Science Scanner: Windpipe Made from Stem Cells Transplanted into Ailing Man

Posted July 27th, 2011 at 8:22 pm (UTC-4)
Comments are closed

Trachea made from patient’s stem cells being prepared for transplant (Image: David Green, Harvard Bioscience)

In what seems like the plot of a science fiction novel, researchers successfully built and transplanted a new windpipe for an Eritrean man who had a rare but deadly form of tracheal cancer.

Although human tissue has been generated outside the body, the trachea transplant is a first, according to David Green of Harvard Bioscience, which designed and built the bio-reactor used to seed the patient’s stem cells onto a synthetic scaffold holding device.

Professor Paolo Macchiariniut of Karolinska University Hospital in Stockholm performed the surgery.

According to Green, the construction of the scaffold and bio-reactor was done under extreme time pressure, because the patient had a very short period of time in which the operation might be successful.”

The process – as described by Green – seems nothing short of miraculous.

Just a few days before surgery, bone marrow was taken from the patient’s hip bone.  From that, about 40 milliliters of stem cell material were bathed over the surface of the very porous scaffold.

Research is under way already for generating more complex organs like hearts, kidneys and lungs.  While such solid organ transplants may be years away, Green says the next stage is to expand the technology to other hollow organs like ureters, blood vessels and coronary arteries for bypass surgery.  (From: Rebecca Ward/VOA)

Watch VOA reporter Rebecca Ward’s video story:

Scientists Devise an Invisibility Cloak

The cloak of invisibility is a staple in fairy tales and science fiction stories.  In the popular Harry Potter series, the boy wizard is able to sneak into the forbidden areas of his school by wearing a magical cloak.

Now word comes that a group of scientists has, for the first time, devised an invisibility cloak material which hides objects from detection by using light that people can see.

Professor Xiang Zhang at the University of California, Berkeley led the project. His team of researchers were from both UC, Berkley and the Lawrence Berkeley National Laboratory.

According to a new report in the American Chemical Society journal “Nano Letters,” this new device marks a leap forward in cloaking materials. Most of the cloaks used in previous experiments were made from materials that only work with microwave or infrared waves, which can’t be seen by the human eye.

Professor Zhang’s group wanted to go beyond this and develop methods that use light frequencies which can be seen.  The researchers devised a reflective “carpet cloak” out of layers of silicon oxide and silicon nitride etched into special patterns.

The researchers’ carpet cloak works by concealing an object under its layers, and bends the light waves away from the bump that the object makes, so that the surface of the cloak looks flat and smooth like a normal mirror.

The object that was cloaked in this study was microscopic in size, roughly the diameter of a red blood cell.  But, the researchers say that despite this experimental size, their cloaking device has demonstrated that it may be capable of cloaking any object underneath a reflective carpet layer.

And, that unlike other previous demonstrations that were limited to infrared or other invisible light, their work makes actual invisibility for the light that can be seen by the human eye.

Organized Crime Linked to Disappearance of Endangered Species

Organized crime plays a significant role in the worldwide decline of animal species such as rhinos, tigers and elephants,  according to a new paper by Elizabeth Bennett, a respected conservationist at the Wildlife Conservation Society.

Bennett asserts that an immense, increasingly sophisticated illegal trade in wildlife parts is being conducted by organized crime.  This, along with what the group considers to be old and outdated law enforcement methods, leads to the decimation of some of the world’s most beloved species.

The study reports that these syndicates develop and employ sophisticated smuggling operations which penetrate even the most secure wildlife populations.

Much of this illicit trade is reportedly driven by wealthy East Asian markets, which have an insatiable appetite for wildlife parts.

Tricks and methods the crime syndicates employ include hidden compartments in shipping containers, rapidly changing their smuggling routes and using Internet technology – such as e-commerce – to make their locations difficult to detect.

“We have taken our eye off the ball,” Bennett says. “Enforcement is critical – old fashioned in concept but needing increasingly advanced methods – to challenge the ever-more sophisticated methods of smuggling.”

Bennett is concerned some of  the most beloved, charismatic species of wildlife will continue to disappear – possibly to the point of extinction – unless wildlife crimes are taken seriously and resources allocated and committed to tackling the sophisticated, well-funded, globally-linked criminal operations.

Is Your Smart-Phone Habit Forming?

It seems that everyone has and loves their so-called smart phone; so much so that there’s concern over the repetitive and obsessive use of these high-tech devices.

Using data collected in both Finland and the U.S., researchers in Helsinki collected scientific evidence of what they call “checking habits” – repetitive checks of the phone’s menu screen, news, email, contacts and various social applications.

According to their research, a typical “checking” lasts less than 30 seconds and involves opening the screen lock and accessing a single application.

The data indicates that the users engaged in their checking habits as long as they were awake.

Interestingly, the research also goes on to say that these “checkings” don’t happen randomly and for no reason; they are associated with a small set of contexts that trigger them. These include reading email when commuting or checking news while bored.

Although these checking habits have become quite common, the actual smart phone users didn’t consider their checking behavior to be an addiction, but look at it simply as overuse and  an annoyance.

The authors conclude that this uniquely 21st Century behavior has its pros and cons.  On one hand, by making interesting information available so quickly, content developers have made the device more useful.

But, on the other hand, the habits that emerge from this increasingly popular media devour more and more of a person’s free time.

Rick Pantaleo
Rick Pantaleo maintains the Science World blog and writes stories for VOA’s web and radio on a variety of science, technology and health topics. He also occasionally appears on various VOA programs to talk about the latest scientific news. Rick joined VOA in 1992 after a 20 year career in commercial broadcasting.

Comments are closed.