July 21, 2011, 9:59 PM CT
Help women fight infections during pregnancy
A normal but concerning consequence of pregnancy is the fact that pregnant women are more susceptible to infection. University of Minnesota Medical School scientists have identified the underlying mechanisms for this physiologic immune suppression that may lead to new therapies to help ward off infections during pregnancy.
In pregnancy, immune system suppressing cells (called regulatory T cells) increase in number to protect the baby from attack by the mother's immune system. Because these cells are busy protecting the developing baby, pregnant women aren't able to curb off infections caused by common but potentially serious disease-causing bacteria, such as Listeria
Using a mouse pregnancy model, Dr. Sing Sing Way, an Assistant Professor in the Departments of Pediatrics and Microbiology, and colleagues from the Center for Infectious Disease and Microbiology Translational Research have developed a method to dissociate the beneficial and detrimental impacts of maternal regulatory T cells.
Specifically, when the immune suppressive molecule IL-10 is removed from regulatory T cells, mice were able to more efficiently combat infection against prenatal pathogens. Importantly, removing the IL-10 molecule did not have any negative impact on the outcome of the pregnancy.........
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July 20, 2011, 10:36 PM CT
Keys to Melanoma Progression
Lei Xu, Liquan Yang, and Sonali Mohanty in the laboratory
Melanoma is devastating on a number of fronts: rates are rising dramatically among young people, it is deadly if not caught early, and from a biological standpoint, the disease tends to adapt to even the most modern therapies, known as VEGF inhibitors. University of Rochester researchers, however, made an important discovery about proteins that underlie and stimulate the disease, opening the door for a more targeted therapy in the future.
This month in the journal Cancer Research, Lei Xu, Ph.D., assistant professor of Biomedical Genetics at the University of Rochester Medical Center, proposed that a receptor called GPR56 - which mostly has been studied in the context of brain formation -- has an important role in cancer progression.
Xu and his colleagues believe they are the first to show the biological mechanisms of how GPR56 relates to the growth and spread of melanoma, and might even be responsible for triggering one of the lethal processes of cancer progression, known as angiogenesis.
"We are very excited about this work because not only did we find an important new factor in melanoma, but we have also shown the signaling pathways through which these G-protein coupled receptors could impede cancer cell growth," Xu said. "Perturbing these pathways could potentially lead to more effective therapys for cancerous melanoma".........
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July 20, 2011, 10:31 PM CT
Fast prediction of axon behavior
Scientists at Case Western Reserve University have developed a computer modeling method to accurately predict how a peripheral nerve axon responds to electrical stimuli, slashing the complex work from an inhibitory weeks-long process to just a few seconds.
The method, which enables efficient assessment of a nerve's response to millions of electrode designs, is an integral step toward building more accurate and capable electrodes to stimulate nerves and thereby enable people with paralysis or amputated limbs better control of movement.
To increase the accuracy of the results, the scientists included a key parameter overlooked in past mathematical approaches that were equally fast, but inaccurate. With the new techniques, electrode design can be optimized using advanced algorithms based on natural genetics.
An explanation of the work, which the team hopes others in the field will freely use, and a second method that was simpler and faster but proved less effective, are now available online in the Journal of Neural Engineering
"We believe this will allow the next generation of computer-aided development of electrodes," said Dustin Tyler, associate professor of biomedical engineering at Case School of Engineering and senior author of the paper.........
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July 20, 2011, 10:18 PM CT
Evolution provides clue to blood clotting
The building blocks of von Willebrand Factor remain separate at the slightly basic pH of 7.4 (left). In a more acidic environment (right), the VWF building blocks self-assemble into long chains and form the protein's signature helical tubules. This shape is vital to blood clotting. When VWF in the blood finds sites of injury, its helical tube unfurls to catch platelets and form blood clots.
A simple cut to the skin unleashes a complex cascade of chemistry to stem the flow of blood. Now, researchers at Washington University School of Medicine in St. Louis have used evolutionary clues to reveal how a key clotting protein assembles. The finding sheds new light on common bleeding disorders.
The long tube-shaped protein with a vital role in blood clotting is called von Willebrand Factor (VWF). Made in cells that form the inner lining of blood vessels, VWF circulates in the blood seeking out sites of injury. When it finds them, its helical tube unfurls to catch platelets and form blood clots. Defects in VWF cause von Willebrand Disease, the most common inherited bleeding disorder in humans.
"The challenge for the cell is how to build this massive protein without clogging the machinery," says J. Evan Sadler, MD, PhD, professor of medicine and senior author of the study published in July in the Journal of Biological Chemistry. "The cell has solved this problem by making the assembly of von Willebrand Factor dependent on its location in the cell".
And VWF knows its location in a cell because pH, a measure of how acidic or basic a liquid is, varies from one cellular structure to the next. On a scale of 0 to 14, pure water has a neutral pH of about 7; human blood is slightly basic with a pH of 7.4.........
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July 18, 2011, 8:25 AM CT
'Love your body' to lose weight
Almost a quarter of men and women in England and over a third of adults in America are obese. Obesity increases the risk of diabetes and heart disease and can significantly shorten a person's life expectancy. New research published by BioMed Central's open access journal International Journal of Behavioral Nutrition and Physical Activity
shows that improving body image can enhance the effectiveness of weight loss programs based on diet and exercise.
Scientists from the Technical University of Lisbon and Bangor University enrolled overweight and obese women on a year-long weight loss program. Half the women were given general health information about good nutrition, stress management, and the importance of looking after yourself. The other half attended 30 weekly group sessions (the intervention plan) where issues such as exercise, emotional eating, improving body image and the recognition of, and how to overcome, personal barriers to weight loss and lapses from the diet were discussed.
On the behavioral intervention plan women observed that the way they thought about their body improved and that concerns about body shape and size were reduced. In comparison to the control group they were better able to self-regulate their eating and they lost much more weight, losing on average 7% of their starting weight in comparison to less than 2% for the control group.........
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July 18, 2011, 8:21 AM CT
Trastuzumab and chemotherapy improves survival
The use of trastuzumab, chemotherapy and surgery among women with HER2-positive metastatic breast cancer significantly improved survival from the time central nervous system metastases were diagnosed.
Based on these study results, lead researcher Adam Brufsky, M.D., Ph.D., said, "We clearly now know that these women should get trastuzumab and potentially chemotherapy, even if cancer spreads to the brain."
"Women with HER2-positive breast cancer have a reasonable chance of living a long time with their disease, and they should be given aggressive treatment where appropriate," added Brufsky, professor of medicine and associate director of clinical investigation at the University of Pittsburgh Cancer Institute.
Ten to 16 percent of women with advanced breast cancer develop central nervous system metastases, the scientists wrote in their study, published in Clinical Cancer Research
, a journal of the American Association for Cancer Research.
Brufsky and his colleagues used data from the registHER study to evaluate the incidence, potential risk factors and outcomes for patients with HER2-positive breast cancer. They reviewed how patients with HER2-positive breast cancer develop brain metastases, and followed them to examine what happens thereafter.........
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July 18, 2011, 8:18 AM CT
Genetic mutations that lead to colon cancer
Scientists at UT Southwestern Medical Center say there are at least 70 genetic mutations involved in the formation of colon cancer, far more than researchers previously thought.
Based on the study, reported in the July 2011 Cancer Research (Priority Reports), scientists are suggesting a new approach to colon cancer therapys targeting multiple genes and pathways simultaneously. Current cancer therapys target just one or two known cancer-driver genes believing this would be beneficial to patients. While patients may get transient tumor burden reduction, almost universally tumor growth returns.
The UT Southwestern research contradicts prior thinking that only a few mutated genes are important in the development of malignant tumors.
"The ways we've been treating patients up to now is to just go after one target when we should be going after three to four different pathways simultaneously," said Dr. Jerry W. Shay, vice chairman and professor of cell biology at UT Southwestern.
Under the old model, researchers believed there were 151 candidate genes and that mutations in just eight to 15 of them would lead to cancer. There were 700 other genes classified as passenger genes whose mutations were incidental to cancer growth.
"Those numbers are dead wrong," Dr. Shay said. As per UT Southwestern's research, there are 65 candidate genes and at least five passenger genes whose mutations play significant roles in cancer development. Inactivating the function of any of these tumor-suppressing genes led to a key step in cancer development called anchorage-independent growth, meaning cells piled up on top of each other rather than aligning neatly.........
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July 5, 2011, 8:38 PM CT
Folate intake may reduce colorectal cancer risk
A newly released study finds high folate intake is linked to a reduced risk of colorectal cancer, a finding consistent with the findings of most prior epidemiologic studies. The study is reassuring, as prior recent evidence has suggested that consumption of very high levels of folate through supplements and from folate-fortified diet may increase risk of some cancers. Nonetheless, the potential importance of folate in colorectal cancer prevention remains in question because at least one other study found folate supplementation had no effect on recurrence of colorectal adenomas, precursors to colorectal cancer.
The study appears in Gastroenterology,
and is the first to look at the association of folate with colorectal cancer risk with follow-up entirely after the required fortification of the U.S. diet with folate. It also is the first to distinguish between the forms of folate found naturally in forms and folic acid, the form used for fortification and in supplements.
A research team led by Victoria Stevens, Ph.D., strategic director of laboratory services at the American Cancer Society, investigated the association between folate intake and colorectal cancer among 99,523 participants in the Cancer Prevention Study II Nutrition Cohort. A total of 1,023 participants were diagnosed with colorectal cancer between 1999 and 2007, a period entirely after folate fortification began. Neither higher nor lower risk was observed during the first two years of follow-up (1999 to 2001), but during 2002 to 2007, high folate intake was linked to a reduced risk of colorectal cancer.........
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July 5, 2011, 8:29 PM CT
Distract yourself or think it over?
A big part of coping with life is having a flexible reaction to the ups and downs. Now, a study which will be published in an upcoming issue of Psychological Science,
a journal of the Association for Psychological Science, finds that people choose to respond differently depending on how intense an emotion is. When confronted with high-intensity negative emotions, they tend to choose to turn their attention away, but with something lower-intensity, they tend to think it over and neutralize the feeling that way.
Emotions are useful for example, fear tells your body to get ready to escape or fight in a dangerous situation. But emotions can also become problematic for example, for people with depression who can't stop thinking about negative thoughts, says Gal Sheppes of Stanford University, who cowrote the study with Stanford colleagues Gaurav Suri and James J. Gross, and Susanne Scheibe of the University of Groningen. "Luckily, our emotions can be adjusted in various ways," he says.
Sheppes and colleagues studied two main ways that people modulate their emotions; by distracting themselves or by reappraising the situation. For example, if you're in the waiting room at the dentist, you might distract yourself from the upcoming unpleasantness by reading about celebrity breakups "Maybe that's why the magazines are there in the first place," Sheppes says or you might talk yourself through it: "I say, ok, I have to undergo this root canal, but it will make my health better, and it will pass, and I've done worse things, and I can remind myself that I'm ok".........
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July 5, 2011, 8:17 PM CT
Biomechanics of ovarian cells
Masoud Agah directs Virginia Tech's Microelectromechanical Systems Laboratory or VT MEMS Lab. The lab resides within the Bradley Department of Electrical and Computer Engineering and is affiliated with the Department of Mechanical Engineering and the MicrON Research Group. Some of its recent work includes: the development of micro gas analyzers for environmental and health-care applications, and biochips for cancer diagnosis and cancer treatment monitoring.
Credit: Virginia Tech Photo
Using ovarian surface epithelial cells from mice, scientists from Virginia Tech have released findings from a study that they believe will help in cancer risk evaluation, cancer diagnosis, and therapy efficiency in a technical journal: Nanomedicine
By studying the viscoelastic properties of the ovarian cells of mice, they were able to identify differences between early stages of ovary cancer and more advanced and aggressive phenotypes.
Their studies showed a mouse's ovarian cells are stiffer and more viscous when they are benign. Increases in cell deformation "directly correlates with the progression from a non-tumor non-malignant cell to a cancerous one that can produce tumors and metastases in mice," said Masoud Agah, director of Virginia Tech's Microelectromechanical Systems (MEMS) Laboratory http://www.ece.vt.edu/mems/ and the lead investigator on the study.
Their findings are consistent with a University of California at Los Angeles study that reported lung, breast, and pancreatic metastatic cells are 70 percent softer than non-malignant cells. http://www.nature.com/nnano/journal/v2/n12/full/nnano.2007.388.html.
The findings also support Agah group's prior reports on elastic properties of breast cell lines. The digital object identifiers to find the studies on the web are: doi:10.1016/j.biomaterials.2010.05.023.........
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