Education doesn’t prevent cognitive decline
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Although a higher level of education attainment is associated with a higher level of cognitive functioning, it does not protect against cognitive decline in old age, contrary to the results of some reports, according to a study sponsored by the U.S. National Institutes of Health.
The association between higher educational attainment and reduced cognitive decline is based largely on studies that measured change at two points in time, study co-author, Dr. Robert S. Wilson, told Reuters Health.
“These studies have had difficulty separating education’s correlation with level of cognition from its correlation with rate of change. Studies such as ours that measure cognition at three or more time points are better able to separate these effects,” he said.
Hormone linked to depression after pregnancy
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Increased levels of corticotropin-releasing hormone (CRH), which is produced by the placenta, identifies women who are at risk for developing depression after their pregnancy ends, according to a study published in the Archives of General Psychiatry.
“The high incidence and severe consequences of postpartum depression make the identification of women at risk an important research goal,” Dr. Ilona S. Yim at the University of California, Irvine, and co-investigators write in their report. They point out that several lines of evidence link CRH, a key hormone involved in regulating many other hormones, to depressive symptoms following delivery.
To further investigate, the researchers conducted a study in which hormone levels in the blood were measured several times throughout pregnancy in 100 women, starting at week 15. Sixteen women developed postpartum depression.
Daytime impairments in older men with obstructive sleep apnea are related to total sleep time
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A study in the Feb. 1 issue of the journal SLEEP shows that daytime functional impairments in older men with obstructive sleep apnea (OSA) are largely explained by total sleep time rather than OSA severity.
A modest link between OSA severity and daytime sleepiness, measured by the Epworth Sleepiness Scale, was no longer statistically significant after controlling for total sleep time. Neither sleep disturbances, measured by the Pittsburgh Sleep Quality Index, nor sleep-related quality of life, measure by the Functional Outcome of Sleep Questionnaire, were associated with OSA severity; all three measures were modestly associated with total sleep time.
According to lead author Dr. Eric J. Kezirian, director of the division of sleep surgery in the department of otolaryngology at the University of California in San Francisco, the study shows that the functional consequences of OSA in older men may differ from those in younger populations and may need to be measured with instruments designed specifically for the demographic.
Pregnancy-related hormonal changes linked to increased risk of restless legs syndrome
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A study in the Feb. 1 issue of the journal Sleep shows that the elevation in estradiol levels that occurs during pregnancy is more pronounced in pregnant women with restless legs syndrome (RLS) than in controls.
During the last trimester of pregnancy, levels of the estrogenic steroid hormone estradiol were 34,211 pg/mL in women with RLS and 25,475 pg/mL in healthy controls. At three months postpartum, estradiol levels had dropped to 30.73 pg/mL in the RLS group and 94.92 pg/mL in controls. Other hormone levels did not differ significantly between the study groups.
According to the authors the data strongly suggest that estrogens play an important role in RLS during pregnancy. The study also supports previous reports of high RLS incidence in the last trimester of pregnancy when estradiol is maximally elevated.
Scattered light rapidly detects tumor response to chemotherapy
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New technology developed by Duke University bioengineers can help clinicians more precisely detect whether specific cancer drugs are working, and should give basic researchers a powerful new tool to better understand the underlying mechanisms of cancer development.
By interpreting how beams of light scatter off of tumor cell samples, researchers can determine if cancer cells are responding to chemotherapeutic agents within a matter of hours.
Most chemotherapy drugs work by forcing cancer cells to commit cellular suicide, a process known as apoptosis. As cells undergo this process, bodies within the cell, such as the nucleus or mitochondria, go through structural changes. Using the new approach, researchers can analyze the light scattered by these bodies to detect the apoptotic changes in real time.
“The new technology allowed us to detect the tell-tale signs of apoptosis in human breast cancer cells in as little as 90 minutes,” said Adam Wax, associate professor of biomedical engineering and senior member of the research team. “Currently, it can take between six and eight weeks to detect these changes clinically. It appears that this approach has the potential to be helpful in both clinical and laboratory settings.”
Ecologists report quantifiable measures of nature’s services to humans
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The idea of ecosystem services is a promising conservation concept but has been rarely put into practice. In a special issue of the journal Frontiers in Ecology and the Environment, researchers use novel tools to report some of the first quantifiable results that place values on nature’s services to humans.
“The idea of ‘ecosystem services’ – identifying and quantifying the resources and processes that nature provides for people – gives us a framework to measure nature’s contribution to human well-being,” write authors Peter Kareiva, guest editor for this issue and the chief scientist at The Nature Conservancy, and Susan Ruffo, director of ecosystem services programs at TNC, in an editorial in the issue. “It provides a credible way to link nature and people that goes beyond emotional arguments and points us toward practical solutions.”
Some of the best-described ecosystem services include pollination of crops, flood and storm protection, water filtration and recreation. The challenging part is translating these services into something with a measurable value. Economic valuation methods take changes in the supply of ecosystem services and translate these into changes in human welfare.
Rice eyes risks of quantum dots
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Quantum dots have the potential to bring many good things into the world: efficient solar power, targeted gene and drug delivery, solid-state lighting and advances in biomedical imaging among them.
But they may pose hazards as well.
A team of Rice researchers has been working to discover the health risks of quantum dots, molecule-sized semiconducting nanocrystals that are generally composed of heavy metals surrounded by an organic shell.
Pedro Alvarez, Rice’s George R. Brown Professor and chair of the Civil and Environmental Engineering Department, published a paper in ACS Environmental Science and Technology showing that under even mildly acidic or alkaline conditions, the shells can break down, releasing their toxic contents into the body or the environment. He coauthored the paper with colleagues Vicki Colvin, the Pitzer-Schlumberger Professor of Chemistry and in chemical and biological engineering, researcher Shaily Mahendra and postdoc Huiguang Zhu.
End-of-life care differs by race: study
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The way that older adults with advanced cancer live out their last days seems to vary based on race, a US study suggests.
Researchers found that of nearly 41,000 older Americans with terminal cancer, black and Asian patients were less likely than their white or Hispanic counterparts to be enrolled in a hospice program.
On the other hand, they were more likely to be hospitalized frequently or admitted to an intensive care unit near the end of their lives. They were also more likely than whites or Hispanics to die in the hospital, according to the study findings published in the Journal of the American Geriatrics Society.
School-supervised asthma therapy improves control
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New research suggests that adherence with daily asthma “controller” medications among children with asthma can be enhanced with school-based supervised asthma therapy.
As reported in the February issue of the journal Pediatrics, researchers assessed asthma control in 290 children from 36 schools who were randomized to receive school-based, supervised therapy or usual care.
For their study, Dr. Lynn B. Gerald and colleagues from the University of Alabama, Birmingham defined poor asthma control as at least one of the following: 1) absence from school due to asthma or respiratory illness, 2) average use of “rescue” asthma medication more than 2 times per week, or 3) at least 1 red or yellow reading on a peak flow meter, a device that measures air flow.
New CDC Study Assesses Impact of Genetic Testing on Health Outcomes
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Some genomic tests developed to personalize medical decisions about cancer care are beneficial, while for others the evidence is uncertain and reliance on the test might even lead to poorer medical management of cancer in some cases, according new recommendation statements from an expert panel. The statements appear in the January issue of Genetics in Medicine, the official peer-reviewed journal of The American College of Medical Genetics. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health, a leading provider of information and business intelligence for students, professionals, and institutions in medicine, nursing, allied health, pharmacy and the pharmaceutical industry.
Genetic tests for tumor gene expression in women with early-stage breast cancer to detect those at risk for cancer recurrence, the panel wrote, are based on insufficient evidence to determine whether they offer any improvement in health outcomes. The panel also found insufficient evidence to recommend testing for variants of the gene UGT1A1 in patients undergoing chemotherapy for metastatic colorectal cancer to inform use of the chemotherapy drug irinotecan. While the test might be useful in identifying patients at risk of side effects from the drug, reducing irinotecan dosage may be more harmful than the side effects, so the clinical utility of the UGT1A1 test is questionable, at best, it said.
On the other hand, genetic testing for Lynch syndrome, a hereditary condition that increases the risk of colorectal cancer, is useful to recommend screening relatives for the mutations that cause the syndrome and encouraging them to have regular colorectal cancer exams, the panel found.
Predicting the Future Spread of Infectious-Disease Vectors
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As global warming raises concerns about potential spread of infectious diseases, a team of researchers has demonstrated a way to predict the expanding range of human disease vectors in a changing world.
Researchers from Australia and the University of Wisconsin-Madison have identified the key biological and environmental factors constraining a population of the dengue fever vector, the mosquito Aedes aegypti. In a study publishing online Jan. 28 in the British Ecological Society’s journal Functional Ecology, they report that climate changes in Australia during the next 40 years and the insect’s ability to adapt to new conditions may allow the mosquitoes to expand into several populated regions of the continent, increasing the risk of disease transmission.
While the current study focuses on the Australian population of the dengue mosquito, these mosquitoes live around the world and present a global threat similar in scope to malaria, according to the Centers for Disease Control and Prevention. Study author and UW-Madison zoologist Warren Porter says that the Australian findings are likely to apply to other worldwide mosquito populations as well.
Mobile phone use not linked to eye cancer
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German investigators have reversed their previous finding that the use of mobile phones appears to be associated with an increased risk of developing melanoma of the eye (uveal melanoma); new results indicate that the association does not exist.
“We recently reported an increased risk of uveal melanoma for subjects who reported frequent use of mobile phones at work,” Dr. Andreas Stang, of Martin-Luther-University of Halle-Wittenberg, and colleagues note in the current Journal of the National Cancer Institute.
“However, this study suffered from incomplete exposure assessment and relatively low statistical power due to low exposure prevalence, which triggered some discussion about the validity of these findings,” they add.
Bilingual children more likely to stutter
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Young bilingual children have a heightened risk of stuttering, according to a new study. These children also have less chance of recovery from stuttering than monolingual speakers who stutter.
Bilingualism is considered a risk factor for stuttering, Dr. Peter Howell, of University College London, and colleagues point out in the Archives of Disease in Childhood, but “there is little information about how a second language affects the chances of stuttering onset and of recovery.”
Howell and colleagues studied a total of 317 children between the ages of 8 and 12 years who stuttered. The 69 children who were bilingual were matched to a group of fluent bilingual controls.
Scientists want DNA tests on Galileo for “eye test”
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Italian and British scientists want to exhume the body of 16th century astronomer Galileo for DNA tests to determine if his severe vision problems may have affected some of his findings.
The scientists told Reuters on Thursday that DNA tests would help answer some unresolved questions about the health of the man known as the father of astronomy, whom the Vatican condemned for teaching that the earth revolves around the sun.
“If we knew exactly what was wrong with his eyes we could use computer models to recreate what he saw in his telescope,” said Paolo Galluzzi, director of the Museum of History and Science in Florence, the city where Galileo is buried.
Sleep disordered breathing and obesity: Independent effects, causes
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In a study that addressed the issue of insulin sensitivity with respect to sleep disordered breathing (SDB), Naresh Punjabi, M.D., Ph.D. sought to examine the relationship between SDB and insulin resistance using the best tools at his disposal to do so.
The results definitively link SDB to pre-diabetic changes in insulin production and glucose metabolism. It was published in the first issue for February of the American Journal of Respiratory and Critical Care Medicine, published by the American Thoracic Society.
“In the past researchers have used body mass index, or BMI, as a proxy measure for body fat, but we know this to be a variable and crude tool to assess the true percentage of body fat,” said Dr. Punjabi. “In addition, previous studies have used surrogate measurements to assess the body’s response to insulin without investigating the interaction that occurs between reduced insulin sensitivity and increased insulin production in the body.”
