingly rich and fruitful area of research. The section
also will become the academic and administrative home to a four-year-old
graduate track in microbiology now administered as part of the
Biomedical and Biological Sciences Program. The microbiology
track, which has 25 students this year, was created in anticipation
of the new section’s founding.
Dr. Galan and
his two colleagues in the section, Craig R. Roy, Ph.D., and Norma
W. Andrews, Ph.D., will carry out research on bacteria and parasites
and teach first- and second-year medical students. In addition,
the new chair plans to apply for a training grant to further
strengthen the microbiology track. Over the next few years, the
section is expected to grow to a total of six faculty members.
Caroline W.
Slayman, Ph.D., deputy dean for academic and scientific affairs
and chair of the task force that recommended the section, said
Dr. Galan was selected as chair because he is one of the world’s
leading researchers in the area of bacterial pathogens. “His
selection,” she said, “reflects the feeling of the
search committee that the real challenge is to work with pathogens
and study their interactions with their host cells.”
Keith A. Joiner,
M.D., professor of medicine and epidemiology, and a member of
the search committee, said Dr. Galan was recruited not only for
his work in bacterial pathogenesis, but also for his broad scientific
perspective, which will facilitate interactions with colleagues
in related fields such as cell biology, immunology, epidemiology,
infectious diseases and structural biology.
Dr. Andrews,
a faculty member in cell biology for the past four years, is
an authority on parasite-host interactions. Dr. Roy worked in
the same department as Dr. Galan at the State University of New
York at Stony Brook and was recruited to Yale to continue his
research on bacterial pathogenesis. Using Legionella pneumophila
as a medium, Dr. Roy studies mechanisms by which bacteria subvert
the normal functioning of human cells.
Dr. Galan believes
the idea that infectious diseases will one day be completely
eradicated is mistaken. “We will never, ever be able to
conquer infectious diseases,” he said. “We may learn
how to deal with a given pathogen but eventually other pathogens
will emerge. This is going to be a battle forever, there is no
question about it.” |
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Dissecting
the body with
the click of a mouse
Exploring the
depths of the human body is one of the hallmarks of the first
year of medical school. Through new computer software that offers
three-dimensional views of human anatomy, Yale students can now
dissect the body with the click of a mouse.
The new computer
teaching tool provides a complement to standard anatomy training
in the cadaver lab. Based on data from the National Library of
Medicine’s Visible Human Project, the software called the
Divisible Human allows students to view three different images
of the same body part simultaneously on a computer monitor. “This
is the first time that the Visible Human data has been available
in a form where students can actually manipulate and learn something
from it,” said William B. Stewart, Ph.D., associate professor
of surgery and section chief for anatomy and experimental surgery.
“What one can do is pick a plane and dissect into it. From
the anatomist’s point of view one of the most critical skills
you can teach students is how to reason and problem solve in
three dimensions.”
“The difference
in technology between moving from plane to plane and true animation
is extraordinary,” said John A. Paton, Ph.D., director of
academic computing at the school, describing the software developed
by Shane Dunne, Ph.D., a computer scientist from Kingston, Ontario.
“It means people can explore much more effectively than
they could before.” Adds Dr. Stewart “This is the way
that in the future they will be viewing radiology.” Dr.
Stewart is the first anatomy instructor in the country to use
the software and also has developed laboratory exercises to use
with it.
The new software
allows access to cross-sectional slice images of the anatomy,
at any orientation and in any combination. Although each slice
image is two-dimensional, the program presents multiple slices
in a three-dimensional format which clearly illustrates relative
position and orientation. Other commercial and academic software
using the visible human allow access only in two dimensions,
in standard orientations and much more slowly. And while most
programs tend to be difficult to learn, Dr. Dunne says his software
is “as quick and easy to use as a video game.” |
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Brain
surgery, without
opening the skull
For decades
neurosurgeons have treated diseases of the brain by beaming radiation
inside the skull, sidestepping the need to cut through scalp
and bone. The arrival of a 30-ton gamma knife at Yale in July
enables this intricate form of brain surgery with a previously
unmatched precision.
The Swedish-made
gamma knife beams up to 201 gamma rays around a single point
in the brain, letting the radiation accumulate on that point
without disturbing surrounding tissue. Individually, the rays
do no harm, but when they converge on their target the concentration
of radiation can destroy lesions, tumors and blood vessel malformations.
Based at the Temple Medical Center, the $2.9 million instrument
is the first of its kind in Connecticut and one of
only 35 in the whole country.
Treatment with
the gamma knife requires placing the patient in a fixed frame
that keeps the head absolutely steady during the procedure. Once
ready, the patient lies inside the gamma knife for between 15
minutes and two hours. The radiation treatment is accurate to
within .3 millimeters. After the treatment the radiation can
take days or weeks to achieve the desired effect.
Because it is
more accurate and easier to use, the gamma knife has largely
replaced its precursor, the linear accelerator which beams X-rays
into the brain. The linear accelerator was accurate to within
plus or minus 1 millimeter and could take hours to do what the
gamma knife does in minutes.
“With the
gamma knife,” said Alain deLotbinière, M.D., associate
clinical professor of neurosurgery and director of radiosurgery
at Yale-New Haven Hospital and of the Gamma Knife Surgery Center,
“we can destroy abnormal tissue very precisely without damaging
adjacent normal brain tissue and without subjecting patients
to the trauma of surgery. The gamma knife enables us to destroy
tumors in areas of the brain that are inaccessible to the surgeon’s
scalpel or so close to vital structures, such as the optic nerve,
that surgery could irreparably harm normal brain tissue.” |
