Pissing Teeth

New teeth grown from urine

Scientists have grown rudimentary teeth out of the most unlikely of sources, human urine. The results, published in Cell Regeneration Journal, showed that urine could be used as a source of stem cells that in turn could be grown into tiny tooth-like structures. The team from China hopes the technique could be developed into a way of replacing lost teeth.

Other stem cell researchers caution that that goal faces many challenges. [No, really?!] Teams of researchers around the world are looking for ways of growing new teeth to replace those lost with age and poor dental hygiene. [*]

The group at the Guangzhou Institutes of Biomedicine and Health used urine as the starting point. Cells which are normally passed from the body, such as those from the lining of the body’s waterworks, are harvested in the laboratory. These collected cells are then coaxed into becoming stem cells. A mix of these cells and other material from a mouse was implanted into the animals.

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It’ll mean a whole new routine in the morning…

The researchers said that after three weeks the bundle of cells started to resemble a tooth: “The tooth-like structure contained dental pulp, dentin, enamel space and enamel organ.” However, the “teeth” were not as hard as natural teeth.

This piece of research is not immediately going to lead to new options for the dentist, but the researchers say it could lead to further studies towards “the final dream of total regeneration of human teeth for clinical therapy”.

Prof. Chris Mason, a stem cell scientist at University College London, said urine was a poor starting point. “It is probably one of the worst sources, there are very few cells in the first place and the efficiency of turning them into stem cells is very low. You just wouldn’t do it in this way.” He also warned that the risk of contamination, such as through bacteria, was much higher than with other sources of cells. Prof. Mason added: “The big challenge here is the teeth have got a pulp with nerve and blood vessels which have to make sure they integrate to get permanent teeth.”

Source: BBC News

[*] Or, as someone who takes immunosuppressants which destroy teeth, this could be useful for people who take immunosuppressants…

Mouse: “I Don’t Like Cheese!” Confusion

False memory planted in mouse’s brain
The feat will help to reveal how more complex false memories, such as of sexual abuse or alien abduction, can arise in people

Scientists have implanted a false memory in the brains of mice in an experiment that they hope will shed light on the well-documented phenomenon whereby people “remember” events or experiences that have never happened.

False memories are a major problem with witness statements in courts of law. Defendants have often been convicted of offences based on eyewitness testimony, only to have their convictions later overturned when DNA or some other corroborating evidence is brought to bear.

In order to study how these false memories might form in the human brain, Susumu Tonegawa, a neuroscientist at the RIKEN-MIT Center for Neural Circuit Genetics, and his team encoded memories in the brains of mice by manipulating individual neurons. He described the results of the study in the latest edition of the journal Science.

Memories of experiences we have had are made from several elements including records of objects, space and time. These records, called engrams, are encoded in physical and chemical changes in brain cells and the connections between them. According to Tonegawa, both false and genuine memories seem to rely on the same brain mechanisms.

In their work, Tonegawa’s team used a technique known as optogenetics, which allows the fine control of individual brain cells. They engineered brain cells in the mouse hippocampus, a part of the brain known to be involved in forming memories, to express the gene for a protein called channelrhodopsin. When cells that contain channelrhodopsin are exposed to blue light, they become activated. The researchers also modified the hippocampus cells so that the channelrhodopsin protein would be produced in whichever brain cells the mouse was using to encode its memory engrams.

In the experiment, Tonegawa’s team placed the mice in a chamber and allowed them to explore it. As they did so, relevant memory-encoding brain cells were producing the channelrhodopsin protein. The next day, the same mice were placed in a second chamber and given a small electric shock, to encode a fear response. At the same time, the researchers shone light into the mouse brains to activate their memories of the first chamber. That way, the mice learned to associate fear of the electric shock with the memory of the first chamber.

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In the final part of the experiment, the team placed the mice back in the first chamber. The mice froze, demonstrating a typical fear response, even though they had never been shocked while there. “We call this ‘incepting’ or implanting false memories in a mouse brain,” Tonegawa told Science. A similar process may occur when powerful false memories are created in humans.

“Humans are very imaginative animals,” said Tonegawa. “Independent of what is happening around you in the outside world, humans constantly have internal activity in the brain. So, just like our mouse, it is quite possible we can associate what we happen to have in our mind with bad or good high-variance ongoing events. In other words, there could be a false association of what you have in your mind rather than what is happening to you.”

He added: “Our study showed that the false memory and the genuine memory are based on very similar, almost identical, brain mechanisms. It is difficult for the false memory bearer to distinguish between them. We hope our future findings along this line will further alert legislatures and legal experts how unreliable memory can be.”

Chris French, head of the Anomalistic Psychology Research Unit at Goldsmiths, University of London, is a leading researcher in false memories in people. He said that the latest results were an important first step in understanding their neural basis.

“Memory researchers have always recognised that memory does not, as is often assumed, work like a video camera, faithfully recording all of the details of anything we experience. Instead, it is a reconstructive process which involves building a specific memory from fragments of real memory traces of the original event but also possibly including information from other sources.”

He cautioned that the false memories created in the mice in the experiments were far simpler than the complex false memories that have generated controversy within psychology and psychiatry, for example false memories of childhood sexual abuse, or even memories for bizarre ritualised satanic abuse, abduction by aliens, or “past lives”.

“Such rich false memories will clearly involve many brain systems and we are still a long way from understanding the processes involved in their formation at the neuronal level,” said Prof French.

Mark Stokes, a neuroscientist at Oxford University, said the experiments were a “tour de force” but that it was important to put them into perspective. “Although the results seem to imply that new memories were formed by the artificial stimulation (rather than the actual environment), this kind of phenomenon is still a long way from most people’s idea of memory,” he said. Rather, he said, it was equivalent to implanting an association that perhaps someone cannot place, but makes them wary of a specific environment for no apparent reason.

“It is unlikely that this kind of pairing could lead to the rich set of associations related to normal memories, although it is possible that over time such pairing could be integrated with other memories to construct a more elaborate false narrative.”

The mouse models created by the MIT team will help scientists ask ever more complex questions about memories in people. “Now that we can reactivate and change the contents of memories in the brain, we can begin asking questions that were once the realm of philosophy,” said Steve Ramirez, a colleague of Tonegawa’s at MIT.

“Are there multiple conditions that lead to the formation of false memories? Can false memories for both pleasurable and aversive events be artificially created? What about false memories for more than just contexts – false memories for objects, food or other mice? These are the once seemingly sci-fi questions that can now be experimentally tackled in the lab.”

As the technology develops, said French, scientists need to think about its uses carefully. “Whatever means are used to implant false memories, we need to be very aware of the ethical issues raised by such procedures – the potential for abuse of such techniques cannot be overstated.”

Source: Guardian

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“I can access your cheese through your dreams. I know how to find cheese from your mind, I know all the tricks! You’ll be trapped in limbo ’til your brains turn to scrambled cheese. And I will lead them on a merry cheese.”

Pandora’s… Pox!*

Giant viruses open Pandora’s box
Genome of largest viruses yet discovered hints at ‘fourth domain’ of life
By Ed Yong

* Well somebody had to say it!

The organism was initially called NLF, for “new life form”. Jean-Michel Claverie and Chantal Abergel, evolutionary biologists at Aix-Marseille University in France, found it in a water sample collected off the coast of Chile, where it seemed to be infecting and killing amoebae. Under a microscope, it appeared as a large, dark spot, about the size of a small bacterial cell.

Later, after the researchers discovered a similar organism in a pond in Australia, they realized that both are viruses — the largest yet found. Each is around 1 micrometre long and 0.5 micrometres across, and their respective genomes top out at 1.9 million and 2.5 million bases — making the viruses larger than many bacteria and even some eukaryotic cells.

But these viruses, described today in Science [1] are more than mere record-breakers — they also hint at unknown parts of the tree of life. Just 7% of their genes match those in existing databases.

“What the hell is going on with the other genes?” asks Claverie. “This opens a Pandora’s box. What kinds of discoveries are going to come from studying the contents?” The researchers call these giants Pandoraviruses.

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“This is a major discovery that substantially expands the complexity of the giant viruses and confirms that viral diversity is still largely underexplored,” says Christelle Desnues, a virologist at the French National Centre for Scientific Research in Marseilles, who was not involved in the study.

Claverie and Abergel have helped to discover other giant viruses — including the first [2] called Mimivirus, in 2003, and Megavirus chilensis, until now the largest virus known [3] in 2011. Pandoravirus salinus came from the same Chilean water sample as M. chilensis. Claverie picked up the second Pandoravirus, P. dulcis, from a pond near Melbourne, where he was attending a conference.

The viruses’ presence on separate continents helped to establish that they were not artefacts of known cells. It also suggests that the Pandoraviruses are widespread, Claverie says.

Indeed, other scientists had previously mistaken them for parasitic or symbiotic bacteria. Rolf Michel, a parasitologist from the Central Institute of the Bundeswehr Medical Service in Koblenz, Germany, found one in 2008, in an amoeba living in the contact lens of a woman with keratitis4. “Reading this stunning article, I recognized that both P. salinus and P. dulcis are almost identical to what we described a few years ago,” he says. “We had no idea that those giant organisms could be viruses at all!”

The researchers showed that Pandoraviruses lack many of the hallmarks of cellular organisms such as bacteria. They do not make their own proteins, produce energy via ATP or reproduce by dividing.

They do, however, contain some of the core genes that are common to giant viruses, and they have a viral life cycle. Under an electron microscope, the researchers saw the viruses being taken up by amoeba hosts, emptying their proteins and DNA into the host cells, commandeering the host-cell nuclei, producing hundreds of new viral particles and, finally, splitting the host cells open.

The researchers are now trying to determine the viruses’ origins by characterizing the unknown genes and the proteins they encode. They have long suspected that giant viruses evolved from cells; if they are right, the ancestors of Pandoraviruses must have been very different from the bacteria, archaea and eukaryotes we have today. “We think that at some point, the dynasty on Earth was much bigger than those three domains,” says Abergel. Some cells gave rise to modern life, and others survived by parasitizing them and evolving into viruses.

The discovery suggests that scientists’ may revise their concept of what a virus looks like. “After reading the article, many people may wonder if they have something on their shelves that might be a giant virus,” says Abergel. “We still have more crazy things in store that we expect to be able to publish next year.”

Source: Nature doi:10.1038/nature.2013.13410
References:
1 Philippe, N. et al. Science 341, 281–286 (2013).
La Scola, B. et al. Science 299, 2033 (2003).
2 Arslan, D., Legendre, M., Seltzer, V., Abergel, C. & Claverie, J.-M. Proc. Natl. Acad. Sci. USA 108, 17486–17491 (2011).
3 Scheid, P., Hauröder, B. & Michel, R. Parasitol. Res. 106, 1371–1377 (2010).

Wicked Sick Map!

Illness and death are the common lot of humanity, but just how they get you depends in part on where in the world you live. This artwork makes that point by combining the beauty of microscopy with the geography of disease. Each continent is painted as microscopic views of the parts of the body that, when diseased or dysfunctional, cause most death or illness for the people who live there.

North America is built from fatty adipose tissue because of its epidemic of obesity. Europe and Russia is represented by brain tissue, representing the neurodegenerative disease of its ageing population. East Asia and the Pacific region is shown as pancreatic tissue, which when diseased causes diabetes. Greenland is marked by a few sperm cells that represent infertility.

The artist, Odra Noel, trained as a doctor, and uses her knowledge of organs and tissues, cell structure and mitochondria in her work. She says she painted this work on silk to evoke old maps.

The disease map of the world is on show from 2 July at the Royal Society’s Summer Science Exhibition in London. This festival of science and technology presents exhibits covering everything from acoustic thermometry to zebrafish genetics.

Image: Odra Noel/Scientific Art / odranoel.eu
© NewScientist.com TYVM

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It’s Only A Wafer Thin Slice

3D atlas aims to unlock the secrets of the mind

Scientists have created the highest resolution 3D digital model yet made of a human brain, showing features as small as 20 micrometres across – thinner than a human hair and almost on the scale of individual cells! Wow!

At 50 times the resolution of any available anatomical atlas of the brain “BigBrain” will give scientists their closest look yet at the structures that underlie aspects of the organ, ranging from cognition and language to ageing and disease. Until now the highest resolution MRI brain scans have only been able to resolve features down to about a millimetre.

Researchers, led by Katrin Amunts, of Heinrich Heine University Düsseldorf, constructed their digital model based upon the preserved brain of a 65-year-old woman that had been set in paraffin. The brain was sliced into more than 7,400 sections, each no more than 20 micrometres thick. The slices were stained to highlight the different types of cell present and then scanned into a computer, creating around a terabyte of data – equivalent to about 120 video DVDs. The slices were then reconstructed into a whole 3D digital brain.

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“Getta your-a brain anti-pasta a-ere!”

Researchers slice a brain preserved in paraffin wax into slivers 20 micromtres thick for the 3D BigBrain atlas. The research was published on in the journal Science and the full data set for BigBrain project is to be made freely available at the CBRAIN Portal. BigBrain, part of the European Human Brain Project, will help scientists put the ever-rising flood of genetic and molecular findings about the brain into context.

“For instance, when you are interested in a common neurodegenerative disorder, like Alzheimer’s disease, you have the first ever brain model where you can look into details of the … brain region important for memory,” said Karl Zilles, an author on the Science paper, and based at the Düsseldorf university. Using this reference model of the brain, he added, would allow teams of researchers around the world to compare their results and tease out differences in the brains of healthy and unwell people. The 3D brain is expected also to help in clinical settings. Amunts said that when, for example, electrodes are inserted into the brains of patients with Parkinson’s disease to help reduce tremors, surgeons could use the BigBrain atlas to position and move the thin wires with far greater precision.

For neuroscientists, BigBrain will act as a scaffold upon which further layers of information about the function of the living brain might be overlaid as discoveries are made. “I think we’re in an era now of very large big science coming to the brain,” said Evans.

Ooh, VIDEO of the 3D Map of the brain! How cool is – oh… a green brain, on a white background…

BigBrain comes in the wake of announcements across the world of projects to map the human brain in ever greater detail. The European commission awarded €500m over 10 years to the Human Brain Project in January, which incorporates the BigBrain consortium. The wider aims of the project are led by Henry Markram, a neuroscientist at the Swiss Federal Institute of Technology, in Lausanne, who wants to use supercomputers to create a digital model of a human brain. In April, the US president, Barack Obama, launched a $100m project called the Brain Research Through Advancing Innovative Neurotechnologies Initiative, to map the human brain in action.

Source: The Guardian, TYVM

All this, and the treatment is still basically electroshock. Hmm.

Walk Like An Egy… A Gorilla

As shoeless visitors strolled along a mechanized gait carpet in the Boston Museum of Science’s Living Laboratory, sensors detected pressure on the mid-outside portion of some pedestrians’ feet. That suggested a midtarsal break—a type of footprint pressure DeSilva and other scientists associated only with gorillas and chimpanzees.

“It was shocking,” said DeSilva, an assistant professor of anthropology at Boston University. “I mean, 80 years of research has argued that humans don’t do this.”

At least 80 years in DeSilva’s field… Last month, when he published his study in the American Journal of Physical Anthropology, two podiatrists said they’d seen a similar variation in patients’ feet. But they weren’t familiar with the term “midtarsal break”—suggesting, DeSilva said, the need for “collaboration with as many different disciplines as possible.”

DeSilva connected his unexpected discovery*—he was originally researching variations in the foot’s arch—to a two-million-year-old fossil human called Australopithecus sediba. DeSilva’s research suggests it moved like today’s apes, which have bendy feet unbound by bones. Chimps, for instance, tumble through the tall trees of the jungle by molding both their hands and their feet around each branch.

In contrast, modern human feet tend to be rigid, with stiff ligaments that maintain bone position and facilitate our bipedal nature. (The same is true of most ancient feet as well; Australopithecus sediba is unique in the fossil record.) With high arches and stiff feet, we spring into our next step. DeSilva says wearing shoes may have played a role in reshaping our feet over the years.

But perhaps some people’s feet can still manage ape-like feats. According to DeSilva’s study, conducted over the past two summers, about 1 in 13 humans may have the midtarsal break in their feet.

Using the gait carpet, a second footprint device, and a camera rig, DeSilva and his colleague Simone Gill, an occupational-therapy researcher, observed a midtarsal break—also known as “floppy feet”—in 32 out of 398 adult participants.

“This [opens a] floodgate of questions,” DeSilva said. “Who are these people? What is it about them that allows them to produce this motion?”**

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DeSilva noted that the floppy-footed folks he watched tended to have flatter feet and higher body mass indexes than the stiff-steppers. They also rolled their feet more: Employing a motion called hyperpronation, they landed on the outside of their feet and rolled dramatically inward. That, said DeSilva, allows the foot to relax its joints and ligaments and create a midtarsal break.

But it’s all relative. Some subjects with floppier feet didn’t technically have a midtarsal break, though their walking pattern came close.

So how do you know if your feet might have a midtarsal break? Take a stroll on sand, DeSilva suggested. Here are a couple of tips:

    Don’t even bother to test your feet at the beach unless they’re flat. If you have high arches, you probably have stiff muscles and ligaments—and decidedly unfloppy feet.
    If you have a midtarsal break, the fold in your foot will pinch the sand upward. Look for a small ridge in the upper-mid portion of the footprint.

This summer, DeSilva and Gill will take MRIs of many foot types and create models of them with 3-D printers. DeSilva will compare that data with the bones of Australopithecus sediba, while Gill will use the models to explore the relationship between foot anatomy and body types.

Source: Nat Geo Mag
* …because we never saw that coming!
** answers on a postcard, please!

Amulet You Wear This…

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A brownish-colored, dry-looking organ — a heart — obsessively pierced by several nails and pins, all varying in size, has a quiet, disturbing visceral impact. It is a charm, created by someone who assembled these charged elements in order to inflict their desires. At first sight, the fragile object seems to come from the dawn of humanity, evoking pagan practices or some exotic civilizations, eons away from our modern days.

Displayed for the first time to the public in 1917, the mummified heart was once the property of Edward Lovett, an eccentric British erudite and wealthy chief cashier in the bank of the City of London who, in his spare time, was the most relentless archivist of his era. A member of the Folklore Society since 1900, Lovett had one very unusual obsession: once off work, he would spend his free time strolling through the slums of Edwardian London to collect evidence of magic and medicinal practices, vernacular beliefs that the century of industrialization and rational sciences hadn’t eliminated. From his urban explorations, conversations with street sellers, sailors, and working class witches, Lovett accumulated an astonishing array of charms, an incredible collection of odds and ends that proved superstitions were an invisible, yet persistent, practice, even in modern England.

The pinned heart is the most fascinating of these amulets and it has, according to Lovett, a very intriguing story. In his 1925 book Magic in Modern London, the folklorist described the incredible story of the mummified relic:

“December – 1911: A cow keeper, who was one of the old school and originally came from Devonshire, had the misfortune to incur the intense wrath of a man of vindictive temper. He threatened to bewitch the poor man’s cows, and two of then died. The cow keeper there upon, took the heart of one of the dead animals, stuck it all over with pins and nails and hung it up in the Chimney of his house… such action is supposed to be of such a serious nature that it brought about an arrangement of a more or less satisfactory character.”

Of course, the concept of attracting good fortune or protection using animal remains seems a bit naive and outdated in the early 20th century, even for Lovett’s contemporaries. But as a matter of fact, this heart was one of many examples of charms and amulets made from carcasses that he found during his metropolitan adventures.

Preserved moles’ paws would be carried in tiny bags to calm toothaches or eradicate cramps, while the tips of rabbits’ tongues would protect against poverty. Bones and skulls would be often carried as amulets, carved or adorned with sterling and worn as necklaces. These often fragile artifacts were materialized solace, shaped out of humans’ hopes and fears.

Source: Laetita Barbier