December 18, 2009, 8:22 AM CT
Protein that causes cystic fibrosis
Jeng-Haur Chen is a postdoctoral researcher at the University of Iowa's medical college and the lead author on a paper to be published in the Dec. 18 issue of the Journal of Biological Chemistry.
Credit: Handout photo
A team of scientists studying the protein that, when defective or absent, causes cystic fibrosis (CF) has made an important discovery about how that protein is normally controlled and under what circumstances it might go awry.
"Understanding the regulation of salt transport in normal cells is critical for the development of new therapies for diseases, like CF, that disrupt salt movements across cell borders," said Jeng-Haur Chen, a postdoctoral researcher at the University of Iowa Carver College of Medicine and the main author on a paper to be reported in the Dec. 18 issue of the Journal of Biological Chemistry
Cystic fibrosis is an inherited chronic disease that affects a number of organs, especially the lungs and digestive system. CF patients carry a defective gene that disables or destroys its protein product, which normally regulates the transport of salt across cell borders. As a result, the body produces thick mucus that blocks its ducts and tubes.
Blockage of air passageways causes chronic cough and lung infection; blockage of the pancreas prevents enzyme delivery to the intestine to break down food; and blockage in the intestine prevents food absorption.
About 70,000 people worldwide have the disease, the majority of whom are children and young adults.........
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December 17, 2009, 8:06 AM CT
Michelangelos make smart lovers
Is that really Bob? You've seen him hundreds of mornings for the last 10 years at local coffee shops. Since he started dating Sara, he looks you in the eye -- and smiles. Sara takes every opportunity to let coffee shop cronies know that Bob is her guy and to gush about how funny he is. And he is. Who knew?
Think of Sara like Michelangelo chipping away at a block of marble to release the ideal figure slumbering within.
A new international review of seven papers on "the Michelangelo phenomenon" shows that when close partners affirm and support each other's ideal selves, they and the relationship benefit greatly.
"To the degree that the sculpting process has gone well, that you have helped mold me toward my ideal self, the relationship functions better and both partners are happier. And over the long term, I more or less come to reflect what my partner sees and elicits from me," said Eli Finkel, associate professor of psychology in the Weinberg College of Arts and Sciences at Northwestern University.
Finkel co-authored the review with Caryl E. Rusbult, Vrije Universiteit Amsterdam, and Madoka Kumashiro, Goldsmiths, University of London. "The Michelangelo Phenomenon" appears in the recent issue of the journal Current Directions in Psychological Science
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December 15, 2009, 11:37 PM CT
Terminal cancer patients' spiritual needs
In a newly released study of terminally ill cancer patients, scientists at Dana-Farber Cancer Institute found support of patients' spiritual needs by the medical team is linked to greater use of hospice, less aggressive care, and greater quality of life near death. The study is published by the Journal of Clinical Oncology
on its web site and later will be published in a print edition.
"Recent research has shown that religion and spirituality are major sources of comfort and support for patients confronting advanced disease," says the study's senior author, Tracy Balboni, MD, MPH, of Dana-Farber. "Our findings indicate that patients whose spiritual needs are supported by their medical team, including doctors, nurses and chaplains, have better quality of life near death and receive less aggressive medical care at the end of life".
The study involved 343 incurable cancer patients at hospital and cancer centers around the country. Participants were interviewed about their means of coping with their illness, the degree to which their spiritual needs were met by the medical team and their preferences regarding end-of-life therapy. Investigators then tracked each patient's course of care during the remainder of his or her life.
The scientists observed that patients whose spiritual needs were largely or completely supported by the medical team were likely to transition to hospice care at the end of life. Additionally, among patients relying on their religious beliefs to cope with their illness, spiritual support reduced their risk of receiving aggressive medical interventions at the end of life. Support of patients' spiritual needs by the medical team was also linked to better patient well-being at the end of life, with scores on average being 28 percent higher among those receiving spiritual support.........
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December 15, 2009, 11:36 PM CT
Chip capable of growing cardiac tissue
Johns Hopkins researchers developed this chip to culture heart cells that more closely resemble natural cardiac tissue. Photo: Will Kirk/homewoodphoto.jhu.edu .
Johns Hopkins biomedical engineers, working with colleagues in Korea, have produced a laboratory chip with nanoscopic grooves and ridges capable of growing cardiac tissue that more closely resembles natural heart muscle. Surprisingly, heart cells cultured in this way used a "nanosense" to collect instructions for growth and function solely from the physical patterns on the nanotextured chip and did not require any special chemical cues to steer the tissue development in distinct ways. The researchers say this tool could be used to design new therapies or diagnostic tests for cardiac disease.
The device and experiments using it were described in this week's online Early Edition of Proceedings of the National Academy of Sciences. The work, a collaboration with Seoul National University, represents an important advance for scientists who grow cells in the lab to learn more about cardiac disorders and possible remedies.
"Heart muscle cells grown on the smooth surface of a Petri dish, would possess some, but never all, of the same physiological characteristics of an actual heart in a living organism," said Andre Levchenko, a Johns Hopkins associate professor of biomedical engineering at the Whiting School of Engineering. "That's because heart muscle cells-cardiomyocytes-take cues from the highly structured extracellular matrix or ECM, which is a scaffold made of fibers that supports all tissue growth in mammals. These cues from the ECM influence tissue structure and function, but when you grow cells on a smooth surface in the lab, the physical signals can be missing. To address this, we developed a chip whose surface and softness mimic the ECM. The result was lab-grown heart tissue that more closely resembles the real thing".........
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December 15, 2009, 11:27 PM CT
Decoding memory-forming brain cell conversations
The conversations neurons have as they form and recall memories have been decoded by Medical College of Georgia scientists.
The breakthrough in recognizing in real time the formation and recollection of a memory opens the door to objective, thorough memory studies and eventually better therapies, said Dr. Joe Tsien, neuroscientist and co-director of MCG's Brain & Behavior Discovery Institute. He is corresponding author on the study published Dec. 16 in PLoS ONE
"It's a beginning, a first glimpse of a memory," Dr. Tsien said. "For the first time it gives us the ability to look at the brain dynamic and tell what kind of memory is formed, what are the components of the memory and how the memory is retrieved at the network level." The finding could help pinpoint at what stage memory formation is flawed and whether drugs are improving it.
For their studies, MCG researchers combined new technology and computational methods with century-old Pavlovian conditioning.
In the memory center of the brain, they used 128 electrodes capable of monitoring a handful of neurons each to simultaneously record the conversations of 200 to 300 neurons as mice learned to associate a certain tone with a mild foot shock 20 seconds later.........
Posted by: Daniel Read more Source
December 10, 2009, 11:12 PM CT
A Novel Model of Skin Cancer
Researchers at the University of Pennsylvania School of Medicine have developed a new model of skin cancer based on the knowledge that a common cancer-related molecule called Src kinase is activated in human skin-cancer samples.
"Our prior work demonstrated that Src kinases are activated in human squamous cell carcinomas of the skin. We modeled these observations by increasing the expression of the gene Fyn, a member of Src family of proteins, in mouse skin," explains senior author John T. Seykora MD, PhD, assistant professor of Dermatology. In addition, previous work by the Seykora lab on a related protein called Srcasm, discovered by him in 2002, suggested that Srcasm may function as an anti-oncogene, a molecule that keeps others in check in order to control cell growth.
In this proof-of-principle study, published this month in Cancer Research, the authors observed that genetically engineered mice expressing a K14-Fyn transgene develop premalignant lesions and invasive squamous cell carcinomas (SCCs) spontaneously in 5 to 8 weeks. Skin SCCs are the second most common form of cancer, with greater than 250,000 cases annually in the US, leading to approximately 2,500 deaths.
This study demonstrates that Fyn is a potent oncogene in skin. When Srcasm levels are raised in the mouse skin cancer model, tumor formation is dramatically inhibited showing that Srcasm functions as an anti-oncogene.........
Posted by: George Read more Source
December 10, 2009, 11:09 PM CT
Biological Route for Swine Flu to Human
A mutation in the H1N1 influenza A virus, termed the SR polymorphism, enhanced replication of the virus in humans. (Image courtesy of NIGMS)
A new biological pathway by which the H1N1 flu virus can make the jump from swine to humans has been discovered by scientists with the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California, Berkeley. Early test results indicate that a heretofore unknown mutation in one of the H1N1 genes may have played an important role in transmitting the virus into humans.
"Transmission of influenza viruses into the human population requires surmounting biological barriers to cross-species infection," says biochemist Jennifer Doudna, the principal investigator for this research. "We have identified an adaptive mutation in the swine origin H1N1 influenza A virus - a pair of amino acid variants termed the 'SR polymorphism' - that enhance replication, and potentially pathogenesis of the virus in humans".
Doudna, an authority on RNA molecular structures, holds joint appointments with Berkeley Lab's Physical Biosciences Division, and UC Berkeley's Department of Molecular and Cell Biology and Department of Chemistry. She's also an investigator with the Howard Hughes Medical Institute (HHMI). She and Andrew Mehle, a post-doctoral fellow in her research group, have published a paper on this research in the Proceedings of the National Academy of Sciences (PNAS) titled: Adaptive strategies of the influenza virus polymerase for replication in humans".........
Posted by: Mark Read more Source
December 10, 2009, 8:13 AM CT
How calorie-restricted diets fight obesity
Fruits and vegetables are a key part of calorie-restricted diets, which may increase longevity.
Credit: Wikimedia Commons, Eric Hunt
Researchers searching for the secrets of how calorie-restricted diets increase longevity are reporting discovery of proteins in the fat cells of human volunteers that change as pounds drop off. The proteins could become markers for monitoring or boosting the effectiveness of calorie-restricted diets the only scientifically proven way of extending life span in animals. Their study appears online in ACS' Journal of Proteome Research
Edwin Mariman and his colleagues note that researchers have long known that sharply restricting intake of calories while maintaining good nutrition makes animals live longer and stay healthier. Recent studies suggest that people may gain similar benefits. But researchers know little about how these diets work in humans, especially their effects on cells that store fat.
The newly released study focused on proteins in abdominal subcutaneous fat cells from a group of overweight people before and after they went on a five-week-long calorie-restricted diet. The volunteers each lost an average of 21 pounds. Researchers identified changes in the levels of 6 proteins as the volunteers shed pounds, including proteins that tell the body to store fat. These proteins could serve as important markers for improving or tracking the effectiveness of therapies involving calorie-restricted diets, they say.........
Posted by: JoAnn Read more Source
December 10, 2009, 7:51 AM CT
Secrets to new epilepsy treatments
A team of researchers from The University of Alabama used worms to reel in information that they hope will lead to a greater understanding of cellular mechanisms that appears to be exploited to treat epilepsy. In a new research report in the journal GENETICS
(http://www.genetics.org), the scientists explain how the transparent roundworm, C. elegans
, helped them identify key "molecular switches" that control the transport of a molecule (gamma-aminobutyric acid or "GABA") that if manipulated within our cells, might prevent the onset of seizures.
"It is our hope that this work serves to accelerate the path toward the identification of genetic factors that cause a susceptibility to epilepsy," said Guy A. Caldwell, Ph.D., co-author of the study from the Department of Biological Sciences at The University of Alabama in Tuscaloosa. "Simultaneously, this work has the potential to uncover new avenues toward therapeutic development to control or prevent seizures in the future."
To make this finding, the scientists conducted experiments involving drugs known to affect neuronal activity in combination with DNA mutations in genetic factors shared between C. elegans
and humans. Changes in the worm's neuronal activity led to repetitive convulsions thought to besimilar to those experienced in epilepsy. These convulsions were observed under a microscope, and videos of those events were used to evaluate the severity of the neuronal changes. At the same time, the scientists used a green fluorescent protein to "tag" or "label" the cellular locale and delivery of GABA in neurons. This tagging allowed the scientists to see the specific genetic factors that led to abnormal movement of GABA in neurons as they coincided with worm seizures and to make appropriate comparisons with worms from the control group.........
Posted by: Daniel Read more Source
December 9, 2009, 11:31 PM CT
Those weekend parties and obesity
The holidays can be challenging for even the most diligent dieters. But are weekends just as detrimental? Scientists at the University of Pittsburgh and Quinnipiac University in Hamden, Conn., observed that weekend eating patterns change significantly.
J. Jeffrey Inman, a University of Pittsburgh professor of marketing and associate dean for research in the Joseph M. Katz Graduate School of Business, and his coauthor, Adwait Khare, Quinnipiac University professor of marketing, studied two years' worth of data on consumers' eating behavior and observed that the quantity and quality of foods eaten during a meal and over the course of the day differs considerably on weekends and holidays.
Just as important as the daily caloric increase on weekends and holidays is the nutritional value of the food consumed, as per the research, which was reported in the Fall 2009 issue of the "Journal of Public Policy & Marketing." Labor Day barbeques and Thanksgiving Day feasts focus on family and friends bonding over tables laden with high-calorie foods. Because the quantity and quality of food consumed changes during these times, Inman suggests that the U.S. Department of Agriculture incorporate recommendations for holiday and weekend eating into its food pyramid guidelines.
Understanding eating patterns and knowing that a weekend can be just as dangerous to the diet as a holiday dinner arms consumers, doctors, and nutritionists with more knowledge to fight obesity, says Inman.........
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