Archive for April 2012
Scientists have discovered that they can dramatically increase the life span of mice with progeria (premature aging disease) and heart disease (caused by Emery-Dreifuss muscular dystrophy) by reducing levels of a protein called SUN1. This research was done by A*STAR’s Institute of Medical Biology (IMB) in collaboration with their partners at the National Institute of Allergy and Infectious Diseases in the United States and the Institute of Cellular and System Medicine in Taiwan. Their findings were published in the scientific journal, Cell, on 27th April 2012 and provide an exciting lead into developing new methods to treat premature aging and heart disease.
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Aggressive pancreatic tumours may be treatable with a new class of drugs, according to Cancer Research UK
Less than one in five people with this form of cancer are still alive a year after being diagnosed.
A study, published in the journal Nature, showed that a gene was being switched off in the cancerous cells.
The reseachers said drugs were already being tested which had the potential to turn the gene back on, to stop the spread of the cancer.
Blueberries and strawberries, which are high in flavonoids, appear to reduce cognitive decline in older adults according to a new study published today in Annals of Neurology, a journal of the American Neurological Association and Child Neurology Society. The study results suggest that cognitive aging could be delayed by up to 2.5 years in elderly who consume greater amounts of the flavonoid-rich berries.
Flavonoids are compounds found in plants that generally have powerful antioxidant and anti-inflammatory properties. Experts believe that stress and inflammation contribute to cognitive impairment and that increasing consumption of flavonoids could mitigate the harmful effects. Previous studies of the positive effects of flavonoids, particularly anthocyanidins, are limited to animal models or very small trials in older persons, but have shown greater consumption of foods with these compounds improve cognitive function. Read the rest of this entry »
UC Santa Barbara researchers have discovered Salmonella bacteria that are up to 100 times more capable of causing disease. Their findings may help prevent food poisoning outbreaks that continue to plague public health and the food industry.
These “hypervirulent” bugs can override vaccines and pose a risk to food safety –– and mitigation efforts are currently under way.
Previous strategies to find the more dangerous bugs were unsuccessful since they behave like a “Trojan Horse”— exposing their weapons only when causing disease — but looking much like their less-virulent cousins in the environment.
Now that scientists know what to look for, they are developing methods to discriminate them from their less-virulent cousins. The researchers have been successful in forcing the bacteria to reveal their weapons in the laboratory –– the first step in combating them
Every year, millions of people are born with debilitating genetic disorders, a result of inheriting just one faulty gene from their parents. They may have been dealt a dud genetic hand, but they do not have to stick with it. With the power of modern genetics, scientists are developing ways of editing these genetic errors and reversing the course of many hard-to-treat diseases.
These gene therapies exploit the abilities of viruses – biological machines that are already superb at penetrating cells and importing genes. By removing their ability to reproduce, and loading them with the genes of our choice, we can transform viruses from causes of disease into vectors for cures.
After a few shaky starts, some of these approaches are beginning to hit their stride. Thirteen children with SCID, an immune disorder that leaves people fatally vulnerable to infections, now have working immune systems. Several British patients with haemophilia, which prevents their blood from clotting properly, can now produce a clotting protein called factor IX, which they once had to inject. A British man and three Americans with inherited forms of progressive blindness can see again.
Specialized compounds that naturally reduce inflammation in mice also help clear bacterial infections. A combination of these inflammation-resolving factors and antibiotics lowers the antibiotic dose needed to clear E. coli and Staphylococcus, according to a new paper in Nature.
The finding suggests it would be possible to stimulate a person’s own defenses to enhance the effects of antibiotics—a potentially valuable weapon in the fight against increasing rates of antibiotic resistance.
“This paper bridges two seemingly different and distant areas of research—antimicrobial resistance and the resolution of inflammation,” said Alberto Mantovani, an immunologist at the University of Milan in Italy who was not involved in the research. “It’s an unexpected perspective.”
S. aureus bacteria being attacked by human white blood cells.
Traumatic experiences in early life can leave emotional scars. But a new study suggests that violence in childhood may leave a genetic mark as well. Researchers have found that children who are physically abused and bullied tend to have shorter telomeres—structures at the tips of chromosomes whose shrinkage has been linked to aging and disease.
Telomeres prevent DNA strands from unravelling, much like the plastic aglets on a shoelace. When cells divide, these structures grow shorter, limiting the number of times a cell can reproduce. For this reason, telomeres may reflect biological age. Research has found associations between stress and accelerated telomere loss, and shortened telomeres correlate with several health problems, including diabetes, dementia, and fatigue.
Scientists have created artificial genetic material that can store information and evolve over generations in a similar way to DNA – a feat expected to drive research in medicine and biotechnology, and shed light on how molecules first replicated and assembled into life billions of years ago.
Ultimately, the creation of alternatives to DNA could enable scientists to make novel forms of life in the laboratory.
Researchers at the MRC Laboratory of Molecular Biology, in Cambridge, developed chemical procedures to turn DNA and RNA, the molecular blueprints for all known life, into six alternative genetic polymers called XNAs.
The process swaps the deoxyribose and ribose (the “d” and “r” in DNA and RNA) for other molecules. It was found the XNAs could form a double helix with DNA and were more stable than natural genetic material.
In the journal Science the researchers describe how they caused one of the XNAs to stick to a protein, an ability that might mean the polymers could be deployed as drugs working like antibodies.
DNA and RNA have been turned into alternative genetic polymers called XNAs by researchers in Cambridge. Photograph: Mopic/Alamy
Posted April 23, 2012on:
Scientists at the Allen Institute for Brain Science have identified similarities and differences among regions of the human brain, among the brains of human individuals, and between humans and mice by analyzing the expression of approximately 1,000 genes in the brain. The study, published online today in the journal Cell, sheds light on the human brain in general and also serves as an introduction to what the associated publicly available dataset can offer the scientific community.
This study reveals a high degree of similarity among human individuals. Only 5% of the nearly 1,000 genes surveyed in three particular regions show differences in expression between humans. In addition, comparison of this dataset to data in the Allen Mouse Brain Atlas indicates great consistency between humans and mice, as the human visual cortex appears to share 79% of its gene expression with that of the mouse.
The dataset, which is publicly available online via the Allen Brain Atlas data portal (www.brain-map.org) as part of the Allen Human Brain Atlas, holds promise for spurring further discoveries across the research community. Specifically, it contains detailed, cellular-level in situ hybridization gene expression data for about 1,000 genes, selected for their involvement in disease or neural function, in two distinct cortical areas of several disease-free adult human brains, both male and female.
Genes analyzed in this study fall into three categories: genes that serve as indicators of cell types found in the cortex, genes that are related to particular neural functions or diseases of the central nervous system, and genes that hold value for understanding the neural evolution of different species.
A new technique for analyzing brain images offers the possibility of using magnetic resonance imaging (MRI) to predict the rate of progression and physical path of many degenerative brain diseases, report scientists at the San Francisco VA Medical Center and the University of California, San Francisco.
The technique, developed by SFVAMC scientists in collaboration with a team led by Bruce Miller, MD, clinical director of the UCSF Memory and Aging Center, also supports mounting evidence that dementias spread through the brain along specific neuronal pathways in the same manner as prion diseases.
White matter connections in human brain (credit: David Shattuck, Arthur Toga, Paul Thompson/UCLA Lab of Neuro Imaging)
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Posted April 13, 2012on:
Two Massachusetts General Hospital (MGH)-based research teams, along with a group from the University of California at San Diego, have discovered that animals have a previously unknown system for detecting and responding to pathogens and toxins. In three papers published in the journals Cell and Cell Host & Microbe, the investigators describe finding evidence that disruptions to the core functions of animal cells trigger immune and detoxification responses, along with behavioral changes.
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Worrying may have evolved along with intelligence as a beneficial trait, according to a recent study by scientists at SUNY Downstate Medical Center and other institutions. Jeremy Coplan, MD, professor of psychiatry at SUNY Downstate, and colleagues found that high intelligence and worry both correlate with brain activity measured by the depletion of the nutrient choline in the subcortical white matter of the brain. According to the researchers, this suggests that intelligence may have co-evolved with worry in humans. Read the rest of this entry »
Posted April 12, 2012on:
Ripe for biomedical applications
Until recently, the production of pluripotent “multipurpose” stem cells from skin cells was considered to be the ultimate new development. In the meantime, it has become possible to directly convert cells of the body into one another – without the time-consuming detour via a pluripotent intermediate stage. However, this method has so far been rather inefficient. Scientists from the Bonn Institute of Reconstructive Neurobiology (director: Prof. Dr. Oliver Brüstle) have now developed the method to the point that it can be used for biomedical applications. The scientists are presenting their results in the journal “Nature Methods”.
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Working together can hasten brain evolution, according to a new computer simulation.
When programmed to navigate challenging cooperative tasks, the artificial neural networks set up by scientists to serve as mini-brains “learned” to work together, evolving the virtual equivalent of boosted brainpower over generations. The findings support a long-held theory that social interactions may have triggered brain evolution in human ancestors.
Image: Wikimedia Commons/Nicolas Rougier
Brain tumors and head trauma, including concussions, can elevate pressure inside the skull, potentially crushing brain tissue or cutting off the brain’s blood supply. Monitoring pressure in the brains of such patients could help doctors determine the best treatment, but the procedure is so invasive — it requires drilling a hole through the skull — that it is done only in the most severely injured patients.
That may change with the development of a new technique that is much less risky. The method, described in the April 11 issue of Science Translational Medicine, could allow doctors to measure brain pressure in patients who have suffered head injuries that are milder, but would benefit from close monitoring.
MIT researchers have developed a way to monitor pressure inside the brains of patients with injuries such as the bleeding seen in this CT scan.
Image: Lucien Monfils/wikipedia
Pregnant women might now have one more good reason to watch their diet and exercise: A new study links autism and developmental delays in young children to metabolic conditions, like obesity and diabetes, in their mothers.
The findings, published in Monday’s edition of the journal Pediatrics, found that women who had diabetes or hypertension or were obese were 1.61 times as likely as healthy women to have children with autism spectrum disorders. They also were 2.35 times as likely to have children with developmental delays.
Child development experts said the findings were interesting but that it would be premature to suggest that the results could help explain the dramatic rise in diagnosed cases of autism over the last decade.
Killing harmful bacteria in hospitals is difficult; out in the field, it can be an even bigger problem. Now, researchers may have a means for remote disinfection in a portable “flashlight” that shines a ray of cold plasma to kill bacteria in minutes.
Medical scientists have high hopes for plasmas. Produced in electrical discharges, these gases of free electrons and ions have already been shown to destroy pathogens, help heal wounds, and selectively kill cancer cells. No one is exactly sure how all of this works, but it seems that plasmas generate so-called reactive oxygen species in the air. These highly reactive molecules, which are present in our own immune system, oxidize cell membranes and damage DNA.
Plasma devices are already undergoing clinical testing to see whether they are safe to use. But these prototypes are limited: Either they need an external power source to generate the many kilovolts required for the electrical discharge, or they need an external gas supply and regulation to sustain the plasma. Such drawbacks make it difficult to use the devices in the field for emergency calls, natural disaster responses, or military operations.
The U.S. Food and Drug Administration (FDA) gave the O.K. last Friday to a new radioactive dye that helps doctors scan the brain for Alzheimer’s disease.
The dye, called Amyvid (florbetapir), made by Eli Lilly & Co., binds to the sticky amyloid proteins that build up in the brains of patients with Alzheimer’s. The dye can be detected by using positron emission tomography, or PET scans.
The test could allow doctors to diagnose Alzheimer’s much earlier and more accurately. In patients with symptoms of cognitive decline, the presence of amyloid would support an Alzheimer’s diagnosis. The dye cannot be used alone to diagnose Alzheimer’s, however, especially not in people without symptoms because people with normal brain function may accumulate amyloid plaques as they age, and because the plaques can be associated with neurological conditions other than Alzheimer’s.
Scientists at Novartis AG (NOVN) have discovered a compound that spurred cartilage growth from stem cells to fix damaged joints of mice, a finding that may point to a novel therapy for the arthritis that afflicts most elderly.
Researchers tested 22,000 drug-like molecules using a robotic screen, applying each one to bone marrow stem cells in tiny laboratory dishes. One compound, dubbed kartogenin, promoted the development of chondrocytes, cells that become cartilage, according to the report in the journal Science.
Researchers injected kartogenin into the damaged knee joints of mice, which prompted cartilage regeneration, improved symptoms and lowered levels of proteins and collagen fragments linked to damaged joints. The results suggest a unique, though early-stage, way to regulate cartilage and possibly repair some of the damage from osteoarthritis, the breakdown of cartilage that leads to joint failure, the researchers said.
The discovery of a major gear in the biological clock that tells the body when to sleep and metabolize food may lead to new drugs to treat sleep problems and metabolic disorders, including diabetes.
Scientists at the Salk Institute for Biological Studies, led by Ronald M. Evans, a professor in Salk’s Gene Expression Laboratory, showed that two cellular switches found on the nucleus of mouse cells, known as REV-ERBα and REV-ERBβ, are essential for maintaining normal sleeping and eating cycles and for metabolism of nutrients from food.
The findings describe a powerful link between circadian rhythms and metabolism and suggest a new avenue for treating disorders of both systems, including jet lag, sleep disorders, obesity and diabetes.
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Drugs made of protein have shown promise in treating cancer, but they are difficult to deliver because the body usually breaks down proteins before they reach their destination.
To get around that obstacle, a team of MIT researchers has developed a new type of nanoparticle that can synthesize proteins on demand. Once these “protein-factory” particles reach their targets, the researchers can turn on protein synthesis by shining ultraviolet light on them.
The particles could be used to deliver small proteins that kill cancer cells, and eventually larger proteins such as antibodies that trigger the immune system to destroy tumors, says Avi Schroeder, a postdoc in MIT’s David H. Koch Institute for Integrative Cancer Research and lead author of a paper appearing in the journal NanoLetters.
MIT researchers designed these particles that can produce proteins when ultraviolet light is shone on them. In this case, the protein is green fluorescent protein.
Image: Avi Schroeder
Men who eat flavonoid-rich foods such as berries, tea, apples and red wine significantly reduce their risk of developing Parkinson’s disease, according to new research by Harvard University and the University of East Anglia (UEA).
Published today in the journal Neurology ®, the findings add to the growing body of evidence that regular consumption of some flavonoids can have a marked effect on human health. Recent studies have shown that these compounds can offer protection against a wide range of diseases including heart disease, hypertension, some cancers and dementia.
This latest study is the first study in humans to show that flavonoids can protect neurons against diseases of the brain such as Parkinson’s. Read the rest of this entry »
You might recall a particular photograph that caused quite a stir back in 1999. It was the photograph of Samuel Armas, then just a 21-week-old fetus, reaching his tiny hand out from inside the uterus to clasp onto the doctor’s finger during a surgical procedure to correct the birth defect spina bifida. The fetal surgery at the time was still a bold undertaking, just two years after the first of its kind in 1997. Today, 13 years after Samuel’s “Hand of Hope,” the amazing procedure has been performed on over 400 fetuses around the world.
The immune system cancer known as lymphoma can often be cured, but some types remain stubbornly resistant to treatment. Now researchers have found a drug that appears to help vanquish these lymphomas by targeting their abnormal cell wiring. Tumors shrank in four of 10 advanced lymphoma patients treated with the drug, and one is still in remission more than a year later.
Diffuse large B-cell lymphoma, which involves immune cells called B cells, is one of the more common and dangerous lymphomas. Each year about 23,000 people in the United States are diagnosed with it, and some 10,000 die annually. Over the past decade, cancer biologist Louis Staudt’s team at the National Cancer Institute in Bethesda, Maryland, has analyzed patterns of gene activity within the malignant immune cells to break this cancer into subtypes, including one, activated B-cell-like (ABC) diffuse large B-cell lymphoma, that kills 60% of patients within 3 years. By dissecting the roles of different genes and proteins in the lymphoma cells, Staudt and colleagues have uncovered what appears to go wrong in this cancer: Genetic mutations cause B-cell receptors, proteins on the B cell’s surface that normally recognize infections, to send signals into the cell that block a self-destruction process that normally helps rid the body of abnormal cells. In lab studies, the lymphoma cells died when treated with an experimental drug called ibrutinib that overrides this anti-suicide signal. The drug blocks a protein called Bruton’s tyrosine kinase (BTK) that’s part of the B-cell-receptor signaling pathway.
Awakening from anesthesia is often associated with an initial phase of delirious struggle before the full restoration of awareness and orientation to one’s surroundings. Scientists now know why this may occur: primitive consciousness emerges first. Using brain imaging techniques in healthy volunteers, a team of scientists led by Adjunct Professor Harry Scheinin, M.D. from the University of Turku, Turku, Finland in collaboration with investigators from the University of California, Irvine, USA, have now imaged the process of returning consciousness after general anesthesia. The emergence of consciousness was found to be associated with activations of deep, primitive brain structures rather than the evolutionary younger neocortex.
These results may represent an important step forward in the scientific explanation of human consciousness. The study was part of the Research Programme on Neuroscience by the Academy of Finland.
Caption: This image shows one returning from oblivion — imaging the neural core of consciousness. Positron emission tomography (PET) findings show that the emergence of consciousness after anesthesia is associated with activation of deep, phylogenetically old brain structures rather than the neocortex. Left: Sagittal (top) and axial (bottom) sections show activation in the anterior cingulate cortex (i), thalamus (ii) and the brainstem (iii) locus coeruleus/parabrachial area overlaid on magnetic resonance image (MRI) slices. Right: Cortical renderings show no evident activations.
Targeted therapeutic nanoparticles that accumulate in tumors while bypassing healthy cells have shown promising results in an ongoing clinical trial, according to a new paper.
The nanoparticles feature a homing molecule that allows them to specifically attack cancer cells, and are the first such targeted particles to enter human clinical studies. Originally developed by researchers at MIT and Brigham and Women’s Hospital in Boston, the particles are designed to carry the chemotherapy drug docetaxel, used to treat lung, prostate and breast cancers, among others.
In the study, which appears April 4 in the journal Science Translational Medicine, the researchers demonstrate the particles’ ability to target a receptor found on cancer cells and accumulate at tumor sites. The particles were also shown to be safe and effective: Many of the patients’ tumors shrank as a result of the treatment, even when they received lower doses than those usually administered.
Does your mind wander? During a class or meeting, do you find yourself staring out the window and thinking about what you’ll do tomorrow or next week? As a child, were you constantly reminded by teachers to stop daydreaming?
Well, psychological research is beginning to reveal that daydreaming is a strong indicator of an active and well-equipped brain. Tell that to your third-grade teacher.
A new study, published in Psychological Science by researchers from the University of Wisconsin and the Max Planck Institute for Human Cognitive and Brain Science, suggests that a wandering mind correlates with higher degrees of what is referred to as working memory. Cognitive scientists define this type of memory as the brain’s ability to retain and recall information in the face of distractions.
A new drug that tackles advanced prostate cancer in three different ways has passed its first hurdle towards being approved.
Scientists reported promising early trial results using galeterone, which is designed to treat cancer that no longer responds to hormone therapy. However, researchers counselled caution as tests on the “triple whammy” drug have been carried out on only a small number of patients.
In their tests, scientists based at Harvard University reported that galeterone reduced levels of prostate specific antigen (PSA), a prostate cancer blood marker, by 30% or more in about half of patients. Eleven patients had PSA reductions of 50% or more, and in some there was significant shrinkage in tumour size.
A total of 49 patients took part in the phase one study, which primarily looked at safety and dosing levels. All had “refractory” or “castration resistant” cancer that had ceased to respond to hormone therapy. Currently there is little doctors can do to help prostate cancer patients who progress to this stage.
What is the relation between selective attention and consciousness? When you strain to listen to the distant baying of coyotes over the sound of a campsite conversation, you do so by attending to the sound and becoming conscious of their howls. When you attend to your sparring opponent out of the corner of your eye, you become hyperaware of his smallest gestures. Because of the seemingly intimate relation between attention and consciousness, most scholars conflate the two processes.
Image: John Rensten/Getty Images
The first atlas of the surface of the human brain based upon genetic information has been produced by a national team of scientists, led by researchers at the University of California, San Diego School of Medicine and the VA San Diego Healthcare System. The work is published in the March 30 issue of the journal Science.
The atlas reveals that the cerebral cortex – the sheet of neural tissue enveloping the brain – is roughly divided into genetic divisions that differ from other brain maps based on physiology or function. The genetic atlas provides scientists with a new tool for studying and explaining how the brain works, particularly the involvement of genes.
Standing up more often may reduce your chances of dying within three years, even if you are already physically active, a study of more than 200,000 people published in Archives of Internal Medicine today shows.
The study found that adults who sat 11 or more hours per day had a 40% increased risk of dying in the next three years compared with those who sat for fewer than four hours a day. This was after taking into account their physical activity, weight and health status. Read the rest of this entry »
Cheeseburgers pack on the pounds, but in mice a high-fat diet also packs on new nerve cells in the brain. More brain cells may seem like a good thing, but these newly sprouted cells appear to trigger weight gain in the animals, a new study finds.
The results offer insight into how the brain controls weight. If the same thing happens in humans, these nerve cells may be a target for anti-obesity treatments.
“This kind of work will definitely inform how we think about the underlying factors that relate to obesity,” says endocrinologist Jeffrey Flier of Harvard Medical School in Boston. There’s increasing interest, he says, in how long-term changes in brain circuitry — like new nerve cell production — affect eating and hunger. “That is going to be a very interesting frontier.”
A special brain cell called a tanycyte (green) was caught in the process of giving birth to a new neuron (marked with a white arrow) in a brain region called the median eminence. A high-fat diet spurs tanycytes to make new nerve cells in the brain, a new study finds. Credit: Daniel Lee/Blackshaw Lab
A hidden and never before recognized layer of information in the genetic code has been uncovered by a team of scientists at the University of California, San Francisco (UCSF) thanks to a technique developed at UCSF called ribosome profiling, which enables the measurement of gene activity inside living cells — including the speed with which proteins are made.
By measuring the rate of protein production in bacteria, the team discovered that slight genetic alterations could have a dramatic effect. This was true even for seemingly insignificant genetic changes known as “silent mutations,” which swap out a single DNA letter without changing the ultimate gene product. To their surprise, the scientists found these changes can slow the protein production process to one-tenth of its normal speed or less.
As described today in the journal Nature, the speed change is caused by information contained in what are known as redundant codons — small pieces of DNA that form part of the genetic code. They were called “redundant” because they were previously thought to contain duplicative rather than unique instructions.