As the deadly facial cancer that has drastically reduced the population of Tasmanian devils continues to spread through the species, the main hope for scientists trying to save them from extinction has been to hunt for devils that might be resistant to the disease, and to try to take advantage of that immunity. Reporting in the Proceedings of the Royal Society B, Kathy Belov and her team say they may finally have done just that: Some devils from northwest Tasmania, they say, are genetically distinct from the rest and could be resistant to the disease.
Belov says that most Tasmanian devils have immune systems so closely related that they’re all susceptible to the disease, which spreads when the devils bite each other on the face and leave behind tumor cells. The bitten devils’ immune systems don’t recognize the tumor cells as foreign, allowing them to take hold. Scientists have given the iconic marsupial as little as 25 years left if efforts are not made to solve the cancer riddle. The population has dwindled by a whopping 70 per cent since the first reported case of devil facial tumour disease in 1996 [Sydney Morning Herald]. Previous research showed that the marsupials are more socially linked that researchers initially believed, which is bad news for those trying to contain the disease.
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In very rare cases, the womb is a dangerous place for a developing fetus. Researchers have found that pregnant women can pass on cancer cells to their unborn babies, if those cancer cells carry a particular genetic mutation. The new study resolves a longstanding puzzle, because in theory any cancer cells that manage to cross the placenta into the baby’s bloodstream should be targeted for destruction by the child’s immune system. But there are records of 17 cases of a mother and baby appearing to share the same cancer – usually leukaemia or melanoma [BBC News].
In the study, which will be published in Proceedings of the National Academy of Sciences, researchers used a genetic “fingerprinting” technique to match the cancer cells found in a mother and baby. The case, involving a Japanese mother aged 28 and her daughter, revealed that both patients’ leukaemic cells carried the identical mutated cancer gene BCR-ABL1 even though the infant had not inherited this gene [The Times]. This meant that the child, who was diagnosed with cancer at the age of 11 months, could not have developed leukemia independently.
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Breaking news from the “Great–one more thing to worry about” file! Microbiologists have looked inside showerheads and found that the dark and damp crannies provide perfect conditions for the growth of bacterial film. A new study in the Proceedings of the National Academy of Sciences looked at showerheads in nine cities and found that they harbor colonies of Mycobacterium avium in particular, a type of microbe that can cause lung ailments. “If you are getting a face full of water when you first turn your shower on, that means you are probably getting a particularly high load of Mycobacterium avium, which may not be too healthy,” says lead author Norman Pace [CNET].
These findings may sound alarming, but the researchers stress that bacteria is everywhere–in the air we breathe and the water we drink–and for the most part, these microbes pose little danger. Study coauthor Leah Feazel says of the shower findings: “This really shouldn’t concern average, healthy people. The main concern is for people who are immune-compromised” [Reuters]. People with AIDS or other immune system disorders should consider getting metal showerheads, which harbor less bacteria than plastic, and changing them often. Anybody else who feels uncomfortable with the idea of a bacterial shower has a couple of options–they can let the shower run for 30 seconds or so before stepping in to flush out some of the microbes, or they can take a bath.
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Image: flickr / stevendepolo
Almost one-third of the cocaine seized in the United States is tainted with the livestock deworming medication levamisole, according to Drug Enforcement Administration documents the Associated Press received.
Levamisole, which can give users a more intense high, weakens the immune system, and has killed at least three people and sickened 100 in Canada and the United States. What’s more, physicians remain largely unaware of the tainted drugs, leaving them helpless to diagnose or treat those affected. “I would think it would be fair to say the vast majority of doctors in the United States have no idea this is going on,” said Eric Lavonas, assistant director of the Rocky Mountain Poison and Drug Center in Denver, where as much as half of the cocaine is believed to contain levamisole. “You can’t diagnose a disease you’ve never heard of” [Associated Press].
Because of the particular distribution mechanism of cocaine, it may be difficult to get the warning out to people at risk. “It’s not like you can put [a warning] on the bottle” [Associated Press], says Lavonas.
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Image: iStockphoto
Gone are the days when scientists considered the spleen a waste of space. Previously, doctors knew that the organ–which is located behind your stomach–performs a variety of functions, from making antibodies to storing red blood cells, but they categorized it as nonessential. A new study published in Science, however, found that while it’s true that people can survive without a spleen, the organ is far from worthless [Science News]. Researchers found that the spleen is actually a crucial storage place for large numbers of monocytes, a type of immune cell.
Monocytes form in bone marrow and rally to fight an infection or repair the body after a trauma such as a heart attack, and scientists previously believed they were stored in the blood stream. In the study, scientists analyzed the monocytes found near the hearts of mice that had experienced a heart attack, and traced nearly half of the cells to the spleen. Later they found that the spleen contains ten times as many monocytes as blood—making it a far more important storehouse [National Geographic].
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Hydrogen peroxide can kill viruses and bacteria, and it’s been used for generations to sterilize wounds and help them heal faster. But a new study published in the journal Nature shows that the substance may also serve as a Pied Piper for white blood cells, summoning them to the site of a wound to promote healing.
Damaged tissue hails a variety of cells to defend the body from infectious agents; one type is white blood cells, which kill by initiating a “respiratory burst,” which releases highly reactive antimicrobial molecules, including hydrogen peroxide produced by the body itself [ScienceNOW Daily News]. But it wasn’t until now that researchers noticed that hydrogen peroxide appeared at the injury site an average of 17 minutes before the immune cells arrived. Study coauthor Phillipp Niethammer explains that after nicking the tail of a zebrafish, “I saw something bursting at the wound,” he says, “but I didn’t see leukocytes there.” That bursting, experiments revealed, was hydrogen peroxide… [I]t appeared as if hydrogen peroxide was bringing leukocytes to the wound rather than the other way around [ScienceNOW Daily News]. Further investigations revealed more about the chain of post-injury events.
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Researchers have found good evidence that the troubling sleep disorder narcolepsy is an autoimmune disease, in which the body’s own immune system attacks healthy brain cells. A new study published in Nature Genetics links narcolepsy to mutations of two genes involved in critical roles in protecting the body from disease. These two variations, they say, are likely conspirators against [cells that produce] hypocretin, a hormone that promotes wakefulness, and that narcoleptics have been found to lack [HealthDay News].
Narcolepsy is a disruptive disorder that can trigger “sleep attacks” without any warning during any normal activity. In addition, some people can experience “cataplexy”, where strong emotions such as anger, surprise, or laughter can trigger an instant loss of muscle strength, which, in some cases, can cause collapse [BBC News]. There is currently no cure for narcolepsy, although the symptoms can be largely controlled with a mix of stimulants and sleep-suppressing medications.
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Stem cell transplants may free type I diabetics of the need for insulin injections, according to a small study in which 20 of 23 patients became insulin-free for up to four years. The study, published in the Journal of the American Medical Association, involved injecting people with stem cells made from their bone marrow cells [Reuters]. Twelve of the patients went for an average of 31 months with no insulin injections. Eight other study participants experienced “transient” insulin independence, meaning they had to start taking insulin again at lower levels [U.S. News and World Report].
The treatment was designed for patients newly diagnosed with type 1 diabetes, a condition that usually develops in childhood and occurs when the immune system goes haywire and starts attacking itself, destroying insulin-producing cells in the pancreas needed to control blood sugar [Reuters]. These beta cells are produced in a part of the pancreas called the islets of Langerhans. In the study, the stem cells were first frozen. The patients were next given a large dose of drugs to knock down their immune systems. The stem cells were then thawed and re-injected back into their bloodstream over about 15 minutes [Australian Broadcasting Corporation]. Over the following days, months, and years, researchers measured their patients’ levels of C-peptides, molecules that indicate how well the body is producing insulin. They found that the stem cell transplants resulted in higher C-peptide levels, indicating healthy beta cells.
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Infusions of stem cells taken from multiple sclerosis patients’ own bone marrows have shown great promise in rolling back symptoms of the disease. In a small study, researchers found that 81 percent of the participants still showed some improvement three years after the treatment, and the rest of the patients had not deteriorated. “All therapies to date … have focused on slowing the progression of disease,” said [lead researcher] Richard Burt…. “What this actually did is that it reversed disability. This is the first time we have turned the tide on this disease” [Chicago Sun-Times].
In multiple sclerosis, or MS, the patients’ immune systems turn on their own central nervous systems, stripping the protective myelin sheaths from nerve fibers and leading to problems with vision, balance, and coordination. The researcher team tested the new treatment on 21 patients in the early stages of the disease, when symptoms alternately flare up and recede. Burt and his colleagues had previously tried using stem cells to reverse this process in patients with advanced stages of the disease, with little success. “If you wait until there’s neuro-degeneration, you’re trying to close the barn door after the horse has already escaped,” says Burt. What you really want to do is stop the autoimmune attack before it causes nerve-cell damage, he adds [New Scientist].
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A leukemia drug has shown great promise in treating multiple sclerosis patients, decreasing neurological symptoms and in some cases even allowing patients to rebuild damaged brain tissue, according to a new study.
Lead researcher Alasdair Coles says the findings offer new hope to patients suffering from the incurable disease: “Not only can this drug stop the disease in its tracks it can reverse patients disabilities. They can walk farther and work for longer. Their lives have started again. This was not expected, the best anyone thought we could hope for with MS drugs was to prevent the condition getting any worse” [Telegraph]. But the drug, named alemtuzumab, also caused some serious side effects that researchers are still investigating.
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