Archive for April, 2012


Tuesday, April 17th, 2012


Scientists at Stanford University’s School of Medicine have created nanoparticles that are able to precisely highlight brain tumors. Because the nanoparticles can be imaged in three different ways, they can be used to delineate the boundaries of tumors before and during brain surgery to ease the complete removal of tumors. The scientists have already used the nanoparticles to remove brain tumors from mice with unprecedented accuracy and hope the technique could be used on humans in the future.

“With brain tumors, surgeons don’t have the luxury of removing large amounts of surrounding normal brain tissue to be sure no cancer cells are left,” said Sam Gambhir, MD, PhD, and chair of radiology and director of the Molecular Imaging Program at Stanford. “You clearly have to leave as much of the healthy brain intact as you possibly can.”

However, removing the entire tumor while sparing normal brain tissue is nigh on impossible for even the most skillful surgeons. This is particularly true for glioblastomas, the most aggressive form of brain tumor that features rough-edges and tiny, fingerlike projections that commonly follow the paths of blood vessels and nerve tracts to infiltrate healthy tissue.

Miniscule tumor patches, called micrometastases, which are caused by the migration and replication of cells from the primary tumor, can dot otherwise healthy nearby tissue and be invisible to a surgeon’s naked eye before sprouting into new tumors.

The nanoparticles engineered in Gambhir’s lab are essentially miniscule gold balls measuring less than five-millionths of an inch in diameter – roughly one-sixtieth the diameter of a human red blood cell – that are coated with imaging reagents.

“We hypothesized that these particles, injected intravenously, would preferentially home in on tumors but not healthy brain tissue,” said Gambhir, who is also a member of the Stanford Cancer Institute. “The tiny blood vessels that feed a brain tumor are leaky, so we hoped that the spheres would bleed out of these vessels and lodge in nearby tumor material.”

Triple threat imaging

The surface coatings applied to the nanoparticles render them visible to three different imaging techniques, the first being magnetic resonance imaging (MRI). Although MRI’s are already used to indicate the location of a tumor pre-operatively, they can’t provide a perfect image of an aggressively growing tumor at the time of an operation.

The second is photoacoustic imaging involves exposing the nanoparticles to pulses of light, which is absorbed by the gold cores, resulting in the particles heating up slightly and producing detectable ultrasound signals that allow a three-dimensional image of the tumor to be computed. The scientists say that this method can be useful in guiding the removal of the bulk of a tumor during surgery because it has high depth penetration and is highly sensitive to the presence of the gold particles.

The third method is called Raman imaging, which is also being used in the SpectroPen that aims to help surgeons define the boundaries of a tumor in real-time during surgery. In this case, the coatings of the gold nanoparticles amplify the almost undetectable Raman signals given off by certain materials so they can be captured by a special microscope.

Put to the test

After demonstrating that the gold nanoparticles specifically targeted only tumor tissue, the team implanted several different types of human glioblastoma cells deep into the brains of laboratory mice. They then injected the coated gold nanoparticles into the mice’s tail veins and were able to visualize the tumors that the glioblastoma cells had spawned with all three imaging techniques.

While neither MRI nor photoacoustic imaging alone could distinguish healthy tissue from cancerous tissue at a sufficiently minute level to identify every last bit of a tumor, MRI scans provided a good image of the general shapes and location of the tumor pre-operatively, while the photoacoustic imaging provided accurate, real-time visualization of the tumors’ edges during an operation.

After clearing the bulk of the mouse’s tumor using these imaging techniques, the highly-sensitive Raman imaging was then used to flag residual micrometastases and tiny fingerlike projections remaining in adjacent healthy tissue that had been missed by visual inspection. As the study found that the Raman signals only emanated from tumor-ensconced nanoparticles, it was possible to remove these dangerous remnants.

“Now we can learn the tumor’s extent before we go into the operating room, be guided with molecular precision during the excision procedure itself and then immediately afterward be able to ‘see’ once-invisible residual tumor material and take that out, too,” said Gambhir.

Gambhir suggests that the nanoparticles’ tumor specificity, combined with their ability to heat up on photoacoustic stimulation, might give them the potential to be used to selectively destroy tumors. He added that the precision in highlighting tumors might also be used on other tumor types.

The team’s study is published online in Nature Medicine.

Source: Stanford University

Sourced & published by Henry Sapiecha


Monday, April 16th, 2012


Seizures can be very scary experiences for people who suffer from them, especially since they may sometimes result in the need for medical attention. Unfortunately, they often come on so fast that the people getting them aren’t able to get out a call for help beforehand – they simply have to ride out the seizure on their own, and hope for the best. Now, however, two new technologies may be able to help. One is a watch that alerts caregivers when it detects movements associated with seizures, while the other is a system that could stop seizures before they start, by sending electrical impulses to the brain.

A wearable alert device

The watch, known as the SmartWatch, is made by California-based tech company SmartMonitor. It can be worn 24 hours a day, and detects repetitive, excessive arm motions outside of the user’s regular movement spectrum, associated with grand mal seizures.

If they are able to, wearers can send out an alert to family members or other caregivers of their choice, simply by pressing a button on the watch. If not, within 15 to 30 seconds the watch will automatically send a Bluetooth signal to the user’s Android smartphone (which can’t be any farther than five feet away), which will in turn send that same alert to the same people. False alarms can be cancelled with the press of a button.

Afterwards, a secure record of the time, duration and geographical location of seizures can be accessed by the user, for possible onward use by health care professionals.

The SmartWatch is available in the U.S. as of today – the price has not yet been made public.

A system to stop seizures

At Baltimore’s Johns Hopkins University, meanwhile, assistant professor of biomedical engineering Sridevi V. Sarma is leading research into software that could more efficiently stop seizures before they happen.

Currently, when people are prone to seizures that don’t respond to drug treatment, they sometimes have electrodes surgically implanted in their brains. Algorithms running in an accompanying electronics package monitor the brain’s electrical activity, and cause the electrodes to administer an electrical pulse to the brain, when seizure-like activity is detected. While this setup is often effective at stopping the seizure from proceeding, it is also very prone to false alarms.

“They’re very good at detecting when a seizure is about to happen, but they also produce lots of false positives, sometimes hundreds in one day,” Sarma said of these systems. “If you introduce electric current to the brain too often, we don’t know what the health impacts might be. Also, too many false alarms can shorten the life of the battery that powers the device, which must be replaced surgically.”

The Johns Hopkins software is designed to work with systems like this, in which implanted electrodes deliver electrical pulses to a targeted location of the brain

Sarma and her team addressed this problem by analyzing the brain electrical activity of epilepsy patients, recorded before, during and after seizures. Specifically, they wanted to get a better idea of what sort of activity immediately preceded seizures. Once that activity was identified, they then trained their software to act only on it, while ignoring other types of activity that can confuse traditional systems.

When tested on recordings of the brain activity of four epilepsy patients, the system easily detected all of the actual seizures, but produced up to 80 percent less false alarms than conventional technology.

Sarma now plans on fine-tuning her software, using brain recordings from a further 100 patients. She hopes that within two to four years, it could be integrated into brain implants that could be used in clinical trials.

More information on both the SmartWatch and the Johns Hopkins software is available in the videos below.

Source: SmartMonitor, Johns Hopkins University

Sourced & published by Henry Sapiecha


Monday, April 16th, 2012

MS has a new technique for treatment says Italian doctor

Left: diagram from a medical text showing how MS affects the myelin sheathing of nerves. R...

An Italian doctor has been getting dramatic results with a new type of treatment for Multiple Sclerosis, or MS, which affects up to 2.5 million people worldwide. In an initial study, Dr. Paolo Zamboni took 65 patients with relapsing-remitting MS, performed a simple operation to unblock restricted bloodflow out of the brain – and two years after the surgery, 73% of the patients had no symptoms. Dr. Zamboni’s thinking could turn the current understanding of MS on its head, and offer many sufferers a complete cure.

Multiple sclerosis, or MS, has long been regarded as a life sentence of debilitating nerve degeneration. More common in females, the disease affects an estimated 2.5 million people around the world, causing physical and mental disabilities that can gradually destroy a patient’s quality of life.

It’s generally accepted that there’s no cure for MS, only treatments that mitigate the symptoms – but a new way of looking at the disease has opened the door to a simple treatment that is causing radical improvements in a small sample of sufferers.

Italian Dr. Paolo Zamboni has put forward the idea that many types of MS are actually caused by a blockage of the pathways that remove excess iron from the brain – and by simply clearing out a couple of major veins to reopen the blood flow, the root cause of the disease can be eliminated.

Dr. Zamboni’s revelations came as part of a very personal mission – to cure his wife as she began a downward spiral after diagnosis. Reading everything he could on the subject, Dr. Zamboni found a number of century-old sources citing excess iron as a possible cause of MS. It happened to dovetail with some research he had been doing previously on how a buildup of iron can damage blood vessels in the legs – could it be that a buildup of iron was somehow damaging blood vessels in the brain?

He immediately took to the ultrasound machine to see if the idea had any merit – and made a staggering discovery. More than 90% of people with MS have some sort of malformation or blockage in the veins that drain blood from the brain. Including, as it turned out, his wife.

He formed a hypothesis on how this could lead to MS: iron builds up in the brain, blocking and damaging these crucial blood vessels. As the vessels rupture, they allow both the iron itself, and immune cells from the bloodstream, to cross the blood-brain barrier into the cerebro-spinal fluid. Once the immune cells have direct access to the immune system, they begin to attack the myelin sheathing of the cerebral nerves – Multiple Sclerosis develops.

He named the problem Chronic Cerebro-Spinal Venous Insufficiency, or CCSVI.

Zamboni immediately scheduled his wife for a simple operation to unblock the veins – a catheter was threaded up through blood vessels in the groin area, all the way up to the effected area, and then a small balloon was inflated to clear out the blockage. It’s a standard and relatively risk-free operation – and the results were immediate. In the three years since the surgery, Dr. Zamboni’s wife has not had an attack.

Widening out his study, Dr. Zamboni then tried the same operation on a group of 65 MS-sufferers, identifying blood drainage blockages in the brain and unblocking them – and more than 73% of the patients are completely free of the symptoms of MS, two years after the operation.

In some cases, a balloon is not enough to fully open the vein channel, which collapses either as soon as the balloon is removed, or sometime later. In these cases, a metal stent can easily be used, which remains in place holding the vein open permanently.

Dr. Zamboni’s lucky find is yet to be accepted by the medical community, which is traditionally slow to accept revolutionary ideas. Still, most agree that while further study needs to be undertaken before this is looked upon as a cure for MS, the results thus far have been very positive.

Naturally, support groups for MS sufferers are buzzing with the news that a simple operation could free patients from what they have always been told would be a lifelong affliction, and further studies are being undertaken by researchers around the world hoping to confirm the link between CCSVI and MS, and open the door for the treatment to become available for sufferers worldwide.

It’s certainly a very exciting find for MS sufferers, as it represents a possible complete cure, as opposed to an ongoing treatment of symptoms. We wish Dr. Zamboni and the various teams looking further into this issue the best of luck.

Via The Globe and Mail.

Sourced & published by Henry Sapiecha


Monday, April 16th, 2012


A gun accident fifteen years ago left Richard Lee Norris without his lips, nose, and with limited movement of his mouth. Now after a marathon 36-hour surgical procedure described as “the most extensive full face transplant completed to date,” a team led by Dr. Eduardo Rodriguez at the University of Maryland has restored Mr. Norris’ quality of life.

The procedure, which goes by the technical name of “vascularized composite allograft” (VCA), took place at the R Adams Cowley Shock Trauma Center at the University of Maryland Medical Center on March 19-20 and involved over 150 nurses and professional staff.

CT scan before and after surgery (Image: University of Maryland Medical Center)

“We utilized innovative surgical practices and computerized techniques to precisely transplant the mid-face, maxilla and mandible including teeth, and a portion of the tongue,” said Dr. Rodriquez. “In addition, the transplant included all facial soft tissue from the scalp to the neck, including the underlying muscles to enable facial expression, and sensory and motor nerves to restore feeling and function. Our goal is to restore function as well as have aesthetically pleasing results.”

The achievement is the result of 10 years of research and the generosity of a anonymous donor who also saved five other lives through organ transplants – four of which also took place at the University of Maryland Medical Center.

Source: University of Maryland Medical Center

Published by Henry Sapiecha


Monday, April 16th, 2012


Although there is currently no cure for HIV, the body does already contain cells that fight the virus – the problem is, there just aren’t enough of them to completely get rid of it. In 2009, scientists at UCLA performed a proof-of-concept experiment, in which they were able to grow these CD8 cytotoxic T lymphocytes (better known as infection-fighting “T cells”) from genetically engineered human stem cells. Now, in a subsequent study, they have demonstrated that these engineered cells can seek out and kill HIV-infected cells in a living organism.

In the previous project, the researchers took T cells from an HIV-infected individual, and isolated the T cell receptor within them – this is what allows the cells to identify and destroy cells infected with HIV. They proceeded to clone this receptor, then used it to genetically engineer human blood stem cells. These cells were then placed in human thymus tissue, that had itself been implanted in mice, where they proceeded to grow into HIV-specific T cells.

While the study indicated that it was possible to create genetically engineered HIV-fighting cells in the body, it didn’t test how those cells fared against HIV in a living organism. The more recent study, however, did.

This time around, similarly engineered HIV-specific T cells were introduced into infected “humanized mice” – lab mice that have been genetically engineered to carry human genes, cells or tissues. Two to six weeks later, tests were performed on the peripheral blood, plasma and organs of those mice. It was found that not only had the level of HIV in the bloodstream decreased, but the number of CD4 “helper” T cells had increased – CD4s are white blood cells that play a key role in fighting off infections, and they normally decrease in the event of HIV infection.

According to the scientists, these results indicated that the introduced T cells had developed and migrated to the organs, where they fought the HIV infection. They did note, however, that even in humanized mice, HIV may mutate slower than it does in humans. This means that multiple T cell receptors might have to be used, to account for the higher likelihood of the virus mutating in humans. To that end, the researchers have now begun creating receptors that target specific parts of the HIV virus.

“We believe that this study lays the groundwork for the potential use of this type of an approach in combating HIV infection in infected individuals, in hopes of eradicating the virus from the body,” said lead investigator Scott G. Kitchen.

A paper on the study was published yesterday in the journal PLoS Pathogens.

Source: UCLA

Published by Henry Sapiecha