Tuesday, September 4, 2012

Singapore scientists discover potential drug for brain cancer

SINGAPORE - Scientists in Singapore have identified a biomarker of the most lethal form of brain tumours in adults.

This discovery could potentially prevent the progression and relapse of the brain tumour.

The biomarker (called glioblastoma multiforme) is found in cancer stem cells. A*STAR Scientists found that when they depleted the biomarker with a potential drug, the cancer cells were completely destroyed.

A*STAR said this is an important breakthrough as current therapies such as gamma radiation and surgical methods proved to be inadequate in treating these brain tumours, which tend to re-grow from cancer stem cells and become extremely lethal.

Chief Scientist at A*STAR, Prof Sir David Lane, added: "These findings will facilitate the translation of basic research into clinical applications such as targeted drug design to treat brain cancer."

This research was conducted by scientists at A*STAR's Institute of Medical Biology in collaboration with A*STAR's Bioinformatics Institute (BII), and clinical collaborators from Medical University of Graz, Austria, and National University of Singapore.

The research findings were published last month in the scientific journal, Cell Reports from Cell Press. CHANNEL NEWSASIA

Blood sugar in normal range too can shrink brain

Blood sugar in normal range too can shrink brain
Even blood sugar in normal range may shrink brain 

New research has found that people whose blood sugar is on the high end of the normal range may be at greater risk of brain shrinkage that occurs with ageing and diseases such as dementia.

"Numerous studies have shown a link between type 2 diabetes and brain shrinkage and dementia, but we haven't known much about whether people with blood sugar on the high end of normal experience these same effects," said study author Nicolas Cherbuin, PhD, with Australian National University in Canberra.

The study involved 249 people age 60 to 64 who had blood sugar in the normal range as defined by the World Health Organization. The participants had brain scans at the start of the study and again an average of four years later.

Those with higher fasting blood sugar levels within the normal range and below 6.1 mmol/l (or 110 mg/dL) were more likely to have a loss of brain volume in the areas of the hippocampus and the amygdala, areas that are involved in memory and cognitive skills, than those with lower blood sugar levels. A fasting blood sugar level of 10.0 mmol/l (180 mg/dL) or higher was defined as diabetes and a level of 6.1 mmol/l (110 mg/dL) was considered impaired, or prediabetes.

After controlling for age, high blood pressure, smoking, alcohol use and other factors, the researchers found that blood sugar on the high end of normal accounted for six to 10 percent of the brain shrinkage.

"These findings suggest that even for people who do not have diabetes, blood sugar levels could have an impact on brain health," Cherbuin said.

"More research is needed, but these findings may lead us to re-evaluate the concept of normal blood sugar levels and the definition of diabetes," he noted.

The study has been published in the print issue of Neurology, the medical journal of the American Academy of Neurology.

Obesity affects kids’ brain power, hits academics

LONDON: Overweight children are more likely to struggle with academics because being obese can affect their brain power, a new study has found. Researchers from the New York University found that children showing physical changes due to being obese, such as high blood pressure, higher levels of bad cholesterol and resistance to the blood sugar controlling hormone, insulin, had poorer scores on thinking tests, the Telegraph said.

The study compared 49 children with metabolic syndrome, a collection of at least three health problems associated with obesity which can include a large waist, low good choelsterol, high blood fats, high blood pressure and insulin resistance which is a pre-cursor to type 2 diabetes.

The researchers concluded that even a few years of problems with metabolism may cause brain complications. The study found that those classified as having metabolic syndrome showed significantly lower maths and spelling scores, as well as decreased attention span and mental flexibility.

Maths scores were ten points lower on average in the metabolic syndrome group and spelling scores were four points lower. There was also a tendency towards lower overall IQ but memory was not affected.

They also found differences in brain structure and volume, with the metabolic syndrome groups showing a smaller hippocampus which is involved in the learning and recall of new information, and other changes. The children were all from similar socio-economic backgrounds, the same age and at the same school grade.

Heavy drinking may 'rewire' the brain

Red red wine: A woman tastes red wine during the annual Vinaria 2009 international wine fair in the town of Plovdiv in Bulgaria.
A new US study -- claimed to be the first of its kind -- finds that "heavy alcohol use actually rewires brain circuitry," according to a September 2 university press release. 

The research found both a physical and a chemical connection between the abuse of alcohol, high levels of anxiety, and post traumatic stress disorder.

Thomas Kash, Ph.D., and his team from the University of North Carolina School of Medicine tested two groups of mice. One group of mice was given doses of alcohol roughly equivalent to double the legal driving limit while the other served as the control group.

Then, both groups were trained to avoid a bell tone using a small electric shock, and then were later exposed to the bell tone with no electric shock.

According to the findings, the mice that consumed alcohol demonstrated high levels of anxiety and stress, as well as showed differences in the prefrontal cortex area of their brains. "Basically, our research shows that chronic exposure to alcohol can cause a deficit with regard to how our cognitive brain centers control our emotional brain centers," noted the researchers.

The study was published online on September 2 in the journal Nature Neuroscience.

In a similar study on rats from 2010, alcohol exposure during adolescence was found to alter the body's ability to respond to stress later in life. Because problems regulating stress are associated with behavioral and mood disorders, the findings indicate that binge drinking as a teen could lead to increased risk of anxiety or depression in adulthood.

Brain doesn't allow math, memory to mix

Brain doesn't allow math, memory to mix
Brain doesn't allow math, memory to mix

There is a limit to multi-tasking after all. The brain is not wired to allow you to balance your chequebook while introspecting, say researchers who have practically wire-tapped a hard-to-reach region of the brain.

The research showed that groups of nerve cells in a structure called the posterior medial cortex, or PMC, are strongly activated during a recall task such as trying to remember whether you had coffee yesterday. However, these groups of nerve cells are also just as strongly suppressed when you're engaged in solving a math problem.

The PMC, situated roughly where the brain's two hemispheres meet, is of great interest to neuroscientists because of its central role in introspective activities, the journal "Proceedings of the National Academy of Sciences", reports.

"This brain region is famously well-connected with many other regions that are important for higher cognitive functions," said Josef Parvizi, associate professor of neurology and neurological sciences at the Stanford University Medical Centre. "But it's very hard to reach. It's so deep in the brain that the most commonly used electrophysiological methods can't access it."

Parvizi and his Stanford colleagues found a way to directly and sensitively record the output from this ordinarily anatomically inaccessible site in human subjects, according to a Stanford statement.

By doing so, they learned that particular clusters of nerve cells in the PMC that are most active when you are recalling details of your own past are strongly suppressed when you are performing mathematical calculations. Parvizi co-authored the study with postdoctoral scholars Brett Foster and Mohammed Dastjerdi.

Much of our understanding of what roles different parts of the brain play has been obtained by techniques such as functional magnetic resonance imaging, which measures the amount of blood flowing through various brain regions as a proxy for activity in those regions.

But changes in blood flow are relatively slow, making functional magnetic resonance imaging a poor medium for listening in on the high-frequency electrical bursts (approximately 200 times per second) that best reflect nerve-cell firing.

For this study, the Stanford scientists employed a highly sensitive technique to demonstrate that introspective and externally focused cognitive tasks directly interfere with one another, because they impose opposite requirements on the same brain circuitry.