Natural hydrogel may boost spinal cord healing

Washington, Sep 18 (ANI): A jab of biomaterial gel into a spinal cord injury site may significantly improve healing, according to researchers at the Barrow Neurological Institute at St. Joseph’s Hospital and Medical Center.

Dr. Mark Preul and Dr. Alyssa Panitch have found in a study that injection of an engineered hydrogel made up mainly of hyaluronic acid (a naturally-occurring body substance) into the spinal cord injury site decreases scarring, and promotes a realignment of the spinal cord fibres around the injury site.

The hyaluronic acid, which forms a scaffold-like configuration may help to structurally stabilize the spinal cord injury site.

The researchers traced cells in the brain stem after injury, and found much higher levels in the hydrogel treated animals as compared to animals that did not receive the treatment, and approached nearly normal levels.

Treated animals had higher functional scores than their non-treated counterparts.

“Spinal cord injury is devastating to civilian and military populations – especially to the young. There has been little progress toward paradigms of regeneration and few results that show real, sustained functional recovery. We’ve been so pre-occupied with regeneration, but that is a highly complicated and difficult to define goal. This project is a synergy of neurosurgeons and bioengineers that attempts repair of the SCI lesion cavity using a tissue-engineering biomaterials approach,” says Preul.

He added that the team aimed at finding ways to structurally allow the body to better heal itself.

“In this project we did not add anything to the hyaluronic acid. It may be that adding growth factors or cells into the gel matrix may allow even better results,” he said.

Preul said that the results show “we may be on a practical path that can give hope to the many people who suffer this sort of injury.”

The work was presented at the Annual Meeting of the American Association of Neurological Surgeons in San Diego where it won the Synthes Prize for Spine Research. (ANI)

Three genes linked to Lou Gehrig’s disease identified

Washington, Sep 10 (ANI): Researchers at Michigan Technological University have identified three genes that play a major role in the most common type of amyotrophic lateral sclerosis (ALS), generally known as Lou Gehrig’s disease.

The team of mathematicians, led by Shuanglin Zhang, isolated the genes from the many thousands scattered throughout human DNA.

Zhang noted that the discovery does not mean an end to ALS, but it could provide scientists with valuable clues as they search for a cure.

“I felt very urgent to find the genes for ALS,” Zhang said.

“This is very nice work. It’s very challenging to map genes for complex diseases, and while many statistical methods have been developed, most don’t work well in practice. Zhang’s group has developed a method to detect genes and gene-gene interaction in complex diseases and provided evidence that it works,” said Xiaofeng Zhu, an associate professor of epidemiology at Case Western Reserve University’s School of Medicine.

“Their findings will need to be confirmed by other researchers, but I think this will be very useful for the investigators who are trying to find genes underlying complex diseases such as ALS,” said Zhu.

According to the ALS Association, only about 10 percent of patients have familial ALS, a directly inherited form of the usually fatal neuromuscular disorder, while the remaining 90 percent are diagnosed with the sporadic form of the disease.

While everyone has the three genes in question, but in people with sporadic ALS, they differ from those in people who don’t have ALS.

The mathematicians were not surprised when they tracked down the location of the genes.

“Everybody has 23 chromosomes, and the three genes on chromosomes 2, 4, and 10 interact. If you have this combination of the three genes, you are at high risk of developing the disease. It’s really exciting, especially because my husband has sporadic ALS. Maybe they can find a cure by blocking the genes,” explained Zhang’s wife Qiuying Sha.

ALS destroys the nerves in the brain and spinal cord that control voluntary movement, eventually leading to paralysis.

Zhang’s team used a new statistical method to analyse the genetic codes of 547 individuals, 276 with sporadic ALS and 271 without.

The method, a two-locus interaction analysis approach, allows the researchers to identify multiple genes associated with a complex illness.

The data set they analyzed was provided by National Institute of Neurological Disorders and Stroke (NINDS) Human Genetics Resource Center at the Coriell Institute, a publicly funded “bank” or repository for human cells, DNA samples, clinical data, and other information that aims to accelerate research on the genetics of nervous system disorders.

The study has been published in the open access journal BMC Medical Genetics. (ANI)

Smoking may lead to brain damage in multiple sclerosis patients

Washington, Aug 18 (ANI): Cigarette smoking can cause brain damage in patients with multiple sclerosis (MS), according to a new study.

Scientists at the University at Buffalo have shown that MS patients who smoked for a little as six months during their lifetime had more destruction of brain tissue and more brain atrophy than the patients who never smoked.

“Cigarette smoking is one of the most compelling environmental risk factors linked to the development and worsening of MS,” said Dr Robert Zivadinov, UB professor of neurology, director of the Buffalo Neuroimaging Analysis Centre (BNAC) where the research was conducted and first author on the study.

“The biological basis of the potential link between smoking and MS has not yet been fully elucidated.

“In addition to nicotine, cigarette smoke contains hundreds of potentially toxic components, including tar, carbon monoxide and polycyclic aromatic hydrocarbons.

“In MS patients, smoking was associated with higher increased lesion burden and greater brain atrophy. Our results indicate that a wide range of quantitative brain MRI markers are affected by smoking in MS patients,” he added.

The study involved 368 patients from the Baird Multiple Sclerosis Center of the Jacobs Neurological Institute (JNI), where 128 had a history of smoking: 96 were active smokers who had smoked more than 10 cigarettes-per-day in the three months prior to the study start and 32 were former smokers who had smoked cumulatively for at least six months sometime in the past.

The remaining 240 participants were lifelong nonsmokers.

They found that that smokers with MS had a greater breakdown of the blood-brain barrier.

They had nearly 17 percent more brain lesions – patches of inflammation in the sheath surrounding the nerve fibres that impair their function – than nonsmokers with MS, and also had less brain volume.

Smoking also was associated with increased physical disability.

“The findings underscore the detrimental effect of smoking, providing a link between smoking and a more severe brain injury in MS patients,” said Dr Bianca Weinstock-Guttman, director of the Baird MS Center, UB associate professor of neurology and a principal co-author on the study.

The study appears in Neurology(r), the medical journal of the American Academy of Neurology. (ANI)

Gene linked to narcolepsy identified

London, May 4 (ANI): Researchers have identified a gene linked to narcolepsy, a disorder that causes disabling daytime sleepiness, sleep attacks, irresistible bouts of sleep and disturbed sleep at night.

The gene is known for its role in the immune system, which strongly suggests that autoimmunity, in which the immune system turns against the body’s own tissues, plays an important role in the disorder.

The research team has found a gene called HLA-DQB1*0602.

This is one of the genes that encodes HLA proteins, which mark the surface of the body’s cells and help the immune system identify foreign proteins.

“The link between narcolepsy and autoimmunity was proposed decades ago, but efforts to verify it have failed repeatedly. Current findings leave little doubt that autoimmunity plays a role,” Nature quoted Dr Merrill Mitler, a program director with the National Institute of Neurological Disorders and Stroke (NINDS) as saying.

During the study, the researchers focused on narcolepsy with cataplexy – a sudden loss of muscle tone that can cause a person to collapse, with or without falling asleep.

This is due to the death of a small group of brain cells that normally regulate the sleep-wake cycle by releasing chemicals called hypocretins.

Some researchers believe that the HLA variants found in people with narcolepsy-cataplexy predispose them to an autoimmune reaction that destroys their hypocretin-producing cells.

In addition, people with narcolepsy-cataplexy are also more likely to have unique variants of the TCRA gene, which encodes a receptor protein on the surface of T cells.

The findings revealed that narcolepsy-cataplexy is linked to autoimmunity and involves T-cells. The research could lead to new approaches to prevention and treatment. One possibility may be preventing the disorder by stopping the effects of the autoimmune process.

“If we can define the changes in the T cell receptor associated with narcolepsy-cataplexy, we might be able to develop drugs that block the protein’s abnormal activity and prevent the onset of the disorder,” said Dr Emmanuel Mignot, director of the Center for Narcolepsy at Stanford University School of Medicine in Palo Alto, Calif., and a Howard Hughes Medical Institute investigator.

In people with the HLA variants that predispose to narcolepsy-cataplexy, there is about a 20-fold higher frequency of the disorder if variants in the TCRA gene are present.

The study appears in Nature Genetics. (ANI)

ADHD drug may help individuals with aphasia regain language abilities

Washington, Feb 18 (ANI): A medication commonly prescribed for attention deficit hyperactivity disorder (ADHD) can also treat aphasia – a condition where a person loses his ability to recall and produce common words.

Aphasia is caused by lesions to the language centers of the brain. These lesions are often due to stroke or brain injury, but can also be the result of a brain tumour or progressive disease such as Parkinson’s or Alzheimer’s.

Types of aphasia can range from a patient having difficulty finding and producing a word to a patient having no ability at all to speak or understand language.

While most aphasia patients benefit from behavioral therapy to regain their language skills, a new area of treatment is opening up which looks at certain drugs to help augment the therapy.

“The standard of care for patients with aphasia has always been and will always be speech/language therapy, but a new area is opening up that looks at what drugs can be used in combination with therapy to enhance recovery from brain damage and help the brain repair itself,” said Gerry Stefanatos, D.Phil., an associate professor of communication sciences and disorders in the College of Health Professions.

“We’re looking at the mechanism of how this combination works – it’s underlying effect on patients with aphasia,” Stefanatos said.

Stefanatos found that dextroamphetamine (D-AMPH), a drug commonly used to treat ADHD can help process speech in the brain.

The blue trace (above) represents brain electrical activity in response to speech during therapy while on the medication.

Stefanatos’ study looked at the use of D-AMPH in ten aphasia patients. All were also given a placebo for comparison purposes. In each condition, participants were asked to make decisions about different types of speech sounds (vowels, consonant-vowels) and complex tones. Their brain’s electrical response to each was recorded via an electroencephalogram (EEG).

Those who took the D-AMPH had a strong reaction to the sounds – even to consonant-vowel sounds, which are more often difficult for individuals with aphasia to process.

“This tells us that D-AMPH may help the left hemisphere of the brain regain the ability to perform its functions. Understanding why the drug is having this effect allows us to start to think about how to tailor treatments to make them more effective or explore alternative drugs or drug combinations,” said Stefanatos.he research has been presented at the International Neurological Society this month. (ANI)