In a society where pill-popping is the answer to many a medical malady, severely dysfunctional or damaged organs are especially frustrating—they’re usually beyond the reach of any known drugs. Cell-based therapy, though, is no drug: Using patients’ own cells, medical experts have successfully grafted the first engineered-from-scratch urethras.
The story starts with five Mexican boys, aged 10 to 14, whose urethras were damaged beyond repair because of accidents.
“When they first came in, they had a leg bag that drains urine, and they have to carry this bag everywhere they go,” says Dr. Anthony Atala of Wake Forest University in North Carolina. “It’s uncomfortable and painful. So these children were mostly sitting or bed-bound.” [NPR]
Currently the usual treatment calls for an artificial graft, which has a failure chance as high as 50% (and failure here means a lifetime of infections and incontinence). “When an organ or tissue is irreparably damaged or traumatically destroyed, no amount of drugs or mechanical devices will restore the patient back to normal,” regenerative medicine expert Chris Mason, from University College London, told the BBC. Read More
What would you do if calcium deposits were building up in your blood vessels and making it hard to walk, and your doctors said they couldn’t help because they had no idea what disease you had, or how to treat it? Before 2008 you wouldn’t have had many options, but thanks to the National Institute of Health (NIH) you now have at least one: visit the Undiagnosed Diseases Program–where medical researchers just cracked their very first case.
Located in Bethesda, Maryland, this program takes on the medical cases that stump other hospitals. The program has received over 1700 referrals since it started, and has accepted only 330 of them. The results of their first case were published this week in The New England Journal of Medicine, but it all started with dumbfounded doctors and some confusing x-rays:
In 2009, the program received a referral from a Kentucky doctor for two sisters, Paula Allen and Louise Benge, who suffered from joint pain and showed calcium buildup in their arteries in x-rays…. The images “astounded us,” [program director William] Gahl said. The team obtained DNA samples from the sisters and other family members (three of Allen and Benge’s siblings had the same recessive disease) and scanned the DNA for markers called single nucleotide polymorphisms that the researchers used to narrow the location of the disease gene. By also examining this genetic region in two other families with similar disorders, the researchers were able to pinpoint a mutation in a specific gene, NT5E, which is involved in breaking down calcification in the arteries. [ScienceInsider]
Swarms of genetically modified mosquitoes? This isn’t science fiction: The Malaysian government announced earlier this week that it unleashed 6,000 genetically modified (GM) skeeters into a forest as part of a plan to fight dengue fever, a potentially fatal affliction that can affect up to 100 million people each year.
The news appears to have caught the Malaysian media and public by surprise; many recent news stories reported that the study had been postponed after intense protests. As recently as 17 January, the Consumers’ Association of Penang and Sahabat Alam Malaysia, two groups opposing the use of GM insects, called on the National Biosafety Board to revoke its approval for the study. Scientists, too, were under the impression that the work had yet to begin, says medical entomologist Bart Knols of the University of Amsterdam. A 24 January blog post by Mark Benedict, a consultant at the Centers for Disease Control and Prevention in Atlanta who monitors the field closely, mentioned that the Malaysian study was “planned.” [ScienceNOW]
The study itself included the release of 12,000 male mosquitoes in total: 6,000 unaltered and 6,000 GM Aedes aegypti mosquitoes. The goal was to track how well the two types survived and how far they spread. U.K. biotech firm Oxitec created the modified mosquitoes, which don’t produce viable offspring. Researchers hope that if these altered males mate with wild females, it will bring the overall mosquito population down. The strategy has been tried once before in the Grand Cayman Islands, and results from that experiment are due to be published soon.
By combining a cocaine analog with part of a common cold virus, researchers have created a “cocaine vaccine” that tricks the body into attacking the drug, neutralizing its high-giving powers. It has only been tested in mice so far, but the results are good:
“Our very dramatic data shows that we can protect mice against the effects of cocaine, and we think this approach could be very promising in fighting addiction in humans,” study researcher Ronald Crystal, a professor of genetic medicine at Weill Cornell Medical College, said in a statement. [LiveScience]
The immune system doesn’t typically react to cocaine in the blood stream–it’s too small and doesn’t contain the “markers” of an invader. To get the white blood cells to notice it, the researchers strapped it to something the immune system can detect–the outside parts of the virus. The researchers took the outer shell from an adenovirus, which causes some types of the common cold, and removed the parts of the virus that cause illness. Then they linked that recognizable viral shell to a stable molecule similar to cocaine (they also tried it with cocaine itself, the researchers say, but the more-stable analog produced better results).
Forensic scientists of the future may soon have a new tool at their disposal. Given a drop of blood, researchers in the Netherlands have roughly determined the age of the person it came from. But for now, it really is rough–the researchers found they could only estimate a person’s age to within 9 years.
Currently, a crime scene investigator who obtained a spot of blood can check its DNA to see if it matches a known suspect or someone in a law enforcement database, and can use the DNA to determine a few other characteristics like gender and eye color. But age is tougher to estimate. Lead researcher Manfred Kayser, who works on forensic molecular biology at Erasmus University Medical Centre, explains that the best methods of determining age rely on testing bones or teeth, but he wanted to find a method that didn’t require skeletal remains.
It may not be as miraculous as turning water into wine, or as wealth-generating as turning dirt into gold, but we still think this is a very cool trick: Researchers have transformed mature skin cells directly into mature blood cells. Crucially, this was done without reverting the cells to a flexible, “pluripotent” stage in which the cells can grow into any form.
The technique, described in Nature, could lead to lab-grown blood cells for transfusions and transplants for people with bone marrow diseases. Researchers think this new process may be safer than previous methods.
By skipping the pluripotent step, the researchers believe they have skirted the risk that the replacement cells might form dangerous tumors. [Los Angeles Times]
The research team, lead by Mickie Bhatia, coaxed the skin cells into becoming blood cells via a harmless virus that carried a gene called OCT4 into the cells–this reprogrammed the cells, turning their developmental clock back part of the way. Then the cells were incubated in a mixture of cell-stimulating proteins, called cytokines, which directed them on their new paths as either red blood cells, white blood cells, or platelets. The ability to grow a specific kind of blood cell has exciting clinical possibilities.
In an exciting pilot study, blind people equipped with microchips in their retinas were able to see again–at least dimly–and were able to make out shapes.
Ed Yong explains how the experiment helped a study participant named Miikka:
In people like Miikka with retinitis pigmentosa, the light-detecting cells of the retina break down with age. Eberhart Zrenner and a team of German scientists have designed a chip that does the same job as these defunct cells. Just a few millimetres across, it contains 1,500 light-detecting diodes that detect light and convert it into a current. The brighter the light that hits the chip, the stronger the current it puts out. The current is delivered directly to the bipolar cells, which would normally transmit the signals from the retina’s actual light detectors.
Find out more about how the technology works and get the full story on Miikka and his fellow experiment subjects at Not Exactly Rocket Science. And check out the videos of Miikka trying out his new eyes below.
Not Exactly Rocket Science: Retinal Implant Partially Restores Sight in Blind People
80beats: The Eyes Have It: Lab-Made Corneas Restore Vision
80beats: Stem Cell Treatment Lets Those With Scorched Corneas See Again
80beats: The Part of the Brain That Lets the Blind See Without Seeing
80beats: Gene Therapy Cures Color Blindness in Monkeys
Researchers have built miniature human livers in the lab, which could lead to better drug discovery and could even point the way toward implantable artificial organs. The mini-livers seem to act like human livers in the lab, but it remains to be seen how well they’ll survive and perform when transplanted into animals or, maybe one day, humans.
“We are excited about the possibilities this research represents, but must stress that we’re at an early stage and many technical hurdles must be overcome before it could benefit patients,” said Shay Soker, Ph.D., professor of regenerative medicine and project director. “Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, but we must determine whether these organs are safe to use in patients.” [Press release].
The researchers at Wake Forest’s Institute for Regenerative Medicine created livers that weigh about 0.2 ounces each. That’s not nearly large enough to keep a human alive (it would need to be about 80 times larger for that), but getting the organ made was a feat in itself. The livers were made using the extracellular scaffolding from an animal liver, after all of the animal’s cells had been gently removed from it.
For DARPA, the secretive military research agency, it’s not enough for a prosthetic limb to simply resemble a normal one, or for a patient to be able to move it through some remote control. DARPA-backed engineers are attempting to build a system in which peripheral nerves would be reattached to artificial limbs, which could send signals to a brain sensor that could reply. This would be a vast improvement over prosthetics that require conscious directives, and could turn a prosthetic into something that responds the way an ordinary limb would.
Darpa’s after a prosthetic that can record motor-sensory signals right from peripheral nerves (those that are severed when a limb is lost) and then transmit responding feedback signals from the brain. That means an incredibly sensitive platform, “capable of detecting sufficiently strong motor-control signals and distinguishing them from sensory signals and other confounding signals,” in a region packed tightly with nerves. Once signals are detected, they’ll be decoded by algorithms and transmitted to the brain, where a user’s intended movements would be recoded and transmitted back to the prosthetic. [Wired.com]
According to the team behind the system at Johns Hopkins University’s Applied Physics Laboratory, tests on monkeys have shown that the primates have remarkable success controlling a prosthesis through a cortical chip implanted in their brains, and researchers have undertaken some human tests. What remains to be seen, though, is how much dexterity people can get through this process.
When people suffer a concussion, is the evidence of that head trauma just hanging out in their bloodstream, waiting to be found? A U.S. Army project made news late last week by claiming to have found a biomarker for traumatic brain injury, which could allow for a simple diagnosis via blood test.
Make no mistake—a biomarker would be a tremendous medical advance in catching an elusive and hard-to-quantify condition. But don’t get too excited just yet: This was a preliminary study, and some other neuroscientists are not convinced the test will work on in a real, clinical trail.
Army Col. Dallas Hack, who has oversight of the research, says recent data show the blood test, which looks for unique proteins that spill into the blood stream from damaged brain cells, accurately diagnosing mild traumatic brain injury in 34 patients. Doctors can miss these injuries because the damage does not show up on imaging scans, and symptoms such as headaches or dizziness are ignored or downplayed by the victims. [USA Today]
Hack certainly wasn’t going to downplay the achievement by his team, which partners with the Florida-based company Banyan Biomarkers on this project.
Army Col. Dallas Hack says the new technique could rival the discovery of unique proteins in the 1970s that help doctors identify heart disease. “This will in fact do for brain injury what that test did for chest pain,” Hack said. “It’s going to change medicine entirely.” [UPI]