Category Archives: Health
Folks who walk to work or school while listening to music via headphones may want to unplug, with a new U.S. study finding injuries to this group of people tripling since 2004.
The reason, University of Maryland researchers say, is that use of iPods and other MP3 players makes people much less aware of their environment, including oncoming traffic.
“MP3 usage is common in young adults and teenagers and we found that people wearing headphones are at risk of getting hit and having injury or death,” said lead researcher Dr. Richard Lichenstein, an associate professor of pediatrics in Pediatric Emergency Medicine Research at the University of Maryland Children’s Hospital.
“These are pedestrians getting hit by cars, trains, trucks, vans, buses and things like that,” he said. “About 70 percent of the injuries were fatal and more than 50 percent of the victims were hit by trains.”
The report was published in the Jan. 16 online edition of Injury Prevention.
For the study, Lichenstein’s team used the U.S. National Electronic Injury Surveillance System, the U.S. Consumer Product Safety Commission and Google to find data on deaths and injuries among pedestrians wearing headphones from January 2004 through June 2011.
During this time, they found 116 such events reported. In 2004-05 just 16 such cases were noted, but that rate rose nearly three-fold to 47 during 2010-2011, the researchers report.
About two-thirds of victims were under 30 years of age, and the most common accident (55 percent) was being hit by a train. Most such accidents happened in cities, with only 12 percent occurring in rural areas.
In 70 percent of cases the accident proved fatal, and in three out of four, bystanders had actually seen the victim wearing headphones just prior to the accident. The sound coming from those headphones likely masked outside noise, because in 29 percent of the accidents, horns or sirens had been sounded just before the victim was hit.
“People wearing headphones need to be conscious of the outside environment and risk of moving vehicles, because not only are you distracted by the music, but also the sounds of traffic or horns or sirens are blocked,” Lichenstein said. Experts label this type of distraction “inattentional blindness.”
Commenting on the study, Dr. Carl Schulman, director of Injury Prevention Education at the University of Miami Miller School of Medicine, pointed to an earlier study suggesting that any form of impaired hearing can raise a person’s injury risk.
In a 1995 New Zealand study involving almost 200 children, those with (natural) hearing problems had an increased risk of being hit by a car, compared with children with normal hearing, Schulman noted.
This is similar to having one’s hearing intentionally blocked by music coming from headphones, so it is not surprising that the new study saw a similar pattern among people plugged into MP3 players, Schulman said.
Lichenstein said the way to reduce the risk is simple. “Be cognizant of the environment. Know there is risk out there. It’s not a great idea to be distracted and it’s not a great idea to shut out those sounds that may help you live another day,” he said.
Tall or short, it’s long been known that genes account for much of a person’s height. Now, scientists have found that short people actually might be missing copies of certain genes, which can leave them significantly smaller than average.
Studying DNA from more than 11,000 children and adults, an international team of researchers learned that those of short stature — defined roughly as falling into the shortest 2.5 percent of their peer group — had an excess number of rare deletions, or missing copies, of specific genes. Thus far, most research into genes and height has centered on identifying variations in common genes instead of an absence of others, study author Dr. Joel Hirschhorn said.
“We were a little bit surprised, since we didn’t really know what we would find going in [to the study] and whether we would see enough of an effect,” said Hirschhorn, a professor of genetics at Children’s Hospital Boston. “We were trying to figure out what’s the underlying genetics of height and things like it, and this is a class of variation less well studied.”
The study is published in the December issue of the American Journal of Human Genetics.
Common gene variants linked to height explain only about 10 percent of the variation in adult height, Hirschhorn said, but perhaps half of such variation might eventually be explained by some of the differences his team studied.
First analyzing the DNA of more than 4,400 children whose genetic material was collected for other purposes, the researchers observed that many more CNVs or “copy-number variants” — in this case, fewer copies of a gene — were present in those of short stature.
Extending the findings to a larger, population-based group of nearly 6,900 African Americans, the scientists again found that shorter participants had an excess of such missing gene copies. These deletions would typically be inherited from one’s parents, but not always, Hirschhorn said.
“Usually [researchers] look at variants one at a time, but this is a cumulative-effect type of variation,” said Hirschhorn, also a senior associate at the Broad Institute, a biomedical research organization in Cambridge, Mass.
Several limitations might affect the validity of the study results, the authors acknowledged. One is the fact that children whose DNA was evaluated had initially undergone genetic analysis for other reasons such as developmental delays, autism spectrum disorders and multiple birth defects. So it’s possible that those with many missing gene copies are likelier to have conditions leading to poor growth, the study said, but the replication of results in a more representative population suggests the findings can be generalized to others.
Estrogen therapy has already been credited with helping women manage an array of menopause-related issues, including reducing hot flashes, improving heart health and bone density, and maintaining levels of sexual satisfaction. Now a new study suggests that the same estrogen therapy used to treat osteoporosis can actually lead to healthier teeth and gums. The study outcomes are being published online today in Menopause, the journal of The North American Menopause Society (NAMS).
As estrogen levels fall during menopause, women become more vulnerable to numerous health issues, including loss of bone mineral density which can lead to osteoporosis. Around the same time, changes in oral health also are common as teeth and gums become more susceptible to disease, which can lead to inflammation, pain, bleeding, and eventually loose or missing teeth.
In the Menopause article “Association between osteoporosis treatment and severe periodontitis in postmenopausal women,” 492 postmenopausal Brazilian women aged 50 to 87 years, 113 in osteoporosis treatment and 379 not treated, were evaluated to determine whether osteoporosis treatment could help increase the bone mineral density in their jaws and, subsequently, improve overall oral health.
The study found that the rate of occurrence of severe periodontitis was 44% lower in the postmenopausal osteoporosis-treatment group than in the untreated group. Treatment consisted of systemic estrogen alone or estrogen plus progestin, as well as calcium and vitamin D supplements, for a minimum of six months.
“Osteoporosis can occur throughout the body, including the jaw, and lead to an increased risk of periodontal disease,” says Dr. JoAnn Pinkerton, NAMS executive director. “This study demonstrates that estrogen therapy, which has proven to be effective in preventing bone loss, may also prevent the worsening of tooth and gum disease. All women, but especially those with low estrogen or on bisphosphonate treatment for osteoporosis, should make good dental care a part of their healthy lifestyles.”
Now a team led by researchers at the Duke Cancer Institute have identified a cellular process that cancer cells hijack to hoard cholesterol and fuel their growth. Identifying this process could inform the development of better ways to control cholesterol accumulation in tumors, potentially leading to improved survival for prostate cancer patients.
The findings are published online this month in the journal Cancer Research.
“Prostate cancer cells, as well as some other solid tumors, have been shown to contain higher cholesterol levels than normal cells,” said senior author Donald McDonnell, Ph.D., chairman of the Department of Pharmacology and Cancer Biology at Duke. “All cells need cholesterol to grow, and too much of it can stimulate uncontrolled growth.
“Prostate cancer cells somehow bypass the cellular control switch that regulates the levels of cholesterol allowing them to accumulate this fat,” McDonnell said. “This process has not been well understood. In this study, we show how prostate cancer cells accomplish this.”
McDonnell and colleagues began by identifying genes involved in cholesterol regulation in prostate tumors. They homed in on a specific gene, CYP27A1, which is a key component of the machinery that governs the level of cholesterol within cells.
In patients with prostate cancer, the expression of the CYP27A1 gene in tumors is significantly lower, and this is especially true for men with aggressive cancers compared to the tumors in men with more benign disease. Downregulation of this gene basically shuts off the sensor that cells use to gauge when they have taken up enough cholesterol. This in turn allows accumulation of this fat in tumor cells. Access to more cholesterol gives prostate cancer cells a selective growth advantage.
“It remains to be determined how this regulatory activity can be restored and/or whether it’s possible to mitigate the effects of the increased cholesterol uptake that result from the loss of CYP27A1 expression,” McDonnell said.
He said statin use alone might help, but perhaps not enough, since tumors could simply rev up the regulation of the cholesterol manufacturing process in tumors to compensate.
McDonnell said is lab is continuing the research, including finding ways to induce cells to eject cholesterol, reverse the inhibition of CYP27A1 activity, or introduce compounds that interfere with cholesterol-production in the tumor.
“The effects of cognitive training in dementia patients have been studied actively during recent decades but the quality and reliability of the studies varies,” says licenced neuropsychologist Eeva-Liisa Kallio. She reviewed 31 randomized controlled trials on cognitive training in dementia patients.
Kallio’s reserch paper “Cognitive Training Interventions for Patients with Alzheimer’s Disease: A Systematic Review” was published inJournal of Alzheimer’s Disease.
Some of the studies in the review focused primarily on cognitive training and in others cognitive training was part of broader cognitive or multi-component intervention.
“Many of the studies reported effects on cognitive functions immediately after the intervention but only few studies included follow-up of the patients or showed improvement in cognitive functions that were not directly linked to the skills trained in the intervention,” Kallio says.
In the studies, cognitive functioning was measured before and after the intervention. Also questionnaires on psychological wellbeing, quality of life and activities of daily living were used.
According to Kallio’s review, the data from the previous studies is not adequate to give any recommendations on the use of cognitive training in the treatment of dementia patients. Even though the scientific evidence remains scarce, the studies do suggest that the training should be intensive or focus primarily on a particular aspect of cognitive functions.
“Healthy adults can get limited benefits from cognitive training but we need more high quality trials to confirm cognitive training as an effective treatment option in dementia,” Kallio says.
She belongs to the University of Helsinki’s FINCOG research group, led by professor Kaisu Pitkälä. The next step in the project is to study the effects of intensive, 3-month cognitive training on the community-dwelling older persons with dementia participating in adult day care activities organised by the City of Helsinki.
In this randomized controlled trial, part of the participants attend systematic cognitive training while their control group participates in the normal day care activities.
In addition to cognitive functions, also indicators of quality of life and activities of daily living are used and the measurements are repeated six months after the intervention. The research also includes a 24-month health register follow-up.
“Cognitive training is quite easy to implement. If our research suggests that the participants benefit from it, cognitive training can be easily included in the adult day care activities,” Kallio says.
“Our findings show that how we see directly relates to how others see us, through our facial expressions,” says psychological scientist Daniel H. Lee of the University of Colorado Boulder. “This is a clear demonstration of emotional embodiment, from sender to receiver.”
“For example, if you’re watching ‘Curb Your Enthusiasm’ and wonder why when Larry David squints his eyes that conveys scrutiny, our work offers a theory that explains it,” Lee explains. “Narrowing the eyes for visual scrutiny also communicates scrutiny.”
The idea that our facial expressions communicate emotion isn’t new — but Lee and co-author Adam K. Anderson of Cornell University wanted to understand how our expressions came to communicate so many complex emotions and mental states.
“We went back to Darwin,” says Lee. “His theories on how expression appearance evolved to have a sensory function for the sender showed how it also co-evolved to have communication function for the receiver.”
Opening our eyes wide boosts visual sensitivity by allowing more light in, helping us to see any threats that might lurk nearby. Narrowing our eyes to a squint, on the other hand, can increase visual acuity, helping us to discriminate fine details. Lee and Anderson hypothesized that these opposing types of expressions, which originated for optical purposes, may have been co-opted for social purposes, operating as signals of conceptually related mental states.
Using photos of faces included in widely-used databases, the researchers created average exemplars of six expressions (i.e., sadness, disgust, anger, joy, fear, surprise). On each trial, participants saw a pair of eyes (one of the six exemplars) and a word representing a specific mental state, and they rated the extent to which the mental-state term described the eye expression. Each participant completed a total of 600 trials. The researchers then analyzed how these mental state perceptions related to specific eye features: the openness of the eye; the distance from the eyebrow to the eye; the slope and curve of the eyebrow; and wrinkles around the nose, the temple, and below the eye.
Combined ratings from the 28 participants showed that the eyes really do provide a strong signal of emotional state. People consistently matched the eye expressions with the corresponding basic emotion, rating “fear” as a strong match for the fear eye expression, for example. And these ratings were reliably higher than those for other mental states paired with the same eye expression.
Additional analyses examining the relationship between specific eye features and mental states revealed four distinct clusters, two of which aligned with eye-narrowing and eye-widening features. The eye-narrowing cluster was associated with mental states related to social discrimination, including hate, suspicion, aggressiveness, and contempt. The eye-widening cluster was associated with mental states related to information sensitivity, including awe, anticipation, cowardice, and interest.
The fact that these two clusters associated so strongly around eye widening and narrowing surprised the researchers:
“Human expressions are highly complex — when enumerating our facial muscles, we computed that there are at least 3.7 x 1016different expression combinations, which is about the same probabilistic space as two Powerball jackpots,” says Lee. “We looked at a subset of this space — just the eye region — and found that one simple physical dimension (widening vs. narrowing) explained a majority of this complex space in social communication.”
Two additional clusters included eye features associated with joy, which aligned with positive mental states like admiration, and sadness, which aligned with negative mental states like uneasiness.
Findings from a second study showed that the eyes provide equally strong emotional signals when they’re embedded in the context of a whole face, even when the features in the lower face don’t indicate the same expression as the eyes do.
Thus, relative to the rest of our facial features, the eyes seem to have it when it comes to conveying complex mental states.
“This finding underscores how the origins of reading mental states from the eyes relate in part to how the eyes see,” the researchers write.
Duke Health scientists have identified a group of proteins that, when detected in specific quantities in the mucous, are 86 percent accurate in confirming the infection is from a cold or flu virus, according to a small, proof-of-concept trial published online in the journal EBioMedicine.
The researchers hope their initial work identifying the protein signature could aid the development of a quick, noninvasive doctor’s office test to determine the cause of upper respiratory illness and appropriate treatment.
“Every day, people are taking time off from work, going to emergency rooms, urgent care or their primary care doctors with symptoms of an upper respiratory infection,” said Geoffrey S. Ginsburg, M.D., Ph.D., a senior author of the paper and director of the Duke Center for Applied Genomics & Precision Medicine (DCAGPM), which led the study. “Looking for these proteins could be a relatively easy and inexpensive way of learning if a person has a viral infection, and if not, whether the use of antibiotics is appropriate.”
Although upper respiratory infections are among the most common reasons people visit the doctor in the U.S., health care providers lack tools to distinguish between a bacterial infection that might warrant antibiotics and a viral infection that would instead call for symptom relief.
Widespread use of antibiotics for upper respiratory infections don’t benefit patients with viral illness and can contribute to antibiotic-resistant superbugs, Ginsburg said. More precise diagnoses of these infections could be another tool to curb the development of superbugs, he said.
For the trial, researchers infected 88 healthy adult volunteers with a common strain of cold or flu virus.
Some participants didn’t get sick. Among those who developed infections, researchers found a distinct set of 25 proteins in fluid samples they gathered by flushing about 2 teaspoons of saline through the participant’s nasal passages.
Duke researchers in genomics and precision medicine have spent the past decade exploring strategies for differentiating bacterial and viral infections with the goal of developing cost-effective diagnostic tools doctors could use in their offices.
“In the past, science has focused on identifying the pathogen someone is infected with in the blood or other sample,” said lead author Thomas Burke, Ph.D., director of technology advancement and diagnostics at the DCAGPM. “Our approach flips the paradigm of how we look for infection. Instead of looking for the pathogen, we study the individual’s response to that pathogen and signature patterns in their genes, proteins, metabolites and other biomarkers.”
The Duke team has previously explored blood tests to examine a patient’s RNA for gene signatures to distinguish bacterial and viral infections in the upper respiratory tract and is working with a private company to develop potential diagnostics.
Analyzing proteins in mucous is a less invasive approach and requires less processing than blood samples. The researchers hope additional studies verify the initial results and lead to the development of a paper-based test that could be used in doctor’s offices or even at home to determine whether a doctor’s visit is necessary, said Christopher Woods, M.D., a senior author and associate director of applied genomics at the DCAGPM.
“The protein targets offer a faster, more cost-effective model for rapid screening and diagnoses of viral infections,” Woods said. “If the data are verified, the model could be valuable in many circumstances, such as rural settings or developing countries with less convenient access to health care, or even as an airport screening tool during an outbreak of a particularly threatening strain of flu.”
UT Southwestern Medical Center researchers report those findings in two recent studies, one in the Proceedings of the National Academy of Sciences (PNAS) and the second in Developmental Cell
“Many properties of aggressive cancer growth are driven by altered cell signaling,” said Dr. Sandra Schmid, senior author of both papers and Chair of Cell Biology at UT Southwestern. “We found that cancer cells are taking a page from the neuron’s signaling playbook to maintain certain beneficial signals and to squelch signals that would harm the cancer cells.”
The two studies find that dynamin1 (Dyn1) — a protein once thought to be present only in nerve cells of the brain and spinal cord — is also found in aggressive cancer cells. In nerve cells, or neurons, Dyn1 helps sustain neural transmission by causing rapid endocytosis — the uptake of signaling molecules and receptors into the cell — and their recycling back to the cell surface. These processes ensure that the neurons keep healthy supplies at the ready to refire in rapid succession and also help to amplify or suppress important nerve signals as necessary, Dr. Schmid explained.
“This role is what the cancer cells have figured out. Aggressive cancer cells have usurped the mechanisms that neurons use for the rapid uptake and recycling of neural transmitters. Instead of neural transmitters, the cancer cells use Dyn1 for rapid uptake and recycling of EGF (epidermal growth factor) receptors. Mutations in EGF receptors are drivers of breast and lung cancers,” she said of the Developmental Cell study.
In order to thrive, cancer cells must multiply faster than nearby noncancerous cells. EGF receptors help them do that, she explained.
Cancer cell survival is another factor in disease progression. In thePNAS study, the Schmid lab found that aggressive cancer cells appear to have adapted neuronal mechanisms to thwart a key cancer-killing pathway triggered by activating “death receptors” (DRs) on cancer cells. Specifically, aggressive cancer cells appear to have adapted ways to selectively activate Dyn1 to suppress DR signaling that usually leads to cancer cell death.
“It is amazing that the aggressive cancers use a signaling pathway to increase the activity of EGF and also turn on Dyn1 pathways to suppress cancer death — so you have this vicious circle,” said Dr. Schmid, who holds the Cecil H. Green Distinguished Chair in Cellular and Molecular Biology.
She stressed that less aggressive cancers respond to forms of chemotherapy that repress EGF signaling and/or die in response to the TRAIL-DR pathway. However, aggressive lung and breast cancer cells have adapted ways to commandeer the neuronal mechanisms identified in these studies.
The hope is that this research will someday lead to improved strategies to fight the most aggressive cancers, she said. Currently, her laboratory is conducting research to identify Dyn1 inhibitors as potential anticancer drugs using a 280,000-compound library in a shared facility at UT Southwestern.
“Cancer is a disease of cell biology. To grow, spread, and survive, cancer cells modify normal cellular behavior to their advantage. They can’t reinvent the underlying mechanisms, but can adapt them. In these studies, we find that some cancer cells repurpose tools that neurons use in order to get a competitive advantage over nearby normal cells,” she said.
The findings, reported in the journal Science Advances, are a first step toward developing more effective bone marrow treatments for diseases like leukemia and lymphoma.
Blood cells flow throughout the body delivering life-supporting oxygen and nutrients. As these cells are used and recycled they are regenerated by bone marrow, the soft tissue inside the body’s long and hollow bones.
Certain regions of bone marrow contain hematopoietic stem cells, the precursors of all blood and immune cells, said University of Illinois chemical and biomolecular engineering professor Brendan Harley, who led the research with postdoctoral researcher Ji Sun Choi.
“The tissue environment that surrounds these cells in the bone marrow provides a wealth of signals that can alter how these precursor cells behave. This paper looked at the signals provided by the tissue matrix itself,” said Harley, who also is affiliated with the Carl R. Woese Institute for Genomic Biology at the U. of I.
One of the major tools that oncologists use to treat leukemia and lymphoma involves transplanting HSCs. The donor stem cells must locate marrow cavities and start producing blood and immune cells. However, there is a limited quantity of available donor HSCs and the success rate of transplantation is low.
“We’re interested in this problem from an engineering standpoint,” Harley said. “The goal is to create better tools to both expand the number of donor HSCs and improve their capacity to repopulate the bone marrow after transplantation.”
Like cells throughout the body, HSCs are contained in a three-dimensional tissue environment known as the extracellular matrix. Harley and Choi gathered samples of HSCs from mice and then grew them in the laboratory using biomaterials engineered to mimic some of the extracellular matrix properties of the native bone marrow. Their goal was to examine how these engineered systems could alter the HSCs’ capacity to proliferate and differentiate to become blood cells.
The researchers examined two main elements of the matrix that regularly interact with HSCs: collagen and fibronectin. They found that the HSCs that were exposed to collagen proliferated more rapidly but that they had differentiated, meaning they were no longer stem cells. When exposed to fibronectin, the stem cells proliferated less rapidly, but were able to maintain their stem cell-like nature.
“With the collagen substrates, we got more cells but not useful cells,” Harley said. “With the right combination of stiffness in the matrix and the presence of fibronectin, we identified a class of biomaterials that show promise for being able to maintain and eventually expand these stem cells outside of the body. An engineered bone marrow will be of enormous value for treating hematopoietic cancers such as leukemia, but also for understanding the process of bone marrow failure and other hematopoietic diseases.”
This project is only the first step in controlling the signals from the matrix that influence HSCs, Harley said. He and other researchers in his lab are currently investigating other features of the matrix that can be manipulated to increase the number of stem cells and make them more effective in transplantation.
“We believe that ours is the first study to demonstrate a beneficial effect of lung-directed resveratrol treatments on aging lung function,” said Driscoll.
Resveratrol (RSL), a chemical found in red wine, is an antimicrobial chemical substance produced by plants to protect against infection and stress-related changes. It has previously been shown to support muscle metabolism when delivered orally.
RSL prophylaxis by inhalation was a novel measure taken by the research team as a potential approach for slowing age-related deterioration of lung function and structure by preserving alveolar epithelial type 2 cells (AEC2) which line alveoli (the tiny air sacs in the lungs through which the exchange of oxygen and carbon dioxide takes place) and produce surfactant which is vital for efficient breathing.
In healthy young adults, breathing is an essential, efficient process, but natural aging of the lung occurs at a steady and irreversible rate, as measured by a decline in lung function. This natural deterioration leads to a significantly reduced quality of life, over a time frame dependent on genetic and environmental factors. Although some available therapies can ameliorate symptoms, aging-related lung failure is generally irreversible and is accompanied by high rates of morbidity and mortality due to increased disease risk, including development of COPD, with accompanying emphysema and chronic bronchitis.
Using a rapidly aging mouse model, the research team investigated whether the accumulation of age-related degenerative changes in the lung could be slowed by inhaled RSL. Treatment cohorts received either RSL or vehicle by intratracheal (IT) instillation monthly for three months. One month following the final treatment, whole lung function and injury-related gene expression in AEC2 were assessed.
The research team found that inhaled, prophylactic resveratrol treatments can slow the rate of lung function decline, alveolar enlargement and alveolar epithelial type 2 cell DNA damage that occurs in the early stages of lung aging. They concluded that administration of resveratrol directly to the lungs may be an effective intervention for lung aging, which is a significant risk factor for development of chronic lung disease.
“While the natural deterioration of the human lung generally occurs over decades, the injury to lung cells is analogous to the lung cell damage that occurs in premature infants who experience respiratory distress before their lungs have fully developed,” added Driscoll. “Identifying a way to protect and strengthen young lungs before significant damage occurs is the goal of our research.”