Archive for November 2009
Researchers are now one step closer to being able to use skin tissue derived from stem cells for the treatment of burn victims, according to a study published November 21 in The Lancet.
By tweaking the way the cells are grown in a Petri dish, a team of scientists at the Institute for Stem Cell Therapy and Exploration of Monogenic Diseases near Paris, France, was able to coax human embryonic stem cells into becoming multilayered skin tissue. The group also grafted the human stem cell-derived skin onto the backs of five mice. The foreign tissue grew well for at least 12 weeks, suggesting that it could at least be a safe temporary solution until skin tissue from a patient's body, aka autologous graft tissue, is ready.
Posted November 28, 2009on:
Scientists at the California Institute of Technology (Caltech) have uncovered evidence of a primitive emotion-like behavior in the fruit fly, Drosophila melanogaster.
Their findings, which may be relevant to the relationship between the neurotransmitter dopamine and attention deficit hyperactivity disorder (ADHD), are described in the December issue of the journal Neuron.
The Drosophila brain contains only about 20,000 neurons and has long been considered a powerful system with which to study the genetic basis of behaviors such as learning and courtship, as well as memory and circadian rhythms. What hasn’t been clear is whether the Drosophilabrain also could be used to study the genetic basis of “emotional” behaviors. Read the rest of this entry »
Ghrelin, a hormone produced in the stomach, may be used to boost resistance to, or slow, the development of Parkinson’s disease, Yale School of Medicine researchers report in a study published in a recent issue of the Journal of Neuroscience. Read the rest of this entry »
Posted November 28, 2009on:
Patients should avoid using the stomach acid reducer Prilosec/Prilosec OTC (omeprazole) with the anti-clotting drug Plavix (clopidogrel), the U.S. Food and Drug Administration warned on Nov. 17.
New data suggest that when patients take both Prilosec and Plavix, Plavix’s ability to block platelet aggregation (anti-clotting effect) may be reduced by about half.
“Both of these drugs, when used properly, provide significant benefits to patients.” said Mary Ross Southworth, Pharm.D., of the Division of Cardiovascular and Renal Products in the FDA’s Center for Drug Evaluation and Research. “However, patients at risk for heart attacks or strokes who use Plavix to prevent platelet aggregation will not get the full effect of this medicine if they are also taking Prilosec.”
Plavix is used to prevent blood clots that could lead to heart attacks or strokes in at-risk patients. Omeprazole, the active ingredient of Prilosec and Prilosec OTC, is a proton pump inhibitor (PPI) used to reduce the production of stomach acid and prevent stomach irritation.
Last year, researchers at the Rush University Medical Center in Chicago showed that human cells in culture could synchronize their internal chemical processes even though they were mechanically, chemically, and electrically isolated from one another. The cells, it seemed, were communicating through the exchange of photons.Various other groups have shown similar effects. Many cells seems to produce optical and UV photons at about 10 photons per square cm/s, a rate that cannot be explained by ordinary thermodynamic emissions. Other evidence indicates that this form of optical communication can increase the rate of mitosis in cells by up to 50 percent.So how do they do it? Today Sergei Mayburov at the Lebedev Institute of Physics in Moscow puts forward the idea that optical communication is a natural process in many cells that can be explained by the way we already know many cells to function.
On the skin’s surface, bacteria are abundant, diverse and constant, but inflammation is undesirable. Research at the University of California, San Diego School of Medicine now shows that the normal bacteria living on the skin surface trigger a pathway that prevents excessive inflammation after injury. Read the rest of this entry »
Whitehead researchers have developed a new type of genetic screen for human cells to pinpoint specific genes and proteins used by pathogens, according to their paper in Science.
In most human cell cultures genes are present in two copies: one inherited from the father and one from the mother. Gene inactivation by mutation is therefore inefficient because when one copy is inactivated, the second copy usually remains active and takes over.
What are the bare essentials of life, the indispensable ingredients required to produce a cell that can survive on its own? Can we describe the molecular anatomy of a cell, and understand how an entire organism functions as a system? In three papers published back-to-back today in Science, they provide the first comprehensive picture of a minimal cell, based on an extensive quantitative study of the biology of the bacterium that causes atypical pneumonia, Mycoplasma pneumoniae. The study uncovers fascinating novelties relevant to bacterial biology and shows that even the simplest of cells is more complex than expected.
Viruses multiply incredibly quickly once they've infected their victim–so fast that antiviral medications such as Tamiflu are only effective if given during the first few days of an infection. After that, the viral load is just too high for a single drug to fight off. But researchers are working on a treatment for the H1N1 virus (or swine flu) that uses a different approach. Rather than disabling the virus with a drug, they're creating a vaccine that can activate and steer a patient's own immune cells to attack the invader
By modifying a single gene, scientists have made Hobbie-J the smartest rat in the world, a new study says.
A similar gene tweak might boost human brainpower too, but scientists warn that there is such a thing as being too smart for your own good
For years scientifically smartened rats have skittered through movies and books such as Flowers for Algernon and The Secret of NIMH. But Hobbie-J is anything but fiction.
The lab rat can remember objects three times longer than her smartest kin, the study says. Thanks largely to this memory boost, she's also much better at solving complex tasks, such as traveling through mazes using only partial clues to find rewards—a key method for measuring rat intelligence.
Researchers have demonstrated a tiny chip based on silicon that could be used to diagnose dozens of diseases.
A tiny drop of blood is drawn through the chip, where disease markers are caught and show up under light.
The device uses the tendency of a fluid to travel through small channels under its own force, instead of using pumps.
The design is simpler, requires less blood be taken, and works more quickly than existing “lab on a chip” designs, the team report in Lab on a Chip.
Posted November 22, 2009on:
More than half a million people in the U.S. have died from HIV infection, and more than a million currently live with the virus, but a relative handful of people infected with HIV never get treatment for it and never get sick from it. The immune systems of this small population—perhaps 50,000 Americans—somehow control the virus for long periods of time. Of course, there is typically a bell curve of response to any disease, but figuring out how these people control the virus is one of the most vexing mysteries of the AIDS pandemic. Solving it might unlock new ways to prevent and treat HIV infection, and now several research teams are going after the answer.
Drugs that boost the chemical messenger norepinephrine in the brain have been shown to alleviate cognitive problems in mice engineered to mirror Down syndrome. The findings, published today in the journal Science Translational Medicine, suggest a new approach to treating the disorder. Several existing drugs can boost the chemical or mimic its effects, though none have yet been tested in patients with Down syndrome.
Next time you're stuck in traffic, try deep breathing exercises instead of honking your horn. It could save your life.
Researchers found that people who have a positive attitude during stressful events are 22% less likely to have a fatal or nonfatal heart attack than those who have negative attitudes.
There is new evidence that folic acid, taken in large doses, may promote some cancers.
Heart patients in Norway who took folic acid and vitamin B12 supplements were found to have a slightly increased risk for cancer and death from all causes, compared to heart patients who did not take the supplements in a study published in TheJournal of the American Medical Association.
People constantly make complex decisions, from the more mundane—which restaurant to go to for dinner or which movie to go see—to the more profound—whether to have kids or not. Now, a new study published online on November 12th in Current Biology, a Cell Press publication, confirms an important role for the brain chemical dopamine in how people make such life choices, by influencing our expectations of the pleasure associated with their outcomes. Read the rest of this entry »
Short-term memory may depend in a surprising way on the ability of newly formed neurons to erase older connections. That’s the conclusion of a report in the November 13th issue of the journal Cell, a Cell Press publication, that provides some of the first evidence in mice and rats that new neurons sprouted in the hippocampus cause the decay of short-term fear memories in that brain region, without an overall memory loss. Read the rest of this entry »
Finding a cure for amyotrophic lateral sclerosis (ALS)–also known as Lou Gehrig's disease–has been a frustrating and elusive quest. Even after decades of research, the biological roots of ALS are only partially understood. Now a new form of treatment offers fresh hope.
Trophos, a company based in Marseilles, France, has discovered a drug compound that appears to protect neurons from the effects of ALS, a rapidly debilitating degeneration of motor neurons in the brain and spinal cord. These effects lead to muscle atrophy and, ultimately, complete loss of motor control. The company's researchers have found that a compound named olesoxime promotes survival and regeneration of neurons deprived of neurotrophic factors–proteins essential for maintaining healthy neurons. This deprivation is similar to what occurs in the neurons of ALS patients.
Posted November 17, 2009on:
While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well – and that inadequate levels of the vitamin may significantly increase a person’s risk of stroke, heart disease, and death, even among people who’ve never had heart disease. Read the rest of this entry »
Chilling the brains of people in cardiac arrest as they are rushed to the hospital improves the chances they will survive — and without brain damage, researchers report.
In cardiac arrest, the heart stops beating, cutting off the blood supply to the body and brain. Even if a patient can be resuscitated, brain damage often results.
But several years ago, researchers found that lowering the body temperature of a newly revived cardiac arrest patient in the hospital can make a big difference.
The new approach, already in use in Europe, extends the technique to people who suffer cardiac arrest outside the hospital.
“Cooling the brain fast and really early is critical to success,” says Maaret Castrén, MD, of the Karolinska Institute in Stockholm.
Posted November 17, 2009on:
Cancer researchers of the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch have gained new insights into how cells react to DNA damage. Dr. Michael Stilmann, Dr. Michael Hinz and Professor Claus Scheidereit have shown that the protein PARP-1, which detects DNA damage within seconds, activates the transcription factor NF-kappaB, a well-known regulator of gene expression. NF-kappaB triggers a survival program, which blocks programmed cell death. The activation of NF-kappaB is thought to be one of the potential causes for tumor cell resistance to chemo and radiation therapy
Viruses are microscopically sized parasites. They plant their genes in the cells of their victim in order to ‘reprogram’ them. The infected cells then no longer produce what they need to live, making lots of new viruses instead.
Luckily, in most cases this hostile takeover does not go unnoticed. This is ensured by the cells’ own sensors that recognise alien genetic material. One of them is RIG-I. When RIG-I encounters virus genes, it ensures that the body releases interferon. The interferon then in turn puts killer cells on combat standby, which then destroy the infected cells. Read the rest of this entry »
A team led by Yale University scientists has developed a new approach to studying how immune cells chase down bacteria in our bodies. Their findings are described in the November 15 issue of Nature MethodsAdvanced Online Publication.
A new type of immune cell that can be out of control in certain chronic inflammatory diseases, worsening the symptoms of conditions like psoriasis and asthma, is described for the first time this week in the Journal of Clinical Investigation.
The authors of the study, from Imperial College London, the Istituto Dermopatico dell’Immacolata in Rome and the Center of Allergy and Environment (ZAUM) in Munich, hope their discovery could lead to new treatments for these diseases that would bring the cells under control.
The new cell described in the study, called a Th22 cell, is a kind of T-helper cell. These cells are white blood cells that help to activate other immune cells when the body is infected by a pathogen, such as a virus or bacterium. They also control inflammation in the body to help fight off infection. Read the rest of this entry »
Some men with low levels of vitamin D in their blood are at particularly high risk of developing heart disease and weakened bones that can lead to osteoporosis, researchers report.
In a study of more than 1,000 men, those with low levels of both vitamin D and the sex hormone estrogen were at significantly increased risk of having cardiovascular disease, says study head Erin Michos, MD, a cardiologist at Johns Hopkins.
Tiny insects could be as intelligent as much bigger animals, despite only having a brain the size of a pinhead, say scientists at Queen Mary, University of London.
“Animals with bigger brains are not necessarily more intelligent,” according to Lars Chittka, Professor of Sensory and Behavioural Ecology at Queen Mary’s Research Centre for Psychology and University of Cambridge colleague, Jeremy Niven. This begs the important question: what are they for?
Couples who bring thoughtful words to a fight release lower amounts of stress-related proteins, suggesting that rational communication between partners can ease the impact of marital conflict on the immune system.
“Previous research has shown that couples who are hostile to each other show health impairments and are at greater risk of disease,” said Jennifer Graham, assistant professor of biobehavioral health, Penn State. “We wanted to know if couples who use thoughtfulness and reasoning in the midst of a fight incur potential health benefits.”
Individuals in a stressful situation — as in a troubled relationship — typically have elevated levels of chemicals known as cytokines. These proteins are produced by cells in the immune system and help the body mount an immune response during infection. However, abnormally high levels of these proteins are linked to illnesses such as cardiovascular disease, type-2 diabetes, arthritis and some cancers. Read the rest of this entry »
A prescription version of niacin beat out a blockbuster cholesterol-lowering drug in slowing the buildup of plaque in artery walls, researchers report.The study pitted extended-release niacin, sold as Niaspan, which works by boosting levels of HDL “good” cholesterol, against ezetimibe. Ezetimibe, sold as Zetia, lowers levels of LDL “bad” cholesterol.The findings are the second recent setback for Zetia. Last year, another study showed that Vytorin, a combination of Zetia and Zocor, worked no better than Zocor alone.
Even moderate alcohol consumption of more than two drinks a week may raise the risk of cancer, according to a new study, despite past research suggesting that light drinking can benefit your health. So whats the truth?A new study reveals that even moderate drinking can raise a womans risk.The latest piece of evidence on the risks of drinking alcohol comes from researchers at Oxford University who studied more than 1.2 million women in the United Kingdom. They found that drinking alcohol may account for about 13 percent of all breast , liver, rectal and upper digestive tract cancers in wom
The human brain is made up of 100 billion neurons — live wires that must be kept in delicate balance to stabilize the world’s most magnificent computing organ. Too much excitement and the network will slip into an apoplectic, uncomprehending chaos. Too much inhibition and it will flatline. A new mathematical model describes how the trillions of interconnections among neurons could maintain a stable but dynamic relationship that leaves the brain sensitive enough to respond to stimulation without veering into a blind seizure.
Molecules designed to slow the production of toxic byproducts in the eye by making it less sensitive to light are now being tested in patients with macular degeneration, the leading cause of blindness in people age 50 and older. If successful, the compounds would provide a much needed therapy for the disease, which affects more than 15 million people in the United States.
Many Americans do not think twice about taking medicines to prevent heart disease and stroke. But cancer is different. Much of what Americans do in the name of warding off cancer has not been shown to matter, and some things are actually harmful. Yet the few medicines proved to deter cancer are widely ignored.
A high-fat, high-sugar diet can quickly and dramatically change the population of microbes living in the digestive tract, according to a new study of human gut bugs transplanted into mice.
Trillions of microbes live inside the human gut, and one of their functions is to process parts of foods that we can't digest on our own. Recent studies have suggested that certain populations of microbes may be associated with obesity.
A telltale signature of consciousness has been detected that takes us a step closer to disentangling the brain activity underlying conscious and unconscious brain processes.
It turns out that there is a similar pattern of neural activity each time we become conscious of the same picture, but not if we process information from the image unconsciously. These contrasting patterns of activity can now be detected via brain scans, and could one day help determine if patients with brain damage are conscious. They might even be used to probe consciousness in animals.
It is often thought of as one of the things that make humans unique. Now, researchers are uncovering the suite of genes that gave us our gift of the gab.
All of them appear to be controlled by a master-switch gene called Foxp2. When inactive, this gene causes severe speech and language problems in humans. Although other animals have versions of Foxp2, in 2002 a German team identified two small alterations in the protein the human Foxp2 produces that are not carried by our closest living relative, the chimpanzee. This suggested that the human version of Foxp2 may function differently, and be a key element in our unique linguistic abilities.
Earlier this year, Wolfgang Enard's team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, spliced this human version of Foxp2 into mice. The mice didn't start speaking, but their sub-sonic vocaliszations changed, as did the shape and activity of neurons in a brain area that goes awry in people with Foxp2-related language disorders.
Those stress-induced chocolate cravings may be justified after all. A new study shows that eating dark chocolate may lower levels of stress hormones in people feeling stressed out.Researchers found that eating the equivalent of one average-sized dark chocolate candy bar 1.4 ounces each day for two weeks reduced levels of the stress hormone cortisol as well as the “fight-or-flight” hormones known as catecholamines in highly stressed people.
Diet soda may help keep your calories in check, but drinking two or more diet sodas a day may double your risk of declining kidney function, a new study shows.Women who drank two or more diet sodas a day had a 30% drop in a measure of kidney function during the lengthy study follow-up, according to research presented Saturday at the annual meeting of the American Society of Nephrology in San Diego.
As many as 100,000 cases of cancer could be prevented in the U.S. each year if Americans get rid of their excess body fat.
That’s according to estimates released by the American Institute for Cancer Research. The estimates suggest that heart disease, diabetes, and joint problems aren’t the only illnesses in which rampant obesity is causing havoc.
The group says overweight and obesity could be the cause of more than 6% of all the estimated 1.6 million cancer cases diagnosed in the U.S. each year.
A study in mice has hinted at the impact that early life trauma and stress can have on genes, and how they can result in behavioural problems.
Scientists described the long-term effects of stress on baby mice in the journal Nature Neuroscience.
Stressed mice produced hormones that “changed” their genes, affecting their behaviour throughout their lives.
Researchers have used a modified AIDS virus to halt a devastating brain disease in two young boys. The treatment, in which the virus delivered a therapeutic gene, marks the first time gene therapy has been successfully used against X-linked adrenoleukodystrophy (ALD)–a disorder that is always fatal if untreated. With this proof of principle, scientists hope versions of the AIDS virus engineered to carry different genes can now be applied to a variety of other diseases.
As many as 100,000 cases of cancer could be prevented in the U.S. each year if Americans get rid of their excess body fat.Thats according to estimates released by the American Institute for Cancer Research. The estimates suggest that heart disease, diabetes, and joint problems arent the only illnesses in which rampant obesity is causing havoc.The group says overweight and obesity could be the cause of more than 6% of all the estimated 1.6 million cancer cases diagnosed in the U.S. each year.
It’s Alive! Researchers at Harvard University and Massachusetts General Hospital have succeeded in taking embryonic stem cells from mice and growing cardiovascular tissue. The research team, led by Dr. Kenneth Chien, believes that a similar process may one day serve to repair cardiac damage in humans. The work was recently published in the journal Science. You can see the mouse heart cells beating at different speeds in the video from Boston.com after the break.
In a small manufacturing space on a Cambridge, MA, street dotted with biotech companies, Greg Troiano tinkers with a series of gleaming metal vats interweaved with plastic tubes. The vats are designed to violently shake a mix of chemicals into precise nanostructures, and Troiano’s task, as head of process development at start-up BIND Biosciences, is to make kilograms of the stuff–a novel drug-infused nanoparticle. The company hopes the new drug-delivery system will diminish the side effects of chemotherapy while increasing its effectiveness in killing cancer.
By forcing bacteria to evolve in ever-changing conditions, scientists have induced a behavior in which colonies formed by microbes with identical genes take radically different forms, as if one sibling in a set of identical quadruplets could sprout gills.
Technically known as “stochastic switching between phenotypic states” — or, more conversationally, hedging your bets — the ability may have been critical to the success of primitive forms of life.
Eyeball your food a little longer if you’re looking to shed some pounds, because wolfing it down too fast may make you prone to overeat, a new study shows.
So savor those aromas, relish the meal’s presentation, and don’t just dig in like you’ve got to finish it off in a hurry, researchers report in The Journal of Clinical Endocrinology & Metabolism.
A specific type of T helper cell awakens the immune system to the stealthy threat of cancer and triggers an attack of killer T cells custom-made to destroy the tumors, scientists from The University of Texas M. D. Anderson Cancer Center report in the early online edition of the journal Immunity. Read the rest of this entry »
Saturated fats have a deservedly bad reputation, but Johns Hopkins scientists have discovered that a sticky lipid occurring naturally at high levels in the brain may help us memorize grandma’s recipe for cinnamon buns, as well as recall how, decades ago, she served them up steaming from the oven.
The Hopkins team, reporting Oct. 29 in Neuron, reveals how palmitate, a fatty acid, marks certain brain proteins – NMDA receptors – that need to be activated for long-term memory and learning to take place. The fatty substance directs the receptors to specific locations in the outer membrane of brain cells, which continually strengthen and weaken their connections with each other, sculpting and resculpting new memory circuits. Read the rest of this entry »
Scientists at the University of Bonn have discovered a previously unknown fruit fly gene that controls the metabolism of fat. Larvae in which this gene is defective lose their entire fat reserves. Therefore the researchers called the gene ‘schlank’ (German for ‘slim’). Mammals carry a group of genes that are structurally very similar to ‘schlank’. They possibly take on a similar function in the energy metabolism. The scientists therefore have hopes in new medicines with which obesity could be fought. Read the rest of this entry »
The immune system’s T cells have the unique responsibilities of being both jury and executioner. They examine other cells for signs of disease, including cancers or infections, and, if such evidence is found, rid them from the body. Precisely how T cells shift so swiftly from one role to another, however, has been a mystery.
In a new study, investigators at Dana-Farber Cancer Institute, Harvard Medical School, and the Massachusetts Institute of Technology used an array of techniques — including “optical tweezers” that exploit laser light to press molecules against surface structures found on T cells — to find out what operates the switch. Their answer: sheer mechanical force. Hence, the T cell receptor is a mechanosensor.
Posted November 4, 2009on:
Researchers at the University of Warwick have identified a particular combination of health problems that can double the risk of heart attack and cause a three-fold increase in the risk of mortality.
The team, led by Assistant Clinical Professor of Public Health at Warwick Medical School Dr Oscar Franco, has discovered that simultaneously having obesity, high blood pressure and high blood sugar are the most dangerous combination of health factors when developing metabolic syndrome. Read the rest of this entry »