April 4, 2006, 10:27 PM CT
Walking At A Safer, Brisker Pace
Psychology experts wanting to help old people safely cross the street and otherwise ambulate around this busy world have found that from age 70 and up, safe walking may require solid "executive control" (which includes attention) and memory skills. For the old, slow gait is a significant risk factor for falls, a number of of which result in disabling fractures, loss of independence or even death. The finding may help explain why cognitive problems in old age, including dementia, are associated with falls. Cognitive tests could help doctors assess risk for falls; on the other hand, slow gait could alert them to check for cognitive impairment. The findings are in the recent issue of Neuropsychology, which is published by the American Psychological Association (APA).
Roee Holtzer, PhD, and colleagues conducted a cross-sectional study of 186 cognitively normal, community-dwelling adults aged 70 and older at New York City's Albert Einstein College of Medicine. Gait speed was tested with and without interference. In the interference conditions, participants had to walk while reciting alternate letters of the alphabet.
Performance on cognitive tests of executive control and memory, and to a lesser extent of verbal ability, predicted "gait velocity" (walking speed) tested without interference. For gait velocity tested with interference, only executive control and memory were predictive. Adding interference to the tests of gait allowed the scientists to better simulate the real world, in which walkers continually deal with distractions. The authors conclude that executive control and memory function are important when the individual has to walk in a busy environment.........
Posted by: JoAnn Permalink Source
April 4, 2006, 9:53 PM CT
Daughters Of Indian Immigrants Giving Birth To Small Babies
U.S.-born Asian-Indian women are more likely than their Mexican-American peers to deliver low birth weight infants, despite having fewer risk factors, say scientists at Lucile Packard Children's Hospital and Stanford's School of Medicine. The finding confirms prior research that showed a similar pattern in more recent immigrants, and suggests that physicians should consider their patients' ethnic backgrounds when planning their care.
"Now we see that the daughters of foreign-born women have similar issues," said Packard Children's neonatologist Ashima Madan, MD, "and that the indicators we have traditionally used to predict pregnancy outcomes - maternal educational level and age, and access to early prenatal care, for example - aren't reliable for every population." Madan is the lead author of the research, would be reported in the recent issue of the Journal of Pediatrics.
Scientists call the previously identified differences in pregnancy outcomes between Indian and Mexican immigrants the "dual paradox." That's because Mexican women giving birth in the United States are more likely than women from India to have healthy-sized newborns, even though they are less likely to have completed high school or to have initiated prenatal care during the first trimester of their pregnancy. In contrast, newborns of Indian immigrants, most of whom have completed college and begun prenatal care early, are more likely to deliver a low birth weight infant.........
Posted by: Emily Permalink Source
April 4, 2006, 9:25 PM CT
Lapatinib In The Treatment Of Breast Cancer
Based on the unanimous recommendation of an Independent Data Monitoring Committee (IDMC), GlaxoSmithKline announced that it has halted enrollment in its Phase III clinical trial evaluating the combination of Tykerb (lapatinib ditosylate) and capecitabine (Xeloda(R)) versus capecitabine alone.
The trial evaluated women with refractory advanced or metastatic breast cancer who have documented ErbB2 (HER2) overexpression and whose disease progressed following treatment with trastuzumab (Herceptin(R)) as well as other cancer therapies. A pre-planned interim analysis of 321 patients in the study yielded statistically significant results, exceeding the primary endpoint.
According to the study protocol, the pre-planned interim analysis was reviewed by the IDMC, which is comprised of medical oncology experts and a statistician. The IDMC unanimously recommended halting enrollment in the study because it exceeded its primary endpoint of time to disease progression, or TTP, for women receiving the combination of Tykerb and capecitabine. The IDMC made their recommendation based on pre-specified stopping rules outlined in their charter. All women currently enrolled in the trial will continue to be followed and those who are receiving capecitabine alone will be offered the option of switching to the combination therapy of capecitabine and Tykerb in consultation with their physician.........
Posted by: Janet Permalink Source
April 4, 2006, 8:50 PM CT
Preventing Injury To Muscles
If you're a mouse, then stretching before you exercise is a good thing - even as long as two weeks before your next cheese hunt or cat run. But if you're reading this for yourself, it's a bit more complicated.
When most of us think of stretching, we're imagining at a minimum jogging, and probably something more like downhill skiing or sprints. But when University of Michigan scientists Nicole Lockhart and Susan Brooks talk stretching, their real interest is how to condition older folks' muscles so they'll eventually be willing to do even a little exercise to garner all the benefits that will follow.
"The elderly are far more susceptible to contraction-induced injury," notes Lockhart, lead author in two related papers being presented in American Physiological Society sessions at Experimental Biology in San Francisco. "Sometimes just by normal activity or a sudden movement a leg will jut out too far and they'll suffer a minor injury, but they'll be wary of further damage," she said.Protect those muscles, as minor injuries may be cumulative
Brooks, her adviser, added: "We believe that cumulative muscle injury may contribute to the loss of muscle mass as we grow old. So protecting muscles at all times is a good thing. And understanding how stretching increases resistance to injury will really help to do this".........
Posted by: JoAnn Permalink Source
April 4, 2006, 8:39 PM CT
People With Allergies Are Less Likely To Develop Brain Tumors
In their quest to determine whether immune system surveillance guards against brain tumor development, scientists at The University of Texas M. D. Anderson Cancer Center have found that allergies and asthma that stimulate inflammation may be protective, but use of antihistamines to control the inflammation could eliminate that protection.
In this study, reported at the annual meeting of the American Association for Cancer Research (AACR), the scientists also associated chicken pox infection with a significantly reduced risk of developing brain tumors.
The scientists say the findings suggest that a small amount of inflammation in the brain may rev up the immune system enough to protect against brain tumor development. But they stress that no one should give up antihistamines or shun use of a chicken pox vaccine because of this study.
"Brain tumors are exceedingly rare, and a number of, a number of people use antihistamines, so we certainly are not suggesting a direct correlation between the two, or between chicken pox and tumors," says the study's lead author, Melissa Bondy, Ph.D., a professor in the Department of Epidemiology. "What this study may do is help us begin to understand if the immune system plays a role in development of different kinds of brain tumors".........
Posted by: JoAnn Permalink Source
April 4, 2006, 0:38 AM CT
Even At Rest, Men's And Women's Brains Behave Differently
A key part of the brain involved in processing emotionally influenced memories acts differently in men and women, even in the absence of stimuli, UC Irvine scientists have found.
Larry Cahill, an associate professor of neurobiology and behavior, and Lisa Kilpatrick, a former postdoctoral fellow in his laboratory, have found that the amygdala, an almond-shaped structure found on both sides of the brain, behaves very differently in males and females while the subjects are at rest. In men, the right amygdala is more active and shows more connections with other regions of the brain, even when there is no outside stimulus. On the other hand, in women, the left amygdala is more connected with other regions of the brain. In addition, the regions of the brain with which the amygdala communicates while a subject is at rest are different in men and women.
The finding could be key to determining why gender-related differences exist in certain psychiatric disorders and how to treat a variety of illnesses.
The study appears in this week's issue of NeuroImage.
"These findings are intriguing because they provide the first hint of what could be a fundamental difference in how the brain is wired in men and women," said Cahill, a fellow at UCI's Center for the Neurobiology of Learning and Memory. "If, even in a resting state, the brain shows such differences between the sexes, it could have far-reaching implications for our study of certain psychiatric and medical disorders".........
Posted by: Janet Permalink Source
April 4, 2006, 0:26 AM CT
Gene Rearrangement Involved In Prostate Cancer
Scientists at the University of Michigan Medical School have identified a third gene involved in prostate cancer, expanding their groundbreaking announcement, published last October in Science, that the majority of prostate cancers carry a malignancy-inducing fusion of genes never before seen in solid tumors.
The new findings are reported in the April 1 issue of Cancer Research. Since prostate cancer is a cancer of the epithelial cells lining organs, lead researcher Arul Chinnaiyan and colleagues believe it likely that other gene re-arrangements may be responsible for other cancers of epithelial tissue, including breast, colon and lung.
Scott Tomlins, a MD/PhD graduate student in Dr. Chinnaiyan's laboratory and the lead author of the Science paper, presented the study Tuesday, April 4, at Experimental Biology 2006 in San Francisco. The presentation was part of the scientific program of the American Society for Investigative Pathology (ASIP) held at Experimental Biology, and Mr. Tomlins is the winner of the 2006 ASIP Experimental Pathologist-in-Training Award.
The ETV4 gene is a member of the same family as the two other genes, ETV1 and ERG, reported earlier. All three are ETS genes, a group of approximately 30 genes that encode related transcription factors. Like other family members, ETV4 has a role in normal cell division but is uncommonly active, or overly expressive, only when it becomes fused with other genes on different chromosomes. Using the same technology as the earlier study, the researchers were able to demonstrate that the ETV4 gene had become fused with another prostate cancer gene on another chromosome.........
Posted by: Mark Permalink Source
April 4, 2006, 0:17 AM CT
Micro Pills To Deliver Drugs On Demand
Vesicle membranes that collapse when cooled may someday deliver minute payloads of medicines.
Credit: Sahraoui Chaieb, Univerity of Illinois at Urbana Champaign
Scientists have now crafted tiny, hollow capsules out of lipids--water-repellant molecules in the same family as fats and oils--that crumple and collapse when cooled below body temperature. The collapse squeezes out whatever chemicals are inside the miniscule ball in a controlled manner that could one day deliver drugs to the human body or improve cosmetics.
Developed by physicist and NSF (Faculty Early Career Development Program (CAREER) awardee Sahraoui Chaieb and colleagues at the University of Illinois at Urbana-Champaign, the capsules range in size from 10 to 100 micrometers (millionths of a meter) across.
For now, the capsules are in the earliest stages of development and still not ready for medical use, eventhough the scientists are discussing potential applications of the technology with a cosmetics company.
Before the capsules can be used to deliver medicine, the scientists say they must first develop a mechanism to cool the tiny pills without endangering surrounding body tissues.
The research was reported in the Feb. 17 issue of Physical Review Letters.........
Posted by: Scott Permalink Source
April 4, 2006, 0:09 AM CT
Supercomputer Maps One Million Atoms of a Complete Virus
For the first time, researchers have visualized the changing atomic structure of a virus by calculating how each of the virus' one million atoms interacted with each other every femtosecond--or one-millionth-of-a-billionth of a second. A better understanding of viral structures and mechanisms may one day allow researchers to design improved strategies to combat viral infections in plants, animals and even humans.
Led by Klaus Schulten at the University of Illinois at Urbana-Champaign, the team tapped the high-performance power of the National Center for Supercomputing Applications (NCSA) processors to accomplish the task. Still, it took about 100 days to generate just 50 nanoseconds of virus activity. Schulten says it would have taken the average desktop computer 35 years to come up with the results.
The simulation revealed key physical properties of satellite tobacco mosaic virus, a very simple, plant-infecting virus. Ultimately, scientists will generate longer simulations from bigger biological entities, but to do so, they need the next generation of supercomputers, the so-called "petascale high-performance computing systems." The National Science Foundation (NSF) is currently devising a national strategy for petascale computing to give scientists and engineers the resources needed to tackle their most computationally intensive research problems.........
Posted by: Scott Permalink Source
April 3, 2006, 11:56 PM CT
Lack Of Sleep May Lead To High Blood Pressure
If you're middle age and sleep five or less hours a night, you may be increasing your risk of developing high blood pressure, as per a research studyreleased by Columbia University's Mailman School of Public Health and the College of Physicians and Surgeons, and reported in Hypertension: Journal of the American Heart Association.
"Sleep allows the heart to slow down and blood pressure to drop for a significant part of the day," said James E. Gangwisch, PhD, lead author of the study and post-doctoral fellow in the psychiatric epidemiology training (PET) program at the Mailman School. "However, people who sleep for only short durations raise their average 24-hour blood pressure and heart rate. This may set up the cardiovascular system to operate at an elevated pressure".
Dr. Gangwisch said that 24 percent of people ages 32 to 59 who slept for five or fewer hours a night developed high blood pressure versus 12 percent of those who got seven or eight hours of sleep. Subjects who slept five or fewer hours per night continued to be significantly more likely to be diagnosed with high blood pressure after controlling for factors such as obesity, diabetes, physical activity, salt and alcohol consumption, smoking, depression, age, education, gender, and ethnicity.
The scientists conducted a longitudinal analysis of data from the Epidemiologic Follow-up Studies of the first National Health and Nutrition Examination Study (NHANES I). The analysis is based on NHANES I data from 4,810 people ages 32 to 86 who did not have hypertension at baseline. The 1982-84 follow-up survey asked participants how a number of hours they slept at night. During eight to 10 years of follow-up, 647 of the 4,810 participants were diagnosed with hypertension. Compared to people who slept seven or eight hours a night, people who slept five or fewer hours a night also exercised less and were more likely to have a higher body mass index. (BMI is a measurement used to assess body fatness). They were also more likely to have diabetes and depression, and to report daytime sleepiness.........
Posted by: Daniel Permalink Source