Archive for February 2010
Life’s smallest motor, a protein that shuttles cargo within cells and helps cells divide, does so by rocking up and down like a seesaw, according to research conducted by scientists at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and Brandeis University.
The researchers created high-resolution snapshots of a protein motor, called kinesin, as it walked along a microtubule, which are tube-shaped structures that form a cell’s “skeleton.” The result is the closest look yet at the structural changes kinesin proteins undergo as they ferry molecules within cells. Read the rest of this entry »
Researchers investigating UK samples have found no association between the controversial xenotropic murine leukaemia virus-related virus (XMRV) and chronic fatigue syndrome (CFS). Their study, published in BioMed Central’s open access journal Retrovirology, calls into question a potential link described late last year by an American research team. Read the rest of this entry »
A rare study that tracked thousands of children through adulthood found the heaviest youngsters were more than twice as likely as the thinnest to die prematurely, before age 55, of illness or a self-inflicted injury.
Youngsters with a condition called pre-diabetes were at almost double the risk of dying before 55, and those with high blood pressure were at some increased risk. But obesity was the factor most closely associated with an early death, researchers said.
Posted February 14, 2010on:
Eyeballs just don’t become toenails — even though the same genome sits in the nucleus of every cell. The difference is in the parts of the genome that are expressed — a cell’s identity is determined by the specific genes that are active within that cell. The differentiation of a cell, and a cell’s commitment to become a particular type, have been long considered irreversible processes.
Stem cells (embryonic ES or induced iPS cells) have not yet committed to become any particular cell type, and they exist in an entirely undifferentiated stage. Only stem cells can become any type of cell in a particular organism –- the property of pluripotency. Pluripotent stem cells become the slightly more differentiated, slightly more distinctive, multipotent adult stem or progenitor cells –- neural stem cells can become any type of cell in the nervous system; hematopoietic stem cells can become any type of cell in the blood.
Posted February 14, 2010on:
As Olympians go for the gold in Vancouver, even the steeliest are likely to experience that familiar feeling of “butterflies” in the stomach. Underlying this sensation is an often-overlooked network of neurons lining our guts that is so extensive some scientists have nicknamed it our “second brain”.
A deeper understanding of this mass of neural tissue, filled with important neurotransmitters, is revealing that it does much more than merely handle digestion or inflict the occasional nervous pang. The little brain in our innards, in connection with the big one in our skulls, partly determines our mental state and plays key roles in certain diseases throughout the body.
Removing part of the brain can induce inner peace, according to researchers from Italy. Their study provides the strongest evidence to date that spiritual thinking arises in, or is limited by, specific brain areas.
To investigate the neural basis of spirituality, Cosimo Urgesi, a cognitive neuroscientist at the University of Udine, and his colleagues turned to people with brain tumours to assess the feeling before and after surgery. Three to seven days after the removal of tumours from the posterior part of the brain, in the parietal cortex, patients reported feeling a greater sense of self-transcendence. This was not the case for patients with tumours removed from the frontal regions of the brain.
Lights and wings have been associated with spirituality in different cultures.Urgesi, C. et al
Stuttering may be the result of a glitch in the day-to-day process by which cellular components in key regions of the brain are broken down and recycled, says a study in the Feb. 10 Online First issue of the New England Journal of Medicine. The study, led by researchers at the National Institute on Deafness and Other Communication Disorders (NIDCD), part of the National Institutes of Health, has identified three genes as a source of stuttering in volunteers in Pakistan, the United States, and England. Mutations in two of the genes have already been implicated in other rare metabolic disorders also involved in cell recycling, while mutations in a third, closely related, gene have now been shown to be associated for the first time with a disorder in humans. Read the rest of this entry »
Why do people with fragile X syndrome, a genetic defect that is the best-known cause of autism and inherited mental retardation, recoil from hugs and physical touch – even from their parents?
New research has found in fragile X syndrome there is delayed development of the sensory cortex, the part of the brain that responds to touch, according to a study from Northwestern University Feinberg School of Medicine. This delay may trigger a domino effect and cause further problems with the correct wiring of the brain. Understanding how and when the function of the brain is affected in fragile X offers a target for a therapy to fix the incorrect development. Read the rest of this entry »
Humanity’s physical design flaws have long been apparent – we have a blind spot in our vision, for instance, and insufficient room for wisdom teeth – but do the imperfections extend to the genetic level?
In his new book, Inside the Human Genome, John Avise examines why – from the perspectives of biochemistry and molecular genetics – flaws exist in the biological world. He explores the many deficiencies of human DNA while recapping recent findings about the human genome.
Distinguished Professor of ecology & evolutionary biology at UC Irvine, Avise also makes the case that overwhelming scientific evidence of genomic defects provides a compelling counterargument to intelligent design. Read the rest of this entry »
Posted February 13, 2010on:
UCLA chemists report creating a synthetic “gene” that could capture heat-trapping carbon dioxide emissions, which contribute to global warming, rising sea levels and the increased acidity of oceans.
“We created three-dimensional, synthetic DNA-like crystals,” said UCLA chemistry and biochemistry professor Omar M. Yaghi, who is a member of the California NanoSystems Institute (CNSI) at UCLA and the UCLA–Department of Energy Institute of Genomics and Proteomics. “We have taken organic and inorganic units and combined them into a synthetic crystal which codes information in a DNA-like manner. It is by no means as sophisticated as DNA, but it is certainly new in chemistry and materials science.”
The discovery could lead to cleaner energy, including technology that factories and cars can use to capture carbon dioxide before it reaches the atmosphere.
Posted February 13, 2010on:
Researchers at McMaster University have developed a cocktail of ingredients that forestalls major aspects of the aging process.
“As we all eventually learn, ageing diminishes our mind, fades our perception of the world and compromises our physical capacity,” says David Rollo, associate professor of biology at McMaster. “Declining physical activity—think of grandparents versus toddlers—is one of the most reliable expressions of ageing and is also a good indicator of obesity and general mortality risk.”
The study found that a complex dietary supplement powerfully offsets this key symptom of ageing in old mice by increasing the activity of the cellular furnaces that supply energy—or mitochondria—and by reducing emissions from these furnaces—or free radicals—that are thought to be the basic cause of ageing itself. Read the rest of this entry »
Giving chocolates to your Valentine on February 14th may help lower their risk of stroke based on a preliminary study from researchers at St. Michael’s Hospital. The study, which is being presented at the American Academy of Neurology in April, also found that eating chocolate may lower the risk of death after suffering a stroke.
Yale University scientists have streamlined the process for synthesizing a family of compounds with the potential to kill cancer and other diseased cells, and have found that they represent a unique category of anti-cancer agents. Their discovery appears in this week’s online edition of theJournal of the American Chemical Society.
The team studied a family of compounds known as the kinamycins, which are naturally produced by bacteria during metabolism and are known for their potent toxicity. For years scientists have guessed that a core structure common to the different compounds within the group was responsible for this toxicity. Until now, chemists could not study the core structure because there was no simple way to create it in the laboratory.
Now the Yale team has developed a new method to recreate this structure that allows them to synthesize the kinamycins with much greater efficiency than previously possible. While scientists have produced kinamycins in the laboratory in the past, the Yale team was able to halve the number of steps required to go from simple, easily obtainable precursors to the complete molecule—from 24 down to 12. Read the rest of this entry »
Avoiding potentially dangerous silent strokes may be another health benefit of following a Mediterranean diet.
A new study shows people who most closely followed a Mediterranean-style diet were 36% less likely to have areas of brain damage linked to silent strokes than those who least closely followed the diet. These areas of brain damage, called brain infarcts, are a result of silent strokes that can occur without symptoms or a person knowing it.
A new screening tool developed by scientists in Denmark may help detect the earliest stages of cancer by taking advantage of the body’s own defenses. The researchers constructed a microarray system that analyzes patients’ blood for a specific class of immune agents called autoantibodies. These are agents that attack the body’s own tissue, targeting what they perceive as “foreign” cells, such as specific molecules on the surface of tumors.
Immune tracer: This image shows the overexpression of cancer-associated glycan structures (green) on proteins in cancer cells. The cells’ nuclei are stained in blue. Credit: Kirstine Lavrsen
The researchers found that, within a limited number of blood samples, the screening test could detect cancer-associated autoantibodies in patients recently diagnosed with prostate, breast, and ovarian cancer. Healthy individuals showed no signs of the immune agents in their blood. Their findings, published in the journal Cancer Research, suggest that autoantibodies may be effective biomarkers for early cancer development.
Even though nearly 2,000 genetic tests are available today, most Americans have never taken one. (Save, perhaps, for newborn screening.) That may soon change, as the nation’s largest businesses responsible for managing prescription benefits, Medco and CVS Caremark, delve into the DNA testing business. Taken together, the two companies cover more than 100 million Americans.
Swine Flu. Spanish Flu. SARS. Almost every year, it seems, there is a new virus to watch out for. Roughly thirty thousand Americans die annually from a new flu strain — meaning roughly one flu fatality for every two victims of car accidents — and there is always the possibility that we will do battle with a much deadlier strain of flu virus, such as the one cousin to the current swine flu that killed 50 million people in 1918.
Researchers have identified a compound that mimics one of the brains own growth factors and can protect brain cells against damage in several animal models of neurological disease.
7,8-dihydroxyflavone is a member of the flavonoid family of chemicals, which are abundant in fruits and vegetables. The compound’s selective effects suggest that it could be the founder of a new class of brain-protecting drugs. Read the rest of this entry »
Peptides that target blood vessels in fat and cause them to go into programmed cell death (termed apoptosis) could become a model for future weight-loss therapies, say University of Cincinnati (UC) researchers.
A research team led by Randy Seeley, PhD, of UC’s Metabolic Diseases Institute, has found that obese animal models treated with proapoptotic peptide experienced decreased food intake and significant fat loss. Read the rest of this entry »
Hepatitis C, a virus that can cause liver failure or cancer, infects about 200 million people worldwide. Existing drugs are not always effective, so many patients end up on long liver-transplant waiting lists.
One reason that no better treatment options exist is the lack of a suitable liver tissue model to test new drugs in the laboratory. But now, researchers from MIT and Rockefeller University have successfully grown hepatitis C viruses in otherwise healthy liver cells.
In the new tissue model, liver cells are precisely arranged on a specially patterned plate and surrounded by supportive cells, allowing them to live and function for four to six weeks. The cells can be infected with hepatitis C for two to three weeks, giving researchers the chance to study the cells’ responses to different drugs.
Think twice the next time you wipe a few flecks of dandruff from your shoulder. You might be shedding cells that may someday restore human vision.
Thomas Reh and colleagues at the University of Washington, in Seattle, have generated light-sensing retinal cells, called photoreceptors, from adult human skin cells. They then transplanted the cells into a mouse retina, showing that the photoreceptors integrated normally into the surrounding tissue. This technological feat raises hopes for the development of treatments for retinal diseases, such as retinitis pigmentosa and macular degeneration, which cause visual impairment or blindness in millions of people in the U.S. Read the rest of this entry »
The Medpedia Project today announced Medpedia Clinical Trials, a platform for patients and physicians to receive information about the thousands of clinical trials that are in process or about to begin. Other online sources already allow for searching clinical trials, but the Medpedia platform allows clinical trial information to be “pushed” or fed automatically to appropriate contexts. For instance, trial information can show up alongside a Medpedia article covering the same condition, it can appear in a personalized feed of someone interested in that condition, or in a patient community related to that condition. This free resource is available now on Medpedia at http://www.medpedia.com/clinical-trials
via Press – Medpedia.
- A coffee break after an important meeting or class may be just the thing your brain needs to digest new information and improve memory.
A new study suggests that resting while awake aids in memory consolidation and improves memory recall, much like getting a good night’s sleep has been shown to do.
“Taking a coffee break after class can actually help you retain that information you just learned,” researcher Lila Davachi, PhD, assistant professor of psychology at the Center for Neural Science at New York University, says in a news release. “Your brain wants you to tune out other tasks so you can tune in to what you just learned.”
Researchers found that activity between the hippocampus and neocortex, two key brain areas involved in memory and processing, increased during periods of wakeful rest after a learning task. This increase in activity was also associated with improved memory.
When it comes to aggressive cancers, in the brain or lung for example, oncologists know that the sooner they can determine whether a treatment is unsuccessful, the sooner they can reevaluate and, if necessary, prescribe a new course of action. But typically, it takes two months or more to do the before-and-after comparisons that help determine whether a tumor is shrinking. Now an Israeli company called Aposense says it may have found a way to drastically speed up the process: an imaging marker that, when used with PET scans, indicates the presence of dying cells.
Death of a tumor: This PET scan, taken just days after radiation therapy, shows a hot spot of cell-death activity in a brain tumor–a good indication that the therapy is working.
Credit: Aaron Allen, Davidoff Comprehensive Cancer Center, Rabin Medical Center
Apoptosis, the process by which cells commit suicide, is a vital mechanism in the body that weeds out damaged, infected, or otherwise unhealthy cells. No matter what the disease or the tissue, cells undergoing apoptosis have very distinct characteristics–the electrical profile of their membrane changes, the cells become more acidic, and lipids in the membrane lose their rigid order and become jumbled. Aposense believes it has found a way to target a trace marker to this combination of traits, which would let doctors image cell death and thereby determine whether radiation and chemotherapy are working within just a few days after treatment begins.
Subatomic particles do it. Now the observation that groups of brain cells seem to have their own version of quantum entanglement, or “spooky action at a distance”, could help explain how our minds combine experiences from many different senses into one memory.
Previous experiments have shown that the electrical activity of neurons in separate parts of the brain can oscillate simultaneously at the same frequency – a process known as phase locking. The frequency seems to be a signature that marks out neurons working on the same task, allowing them to identify each other.
Call it pork in a petri dish — a technique to turn pig stem cells into strips of meat that scientists say could one day offer a green alternative to raising livestock, help alleviate world hunger, and save some pigs their bacon.
Dutch scientists have been growing pork in the laboratory since 2006, and while they admit they haven’t gotten the texture quite right or even tasted the engineered meat, they say the technology promises to have widespread implications for our food supply.
“If we took the stem cells from one pig and multiplied it by a factor of a million, we would need one million fewer pigs to get the same amount of meat,” said Mark Post, a biologist at Maastricht University involved in the In-vitro Meat Consortium, a network of publicly funded Dutch research institutions that is carrying out the experiments
What if a jury could decide a man’s guilt through mind reading? What if reading a defendant’s memory could betray their guilt? And what constitutes ‘intent’ to commit murder? These are just some of the issues debated and reviewed in the inaugural issue of WIREs Cognitive Science, the latest interdisciplinary project from Wiley-Blackwell, which for registered institutions will be free for the first two years.
In the article “Neurolaw,” in the inaugural issue of WIREs Cognitive Science, co-authors Walter Sinnott-Armstrong and Annabelle Belcher assess the potential for the latest cognitive science research to revolutionize the legal system.
Read the rest of this entry »
Researchers in Manchester have successfully carried out the first rewire of genetic switches, creating what could be a vital tool for the development of new drugs and even future gene therapies.
A team of scientists from the School of Chemistry and the Manchester Interdisciplinary Biocentre (MIB) at The University of Manchester have found a way of hijacking so-called ‘riboswitches’ and directing gene activity.
Genetic adaption to meat-rich diets may also lead to high rates of Alzheimer’s and heart disease
The same evolutionary genetic advantages that have helped increase human lifespans also make us uniquely susceptible to diseases of aging such as cancer, heart disease and dementia, reveals a study to be published in a special PNAS collection on “Evolution in Health and Medicine” on Tuesday, Jan. 26. Read the rest of this entry »
Posted February 1, 2010on:
Antioxidants increasingly have been praised for their benefits against disease and aging, but recent studies at Kansas State University show that they also can cause harm.
Researchers in K-State’s Cardiorespiratory Exercise Laboratory have been studying how to improve oxygen delivery to the skeletal muscle during physical activity by using antioxidants, which are nutrients in foods that can prevent or slow the oxidative damage to the body. Their findings show that sometimes antioxidants can impair muscle function. Read the rest of this entry »
Researchers trying to restore vision damaged by disease have found promise in a tiny implant that sows seeds of new cells in the eye.
The diseases macular degeneration and retinitis pigmentosa lay waste to photoreceptors, the cells in the retina that turn light into electrical signals carried to the brain. The damage leaves millions of people worldwide with debilitating sight loss.
The nerves behind the light-switching cells, however, remain intact, meaning that with new photoreceptors, a patient could see again. Read the rest of this entry »
Scientists have created a new computational model that can be used to predict gene function of uncharacterized plant genes with unprecedented speed and accuracy. The network, dubbed AraNet, has over 19,600 genes associated to each other by over 1 million links and can increase the discovery rate of new genes affiliated with a given trait tenfold. It is a huge boost to fundamental plant biology and agricultural research.
Despite immense progress in functional characterization of plant genomes, over 30% of the 30,000 Arabidopsis genes have not been functionally characterized yet. Another third has little evidence regarding their role in the plant.