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."
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."
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."
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."
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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