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Treeless Tropics, More Disease-Carrying Mosquitoes?

THURSDAY, Nov. 2, 2017 (HealthDay News) — Deforestation doesn't just strip the landscape. In tropical regions, it may also lead to more disease-carrying mosquitoes, University of Florida researchers say. "Converting pristine tropical forests into areas for agriculture or other uses creates a habitat for the mosquitoes that transmit human diseases," lead study author Nathan Burkett-Cadena said in a university news release. He's an assistant professor of entomology. The scientists don't say why those mosquitoes might thrive without extensive tree coverage, but they note that deforested areas are warmer and drier than similar pristine forests. For their report, the researchers analyzed 17 studies from around the world. They found a strong link between deforestation in tropical habitats and higher concentrations of mosquitoes that carry diseases transmittable to people. Almost 57 percent of mosquito species in deforested areas were confirmed carriers of human disease, compared with about 28 percent of mosquito species in forested areas, the investigators said. They also found that mosquito species capable of carrying multiple human diseases favored deforested habitats. These include Aedes aegypti mosquitoes, which transmit the dengue, West Nile, yellow fever and Zika viruses. "The last couple of decades have seen an increase in efforts looking into the association between deforestation and specific diseases," said study co-author Dr. Amy Vittor. "Here we're taking a global view, comparing the distribution of mosquito species capable of carrying disease in deforested and forested areas in the tropics," added Vittor, an assistant professor in the division of infectious diseases and global medicine. The findings were published recently in the journal Basic and Applied Ecology. More information The World Health Organization has more on mosquito-borne diseases. Let's block ads! (Why?) Original Article

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Are Artery-Opening Stents for Chest Pain a Waste of Time?

THURSDAY, Nov. 2, 2017 (HealthDay News) — With findings that some experts believe could change cardiovascular care, a new study suggests that the placebo effect of stents in heart patients with chest pain may be far more pronounced than thought. That could mean that drug therapy alone, rather than the pricey, artery-opening devices, is all that's needed for certain patients, the researchers said. "The most important reason we give patients a stent is to unblock an artery when they are having a heart attack. However, we also place stents into patients who are getting pain only on exertion caused by narrowed, but not blocked, arteries. It's this second group that we studied," explained lead author Rasha Al-Lamee, from the National Heart and Lung Institute at Imperial College London. The study included 200 patients with stable angina who received six weeks of intensive drug treatment for their angina. After that, they either received a stent or underwent a simulated procedure where no stent was implanted. Patients who received stents did not have more improvements in angina or quality of life than those who did not receive a stent. Angina is the medical term for chest pain. It is typically caused by the build-up of fatty plaques in the arteries. The study was published online Nov. 2 in The Lancet medical journal, to coincide with a presentation at a cardiology meeting in Denver. "Surprisingly, even though the stents improved blood supply, they didn't provide more relief of symptoms compared to drug treatments, at least in this patient group," Al-Lamee said in a university news release. "While these findings are interesting and deserve more attention, they do not mean that patients should never undergo the [stent] procedure for stable angina. It may be that some patients opt to have an invasive procedure over taking long-term medication to control their symptoms," she added. The researchers plan further analysis of their data, to determine if there are subgroups of patients whose angina improves more after stenting. "It seems that the link between opening a narrowing coronary artery and improving symptoms is not as simple as everyone had hoped," Al-Lamee said. "This is the first trial of its kind, and [it] will help us to develop a greater understanding of stable angina, a disease which affects so many of our patients every day." Writing in a commentary that accompanied the report, two cardiologists said the "landmark" study has implications that "are profound and far-reaching." "First and foremost, the results of [the study] show unequivocally that there are no benefits" for the use of stents compared to drug therapy for people who have stable angina, said Dr. David Brown, of Washington University School of Medicine in St. Louis, and Dr. Rita Redberg, of the University of California, San Francisco. In fact, based on the new findings, Brown and Redberg believe that stents may not be useful in these cases even when a patient's angina fails to get better after medications are used. "Based on these data, all cardiology guidelines should be revised to downgrade the recommendation for [stents] in patients with angina," whether or not they also received drug therapy, the doctors said. Their reasoning? According to Brown and Redberg, each year over a half-million patients in the United States and Europe undergo stent treatment — and a sizeable minority will experience potentially dangerous complications that can include heart attack, kidney injury, stroke and even death. Subjecting these patients to those risks when no benefit can be achieved is irresponsible, they said. Doctors need to focus more on drug therapy and efforts at "improving the lifestyle choices" of many heart patients — things like bad diets, lack of exercise and smoking, the editorialists concluded. Several companies — including Boston Scientific, Medtronic and Abbott Laboratories — sell the devices, and inserting them costs from $11,000 to $41,000 at hospitals in the United States. More information The American Heart Association has more on angina. Let's block ads! (Why?) Original Article

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Sugary Drinks Could Break Your Heart

THURSDAY, Nov. 2, 2017 (HealthDay News) — If you're a fan of sodas, fruit juices and sugary sports drinks, you're probably not doing your heart any favors. A new review suggests that regularly quenching your thirst with sugar-sweetened beverages not only contributes to your risk of gaining weight, it also ups your chances of developing type 2 diabetes and metabolic syndrome, a cluster of conditions that raises your risk of heart disease. "Some studies found that consuming as few as two servings of sugar-sweetened beverages a week was linked to [an increased risk of metabolic syndrome, diabetes and heart disease and stroke]," said study senior author Faadiel Essop, a professor at Stellenbosch University in South Africa. "Others found that drinking at least one sugar-sweetened beverage per day was associated with elevated blood pressure," he said, and added that even more alarmingly, some studies found that sugary drinks could raise blood pressure in teenagers. Metabolic syndrome occurs when you have three or more of the following risk factors for heart disease: abdominal obesity, high levels of triglycerides (a type of blood fat), reduced levels of HDL (the good) cholesterol, elevated blood sugar, and higher than normal fasting blood sugar levels (but not yet high enough to be considered diabetes), according to the American Heart Association. The review included 36 studies that looked at the effects of sugary drinks on heart and metabolic health. The studies were done within the past 10 years. The studies had varied findings, according to the researchers. But most suggested an association between drinks containing sugar and the development of metabolic syndrome. The majority of the studies also looked at people who had more than five sugary drinks a week. It's not clear exactly how these drinks increase the odds of metabolic syndrome, Essop said. But certainly excess consumption of sugary drinks is linked to a higher waist circumference — a factor in metabolic syndrome — and weight gain. Such drinks have also been tied to decreased insulin sensitivity (a risk for diabetes), inflammation, abnormal cholesterol and high blood pressure, he said. "Those consuming sugary drinks do not feel as full as those who ate solid foods, even though they had the same amount of calories," Essop noted, and that lack of satiety may then cause people to eat or drink more. Dr. Joel Zonszein, director of the clinical diabetes center at Montefiore Medical Center in New York City, said that fruit offers a good example. "If you eat an apple, you get full much easier. In addition to sugar, an apple has a lot of fiber and the satiety is much better. But when you have a glass of apple juice, you're getting the sugar from three to four apples and no fiber. That's a much more concentrated dose of sugar that will spike the blood sugar level," he explained. Dr. William Cefalu, chief scientific, medical and mission officer from the American Diabetes Association, said the studies included in this review were observational studies, which are a good starting point when looking at medical problems, but they cannot prove a cause-and-effect relationship. "What we can be sure of, however, is that sugar-sweetened beverages provide a substantial amount of excess calories with no nutritional benefit, and excess calories beyond what is normally needed by the body to maintain normal activities, in turn, does lead to weight gain," Cefalu said. And excess weight is a significant risk factor for type 2 diabetes, as well as many heart disease risk factors. "At the end of the day, drinking water is the best form of hydration for all people — with or without diabetes," he said. One important exception, Cefalu noted, is anyone with diabetes — particularly those treated with insulin — whose blood sugar is low. In that case, it's crucial to quickly raise blood sugar levels to prevent serious complications. A sugar-sweetened beverage such as juice or soda can do that quite well. The study was published Nov. 2 in the Journal of the Endocrine Society. More information To learn more about metabolic syndrome, visit the American Heart Association. Let's block ads! (Why?) Original Article

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Are You Sure That’s What the Doctor Said About Your Leukemia?

THURSDAY, Nov. 2, 2017 (HealthDay News) — The stress of a frightening leukemia diagnosis may impede clear doctor-patient communication, a new study suggests. Patients undergoing chemotherapy treatment for acute myeloid leukemia (AML) tend to view their illness and prognosis through a different lens from their doctors, researchers say. Investigators found that patients are inclined to overestimate their risk of dying due to treatment and, at the same time, overestimate their chances for a full cure. "Patients with AML face very challenging treatment decisions that are often placed upon them within days after being diagnosed," said senior study author Dr. Areej El-Jawahri. "Because they face a grave decision, they need to understand what the risks of treatment are versus the possibility of a cure," said El-Jawahri, an assistant professor of medicine at Massachusetts General Hospital in Boston. Adult AML is a type of cancer generally seen in older people in which the bone marrow makes abnormal white blood cells, red blood cells or platelets. Chemotherapy, radiation, drug therapy or a stem cell transplant can be used as treatment, according to the Cleveland Clinic. Investigators focused on 100 AML patients. Half were in intensive care for four to six weeks, while the other half were mostly treated as outpatients. On average, patients were 71 years old. Roughly three days after starting treatment, the patients and their doctors completed surveys. More than 6 out of 10 patients said it was "somewhat likely" they would die because of treatment, and almost 30 percent said it was "extremely likely" they would die. However, 8 in 10 of the cancer doctors said that scenario was very unlikely. Another survey one month later revealed other misunderstandings. While 90 percent of patients believed it was either somewhat or very likely they would ultimately be cured, three-quarters of the doctors thought it was somewhat or very unlikely that a cure was in the offing. The gap was especially wide between doctors and outpatients. Researchers found 44 percent of outpatients thought they were very likely achieve a cure, but none of the doctors shared that view. The five-year survival rate for people with AML is approximately 27 percent, according to the American Cancer Society. The findings were recently presented at a meeting of the American Society of Clinical Oncology and other groups, in San Diego. "There were several very important factors we were not able to capture in our study, including what was actually discussed between patients and their oncologists, and whether patients simply misunderstood or misheard the information conveyed to them," El-Jawahri said in a meeting news release. Still, the urgency of decision-making required with AML may contribute to differences in perception, the researchers said. Previous work with patients treated for other types of cancer didn't uncover such pronounced distortions. Research presented at meetings is usually considered preliminary until published in a peer-reviewed medical journal. More information There's more on other cancer perceptions at PACE. Let's block ads! (Why?) Original Article

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Patients’ Gut Bugs May Play Role in Cancer Care

THURSDAY, Nov. 2, 2017 (HealthDay News) — The type of bacteria that cancer patients harbor in the gut might affect their odds of responding to certain treatments, two early studies hint. The research, in humans and mice, adds to evidence that gut bacteria play a key role in the immune system. But experts stressed it's too soon to make recommendations to cancer patients — including whether they should take "probiotic" supplements. Both studies looked at whether there's a link between patients' gut bacteria and their responses to newer cancer drugs called PD-1 inhibitors. The drugs, which include Keytruda (pembrolizumab) and Opdivo (nivolumab), work by freeing up the immune system to attack cancer cells. The drugs are approved for several cancers, including advanced cases of melanoma, lung, bladder and stomach cancers. In one study, researchers focused on 112 patients with advanced melanoma, the deadliest form of skin cancer. The investigators found that those who'd responded to PD-1 therapy tended to have a gut "microbiome" that was distinct from those of patients who did not respond. Those who'd responded generally had more diversity in their bacteria, plus higher concentrations of common bacteria called Ruminococcus and Faecalibacterium. Still, the researchers said the findings do not prove that those bacteria improve the odds of doing well on PD-1 therapy. "Only a clinical trial can show that. This needs to be tested," said senior researcher Dr. Jennifer Wargo, an associate professor at University of Texas M.D. Anderson Cancer Center in Houston. However, the findings build on evidence of a "clear link between the gut microbiome and immune function," she said. The "microbiome" refers to the trillions of bacteria and other microbes that dwell in the human body. Studies have found that the diversity of those bugs — particularly in the gut — is linked to the risks of various health conditions, including those related to immune function. In general, studies have found, the more diversity in the gut microbiome, the better. Wargo's study involved a group of melanoma patients who'd responded to a PD-1 inhibitor — meaning their cancer had stabilized or regressed for at least six months — and a group that did not respond. Overall, the responders showed an "abundance" of Ruminococcus and Faecalibacterium. In contrast, the non-responders had a high concentration of Bacteroidales bacteria. To test whether the microbes might have a direct influence on treatment response, the researchers transplanted gut bacteria from the patients into lab mice. Those animals also responded better to PD-1 therapy, versus mice that had transplants from non-responding patients, according to the report. In the second study, French researchers focused on 249 patients treated with a PD-1 inhibitor for lung, kidney or urinary tract cancers. Just over one-quarter had taken antibiotics to treat an infection shortly before or after starting PD-1 treatment. (Antibiotics are drugs that kill bacteria). Overall, those antibiotic patients had lower survival odds. Plus, 69 percent of patients who responded to PD-1 treatment had detectable amounts of bacteria called Akkermansia muciniphila, versus 34 percent of patients who did not respond. It all raises "exciting possibilities," Wargo said. Namely, could manipulating the gut microbiome improve the chances of responding to cancer treatment? But there are plenty of unanswered questions. For one, "We don't really know what constitutes a 'favorable' microbiome," Wargo noted. So there is no way to tell cancer patients whether any probiotic might benefit them. In fact, she said, if patients were to take a random supplement, it might end up causing harm. In addition, there also needs to be more research into gut bacteria and responses to other cancer therapies, Wargo added. Dr. Nikhil Khushalani specializes in treating skin cancer at Moffitt Cancer Center, in Tampa, Fla. He cautioned that the study findings are a "first step," but also a "very intriguing" one. Khushalani said the findings raise the possibility of testing patients' stool samples to see who has a greater likelihood of responding to PD-1 therapy. "That could help us in truly tailoring treatment," he suggested. Then there's the possibility of actually altering patients' microbiomes — whether through probiotics or even fecal transplants, Khushalani added. Like Wargo, he cautioned patients against self-treating with probiotics, given the unknowns. "But that could be where we're heading," Khushalani said. "Hopefully, this will open the door to even more research in this arena." The new research appears in the Nov. 3 issue of Science. More information The American Cancer Society has more on cancer immunotherapy. Let's block ads! (Why?) Original Article

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What Food Gets People’s Attention? Junk Food, by Far

THURSDAY, Nov. 2, 2017 (HealthDay News) — If cookies, pizza and potato chips seem to pull you in, you're not alone. A new study finds that images of junk food are, indeed, more distracting than those of healthy food. The researchers also found, though, that just a few tastes of junk food can significantly reduce its appeal. "We wanted to see if pictures of food, particularly high-fat, high-calorie food, would be a distraction for people engaged in a complicated task," said co-author Howard Egeth, a professor in the department of psychological and brain sciences at Johns Hopkins University in Baltimore. The researchers showed the pictures to 18 participants, most of them undergraduate students. "We showed them carrots and apples, and it slowed them down," Egeth said in a university news release. "We showed them bicycles and thumb tacks, and it slowed them down. But when we showed them chocolate cake and hot dogs, these things slowed them down about twice as much." The researchers then repeated the experiment with 18 new participants, but first gave them two small candy bars before they began their task. This time, the study found that images of junk food were no more distracting than pictures of healthy food or nonfood items. The findings were published online Oct. 26 in the journal Psychonomic Bulletin and Review. The researchers believe the study findings highlight people's built-in bias for fatty, sugary foods and confirm the old saying that you shouldn't grocery shop when you're hungry. Meet the Johns Hopkins researchers who describe their study More information The American Heart Association offers healthy eating advice. Let's block ads! (Why?) Original Article

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Gene Therapy, New Drug Battle a Rare But Deadly Disease in Kids

WEDNESDAY, Nov. 1, 2017 (HealthDay News) — Babies born with a previously untreatable degenerative nerve disease now have two fresh sources of hope for their future. Two innovative new therapies for spinal muscular atrophy (SMA) type 1 have proven highly effective in clinical trials, researchers report. Babies with SMA are born without the gene that promotes production of survival motor neuron (SMN) protein. Without this protein, nerve cells in the spinal cord and brain stem stop working and start to die off. These babies slowly lose the ability to move their arms and legs. Those with the most severe form, SMA type 1, eventually lose the ability to breathe on their own and rarely survive beyond 2 years of age. Two research groups say they've produced breakthrough therapies for these children. First, a new genetic treatment employed a DNA-loaded virus to replace the missing SMN1 gene with a fresh, healthy copy of the gene. Second, an already-approved drug called nusinersen (Spinraza) was used to promote production of the crucial nerve protein by a backup gene called SMN2. Both approaches increased survival in babies with SMA and preserved or improved their motor function, the researchers said. "These are the first realistic treatment options for SMA," said Dr. Ans van der Ploeg. She is chair of the Center for Lysosomal and Metabolic Diseases at Erasmus MC University in Rotterdam, the Netherlands. Both therapies aim to increase production of SMN protein in the motor neurons and thereby improve the survival and function of motor neurons, she said. This leads to better muscle and respiratory function and survival, added van der Ploeg, who wrote an editorial accompanying the two clinical trial reports. About one in every 11,000 babies is born with SMA, and six in 10 of them have type 1, said Dr. Richard Finkel. He is chief of neurology at Nemours Children's Hospital in Orlando, Fla., and lead researcher of the nusinersen clinical trial. The gene therapy treatment was tested in 15 babies with SMA type 1. All received one intravenous dose of a genetically engineered virus containing the new copy of the SMN gene. The virus is named AVXS-101. This was a phase 1 trial to test safety. "We are trying to replace SMN1 with enough gene that works in enough nerve cells to change function," said lead researcher Dr. Jerry Mendell, director of neuromuscular disorders and neurosciences at Nationwide Children's Hospital in Columbus, Ohio. All 15 patients treated with AVXS-101 are still alive, Mendell said, and some are thriving. Higher doses produced better responses. "All the patients in the trial have improved with the exception of one," Mendell said. "We have patients living out past three years now. And we had patients who actually could walk and run and play." Nusinersen was tested in 80 babies at 31 hospitals as part of a phase III trial prior to its 2016 approval. "The drug is kind of novel," Finkel said. "It's not your standard off-the-shelf pharmacy kind of drug. It's similar to a little piece of DNA." The drug targets the SMN2 gene, a backup gene to the SMN1 gene missing in these babies. It is injected into the spinal fluid. Patients undergo four "loading doses" via lumbar punctures within the first two months, and receive maintenance doses every four months, Finkel said. Nusinersen amps up protein production by the SMN2 gene, potentially halting progression of nerve damage. In the trial, 41 percent of infants who received the earliest treatment with nusinersen and 51 percent of infants in the final analysis experienced stable or improved motor function, the researchers reported. Babies treated with nusinersen also were more likely to survive. The risk of death was 63 percent lower in the nusinersen group compared with the control group, the findings showed. Results were so promising that the clinical trial was halted early so the control group could receive nusinersen, the study authors said. "This study shows the drug has a clinically meaningful response with a higher likelihood of improved survival and motor function," Finkel said. Nusinersen, made by Biogen, is available for treatment now. AVXS-101 will proceed to broader clinical trials involving more children at multiple hospitals, Mendell said. Neither treatment had any clinically significant side effects, according to the researchers. The treatments do not constitute a full cure for children who have already developed symptoms of SMA. However, both research teams hope that kids treated before symptoms arise won't suffer any degenerative nerve loss. Finkel said, "If we can get these babies before they show these signs of weakness, I think that's going to give the best chance for the most robust response, possibly even a cure." Van der Ploeg added that younger, less severely affected patients had a better chance of a good response in the trials. Also, while the gene therapy pilot trial results are promising, more data are required, she noted. The nusinersen trial was paid for by Biogen and the drug's developer, Ionis Pharmaceuticals. The AVXS-101 trial received funding from AveXis, developer of the designer virus. Results of the studies were published in the Nov. 2 issue of the New England Journal of Medicine. More information For more on spinal muscular atrophy, visit the Nemours Foundation. Let's block ads! (Why?) Original Article

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Liposuction May Ease Limb Swelling in Cancer Patients

WEDNESDAY, Nov. 1, 2017 (HealthDay News) — Liposuction may help people with lymphedema — a painful, disfiguring swelling of the arms, hands, legs or feet. Harvard researchers used the surgical technique to remove fat from just underneath the skin in three people with the condition. Two of the patients had lymphedema as a side effect of cancer treatment. The other one had a naturally developing form of lymphedema. In all three cases, there was improvement in the lymphedema after liposuction, the researchers said. And the improvement appears to be more effective and lasting than expected. One patient has had more than five years of follow-up. "Liposuction is extremely effective at removing fat from underneath the skin, which makes the arm or leg smaller," explained study author Dr. Arin Greene, director of the lymphedema program at Boston Children's Hospital. "And the new data show that the surgery improves lymphatic flow and increases quality of life. It actually allows the underlying lymphatic system to move the fluid," he said. But Greene did have a word of caution. "This is not a cure. It improves lymphatic flow, but people still need to take conservative measures, such as wearing compression garments," he noted. Greene said cancer probably causes about 99 percent of lymphedema cases. Another 1 percent have it due to a developmental problem. The reason people get lymphedema after cancer treatment is because when cancer spreads to lymph nodes, those nodes need to be removed. In this process, part of the lymph vessels attached to the node are also removed. Lymph nodes and vessels are part of the body's immune system. When removed, the body's natural drainage system for lymph fluid is disrupted and fluid builds up, sometimes to extreme levels, according to the American Cancer Society. Radiation therapy also can damage nodes and vessels or cause scarring that blocks drainage. Lymphedema can be very uncomfortable and cause a feeling of heaviness. Skin can feel tight. Wounds may heal more slowly, and lymphedema can cause reduced flexibility, the cancer society says. About 200 million people have lymphedema worldwide, according to the study authors. Treatment typically includes wearing compression garments and getting a special type of massage that helps promote fluid drainage. The study patients who had liposuction only had the procedure on an affected limb. They didn't have liposuction on their hands or feet. However, the two patients who had liposuction on their arm also saw improvement in their hand, and the one who had liposuction on her leg had improvement in the lymphedema affecting her foot. Greene said this was unexpected. He has several theories as to why liposuction was more effective than expected, though he emphasized that none are yet proven. One theory is that by removing the fat, pressure is taken off of the remaining lymph nodes and vessels, allowing them to function better. Another theory is that the fat may make fluid, too, so removing it might mean less overall fluid. Dr. Douglas Roth, chief of plastic and reconstructive surgery at Northern Westchester Hospital in Mount Kisco, N.Y., was impressed with the study's results. "As a plastic surgeon, I was taught to stay away from areas with lymphedema. The tissue is already compromised, making concerns about complications more significant. These areas need to be treated very, very carefully," said Roth, who was not involved with the study. "But this is definitely a breakthrough in thinking about the treatment of this problem, and it's a brand new procedure that could be very helpful," Roth said. He added that while the procedure hasn't been used for lymphedema in the United States, it has been used in Europe and Australia for about 10 years. Still, Roth said he'd want to see a larger trial on a U.S. population before he would consider it. Greene said insurance covered all three procedures. Roth said insurance companies would likely pay for liposuction done for a medical reason, such as lymphedema. When done on a purely cosmetic basis, liposuction is about $7,000 to $9,000 for the surgeon's fee and the operating room time, Roth estimated. The study was published Nov. 1 in the New England Journal of Medicine. More information To learn more about lymphedema, visit the American Cancer Society. Let's block ads! (Why?) Original Article

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Long Spaceflights Could Put Pressure on the Brain

WEDNESDAY, Nov. 1, 2017 (HealthDay News) — The brains of astronauts who spend months in space appear to shift upward inside their skulls by the time they return to Earth, a new study finds. The repercussions, if any, are uncertain for now, researchers said. It's not clear how quickly the brain might settle back into its rightful place once Earth's gravity has taken hold, said lead researcher Dr. Donna Roberts. But one concern is this: If the brain moves upward, it could compress a major vein that drains blood from the head — possibly increasing pressure within the skull. And in fact, it's already known that some astronauts have returned from the International Space Station with vision problems. NASA has dubbed the phenomenon "visual impairment and intracranial pressure" syndrome, or VIIP. Roberts said her team suspects the brain's upward shift can help explain VIIP — though it's too early to say for sure. The findings raise other questions, according to Roberts, an associate professor at the Medical University of South Carolina in Charleston. Specifically, what might happen to the human brain during deeper space travel? That's a possibility in the not-too-distant future, as NASA has laid out plans for getting humans to Mars by the 2030s. "If we see these brain changes after a few months on [the space station]," Roberts said, "what might happen on a mission to Mars?" A journey to Mars can take three to six months. Then, to reduce travel time between the Earth and Mars, the two planets need to be aligned favorably, which occurs approximately every two years, Roberts explained. The study findings, published Nov. 2 in the New England Journal of Medicine, are based on MRI brain scans of 34 astronauts. Eighteen had been on space station missions, averaging 165 days; the rest had been on shuttle missions, averaging 14 days. All the astronauts had brain scans taken before the mission, then again about a week after they'd returned. The researchers were able to look for certain structural changes in a subgroup of 18 astronauts. It turned out that all 12 space station astronauts showed an upward shift in the brain, versus none of the six who'd returned from a short-term mission. Similarly, the space station astronauts were much more likely to show a narrowing in the cerebrospinal fluid spaces at the top of the brain. Rachael Seidler, a professor at the University of Florida in Gainesville, is leading a NASA-sponsored study looking into the effects of prolonged spaceflight on movement, thinking and behavior. She described the dynamics of what the latest study showed in basic terms: The Earth's gravitational pull normally draws fluids downward in the body. But in the microgravity of space, more cerebrospinal fluid can build up around the brain — which pushes it up. "In a sense, the brain is getting a little squished," Seidler said. More work is needed to know what it all could mean. "How long do the [brain] changes last?" Seidler said. "Are there effects on behavior or physical performance?" Astronauts have, of course, been traveling to and from space for decades. And scientists have long studied the effects on the heart, bones and other body systems, Roberts said. The brain, however, has gotten little attention. That started changing in recent years, Roberts said, with the emergence of VIIP — which has cropped up almost exclusively after long-term missions. But the questions go beyond VIIP, according to Seidler. For example, she said, what happens when the brain is no longer getting normal sensory information from the legs for months? What are the effects of having the vestibular (balance) system thrown off by being in microgravity 24/7? Studying those questions, Seidler said, could help in better understanding earthly conditions, too — such as cases where people are on prolonged bed rest. This postflight MRI video shows an upward shift of the brain and narrowing of cerebrospinal spaces at the top of the brain of a NASA astronaut aboard the International Space Station. Video courtesy Dr. Donna Roberts. More information For more on the effects of spaceflight on the human body, visit NASA. Let's block ads! (Why?) Original Article

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