New advance in gene therapy for blindness

Health Feb. 12, 2012 - 05:10AM JST

WASHINGTON — U.S. scientists have reported a new advance in using gene therapy to restore eyesight in people with a rare, inherited form of blindness.

The therapy, which had been previously tried in just one eye of 12 people, worked well when injected into the other eye of three of the patients, offering a sign that the treatment is safe, effective and will not be rejected by the body.

“Our concern was that the first treatment might cause a vaccine-like immune response that could prime the individual’s immune system to react against a repeat exposure,” said lead author Jean Bennett, professor of ophthalmology at the University of Pennsylvania.

Despite the risks, three adult patients from the initial study—whose results were published in 2009 showing that some level of vision had been restored in all of them and six were no longer legally blind—agreed to try the therapy in their untreated eye.

The trio were all better able to see in dim light afterward, and two were able to navigate obstacles in low-light situations. There were no reports of ill side-effects.

The study appears in the journal Science Translational Medicine.

“Patients have told us how their lives have changed since receiving gene therapy,” said Bennett. “They are able to walk around at night, go shopping for groceries and recognize people’s faces—all things they couldn’t do before.”

The revolutionary treatment targets a disease of light-catching retinal cells called Leber’s congenital amaurosis, or LCA.

Caused by flaws in any one of around 13 key genes, LCA triggers severe loss of vision and abnormal eye movements in early infancy, usually leading to total blindness in the twenties or thirties.

Bennett and colleagues tested a way of tackling the disease by inserting a corrective gene in a disabled cold virus.

The modified virus was injected into the eyeball, and infected the diseased cells—in effect, acting like a Trojan horse to deliver the right DNA to the retina.

Twelve patients aged eight to 44 years were recruited in the small, experimental study, and were given the treatment in the eye that had the worst vision.

None of the patients recovered normal sight, but all of them had an at-least 100-fold increase in so-called pupillary light response, meaning the constriction of the pupil when exposed to light.

Six of the 12 recovered sufficient sight that meant they may no longer be classified as legally blind.

The best results were among four children aged eight, nine, 10 and 11.

Their first study was published by The Lancet in 2009.

Gene medicine is one of the most alluring areas of biotechnology, offering the theoretical promise of blocking or reversing inherited disease.

But this new frontier has also been hit by occasional setbacks, notably an unexpected or uncontrollable response from the immune system.

The pioneering treatment for LCA, though, has so far had no side effects and its benefits have remained unchanged years later, say the researchers.

More research is needed before the therapy can be confirmed safe, but the latest findings bode well for trying it in more of the initial subjects, particularly the youngest ones whose retinas have not degenerated as much as those of the adults.

© 2012 AFP

http://www.japantoday.com/category/health/view/new-advance-in-gene-therapy-for-blindness

U.S. begins stem cell trial for hearing loss

Health Feb. 13, 2012 - 10:00AM JST

WASHINGTON — U.S. researchers have begun a groundbreaking trial to test the potential of umbilical cord blood transplants, a kind of stem cell therapy, to treat and possibly reverse hearing loss in infants.

The phase I trial follows promising studies on mice showing that such transplants were able to rebuild the structures of the inner ear, and some anecdotal evidence from humans, sparking hope of a cure for some forms of deafness.

One of those people is two-year-old Finn McGrath, who suffered brain damage after being deprived of oxygen during a prolonged and complicated delivery, according to his mother, Laura.

“His doctors told us he was at high risk for cerebral palsy, vision issues, hearing problems and mental retardation,” she said in an interview with AFP.

Finn’s early days were an all-out struggle to survive, so for his parents, learning that he had failed his hearing tests and had damaged hair cells—the sensory receptors in the inner ear that pick up sounds—was almost an afterthought.

He had organ failure, breathing problems, and his cerebral palsy left him unable to roll, crawl or walk, hold his head up, talk or eat.

As his parents searched for ways to help him, they came upon stories online that told of studies using cord blood to help children with cerebral palsy and other disorders.

Prior to his birth, the McGraths had arranged to privately bank his umbilical cord blood, a procedure that costs around $2,000 plus storage fees, and remains controversial among pediatricians.

Private companies such as the Cord Blood Registry, which is funding the Texas study on hearing loss, urge expecting parents to bank their umbilical cord blood and reserve it for personal use as a way to protect their family.

That advice runs counter to the guidelines issued by the American Academy of Pediatrics in 2007, which calls such claims “unsubstantiated” and says banking for personal or family use “should be discouraged” but is “encouraged” if it is to be stored in a bank for public use.

Since Finn’s parents had already banked his, they enrolled him in cord blood trial for cerebral palsy in North Carolina and he received his first transplant in November 2009 when he was about seven weeks old.

A second transfusion followed and by May, his parents began to notice a change.

Nighttime noises, like an alarm on his food pump or the sound of ripping medical tape, would suddenly startle him awake, his mother recalled.

“He started vocalizing sounds and we could tell that he was anticipating things that we would say. Like, if he had heard a story a number of times or a song, he would smile like he recognized the song or the story.”

Finn had a third infusion in September 2010, when he was one year old. Four months later, an otoacoustic emissions test (OAE), which plays a sound and picks up vibrations in the cochlea and hair cells, came back normal.

The early hearing tests that showed hearing loss were not exactly the same as the later tests that came back normal, so McGrath is cautious about comparing them directly, but she believes the cord blood transfusions may have helped.

“All I can tell you is anecdotally he was not able to hear for probably the first three or four months of his life, and then when he was about six to eight months old, he started hearing.”

The hearing trial in Texas aims to take a first step in testing the safety, and later the efficacy, of transfusing cord blood in children age six weeks to 18 months who have sustained post-birth sensorineural hearing loss.

Some reasons that children lose their hearing at or after birth may include oxygen deprivation, head injury, infection, strong doses of antibiotics or loud noises.

Sensorineural hearing loss affects approximately six per 1,000 children, and there is no available medical treatment. Hearing aids or cochlear implants are typically offered to boost the ability of the damaged tissues.

“Stem cell therapy may potentially repair the damaged structures of the inner ear and restore normal hearing,” lead investigator Samer Fakhri told AFP.

“We are at the initial stages of this process and the results are looking promising,” Fakhri added.
Research using stem cells in cord blood, known as hematopoietic cells, is already under way on some types of brain injury, cerebral palsy, juvenile diabetes, kidney and lung disease, he said.

The new study at Memorial Hermann-Texas Medical Center is being funded by the Cord Blood Registry, and those eligible must have already banked their own umbilical cord blood with CBR.

But to Stephen Epstein, an otolaryngologist in Maryland, that does not pose a conflict of interest, because separate medical institutions in Texas and Georgia are conducting the Food and Drug Administration-approved research.

“If both of them can reproduce the same results then I would say it has some validity to it,” said Epstein, who is not involved in the study.

“This is certainly a welcome, acceptable experiment, but it should be looked at with caution and time will tell.”

One patient is already enrolled and the study, which runs for one year, has room for nine more.

While Finn McGrath still faces many challenges due to his cerebral palsy, his mother is grateful for the things he can do.

“I don’t know how much worse off he would have been without the stem cell transfusion,” McGrath said, pointing to his normal cognition, lack of seizures, good hearing and vision.

“We remain hopeful that he will continue to improve.”

© 2012 AFP

http://www.japantoday.com/category/health/view/u-s-begins-stem-cell-trial-for-hearing-loss

Brain stimulation may boost memory: study

Health Feb. 15, 2012 - 07:00AM JST

WASHINGTON — California scientists may have found a way to stimulate a part of the brain so that it forms memories more easily.

Someday, the process might be used to make a neuroprosthetic device, or thinking cap, that people could turn on when they need to remember new information, or it may even help people with dementia restore their memories.

But those possibilities, while intriguing, are far off in the future, said researchers at the University of California Los Angeles whose study on seven epilepsy patients appeared in the New England Journal of Medicine.

“Losing our ability to remember recent events and form new memories is one of the most dreaded afflictions of the human condition,” said senior author Itzhak Fried, professor of neurosurgery at the David Geffen School of Medicine at UCLA.

“Our preliminary results provide evidence supporting a possible mechanism for enhancing memory, particularly as people age or suffer from early dementia,” he said.

“At the same time, we studied a small sample of patients, so our results should be interpreted with caution.”

Using patients who already had electrodes implanted into their brains to track the origin of epileptic seizures, the researchers studied the effect of nerve stimulation in a part of the brain called the entorhinal cortex.

The entorhinal cortex is considered the doorway to the hippocampus, the part of the brain where memories are formed and stored.

“The entorhinal cortex is the golden gate to the brain’s memory mainframe,” said Fried.

“Every visual and sensory experience that we eventually commit to memory funnels through that doorway to the hippocampus.”

Patients played a video game in which they were driving a taxi to deliver riders to particular places in town, and they showed improved recall when the entorhinal cortex was stimulated.

“When we stimulated the nerve fibers in the patients’ entorhinal cortex during learning, they later recognized landmarks and navigated the routes more quickly,” said Fried.

“They even learned to take shortcuts, reflecting improved spatial memory.”

More research is needed to determine if deep-brain stimulation could boost other forms of recall such as verbal and autobiographical memories.

The study was funded by grants from the National Institute of Neurological Disorders and Stroke and the Dana Foundation which supports brain research.

© 2012 AFP

http://www.japantoday.com/category/health/view/brain-stimulation-may-boost-memory-study

Fasting Weakens Cancer ?

Study on mice shows fasting weakens cancer

Health Feb. 18, 2012 - 05:08AM JST

WASHINGTON — Early research on mice with cancer shows that fasting may weaken tumors and help chemotherapy work better, scientists say.

While it remains unknown if the same approach could work in humans, or if it would even be safe, researchers said the findings suggest a promising new route of study for improving response to cancer treatment.

In the mice experiments, “the combination of fasting cycles plus chemotherapy was either more or much more effective than chemo alone,” said senior author Valter Longo, professor of gerontology and biological sciences at the University of Southern California (USC).

Longo and colleagues previously published findings in 2008 that showed how fasting protected normal cells against chemotherapy in a study that focused on one type of cancer and a single chemo drug.

The latest study expands on that research to show that fasting makes cancer cells more vulnerable, and spanned several different types of cancer in mice.

Types of cancers studied included breast cancer, melanoma, glioma and human neuroblastoma.
All cancers studied showed that fasting combined with chemotherapy improved survival, slowed the growth of tumors and/or limited their spread.

The study appears in the journal Science Translational Medicine.

“We don’t know whether in humans it’s effective,” Longo said, adding that for now fasting should be “off-limits” to cancer patients, although they should feel they can ask their doctors about the possibility.

In 2010, a small study of 10 human cancer patients who tried fasting cycles with their drug treatment showed that they perceived fewer side effects from chemo, according to self-reported data. The study was published in the journal Aging.

The results of a phase 1 trial assessing the safety of fasting two days before and one day after chemotherapy in patients with breast, urinary tract and ovarian cancer, conducted at the USC, have been submitted for presentation at the annual meeting of the American Society of Cancer Oncologists later this year.

“A way to beat cancer cells may not be to try to find drugs that kill them specifically but to confuse them by generating extreme environments, such as fasting that only normal cells can quickly respond to,” Longo said.

© 2012 AFP

http://www.japantoday.com/category/health/view/study-on-mice-shows-fasting-weakens-cancer

Aspirin may inhibit spread of cancer

Health Feb. 16, 2012 - 06:13AM JST

SYDNEY —

Many doctors recommend regular use of

aspirin to lower the risk of heart attackAFP

Aspirin and other household drugs may inhibit the spread of cancer because they help shut down the chemical “highways” which feed tumors, Australian researchers say.

Scientists at Melbourne’s Peter MacCallum Cancer Centre said they have made a biological breakthrough helping explain how lymphatic vessels—key to the transmission of tumors throughout the body—respond to cancer.

“We’ve shown that molecules like the aspirin… could effectively work by reducing the dilation of these major vessels and thereby reducing the capacity of tumors to spread to distant sites,” researcher Steven Stacker said.

Doctors have long suspected that non-steroidal anti-inflammatory drugs such as aspirin may help inhibit the spread of cancer but they have been unable to pinpoint exactly how this is done.

By studying cells in lymphatic vessels, the researchers found that a particular gene changed its expression in cancers which spread, but not when the cancer did not spread.

The results published in Cancer Cell journal reveal that the gene is a link between a tumor’s growth and the cellular pathway which can cause inflammation and dilation of vessels throughout the body.

Once these lymphatic vessels widen, the capacity for them to act as “supply lines” to tumors and become more effective conduits for the cancer to spread is increased.

But aspirin acts to shut down the dilation of the vessels.

“So it seems like we have found a pivotal junction point in a biochemical sense between all these different contributors,” Stacker said.

The discovery could lead to new and improved drugs which could help contain many solid tumors, including breast and prostate cancer, as well as potentially provide an “early warning system” before a tumor begins to spread.

Last year, a study published in medical journal The Lancet found that rates of cancer of the colon, prostate, lung, brain and throat were all reduced by daily aspirin use.

Many doctors recommend regular use of aspirin to lower the risk of heart attack, clot-related strokes and other blood flow problems. A downside of extended daily use is the risk of stomach problems.

© 2012 AFP

http://www.japantoday.com/category/health/view/aspirin-may-inhibit-spread-of-cancer

Antibiotics don't help sinusitis: researchers

Health Feb. 21, 2012 - 06:22AM JST

WASHINGTON —

Antibiotics provide little help to people with sinus infections, according to a study which suggested doctors are prescribing the drugs too often.

The study appearing in the Journal of the American Medical Association found that using the common antibiotic amoxicillin for patients with acute uncomplicated rhinosinusitis “did not result in a significant difference in symptoms compared to patients who received placebo.”

“Patients don’t get better faster or have fewer symptoms when they get antibiotics,” said Jay Piccirillo of Washington University in St Louis, Missouri, the study’s senior author.

“Our results show that antibiotics aren’t necessary for a basic sinus infection—most people get better on their own.”

Antibiotics are commonly used to treat the condition, which involves inflammation of the nasal cavity and sinuses, even though there is limited evidence supporting their effectiveness, the researchers said, warning about the dangers of overuse of antibiotics.

The study authors said one in five antibiotics prescribed for adults in the United States is for sinus infections, and that many people come to expect this treatment.

“We feel antibiotics are overused in the primary-care setting,” says Jane Garbutt, a professor of medicine and the paper’s first author.

“There is a movement afoot, led by the Centers for Disease Control and Prevention, to try to improve the judicious use of antibiotics. We hope this study provides scientific evidence that doctors can use with patients to explain that an antibiotic is not likely to help an acute sinus infection.”

The research, one of many highlighting the problems of resistance to antibiotics, said such drugs should be reserved “for patients with moderately severe or severe symptoms.”

Instead of giving antibiotics, such as the amoxicillin used in this study, the researchers suggest treating symptoms, such as pain, cough and congestion, along with watchful waiting to see whether further treatment is necessary.

The study included 166 adults with moderate, severe or very severe symptoms such as sinuses and nasal discharge that lasted between seven and 28 days.

© 2012 AFP

http://www.japantoday.com/category/health/view/antibiotics-dont-help-sinusitis-researchers

Tai chi improves balance in Parkinson's patients

Health Feb. 14, 2012 - 07:09AM JST

WASHINGTON —

People with Parkinson’s disease who practiced the Chinese martial art tai chi for six months showed better balance than counterparts who did other forms of exercise, a U.S. study says.

A total of 195 people took part in the randomized study in four different cities in the western state of Oregon, according to the results published in the New England Journal of Medicine.

Subjects were assigned to twice weekly sessions of 60 minutes each in either tai chi, resistance-training or stretching.

Those who did tai chi outperformed the stretching and resistance-training groups in tests of balance and length of stride when walking.

The tai chi group also showed experienced fewer falls than the stretchers, and just as many falls as the resistance-trainers.

“These results are clinically significant because they suggest that tai chi, a low-to-moderate impact exercise, may be used, as an add-on to current physical therapies, to address some of the key clinical problems in Parkinson’s disease,” said lead author Fuzhong Li of the Oregon Research Institute.

“The improvements in the balance and gait measures that we demonstrated highlight the potential of tai chi-based movements in rehabilitating patients with these types of problems.”

Tai chi entails regular practice of deep breathing and relaxation techniques, combined with slow and gentle movements.

It is based on tenets in Confucian and Buddhist philosophies that there are two opposing life forces, yin and yang, which govern health.

Ill health results from an imbalance in these forces, but it can be corrected by tai chi, according to these beliefs.

Parkinson’s is a progressive motor-system disorder which usually affects people over the age of 50, although it can strike earlier, often causing severe symptoms including body trembling, stiffness and loss of balance.

© 2012 AFP

http://www.japantoday.com/category/health/view/tai-chi-improves-balance-in-parkinsons-patients