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Discoveries
Research Briefs
Affected by CF
DMS scientists have identified a gene named
cif that, with its corresponding protein, may
contribute to cystic fibrosis (CF). The group
previously reported that Pseudomonas aeruginosa,
a pathogen that often colonizes CF-affected
lungs, secretes a protein (the one
just identified) that may contribute to
the disease. Writing in Infection and Immunity,
principal investigator George
O'Toole, Ph.D., and colleagues "demonstrate
that the cif gene is expressed in the cystic fibrosis
lung," and propose a model by which
P. aeruginosa colonizes a CF lung.
Bone of contention
A hip fracture increases an elderly person's
risk of dying, but only in the first six months
after the injury, a DMS study concluded. After
six months, pre-fracture frailty and illness
are more important predictors of death than
the fracture itself or age, sex, race, or socioeconomic
status. "Our study indicates that
fracture prevention may be of limited
benefit in extending overall life
expectancy," wrote Anna Tosteson,
Sc.D., and colleagues in Osteoporosis International.
Since "hip fracture is one of the most
highly visible and devastating consequences
of osteoporosis," they note, the finding has
implications for the "economic value" of
"costly new osteoporosis treatments."
Breast stroke
Premenopausal women with very dense
breasts are twice as likely to develop ductal
carcinoma in situ (DCIS), an early form of
breast cancer, as premenopausal women with
scattered-density breasts. That's according
to a DMS-led study of data in the
New Hampshire and Vermont mammography
registries. "Our study," wrote
the investigators in Cancer Causes and
Control, "is the first prospective assessment
of breast density in relation to risk of
DCIS, and the only study to separately examine
the influence of density in premenopausal
and postmenopausal women."
Chemobrain question
A study in rats has shed light on "chemobrain"—the mild cognitive impairment that
many cancer patients feel after chemotherapy
treatment. Working with DMS faculty,
Dartmouth College grad student Jill
MacLeod examined the effects of a
standard breast cancer chemo regimen
on learning and memory in rats. She
found that rats treated with cyclophosphamide
and doxorubicin had difficulty remembering
some types of information. Her results,
published in Behavioural Brain Research, suggest
the drugs "may have toxic effects on the
hippocampus" and cause "specific learning
deficits shortly after treatment has ended."
Watery worry
Arsenic—at levels commonly found in contaminated
wells in the United States—can
interfere with numerous important biological
pathways. Molecular epidemiologist Angeline
Andrew, Ph.D., and other Dartmouth
investigators observed in mice that arsenic
altered signaling pathways important in
angiogenesis, lipid metabolism, oxygen
transport, apoptosis, the cell cycle, and
immune responses. Publishing in Toxicological
Sciences, Andrew and her colleagues
expect that their research "will help guide investigations
into mechanisms of arsenic's
health effects and clarify the threshold for biologic
effects and potential disease risk."
Complex matters
A team of DMS biochemists recently took
some of the mystery out of how organelle
membranes merge within a cell. Membrane
merging is essential for moving and sorting
proteins and has been known to include a
protein complex called SNAREs, as
well as the Rab family of proteins.
By detailing how SNAREs and
Rabs interact to drivemembranemergers and
to protect organelles from lysis, the paper
earned principal investigator William Wickner,
M.D., and his coauthors "feature article"
placement in the August 21 Proceedings of
the National Academy of Sciences.
DMS's Henry Bernstein, D.O., published in the journal Pediatrics the first prospective study of post-childbirth discharge decisions; 17% of patients were deemed not ready to go home.
Dartmouth transplant surgeon David Axelrod, M.D., analyzed the cost of transplanting "marginal" versus "ideal" donated livers. On average, marginal organs cost $84,000 more.
DMS's Department of Genetics, according to data from the Association of American Medical Colleges, ranks in the top 10% nationwide in terms of grant funding per faculty member.
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