How scientists built the world’s first lab-grown limbs

Harald Ott spent weeks in a lab tending to a tiny rat’s forelimb. He got a special incubator for it, monitored it daily, cared for its every need.

The reason a rat leg was worth all that work? There was no rat attached to it.

Ott, a researcher and thoracic surgeon at Massachusetts General Hospital, is the proud parent of the world’s first lab-grown biolimb — a living, functioning, artificial leg that responds to stimuli and even circulates blood,  the hospital announced Tuesday. Though it’s still a long way off from made-to-order transplants for humans, Ott and other regeneration experts say that the tiny pink rat leg is a step toward the future of artificial limbs.

“This is science fiction coming to life,” Daniel Weiss, a lung regeneration specialist at the University of Vermont College of Medicine, told the New Scientist.

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This Is Your Brain on Drugs

For the Harvard-Northwestern study, published in the April issue of The Journal of Neuroscience, the team scanned the brains of 40 young adults, most from Boston-area colleges. Half were nonusers; half reported smoking for one to six years and showed no signs of dependence. Besides the seven light smokers, nine used three to five days a week and four used, on average, daily. All smokers showed abnormalities in the shape, density and volume of the nucleus accumbens, which “is at the core of motivation, the core of pleasure and pain, and every decision that you make,” explained Dr. Hans Breiter, a co-author of the study and professor of psychiatry and behavioral sciences at Northwestern’s medical school.

Similar changes affected the amygdala, which is fundamental in processing emotions, memories and fear responses.

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Evidence of long-term effects is also building. A study released in 2012 showed that teenagers who were found to be dependent on pot before age 18 and who continued using it into adulthood lost an average of eight I.Q. points by age 38. And last year at Northwestern, Dr. Breiter and colleagues also saw changes in the nucleus accumbens among adults in their early 20s who had smoked daily for three years but had stopped for at least two years.

They had impaired working memories as well. “Working memory is key for learning,” Dr. Breiter said. “If I were to design a substance that is bad for college students, it would be marijuana.”

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Kellogg Eye Center at U of Michigan is doing some cutting edge research in retinal disease
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Training Dogs to Sniff Out Cancer

Since 2004, research has begun to accumulate suggesting that dogs may be able to smell the subtle chemical differences between healthy and cancerous tissue, including bladder cancer, melanomaand cancers of the lung, breast and prostate. But scientists debate whether the research will result in useful medical applications.

Dogs have already been trained to respond to diabetic emergencies, or alert passers-by if an owner is about to have a seizure. And on the cancer front, nonprofit organizations like the In Situ Foundation, based in California, and the Medical Detection Dogs charity in Britain are among a growing number of independent groups sponsoring research into the area.

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The next step will be to build a mechanical, hand-held sensor that can detect that cancer chemical in the clinic. That’s where Charlie Johnson a professor at Penn who specializes in experimental nanophysics, the study of molecular interactions between microscopic materials, comes in.

He is developing what he calls Cyborg sensors, which include biological and mechanical components – a combination of carbon nanotubes and single-stranded DNA that preferentially bond with one specific chemical compound. These precise sensors, in theory, could be programmed to bind to, and detect, the isolated compounds that Dr. Otto’s dogs are singling out.

“We are effectively building an electronic nose,” said Dr. Johnson, who added that a prototype for his ovarian cancer sensor will probably be ready

in the next five years.

Some experts remain skeptical.

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Japanese woman is first recipient of next-generation stem cells

Surgeons implanted retinal tissue created after reverting the patient's own cells to 'pluripotent' state.

A Japanese woman in her 70s is the world's first recipient of cells derived from induced pluripotent stem cells, a technology that has created great expectations since it could offer the same advantages as embryo-derived cells but without some of the controversial aspects and safety concerns.

In a two-hour procedure starting at 14:20 local time today, a team of three eye specialists lead by Yasuo Kurimoto of the Kobe City Medical Center General Hospital, transplanted a 1.3 by 3.0 millimetre sheet of retinal pigment epithelium cells into an eye of the Hyogo prefecture resident, who suffers from age-related macular degeneration.

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Three Myths About the Brain

Good article not only about the brain but also about how scientific misinformation abounds in pop culture..

Uveal Blues

IN the early 19th century, a French neurophysiologist named Pierre Flourens conducted a series of innovative experiments. He successively removed larger and larger portions of brain tissue from a range of animals, including pigeons, chickens and frogs, and observed how their behavior was affected.

His findings were clear and reasonably consistent. “One can remove,” he wrote in 1824, “from the front, or the back, or the top or the side, a certain portion of the cerebral lobes, without destroying their function.” For mental faculties to work properly, it seemed, just a “small part of the lobe” sufficed.

Thus the foundation was laid for a popular myth: that we use only a small portion — 10 percent is the figure most often cited — of our brain. 

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Three Questions for J. Craig Venter

Gene research and Silicon Valley-style computing are starting to merge.

Genome scientist and entrepreneur J. Craig Venter is best known for being the first person to sequence his own genome, back in 2001.

This year, he started a new company, Human Longevity, which intends to sequence one million human genomes by 2020, and ultimately offer Web-based programs to help people store and understand their genetic data (see “Microbes and Metabolites Fuel an Ambitious Aging Project”).

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But that’s going to require some massive data crunching. To get these skills, Venter recruited Franz Och, the machine-learning specialist leading Google Translate. Now Och will apply similar methods to studying genomes in a data science and software shop that Venter is establishing in Mountain View, California.

The hire comes just as Google itself has launched a similar-sounding effort to start collecting biomedical data (see “What’s a Moon Shot Worth These Days”). Venter calls Google’s plans for a biomedical database “a baby step, a much smaller version of what we are doing.”

What’s clear is that genome research and data science are coming together in new ways, and at a much larger scale than ever before. We asked Venter why.

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Unexpected stem cell factories found inside teeth

Development is typically thought to be a one-way street. Stem cells produce cells that mature into specific types, such as the neurons and glia that compose nervous systems, but the reverse isn’t supposed to happen. Yet researchers have now discovered nervous system cells transforming back into stem cells in a very surprising place: inside teeth. 
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Retinal regeneration in zebrafish (w/ Video)

How is it that zebrafish can regenerate retinal cells and we can't?
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Key to Detecting Alzheimer's Early Could Be in the Eye

Scientists have found that certain biological changes in the retina and lens of the eye, and in the sense of smell, may help predict whether people with no or minor memory issues may go on to develop the progressive brain disease, according to findings presented here Sunday at the Alzheimer's Association International Conference.
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But amyloid plaques found in the brain also are known to be deposited in the eye. Two company-funded studies found that those deposits can be detected through noninvasive eye-imaging technology and are highly correlated with the amyloid results from brain imaging.

Cognoptix Inc., a closely held biotech company in Acton, Mass., focuses on amyloid detection in the lens of the eye. CSIRO Australia, the country's national science agency, and its Sacramento, Calif.-based partner, NeuroVision Imaging LLC, have been studying the retina, in the back of the eyes.

The retina is like a "piece of brain outside the brain," said Shaun Frost, a researcher at CSIRO Australia.

The first 40 patients in a 200-participant study showed that retina changes correlated strongly with amyloid plaque development in the brain. The full study will be completed this year, according to Dr. Frost.

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From Volunteers, a DNA Database

Abigail Wark wants to see your areolas.

But only if you are a participant in the Personal Genome Project, a research effort to find 100,000 volunteers as research subjects in the public domain — contributing data from their genomes, microbiomes, health records, tissues and more.

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An About-Face on a Risky Transplant

When the world’s first face transplant was performed in France in 2005, it pushed medical boundaries and made headlines. Yet the procedure’s future was very much in doubt.

The surgeons, operating on a 38-year-old Frenchwoman whose face had been mauled by her pet Labrador, had to surmount the opposition of prestigious medical societies, which declared the procedure unethical and immoral. Critics, including surgeons who had lost out in competing to do the first face transplant, said the pioneering team did not follow ethical and legal guidelines.

But the first comprehensive review of every face transplant reported since then — 28 in seven countries, counting the French case but not two done in Turkey since the review was completed — has removed many of those early doubts.

The report, published online by The Lancet on Sunday, says the procedure is generally safe and feasible, and should be offered to more patients.

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Hearing quality restored with bionic ear technology used for gene therapy

Researchers at UNSW Australia have for the first time used electrical pulses delivered from a cochlear implant to deliver gene therapy, thereby successfully regrowing auditory nerves. The research also heralds a possible new way of treating a range of neurological disorders, including Parkinson's disease, and psychiatric conditions such as depression through this novel way of delivering gene therapy..

Professor Housley and his team at UNSW developed a way of using electrical pulses delivered from the cochlear implant to deliver the DNA to the cells close to the array of implanted electrodes. These cells then produce neurotrophins.

"No-one had tried to use the cochlear implant itself for gene therapy," says Professor Housley. "With our technique, the cochlear implant can be very effective for this."

While the neurotrophin production dropped away after a couple of months, Professor Housley says ultimately the changes in the hearing nerve may be maintained by the ongoing neural activity generated by the cochlear implant.

"We think it's possible that in the future this gene delivery would only add a few minutes to the implant procedure," says the paper's first author, Jeremy Pinyon, whose PhD is based on this work. "The surgeon who installs the device would inject the DNA solution into the cochlea and then fire electrical impulses to trigger the DNA transfer once the implant is inserted."

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Breakthrough in Quest to Grow Body Parts

Lab-Made Vaginas Transplanted Into Patients Whose Own Were Absent Due to Rare Disease

Scientists have successfully transplanted laboratory-made vaginas into four teenage girls whose own were absent because of a rare disease, marking a milestone in the quest to grow structurally complex body parts.

The experiment was published Thursday in the journal Lancet along with another study, in which a separate group of researchers transplanted lab-made nostrils into patients whose noses were damaged by cancer.

The vaginas were created from the patients' own cells and implanted between 2005 and 2008. Today, the women report normal sexual function.

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Dr. Atala began the effort to make a lab-grown vagina in the late 1990s to address disorders that cause some girls to be born without normal vaginas. Cancer and trauma can also lead to vaginal damage or loss. Currently, doctors reconstruct the vagina using a patient's own skin or part of the intestine, but both cause other physical problems.

The effort immediately hit a roadblock: "We couldn't even get the vaginal mucosal cells to grow outside the body," Dr. Atala recalled. After solving that problem, the team needed to find something to serve as a scaffold—or skeleton—on which the cells would sit. They rejected various options, including the material used to make surgical sutures, before settling on one they liked: tissue from a pig's intestine.

The pig tissue was first bathed in detergent, which removed the original cells and left behind a scaffold-like structure made from collagen. This was coated on one side with epithelial cells, which line the body's cavities, and which had been obtained via a biopsy of the patient's external genitals. The other side was coated with smooth muscle cells, also from the patient. When the scaffold was placed in an incubator and nourished with chemicals and oxygen, the cells began to grow.

The scaffold was hand-sewn into a vagina-like shape and tailored to fit the patient. Surgeons created a cavity in the patient's pelvis and sutured the cell-populated scaffold to reproductive structures, including the uterus.

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Do Brain Workouts Work? Science Isn’t Sure

For a $14.95 monthly membership, the website Lumosity promises to “train” your brain with games designed to stave off mental decline. Users view a quick succession of bird images and numbers to test attention span, for instance, or match increasingly complex tile patterns to challenge memory.

WIRED WELL

Personal technology for health and fitness.

While Lumosity is perhaps the best known of the brain-game websites, with 50 million subscribers in 180 countries, the cognitive training business is booming. Happy Neuron of Mountain View, Calif., promises “brain fitness for life.” Cogmed, owned by the British education company Pearson, says its training program will give students “improved attention and capacity for learning.” The Israeli firm Neuronix is developing a brain stimulation and cognitive training program that the company calls a “new hope forAlzheimer’s disease.”

And last month, in a move that could significantly improve the financial prospects for brain-game developers, the Centers for Medicare and Medicaid Services began seeking comments on a proposal that would, in some cases, reimburse the cost of “memory fitness activities.”

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The problem, Dr. Doraiswamy added, is that the science of cognitive training has not kept up with the hype.

“Almost all the marketing claims made by all the companies go beyond the data,” he said. “We need large national studies before you can conclude that it’s ready for prime time.”

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The Fat Drug

IF you walk into a farm-supply store today, you’re likely to find a bag of antibiotic powder that claims to boost the growth of poultry and livestock. That’s because decades of agricultural research has shown that antibiotics seem to flip a switch in young animals’ bodies, helping them pack on pounds. Manufacturers brag about the miraculous effects of feeding antibiotics to chicks and nursing calves. Dusty agricultural journals attest to the ways in which the drugs can act like a kind of superfood to produce cheap meat.

But what if that meat is us? Recently, a group of medical investigators have begun to wonder whether antibiotics might cause the same growth promotion in humans.

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How to generate new neurons in brains, spinal cords of living adult mammals

No stem-cell transplants required

March 4, 2014

UT Southwestern Medical Center researchers have created new nerve cells in the brains and spinal cords of living mammals without the need for stem cell transplants to replenish lost cells.

In a comment to a KurzweilAI news article, “Brain signals from a primate directly move paralyzed limbs in another primate ‘avatar,’” “Cazbot” wondered if “a sort of ‘neural jumper’ could be used to bridge damaged sections of spinal chord.”

This new research indicates it may someday be possible to do just that — by regenerating neurons from the body’s own cells to repair traumatic brain injury or spinal cord damage, or to treat conditions such as Alzheimer’s disease.

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Scientists in UT Southwestern’s Department of Molecular Biology first successfully turned astrocytes — the most common non-neuronal brain cells — into neurons that then formed networks in mice. They have now successfully turned scar-forming astrocytes in the spinal cords of adult mice into neurons. The latest findings are published today inNature Communications and follow previous findings published in Nature Cell Biology.

“Our earlier work was the first to clearly show in vivo (in a living animal) that mature astrocytes can be reprogrammed to become functional neurons without the need of cell transplantation. The current study did something similar in the spine, turning scar-forming astrocytes into progenitor cells called neuroblasts that regenerated into neurons,” saidChun-Li Zhang, assistant professor of molecular biology at UT Southwestern and senior author of both studies.

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3D Printing Low-Cost Prosthetics Parts in Uganda

Researchers at the University of Toronto, in collaboration with Autodesk Research (Toronto, Ontario) and CBM Canada (Stouffville, Ontario) are employing 3D-printing techniques to produce cheap, fast, and easily customizable prosthetic sockets for use in the developing world. I was invited to check out the lab on behalf of Medgadget to get a better idea of what’s the latest in custom printed prosthetic devices.
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Ryan Schmidt: We first create a 3D scan of the limb using an Xbox Kinect. We can bring that digital limb into Autodesk Meshmixer, smooth out the rough scan mesh, and use it directly to design the socket. We create a molded “bucket” around the limb’s contours, and can use Meshmixer to quickly push and pull parts of the design to modify its shape. In the end, the model is sent to a 3D printer, which prints the socket in a few hours using PLA (poly lactic acid), a thermoplastic that is easily modifiable with heat. This method can make a typical socket for under $10;;

Medgadget: What benefits does this 3D printing method have over the traditional method?

Matt Ratto: The traditional method involves wrapping an amputated limb with a plastic mold to first create a negative cast. Once that dries, plaster is poured into the negative cast to make a positive cast, which serves as a representation of the actual limb. Finally, a socket is molded around the positive cast, and can be used upon curing.

Ryan Schmidt: The traditional method is very time-consuming, especially if iteration needs to be done. It’s a destructive process, so any modifications destroy the original molds, and that information is lost. The method we use with 3D printing allows for a quick scan to digitize the limb, simplifying the process. It allows for quick and non-destructive modifications.

3D scanning has become increasingly widespread, and the capabilities of 3D printers have been steadily improving. The missing piece now, and the novelty of Meshmixer, is the ability to deal with the data and models and link the scanning and fabrication.

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16 Depressing Facts to Ruin Your Friend's Day

Perfect icebreakers to jumpstart a conversation are difficult to come by.

Fortunately, there's no shortage of depressing facts that are a surefire way to get people talking. Regale fellow party-goers with tales of the world's loneliest animal, or bring down the mood with some harrowing statistics regarding our favorite medical practice.

SEE ALSO: 6 Depressing Facts About Love

Become the Debbie Downer you've always hoped to be with these depressing facts that will seriously bum you out. Or at least get a conversation going.

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Newly developed chemical restores light perception in blind mice

Richard Kramer of the University of California, Berkeley and his colleagues have invented a “photoswitch” chemical named DENAQ that confers light sensitivity on normally light-insensitive retinal ganglion cells, restoring light perception in blind mice.*
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