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University of Washington School of Medicine
Online News
Vol. 11, No. 10
March 9, 2007
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To view an archived version of Online News on the UW Medicine Web site, visit:
http://www.uwmedicine.org/Global/NewsAndEvents/somnews/index.htm
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This week’s news:
* Individuals and populations differ in gene activity levels, not just genes, UW researchers find
* New mutant pore in sodium ion channel could explain type of periodic paralysis disorder
* Morayma Reyes named first recipient of recurring research award from Seattle-based law firm Perkins Coie
* Faculty in pulmonary and critical care honored by American Thoracic Society
* Medical students prepare for residency program Match Day, next Thursday, March 15
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INDIVIDUALS AND POPULATIONS DIFFER IN GENE ACTIVITY LEVELS
Much like how a person's genetic code differs from other individuals, the level at which those genes are activated in the body differs from one person to another, scientists have learned. And though some of those differences in gene activity are seen between different populations – Asians versus Europeans, for instance – more of those variations are due to individual-level factors, further obscuring the biological meaning of "race."
The findings could also have major implications for medical research, as differing levels of gene activity may affect one's susceptibility to developing a disease or one's response to a particular drug. The research was led by the UW's Joshua Akey, assistant professor of genome sciences, and John Storey, associate professor of genome sciences and of biostatistics. Their findings appear in the March issue of the American Journal of Human Genetics.
The researchers examined data on thousands of genes from 16 people of European and African ancestry, cataloging the variations between those individuals. They studied each person's levels of gene expression, which measures how much a particular gene is activated during the process of translating DNA into a substance called RNA, and from that into basic proteins. The more a gene is expressed, the more "messenger" RNA is produced, leading to formation of more proteins corresponding to that gene. If genetic information is like the computer hardware of the body, the researchers explain, gene expression is the software that tells the computer what to do.
Scientists have known for many years about genetic variation, in which individual letters in the genetic code change between individuals and between different populations. However, this study is one of the first to look at the variation in gene activity between individuals and populations.
The researchers found many differences in gene-expression levels, and that about 17 percent of those differences were due to population-level differences. The vast majority of the gene-expression variation was due to random differences between individuals, and was not tied to ancestral population or biological "race."
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NEW LEAK IN ION CHANNELS MAY EXPLAIN TYPE OF PERIODIC PARALYSIS DISORDER
A mutation in the sodium ion channel in skeletal muscle cells creates a new mutant pore that lets ions leak into cells through the voltage sensor of this channel, UW researchers have found. That ion leakage is thought to be responsible for unexplained aspects of periodic paralysis syndromes, and could also be involved in inherited forms of cardiac arrhythmia, epilepsy, ataxia, and migraine headaches. The findings appear in the March 1 issue of the journal Nature.
Ion channels are proteins that initiate and control electrical impulses across cell membranes in muscles and other kinds of tissue. The electrical impulses generated by ion channels initiate many important processes, like the contraction of a muscle cell or the firing of a neuron.
People with periodic paralysis diseases have inherited malfunctions in their ion channels that prevent normal generation of electrical impulses in skeletal muscle cells, leaving the muscles unable to contract. Previous research showed that these diseases are usually caused by impaired regulation of ion flow through the normal central pore of the sodium ion channel. However, this well-established disease mechanism does not explain the loss of muscle contraction in hypokalemic periodic paralysis, a specific form of episodic paralysis accompanied by low potassium concentration in the blood stream.
The UW researchers studied these disease mutations in frog egg cells, which are unusually large cells that make it easy for scientists to detect very small changes in electrical impulses. They found that the disease mutations in hypokalemic periodic paralysis cause the formation of a mutant pore in an unexpected area of the ion channel, in one of the voltage sensors. Ions leaking into the cell through the mutant pore could be detected as a small electrical current in the frog egg cells. This abnormal leakage is likely responsible for many of the unexplained adverse effects of this periodic paralysis disorder. The new results point the way to potential therapeutic approaches for this form of periodic paralysis.
The research team included Stanislav Sokolov, senior fellow in pharmacology; Todd Scheuer, research associate professor of pharmacology; and William Catterall, professor and chair of pharmacology. Their work was supported by research grants from the Muscular Dystrophy Association and the National Institutes of Health.
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MORAYMA REYES RECEIVES RESEARCH AWARD FROM PERKINS COIE LAW FIRM
Morayma Reyes, assistant professor of pathology and laboratory medicine, has received a $20,000 Award for Discovery from Seattle-based law firm Perkins Coie. The award will fund a research project to isolate and identify stem cells to regenerate heart tissue.
The award is part of a five-year commitment from Perkins Coie to support translational medicine research at the UW Medicine South Lake Union research hub. The firm will award $20,000 each year, until 2011, to support a new project to generate data that could be used as a basis for a larger research program supported by the National Institutes of Health or other funding agencies.
Reyes and her team will use the award for a pilot study to explore whether cardiac muscle contains multi-potent adult progenitor cells (MAPC) or MAPC-like cells. These cells may be more suitable than embryonic stem cells for regenerating heart tissue. The long-term goal of the project is to use the cells to treat heart attacks and other forms of cardiovascular disease.
Perkins Coie is an international firm with more than 600 attorneys in 15 offices across the United States and in China.
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FACULTY HONORED BY AMERICAN THORACIC SOCIETY
Two UW faculty members in the Division of Pulmonary and Critical Care Medicine have recently been honored by the American Thoracic Society.
Thomas R. Martin, professor and vice chair of medicine, will receive the William J. Martin II Distinguished Achievement Award from the society. The award honors innovative spirit, outstanding leadership skills, impressive public service, and passion for patients. Thomas R. Martin is the chief of medicine at the VA Puget Sound Health Care System and a former president of the thoracic society. He will receive the award at the society's international conference in May. He may be reached at trmartin@u.washington.edu
Gordon D. Rubenfeld, UW associate professor of medicine based at Harborview, will receive the Public Advisory Roundtable Excellence Award, which honors a person who has significantly improved the lives of patients with pulmonary illness. Rubenfeld studies outcomes of critical care in lung injury, chronic illness, and other areas. He may be reached at nodrog@u.washington.edu
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MEDICAL STUDENTS TO BE MATCHED WITH RESIDENCY PROGRAMS NEXT WEEK
Next Thursday, 152 UW graduating medical students will be matched with residency programs as part of the National Resident Match Program's "Match Day." The program coordinates students' preferences in sites and specialties with the needs and preferences of residency programs and medical facilities.
Each year, about 16,000 current U.S. medical students participate in the match program before moving on to complete their physician training. Another 18,000 independent applicants, including former medical school graduates and those who attended medical school abroad, also compete for residency positions.
On Thursday morning, the UW School of Medicine will hold a special ceremony in which students will receive their match results. Students and their families will begin gathering in the lobby of the Health Sciences Center at 8:30 a.m., and the match results will be distributed at 9 a.m. Light refreshments will be served.
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Online News is published by Health Sciences/UW Medicine News and Community Relations.
Justin Reedy, editor:
206-685-0382, jreedy@u.washington.edu
Online News is copyright 2007. All rights, including electronic redistribution, are reserved.
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