Thursday, September 20, 2012

Alzheimer`s sabotages brain wiring?


Alzheimer`s sabotages brain wiring?
Washington: Alzheimer`s could actually sabotage the working of several of the brain`s networks, says a study.

Beau Ances, assistant professor of neurology, Washington University School of Medicine in St. Louis, who led the study said: "Communications within and between networks are disrupted, but it doesn`t happen all at once."

"There`s even one network that has a momentary surge of improved connections before it starts dropping again.

"That`s the salience network, which helps you determine what in your environment you need to pay attention to," added Ances, The Journal of Neuroscience reported.

Ances and colleagues analyzed brain scans of 559 subjects.

Some of these subjects were cognitively normal, while others were in the early stages of very mild to mild Alzheimer`s disease.

 Scientists found that all of the networks they studied eventually became impaired during the initial stages of Alzheimer`s, according to a university statement.

Scientists also examined Alzheimer`s effects on a brain networking property known as anti-correlations.

Researchers identify networks by determining which brain areas frequently become active at the same time, but anti-correlated networks are noteworthy for the way their activities fluctuate: when one network is active, the other network is quiet.

This ability to switch back-and-forth between networks is significantly diminished in participants with mild to moderate Alzheimer`s disease.

The default mode network, previously identified as one of the first networks to be impaired by Alzheimer`s, is a partner in two of the three pairs of anti-correlated networks scientist studied.

"There are, however, a number of additional networks besides the default mode network that become active when the brain is idling and could tell us important things about Alzheimer`s effects," said Ances.

It`s not practical to use these network breakdowns to clinically diagnose Alzheimer`s disease, Ances notes, but they may help track the development of the disease and aid efforts to better understand its spread through the brain.

Ances plans to look at other markers for Alzheimer`s disease in the same subjects, such as levels in the cerebrospinal fluid of amyloid beta, a major component of Alzheimer`s plaques.

Second person dies from 'brain-eating amoeba': confirmed

The child who died of brain abscess in Ho Chi Minh City was actually killed by “brain- eating amoeba” (Naegleria fowleri).

This was confirmed by Tran Thanh Duong, Deputy head of the Preventive Medicine Agency under the Ministry of Health, on September 19. He said the tested samples proved positive for amoeba Naegleria fowleri.

The MoH has asked HCM City to send a detailed report on the case.

Earlier on July 30, , the Ho Chi Minh City Hospital for Tropical Diseases received a 25-year-old patient from Phu Yen, who was the first identified victim of Naegleria fowleri.

So far, Vietnam has had two people killed by brain eating amoeba. However, Duong said, this is a single case, not epidemics.

Primary amoebic meningoencephalitis is a fatal disease but it is rare and can be avoidable.

 

According to experts, the amoeba lives predominately in the warm bodies of freshwater such as lakes and rivers in tropical and subtropical climates. It grows best at a temperature of 46 degrees Celsius, but it has also been found to survive at higher temperatures of 50-56 degrees Celsius. It invades the brain through the nostrils.

To avoid the disease, the Preventive Medicine Agency warns people not to bathe and swim in high-risk areas.

If they swim at swimming-pools, ponds, lakes and streams, they should minimize water from getting into their noses. After bathing or swimming, they should clean their noses by nasal antiseptic, it says.

If they have some symptoms like a headache, fever, nausea, or vomiting, they should immediate go to clinics for prompt diagnosis and treatment.

Meow meow: The party drug that fries your brain

Nightclub Meow meow is causing significant memory loss.

IT'S cheap, it's easy to find, and it's more addictive than cocaine. But experts warn meow meow (or Drone, among other names) is no party drug - it's literally frying your brain.

Meow meow, Drone and MCAT are street names for mephedrone, a synthetic psychoactive drug that is also found in so-called "Bath Salts".

It's been on the party scene for a number of years in Australia and it's estimated that tens of thousands of revellers dabble in the off-white power.

It's said to produce a similar but more powerful high than either ecstasy or cocaine and is dangerously addictive. Yet the dangers of this relatively new and unknown drug are only just beginning to surface.

Researchers from the University of Sydney have found compelling evidence that mephedrone can give users significant memory loss, the long-term effects of which aren't yet fully understood.

Craig Motbey, the leader of the controlled testing on rats, says meow meow is similar to amphetamine and huge numbers of people have been taking it for years.

"It exploded so fast and so wide," he told news.com.au.

"[But] we know virtually nothing about the drug. Now there's a big push to find out if it's doing damage.
"It might be something that causes subtle damage that builds up, but we don't realise anything's wrong until a couple of years later when we have tens of thousands of fried brains."

Disturbing research
Mr Motbey's research confirms the fears of anti-drug campaigners. You mightn't be able to convince people to ditch recreational drugs, but they might take notice if they realise the damage it's causing.

What sounded the alarm was a simple memory test called the Novel Object Recognition Test. It works like this: A rat, given a dose of the drug, spends time in a fixed area with two identical objects (let's call them A and A). The rat is taken away, then brought back later to spend time with one object the same (A) and one entirely new object (B). A rat with a normal, healthy memory would only ever spend time investigating object B.

"Rats are naturally curious critters," Mr Motbey said. "If you put a new object in front of them, they'll spend all their time checking out the new thing.

"If they spend equal time with both things (one new and one old), then that's a clear sign of memory damage – which confirmed earlier theories about mephedrone."

Mr Motbey refers to an earlier uncontrolled study in the UK, where mephedrone users were brought in a month apart and given standard cognitive tests. The results showed some evidence of memory impairment.
"When you take the drug you get a massive wave of euphoria from serotonin, which then goes away," Mr Motbey added.

"Then there's a persistent dopamine hook that motivates people to re-dope. Mephedrone is extremely addictive. So people are getting this short-term high, the major thing driving people to take the drug, but then they're re-dosing regularly to get that initial hit back."

‘As bad as any drug'
The latest research figures show mephedrone usage in Australia is down two percentage points from 2011 in 2010. But it's still a significant problem.

Steve Patton, the acting commander of the NSW Drug Squad, said there haven't been many seizures of mephedrone but that certainly didn't mean the drug was free from risks.

"People shouldn't be taking it. It's a drug that's just as bad other drugs," he told news.com.au
"It doesn't surprise me that it does have ill-effects for people's health."

Louise, a young woman from Bondi Beach who'd dabbled with other party drugs before, says she regularly took meow meow around two to three years ago. Why?

"It was a lot stronger than pills or other drugs with a bigger high and it was cheaper," she told news.com.au.
"You can sniff it or you can eat it. It used to be about $100 per gram, which compared to coke is much cheaper.

"It gives you more of a buzz than cocaine. It's more like taking a pill, and in terms of the effects it was slightly different."

Breaking bad
Louise says it's not as readily available these days and admits, although she didn't experience major side effects, she's noticed lapses in her memory.

"How significant the effects of the memory damage, we just don't know. The research hasn't been done," Mr Motbey adds.

"We don't know what's causing the memory damage. We looked at the brains - and they were exactly the same. It's a subtle change, it's not immediately obvious."

"Hopefully we can get the word out to users that this is not a harmless, innocuous drug, it can do damage to you."

If meow meow is shut down then another, potentially more dangerous drug will inevitably pop up in its place. A drug we know nothing about.

"Modern chemistry has become so flexible you can make virtually anything," Mr Motbey added.
"A new drug comes out, the authorities ban it, and crack down on the supply. Then another drug comes out, the authorities ban it, crack down on the supply.

"It only takes moving a carbon atom from one place to another to change a drug from harmless and fun to absolutely lethal. It's just a matter of time before the drug-taking community hits on something incredibly dangerous."

Baby who suffered massive stroke after 'ticking time bomb' blood clot burst in brain makes miracle recovery

     * Jacob was born with a group of malformed blood vessels in his brain, which burst when he
        was two weeks old 
     * Parents could only watch and wait as surgeons battled to save him. They were told he might 
        never walk 
     * Doctors told family Jacob had a healthy brain in February this year 

No stopping him: Jacob Edwards took his first steps just after his first birthday 

Jacob Edwards took his first steps just after his first birthdayA baby who suffered a massive stroke after a 'ticking time bomb' of malformed blood vessels burst in his brain, has made a miraculous recovery.

Jacob Edwards fell ill when he was just two weeks old. He was rushed to hospital where surgeons had to perform a risky operation to remove a blood clot from his brain to reduce the pressure.

However, they were unable to remove all of it because it was too deep in Jacob’s brain. His parents Hayley Leon and Lee Edwards, from Coventry, were warned it could burst again and their son may be left with with brain damage.

But doctors were left stunned when a brain scan showed the Arteriovenous malformation - or AVM - had vanished. Now Jacob, 15 months, has beat the odds by learning to walk and talk - something his parents feared he may never do.

Hayley, 30, said: 'It’s amazing. We’re so proud of him. Not a day goes by when I don’t think about what happened. It could have been so different. We were very close to losing him. Jacob seemed healthy when he was born in July last year.

 But when he was two weeks old, he woke up screaming and vomiting. The couple, who also have two older sons, Callum, 11, and five-year-old Jack, immediately took him to University Hospital, Coventry, where doctors thought he had gastroenteritis. Hayley said: 'Jacob was getting worse by the hour.

He was slipping in and out of consciousness. Lee noticed his left eye was lifeless. He asked the doctors to check it and that’s when they knew something was seriously wrong. They did a CT scan and told us they had found a bleed on his brain.

Lee and I didn’t know what to say. It’s not something that happens to you. It happens to other people. We were in total shock.' Jacob was placed on a life support machine before being rushed to Birmingham Children’s Hospital for more specialist care.

Full time mother Hayley said: 'A special ambulance came to pick him up. We weren’t allowed to go with him because there wasn’t enough room. 'It was horrible leaving him. I just wanted to be with him and to make him better. 'When we got there, they took him for an MRI scan. We were taken into a side room and the surgeon came to see us. After his operation: Surgeons didn't manage to remove all of the AVM, but the rest disappeared by itself After his operation: Surgeons didn't manage to remove all of the AVM, but the rest disappeared by itself

Jacob's brain before the operation: The malformed area can be seen bottom rightWe had to sign a consent form for emergency surgery. It said the main risk was death but without surgery, he would die. My heart was breaking as the word death was mentioned a lot. Lee likes to keep his emotions to himself but he was the most upset.
He kept saying: ‘he can’t leave us yet.’ He was really panicking. But it was out of our hands so we just had to trust the surgeon.

Doctors explained to the couple they still didn’t know what had caused the bleed but that they needed to remove it and reduce the pressure in his brain immediately to stop any further damage.

 Amazingly, Jacob survived the six-hour operation but he remained in a critical condition in intensive care. Jacob's brain before the operation: The malformed area can be seen bottom right Hayley said: 'A nurse brought us to see him. It was horrible. It didn’t look like him. His head was really swollen and so were his eyes.

He had a tube coming out of his head to drain all the fluid from his brain. He had so many wires coming out of him I was scared to touch him.

(Pictured is Jacob in hospital)A scan showed the operation had been a success but surgeons were unable to remove all of the AVM. Three days later, Jacob was taken off his life support machine to see if he could breathe on his own. To everyone’s amazement, he took his first breaths unaided and was later moved to the high dependency unit, where he continued to make progress.

Due to the stroke, Jacob suffered weakness on his left side so severe he couldn’t even hold his head up and he needed intensive physiotherapy. After two weeks in hospital, doctors were so pleased with Jacob’s progress, he was discharged.

Hayley said: 'I was so scared to bring him home as at this time he still had the AVM inside his brain and there was a very high chance of it bleeding again. I didn’t sleep and didn’t leave the house for weeks. We had to go back and forth to hospital for scans, which was awful as he had to be put to sleep.

They had to check his brain for any damage. In February this year, Jacob had an angiogram, where a special dye is used to take pictures of blood flow to the brain.
Jacob with mum Hayley and dad Lee

Hayley said: 'The doctor came to see us and said it had gone. He told us Jacob had a healthy brain. He was gob-smacked and so were we. But he was still having difficulty lifting his head and he couldn’t crawl. At his development check, we were told he probably had cerebral palsy and he may not walk. We didn’t know what the future held for our brave boy.'

But three days after his first birthday, Jacob took his first steps Now there is no stopping him and he continues to amaze his parents and doctors.

Hayley said: 'He’s going from strength to strength and is reaching all his milestones. He’s so determined. I can’t thank the staff at both hospitals enough for saving my baby’s life. They are my heroes.'

Jacob Jacob’s neurosurgeon, Mr Desiderio Rodrigues, from Birmimgham Children’s Hospital said: 'Jacob was in a very poor state in coma when he was presented to the hospital and had to be intubated and ventilated prior to transfer.
Neurosurgeon Mr Desiderio Rodrigues, from Birmimgham Childrens Hospital, who performed life-saving surgery on Jacob
The scan showed a large blood clot in the back of his brain. It was obstructing the flow of the cerebro spinal fluid, which travels from the brain to the spine. I performed an operation to relieve the pressure and then remove the clot from the back of the brain. 'I spoke to the parents prior to the operation and told them it was a high risk operation.

The child could even bleed profusely and die during surgery, as the emergency scan had not identified the cause for the bleed. 'There was no choice but as a life saving measure to take the risk and operate. 'During surgery I found a leash of abnormal blood vessels which were the cause of the clot. 'I only removed part of it and follow up MRI scans have showed whatever was left has now gone.

The angiogram has confirmed that Jacob has no residual AVM.

'We are very pleased with his progress.'

UK scientists make breakthrough in new method of brain tumour diagnosis

UK scientists have made a breakthrough in a new method of brain tumour diagnosis, offering hope to tens of thousands of people.

Researchers, led by Professor Francis Martin of Lancaster University, have shown that infrared and Raman spectroscopy - coupled with statistical analysis - can be used to tell the difference between normal brain tissue and the different tumour types that may arise in this tissue, based on its individual biochemical-cell 'fingerprint'.

Spectroscopy is a technique that allows us to analyse light by breaking it into its component parts and studying the resulting pattern or spectrum.

Currently, when surgeons are operating to remove a brain tumour it can be difficult to spot where the tumour ends and normal tissue begins.

But new research published online in Analytical Methods this month has shown it is possible to spot the difference between diseased and normal tissue using Raman spectroscopy - a type of spectroscopy which works effectively on living tissue, giving accurate results in seconds.

This is a key development which means it is now theoretically possible to test living tissue during surgery, helping doctors to remove the complete tumour whilst preserving intact adjacent healthy tissue.

The fingerprinting technique was also able to identify whether the tumours arose in the brain or whether they were secondary cancers arising from an unknown primary site. This is a key development which could help reveal previously undetected cancer elsewhere in the body, improving patient outcomes.

Professor Francis Martin said: "These are really exciting developments which could lead to significant improvements for individual patients diagnosed with brain tumours.

We and other research teams are now working towards a sensor which can be used during brain surgery to give surgeons precise information about the tumour and tissue type that they are operating on."

The information obtained by this method can be combined with conventional methods, for example immunohistochemistry, to diagnose and grade brain tumours to allow for more accurate planning and execution of surgery and/or radiation therapy.

This offers more potential for individualised treatment and better long-term survival.

Eye tracking can detect brain disorders: experts

Following the movement of eyes could allow doctors to make quick, accurate diagnoses for disorders like autism and schizophrenia, experts have claimed.

Eye tracking, which records where subjects focus when watching visual displays, could diagnose brain disorders more accurately than subjective questionnaires or medical examinations do, researchers believe.
To make sense of all that people see, the brain filters huge amounts of visual information, fills in gaps and focuses on certain objects.

That complex task uses many mental circuits, so differences in what people choose to look at - differences so subtle that only a computer can spot them - could provide unprecedented insight into common neurological problems, Livescience reported.

"Eye tracking is a great way to assess somebody's spontaneous attention and preference. That's really fundamental to who you are as a person," said Karen Pierce, a researcher at the University of California, San Diego, Autism School of Excellence.

Pierce's team recently created a one-minute screening test to identify autism in high-risk kids. Toddlers watched two videos play simultaneously — one of people doing yoga, and another of moving geometric shapes.

Typically developing children focus on people, while kids with autism, who suffer from social and language deficits tend to look more at the shapes, the researchers said.

The test could identify 40 per cent of those with autism, but it doesn't wrongly flag toddlers who don't have the disorder, Pierce told the website.

Another researcher Jennifer Wagner from Children's Hospital in Boston, is comparing the gaze patterns of low-risk children and siblings of those with autism, who have a 20 per cent chance of developing the disorder.

Wagner's team studies babies between 6 months and 12 months old to try to detect autism sooner than the typical diagnoses, which are made around age 2.

"If a screening tool catches kids younger, when their neural connections are still changing rapidly, maybe you can start retraining the brain before it gets solidified in a way that's maladaptive," Wagner said.

Human Brains Share Consistent Genetic Blueprint

TEHRAN (FNA)- Researchers reported that human brains share a consistent genetic blueprint and possess enormous biochemical complexity.


The findings stem from the first deep and large-scale analysis of the vast data set publicly available in the Allen Human Brain Atlas.

The results of this study are based on extensive analysis of the Allen Human Brain Atlas, specifically the detailed all-genes, all-structures survey of genes at work throughout the human brain. This dataset profiles 400 to 500 distinct brain areas per hemisphere using microarray technology and comprises more than 100 million gene expression measurements covering three individual human brains to date. Among other findings, these data show that 84% of all genes are expressed somewhere in the human brain and in patterns that are substantially similar from one brain to the next.

"This study demonstrates the value of a global analysis of gene expression throughout the entire brain and has implications for understanding brain function, development, evolution and disease," said Ed Lein, Ph.D., Associate Investigator at the Allen Institute for Brain Science and co-lead author on the paper. "These results only scratch the surface of what can be learned from this immense data set. We look forward to seeing what others will discover."

Key Findings
The results of this study show that, despite the myriad personalities and cognitive talents seen across the human population, our brains are more similar to one another than different. Individual human brains share the same basic molecular blueprint, and deeper analysis of this shared architecture reveals several further findings:
Neighboring regions of the brain's cortex -- the wrinkly outer rind -- are more biochemically similar to one another than to more distant brain regions, which has implications for understanding the development of the human brain, both during the lifespan and throughout evolution.

The right and left hemispheres show no significant differences in molecular architecture. This suggests that functions such as language, which are generally handled by one side of the brain, likely result from more subtle differences between hemispheres or structural variation in size or circuitry, but not from a deeper molecular basis.

Despite controlling a diversity of functions, ranging from visual perception to planning and problem-solving, the cortex is highly homogeneous relative to other brain regions. This suggests that the same basic functional elements are used throughout the cortex and that understanding how one area works in detail will uncover fundamentals that apply to the other areas, as well.

In addition to such global findings, the study provides new insights into the detailed inner workings of the brain at the molecular level -- the level at which diseases unfold and therapeutic drugs take action.

84% of all genes are expressed, or turned on, somewhere in the human brain.

Many previously uncharacterized genes are turned on in specific brain regions and localize with known functional groups of genes, suggesting they play roles in particular brain functions.

Synapse-associated genes -- those related to cell-to-cell communication machinery in the brain -- are deployed in complex combinations throughout the brain, revealing a great diversity of synapse types and remarkable regional variation that likely underlies functional distinctions between brain regions.

"The tremendous variety of synapses we see in the human brain is quite striking," said Seth Grant, FRSE, Professor of Molecular Neuroscience at the University of Edinburgh and collaborating author on the study. "Mutations in synaptic genes are associated with numerous brain-related disorders, and thus understanding synapse diversity and organization in the brain is a key step toward understanding these diseases and developing specific and effective therapeutics to treat them."