More dangerous chemicals in everyday life: Now experts warn against nanosilver
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Endocrine disrupters are not the only worrying chemicals that ordinary consumers are exposed to in everyday life. Also nanoparticles of silver, found in e.g. dietary supplements, cosmetics and food packaging, now worry scientists. A new study from the University of Southern Denmark shows that nano-silver can penetrate our cells and cause damage.
Silver has an antibacterial effect and therefore the food and cosmetic industry often coat their products with silver nanoparticles. Nano-silver can be found in e.g. drinking bottles, cosmetics, band aids, toothbrushes, running socks, refrigerators, washing machines and food packagings.
“Silver as a metal does not pose any danger, but when you break it down to nano-sizes, the particles become small enough to penetrate a cell wall. If nano-silver enters a human cell, it can cause changes in the cell”, explain Associate Professor Frank Kjeldsen and PhD Thiago Verano-Braga, Department of Biochemistry and Molecular Biology at the University of Southern Denmark.
Bisphenol A (BPA) at Very Low Levels Can Adversely Affect Developing Organs in Primates, MU Researcher Finds
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Bisphenol A (BPA) is a chemical that is used in a wide variety of consumer products, such as resins used to line metal food and beverage containers, thermal paper store receipts, and dental composites. BPA exhibits hormone-like properties, and exposure of fetuses, infants, children or adults to the chemical has been shown to cause numerous abnormalities, including cancer, as well as reproductive, immune and brain-behavior problems in rodents. Now, researchers at the University of Missouri have determined that daily exposure to very low concentrations of BPA by pregnant females also can cause fetal abnormalities in primates.
“BPA is an endocrine disrupting chemical that has been demonstrated to alter signaling mechanisms involving estrogen, androgen and thyroid hormones,” said Frederick vom Saal, Curators Professor of Biological Sciences in the College of Arts and Science at MU. “Previous studies in rodents have demonstrated that maternal exposure to very low doses of BPA can significantly alter fetal development, resulting in a variety of adverse outcomes in the fetus. Our study is one of the first to show this also happens in primates.”
Although BPA is considered a toxic chemical in other countries such as Canada, the U.S. has been slow to address the issue, said vom Saal. Until now, most studies involving BPA have been conducted on laboratory mice and rats, leading U.S. regulatory agencies to call for studies in primates. With funding provided by the National Institute of Environmental Health Sciences (NIEHS), a research institute of the National Institutes of Health, vom Saal and his colleagues studied the chemical’s blood levels in pregnant female rhesus monkeys and their fetuses, which are considered to be very similar to human fetuses.
Study Reveals Evolution at Work
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New research by UC Santa Barbara’s Kenneth S. Kosik, Harriman Professor of Neuroscience, reveals some very unique evolutionary innovations in the primate brain.
In a study published online today in the journal Neuron, Kosik and colleagues describe the role of microRNAs - so named because they contain only 22 nucleotides - in a portion of the brain called the outer subventricular zone (OSVZ). These microRNAs belong to a special category of noncoding genes, which prevent the formation of proteins.
“It’s microRNAs that provide the wiring diagram, dictating which genes are turned on, when they’re turned on and where they’re turned on,” said Kosik, who is also the co-director of UCSB’s Neuroscience Research Institute and a professor in the Department of Molecular, Cellular and Developmental Biology. “There’s a core set with which all kinds of really complex things can be built, and these noncoding genes know how to put it together.”
Vinegar kills tuberculosis and other mycobacteria
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The active ingredient in vinegar, acetic acid, can effectively kill mycobacteria, even highly drug-resistant Mycobacterium tuberculosis, an international team of researchers from Venezuela, France, and the US reports in mBio®, the online open-access journal of the American Society for Microbiology.
Acetic acid might be used as an inexpensive and non-toxic disinfectant against drug-resistant tuberculosis (TB) bacteria as well as other stubborn, disinfectant-resistant mycobacteria.
Work with drug-resistant tuberculosis bacteria carries serious biohazard risks. Chlorine bleach is often used to disinfect TB cultures and clinical samples, but bleach is toxic and corrosive. Other effective commercial disinfectants can be too expensive for TB labs in the resource-poor countries where the majority of TB occurs.
“Mycobacteria are known to cause tuberculosis and leprosy, but non-TB mycobacteria are common in the environment, even in tap water, and are resistant to commonly used disinfectants. When they contaminate the sites of surgery or cosmetic procedures, they cause serious infections. Innately resistant to most antibiotics, they require months of therapy and can leave deforming scars.” says Howard Takiff, senior author on the study and head of the Laboratory of Molecular Genetics at the Venezuelan Institute of Scientific Investigation (IVIC) in Caracas.
Study in fruitflies strengthens connection among protein misfolding, sleep loss, and age
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Pulling an “all-nighter” before a big test is practically a rite of passage in college. Usually, it’s no problem: You stay up all night, take the test, and then crash, rapidly catching up on lost sleep. But as we age, sleep patterns change, and our ability to recoup lost sleep diminishes.
Researchers at the Perelman School of Medicine, University of Pennsylvania, have been studying the molecular mechanisms underpinning sleep. Now they report that the pathways of aging and sleep intersect at the circuitry of a cellular stress response pathway, and that by tinkering with those connections, it may be possible to alter sleep patterns in the aged for the better - at least in fruit flies.
Nirinjini Naidoo, PhD, associate professor in the Center for Sleep and Circadian Neurobiology and the Division of Sleep Medicine, led the study with postdoctoral fellow Marishka Brown, PhD, which was published online before print in the journal Neurobiology of Aging.
Increasing age is well known to disrupt sleep patterns in all sorts of ways. Elderly people sleep at night less than their younger counterparts and also sleep less well. Older individuals also tend to nap more during the day. Naidoo’s lab previously reported that aging is associated with increasing levels of protein unfolding, a hallmark of cellular stress called the “unfolded protein response.”
Study reveals workings of working memory
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Keep this in mind: Scientists say they’ve learned how your brain plucks information out of working memory when you decide to act.
Say you’re a busy mom trying to wrap up a work call now that you’ve arrived home. While you converse on your Bluetooth headset, one kid begs for an unspecified snack, another asks where his homework project has gone, and just then an urgent e-mail from your boss buzzes the phone in your purse. During the call’s last few minutes these urgent requests - snack, homework, boss - wait in your working memory. When you hang up, you’ll pick one and act.
When you do that, according to Brown University psychology researchers whose findings appear in the journal Neuron, you’ll employ brain circuitry that links a specific chunk of the striatum called the caudate and a chunk of the prefrontal cortex centered on the dorsal anterior premotor cortex. Selecting from working memory, it turns out, uses similar circuits to those involved in planning motion.
In lab experiments with 22 adult volunteers, the researchers used magnetic resonance imaging to track brain activity during a carefully designed working memory task. They also measured how quickly the subjects could choose from working memory - a phenomenon the scientists called “output gating.”
An essential step toward printing living tissues
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A new bioprinting method developed at the Wyss Institute for Biologically Inspired Engineering at Harvard University and the Harvard School of Engineering and Applied Sciences (SEAS) creates intricately patterned 3D tissue constructs with multiple types of cells and tiny blood vessels. The work represents a major step toward a longstanding goal of tissue engineers: creating human tissue constructs realistic enough to test drug safety and effectiveness.
The method also represents an early but important step toward building fully functional replacements for injured or diseased tissue that can be designed from CAT scan data using computer-aided design (CAD), printed in 3D at the push of a button, and used by surgeons to repair or replace damaged tissue.
“This is the foundational step toward creating 3D living tissue,” said Jennifer Lewis, Ph.D., senior author of the study, who is a Core Faculty Member of the Wyss Institute for Biologically Inspired Engineering at Harvard University, and the Hansjörg Wyss Professor of Biologically Inspired Engineering at Harvard SEAS. Along with lead author David Kolesky, a graduate student in SEAS and the Wyss Institute, her team reported the results February 18 in the journal Advanced Materials.
Tissue engineers have tried for years to produce lab-grown vascularized human tissues robust enough to serve as replacements for damaged human tissue. Others have printed human tissue before, but they have been limited to thin slices of tissue about a third as thick as a dime. When scientists try to print thicker layers of tissue, cells on the interior starve for oxygen and nutrients, and have no good way of removing carbon dioxide and other waste. So they suffocate and die.
Family problems experienced in childhood and adolescence affect brain development
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The study led by Dr Nicholas Walsh, lecturer in developmental psychology at the University of East Anglia, used brain imaging technology to scan teenagers aged 17-19. It found that those who experienced mild to moderate family difficulties between birth and 11 years of age had developed a smaller cerebellum, an area of the brain associated with skill learning, stress regulation and sensory-motor control. The researchers also suggest that a smaller cerebellum may be a risk indicator of psychiatric disease later in life, as it is consistently found to be smaller in virtually all psychiatric illnesses.
Previous studies have focused on the effects of severe neglect, abuse and maltreatment in childhood on brain development. However the aim of this research was to determine the impact, in currently healthy teenagers, of exposure to more common but relatively chronic forms of ‘family-focused’ problems. These could include significant arguments or tension between parents, physical or emotional abuse, lack of affection or communication between family members, and events which had a practical impact on daily family life and might have resulted in health, housing or school problems.
Dr Walsh, from UEA’s School of Psychology, said: “These findings are important because exposure to adversities in childhood and adolescence is the biggest risk factor for later psychiatric disease. Also, psychiatric illnesses are a huge public health problem and the biggest cause of disability in the world.
FDA denies approval to wider use of J&J’s blood clot preventer
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The U.S. Food and Drug Administration denied an approval to a wider use of Johnson & Johnson’s heart drug Xarelto.
The blood-clot preventing drug is already approved for use in multiple indications.
J&J’s unit Janssen Research & Development was seeking approval for using the drug to reduce the risk of heart problems, such as heart attack, stroke or death, in patients with acute coronary syndrome and to reduce the risk of stent thrombosis - a blood clot at the site of the stent.
FDA Warns of Potential Risk of Severe Liver Injury With Use of Dronedarone
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The US Food and Drug Administration (FDA) is notifying healthcare professionals and patients about cases of rare, but severe liver injury, including 2 cases of acute liver failure leading to liver transplant, in patients treated with dronedarone (Multaq).
Information about the potential risk of liver injury from dronedarone is being added to the WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS sections of the dronedarone labels.
Dronedarone was approved with a Risk Evaluation and Mitigation Strategy (REMS) with a goal of preventing its use in patients with severe heart failure or who have recently been in the hospital for heart failure. In a study of patients with these conditions, patients given dronedarone had a greater than 2-fold increase in risk of death.
Healthcare professionals were reminded to advise patients to contact a healthcare professional immediately if they experience signs and symptoms of hepatic injury or toxicity (anorexia, nausea, vomiting, fever, malaise, fatigue, right upper quadrant pain, jaundice, dark urine, or itching) while taking dronedarone.
ADHD drugs not linked to increased stroke risk among children
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Children who take medication to treat attention deficit hyperactivity disorder (ADHD) don’t appear to be at increased stroke risk, according to a study presented at the American Stroke Association’s International Stroke Conference 2014.
In a study of 2.5 million 2- to 19-year-olds over a 14-year period, researchers compared stimulant medication usage in children diagnosed with ischemic or hemorrhagic stroke to stimulant usage in children without stroke. Researchers found no association between stroke risk and the use of ADHD stimulant medications at the time of stroke or at any time prior to stroke.
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Note: Actual presentation is 5:20 p.m. PT Wednesday, Feb. 12, 2014.
Follow news from the American Stroke Association’s International Stroke Conference 2014 via Twitter: @HeartNews #ISC14.
Laboratory detective work points to potential therapy for rare, drug-resistant cancer
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University of Pittsburgh Cancer Institute (UPCI) scientists have shown that old drugs might be able to do new tricks.
By screening a library of FDA-approved anticancer drugs that previously wouldn’t have been considered as a treatment for a rare type of cancer, UPCI scientists were surprised when they found several potential possibilities to try if the cancer becomes resistant to standard drug treatment.
The discovery, which will be published in the February 15th issue of Cancer Research, demonstrates that high-throughput screening of already FDA-approved drugs can identify new therapies that could be rapidly moved to the clinic.
“This is known as ‘drug repurposing,’ and it is an increasingly promising way to speed up the development of treatments for cancers that do not respond well to standard therapies,” said senior author Anette Duensing, M.D., assistant professor of pathology at UPCI. “Drug repurposing builds upon previous research and development efforts, and detailed information about the drug formulation and safety is usually available, meaning that it can be ready for clinical trials much faster than a brand-new drug.”
Targeting tumors: Ion beam accelerators take aim at cancer
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EVENT: Advances in the design and operation of particle accelerators built for basic physics research are leading to the rapid evolution of machines that deliver cancer-killing beams. Hear about the latest developments and challenges in this field from a physicist, a radiobiologist, and a clinical oncologist, and participate in a discussion about cost, access, and ethics at a symposium organized by the U.S. Department of Energy’s Brookhaven National Laboratory (“Targeting Tumors: Ion Beam Accelerators Take Aim at Cancer”) and at a related press briefing—both to be held at the 2014 meeting of the American Association for the Advancement of Science.
WHEN: Sunday, February 16, 2014, 8:00 a.m. Central Time (symposium) and 11:00 a.m. (press briefing)
WHERE: Symposium: Hyatt Regency Chicago, Grand Ballroom A; Press Briefing: Swissotel, AAAS briefing room, adjacent to the newsroom, second floor.
WEBCAST: For reporters unable to attend the meeting, the press briefing portion will be webcast live and archived in the AAAS meeting newsroom.
Link confirmed between salmon migration, magnetic field
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A team of scientists last year presented evidence of a correlation between the migration patterns of ocean salmon and the Earth’s magnetic field, suggesting it may help explain how the fish can navigate across thousands of miles of water to find their river of origin.
This week, scientists confirmed the connection between salmon and the magnetic field following a series of experiments at the Oregon Hatchery Research Center in the Alsea River basin. Researchers exposed hundreds of juvenile Chinook salmon to different magnetic fields that exist at the latitudinal extremes of their oceanic range. Fish responded to these “simulated magnetic displacements” by swimming in the direction that would bring that toward the center of their marine feeding grounds.
The study, which was funded by Oregon Sea Grant and the Oregon Department of Fish and Wildlife, will be published this month in the forthcoming issue of Current Biology.
“What is particularly exciting about these experiments is that the fish we tested had never left the hatchery and thus we know that their responses were not learned or based on experience, but rather they were inherited,” said Nathan Putman, a postdoctoral researcher at Oregon State University and lead author on the study.
Immune system ‘overdrive’ in pregnant women puts male child at risk for brain disorders
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Johns Hopkins researchers report that fetal mice - especially males - show signs of brain damage that lasts into their adulthood when they are exposed in the womb to a maternal immune system kicked into high gear by a serious infection or other malady. The findings suggest that some neurologic diseases in humans could be similarly rooted in prenatal exposure to inflammatory immune responses.
In a report on the research published online last week in the journal Brain, Behavior and Immunity, the investigators say that the part of the brain responsible for memory and spatial navigation (the hippocampus) was smaller over the long term in the male offspring exposed to the overactive immune system in the womb. The males also had fewer nerve cells in their brains and their brains contained a type of immune cell that shouldn’t be present there.
“Our research suggests that in mice, males may be more vulnerable to the effects of maternal inflammation than females, and the impact may be life long,” says study leader Irina Burd, M.D., Ph.D., an assistant professor of gynecology/obstetrics and neurology at the Johns Hopkins University School of Medicine and director of the Integrated Research Center for Fetal Medicine. “Now we wonder if this could explain why more males have diseases such as autism and schizophrenia, which appear to have neurobiological causes.”
For the study, researchers sought to mimic the effects of a maternal infection or other condition that causes inflammation in a pregnant mother. This type of inflammation between 18 and 32 weeks of gestation in humans has been linked to preterm birth as well as an imbalance of immune cells in the brain of the offspring and even death of nerve cells in the brains of those children. Burd and her colleagues used a mouse model to study what happens to the brains of those offspring as they age into adulthood to see if the effects persisted.
