New Capsicum annuum pepper contains high concentrations of beneficial capsinoids

Researchers have released a new Capsicum annuum pepper germplasm that contains high concentrations of capsinoids. The release was announced in the January 2014 issue of HortScience by researchers Robert L. Jarret from the USDA/Agricultural Research Service in Griffin, Georgia, in collaboration with Jason Bolton and L. Brian Perkins from the Department of Food Science and Human Nutrition at the University of Maine.According to the report, the germplasm called “509-45-1” is a small-fruited Capsicum annuum L. pepper. Fruit of 509-45-1 contain high concentrations of capsiate in both immature and mature fruit. “The release of 509-45-1 will provide researchers and plant breeders with a new source of capsinoids, thus facilitating the production of and further research on these non-pungent biologically active compounds,” Jarret said.Pungent capsaicinoids–the compounds found in the capsicum family of plants that give them their signature heat–have many benefits. Unfortunately, their use as ingredients in foods and pharmaceuticals has been limited by the very characteristic that makes them popular as a spice–their pungency. Non-pungent capsinoids, analogs of capsaicinoids, were first isolated from a sweet pepper cultivar. Capsinoids offer similar types of biological activity as capsaicinoids without the pungency, and are known to provide antioxidant activity, enhance adrenal function, promote metabolism, and suppress body fat accumulation.The scientists began the breeding process in 2005 by screening 120 Capsicum annuum cultivars for the occurrence of capsinoids. …

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Ban Asbestos in Unity – a very powerful message in the sands of Greens Beach Tasmania

A few days ago while I was walking along the beautiful and peaceful beach at a little cove/seaside town in Tasmania called Greens Beach, as there was no one else on the beach I decided spur of the moment to draw this heart in the sand with this powerful message as I felt it reaches out worldwide with a very important message.I stood back and went to take a photograph when all of a sudden a couple appeared from ‘no where’ and asked if they could ‘take a look at my artwork’! I showed them, they looked at each other and went a pale shade of grey and said ”a friend of ours was recently diagnosed with pleural mesothelioma and he lives in Launceston’! (Launceston …

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Harnessing everyday motion to power mobile devices

Imagine powering your cell phone by simply walking around your office or rubbing it with the palm of your hand. Rather than plugging it into the wall, you become the power source. Researchers at the 247th National Meeting & Exposition of the American Chemical Society (ACS) presented these commercial possibilities and a unique vision for green energy.The meeting, attended by thousands of scientists, features more than 10,000 reports on new advances in science and other topics. It is being held at the Dallas Convention Center and area hotels through Thursday.Zhong Lin Wang, Ph.D., and his team, including graduate student Long Lin who presented the work, have set out to transform the way we look at mechanical energy. Conventional energy sources have so far relied on century-old science that requires scattered, costly power plants and a grid to distribute electricity far and wide.”Today, coal, natural gas and nuclear power plants all use turbine-engine driven, electromagnetic-induction generators,” Wang explained. “For a hundred years, this has been the only way to convert mechanical energy into electricity.”But a couple of years ago, Wang’s team at the Georgia Institute of Technology was working on a miniature generator based on an energy phenomenon called the piezoelectric effect, which is electricity resulting from pressure. But to their surprise, it produced more power than expected. They investigated what caused the spike and discovered that two polymer surfaces in the device had rubbed together, producing what’s called a triboelectric effect — essentially what most of us know as static electricity.Building on that fortuitous discovery, Wang then developed the first triboelectric nanogenerator, or “TENG.” He paired two sheets of different materials together — one donates electrons, and the other accepts them. When the sheets touch, electrons flow from one to the other. When the sheets are separated, a voltage develops between them.Since his lab’s first publication on TENG in 2012, they have since boosted the power output density by a factor of 100,000, with the output power density reaching 300 Watts per square meter. …

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Single chip device to provide real-time 3-D images from inside the heart, blood vessels

Researchers have developed the technology for a catheter-based device that would provide forward-looking, real-time, three-dimensional imaging from inside the heart, coronary arteries and peripheral blood vessels. With its volumetric imaging, the new device could better guide surgeons working in the heart, and potentially allow more of patients’ clogged arteries to be cleared without major surgery.The device integrates ultrasound transducers with processing electronics on a single 1.4 millimeter silicon chip. On-chip processing of signals allows data from more than a hundred elements on the device to be transmitted using just 13 tiny cables, permitting it to easily travel through circuitous blood vessels. The forward-looking images produced by the device would provide significantly more information than existing cross-sectional ultrasound.Researchers have developed and tested a prototype able to provide image data at 60 frames per second, and plan next to conduct animal studies that could lead to commercialization of the device.”Our device will allow doctors to see the whole volume that is in front of them within a blood vessel,” said F. Levent Degertekin, a professor in the George W. Woodruff School of Mechanical Engineering at the Georgia Institute of Technology. “This will give cardiologists the equivalent of a flashlight so they can see blockages ahead of them in occluded arteries. It has the potential for reducing the amount of surgery that must be done to clear these vessels.”Details of the research were published online in the February 2014 issue of the journal IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control. Research leading to the device development was supported by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), part of the National Institutes of Health.”If you’re a doctor, you want to see what is going on inside the arteries and inside the heart, but most of the devices being used for this today provide only cross-sectional images,” Degertekin explained. “If you have an artery that is totally blocked, for example, you need a system that tells you what’s in front of you. …

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Researchers hijack cancer migration mechanism to ‘move’ brain tumors

One factor that makes glioblastoma cancers so difficult to treat is that malignant cells from the tumors spread throughout the brain by following nerve fibers and blood vessels to invade new locations. Now, researchers have learned to hijack this migratory mechanism, turning it against the cancer by using a film of nanofibers thinner than human hair to lure tumor cells away.Instead of invading new areas, the migrating cells latch onto the specially-designed nanofibers and follow them to a location — potentially outside the brain — where they can be captured and killed. Using this technique, researchers can partially move tumors from inoperable locations to more accessible ones. Though it won’t eliminate the cancer, the new technique reduced the size of brain tumors in animal models, suggesting that this form of brain cancer might one day be treated more like a chronic disease.”We have designed a polymer thin film nanofiber that mimics the structure of nerves and blood vessels that brain tumor cells normally use to invade other parts of the brain,” explained Ravi Bellamkonda, lead investigator and chair of the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “The cancer cells normally latch onto these natural structures and ride them like a monorail to other parts of the brain. By providing an attractive alternative fiber, we can efficiently move the tumors along a different path to a destination that we choose.”Details of the technique were reported February 16 in the journal Nature Materials. The research was supported by the National Cancer Institute (NCI), part of the National Institutes of Health; by Atlanta-based Ian’s Friends Foundation, and by the Georgia Research Alliance. In addition to the Coulter Department of Biomedical Engineering, the research team included Children’s Healthcare of Atlanta and Emory University.Treating the Glioblastoma multiforme cancer, also known as GBM, is difficult because the aggressive and invasive cancer often develops in parts of the brain where surgeons are reluctant to operate. Even if the primary tumor can be removed, however, it has often spread to other locations before being diagnosed.New drugs are being developed to attack GBM, but the Atlanta-based researchers decided to take a more engineering approach. …

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For celebrated frog hops, scientists look to Calaveras pros

Oct. 16, 2013 — The Calaveras County Jumping Frog Jubilee has entered the scientific record via a new paper in the Journal of Experimental Biology. Experienced bullfrog ‘jockeys’ at the event routinely get their frogs to jump much farther than researchers had ever measured in the lab. How? Decades of refined technique, uncommonly motivated humans and herps, and good old-fashioned large sample size.One day, amid his decades-long study of how animals move, including how frogs jump, Brown University biologist Thomas Roberts found himself and colleague Richard Marsh puzzling over the Guinness Book of World Records. A bullfrog named Rosie the Ribeter reportedly had jumped more than 2.1 meters in a single hop at the Calaveras County Jumping Frog Jubilee in 1986, but scientific studies had never reported a bullfrog jump beyond 1.3 meters.”It was sort of shocking; we worried about it,” Roberts said. “Maybe we were missing something but we also had a little bit of uncertainty and skepticism.”Why worry? There are many important reasons why scientists want to know the truly maximal performance of an animal. It informs studies of how physiology and biomechanics work, such as the interplay of tendon and muscle. It also allows biologists to formulate new hypotheses about species evolution, and provides benchmarks of animal health.What if scientists weren’t eliciting true maximal performance? …

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Packaging stem cells in capsules for heart therapy

Oct. 11, 2013 — Stem cell therapy for heart disease is happening. Around the world, thousands of heart disease patients have been treated in clinical studies with some form of bone marrow cells or stem cells. But in many of those studies, the actual impact on heart function was modest or inconsistent. One reason is that most of the cells either don’t stay in the heart or die soon after being introduced into the body.Cardiology researchers at Emory have a solution for this problem. The researchers package stem cells in a capsule made of alginate, a gel-like substance. Once packaged, the cells stay put, releasing their healing factors over time.Researchers used encapsulated mesenchymal stem cells to form a “patch” that was applied to the hearts of rats after a heart attack. Compared with animals treated with naked cells (or with nothing), rats treated with the capsule patches displayed increased heart function, reduced scar size and more growth of new blood vessels a month later. In addition, many more of the encapsulated cells stayed alive.”This approach appears to be an effective way to increase cell retention and survival in the context of cardiac cell therapy,” says W. Robert Taylor, MD, professor of medicine and director of the cardiology division at Emory University School of Medicine and professor in the Wallace H. …

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Unusual mechanism of DNA synthesis could explain genetic mutations

Sep. 11, 2013 — Researchers have discovered the details of how cells repair breaks in both strands of DNA, a potentially devastating kind of DNA damage.When chromosomes experience double-strand breaks due to oxidation, ionizing radiation, replication errors and certain metabolic products, cells utilize their genetically similar chromosomes to patch the gaps via a mechanism that involves both ends of the broken molecules. To repair a broken chromosome that lost one end, a unique configuration of the DNA replication machinery is deployed as a desperation strategy to allow cells to survive, the researchers discovered.The collaborative work of graduate students working under Anna Malkova, associate professor of biology at Indiana University-Purdue University Indianapolis (IUPUI) and Kirill Lobachev, associate professor of biology at the Georgia Institute of Technology, was critical in the advancement of the project. The group’s research was scheduled to be published Sept. 11 in the online edition of the journal Nature, with two graduate students, Sreejith Ramakrishnan of IUPUI, and Natalie Saini of Georgia Tech, as first authors. Other collaborators include James Haber of Brandeis University and Grzegorz Ira of the Baylor College of Medicine.”Previously we have shown that the rate of mutations introduced by break-induced replication is 1,000 times higher as compared to the normal way that DNA is made naturally, but we never understood why,” Malkova said.Lobachev’s lab used cutting-edge analysis techniques and equipment available at only a handful of labs around the world. This allowed the researchers to see inside yeast cells and freeze the break-induced DNA repair process at different times. They found that this mode of DNA repair doesn’t rely on the traditional replication fork — a Y-shaped region of a replicating DNA molecule — but instead uses a bubble-like structure to synthesize long stretches of missing DNA. This bubble structure copies DNA in a manner not seen before in eukaryotic cells.Traditional DNA synthesis, performed during the S-phase of the cell cycle, is done in semi-conservative manner as shown by Matthew Meselson and Franklin Stahl in 1958 shortly after the discovery of the DNA structure. They found that two new double helices of DNA are produced from a single DNA double helix, with each new double helix containing one original strand of DNA and one new strand.”We demonstrated that break-induced replication differs from S-phase DNA replication as it is carried out by a migrating bubble instead of a normal replication fork and leads to conservative DNA synthesis promoting highly increased mutagenesis,” Malkova said.This desperation replication triggers “bursts of genetic instability” and could be a contributing factor in tumor formation.”From the point of view of the cell, the whole idea is to survive, and this is a way for them to survive a potentially lethal event, but it comes at a cost,” Lobachev said. …

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Molecular beacons light path to cardiac muscle repair

Sep. 5, 2013 — Pure cardiac muscle cells, ready to transplant into a patient affected by heart disease.That’s a goal for many cardiology researchers working with stem cells. Having a pure population of cardiac muscle cells is essential for avoiding tumor formation after transplantation, but has been technically challenging.Researchers at Emory and Georgia Tech have developed a method for purifying cardiac muscle cells from stem cell cultures using molecular beacons.Molecular beacons are tiny “instruments” that become fluorescent only when they find cells that have turned on certain genes. In this case, they target instructions to make a type of myosin, a protein found in cardiac muscle cells.Doctors could use purified cardiac muscle cells to heal damaged areas of the heart in patients affected by heart attack and heart failure. In addition, the molecular beacons technique could have broad applications across regenerative medicine, because it could be used with other types of cells produced from stem cell cultures, such as brain cells or insulin-producing islet cells.The results are published in the journal Circulation.”Often, we want to generate a particular cell population from stem cells for introduction into patients,” says co-senior author Young-sup Yoon, MD, PhD, professor of medicine (cardiology) and director of stem cell biology at Emory University School of Medicine. “But the desired cells often lack a readily accessible surface marker, or that marker is not specific enough, as is the case for cardiac muscle cells. This technique could allow us to purify almost any type of cell.”Gang Bao, PhD, whose laboratory has pioneered the design and use of molecular beacons, is co-senior author. Bao is Robert A. Milton chair, Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. …

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Pain-free microneedle influenza vaccine is effective, long-lasting

Sep. 4, 2013 — Scientists have developed an influenza vaccine delivered via microneedle patch that provided 100 percent protection against a lethal influenza virus in mice more than one year after vaccination. They report their findings in the September 2013 issue of the journal Clinical and Vaccine Immunology.Share This:Microneedles are a medium for delivery of influenza vaccine that avoids the pain associated with ordinary hypodermic needles. They are a mere seven tenths of a millimeter in length, and the volume of vaccine — a major contributor to pain — is minuscule.Instead of a liquid containing whole killed or attenuated virus, this vaccine uses dry virus-like particles (VLPs) which simply coat the needles in the presence of a simple stabilizing agent, reducing the need for refrigeration — a potential boon for use in developing countries. The lower dose required when using microneedles also reduces the potential for side effects, such as lung inflammation.”This method can induce higher levels of IgG2a antibodies as well as rapid recall immune responses following lethal challenge infection. Our previous study showed that microneedle vaccination induced higher levels of antibody-secreting cells in spleen and bone marrow compared to intramuscular vaccination,” says Sang-Moo Kang of Georgia State University, a researcher on the study.Earlier studies by this group showed that influenza VLP-coated microneedles actually produced higher short-term protection than conventional intramuscular immunization. In this study the researchers tested how effective the long-term protection of the vaccine was. Mice that received the vaccine were 100 percent protected from a lethal challenge with the influenza virus 14 months after vaccination.Kang says his aim was to develop an easier and pain-free method of vaccine delivery. He also says that patients could probably use this system to vaccinate themselves.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length. …

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Food source for whales, seals and penguins at risk: Warming Antarctic seas likely to impact on krill habitats

Aug. 22, 2013 — Antarctic krill are usually less than 6 cm in length but their size belies the major role they play in sustaining much of the life in the Southern Ocean. They are the primary food source for many species of whales, seals, penguins and fish.Krill are known to be sensitive to sea temperature, especially in the areas where they grow as adults. This has prompted scientists to try to understand how they might respond to the effects of further climate change.Using statistical models, a team of researchers from the British Antarctic Survey and Plymouth Marine Laboratory assessed the likely impact of projected temperature increases on the Weddell Sea, Scotia Sea and Southern Drake Passage, which is known for its abundance of krill. This region has experienced sea surface warming of as much as 1°C over fifty years. Projections suggest this could rise by another 1°C by the end of the 21st century.The models are based on equations which link krill growth, sea surface temperature, and food availability. An analysis of the results, published this week in the online journal PLOS ONE, suggests warming, if continued, could reduce the area of growth habitat by up to 20%.In the early life stages krill require deep water with low acidity and a narrow range of temperatures for their eggs to successfully hatch and develop. The larvae then feed on algae on the underside of sea ice.The adults require suitable temperatures and enough of the right type of food (larger phytoplankton) to successfully grow and reproduce. Many of these critical environmental features (temperature, acidity, sea ice and food availability) could be affected by climate change.The projected effects of warming are not evenly spread. The island of South Georgia is located within the area likely to be worst affected. …

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Researchers use nanoparticles to fight cancer

Aug. 14, 2013 — Researchers at the University of Georgia are developing a new treatment technique that uses nanoparticles to reprogram immune cells so they are able to recognize and attack cancer.The findings were published recently in the early online edition of ACS Nano.The human body operates under a constant state of martial law. Chief among the enforcers charged with maintaining order is the immune system, a complex network that seeks out and destroys the hordes of invading bacteria and viruses that threaten the organic society as it goes about its work.The immune system is good at its job, but it’s not perfect. Most cancerous cells, for example, are able to avoid detection by the immune system because they so closely resemble normal cells, leaving the cancerous cells free to multiply and grow into life-threatening tumors while the body’s only protectors remain unaware.Shanta Dhar and her colleagues are giving the immune system a boost through their research.”What we are working on is specifically geared toward breast cancer,” said Dhar, the study’s co-author and an assistant professor of chemistry in the UGA Franklin College of Arts and Sciences. “Our paper reports for the first time that we can stimulate the immune system against breast cancer cells using mitochondria-targeted nanoparticles and light using a novel pathway.”In their experiments, Dhar and her colleagues exposed cancer cells in a petri dish to specially designed nanoparticles 1,000 times finer than the width of a human hair. The nanoparticles invade the cell and penetrate the mitochondria — the organelles responsible for producing the energy a cell needs to grow and replicate.They then activated the nanoparticles inside the cancer cells by exposing them to a tissue-penetrating long wavelength laser light. Once activated, the nanoparticles disrupt the cancer cell’s normal processes, eventually leading to its death.The dead cancer cells were collected and exposed to dendritic cells, one of the core components of the human immune system. What the researchers saw was remarkable.”We are able to potentially overcome some of the traditional drawbacks to today’s dendritic cell immunotherapy,” said Sean Marrache, a graduate student in Dhar’s lab. “By targeting nanoparticles to the mitochondria of cancer cells and exposing dendritic cells to these activated cancer cells, we found that the dendritic cells produced a high concentration of chemical signals that they normally don’t produce, and these signals have traditionally been integral to producing effective immune stimulation.”Dhar added that the “dendritic cells recognized the cancer as something foreign and began to produce high levels of interferon-gamma, which alerts the rest of the immune system to a foreign presence and signals it to attack. We basically used the cancer against itself.”She cautions that the results are preliminary, and the approach works only with certain forms of breast cancer. …

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Higher cancer incidences found in regions near refineries and plants that release benzene

July 29, 2013 — The incidence of a particular type of blood cancer is significantly higher in regions near facilities that release the chemical benzene into the environment. That is the conclusion of a new study published early online in Cancer, a peer-reviewed journal of the American Cancer Society. This and other studies like it will be critical to identifying and enacting public health policies to decrease or prevent cancer.Share This:Non-Hodgkin lymphoma has been on the rise over the past few decades as industrial production in the United States has expanded. Benzene is one chemical carcinogen linked to blood cancers. Working with Dr. Christopher Flowers and colleagues in the Lymphoma Program at Emory University in Atlanta, Catherine Bulka, MPH, used publicly available data from the Environmental Protection Agency and the US Census Bureau to analyse the geographic patterns of non-Hodgkin lymphoma cases in the state of Georgia between 1999 and 2008. This group examined the associations between new cases of lymphoma and the locations of facilities — such as petroleum refineries and manufacturing plants — that released benzene into the surrounding air or water.The investigators found that the metro-Atlanta region, Augusta, and Savannah had the highest incidence of non-Hodgkin lymphoma even when controlling for population size as well as for age, sex, and race demographics of the local region. Also, the incidence of non-Hodgkin lymphoma was significantly greater than expected surrounding benzene release sites located in the metro-Atlanta area and surrounding one benzene release site in Savannah. For every mile the average distance to benzene release sites increased, there was a 0.31 percent decrease in the risk of non-Hodgkin lymphoma.”Our study is the first to examine the relationship between passive benzene exposure and the incidence of non-Hodgkin lymphoma at the state population level,” said Bulka. “Our findings are limited without similar studies to corroborate our results, but we hope that our research will inform readers of the potential risks of living near facilities that release carcinogens into the air, groundwater, or soil,” she added.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Wiley, via EurekAlert!, a service of AAAS. …

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Buying a used car? Be sure to flatter the seller

July 26, 2013 — Consumers set high prices when selling their possessions because they feel threatened, according to a new study in the Journal of Consumer Research.”When consumers consider selling a product they own, they feel threatened by the impending loss. In order to counter this threat, they increase the product’s value,” write authors Promothesh Chatterjee (University of Kansas), Caglar Irmak (University of Georgia), and Randall L. Rose (University of South Carolina).Due to a phenomenon called the “endowment effect,” consumers seek much higher prices when selling a product they own than they would be willing to pay to purchase the same product.In one study, consumers were assigned either a seller or buyer role and presented with a coffee mug. Sellers were told they could keep the mug or sell it, while buyers were asked to evaluate the mug. Then, both sellers and buyers were shown a series of words on a computer screen consisting of threat-related words (endanger), neutral words (wood), and non-words (tlun). Sellers responded to threat-related words much more quickly than buyers, and this difference in their response time led to significantly higher selling prices compared to buying prices.Consumers should be aware that sellers can feel threatened when parting with even the most mundane possessions. Complimenting or flattering a seller can make them feel less threatened and lead them to lower their selling prices.”Affirming a seller leads to elimination of the endowment effect. Buyers may want to affirm sellers to make them feel less threatened by the loss of a possession and therefore willing to set lower prices. Next time you are buying a second-hand car, for example, you may want to start the negotiation by telling the car owner what a wonderful family she has,” the authors conclude.

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Flow restrictors may reduce young children’s accidental ingestion of liquid medications

July 25, 2013 — n the US, child-resistant packaging for most medications has contributed to the prevention of thousands of pediatric deaths. Nevertheless, over 500,000 calls are made to poison control centers each year after accidental ingestion of medications by young children, and the number of emergency department visits for unsupervised medication ingestions is rising. In a new study scheduled for publication in The Journal of Pediatrics, researchers studied whether adding flow restrictors to bottles can limit the amount of liquid medication a child could access even if child-resistant caps are missing or improperly closed.Standard child-resistant packaging is designed to prevent or delay young children from opening bottles, giving caregivers reasonable time to intervene. However, in order for the packaging to work effectively, “Caregivers must correctly resecure the cap after each and every use. If the cap is not correctly resecured, children can open and drink whatever medication is in the bottle,” according to Daniel S. Budnitz, MD, MPH, and colleagues from the Centers for Disease Control and Prevention, Emory University, and the Georgia Poison Center.To address a potential second line of defense, the researchers studied whether flow restrictors (adapters added to the neck of a bottle to limit the release of liquid) had any effect on the ability of children to remove test liquid, as well as how much they were able to remove in a given amount of time. 110 children, aged 3-4 years, participated in two tests. In one test, the children were given an uncapped medication bottle with a flow restrictor, and in the other test, the children received either a traditional bottle without a cap or with an incompletely-closed child-resistant cap. For each test, children were given 10 minutes to remove as much test liquid as possible.Within 2 minutes, 96% of bottles without caps and 82% of bottles with incompletely-closed caps were emptied. In contrast, none of the uncapped bottles with flow restrictors were emptied before 6 minutes, and only 6% of children were able to empty bottles with flow restrictors within the 10-minute test period. …

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Is a common food fungus worsening the AIDS epidemic?

July 23, 2013 — A type of fungus coating much of the stored corn, wheat, rice and nuts in developing countries may be quietly worsening the AIDS epidemic, according to a paper published today in the World Mycotoxin Journal.Kept in sacks piled in barns and warehouses, food stores in countries near the equator are contaminated by Aspergillus flavus and A. parasiticus, fungi that produce a toxic substance called aflatoxin. About 4.5 billion people worldwide are exposed to aflatoxin at unsafe levels, and chronic exposure has been linked to liver damage and related cancers; but its role in the spread of infectious disease could make it even more deadly.”Our work suggests study that aflatoxin exposure may be taking an even greater toll in areas where millions are infected with HIV, including Africa and Asia, the latter with a fast-growing HIV population and rice storage areas contaminated by fungi,” said Pauline, Jolly, Ph.D., professor in the Department of Epidemiology within the School of Public Health at the University of Alabama at Birmingham (UAB). Strict regulation and monitoring minimize exposure in the United States.Jolly and her colleagues recruited 314 HIV-positive people who were not yet on antiretroviral therapy for the study in Kumasi, Ghana. They divided patients into four groups based on their level of aflatoxin exposure and found that those in the highest exposure group were 2.6 times more likely to have a high HIV viral load than those in the lowest exposure group. Higher viral load translates into higher rates of HIV transmission and the potential for earlier progression to the opportunistic infections of AIDS.”Previous studies by our team had looked at the possible interaction of aflatoxin and HIV on immune suppression, and this study examined twice as many patients as previous studies,” said Jolly, the study’s corresponding author. “It also was structured to eliminate factors such as opportunistic infections and antiviral combination therapy in clarifying the relationship between aflatoxin exposure and HIV for the first time.”Leading theories suggest that the fungal toxin may suppress the immune system by reducing the production of certain immune cells or the proteins that activate them. The toxin also may increase the expression of genes that result in more copies of the virus, but more study is needed to confirm the mechanisms.Along with Jolly, the study authors were Seidu Inusah and Baogen Lu, M.D., in the UAB departments of Biostatistics and Epidemiology; William Ellis, Ph.D., Kwame Nkrumah University of Science and Technology in Kumasi; Alberta Nyarko, M.D., Kumasi South Regional Hospital in Kumasi; Timothy Phillips, Ph.D., Texas A & M University Department of Veterinary Integrative Biosciences; and Jonathan Williams, Ph.D., University of Georgia College of Agricultural and Environmental Science.This research was supported by a grant by the U.S. Agency for International Development (LAG-G-00-96-90013-00) plus support from the Centers for Disease Control and Prevention and National Institute on Minority Health and Health Disparities.”We have done a series of studies now confirming a link between HIV viral load and aflatoxin exposure, but the problem has not yet been recognized or addressed,” said Jolly, an HIV immunologist who does most of her work in Ghana. “While this study was larger than our previous study, a fungal contribution to HIV transmission will only be proved once and for all by larger randomized studies for which there now is no funding. …

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A new weapon against stroke

July 23, 2013 — One of regenerative medicine’s greatest goals is to develop new treatments for stroke. So far, stem cell research for the disease has focused on developing therapeutic neurons — the primary movers of electrical impulses in the brain — to repair tissue damaged when oxygen to the brain is limited by a blood clot or break in a vessel. New UC Davis research, however, shows that other cells may be better suited for the task.Published today in the journal Nature Communications, the large, collaborative study found that astrocytes — neural cells that transport key nutrients and form the blood-brain barrier — can protect brain tissue and reduce disability due to stroke and other ischemic brain disorders.”Astrocytes are often considered just ‘housekeeping’ cells because of their supportive roles to neurons, but they’re actually much more sophisticated,” said Wenbin Deng, associate professor of biochemistry and molecular medicine at UC Davis and senior author of the study. “They are critical to several brain functions and are believed to protect neurons from injury and death. They are not excitable cells like neurons and are easier to harness. We wanted to explore their potential in treating neurological disorders, beginning with stroke.”Deng added that the therapeutic potential of astrocytes has not been investigated in this context, since making them at the purity levels necessary for stem cell therapies is challenging. In addition, the specific types of astrocytes linked with protecting and repairing brain injuries were not well understood.The team began by using a transcription factor (a protein that turns on genes) known as Olig2 to differentiate human embryonic stem cells into astrocytes. This approach generated a previously undiscovered type of astrocyte called Olig2PC-Astros. More importantly, it produced those astrocytes at almost 100 percent purity.The researchers then compared the effects of Olig2PC-Astros, another type of astrocyte called NPC-Astros and no treatment whatsoever on three groups of rats with ischemic brain injuries. The rats transplanted with Olig2PC-Astros experienced superior neuroprotection together with higher levels of brain-derived neurotrophic factor (BDNF), a protein associated with nerve growth and survival. …

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High tooth replacement rates in largest dinosaurs contributed to their evolutionary success

July 17, 2013 — Rapid tooth replacement by sauropods, the largest dinosaurs in the fossil record, likely contributed to their evolutionary success, according to a research paper by Stony Brook University paleontologist Michael D’Emic, PhD, and colleagues. Published in PLOS ONE, the study also hypothesizes that differences in tooth replacement rates among the giant herbivores likely meant their diets varied, an important factor that allowed multiple species to share the same ecosystems for several million years.Paleontologists have long wondered how sauropods digested massive amounts of foliage that would have been necessary for their immense sizes. In “Evolution of high tooth replacement rates in sauropod dinosaurs,” the team of paleontologists reveal that their new research into the microscopic structure of sauropod teeth shows the dinosaurs formed and replaced teeth faster than any other type of dinosaurs — more like sharks and crocodiles — and this process kept teeth fresh given the immense amount of wear they underwent from clipping off enormous volumes of food required for them.”The microscopic structure of teeth and bones records aspects of an animal’s physiology, giving us a window into the biology of long-extinct animals,” said Dr. D’Emic, Research Instructor in the Department of Anatomical Sciences at Stony Brook University School of Medicine. “We determined that for the gigantic sauropods, each tooth took just a few months to form. Effectively, sauropods took a ‘quantity over quality’ approach.”Dr. D’Emic explained that unlike mammals and some other dinosaurs, sauropods did not chew their food. They snipped food into smaller pieces before swallowing.”At least twice during their evolution, sauropods evolved small, peg-like teeth that formed and replaced quickly,” said Dr. D’Emic. “This characteristic may have led to the evolutionary success of sauropods.”The team developed a novel method to estimate sauropod tooth formation and replacement rate without destructively sampling the teeth by making microscopic sections. …

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Steering stem cells with magnets

July 16, 2013 — Magnets could be a tool for directing stem cells’ healing powers to treat conditions such as heart disease or vascular disease.By feeding stem cells tiny particles made of magnetized iron oxide, scientists at Emory and Georgia Tech can then use magnets to attract the cells to a particular location in the body after intravenous injection.The results are published online in the journal Small and will appear in an upcoming issue.The paper was a result of collaboration between the laboratories of W. Robert Taylor, MD, PhD, and Gang Bao, PhD. Taylor is professor of medicine and biomedical engineering and director of the Division of Cardiology at Emory University School of Medicine. Bao is professor in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. Co-first authors of the paper are postdoctoral fellows Natalia Landazuri, PhD, and Sheng Tong, PhD. Landazuri is now at the Karolinska Institute in Sweden.The type of cells used in the study, mesenchymal stem cells, are not embryonic stem cells. Mesenchymal stem cells can be readily obtained from adult tissues such as bone marrow or fat. They are capable of becoming bone, fat and cartilage cells, but not other types of cell such as muscle or brain. They secrete a variety of nourishing and anti-inflammatory factors, which could make them valuable tools for treating conditions such as cardiovascular disease or autoimmune disorders.Magnetized iron oxide nanoparticles are already FDA-approved for diagnostic purposes with MRI (magnetic resonance imaging). …

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Distinctive brain blood flow patterns associated with sexual dysfunction

July 16, 2013 — Premenopausal women who aren’t interested in sex and are unhappy about this reality have distinctive blood flow patterns in their brains in response to explicit videos compared to women with normal sexual function, researchers report.A study of 16 women — six with normal sexual function and 10 with clear symptoms of dysfunction — showed distinct differences in activation of brain regions involved in making and retrieving memories, and determining how attentive they are to their response to sexual stimuli, researchers report in the journal Fertility and Sterility.Up to 20 percent of women may have this form of sexual dysfunction, called hypoactive sexual desire disorder, for which there are no proven therapies, said Dr. Michael P. Diamond, Chairman of the Department of Obstetrics and Gynecology at the Medical College of Georgia at Georgia Regents University.Researchers hope that a clearer understanding of physiological differences in these women will provide novel therapy targets as well as a method to objectively assess therapies, said Diamond, the study’s senior author.”There are site-specific alterations in blood flow in the brains of individuals with hypoactive sexual disorders versus those with normal sexual function,” Diamond said. “This tells me there is a physiologic means of assessing hypoactive sexual desire and that as we move forward with therapeutics, whether it’s counseling or medications, we can look to see whether changes occur in those regions.”Viagra, developed in the 1990s as way to increase the heart rate of sick babies, was approved by the Food and Drug Administration in 1998 to also treat male impotence, a major cause of sexual dysfunction. While several more options for men have been developed since, no FDA-approved options are available for women experiencing hypoactive sexual desire, Diamond said. He notes that a possible critical flaw in developing and evaluating therapies for women may be the inability to objectively measure results, other than with a woman’s self-reporting of its impact on sexual activity.Years ago, Diamond, a reproductive endocrinologist, became frustrated by the inability to help these women. In fact, many women did not bother discussing the issue with their physicians, possibly because it’s an awkward problem with no clear solutions, he said.While still at Wayne State University, he and his colleagues began looking for objective measures of a woman’s sexual response, identifying sexually explicit film clips, then using functional magnetic resonance imaging, which measures real-time brain activation in response to a stimulus, to look at responses.Their latest study links acquired hypoactive sexual desire disorder to a distinct pattern of blood flow in the brain, with significant activation of cortical structures involved in attention and reflection about emotion and mental state. Researchers noted that paying more attention to response to sexual stimuli already is implicated in sexual dysfunction. They also note activation of the anterior cingulate gyrus, an area involved in a broad range of emotions including homeostasis, pain, depression, and apathy. Another key area was the amygdala, which has a central role in processing emotion, learning, and memory.Women with normal sexual function showed significantly greater activation of areas such as the right thalamus — a sort of relay station for handling sensory and motor input — that also plays a role in sexual arousal. …

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