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August 02, 2007

Deep Brain Stimulation

Amazing news:

Brain-Injured Man Speaks After 6 Years

A brain-damaged man who could communicate only with slight eye or thumb movements for six years can speak again, after stimulating electrodes were placed in his brain, researchers report.

The 38-year-old also regained the ability to chew and swallow, which allows him to be spoon-fed, rather than relying on nourishment through a tube in his belly.

The man's brain was injured during an assault, he spent six years with only occasional signs of consciousness and no useful movement of his limbs. In an experiment, researchers implanted electrodes in his brain for a procedure called deep brain stimulation, which is routinely done for Parkinson's disease and some other illnesses.

The article goes on to explain that the man was in a minimally conscious state, as distinct from a permanent vegetative state (who show no signs of awareness of their surroundings whatever.) This method of treatment has proved ineffective for those in a persistent vegetative state, but may offer hope to many of the more than the estimated 100,000 patients currently in a minimally conscious state.

July 28, 2007

Killing Viruses with Light

I like the sound of this:

Visible light pulses knock out viruses in blood

Viruses lurking in biological samples could be killed off with an intense pulse of visible light, new research shows.

Scientists in the US say the technique seems to have significant advantages over alternative methods, including use of UV irradiation or microwaves, as it kills viruses more effectively and safely.

The technique destroys a virus with a pulse of light from a low-power laser. The pulse produces mechanical vibrations in the virus shell, or capsid, irreversibly damaging and disintegrating it, and so "deactivating" the virus for good. The technique might be used to kill HIV, as well as hepatitis C, say the researchers involved.

This approach is a big improvement over other forms of radiation, which can cause a virus to mutate into even nastier forms, or which can damage nearby healthy cells. The laser light is purple in color, and the blast lasts only 100 femtoseconds. Amazing.

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July 02, 2007

Mouse Cells Provide Missing Link

Here's an interesting development:

The discovery of a mouse embryonic stem cell startlingly similar to its human counterpart will likely speed progress toward the regeneration of healthy cells and organ tissue in people, two studies reported Wednesday.

The newly-found "epiblast" stem cells, taken from the inner-most layer of week-old rodent embryos, will provide a better model in testing potential therapies for human diseases and injuries, the researchers said.

"They are a missing link between mouse and human embryonic stem cells," Roger Pedersen, who headed a research team at Cambridge University, told AFP.

Developing treatments at the mouse scale is much, much quicker and more efficient that trying to do it at the human scale -- especially when we're just trying to figure out how things work and what the best way forward will be. Once that best way forward is found, there is still a huge challenge in making what works with mice work with people. This development may help in dealing with that significant challenge.

June 28, 2007

Hope it Ends Better than the Book

Daniel Keyes; classic science fiction story (and later novel) Flowers for Algernon tells of a mentally disabled man who is suddenly made a great genius via a surgical procedure. Before the procedure is performed on him, it is proved on a mouse -- named Algernon.

And now we have this:

In a case of life imitating art, researchers at the Massachusetts Institute of Technology (M.I.T.) reported today that they had successfully reversed mental retardation in mice... Now M.I.T. scientists report in Proceedings of the National Academy of the Sciences USA that they ameliorated brain damage in mice caused by a genetic disorder known as fragile X syndrome by blocking an enzyme involved in cellular development.

Fragile X affects one in 4,000 boys and one in 6,000 girls. It is caused by a mutation in the fragile x mental retardation 1 gene (FMR1)—located on the X sex chromosome— that results in the loss of the fragile x mental retardation protein (FMRP). The resulting illness is characterized by hyperactivity, attention deficit, repetitive behavior, anxiety and cognitive difficulties ranging from learning disability to mental retardation.

When studying the formation of dendrites for a 2004 paper, Mansuo Hayashi, a research affiliate in M.I.T.'s Picower Institute for Learning and Memory, discovered that these structures could be strengthened and altered to transmit information more efficiently by inhibiting nerve cell production of the enzyme called p21-activated kinase (PAK). PAK regulates actin, another protein, which shapes parts of the cell (including the dendrites). When PAK is inhibited, more actin is manufactured and the dendrites are able to properly mature.

What made Keyes' story a tragedy is the eventual reversal of the condition of both the man and the mouse subected to intelligence-enhacing procedure. While it's not clear what applicability this current research will have for human beings -- although it is bound to have some -- there wouldn't appear to be much risk that gene therapy will suddenly reverse itself.

So we'll stay tuned.

June 27, 2007

The Unlikeliest of Places

If you were to ask me where I think lies humanity's greatest hope for conquering AIDS, it probably wouldn't occur to me to guess the home of a desperately poor Kenyan prostitute: a woman who turns dozens of tricks each week (earning a quarter each time) as her only means of feeding her children. Nope, I wouldn't guess there.

But maybe I'd be wrong:

[I]n a way, Munyiva is a fortunate woman -- extraordinarily fortunate to be free of HIV, the virus that causes AIDS. Since the disease emerged in Nairobi in the early 1980s, the sexually transmitted virus has infected 90% of the city's lower-class prostitutes; but somehow Munyiva, 42, has avoided the scourge during her 13 years in that grim line of work. "Perhaps God knows that if he takes me away, my children would suffer," she says.

Munyiva is one of 25 prostitutes in Nairobi who are currently being studied to see if the source of their apparent immunity to HIV can be identified.

A small number of people in other high-risk groups, including some homosexuals and spouses of infected hemophiliacs, have shown resistance to infection. But the Nairobi prostitutes, so frequently exposed to the virus for so many years, provide the strongest evidence yet that people can have a natural immunity to AIDS. If the cause of that protection can be identified, it could spur efforts to develop a vaccine.

I certainly hope that, even if this research provides no immediately fruitful results, these 25 women are remunerated for their participation in such a way that helps to improve their condition. But it's hard to think about them without remembering all the other desperately poor women who face similar circumstances -- and who aren't immune to HIV.

Makes me wish there was something I could do about it. But then, there's plenty we can all do.

April 04, 2007

Interchangeable Blood

I've often wondered when this would become a possibility:

Blood groups 'can be converted'

The technique potentially enables blood from groups A, B and AB to be converted into group O negative, which can be safely transplanted into any patient.

The method, which makes use of newly discovered enzymes, may help relieve shortages of blood for transfusions.

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Of course, this is just a step along the way to fully synthetic blood, which will not only be interchangeable between all the different blood types, but will also provide other benefits as well

Via GeekPress.

January 19, 2007

Re-Growing Nerve Cells

Too late to help Christopher Reeve, alas, but this looks like the beginning of the breakthrough he was looking for:

Stem cells nurture damaged spine: study

BOSTON (Reuters) - Human embryonic stem cells can help regenerate damaged nerves in rats, producing compounds that nurture nerve cells and stimulate the growth of new ones, Geron Corp. said on Wednesday.

Geron had earlier reported that human embryonic stem cells had helped replace myelin, a fatty covering on nerves that is vital to function.

Now, the company's researchers said, they had shown the cells produce multiple nerve growth factors, which are proteins that stimulate the survival and regeneration of neurons.

stemcell.jpg

For victims of paralysis, the ability to replace damaged or missing nerve tissue is the Holy Grail of stem cell research. It will take considerably more than what's been done here before we start seeing people abandoning their crutches and wheelchairs, and even more still before stem cell research offers hope to those who suffer in other ways -- e.g., Parkinson's/ Alzheimer's -- but this is an important step, nonetheless.

Meanwhile, we should be on the lookout for the convergence of other positive developments in this sphere, for example:

Blood stem cells make mouse bone marrow, brain cells

WASHINGTON (Reuters) - Stem cells taken from bone marrow replenished the radiation-ravaged immune systems and bone marrow of mice and can also make brain and liver cells, scientists reported on Monday.

These so-called adult stem cells can grow almost indefinitely in the lab and have many of the other valued properties of more controversial embryonic stem cells, Dr. Catherine Verfaillie of the University of Minnesota and colleagues reported.

"The cells not only survived when transplanted but they completely repopulated the blood system of the mice," Verfaillie said.

Writing in the Journal of Experimental Medicine, the researchers said the findings suggest adult stem cells can be manipulated to regenerate a range of cells and tissues.

bonemarrow.jpg

Replacing brain cells might be more in line with helping the degenerative diseases mentioned above. And of course there will be tremendous benefits for many if the ability to regenerate liver and bone marrow cells pans out.

Additionally, stem cell therapies such as these which can be achieved using adult stem cells represent a kind of Holy Grail in their own right, in that they enable research to move forward without the ethical difficulties raised by embryonic stem cell research. And in addition to these ethical considerations, there's a very practical one -- most stem-cell therapies are intended for adults, or at least for people who stopped being embryos a long time ago. It makes sense to believe that, all things being equal, an individual's own undifferentiated cells -- cells with his or her own DNA -- will prove much more useful in treating any condition than would cells from some other body.

Related postings here and here.

November 02, 2006

Liver from Scratch

miniliver.jpg Well, okay, not scratch but something even better -- stem cells harvested from umbilical cord blood:

British scientists have grown the world's first artificial liver from stem cells in a breakthrough that will one day provide entire organs for transplant.

The technique that created the 'mini-liver', currently the size of a one pence piece, will be developed to create a full-size functioning liver.

Described as a 'Eureka moment' by the Newcastle University researchers, the tissue was created from blood taken from babies' umbilical cords just a few minutes after birth.

Bear in mind, these are small pieces of liver tissue. A fully grown and transplantable liver is still some years away. Even so, this is an enormous step in that direction. Plus, such tissues have uses other than transplantation. They can be subjected to tests that otherwise may have required the use of an animal liver. Not only does this spare the animal subject, results from living human liver tissues will obviously be more relevant and useful.

It's been about six months since we reported on the early success in transplanting lab-grown bladders into human patients. At the time, we wrote:

[A]s Virginia Postrel commented a while back when preparing for kidney donor surgery, this is a procedure that may not be around that much longer. With bladders grown successfully, and hearts and other organs under development, I don't think it will be long before someone in [that] position will have options not quite available today: like getting a new kidney without anyone having to give one up -- a kidney that won't require immune system suppressants to avoid rejection.

It's also satisfying to see something that I thought was very likely come to pass. Here we see individualized organ farming/harvesting without any stem cells/bastocysts/human beings with all the rights and privileges appertaining thereunto (whatever terms suits you) being harmed in the process.

In defending therapeutic cloning some time ago, I wrote:

There is an enormous difference between reproductive and therapeutic cloning. The latter need not require the production of an entire "replacement human;" it may be possible to grow "replacement organs" on their own, or to develop stem cell lines that can be used to treat a wide variety of illnesses and injuries.

Several critics took me to task for this statement. One of them responded as follows:

Therapeutic cloning does require the creation of a whole human embryo... There is no method currently in existence or on the drawing board that would let you grow organs directly, or that could get you to stem cells without an embryo--a replacement human.

I may have bee wrong in my use of the word "cloning," but otherwise my statement seems to hold up pretty well. Here we have embryonic stem cells -- or something much like them -- gathered without an embryo being destroyed and organs grown directly. But maybe my critic was correct. Maybe two and a half years ago, this capability wasn't even "on the drawing board."

In which case, look at what an amazing difference two and a half years can make!

July 26, 2006

(Much) Thicker Than Water

Freeze-Dried Blood.jpg

Although it sounds like a clue from "The Case of the Cosmonaut's Cut", CNet News’s Future Tech Blog is passing on a story from Haaretz that Israeli soldiers may be going into battle carrying their own freeze-dried blood in two years.
Here’s hoping that the product fares better than Northfield Labs’ PolyHeme (PolyHeme product page / PolyHeme Class Action Lawsuit page).

UPDATE: (Wednesday, July 26th, 2006) A gentle nudge from the Senior Editor reminds me to 'accentuate the positive' in this development.

Reducing the mass and volume of transfusion blood, while extending its shelf-life holds implecations well beyond the battlefield. Recently, my wife underwent major surgery and was willing and able to participate in the hospital blood bank's 'autologous donation' program in a small way. By donating a single unit of her own blood in June, to be used in her surgery in July, she was able to reduce her overall impact on our local blood supply, be more secure that the blood she got was both correctly matched to her type and healthy, and contribute actively to the process.

The Israeli product, should it prove to be safe and cost-effective (and, in the world of emergency / intensive medicine, cost-effective does not equal inexpensive), would allow patients to donate their own blood over a longer period before planned surgery, spreading out the stress on the patient's system. It would allow emergency medical personnel (or astronauts...) to pack a significant amount of transfusable blood, in a variety of types and factors, over a relatively long period, in the smallest of packs or vehicles. Finally, it might (and here I am going well beyond my biotechnical knowledge base and speculating rampantly) allow blood to be stored (LN2?) and reconstituted perhaps years later.

July 24, 2006

The Power of Thought

The New York Times (link requires login to NYT news section) reports that Matthew Nagle, a man who has been paralyzed below the shoulders for five years, is now able to draw pictures, change television channels, and control a robot arm and a prosthetic hand all through the power of thought. Channeling that power is a small electronic device which has been implanted in Nagle’s brain and which provides a unique new human/computer interface.

The Times quotes John P. Donoghue, the Brown University professor who led the team that developed the implant as saying, “If your brain can do it, we can tap into it.”

With this new interface, Nagle can move a computer cursor by thinking about it. Of course, the ability to move a computer cursor around may sound trivial to those of us who do it literally thousands of times a day using our fully-functioning arms and hands, but there is nothing trivial about the hope for independence that these kinds of breakthroughs represent for millions. The ability to turn thought into physical motion outside ourselves is so fundamental that we rarely think about it. Yet now, just maybe, we stand on the brink of being able to return that ability to those whom we had every reason to believe had lost it forever.

That is some pretty good news, folks.

November 08, 2005

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