Posts tagged medicine
Articles and news from the latest research reports.
A third of a million adults in the UK are to be invited to take part in the world’s biggest study of cognitive function.
FDA approves first-of-a-kind sleep apnea implant
Sleep-deprived Americans have a new option to address hard-to-treat nighttime breathing problems: a first-of-kind device that keeps airways open by zapping them with an electrical current.
The Food and Drug Administration approved the pacemaker-like device from Inspire Medical Systems for sleep apnea patients who have trouble with the current standard of care: machines that blow air through a bedtime mask.
New Version of Old MS Drug Performs Well in Clinical Trial
Tests of a new long-acting version of one of the oldest multiple sclerosis (MS) drugs on the market show it worked significantly better than placebo in reducing the number of patient relapses and developments of new or active lesions, researchers report. Most important, they add, the updated version was effective even though injections were given every two weeks instead of every other day, and it appears that fewer patients develop resistance to it.
The industry-funded, international clinical trial led by a Johns Hopkins scientist found that pegylated interferon beta worked far better than placebo for people with the most common form of MS. The beneficial effects seen in this study were comparable to what was found in previous studies in which the standard formulation of interferon beta (which must be taken more frequently) was compared to placebo.
In a report on the trial, published May 1 in The Lancet Neurology, the researchers say they also found that while roughly 20 percent of MS patients typically develop antibodies against the drug that ultimately neutralize its effects, fewer than 1 percent in the new study did, suggesting far more patients could benefit from the new formulation.
“While this isn’t a brand new blockbuster drug, I do think it will improve compliance and tolerability and therefore positively impact the quality of life of people with MS who take interferon beta,” says study leader Peter A. Calabresi, M.D., a professor of neurology at the Johns Hopkins University School of Medicine. “If it gets FDA approval, this new formulation would allow patients to get the same effect, but instead of the burden of injecting themselves every other day, they only have to do it twice a month. For an MS patient, that’s a huge advance.”
“The data are very, very clear,” Calabresi adds. “We can make things easier for our patients without dangerous side effects just by tweaking what we know to be a safe, 20-year-old drug.”
MS is considered an autoimmune disorder, caused when the immune system wrongly attacks a person’s own tissues; in this case, it’s the fatty protein myelin sheath that insulates nerves that send electrical signals to control movement, speech and other functions. The immune system primes so-called T cells in the body’s lymph nodes, preparing them to seek out and destroy myelin, a process that can lead to debilitating symptoms such as blurred vision, weakness and numbness.
In 1993, interferon beta became the first drug federally approved for MS because of its ability to block certain types of immune cell activation and the trafficking of immune cells into the brain. While some studies suggest its effects are modest in controlling MS, Calabresi says it works very well in some patients, overall reducing relapses by one-third and inflammation as measured using MRI by more than two-thirds.
Side effects trouble many patients — including flu-like symptoms that tend to occur in the six to eight hours after each injection — but Calabresi says the drug is safer for routine care than some newer oral medications.
Calabresi says his team was eager to test the new formulation, because many MS patients forgo its benefits because of the frequent injection schedule and side effects.
The new version modifies interferon beta by attaching polyethylene glycol (PEG) polymer chemical chains that stabilize the drug. PEG has been proven safe in other medications, shampoos, toothpaste and moisturizers.
For the study, researchers recruited more than 1,500 subjects with MS from 183 sites in 26 countries. For a year, one-third of patients got a placebo shot every two weeks, one-third got 125 micrograms of pegylated interferon beta shots every two weeks and the third group got 125 micrograms of pegylated interferon beta-1a once a month, with a placebo shot given at every other visit.
After a year, those who got pegylated interferon beta-1a every two weeks experienced a 36 percent reduction in the yearly relapse rate compared to the placebo group; the every-four-week group saw a 28 percent reduction. MRI scans revealed 67 percent fewer new or active lesions in the two-week group, while those injected every four weeks only had 28 percent fewer of those lesions.
Both the two- and four-week groups had 38 percent reduction in disability progression on a scale that measures walking speed, vision, strength and sensation, as compared to a placebo group.
The new formulation appeared just as safe as the older one, though Calabresi says that the flu-like symptoms from the long-acting drug lasted closer to 24 hours after each injection in some patients. He called this a trade-off his patients would deem worthwhile.
Data presented April 29 at the American Academy of Neurology suggests that receiving pegylated interferon beta every two weeks is the best dosing schedule.
(Source: hopkinsmedicine.org)
Alzheimer’s and Cancer Link Found
A team led by Houston Methodist Research Institute (HMRI) scientists has found that Alzheimer’s disease and cancer share a pathway in gene transcription, a process essential for cell reproduction and growth. They published their findings in December 2013 in the open access journal Scientific Reports by the Nature Publishing Group.
The scientists used the Lonestar and Stampede supercomputers at the Texas Advanced Computing Center (TACC) at The University of Texas at Austin to analyze and compare data from thousands of genes and to narrow the search for common cell signaling pathways of the two diseases. The Lonestar and Stampede systems are part of the Extreme Science and Engineering Discovery Environment (XSEDE), a single virtual system that scientists use to interactively share computing resources, data and expertise. The research is supported by a gift from the T.T. and W.F. Chao Foundation, and by grants from the National Institutes of Health (NIH).
Lead investigator Stephen Wong, a medical researcher and bioengineer with HMRI, said his study showed a new link between Alzheimer’s disease, the most prevalent form of neurodegenerative disease, and glioblastoma multiform (GBM), the most aggressive form of brain cancer.
"This is the first time people have found that at the molecular mechanism level there are linkages between the two diseases," Wong said.
A 2012 study in Taiwan and a 2013 study in Italy of public health data had shown an inverse association between Alzheimer’s disease, a severe degeneration of the brain’s nerve cells, and with cancer, where cells grow out of control.
"No one understands why this link is there, in a biological sense," Wong said. "And that’s the reason we did this study. I think we are among the first to study it this way."
Mirror, mirror on the wall - who has the fairest ORGANS of them all? Smart surface reveals ‘your’ insides
Mirrors have existed for thousands of years but the looking glass has just been given a 21st century makeover.
A new digital mirror gives people X-ray vision to let them see their insides – complete with bones, organs and muscle on show.
The 3D art installation, called the ‘Primary Intimacy of Being,’ recreates what a body looks like inside and eerily tracks a person’s movements as if they are seeing themselves.
Brain ‘Stones’ Found in Man with Celiac Disease
A young man in Brazil who suffered from throbbing headaches and vision problems for 10 years turned out to have stonelike buildups of calcium in his brain.
The stones were likely a rare complication of the man’s celiac disease, a digestive condition that the man didn’t know he had, according to a new report of his case.
Because of his recurring headaches and vision problems, the man had been treated for migraines, but he hadn’t improved. When doctors did a CT scan, they found patches of calcification in the back of the man’s brain, in the areas that handle vision.
Lab tests showed that although the fluid circulating in the man’s brain was normal, it had higher levels of the antibodies linked to celiac disease, according to the report published in the New England Journal of Medicine.
Smoking’s toll on mentally ill analyzed
Those in the United States with a mental illness diagnosis are much more likely to smoke cigarettes and smoke more heavily, and are less likely to quit smoking than those without mental illness, regardless of their specific diagnosis, a new study by researchers from the Yale School of Medicine shows.
They also found variations in smoking rates and likelihood of quitting among different diagnoses of mental illness. The results are reported in the April issue of the journal Tobacco Control.
Thirty-nine percent of adults with a psychiatric diagnosis smoked compared to 16% without a diagnosis, according to data from the National Epidemiologic Survey on Alcohol and Related Conditions analyzed by researchers. Two out of every three people with drug use disorder smoke, compared to one out of three with social phobia.
“We know that smokers with mental illness are more susceptible to smoking-related disease, and those with mental illness die 25 years earlier than adults without mental illness,” said Sherry McKee, associate professor of psychiatry, and senior author on the study. “Effective smoking cessation treatments are available and we know that smokers with mental illness can quit smoking. We need to address why smokers with mental illness are not being treated for their smoking.”
Over the three-year study period, 22% of smokers with no psychiatric disorders were able to quit smoking, whereas rates of quitting among those with psychiatric disorders were 25% lower. Rates of quitting were lowest among those with dysthymia (10%), agoraphobia (13%), and social phobia (13%). “We also found that individuals with multiple diagnoses had the lowest quit rates,” added Philip Smith, lead author on the study.
This study adds to evidence that smokers with mental illness consume nearly half of all cigarettes in the United States, despite making up a substantially smaller proportion of the population.
Researchers and policymakers are increasingly calling attention to this important public health issue, and this study helps point to a need for interventions and policy that directly help individuals with mental illness quit smoking.
In a cloning first, scientists create stem cells from adults
Scientists have moved a step closer to the goal of creating stem cells perfectly matched to a patient’s DNA in order to treat diseases, they announced on Thursday, creating patient-specific cell lines out of the skin cells of two adult men.
The advance, described online in the journal Cell Stem Cell, is the first time researchers have achieved “therapeutic cloning” of adults. Technically called somatic-cell nuclear transfer, therapeutic cloning means producing embryonic cells genetically identical to a donor, usually for the purpose of using those cells to treat disease.
Study finds modified stem cells offer potential pathway to treat Alzheimer’s disease
UC Irvine neurobiologists have found that genetically modified neural stem cells show positive results when transplanted into the brains of mice with the symptoms and pathology of Alzheimer’s disease. The pre-clinical trial is published in the journal Stem Cells Research and Therapy, and the approach has been shown to work in two different mouse models.
Alzheimer’s disease, one of the most common forms of dementia, is associated with accumulation of the protein amyloid-beta in the brain in the form of plaques. While the search continues for a viable treatment, scientists are now looking into non-pharmaceutical ways to slow onset of this disease.
One option being considered is increasing the production of the enzyme neprilysin, which breaks down amyloid-beta, and shows lower activity in the brains of people with Alzheimer’s disease. Researchers from UC Irvine investigated the potential of decreasing amyloid-beta by delivering neprilysin to mice brains.
“Studies suggest that neprilysin decreases with age and may therefore influence the risk of Alzheimer’s disease,” said Mathew Blurton-Jones, an assistant professor of neurobiology & behavior. “If amyloid accumulation is the driving cause of Alzheimer’s disease, then therapies that either decrease amyloid-beta production or increase its degradation could be beneficial, especially if they are started early enough.”
The brain is protected by a system called the blood-brain-barrier that restricts access of cells, proteins, and drugs to the brain. While the blood-brain-barrier is important for brain health, it also makes it challenging to deliver therapeutic proteins or drugs to the brain. To overcome this, the researchers hypothesized that stem cells could act as an effective delivery vehicle. To test this hypothesis the brains of two different mouse models (3xTg-AD and Thy1-APP) were injected with genetically modified neural stem cells that over-expressed neprilysin.
These genetically modified stem cells were found to produce 25-times more neprilysin than control neural stem cells, but were otherwise equivalent to the control cells. The genetically modified and control stem cells were then transplanted into the hippocampus or subiculum of the mice brains – two areas of the brain that are greatly affected by Alzheimer’s disease. The mice transplanted with genetically modified stem cells were found to have a significant reduction in amyloid-beta plaques within their brains compared to the controls. The effect remained even one month after stem cell transplantation. This new approach could provide a significant advantage over unmodified neural stem cells because neprilysin-expressing cells could not only promote the growth of brain connections but could also target and reduce amyloid-beta pathology.
Before this can be investigated in humans, more work needs to be done to see if this affects the accumulation of soluble forms of amyloid-beta. Further investigation is also needed to determine whether this new approach improves cognition more than the transplantation of un-modified neural stem cells.
“Every mouse model of Alzheimer’s disease is different and develops varying amounts, distribution, and types of amyloid-beta pathology,” Blurton-Jones said. “By studying the same question in two independent transgenic models, we can increase our confidence that these results are meaningful and applicable to Alzheimer’s disease. But there is clearly a great deal more research needed to determine whether this kind of approach could eventually be translated to the clinic.”
Cancer drugs block dementia-linked brain inflammation
A class of drugs developed to treat immune-related conditions and cancer – including one currently in clinical trials for glioblastoma and other tumors – eliminates neural inflammation associated with dementia-linked diseases and brain injuries, according to UC Irvine researchers.
In their study, assistant professor of neurobiology & behavior Kim Green and colleagues discovered that the drugs, which can be delivered orally, eradicated microglia, the primary immune cells of the brain. These cells exacerbate many neural diseases, including Alzheimer’s and Parkinson’s, as well as brain injury.
“Because microglia are implicated in most brain disorders, we feel we’ve found a novel and broadly applicable therapeutic approach,” Green said. “This study presents a new way to not just modulate inflammation in the brain but eliminate it completely, making this a breakthrough option for a range of neuroinflammatory diseases.”
The researchers focused on the impact of a class of drugs called CSF1R inhibitors on microglial function. In mouse models, they learned that inhibition led to the removal of virtually all microglia from the adult central nervous system with no ill effects or deficits in behavior or cognition. Because these cells contribute to most brain diseases – and can harm or kill neurons – the ability to eradicate them is a powerful advance in the treatment of neuroinflammation-linked disorders.
Green said his group tested several selective CSF1R inhibitors that are under investigation as cancer treatments and immune system modulators. Of these compounds, they found the most effective to be a drug called PLX3397, created by Plexxikon Inc., a Berkeley, Calif.-based biotechnology company and member of the Daiichi Sankyo Group. PLX3397 is currently being evaluated in phase one and two clinical trials for multiple cancers, including glioblastoma, melanoma, breast cancer and leukemia.
Crucially, microglial elimination lasted only as long as treatment continued. Withdrawal of inhibitors produced a rapid repopulation of cells that then grew into new microglia, said Green, who’s a member of UC Irvine’s Institute for Memory Impairments and Neurological Disorders.
This means that eradication of these immune cells is fully reversible, allowing researchers to bring microglia back when desired. Green added that this work is the first to describe a new progenitor/potential stem cell in the central nervous system outside of neurogenesis, a discovery that points to novel opportunities for manipulating microglial populations during disease.
(Source: news.uci.edu)