Archive for July 2011
Distinguishing between other peoples voices may seem like a trivial task. However, if those people are speaking a language you dont understand, it becomes much harder. Thats because you rely on individuals differences in pronunciation to help identify them. If you dont understand the words they are saying, you dont pick up on those differences.
That ability to process the relationship between sounds and their meanings, also known as phonology, is believed to be impaired in people with dyslexia. Therefore, neuroscientists at MIT theorized that people with dyslexia would find it much more difficult to identify speakers of their native language than non-dyslexic people.
Yale University researchers can’t tell you where you left your car keys — but they can tell you why you can’t find them
A new study published July 27 in the journal Nature shows the neural networks in the brains of the middle-aged and elderly have weaker connections and fire less robustly than in youthful ones. Intriguingly, the research suggests that this condition is reversible.
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Posted July 28, 2011on:
Researchers at Stanford University School of Medicine have been able to switch on, and then switch off, social-behavior deficits in mice that resemble those seen in people with autism and schizophrenia, thanks to a technology that allows scientists to precisely manipulate nerve activity in the brain. In synchrony with this experimentally induced socially aberrant behavior, the mice exhibited a brain-wave pattern called gamma oscillation that has been associated with autism and schizophrenia in humans, the researchers say.
The findings, to be published online in Nature on July 27, lend credence to a hypothesis that has been long floated but hard to test, until now. They mark the first demonstration, the researchers said, that elevating the brain’s susceptibility to stimulation can produce social deficits resembling those of autism and schizophrenia, and that then restoring the balance eases those symptoms.
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Key cells in the brain region known as the hippocampus are formed in the base of the brain late in fetal life and undertake a long journey before reaching their final destination in the center of the brain shortly after birth, according to researchers at the National Institutes of Health.
The hippocampus is involved with attention, navigation and converting short-term memories to long-term memories. Interneurons, the brain cell population the researchers studied, regulate communication between networks of brain cells. Previous research suggests that brain cell networks in the hippocampus may be disrupted in developmental disorders, including autism, as well as in epilepsy, Alzheimer’s disease and schizophrenia.
“The hippocampus seems to be at the crossroads of many disorders affecting the brain,” said Chris McBain, Ph.D., chief of the Laboratory of Cellular and Synaptic Neurophysiology at the NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD). “With these findings, we can begin to understand how proper communication is established in the brain and to investigate why sometimes it breaks down in this critical area.”
A Step Closer to Personalized Medicine: Improving Gene Therapy To Treat a Devastating Genetic Disease
Posted July 27, 2011on:
Recent advances in adult stem cell research could change the way doctors treat a host of debilitating diseases. At NIAID, scientists are exploring novel ways to convert adult tissue into more primitive stem cells and then use these cells to treat chronic granulomatous disease (CGD), an inherited disease of the immune system. The most exciting part of NIAID’s research? The treatment cells come from the patient. No donors are necessary.
Neutrophil from a blood smear magnified 100X
Credit: Wikimedia Commons
Most health insurers are wary of genetics because, in most cases, it’s not yet clear how a particular genetic variation influences an individual’s health, or whether it should affect their care.
Now Kaiser Permanente, the nation’s largest nonprofit health plan, has announced that it’s finished the first phase of a massive project to compile genetic, medical, and environmental information for 100,000 of its members. Researchers also analyzed the length of participants’ telomeres—a molecule structure at the tip of the chromosome that has been linked to aging. This represents the largest telomere study to date.
The resulting data, gathered in collaboration with the University of California, San Francisco, will soon be available to outside researchers who study how different genetic and environmental factors influence disease. It took about 15 months for the team to collect and analyze the genomes of 100,000 people ranging in age from 18 to 107. The team used gene microarrays—small chips designed to quickly detect hundreds of thousands of genetic variations across the genome.
Posted July 26, 2011on:
For modern biologists, the ability to capture high-quality, three-dimensional (3D) images of living tissues or organisms over time is necessary to answer problems in areas ranging from genomics to neurobiology and developmental biology. The better the image, the more detailed the information that can be drawn from it. Looking to improve upon current methods of imaging, researchers from the California Institute of Technology (Caltech) have developed a novel approach that could redefine optical imaging of live biological samples by simultaneously achieving high resolution, high penetration depth (for seeing deep inside 3D samples), and high imaging speed.
The unique physiology of the human liver means that the toxicity of some candidate drugs is not picked up during preclinical tests in animals. But mice implanted with miniature human livers can mimic the ways in which the human body breaks down chemical compounds, to help spot potential problems before drugs are tested in humans.
A team led by Sangeeta Bhatia, a biomedical engineer at the Massachusetts Institute of Technology in Cambridge, made 20-millimetre-long artificial human livers and implanted them into otherwise normal mice. The researchers report today in Proceedings of the National Academy of Sciences1, that the mice showed metabolism characteristic of the human liver for weeks after implantation.
Human neural stem cells are capable of helping people regain learning and memory abilities lost due to radiation treatment for brain tumors, a UC Irvine study suggests.
Research with rats found that stem cells transplanted two days after cranial irradiation restored cognitive function, as measured in one- and four-month assessments. In contrast, irradiated rats not treated with stem cells showed no cognitive improvement. Read the rest of this entry »
Posted July 23, 2011on:
Scientists at the Salk Institute for Biological Studies have developed an improved technique for generating large numbers of blood cells from a patient’s own cells. The new technique will be immediately useful in further stem cell studies, and when perfected, could be used in stem cell therapies for a wide variety of conditions including cancers and immune ailments.
Caption: Round hematopoietic (blood) cells emerge from differentiating human pluripotent stem cells.
The neurotransmitter dopamine is best known for its roles in the brain – in signaling pathways that control movement, motivation, reward, learning and memory.
Now, Vanderbilt University Medical Center investigators have demonstrated that dopamine produced outside the brain – in the kidneys – is important for renal function, blood pressure regulation and life span. Read the rest of this entry »
Posted July 23, 2011on:
Some foods are so healthy they star on every nutrition expert’s super food list. But often missing on those lists are some nutritional gems or underrated foods that don’t get the attention they deserve.
Sorting out the best foods to eat is not always easy because the choices can be daunting. Adding to the confusion are overrated foods like salads that are perceived to be good for you but can be health horrors.
Here are six foods not typically thought of as nutritional powerhouses that can definitely upgrade your diet. Getting to know them — and understanding more about the nutritional goodness of foods in general — will help you to make more informed choices that can impact your health, weight, and wallet.
Criteria for the Best Foods
In order to make our best list, foods had to be whole foods that are familiar, widely available, affordable, nutrient-rich — and most importantly, taste great. After all, what good is a super food if it isn’t a culinary delight?
A diet rich in certain omega-3 fatty acids may lower the risk of developing dementia, researchers report.
In a study of more than 2,000 older women and men followed for nearly five years, the more omega-3-rich oily fish they ate, the lower their risk of developing dementia.
The researchers looked specifically at the omega-3 fatty acids DHA (docosahexaenoic acid) and EPA (eiosapentaenoic acid), found in salmon, sardines, tuna, halibut, and mackerel.
Foods like meat and dairy products that are packed with saturated fatty acids, particularly palmitic acid, on the other hand, were liked to an increased risk of dementia, says researcher Deborah Gustafson, PhD, of the University of Gothenburg’s Institute for Neuroscience and Physiology, in Sweden. She is a visiting scientist at State University of New York-Downstate Medical Center in Brooklyn, N.Y.
The study doesn’t prove cause and effect, only that there is an association between different types of fatty acids and dementia.
Obesity is the biggest driving force behind the most common form of breast cancer in older women, say researchers.
Alcohol and then cigarettes are the next largest culprits, according to Cancer Research UK.
One in eight women in the UK develop breast cancer in their lifetime, data shows, and the majority of these tumours are “hormone sensitive” meaning their growth is fuelled by hormones.
Too much stored fat in the body raises the level of these “sex” hormones.
Artificial intelligence has been the inspiration for countless books and movies, as well as the aspiration of countless scientists and engineers. Researchers at the California Institute of Technology (Caltech) have now taken a major step toward creating artificial intelligence—not in a robot or a silicon chip, but in a test tube. The researchers are the first to have made an artificial neural network out of DNA, creating a circuit of interacting molecules that can recall memories based on incomplete patterns, just as a brain can.
“The brain is incredible,” says Lulu Qian, a Caltech senior postdoctoral scholar in bioengineering and lead author on the paper describing this work, published in the July 21 issue of the journal Nature. “It allows us to recognize patterns of events, form memories, make decisions, and take actions. So we asked, instead of having a physically connected network of neural cells, can a soup of interacting molecules exhibit brainlike behavior?”
Caption: Caltech researchers have invented a method for designing systems of DNA molecules whose interactions simulate the behavior of a simple mathematical model of artificial neural networks.
Credit: Caltech/Lulu Qian
University of Minnesota Medical School and College of Biological Sciences researchers have made a key discovery showing that male sex must be maintained throughout life.
The research team, led by Drs. David Zarkower and Vivian Bardwell of the U of M Department of Genetics, Cell Biology and Development, found that removing an important male development gene, called Dmrt1, causes male cells in mouse testis to become female cells.
A new plastic surface which overcomes the difficulties associated with growing adult stem cells has been developed, according to scientists.
Standard surfaces have proved limited for growing large amounts and retaining the stem cells’ useful characteristics.
It is hoped the discovery could lead to the creation of stem cell therapies for re-growing bone and tissue, and also for conditions such as arthritis.
The study was carried out by Glasgow and Southampton universities.
Researchers at Albert Einstein College of Medicine of Yeshiva University have developed the first fluorescent protein that enables scientists to clearly “see” the internal organs of living animals without the need for a scalpel or imaging techniques that can have side effects or increase radiation exposure.
Women who are taking a baby aspirin or two a day for their heart health may be safeguarding their brain health, too, preliminary research suggests.
In a five-year study of more than 100 older people at similar risk for heart disease, scores on a standardized test that gauges memory and other cognitive skills increased slightly in women who took 75 to 150 milligrams of aspirin a day while dropping in those who didn’t take aspirin.
Still, “this does not mean low-dose aspirin will prevent or treat Alzheimer’s disease,” says Maria Carrillo, PhD, senior director of medical and scientific relations at the Alzheimer’s Association.
“Don’t start taking aspirin on your own,” she says. Carrillo was not involved with the research, presented at the Alzheimer’s Association International Conference 2011.
Developing drugs to combat or cure human disease often involves a phase of testing with mice, so being able to peer clearly into a living mouse’s innards has real value.
But with the fluorescent dyes currently used to image the interior of laboratory mice, the view becomes murky a few millimeters under the skin.
Now Stanford researchers have developed an improved imaging method using fluorescent carbon nanotubes that create color images centimeters beneath the skin with far more clarity than conventional dyes provide. For a creature the size of a mouse, a few centimeters makes a great difference.
A new study demonstrates that higher-protein meals improve perceived appetite and satiety in overweight and obese men during weight loss.(1) According to the research, published in Obesity, higher-protein intake led to greater satiety throughout the day as well as reductions in both late-night and morning appetite compared to a normal protein diet.
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A mutant protein known to be involved in the rare premature aging condition known as progeria appears to play a role in normal aging, too, scientists report. The mechanism that triggers premature aging also seems to trigger normal cell aging.The finding is expected to offer new clues about aging.”We have learned something fundamental about the way your cells and mine are programmed to have a limited life span,” says researcher Francis Collins, MD, PhD, director of the National Institutes of Health. “It looks like it is not just a passive process.”
Medical researchers from Harvard University have created the first “living laser”; a biological cell that’s been genetically engineered to produce a visible laser beam.
Lasers need two things to generate beams. They need a gain medium that amplifies light, and an arrangement of mirrors to concentrate and align that light.
Normal lasers, ever since their invention in the 1950s, use synthetic gain materials like gases, crystals and dyes to amplify photon pulses. But professor Seok-Hyun Yun and colleague Malte Gather, instead used green fluorescent protein (GFP), which is used to make jellyfish bioluminescent, as their gain material.
Researchers at Case Western Reserve University School of Medicine have discovered a long-sought cellular factor that works to inhibit HIV infection of myeloid cells, a subset of white blood cells that display antigens and hence are important for the body’s immune response against viruses and other pathogens.
The factor, a protein called SAMHD1, is part of the nucleic acid sensing machinery within the body’s own immune system. It keeps cells from activating immune responses to the cells own nucleic acids, thus preventing certain forms of autoimmunity from developing. Read the rest of this entry »
Checking a clock may be as helpful as counting calories when it comes to controlling body weight, a new study suggests.
The study shows that people who snack after 8 p.m. have higher body mass indexes (BMIs) than people who don’t nosh at night, even though they don’t eat significantly more total daily calories.
Previous studies in animals have found that even when calories are held steady, the timing of meals and sleep and exposure to light can impact metabolism and BMI.
The new study is one of the first to explore those relationships in humans.
Posted July 3, 2011on:
Although our body’s defense mechanisms are usually capable of detecting and destroying many types of pathogens, some viruses are able to evade the immune system and make us sick. In particular, “retroviruses,” such as human immunodeficiency virus (HIV), are notorious for eluding host immune defenses and causing disease. Now, a new study published by Cell Press online on June 30th in the journal Immunity identifies a key virus-sensing mechanism that is necessary for a successful immune response against infection with this particularly deadly type of virus. The research may help to guide the future design of more effective antiretroviral vaccines. Read the rest of this entry »
Posted July 3, 2011on:
A Johns Hopkins team has discovered in young adult mice that a lone brain stem cell is capable not only of replacing itself and giving rise to specialized neurons and glia – important types of brain cells – but also of taking a wholly unexpected path: generating two new brain stem cells.
Caption: A green fluorescent protein-labeled neural stem cell clone contains the mother stem cell with neuronal and astroglial progeny within the mouse brain. Credit: Image by Michael A. Bonaguidi, Johns Hopkins Medicine.
Posted July 3, 2011on:
A trio of large-scale genome-wide association studies, or GWAS, have identified more than 15 gene variants responsible for the diversity of white blood cell counts among whites, African-Americans, and Japanese. Supported in part by the National Institutes of Health, each study examined the genomes of tens of thousands of people. Combined, the studies offer the first comprehensive analysis into why some people, and some populations, have more or fewer white blood cells than others. Read the rest of this entry »
Winning margins in the Tour de France can be tight – last year just 39 seconds separated the top two riders after more than 90 hours in the saddle. When every second counts, riders do everything possible to gain a competitive advantage – from using aerodynamic carbon fibre bikes to the very latest in sports nutrition.
Now there could be a new, completely legal and rather surprising weapon in the armoury for riders aiming to shave vital seconds off their time – beetroot juice. Read the rest of this entry »
Ever since an ordinary office inkjet printer had its ink cartridges swapped out for a cargo of cells about 10 years ago and sprayed out cell-packed droplets to create living tissue, scientists and engineers have never looked at office equipment in quite the same way. They dream of using a specialized bio-inkjet printer to grow new body parts for organ transplants or tissues for making regenerative medicine repairs to ailing bodies. Both these new therapies begin with a carefully printed mass of embryonic stem cells. And now there’s progress on getting that initial mass of stem cells printed. Read the rest of this entry »
New research has shown that feral, untrained pigeons can recognise individual people and are not fooled by a change of clothes.
Researchers, who will be presenting their work at the Society for Experimental Biology Annual Conference in Glasgow on Sunday the 3rd of July, have shown that urban pigeons that have never been caught or handled can recognise individuals, probably by using facial characteristics. Read the rest of this entry »