Domain: medicalxpress.com
Stories and comments across the archive that link to medicalxpress.com.
Stories · 18
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Human Images From World's First Total-Body Scanner Unveiled (medicalxpress.com)
An anonymous reader quotes a report from Medical Xpress: EXPLORER, the world's first medical imaging scanner that can capture a 3-D picture of the whole human body at once, has produced its first scans. The brainchild of UC Davis scientists Simon Cherry and Ramsey Badawi, EXPLORER is a combined positron emission tomography (PET) and X-ray computed tomography (CT) scanner that can image the entire body at the same time. Because the machine captures radiation far more efficiently than other scanners, EXPLORER can produce an image in as little as one second and, over time, produce movies that can track specially tagged drugs as they move around the entire body.
EXPLORER will have a profound impact on clinical research and patient care because it produces higher-quality diagnostic PET scans than have ever been possible. EXPLORER also scans up to 40 times faster than current PET scans and can produce a diagnostic scan of the whole body in as little as 20-30 seconds. Alternatively, EXPLORER can scan with a radiation dose up to 40 times less than a current PET scan, opening new avenues of research and making it feasible to conduct many repeated studies in an individual, or dramatically reduce the dose in pediatric studies, where controlling cumulative radiation dose is particularly important. -
Lavender's Soothing Scent Could Be More Than Just Folk Medicine (nytimes.com)
An anonymous reader writes: In a study published Tuesday in the journal Frontiers in Behavioral Neuroscience, [physiologist and neuroscientist Hideki Kashiwadani] and his colleagues found that sniffing linalool, an alcohol component of lavender odor, was kind of like popping a Valium (Warning: source may be paywalled; alternative source). It worked on the same parts of a mouse's brain, but without all the dizzying side effects. And it didn't target parts of the brain directly from the bloodstream, as was thought. Relief from anxiety could be triggered just by inhaling through a healthy nose. Their findings add to a growing body of research demonstrating anxiety-reducing qualities of lavender odors and suggest a new mechanism for how they work in the body. Dr. Kashiwadani believes this new insight is a key step in developing lavender-derived compounds like linalool for clinical use in humans.
In this study, they exposed mice to linalool vapor, wafting from filter paper inside a specially made chamber to see if the odor triggered relaxation. Mice on linalool were more open to exploring, indicating they were less anxious than normal mice. And they didn't behave like they were drunk, as mice on benzodiazepines, a drug used to treat anxiety, or injected with linalool did. But the linalool didn't work when they blocked the mice's ability to smell, or when they gave the mice a drug that blocks certain receptors in the brain. This suggested that to work, linalool tickled odor-sensitive neurons in the nose that send signals to just the right spots in the brain -- the same ones triggered by Valium. -
'Mindful People' Feel Less Pain, Study Finds (medicalxpress.com)
An anonymous reader quotes a report from Medical Xpress: Ever wonder why some people seem to feel less pain than others? A study conducted at Wake Forest School of Medicine may have found one of the answers -- mindfulness. The researchers analyzed data obtained from a study published in 2015 that compared mindfulness meditation to placebo analgesia. In this follow-up study, Zeidan sought to determine if dispositional mindfulness, an individual's innate or natural level of mindfulness, was associated with lower pain sensitivity, and to identify what brain mechanisms were involved. In the study, 76 healthy volunteers who had never meditated first completed the Freiburg Mindfulness Inventory, a reliable clinical measurement of mindfulness, to determine their baseline levels. Then, while undergoing functional magnetic resonance imaging, they were administered painful heat stimulation.
Whole brain analyses revealed that higher dispositional mindfulness during painful heat was associated with greater deactivation of a brain region called the posterior cingulate cortex, a central neural node of the default mode network. Further, in those that reported higher pain, there was greater activation of this critically important brain region. The default mode network extends from the posterior cingulate cortex to the medial prefrontal cortex of the brain. These two brain regions continuously feed information back and forth. This network is associated with processing feelings of self and mind wandering. The study provided novel neurobiological information that showed people with higher mindfulness ratings had less activation in the central nodes (posterior cingulate cortex) of the default network and experienced less pain. Those with lower mindfulness ratings had greater activation of this part of the brain and also felt more pain, Zeidan said. -
New Anti-Cancer Drug Put Cancers To Sleep In Mice -- Permanently (medicalxpress.com)
"Australian scientists have taken a 'major step forward' in the world of cancer research," reports ABC (the national broadcaster of Australia). Long-time Slashdot reader Artem Tashkinov quotes an announcement from the Walter and Eliza Hall Institute of Medical Research: In a world first, Melbourne scientists have discovered a new type of anti-cancer drug that can put cancer cells into a permanent sleep, without the harmful side-effects caused by conventional cancer therapies.
Published today in the journal Nature, the research reveals the first class of anti-cancer drugs that work by putting the cancer cell to sleep -- arresting tumour growth and spread without damaging the cells' DNA.
The new class of drugs could provide an exciting alternative for people with cancer, and has already shown great promise in halting cancer progression in models of blood and liver cancers, as well as in delaying cancer relapse.
One of the lead researchers says the new compounds "had already shown great promise in preclinical testing." -
Researchers Find Antidepressants Increase Risk of Death (medicalxpress.com)
Artem Tashkinov shares a report from Medical Xpress: Antidepressant medications, most commonly prescribed to reduce depression and anxiety, increase the risk of death, according to new findings by a McMaster-led team of researchers. It's widely known that brain serotonin affects mood, and that most commonly used antidepressant treatment for depression blocks the absorption of serotonin by neurons. It is less widely known, though, that all the major organs of the body -- the heart, kidneys, lungs, liver -- use serotonin from the bloodstream. Antidepressants block the absorption of serotonin in these organs as well, and the researchers warn that antidepressants could increase the risk of death by preventing multiple organs from functioning properly.
Interestingly, the news about antidepressants is not all bad. The researchers found that antidepressants are not harmful for people with cardiovascular diseases such as heart disease and diabetes. This makes sense since these antidepressants have blood-thinning effects that are useful in treating such disorders. Unfortunately, this also means that for most people who are in otherwise good cardiovascular health, antidepressants tend to be harmful. The study has been published in the journal Psychotherapy and Psychosomatics. -
WHO Issues a List of 12 Most Worrying Drug-Resistant Bacteria (medicalxpress.com)
Artem Tashkinov quotes a report from Medical Xpress: The World Health Organization has issued a list of the top dozen bacteria most dangerous to humans, warning that doctors are fast running out of treatment options. WHO said the most-needed drugs are for germs that threaten hospitals, nursing homes and among patients who need ventilators or catheters. The agency said the dozen listed resistant bacteria are increasingly untreatable and can cause fatal infections; most typically strike people with weakened immune systems. At the top of WHO's list is Acinetobacter baumannii, a group of bacteria that cause a range of diseases from pneumonia to blood or wound infections. In recent years, health officials have detected a few patients resistant to colistin, the antibiotic of last resort. So far, doctors have been able to treat them with other drugs. But experts worry that the colistin-resistant bacteria will spread their properties to other bacteria already resistant to more commonly used antibiotics, creating germs that can't be killed by any known drugs. -
Increased Smartphone Screen-Time Is Associated With Lower Sleep Quality, Says Study (medicalxpress.com)
A new study from the University of California is the latest to show that increased smartphone screen-time can lower one's quality of sleep, which can lead to various negative health conditions such as obesity, diabetes and depression. Medical Xpress reports: Christensen and colleagues sought to test the hypothesis that increased screen-time may be associated with poor sleep by analyzing data from 653 adult individuals across the United States participating in the Health eHeart Study. Participants installed a smartphone application which recorded their screen-time, defined as the number of minutes in each hour that the screen was turned on, over a 30-day period. They also recorded their sleeping hours and sleep quality. The researchers found that each participant totaled an average of 38.4 hours over this period, with smartphones being activated on average for 3.7 minutes in each hour. Longer average screen-time was associated with poor sleep quality and less sleep overall, particularly when smartphones were used near participants' bedtime. The authors state that their study is the first to measure smartphone exposure prospectively, but caution that the study also had some important limitations, including the self-selection of study participants and self-reporting of data. The study has been published in the journal PLOS ONE. -
Nurses In Australia Face Punishment For Promoting Anti-Vaccination Messages Via Social Media (medicalxpress.com)
HughPickens.com writes: Medical Express reports that nurses and midwives promoting anti-vaccination messages in Australia could face punishment including being slapped with a caution and having their ability to practice medicine restricted. Serious cases could be referred to an industry tribunal, where practitioners could face harsher penalties such as having their registration suspended or cancelled. The Nursing and Midwifery Board of Australia released the vaccination standards in response to what it described as a small number of nurses and midwives promoting anti-vaccination via social media. The statement also urges members of the public to report nurses or midwives promoting anti-vaccination. Promoting false, misleading or deceptive information is an offense under national law and is prosecutable by the Australian Health Practitioner Regulation Agency. "The board will consider whether the nurse or midwife has breached their professional obligations and will treat these matters seriously," the statement said. However Dr. Hannah Dahlen, a professor of midwifery at the University of Western Sydney and the spokeswoman for the Australian College of Midwives, worries the crackdown may push people with anti-vaccination views further underground. "The worry is the confirmation bias that can occur, because people might say: 'There you go, this is proof that you can't even have an alternative opinion.' It might in fact just give people more fuel for their belief systems." -
Replacing Butter With Vegetable Oils Doesn't Decrease Risk of Heart Disease, Says Study (medicalxpress.com)
An anonymous reader writes: A research team led by scientists at the UNC School of Medicine and the National Institutes of Health has unearthed more evidence that casts doubt on the traditional "heart healthy" practice of replacing butter and other saturated fats with corn oil and other vegetable oils high in linoleic acid. The findings, reported today in the British Medical Journal, suggest that using vegetable oils high in linoleic acid might be worse than using butter when it comes to preventing heart disease, though more research needs to be done on that front. This latest evidence comes from an analysis of previously unpublished data of a large controlled trial conducted in Minnesota nearly 50 years ago, as well as a broader analysis of published data from all similar trials of this dietary intervention. The analyses show that interventions using linoleic acid-rich oils failed to reduce heart disease and overall mortality even though the intervention reduced cholesterol levels. In the Minnesota study, participants who had greater reduction in serum cholesterol had higher rather than lower risk of death. Two things to note about the study: 75% of the participants left in less than a year (perhaps not uncommon, the study doesn't explain why these people left); the vegetable oils mentioned in the article are not necessarily the most commonly used (which are oils made of olive, sunflower, coconut, and palm). -
Researchers Develop Cancer-Targetting Hybrid Molecule (medicalxpress.com)
New York researchers have developed a hybrid molecule that can target cancer cells, which they believe shows promise in the fight against breast cancer. The team created a composite nanoparticle that can transport chemotherapeutic agents, in a technique that more than doubled the uptake of an anti-inflammatory compound that inhibits cancer cell growth when directly applied to a tumor. The composite nanoparticle "can load up with these drugs, carry them to malignant cells, and unload them where they can do the most damage with the least amount of harm to the patient," according to a statement from the NYU Tandon School of Engineering, with one of the researchers summarizing it as a hybird molecule that "can carry higher payloads, enabling it to deliver more drug." -
Neural Mechanisms In Mouse Brains Indicate We Actively Forget As We Learn (medicalxpress.com)
An anonymous reader writes from an article on MedicalXpress: They say that once you've learned to ride a bicycle, you never forget how to do it. But new research suggests that while learning, the brain is actively trying to forget. "This is the first time that a pathway in the brain has been linked to forgetting, to actively erasing memories," says Cornelius Gross, who led the work at EMBL. At the simplest level, learning involves making associations, and remembering them. Working with mice, Gross and colleagues studied the hippocampus, a region of the brain that's long been know to help form memories. Information enters this part of the brain through three different routes. As memories are cemented, connections between neurons along the 'main' router become stronger. When they blocked this main route, the scientists found that the mice were no longer capable of learning a Pavlovian response -- associating a sound to a consequence, and anticipating that consequence. But if the mice had learned that association before the scientists stopped information flow in that main route, they could still retrieve that memory. This confirmed that this route is involved in forming memories, but isn't essential for recalling those memories. The latter probably involves the second route into the hippocampus, the scientists surmise. But blocking that main route had an unexpected consequence: the connections along it were weakened, meaning the memory was being erased. -
Neural Mechanisms In Mouse Brains Indicate We Actively Forget As We Learn (medicalxpress.com)
An anonymous reader writes from an article on MedicalXpress: They say that once you've learned to ride a bicycle, you never forget how to do it. But new research suggests that while learning, the brain is actively trying to forget. "This is the first time that a pathway in the brain has been linked to forgetting, to actively erasing memories," says Cornelius Gross, who led the work at EMBL. At the simplest level, learning involves making associations, and remembering them. Working with mice, Gross and colleagues studied the hippocampus, a region of the brain that's long been know to help form memories. Information enters this part of the brain through three different routes. As memories are cemented, connections between neurons along the 'main' router become stronger. When they blocked this main route, the scientists found that the mice were no longer capable of learning a Pavlovian response -- associating a sound to a consequence, and anticipating that consequence. But if the mice had learned that association before the scientists stopped information flow in that main route, they could still retrieve that memory. This confirmed that this route is involved in forming memories, but isn't essential for recalling those memories. The latter probably involves the second route into the hippocampus, the scientists surmise. But blocking that main route had an unexpected consequence: the connections along it were weakened, meaning the memory was being erased. -
"Advanced Life Support" Ambulances May Lead To More Deaths
HughPickens.com writes Jason Kane reports at PBS that emergency treatments delivered in ambulances that offer "Advanced Life Support" for cardiac arrest may be linked to more death, comas and brain damage than those providing "Basic Life Support." "They're taking a lot of time in the field to perform interventions that don't seem to be as effective in that environment," says Prachi Sanghavi. "Of course, these are treatments we know are good in the emergency room, but they've been pushed into the field without really being tested and the field is a much different environment." The study suggests that high-tech equipment and sophisticated treatment techniques may distract from what's most important during cardiac arrest — transporting a critically ill patient to the hospital quickly.
Basic Life Support (BLS) ambulances stick to simpler techniques, like chest compressions, basic defibrillation and hand-pumped ventilation bags to assist with breathing with more emphasis placed on getting the patient to the hospital as soon as possible. Survival rates for out-of-hospital cardiac arrest patients are extremely low regardless of the ambulance type with roughly 90 percent of the 380,000 patients who experience cardiac arrest outside of a hospital each year not surviving to hospital discharge. But researchers found that 90 days after hospitalization, patients treated in BLS ambulances were 50 percent more likely to survive than their counterparts treated with ALS. Not everyone is convinced of the conclusions. "They've done as much as they possibly can with the existing data but I'm not sure that I'm convinced they have solved all of the selection biases," says Judith R. Lave. "I would say that it should be taken as more of an indication that there may be some very significant problems here." -
Experiment Shows Caffeine Boosts Long Term Memory
An anonymous reader writes "A team of researchers at Johns Hopkins has published results demonstrating that caffeine seems to boost long-term memory. In a double-blind study, participants were shown a series of images soon after taking either a caffeine pill or a placebo; 24 hours later they were tested on a similar, but not identical, series of images. Those who took the caffeine pill were more likely to correctly classify images as being different, identical, or similar to those seen the previous day; researchers refer to this as a 'pattern separation' test. The beneficial effect of caffeine on the long-term memory of honey bees was covered by Slashdot earlier." -
Researchers Identify Genetic Systems Disrupted In Autistic Brain
hessian sends this excerpt from Medical Xpress "Autism has a strong genetic basis, but so far efforts to identify the responsible genes have had mixed results. The reason for this is that autism is influenced by many different genes, and different genes are involved in different individuals, making it hard to find the common genetic ground between patients. Now, research conducted at the Hebrew University of Jerusalem has shown that despite this fact, the different genes involved in autism tend to be involved in specific processes in the brain. This can explain, on the one hand, similarities in the behavioral symptoms of different autistics, but also the large spectrum of behaviors observed in different autistic individuals." -
Training an Immune System To Kill Cancer: a Universal Strategy
New submitter Guppy writes "A previous story reported widely in the media, and appearing both on Slashdot and XKCD, described a novel cancer treatment, in which a patient's own T-cells were modified using an HIV-derived vector to recognize and kill leukemia cells. In a follow-up publication (PDF), a further development is described which allows for a nearly unlimited choice of target antigens, broadening the types of malignancies potentially treatable with the technique (abstract)." -
'Giant' Neuron Regulates 50,000 Other Neurons
Scottingham sends this quote from PhysOrg: "A single interneuron controls activity adaptively in 50,000 neurons, enabling consistently sparse codes for odors (abstract). The brain is a coding machine: it translates physical inputs from the world into visual, olfactory, auditory, tactile perceptions via the mysterious language of its nerve cells and the networks which they form. Neural codes could in principle take many forms, but in regions forming bottlenecks for information flow (e.g., the optic nerve) or in areas important for memory, sparse codes are highly desirable. ... This single giant interneuron tracks in real time the activity of several tens of thousands of neurons in an olfactory centre and feeds inhibition back onto all of them, so as to maintain their collective output within an appropriately sparse regime. In this way, representation sparseness remains steady as input intensity or complexity varies." -
Bionic Leg Undergoing Clinical Trials
fangmcgee writes "A 'bionic' leg designed for people who have lost a lower leg is undergoing clinical trials sponsored by the US Army. The researchers hope the leg will be able to learn the patient's nerve signal patterns and be able to move in response to the patient's own muscles and nerves (abstract). Electrodes are attached to nine muscles in the thigh to detect the patterns in which the nerve signals are fired. Different patterns correspond to different intended movements. In the current stages of training, the volunteers are wired up to the electrodes and learn how to use the muscles to make a computer avatar move on screen. Results showed that all the volunteers could control the avatar’s knee and ankle movements from neural information from the thigh, with amputees achieving 91 percent accuracy of movement and the non-amputees achieving 89 percent."