Major component in turmeric enhance effect of chemotherapy drug in head and neck cancer

Thursday, 24 October 2013

Islamabad, Oct 25 (Newswire): Curcumin, the major component in the spice turmeric, when combined with the drug cisplatin enhances the chemotherapy's suppression of head and neck cancer cell growth, researchers with UCLA's Jonsson Cancer Center have found.

A naturally occurring spice widely used in South Asian and Middle Eastern cooking, Turmeric has long been known to have medicinal properties, attributed to its anti-inflammatory effects.

Previous studies have shown it can suppress the growth of certain cancers, said Dr. Marilene Wang, a professor of head and neck surgery, lead author of the study and a Jonsson Cancer Center researcher.

"Head and neck cancers, particularly cases diagnosed in a later stage, are terrible cancers that often require very radical surgeries and chemotherapy and radiation," Wang said.

"They often don't present until late, and the structures in the head and neck are so vital that our treatments often cause disfigurement and severe loss of function. So using non-toxic curcumin as a treatment was a very appealing idea."

The study, done in cells in Petri dishes and then in mouse models, appears in the October issue of the journal Molecular Cancer Therapeutics.

In India, women for years have been using turmeric for medicinal purposes, as an anti-aging agent rubbed into their ski, to treat cramps during menstruation, as a poultice on the skin to promote wound healing and as an additive in cosmetics, said scientist Eri Srivatsan, an adjunct professor of surgery and a Jonsson Cancer Center researcher who, along with Wang, has been studying curcumin and its anti-cancer properties for six years.

A 2005 study by Wang and Srivatsan first showed that curcumin suppressed the growth of head and neck cancer cells, first in cells and then in mouse models. In the animal studies, the curcumin was applied directly onto the tumors in paste form because it did not dissolve in saline, which would have allowed it to be injected.

In need of a better way to deliver the curcumin, the team collaborated with Dr. Kapil Mehta of M.D. Anderson Cancer Center and found that encapsulating the tumor in a liposome, an artificially prepared vehicle that enclosed the spice component within its membrane, made the treatment injectable.

The curcumin was injected into the tail vein of a mouse, where it circulated into the blood stream, slowing down and eventually stopping the cancer growth, a study in 2008 found.

"This was a very positive finding, developing an efficient way to deliver the treatment," Wang said. "Our study also showed that the curcumin was very well tolerated."

In this study, the team wanted to combine the curcumin with the chemotherapeutic drug cisplatin, which is very toxic at the doses needed to fight head and neck cancers, damaging kidneys, the ears and the bone marrow.

They hoped that if they added curcumin to the mix, they might be able to lower the cisplatin dose and cause less organ damage. Their finding, that the curcumin made the cisplatin work better, was very promising, Wang said.

"We knew that both the curcumin and the cisplatin, when given alone, had an effect against head and neck cancers," Wang said. "This finding that curcumin enhances cisplatin means that, in the future, we may be able to give this chemotherapy in lower doses."

The study noted that "the mechanisms of the two agents through different growth signaling pathways suggest potential for the clinical use of sub-therapeutic doses of cisplatin in combination with curcumin, which will allow effective suppression of tumor growth while minimizing the toxic side effects."

The study found that curcumin suppressed head and neck cancer growth by regulating cell cycling, Srivatsan said. It binds to an enzyme and prevents the enzyme IKK, an inhibitor of kappa B kinase, from activating a transcription factor called nuclear factor kappa B (NF?B), which promotes cancer growth. Cisplatin's suppressive action involves a different pathway through the tumor suppressor proteins p16 and p53, both proteins that again inhibit the activity of cancer growth promoter NF?B.

"We needed to know the mechanism to help us translate this from the lab into the clinic," Wang said. "That information will help us make better decisions on how to design therapies."

The next step in the clinical setting is to give patients oral curcumin prior to surgery and, after surgery, study the excised tumors to determine curcumin's effect on tumor markers, specifically whether there is reduced expression of markers such as growth promoting NF?B.

They also will be monitoring to determine if the curcumin results in any side effects. After that, the team would give curcumin to patients also getting chemotherapy and radiation to see if the tumor suppression found in the cells lines and mouse models can be replicated in humans.

Although turmeric is used in cooking, the amount of curcumin needed to produce a clinical response is much larger, about 500 milligrams. Expecting a positive effect through eating foods spiced with turmeric is not realistic, the researchers said.

Curcumin also has a suppressive effect on other cancers, Wang said, including breast, colon and pancreatic cancers. However, the mechanism of suppression in those cancers has not yet been uncovered. It also may be effective against Alzheimer's and aging, Wang said.

The study was funded by the VA Greater Los Angeles Surgical Education Research Center, UCLA Academic Senate, the National Institutes of Health and the Veterans Administration.
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Spinal cord stimulators tested as treatment for patients with migraine headaches

Wednesday, 23 October 2013

Islamabad, Oct 24 (Newswire): Researchers at Rush University Medical Center are testing a new treatment for migraine headaches: occipital nerve stimulation, a surgical procedure in which an implanted neurostimulator delivers electrical impulses to nerves under the skin at the base of the head at the back of the neck.

This therapy may help migraine sufferers who do not respond to other available therapies, or who cannot tolerate the side effects of existing medications.

"The purpose of the randomized, double-blinded study is to evaluate the safety and efficacy of occipital nerve stimulation as a treatment for refractory migraine headache," says Dr. Sandeep Amin, Rush study investigator and anesthesiologist who surgically implants the device in the two-visit operation.

Rush is recruiting patients through the Diamond Headache Clinic and is the only site in Illinois in the trial.

The study, known as PRISM (Precision Implantable Stimulator for Migraine), uses Boston Scientific's Precision neurostimulator with approximately 150 patients at up to 15 sites in the U.S. The implantable pulse generator will deliver electrical impulses to the occipital nerves located just under the skin at the base of the skull at the back of the neck.

The Precision device is the smallest rechargeable neurostimulator on the market today and is already approved by the FDA for spinal cord stimulation to treat chronic pain.

There are more than 28 million migraine sufferers in the U.S., and up to 10 percent of these patients may not respond to existing treatments.

"Occipital nerve stimulation has the potential to provide relief to the large population of migraine sufferers who currently have no other medical treatments available to them that bring them relief," said Amin. "If effective, the implantable neurostimulator would provide a new treatment option to free these patients from their long-standing headache pain."

The smallest rechargeable neurostimulator available, the Precision device has been used in the treatment of more than 6,000 patients suffering from chronic pain, according to Boston Scientific.

The Precision neurostimulator is currently FDA approved for spinal cord to treat chronic pain by precisely delivering tiny electrical signals to the spinal cord that mask the perception of pain. Spinal cord stimulation is prescribed for patients with chronic pain in the limbs, trunk and back.

Migraine sufferers are monitored and complete a month-long pain diary as the first part of the study. Patients then undergo a two-part operation in which thin electrode leads are placed under the skin at the back of the neck.

A week later, the patient returns for the 45 minute procedure in which the neurostimulator is placed on one side in the lowest part of the back, and the leads are connected and the device activated. Patients then return to the neurologist for monitoring of their headaches.

During the first 3 months after the Precision neurostimulator is implanted, two different stimulation settings will be tried in different groups of patients. One group of patients is programmed to settings more likely to show a response, while the control group of patients is programmed to settings rather unlikely to be effective.

After the first three months, the control group of patients will have their devices programmed to the stimulation settings more likely to show a response.
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First implanted device to treat balance disorder developed

Islamabad, Oct 24 (Newswire): A University of Washington Medical Center patient on Thursday, Oct. 21, became the world's first recipient of a device that aims to quell the disabling vertigo associated with Meniere's disease.

The UW Medicine clinicians who developed the implantable device hope that success in a 10-person surgical trial of Meniere's patients will lead to exploration of its usefulness against other common balance disorders that torment millions of people worldwide.

The device being tested -- a cochlear implant and processor with re-engineered software and electrode arrays -- represents four-plus years of work by Drs. Jay Rubinstein and James Phillips of UW's Department of Otolaryngology-Head and Neck Surgery. They worked with Drs. Steven Bierer, Albert Fuchs, Chris Kaneko, Leo Ling and Kaibao Nie, UW specialists in signal processing, brainstem physiology and vestibular neural coding.

"What we're proposing here is a potentially safer and more effective therapy than exists now," said Rubinstein, an ear surgeon and auditory scientist who has earned a doctoral degree in bioengineering and who holds multiple U.S. patents.

In the United States, Meniere's affects less than one percent of the population. The disease occurs mostly in people between ages 30 and 50, but can strike anyone. Patients more often experience the condition in one ear; about 30 percent of cases are bilateral.

The disease affects hearing and balance with varying intensity and frequency but can be extremely debilitating. Its episodic attacks are thought to stem from the rupture of an inner-ear membrane. Endolymphatic fluid leaks out of the vestibular system, causing havoc to the brain's perception of balance.

To stave off nausea, afflicted people must lie still, typically for several hours and sometimes up to half a day while the membrane self-repairs and equilibrium is restored, said Phillips, a UW research associate professor and director of the UW Dizziness and Balance Center. Because the attacks come with scant warning, a Meniere's diagnosis can cause people to change careers and curb their lifestyles.

Many patients respond to first-line treatments of medication and changes to diet and activity. When those therapies fail to reduce the rate of attacks, surgery is often an effective option but it typically is ablative (destructive) in nature. In essence, the patient sacrifices function in the affected ear to halt the vertigo -- akin to a pilot who shuts down an erratic engine during flight. Forever after, the person's balance and, often, hearing are based on one ear's function.

With their device, Phillips and Rubinstein aim to restore the patient's balance during attacks while leaving natural hearing and residual balance function intact.

A patient wears a processor behind the affected ear and activates it as an attack starts. The processor wirelessly signals the device, which is implanted almost directly underneath in a small well created in the temporal bone. The device in turn transmits electrical impulses through three electrodes inserted into the canals of the inner ear's bony labyrinth.

"It's an override," Phillips said. "It doesn't change what's happening in the ear, but it eliminates the symptoms while replacing the function of that ear until it recovers."

The specific placement of the electrodes in the bony labyrinth is determined by neuronal signal testing at the time of implant. The superior semicircular canal, lateral semicircular canal and posterior semicircular canal each receive one electrode array.

A National Institutes of Health grant funded the development of the device and its initial testing at the Washington National Primate Research Center. The promising results from those tests led the U.S. Food and Drug Administration, in June, to approve the device and the proposed surgical implantation procedure. Shortly thereafter, the limited surgical trial in humans won approval from the Western Institutional Review Board, an independent body charged with protecting the safety of research subjects.

By basing their invention on cochlear implants whose design and surgical implantation were already FDA-approved, Phillips and Rubinstein leapfrogged scientists at other institutions who had begun years earlier but chosen to develop novel prototypes.

"If you started from scratch, in a circumstance like this where no one has ever treated a vestibular disorder with a device, it probably would take 10 years to develop such a device," Rubinstein said.

The device epitomizes the translational advancements pursued at UW's academic medical centers, he said. He credited the team's skills and its access to the primate center, whose labs facilitated the quick turnaround of results that helped win the FDA's support.

A successful human trial could lead the implant to become the first-choice surgical intervention for Meniere's patients, Phillips said, and spark collaboration with other researchers who are studying more widespread balance disorders.

The first patient will be a 56-year-old man from Yakima, Wash. He has unilateral Meniere's disease and has been a patient of Rubinstein's for about two years.

See a related video at UW Medicine's YouTube site. Drs. Rubinstein and Phillips discuss the device: http://www.youtube.com/watch?v=iu047vTckvA

Cochlear Ltd. of Lane Cove, Australia, will manufacture the device. Cochlear is a medical equipment company and longtime maker of devices for hearing-impaired people.
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Younger brains are easier to rewire

Islamabad, Oct 24 (Newswire): A new paper from MIT neuroscientists, in collaboration with Alvaro Pascual-Leone at Beth Israel Deaconess Medical Center, offers evidence that it is easier to rewire the brain early in life.

The researchers found that a small part of the brain's visual cortex that processes motion became reorganized only in the brains of subjects who had been born blind, not those who became blind later in life.

The new findings, described in the journal Current Biology, shed light on how the brain wires itself during the first few years of life, and could help scientists understand how to optimize the brain's ability to be rewired later in life.

That could become increasingly important as medical advances make it possible for congenitally blind people to have their sight restored, said MIT postdoctoral associate Marina Bedny, lead author of the paper.

In the 1950s and '60s, scientists began to think that certain brain functions develop normally only if an individual is exposed to relevant information, such as language or visual information, within a specific time period early in life. After that, they theorized, the brain loses the ability to change in response to new input.

Animal studies supported this theory. For example, cats blindfolded during the first months of life are unable to see normally after the blindfolds are removed. Similar periods of blindfolding in adulthood have no effect on vision.

However, there have been indications in recent years that there is more wiggle room than previously thought, said Bedny, who works in the laboratory of MIT assistant professor Rebecca Saxe, also an author of the Current Biology paper. Many neuroscientists now support the idea of a period early in life after which it is difficult, but not impossible, to rewire the brain.

Bedny, Saxe and their colleagues wanted to determine if a part of the brain known as the middle temporal complex (MT/MST) can be rewired at any time or only early in life. They chose to study MT/MST in part because it is one of the most studied visual areas. In sighted people, the MT region is specialized for motion vision.

In the few rare cases where patients have lost MT function in both hemispheres of the brain, they were unable to sense motion in a visual scene. For example, if someone poured water into a glass, they would see only a standing, frozen stream of water.

Previous studies have shown that in blind people, MT is taken over by sound processing, but those studies didn't distinguish between people who became blind early and late in life.

In the new MIT study, the researchers studied three groups of subjects -- sighted, congenitally blind, and those who became blind later in life (age nine or older). Using functional magnetic resonance imaging (fMRI), they tested whether MT in these subjects responded to moving sounds -- for example, approaching footsteps.

The results were clear, said Bedny. MT reacted to moving sounds in congenitally blind people, but not in sighted people or people who became blind at a later age.

This suggests that in late-blind individuals, the visual input they received in early years allowed the MT complex to develop its typical visual function, and it couldn't be remade to process sound after the person lost sight. Congenitally blind people never received any visual input, so the region was taken over by auditory input after birth.

"We need to think of early life as a window of opportunity to shape how the brain works," said Bedny. "That's not to say that later experience can't alter things, but it's easier to get organized early on."

Bedny believes that by better understanding how the brain is wired early in life, scientists may be able to learn how to rewire it later in life. There are now very few cases of sight restoration, but if it becomes more common, scientists will need to figure out how to retrain the patient's brain so it can process the new visual input.

"The unresolved question is whether the brain can relearn, and how that learning differs in an adult brain versus a child's brain," said Bedny.

Bedny hopes to study the behavioral consequences of the MT switch in future studies. Those would include whether blind people have an advantage over sighted people in auditory motion processing, and if they have a disadvantage if sight is restored.
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