Posts Tagged ‘medicine’
Video: Nanorockets Could Deliver Drugs Within the Body
Replicating a tiny rocket inside the body brings some, well, health concerns. And those are valid; traditional rocket fuels like hydrazine are extremely toxic, highly flammable and dangerously unstable, all of which make it a pretty lousy candidate for a substance you'd like spurting out of a tiny rocket inside your body. Instead, the research team made rolled up metal nanotubes coated with platinum, so that platinum side would be on the inside, and put them in a weak hydrogen peroxide solution. The platinum catalyzed the peroxide, speeding its decomposition into water and oxygen, which forced gas bubbles out of the tube, generating thrust, even in bodily fluids such as blood, saliva or urine.
The rocket can travel up to 200 times its own length per second, and the researchers are able to control its speed by changing the temperature of the fluid. They can also steer the nanorocket using a magnetic field, to precisely direct the drugs to where they are needed.
While using peroxide is infinitely better than toxic rocket fuels, at 0.25 percent peroxide, it's still not completely safe. Researchers would like to dilute the solution further, or even better, create rockets that can be powered by glucose, or another substance already in the body.
Check out the rockets in action in the video below:
Nobel Prize for Medicine Awarded to Scientist Who Prolonged His Own Life With His Research
The prize, awarded jointly to three scientists, celebrates the discovery of the immune system's front-line responders--though one winner succumbed to cancer three days before
One half is awarded jointly to Bruce Beutler and Jules Hoffmann and one half goes to Ralph Steinman. But Steinman died on Friday after a battle with pancreatic cancer, according to in New York, where he was a cell biologist and director of its Center for Immunology and Immune Diseases. He was diagnosed four years ago, and was able to extend his life using a dendritic-cell based immunotherapy of his own design, the university said. He was 68.
The Nobel committee learned he died three hours after it officially bestowed him with the honor, the Nobel Assembly said Monday. Steinman's own university from his family, as officials were compiling information about his Nobel win. Nobel prizes are not awarded posthumously, but the Nobel Foundation's rules specify that if a person wins an award and dies before accepting it, the prize is still presented.
"The decision to award the Nobel Prize to Ralph Steinman was made in good faith, based on the assumption that the Nobel Laureate was alive," the assembly explained . "This was true – though not at the time of the decision – only a day or so previously." The foundation further explains that this situation is unprecedented in the history of the Nobel Prize.
The split award honors research into the immune system's dual nature. A group of first responder cells seek out and destroy invaders and block their ability to replicate, and a second group bats cleanup, producing antibodies that kill cells which have already been infected. Scientists now know a great deal about the genetic rules underlying these systems, but much of this knowledge stands on the shoulders of Beutler, Hoffmann and Steinman, the Nobel Assembly explains.
In 1996, Hoffmann, now 70, was working with some genetically modified fruit flies and infecting them with fungi or bacteria. He discovered that the activation of a gene called Toll is crucial for switching on the initial immune response that allowed his flies to fight off infection. Then in 1998, Beutler, now 54, was searching for a protein receptor involved in regulating septic shock, which results when the body is overwhelmed by infection. He found a mutation in a mouse gene that looked pretty similar to Hoffmann’s Toll gene. This gene codes for a receptor — nicknamed a Toll-like receptor — that binds to a bacterial product involved in septic shock.
Together, the work showed that insects and vertebrates shared similar molecules that activated the innate immune response — and now scientists knew what the molecules looked like. Since then, scientists have identified a dozen more Toll-like receptors in mice and humans.
Decades before that work, Steinman was pioneering research on the secondary immune response, the adaptive response. In 1973, he discovered the dendritic cell — so named because it has little tails, like dendrites in neurons — and set about explaining their function. They serve as the body’s surveillance cells, constantly moving around and sampling their environment. Steinman proved that dendritic cells activate T cells, a class of white blood cells that are important in .
The immune researchers’ work has been crucial in understanding treatment and prevention of disease, from AIDS to cancer. The research is also relevant for understanding auto-immune and inflammatory diseases, in which the immune system attacks the body’s own cells.
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Brain-Scanning "Painometer" Is an Attempt to Measure Pain Objectively
A new, very early version of a "painometer" is being tested at Stanford. The tests are actually sort of medieval-sounding, but to test pain, you've got to inflict pain. Subjects were touched with a heat probe (on the arm, people) and the ensuing brain signals were measured. Those measurements were used to create an algorithm that, the researchers hoped, would be able to indicate pain.
The algorithm does work, though not perfectly; the current accuracy rating is around 81%, which is plenty to show that it works but also not nearly high enough to actually rely on. The other major problem is the relative lack of understanding we have about the nature of pain: this test, says Sean Mackey, an associate professor and member of this project's team, only measures "thermal pain" in a lab setting, and "We should take care not to extrapolate these findings to say we can measure and detect pain in all circumstances."
Still, it's a major step forward to creating a real, objective pain sensor, which could have some pretty major effects on diagnostic medicine, as well as helping those who are too young, too old, or otherwise unable to properly communicate their degree of pain. Then we can get back to making pain medicine out of and .
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The Incredible Shrinking Shot: Needles Get a Pain-Free Makeover
SKIN DEEP
Shots cause pain in two ways: a momentary pinch from piercing the skin and a muscular ache that can last for days. In May, the FDA approved a device that releases flu vaccine directly into the skin, avoiding the muscles (and the ache) altogether. The Fluzone Intradermal microinjector’s needle is about a tenth as long as the needle on a regular syringe and the width of a human hair. And because there are more immune cells in skin than in muscle, doctors could use less vaccine per shot, which could decrease vaccine shortages. The device’s manufacturer, medical company Sanofi Pasteur, says it will start shipping it in the U.S. this fall, just in time for flu season.
LOW PRESSURE PLUNGER
Mosquitoes use a combination of vibrating mouthparts, some smooth and some serrated, to discreetly extract blood. Engineers at Kansai University in Japan created a multipart needle that works like a mosquito’s (possibly the only thing we have to admire about the ): three individually motorized 0.04-inch-long needles—a smooth one for drug delivery flanked by two jagged ones—vibrate while taking turns advancing into the skin. The mechanism requires less than a third of the pressure of a standard needle to penetrate silicone skin test samples. The engineers hypothesize that less pressure causes less skin damage, which could also mean less pain.
PRICKLY PATCH
Researchers at the Georgia Institute of Technology and Emory University have developed a dissolving microneedle patch that could painlessly deliver drugs straight into the skin, leaving behind no sharp parts that could accidentally stick someone and spread disease. About 100 dissolvable, drug-loaded polymer microneedles (each about two hundredths of an inch long) fit on a Band-Aid-like patch the size of a quarter. The patch is easy to apply and can be stored at room temperature, making it particularly useful in poor countries where refrigeration is scarce and doctors may not be available to supervise injections. In clinical studies, the patch delivers drugs with almost no pain. A commercial version could be available in five years.
New Genetic Circuit Detects Cancerous Cells and Forces Them To Commit Suicide
In principle, the circuit works like any other logic circuit: It analyzes multiple inputs and makes a decision. In this case, the circuit really consists of genes that can detect up to five cancer-specific molecules and their concentrations. When all five of those characteristics are present, the circuit makes a positive determination, and then it triggers cell death.
In a new study, researchers from MIT and ETH Zurich worked with HeLa cells, a prolific type of cervical cancer cell. They studied the cells’ microRNA, which regulates gene expression by destroying messenger RNA, the substance that brings the DNA blueprint to the rest of the cell. They eventually pinpointed one microRNA combo that was unique to HeLa cells. This is no small feat by itself — there are about 1,000 versions of miRNA in humans, . Each type of cancer has a unique miRNA profile.
Once they had the right combination, the researchers designed a synthetic gene which codes for a protein that promotes apoptosis, or . The special gene would turn on in the presence of miRNA levels that match the HeLa profile.
“The biocomputer combines the factors using logic operations such as AND and NOT, and only generates the required outcome, namely cell death, when the entire calculation with all the factors results in a logical TRUE value,” Yaakov Benenson, a professor of synthetic biology at ETH Zurich, said .
If the miRNA levels were too high or too low, the gene would not switch on, and the cell would not be killed. Healthy cells, which would also lack the HeLa profile, would be similarly left alone, the researchers said.
The next step would be to test this system in a living animal, but this will be difficult. Current methods use viruses or chemicals to bring foreign DNA inside cells, but these make permanent changes, which could have their own complications. So the method is still far from being usable for cancer treatment, researchers said.
Still, it is an important step toward building a single-cell-level diagnostic method, Benenson said. The research was published in today’s issue of Science.
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New Fluorescent ‘Spinach’ Molecule Illuminates Inner Workings of RNA
Greens are good for you
Researchers have been using for years, tagging molecules and cells to make them glow under certain conditions and when certain changes occur. Now scientists at Weill Cornell Medical School in New York have figured out how to make RNA molecules light up, so they can watch them at work.
Monitoring RNA could help biologists understand how and when the molecules move around in cells, in response to which signals. This could help answer questions about gene expression and about viruses, which use RNA instead of DNA as their genetic material.
Jeremy Paige and colleagues at Weill Cornell worked with derivatives of the green fluorescent protein molecule, called fluorophores, which are what make the molecule glow in certain light wavelengths. They looked for short RNA molecules that could bind to them, the team explains in a paper published today in Science.
They found a host of combinations across the visible spectrum, but just like with jellyfish protein, green was the best. A combination of RNA and fluorophore complexes nicknamed Spinach is just as bright as GFP, the researchers say. What’s more, it doesn’t bleach under microscopic light, and it makes molecules glow faster than regular GFP. They tested it with E. coli and watched bacterial colonies light up.
The method could be a simpler way to tag RNAs for a wide range of applications, the researchers say.
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Half-Synthetic Half-Biological Material Replaces Soft Facial Tissues, Letting Doctors Shape Implants to Order
But a , part biological and part synthetic, could help surgeons rebuild even the hardest to fix disfigurements. Just inject, shape, and blast with green light.
The material, developed by researchers at Johns Hopkins University, blends polyethylene glycol, a synthetic material, with hyaluronic acid, a biological material already in use in soft tissue replacement. It’s injectable, so it requires no surgery, and it’s pliable, so doctors can sculpt it into the proper shape after it has been injected. A specific wavelength of green LED light then solidifies the liquid polymer where it sits, turning the biomaterial's chaotic arrangement of polymer chains into a rigid structure.
The material is also tunable. In lab tests, the researchers mixed various cocktails with different ratios of hyaluronic acid and polyethylene glycol, resulting in implants with different characteristics of pliability and durability--characteristics that would allow doctors to customize the biomaterial for any particular implant. Durability is important, because the implants are not permanent. In those lab tests, the implant with the most longevity only lasted about 500 days before the rat that was hosting it completely absorbed it into its body. That means patients would need to replace their implants roughly every year or so.
The good news is, the absorption of the material has thus far shown no real adverse effects in the rats, or even in humans. The researchers have already tested their biomaterial in three human subjects in Canada. The implants lasted about three months, and none of the subjects experience any unexpected side effects, save a little inflammation around the site of the implant.
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