Posts tagged medicine
Articles and news from the latest research reports.
New insight into SIDS deaths points to lack of oxygen
Research at the University of Adelaide has shed new light onto the possible causes of sudden infant death syndrome (SIDS), which could help to prevent future loss of children’s lives.
In a world-first study, researchers in the University’s School of Medical Sciences have found that telltale signs in the brains of babies that have died of SIDS are remarkably similar to those of children who died of accidental asphyxiation.
"This is a very important result. It helps to show that asphyxia rather than infection or trauma is more likely to be involved in SIDS deaths," says the leader of the project, Professor Roger Byard AO, Marks Professor of Pathology at the University of Adelaide and Senior Specialist Forensic Pathologist with Forensic Science SA.
The study compared 176 children who died from head trauma, infection, drowning, asphyxia and SIDS.
Researchers were looking at the presence and distribution of a protein called β-amyloid precursor protein (APP) in the brain. This “APP staining”, as it’s known, could be an important tool for showing how children have died. This is the first time a detailed study of APP has been undertaken in SIDS cases.
"All 48 of the SIDS deaths we looked at showed APP staining in the brain," Professor Byard says.
"The staining by itself does not necessarily tell us the cause of death, but it can help to clarify the mechanism.
"The really interesting point is that the pattern of APP staining in SIDS cases - both the amount and distribution of the staining - was very similar to those in children who had died from asphyxia."
Professor Byard says that in one case, the presence of APP staining in a baby who had died of SIDS led to the identification of a significant sleep breathing problem, or apnoea, in the deceased baby’s sibling.
"This raised the possibility of an inherited sleep apnoea problem, and this knowledge could be enough to help save a child’s life," Professor Byard says.
"Because of the remarkable similarity in SIDS and asphyxia cases, the question is now: is there an asphyxia-based mechanism of death in SIDS? We don’t know the answer to that yet, but it looks very promising."
This study was conducted at the University of Adelaide by visiting postdoctoral researcher Dr Lisbeth Jensen from Aarhus University Hospital, Denmark, and was funded by SIDS and Kids South Australia. The results have been published in the journal Neuropathology and Applied Neurobiology.
"This work also fits in very well with collaborative research that is currently being undertaken between the University of Adelaide and Harvard University, on chemical changes in parts of the brain that control breathing," Professor Byard says.
(Source: adelaide.edu.au)
A young man lies unconscious on the table, his head clamped firmly in place. His eyes are closed. The hair over his left temple has been shaved.
Continue reading: How a surgeon installs seizure sensors inside a skull
(Image courtesy: University of Utah, Department of Neurosurgery)
![Researchers examine metabolism in defective cells
UAlberta researchers are taking a closer look at how two metabolic pathways interact to increase the lifespan of cells with mitochondrial defects. Magnus Friis (PhD ’10) is the lead author of the study, which was published online on April 10 and will be published in the April 24 issue of Cell Reports.
Mitochondria produce energy for cells through oxidative metabolism, but the process produces toxic byproducts that can accumulate and cause defects in the cell’s mitochondria. These defects, in turn, affect the cell’s ability to generate energy and can potentially lead to cell death and are associated with aging and various neurological diseases.
Friis, a postdoctoral fellow in Mike Schultz’s biochemistry lab, examined how dietary changes at the cell level can affect cell health. He exposed normal and defective yeast cells to two different energy sources: glucose, the preferred sugar of cells, and raffinose, a natural sugar found in vegetables and whole grains.
“[The dietary intervention] is a general shift in what we’re feeding the cells to get them to do something different with their whole nutrient metabolism,” Friis noted. “There are signaling pathways that allow a cell to sense its environment and co-ordinate events to allow the cell to adapt to what’s going on. In this case, [cells are responding to] which nutrients are available.”
Friis and Schultz examined two nutrient signaling pathways called the AMPK pathway and the retrograde response. AMPK responds to energy deficits in the cell by down-regulating energy consuming processes, which are often associated with cell growth, and up-regulating energy producing processes. The retrograde response pathway is specific to the yeast used in the study and supplies key amino acids to the cell by changing the metabolic process of the mitochondria.
When activated individually, neither the AMPK pathway nor the retrograde response provided substantial benefits to cells with damaged mitochondria. When activated simultaneously, clear benefits became evident.
“We looked at the effect activating both pathways had on maintenance of cellular viability in what’s called a chronological aging experiment,” Friis said. “Even when they had defective mitochondria, the cells with the retrograde response and AMPK simultaneously activated during growth were able to live as long as cells with normal mitochondrial function.”
Working in collaboration with John Paul Glaves, a postdoctoral fellow in Bryan Sykes’ lab, and Tao Huan, a PhD student in Liang Li’s lab, Friis measured the molecules produced during the metabolic process. They found that the defective cells had higher levels of branched chain amino acids and trahelose, a carbohydrate found in yeast that can serve an energy source, similar to glycogen in human cells.
“By activating AMPK, we’ve removed certain blocks in metabolism. With the retrograde response, we’ve changed the amino acid metabolism in a way that allowed the cells to accumulate storage carbohydrates, which stabilize their function,” Friis said.
Activated AMPK and retrograde response pathways allow the cell to accumulate a storage carbohydrate, which can be metabolize normally despite mitochondrial defects that affect the cell’s metabolism. The additional energy stabilizes cell function and prevents premature cell death often caused by defects in mitochondria.
“No matter how many people are working on the problem in humans, mitochondrial disorders are too complicated to figure out the nuts and bolts without the work that Magnus is doing,” Schultz said. “This research opens the concept, a new concept on how to deal with these metabolic problems.”](http://36.media.tumblr.com/f29270201420592849dffb93598b7ba4/tumblr_n3xfsgn5To1rog5d1o1_400.jpg)
Researchers examine metabolism in defective cells
UAlberta researchers are taking a closer look at how two metabolic pathways interact to increase the lifespan of cells with mitochondrial defects. Magnus Friis (PhD ’10) is the lead author of the study, which was published online on April 10 and will be published in the April 24 issue of Cell Reports.
Mitochondria produce energy for cells through oxidative metabolism, but the process produces toxic byproducts that can accumulate and cause defects in the cell’s mitochondria. These defects, in turn, affect the cell’s ability to generate energy and can potentially lead to cell death and are associated with aging and various neurological diseases.
Friis, a postdoctoral fellow in Mike Schultz’s biochemistry lab, examined how dietary changes at the cell level can affect cell health. He exposed normal and defective yeast cells to two different energy sources: glucose, the preferred sugar of cells, and raffinose, a natural sugar found in vegetables and whole grains.
“[The dietary intervention] is a general shift in what we’re feeding the cells to get them to do something different with their whole nutrient metabolism,” Friis noted. “There are signaling pathways that allow a cell to sense its environment and co-ordinate events to allow the cell to adapt to what’s going on. In this case, [cells are responding to] which nutrients are available.”
Friis and Schultz examined two nutrient signaling pathways called the AMPK pathway and the retrograde response. AMPK responds to energy deficits in the cell by down-regulating energy consuming processes, which are often associated with cell growth, and up-regulating energy producing processes. The retrograde response pathway is specific to the yeast used in the study and supplies key amino acids to the cell by changing the metabolic process of the mitochondria.
When activated individually, neither the AMPK pathway nor the retrograde response provided substantial benefits to cells with damaged mitochondria. When activated simultaneously, clear benefits became evident.
“We looked at the effect activating both pathways had on maintenance of cellular viability in what’s called a chronological aging experiment,” Friis said. “Even when they had defective mitochondria, the cells with the retrograde response and AMPK simultaneously activated during growth were able to live as long as cells with normal mitochondrial function.”
Working in collaboration with John Paul Glaves, a postdoctoral fellow in Bryan Sykes’ lab, and Tao Huan, a PhD student in Liang Li’s lab, Friis measured the molecules produced during the metabolic process. They found that the defective cells had higher levels of branched chain amino acids and trahelose, a carbohydrate found in yeast that can serve an energy source, similar to glycogen in human cells.
“By activating AMPK, we’ve removed certain blocks in metabolism. With the retrograde response, we’ve changed the amino acid metabolism in a way that allowed the cells to accumulate storage carbohydrates, which stabilize their function,” Friis said.
Activated AMPK and retrograde response pathways allow the cell to accumulate a storage carbohydrate, which can be metabolize normally despite mitochondrial defects that affect the cell’s metabolism. The additional energy stabilizes cell function and prevents premature cell death often caused by defects in mitochondria.
“No matter how many people are working on the problem in humans, mitochondrial disorders are too complicated to figure out the nuts and bolts without the work that Magnus is doing,” Schultz said. “This research opens the concept, a new concept on how to deal with these metabolic problems.”
Stem Cells Show Promise for Stroke Recovery
Early study found they can be safely transplanted into the brain; 2 patients showed significant improvement
In an early test, researchers report they’ve safely injected stem cells into the brains of 18 patients who had suffered strokes. And two of the patients showed significant improvement.
All the patients saw some improvement in weakness or paralysis within six months of their procedures. Although three people developed complications related to the surgery, they all recovered. There were no adverse reactions to the transplanted stem cells themselves, the study authors said.
What’s more, the researchers said, two patients experienced dramatic recoveries almost immediately after the treatments.
Those patients, who were both women, started to regain the ability to talk and walk the morning after their operations. In both cases, they were more than two years past their strokes, a point where doctors wouldn’t have expected further recovery.
Severe obesity on the rise among children in the U.S.
A new study led by a University of North Carolina School of Medicine researcher finds little to cheer about in the fight against childhood obesity, despite a recent report to the contrary.
The study, published online first April 7 in JAMA Pediatrics, found that all classes of obesity in U.S. children have increased over the last 14 years. Perhaps most troubling, the study found an upward trend in the more severe forms of obesity – those in which children have a body mass index (BMI) that is 120 to 140 percent higher than their peers.
“An increase in more severe forms of obesity in children is particularly troubling,” said Asheley Cockrell Skinner, PhD, lead author of the study and assistant professor of pediatrics in the UNC School of Medicine. “Extreme obesity is more clearly associated with heart disease and diabetes risk in children and adolescents, and is more difficult to treat.”
These findings are based on a new analysis of data collected from 26,690 children ages 2-19 from 1999 to 2012 as part of the National Health and Nutrition Examination Survey (NHANES).
(Image: Getty)
Tweeting a killer migraine in real time
Not even the pain of a migraine headache keeps people from Twitter.
Over the course of a week, students collected every tweet that mentioned the word migraine. Once they cleared out the ads, the retweets and the metaphorical uses of the word, they had 14,028 tweets from people who described their migraine headaches in real time — with words such as “killer,” “the worst” (almost 15% of the tweets) and the F-word.
The Twitter users also reported the repercussions from their migraines: missing school or work, lost sleep, mood changes.
The researchers found the information to be “a powerful source of knowledge” about the headaches, because usually sufferers are providing information after the fact in clinical situations.
“The technology evolves, and our language evolves,” Dr. Alexandre DaSilva, an assistant professor at the University of Michigan School of Dentistry and lead author of the study, said Wednesday by phone. Clinical researchers’ language — such as “throbbing” or “pulsating” — might not be as apt today, to “the generation that grew up with video games.”
First UK study of ketamine for people with severe depression
The first UK study of the use of ketamine intravenous infusions in people with treatment-resistant depression has been carried out in an NHS clinic by researchers at Oxford Health NHS Foundation Trust and the University of Oxford.
'Ketamine is a promising new antidepressant which works in a different way to existing antidepressants. We wanted to see whether it would be safe if given repeatedly, and whether it would be practical in an NHS setting. We especially wanted to check that repeated infusions didn't cause cognitive problems,' explains principal investigator Dr Rupert McShane, a consultant psychiatrist at Oxford Health and a researcher in Oxford University's Department of Psychiatry.
The researchers confirmed that ketamine has a rapid antidepressant effect in some patients with severe depression who have not responded to other treatments. These are patients suffering from severe depression which may have lasted years despite multiple antidepressants and talking therapies. Although many patients relapsed within a day or two, 29% had benefit which lasted at least three weeks and 15% took over two months to relapse.
Ketamine did not cause cognitive or bladder side effects when given on up to six occasions, although some people did experience other side effects such as anxiety during the infusion or being sick. The team have now given over 400 infusions to 45 patients and are exploring ways to maintain the effect. They report their findings in the Journal of Psychopharmacology. The study was funded by National Institute for Health Research (NIHR) Research for Patient Benefit Programme.
Forget Smart Watches, ‘Smart Skin’ May Be the Next Big Thing in Wearable Computers
Parkinson’s patients could one day ditch their pills for a stretchy skin patch with a mind of its own. Using specialized sensors, the patch would monitor the wearer’s vital signs, beam the information to a doctor, and administer medication as needed. While such devices still face substantial obstacles before wide-scale implementation, two teams of researchers have announced innovations combining standard electronics with flexible materials that may bring the futuristic concept closer to reality.
Conventional electronics, such as those found in computers and smartphones, are built on stiff slabs of silicon. While durable, the design makes for bulky and uncomfortable wearable devices. Flexible electronics instead print circuits onto limber strips of silicone or plastic. The bendable base layers make devices twist and stretch when attached to the skin, but they are limited by a lack of key components such as batteries and processors that currently do not exist in flexible form.
Researchers from Seoul National University led by bioengineer Dae-Hyeong Kim have now developed a patch that automatically delivers medication to Parkinson’s patients. Parkinson’s disease is a neurological disorder that causes movement impairments such as hand tremors that require regular medication to suppress. Typically, patients take pills every few hours, leading to a spike in medication levels followed by a gradual decline that causes the tremors to return. The team’s skin patch instead supplies a series of smaller measured doses as needed by using a tremor-detecting sensor. Because the device needs to track the tremors over time, they utilized a newly invented memory format called resistive random-access memory to create the first flexible data storage for wearable devices. The new format can be used in a thin, low-power form, making it ideal for inclusion in wearable electronics.
Running, Cardio Activities in Young Adulthood May Preserve Thinking Skills in Middle Age
Young adults who run or participate in other cardio fitness activities may preserve their memory and thinking skills in middle age, according to a new study published in the April 2, 2014, online issue of Neurology®, the medical journal of the American Academy of Neurology. Middle age was defined as ages 43 to 55.
“Many studies show the benefits to the brain of good heart health,” said study author David R. Jacobs, Jr, PhD, with the University of Minnesota in Minneapolis. “This is one more important study that should remind young adults of the brain health benefits of cardio fitness activities such as running, swimming, biking or cardio fitness classes.”
Cardiorespiratory fitness is a measure of how well your body transports oxygen to your muscles, and how well your muscles are able to absorb the oxygen during exercise.
For the study, 2,747 healthy people with an average age of 25 underwent treadmill tests the first year of the study and then again 20 years later. Cognitive tests taken 25 years after the start of the study measured verbal memory, psychomotor speed (the relationship between thinking skills and physical movement) and executive function.
For the treadmill test, which was similar to a cardiovascular stress test, participants walked or ran as the speed and incline increased until they could not continue or had symptoms such as shortness of breath. At the first test, participants lasted an average of 10 minutes on the treadmill. Twenty years later, that number decreased by an average of 2.9 minutes. For every additional minute people completed on the treadmill at the first test, they recalled 0.12 more words correctly on the memory test of 15 words and correctly replaced 0.92 more numbers with meaningless symbols in the test of psychomotor speed 25 years later, even after adjusting for other factors such as smoking, diabetes and high cholesterol.
People who had smaller decreases in their time completed on the treadmill test 20 years later were more likely to perform better on the executive function test than those who had bigger decreases. Specifically, they were better able to correctly state ink color (for example, for the word “yellow” written in green ink, the correct answer was “green”).
“These changes were significant, and while they may be modest, they were larger than the effect from one year of aging,” Jacobs said. “Other studies in older individuals have shown that these tests are among the strongest predictors of developing dementia in the future. One study showed that every additional word remembered on the memory test was associated with an 18-percent decrease in the risk of developing dementia after 10 years.”
“These findings are likely to help us earlier identify and consequently prevent or treat those at high risk of developing dementia,” Jacobs said.