Obesity may have harmful effects on the brain, and exercise may counteract many of those negative effects, according to sophisticated new neurological experiments with mice, even when the animals do not lose much weight. While it’s impossible to know if human brains respond in precisely the same way to fat and physical activity, the findings offer one more reason to get out and exercise.
It’s been known for some time that obesity can alter cognition in animals. Past experiments with lab rodents, for instance, have shown that obese animals display poor memory and learning skills compared to their normal-weight peers. They don’t recognize familiar objects or recall the location of the exit in mazes that they’ve negotiated multiple times.
But scientists hadn’t understood how excess weight affects the brain. Fat cells, they knew, manufacture and release substances into the bloodstream that flow to other parts of the body, including the heart and muscles. There, these substances jump-start biochemical processes that produce severe inflammation and other conditions that can lead to poor health.
Many thought the brain, though, should be insulated from those harmful effects. It contains no fat cells and sits behind the protective blood-brain barrier that usually blocks the entry of undesirable molecules.
However, recent disquieting studies in animals indicate that obesity weakens that barrier, leaving it leaky and permeable. In obese animals, substances released by fat cells can ooze past the barrier and into the brain.
Tailor-made medical devices could give a more detailed picture of cardiac health and may be better at predicting and preventing problems.
It’s a poetic fact of biology that everyone’s heart is a slightly different size and shape. And yet today’s cardiac implants—medical devices like pacemakers and defibrillators—are basically one size fits all. Among other things, this means these devices, though lifesaving for many patients, are limited in the information they can gather.
Researchers recently demonstrated a new kind of personalized heart sensor as part of an effort to change that. The researchers used images of animals’ hearts to create models of the organ using a 3-D printer. Then they built stretchy electronics on top of those models. The stretchy material can be peeled off the printed model and wrapped around the real heart for a perfect fit.
The research team has also integrated an unprecedented number of components into these devices, demonstrating stretchy arrays of sensors, oxygenation detectors, strain gauges, electrodes, and thermometers made to wrap perfectly around a particular heart. For patients, this could mean more thorough, better-tailored monitoring and treatment.
One device in need of improvement is the implanted defibrillator, which is attached to a misfiring heart and uses readings from one or two electrodes to determine whether to restore a normal heartbeat by applying an electric shock. With information from just one or two points, the electronics in these systems can make the wrong decision, giving the patient a painful unnecessary shock, says Igor Efimov, a cardiac physiologist and bioengineer at Washington University in St. Louis.
An ancient virus has come back to life after lying dormant for at least 30,000 years, scientists say.
It was found frozen in a deep layer of the Siberian permafrost, but after it thawed it became infectious once again.
The French scientists say the contagion poses no danger to humans or animals, but other viruses could be unleashed as the ground becomes exposed.
The study is published in the Proceedings of the National Academy of Sciences (PNAS).
Professor Jean-Michel Claverie, from the National Centre of Scientific Research (CNRS) at the University of Aix-Marseille in France, said: "This is the first time we've seen a virus that's still infectious after this length of time."
Watson's controversial hypothesis about cause of diabetes, dementia, heart disease and cancer published in medical journal
Not satisfied with his work that unravelled the double helix structure of DNA and landed him a share of a Nobel prize half a century ago, James Watson has come up with a radical theory for diabetes, dementia, heart disease and cancer.
The 85-year-old scientist has turned to the pages of the Lancet medical journal to set forth his grand idea, which some academics say may not have seen the light of day had it come from anyone else.
Watson, who stepped down as director of the Cold Spring Harbour Laboratory in New York in 2007 after the Times quoted his views on Africa and intelligence, has arranged a conference at the lab this year to explore his latest hypothesis.
Writing in the Lancet, Watson claims that late onset, or type 2 diabetes, is traditionally thought to be caused by oxidation in the body that causes inflammation and kills off pancreatic cells. But he thinks the root of that inflammation is quite different: "The fundamental cause, I suggest, is a lack of biological oxidants, not an excess," he writes.
Watson, a keen singles tennis player, says he developed his theory after pondering why exercise seemed to benefit people with high blood sugar, an early indicator of future diabetes. Exercise produced "reactive oxygen species" that were widely thought to be harmful.
Other research fed into his thinking, chiefly a study by Matthias Blüher at the University of Leipzig. He showed that reactive oxygen species released in exercise combatted the insulin resistance seen in diabetes, but that the benefits vanished if you gave people antioxidants before the exercised.
Watson believes that rather than being wholly bad, oxidising molecules, such as hydrogen peroxide, are crucial for the body's health. In particular, he points out that hydrogen peroxide goes to work in a cellular organ called the endoplasmic reticulum, where it ensures proteins are stable. If levels of oxidants are too low, he suggests, the proteins become misshapen and cause the inflammation that damages the pancreas. And a raft of other diseases.
Some people recall a dream every morning, whereas others rarely recall one. In a new study, research shows that the temporo-parietal junction, an information-processing hub in the brain, is more active in high dream recallers. Increased activity in this brain region might facilitate attention orienting toward external stimuli and promote intrasleep wakefulness, thereby facilitating the encoding of dreams in memory.
As we discover more about love's neural basis, we are getting closer to a pill to diminish heartbreak
ROSES are red, violets are blue, when you reject me, what can I do? As we discover more about love's neural basis, we are getting closer to a way of curing its ills.
While many might be wary of a chemical cure for heartbreak, there is an argument that such anti-love solutions could help people struggling with suicidal or delusional thoughts because of unrequited love, or those in the clutches of unrelenting grief. The morals of the use and misuse of such drugs are complex (see "Cure for love: Should we take anti-love drugs?"), but ethics aside, what could a cure for love look like?
First things first: what is love? For Shakespeare, it "is an ever-fixed mark, that looks on tempests and is never shaken". For neuroscientists, it's less poetic: a neurobiological phenomenon that falls into three subtypes: lust, attraction and attachment – all of which increase our reproductive and parental success.
Each aspect is grounded in a suite of overlapping chemical systems in the brain. There are ways to diminish each of them, says Helen Fisher at Rutgers University in New Jersey, but they aren't always palatable.
Take lust. Ever found yourself obsessing over the tiniest details of a person? Their hair, say, or the number of kisses in a text? This tunnel vision resembles some of the symptoms of obsessive compulsive disorder, so Donatella Marazziti at the University of Pisa in Italy, compared the brains of 20 people in the first throes of love with those of 20 people with OCD.
Both groups had unusually low levels of a protein that transports serotonin – a hormone involved in regulating mood – around the brain. Retesting the lovers a year later revealed that their serotonin levels had increased, and that they no longer reported an obsessive focus on their partners.
Andrew Anthony sent his stool off to have its bacteria sequenced. In the future, such techniques could help assess our susceptibility to conditions from diabetes, Parkinson's and Alzheimer's to autism, depression and cancer
We are all familiar with "gut feelings", "gut reactions" and "gut instincts", but how much do we really know or care about our guts? As we become increasingly more aware of what we put in our stomachs, it's striking how ignorant we remain of what takes place in our intestines. And it turns out there is an awful lot going on down there.
Microbiologists have made some startling advances in revealing our innermost secrets. It turns out that there is a complex ecosystem deep within us that is home to a fantastic diversity of life – of which very little belongs to our species.
For most of us, suspicious of foreign bodies, it's a struggle to comprehend that at our very core we are less than – or rather much more than – human. But, the fact is, there are about 100 trillion organisms living in the gut. If you put them all together they would be about the size of a football. In terms of cells, the microbial kind outnumber their human counterparts by about three to one. And in terms of genes, the microbial advantage is more like 300 to one.
That means there is a tremendous amount of us that is not, so to speak, us. This raises a whole range of interesting philosophical and anatomical questions, of which the most urgent might be: should we be worried?
A scientific team has made a surprising discovery about the brain's hunger-inducing neurons, a finding with important implications for the treatment of obesity.
While the function of eating is to nourish the body, this is not what actually compels us to seek out food. Instead, it is hunger, with its stomach-growling sensations and gnawing pangs that propels us to the refrigerator – or the deli or the vending machine. Although hunger is essential for survival, abnormal hunger can lead to obesity and eating disorders, widespread problems now reaching near-epidemic proportions around the world.
Your memory is a wily time traveler, plucking fragments of the present and inserting them into the past, reports a new Northwestern Medicine® study. In terms of accuracy, it's no video camera.
Rather, the memory rewrites the past with current information, updating your recollections with new experiences.
Love at first sight, for example, is more likely a trick of your memory than a Hollywood-worthy moment.
"When you think back to when you met your current partner, you may recall this feeling of love and euphoria," said lead author Donna Jo Bridge, a postdoctoral fellow in medical social sciences at Northwestern University Feinberg School of Medicine. "But you may be projecting your current feelings back to the original encounter with this person."
The study will be published Feb. 5 in the Journal of Neuroscience.
Macaques in China are the first primates born with genomes engineered by precision gene-targeting methods.
Researchers at Nanjing Medical University and Yunnan Key Laboratory of Primate Biomedical Research in Kunming, China, have created genetically modified monkeys using a new method of DNA engineering known as Crispr. The infant macaques show that targeted genome editing is feasible in primates—a potential boon for scientists studying complex diseases, including neurological ones, and an advance that suggests that the method could one day work in humans. The work was reported in the journal Cell on Thursday.
Scientists have previously used the new genome-editing technique to delete, insert, and modify DNA in human cells and other animal cells grown in petri dishes. The method has also been used to create gene modifications in whole animals such as mice, rats, and zebrafish. The new study shows for the first time that Crispr can create viable primates with genomes modified at specific targeted genes.
The Chinese researchers injected single-cell macaque embryos with RNAs to guide the genome-editing process. The team modified three genes in the monkeys: one that regulates metabolism, another that regulates immune cell development and a third that regulates stem cells and sex determination, says study coauthor Wezhi Ji, a researcher at the Yunnan Key Laboratory of Primate Biomedical Research. The researchers found that the genome-editing tools created multiple changes in their target genes at different stages of embryonic development. The infant monkeys are too young for the team to yet determine if the genetic changes have an effect on physiology or behavior, says Ji. But, he adds, “data from this species should be very useful for curing human disease and improving human health.”
Researchers have previously created a handful of transgenic monkeys, such as a rhesus macaque that produces the disease-causing version of the Huntington’s gene. Researchers at Emory University in Atlanta created this avatar of human disease by injecting a virus into macaque eggs. The virus delivered a disease-version of the human Huntington’s gene into a random location in the monkey’s genome.
Once mocked as having the erotic appeal of a jellyfish, the female condom is being reinvented as the next big thing in protective sex. In the first article from new digital publication Mosaic, Emily Anthes takes an in-depth investigation to see what chance it has of catching on this time around.
In 1987, an American pharmaceutical executive called Mary Ann Leeper flew to Copenhagen to get a first-hand look at what she thought might be the world’s next great health innovation. She didn’t expect to find it tucked away inside an old cigar box.
When she arrived at the old farmhouse owned by Danish doctor and inventor Lasse Hessel, he opened the door with a cigar in his mouth. Then he fetched the box. “Inside were all these bits and pieces – metal, plastic, all different kinds of stuff,” Leeper recalls. “I took a deep breath and thought, ‘Holy mother – what have I gotten myself into?’” Somehow, these bits and pieces fit together to form a contraption that women could wear during sex to prevent pregnancy and sexually transmitted infections – the world’s first female condom.
The presentation may have been unconventional, but Leeper and her colleagues at Wisconsin Pharmacal had high hopes for Hesse’s invention. “The Aids crisis in the United States was just fully being recognised, and it was clear to us that for women to have a product that they could use to help protect themselves would be a good thing,” Leeper says.
Indeed, when Wisconsin Pharmacal finally introduced the female condom to the US in 1993, public health experts hailed it as a game-changer. The condom, a polyurethane pouch inserted into the vagina before sex, would protect women from sexually transmitted infections even if their male partners refused to wear condoms.
Technically, the female condom works. When used correctly, it reduces a woman’s risk of contracting HIV by around 94–97% each time she had sex, according to estimates. Studies show that making female condoms available alongside the male version increases the percentage of sexual acts that are protected, and decreases the prevalence of sexually transmitted infections.
Controversial technique, currently banned, would prevent women from passing mitochondrial diseases to their children
The Department of Health has launched a three-month consultation on the draft regulations for a radical procedure that aims to prevent mothers from passing on serious genetic diseases to their children, a controversial technique because it leads to babies with DNA from three people.
Mitochondrial transfer has never been tried in humans and is prohibited in Britain under laws that ban the placing of an egg or embyro into a woman if the DNA has been altered. But scientists working on the technique said it offered hope of preventing life-threatening diseases for which there were no cures.
The government announced last June that it intends to allow the procedure, but the regulations must be finalised, debated and approved by parliament before the Human Fertilisation and Embryology Authority (HFEA) can allow clinics to offer the treatment.
About one in 200 children born in the UK have some form of mitochondrial disorder. The most serious affect the heart, brain, muscles and liver. Under the procedure, the nucleus is removed from an affected woman's egg or from a cell in an embryo and transferred to a donor egg or embryo that has healthy mitochondria.
As a result, a baby will have DNA from the biological parents and a female donor who provides healthy mitochondria, the tiny biological batteries that power most cells in the body. The fraction of a cell's DNA that is in mitochondria is minuscule and affects only how cells are powered. It does not influence the child's physical appearance or personality.
Phlebotomy. Even the word sounds archaic—and that’s nothing compared to the slow, expensive, and inefficient reality of drawing blood and having it tested. As a college sophomore, Elizabeth Holmes envisioned a way to reinvent old-fashioned phlebotomy and, in the process, usher in an era of comprehensive superfast diagnosis and preventive medicine. That was a decade ago. Holmes, now 30, dropped out of Stanford and founded a company called Theranos with her tuition money. Last fall it finally introduced its radical blood-testing service in a Walgreens pharmacy near the company headquarters in Palo Alto, California. (The plan is to roll out testing centers nationwide.) Instead of vials of blood—one for every test needed—Theranos requires only a pinprick and a drop of blood. With that they can perform hundreds of tests, from standard cholesterol checks to sophisticated genetic analyses. The results are faster, more accurate, and far cheaper than conventional methods. The implications are mind-blowing. With inexpensive and easy access to the information running through their veins, people will have an unprecedented window on their own health. And a new generation of diagnostic tests could allow them to head off serious afflictions from cancer to diabetes to heart disease.
The XStat syringe, filled with scientifically advanced sponges, can plug a life-threatening bullet wound in a matter of seconds.
Caught in a fire fight, a soldier might hope for air support rained down from a Predator Drone, a kitted out AR-15 assault rifle, and soon, a tube full of high-tech cotton balls. The last item on the list might seem out of place, but the XStat syringe, filled with scientifically advanced sponges, can plug a life-threatening bullet wound in a matter of seconds.
Tourniquets are useful tools for injuries to extremities, but gushing wounds in the pelvis or shoulder require a different approach. The current standard of care is stuffing gauze into the wound. Not only is gauze not FDA cleared for this application, it’s often painful, imprecise, and ineffective, requiring field medics to repeat the agonizing process.
A company called RevMedx decided to approach the problem in a different manner after being inspired by expanding foams used to patch tires and walls. Realizing that foams wouldn’t be effective, they cut up ordinary sink sponges and stuffed them into wounded pigs. Their makeshift “medical device” worked, and a $5 million development contract from the U.S. Army followed shortly thereafter.
A mother's milk may contain different levels of nutrients depending on the sex of her baby to meet different growth needs
Baby formula should be tailored for boys and girls to reflect the differences in milk that mothers produce depending on their baby's sex, researchers say.
Tests on mothers' milk in both monkeys and humans have showed that levels of fat, protein, vitamins, sugars, minerals and hormones vary enormously, but there is evidence that milk made for female and male babies is consistently different.
The make-up of the milk has a direct impact on the child's growth, but also on his or her behaviour and temperament, which may last for the rest of their life. Scientists suspect that breast milk may be tailored by nature to meet the different growth needs of the sexes.
The findings have led some researchers to suggest that baby formula should come in boy and girl formulations to match the differences seen in breast milk.
"We have good reason to be sceptical of a one-size-fits-all formula," said Prof Katie Hinde, an evolutionary biologist at Harvard University.
We often worry about lying awake in the middle of the night - but it could be good for you. A growing body of evidence from both science and history suggests that the eight-hour sleep may be unnatural.
In the early 1990s, psychiatrist Thomas Wehr conducted an experiment in which a group of people were plunged into darkness for 14 hours every day for a month.
It took some time for their sleep to regulate but by the fourth week the subjects had settled into a very distinct sleeping pattern. They slept first for four hours, then woke for one or two hours before falling into a second four-hour sleep.
Though sleep scientists were impressed by the study, among the general public the idea that we must sleep for eight consecutive hours persists.
Worm study suggests that activity in mitochondria determines ageing.
Scientists have a crystal ball on their hands: bursts of activity in the energy-producing mitochondria in a worm’s cells accurately predict how long it will live.
The findings, published today in Nature1, suggest that an organism’s lifespan is, for the most part, predictable in early adulthood. Unlike other biomarkers for ageing, which work under limited conditions, these mitochondrial bursts are a stable predictor for a variety of genetic, environmental and developmental histories. “Mitochondrial flashes have an amazing power to predict the remaining lifespan in animals,” says study lead Meng-Qiu Dong, a geneticist who studies ageing in the Caenorhabditis elegans worm at the National Institute of Biological Sciences in Beijing. “There is truth in the mitochondrial theory of ageing.”
The mitochondria are organelles that power the cells of plants, animals and other eukaryotic organisms. During energy production, they produce reactive oxygen molecules, such as free radicals, that can cause stress and damage the mitochondria. Although mitochondria break down over time, the mitochondrial theory of ageing, first proposed2 in 1972, remains controversial and unproven. For instance, some long-lived organisms, such as naked mole rats, endure with high levels of oxidative damage. Nevertheless, many scientists think that mitochondria remain the primary drivers of ageing.
A new credit card-sized device could analyze a biopsy and help diagnose pancreatic cancer in a matter of minutes.
Pancreatic cancer is a particularly devastating disease. At least 94 percent of patients will die within five years, and in 2013 it was ranked as one of the top 10 deadliest cancers.
Routine screenings for breast, colon, and lung cancers have improved treatment and outcomes for patients with these diseases, largely because the cancer can be detected early.
But because little is known about how pancreatic cancer behaves, patients often receive a diagnosis when it’s already too late.
A new low-cost device could help pathologists diagnose pancreatic cancer earlier and faster. The prototype can perform the basic steps for processing a biopsy, relying on fluid transport instead of human hands to process the tissue.
“This new process is expected to help the pathologist make a more rapid diagnosis and be able to determine more accurately how invasive the cancer has become, leading to improved prognosis,” says Eric Seibel, research professor of mechanical engineering and director of the Human Photonics Laboratory at the University of Washington.
Seibel and colleagues presented their initial results this month at the SPIE Photonics West conference and recently filed a patent for this first-generation device and future technology advancements.
Gluten may not be the only wheat protein that can make people sick
Two years ago, at the recommendation of a nutritionist, I stopped eating wheat and a few other grains. Within a matter of days the disabling headaches and fatigue that I had been suffering for months vanished. Initially my gastroenterologist interpreted this resolution of my symptoms as a sign that I perhaps suffered from celiac disease, a peculiar disorder in which the immune system attacks a bundle of proteins found in wheat, barley and rye that are collectively referred to as gluten. The misdirected assault ravages and inflames the small intestine, interfering with the absorption of vital nutrients and thereby causing bloating, diarrhea, headaches, tiredness and, in rare cases, death. Yet several tests for celiac disease had come back negative. Rather my doctors concluded that I had nonceliac “gluten sensitivity,” a relatively new diagnosis. The prevalence of gluten sensitivity is not yet clear, but some data suggest it may afflict as many as 6 percent of Americans, six times the number of people with celiac disease.
Pain sensitivity is controlled by a genetic "dimmer switch", which can be re-set, UK scientists have discovered.
Twins sharing 100% of genes have different pain thresholds, which can potentially be altered by lifestyle or medication, say researchers at King's College, London.
The study could lead to new painkillers or lifestyle interventions, they report in Nature Communications.
One in five of the population suffers from acute or chronic pain.
Lead researcher Dr Jordana Bell said the potential to regulate genes involved in pain sensitivity "is very exciting and could lead to a more effective pain relief treatment for patients suffering with chronic pain".
Sensitivity to pain is complex, with wide individual variation. Previous studies have suggested about half of the influence is explained by genes.
To identify levels of sensitivity to pain, scientists tested 25 pairs of identical twins using a heat probe placed on the arm.
Identical twins share 100% of their genes; therefore any difference between identical twins must be due to their environment or changes affecting the function of their genes.
Illumina, the biggest maker of genomic sequencing machines, say they’ve broken the “sound barrier” of sequencing. Their latest machine can transcribe 18,000 human genomes a year for $1,000 per genome—a mark dreamed of for over a decade.
When the human genome’s three billion molecular pairs were first fully transcribed (or sequenced) in 2003, it was deemed a seminal accomplishment, but one seemingly destined to be repeated only rarely. The project’s cost totaled $2.7 billion, and the first genomes were hundreds of millions of dollars apiece.
It was around that time that the $1,000 genome was first targeted. Why $1,000? Well, it’s a nice, round, pretty much arbitrary number—a sort of mile marker set by researchers. If ever it gets that cheap, scientists thought, we’ll be able to do anything.