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Scientists are taking the idea of 3D computer printing and catapulting it into the realms of something more suited to science fiction.
The idea of printing a human heart, liver or kidney is becoming closer to reality every day.
Several teams of researchers around the world are working on the process.
And one company, Organovo from San Diego in California has taken on the challenge of using 3D printing technology to create human tissue.
They work with one of the world’s first bio-printers.
The NovoGen MMX is capable of reproducing human tissue in three dimensions.
The idea is ultimately to print entire organs that can be transplanted.
The company’s CEO, Keith Murphy, said: “It prints materials from two deposition heads, cells from one side and gel from the other, with plus or minus 20 microns precision. So you print cells and the cells join together in three dimensions to make one piece of tissue.”
Thirty or so engineers and biologists work on improving every aspect of the technique.
They create what they call ‘bio-ink’ from stem cells that have been grown on fatty tissue or bone marrow.
They are further cultured in flasks, because the process needs several million of them to create just one millimetre of tissue.
They print the cells and a fixing gel layer by layer to form a shape that is controlled by computer.
After that nature takes over and the cells organise themselves into living tissue.
In the lab they can print fragments of heart and lung tissue and blood vessels, but creating an entire organ is still some way off.
Murphy explained: “If you don’t have the ability to create blood vessels inside the system, you’re limited in how thick those can be. So our real limit right now is making things smaller than a millimetre. Over time, as we can print blood vessel networks into larger structures, then we can think about making larger tissues.”
The big advantage of this type of treatment is that the risk of rejection would be eliminated, because the original cells would come from the patient.
In the end it is hoped this technology could ease the shortage of donor organs.
Michael Renard, the company’s vice-president, said:
“It is very hard to know how many years it might take. Obviously there is a lot of research and work that have to be done. Obviously there is equal amounts (sic) of experimentation (and) clinical study, things like this do take time.”
Right now it is the pharmaceutical industry which is the biggest consumer, using printed samples to test new drugs and treatments.
For the moment, this cutting edge technology is still very futuristic.
More about: Medical research, New technologies, San Diego

Paralysed people can now control computer cursor with thought

Published: Monday, Nov 19, 2012, 17:26 IST
Place: Washington, DC | Agency: ANI

In recent years, neuroscientists and neuroengineers working in prosthetics have begun to develop brain-implantable sensors that can measure signals from individual neurons, and after passing those signals through a mathematical decode algorithm, can use them to control computer cursors with thoughts.
Now, a team of Stanford researchers including Indian origins have developed an algorithm, known as ReFIT, that vastly improves the speed and accuracy of neural prosthetics that control computer cursors.
Research associate Dr Vikash Gilja and bioengineering doctoral candidate Paul Nuyujukian led the team.
In side-by-side demonstrations with rhesus monkeys, cursors controlled by the ReFIT algorithm doubled the performance of existing systems and approached performance of the real arm. Better yet, more than four years after implantation, the new system is still going strong, while previous systems have seen a steady decline in performance over time.
"These findings could lead to greatly improved prosthetic system performance and robustness in paralysed people, which we are actively pursuing as part of the FDA Phase-I BrainGate2 clinical trial here at Stanford," said Krishna Shenoy, a professor of electrical engineering, bioengineering and neurobiology at Stanford.
The system relies on a silicon chip implanted into the brain, which records "action potentials" in neural activity from an array of electrode sensors and sends data to a computer. The frequency with which action potentials are generated provides the computer key information about the direction and speed of the user's intended movement
The ReFIT algorithm that decodes these signals represents a departure from earlier models.
The system is able to make adjustments on the fly when while guiding the cursor to a target, just as a hand and eye would work in tandem to move a mouse-cursor onto an icon on a computer desktop. If the cursor were straying too far to the left, for instance, the user likely adjusts their imagined movements to redirect the cursor to the right
To test the new system, the team gave monkeys the task of mentally directing a cursor to a target "an onscreen dot" and holding the cursor there for half a second. ReFIT performed vastly better than previous technology in terms of both speed and accuracy.
The path of the cursor from the starting point to the target was straighter and it reached the target twice as quickly as earlier systems, achieving 75 to 85 percent of the speed of real arms.
"This paper reports very exciting innovations in closed-loop decoding for brain-machine interfaces. These innovations should lead to a significant boost in the control of neuroprosthetic devices and increase the clinical viability of this technology," said Jose Carmena, associate professor of electrical engineering and neuroscience at the University of California Berkeley.
Critical to ReFIT's time-to-target improvement was its superior ability to stop the cursor. While the old model's cursor reached the target almost as fast as ReFIT, it often overshot the destination, requiring additional time and multiple passes to hold the target
The team introduced a second innovation in the way ReFIT encodes information about the position and velocity of the cursor. Gilja said that previous algorithms could interpret neural signals about either the cursor's position or its velocity, but not both at once. ReFIT can do both, resulting in faster, cleaner movements of the curso
The results have been published in the journal Nature Neuroscience.

Oxytocin ('the Love Hormone') Makes Men in Relationships Want to Stay Away From Other Women

By Lindsay Abrams

Nov 16 2012, 8:31 AM ET 19 And it apparently comes in a nasal spray.

eivindw/Flickr

PROBLEM: Oxytocin -- a hormone released by the pituitary gland (notably during both orgasm and childbirth) -- is known to affect our behavior. It promotes bonding, sometimes to the extent of making us conformists. Researchers in Germany suspected that a dose of the so-called "love hormone" during a flirtatious encounter with a sexy stranger might cause us to draw in closer, perhaps going so far as to spark a dangerous liaison.

METHODOLOGY: The research team singled out the most attractive female among them to approach their male subjects. Each of the 57 men had been administered either oxytocin or a placebo via nasal spray prior to the encounter. The attractive researcher would stand about 24 inches away from the subject, and then move toward and away from them. The men were asked to determine when the attractive researcher was at an "ideal distance" and when she got too close, making them feel "slightly uncomfortable."
The men confirmed after the experiment was completed that the attractive researcher was, in fact, attractive.
RESULTS: Unexpectedly, the men who had received oxytocin and who were also in monogamous relationships preferred keeping a significantly greater distance between themselves and the temptress researcher -- the hormone promoted bonding with their significant other, not the stranger. They stayed an average of 4 to 6 inches further back than oxytocin-induced singletons or anyone from the placebo group.

This difference was not observed when the subjects were approached by a male researcher (of undetermined attractiveness), and occurred independently of the amount of eye contact made or whether it was the men or the attractive researcher doing the approaching.
Neither oxytocin nor relationship status affected the men's perception of how attractive the attractive researcher was.
CONCLUSION: Oxytocin promotes monogamy by preventing men from "signaling romantic interest" to other women.
IMPLICATION: If you can't get your hands on the nasal spray, there are plenty of ways in which oxytocin release can be stimulated during a monogamous relationship. Sex, yes, but also hand-holding and touch are known to trigger the hormone. However, the researchers warn, "it is clear that for these potential fidelity-enhancing effects to be revealed, female partners would need to evoke its endogenous release immediately before contexts in which the men might encounter other women."
The full study, "Oxytocin Modulates Social Distance between Males and Females" is published in the Journal of Neuroscience .

E MANN

let's print a heart

http://www.euronews.com/2012/11/13/the-computer-printer-at-the-heart-of-the-matter/

The computer printer at the heart of the matter

Paralysed people can now control computer cursor with thought

Oxytocin ('the Love Hormone') Makes Men in Relationships Want to Stay Away From Other Women