From the original Science article:
"To protect the token from accidental damage, it can be encapsulated in a scratch-resistant material, and the multiscale Gabor transform can be tuned to reject speckle features arising from surface scratches while preserving features that originate from the internal microstructure. "
>Personally I have crohns disease. A disease linked to the consumption of cows milk.
Well, there is a controversial theory that Crohn's disease may be caused by a mycobacterium that is carried by cows, although no one has ever shown that transmission from cow-to-human via milk happens in the real world. If the rest of your statements are based on logic like this, I'm not impressed. Anyway, if you are so convinced it's milk-related, have you tried clarithromycin/rifabutin therapy?
PS. Yes, I know someone personally who has Crohn's disease and I know it sucks.
>The press release says this is how they identified the enzyme
There's the problem right there-- you are relying on a press release for scientific information. I'm glad to see that you are using analyzing what you read, but GIGO...
I wish I could say something insightful, but the peer-reviewed data on this won't be publically available until 5 October (according to the journal where it will be published, Genome Research). Trying to interpret what this actually means from a press release is futile.
This reminds me of a skit some friends of mine did at a biology grad school party a decade ago, back when Photoshop was still pretty new... They made up a fake ad with a software product called "GelDoc". The opening scence had some sad scientists complaining about how they couldn't get the band they wanted on their gel, then they used "GelDoc" to paste in the needed band (doctoring the results)... the tag line was something like "Can't get the results you need for publication? GelDoc can solve your problems!"
The scary part was that several years after that a biologist was caught falsifying results with an error like Schon's-- he had reused a gel photo from an older paper and the reviewer recognized it. I can't remember the guy's name at the moment. But, it put the same question into my head... "How many are *not* caught"? Fortunately if the reviewers don't see it, the person's competitors or collaborators will eventually find they can't repeat the fraudulent result. Redundancy is built into the system.
In case anybody's wondering, this particular technique is not useful for sex change surgery because the scientists start with tissue samples from the subject and grow them up to make more. This is great in that it avoids any graft-vs-host problems, but if you start out with no penis tissue, you can't make any. It could some day be very helpful for boys born with a micropenis, or following certain types of accidents which befall genetic males... (are you cringing now?)
>Aren't there a whole number of organs they could have "experimented" with?
Clearly yes. In fact the same lab is also working with hearts , kidneys, and bladder cells and there are many other research groups studying tissue engineering with various tissues, for example this group at Mass. General. A key word here is tissue-- typically they are using a fairly homogenous population of cells and putting it on a matrix in the right shape. Limbs are coming, but they need to have skin, muscle, nerves and bone all made and assembled properly, which is very complex compared to just growing, say, some skin.
>20% of people who the surgery doesn't work for That's the statistic for outcome at 3 months, but the original research article says that by 18 months, 90% of the surgery subjects were improved. And, 41% out of the splint group went on to get the surgery during that time. An interesting statistic that doesn't make it into the popular press is this one, quoting the JAMA article, " After 18 months, only 29 of 79 patients indicated to be improved by splinting alone, resulting in a final success rate of 37% for the splint group." So, your point about the people who are not helped by splints going on to get surgery is a good one, but in the slightly longer term, the choice looks like 90% chance of cure vs 37% chance of relieving symptoms.
According to the JAMA article that this data comes from, and my own searches of Pubmed, there's only been one randomized trial with surgery, and that was also comparing vs splinting. There have been few rigorous studies of the effectiveness of 'conservative' treatments like splinting. I'm pretty surprised by this!
My understanding is the surgery actually fixes the problem (at least for strictly defined carpal tunnel syndrome, where the pinched nerve is in the wrist) since the ligament that is pressing into the nerve is actually cut back. To cite a personal example, my mom had carpal tunnel way back in the late 70s when no one had heard of it and has been fine since she got the surgery in about 1980. I think it's very very rare to have repeated surgical treatment.
This story had some media coverage about 5 years ago... For example, here's a Boston Globe bit with some useful details: http://search.boston.com/globe/search/st ories/heal th/how_and_why/101397.htm A more recent article which is much better than the lame ABC story is on Wired: http://www.wired.com/wired/archive/10.06/m elanotan.html
Actually, the "medical" application is in preventing skin cancer. That's why the Australians (who have really high skin cancer rates) are the ones pushing this as a commercial development, though the chemical was first identified in the US.
Now, if we can just keep getting people/governments/companies to PAY for pure research based on intellectual curiosity, instead of wanting instant gratification....
see the "Why now" thread-- actually Dr. Kellar Autumn (BBC's error) has published a new study with additional findings about this, this month in PNAS. The pop press has watered the story down so far that the casual reader can't tell there are any new findings since 2000, but there are....
Yes, the explanation is the new PNAS article. Unfortunately the pop press has simplified the new developments to the point where they sound exactly like the "old" developments, so everyone is assuming scientists have not learned anything new since 2000... Actually they have done new things, but it's too difficult for the AP writers to explain! Here's that PNAS abstract:
"Geckos have evolved one of the most versatile and effective adhesives known. The mechanism of dry adhesion in the millions of setae on the toes of geckos has been the focus of scientific study for over a century. We provide the first direct experimental evidence for dry adhesion of gecko setae by van der Waals forces, and reject the use of mechanisms relying on high surface polarity, including capillary adhesion. The toes of live Tokay geckos were highly hydrophobic, and adhered equally well to strongly hydrophobic and strongly hydrophilic, polarizable surfaces. Adhesion of a single isolated gecko seta was equally effective on the hydrophobic and hydrophilic surfaces of a microelectro-mechanical systems force sensor. A van der Waals mechanism implies that the remarkable adhesive properties of gecko setae are merely a result of the size and shape of the tips, and are not strongly affected by surface chemistry. Theory predicts greater adhesive forces simply from subdividing setae to increase surface density, and suggests a possible design principle underlying the repeated, convergent evolution of dry adhesive microstructures in gecko, anoles, skinks, and insects. Estimates using a standard adhesion model and our measured forces come remarkably close to predicting the tip size of Tokay gecko seta. We verified the dependence on size and not surface type by using physical models of setal tips nanofabricated from two different materials. Both artificial setal tips stuck as predicted and provide a path to manufacturing the first dry, adhesive microstructures."
In sum, sounds like the new bits are 1)more evidence for the van der Waals model of adhesion 2)model 'setal tips' were made that behave like the natural ones
"hasn't been mentioned"? Even the short article that this discussion is linked to includes this statement,
"Several significant problems need to be overcome before xenotransplantation can be attempted in humans, particularly the danger that pig viruses might cross the species barrier and create a new disease. "
Yes, it is a concern, but nobody's hiding it. And the sky is not falling.
See the "the only thing I'd worry about.." thread for more on this... Basically the way this phage enzyme binds to its target bacterium surface molecule is the same sort of very very specific "3D lock and key" fit that an antibody has for its target molecule. The original Nature article is not very well explained by Yahoonews, but the scientists did testing, and the PlyG did not bind at all to several closely-related (Bacillus) bacteria, though it did bind to one that is almost identical to anthrax. Humans aren't the normal place these bacteria are found, so it's extremely unlikely that any "normal" bacteria could be targetted by this.
I'm trying to think of a non-biology comparison here... uh, how about thinking of the recognition of a bacterium by the phage enzyme in terms of cryptography -- the phage has a key to get into this particular bacterial species, but it's really unlikely that the same key would work on any other type of bacteria.
Oh, and viruses leave the body all the time, eg folks pick up cold viruses from other people's sneezes.
>Some bright guy might attempt to engineer a broad spectrum bacteriophage
You'll be reassured to know that phages have exquisite specificity for their targets-- according to the Nature article: "High-affinity binding (the affinity constant Ka = 3-6 10X^8, similar to affinity-matured antibodies) is directed towards species- or strain-specific cell-wall carbohydrates". So creating a broad-specificity phage would be like making a broad-specifity antibody-- kind of a contradiction in terms.
>So you eat bateria to kill a virus. No, actually you get an injection with a purified enzyme from a type of virus, that kills the bacteria. Anthrax is a bacterial species.
>(I thought viruses merged with your DNA...). That's only retroviruses. In this case the target of the virus is the bacteria, so if it were going to integrate into any DNA it would be the bacterial DNA. But, this bacteriophage is not a retrovirus, and only the purified lysin protein is being used, not the whole virus.
>There is [sic] only 115 streches [ebi.ac.uk] of DNA that are known in public databases
Yes, but >100 of the DNA sequences that come up in that search are for endogenous retroviruses or microsatellite DNA (repetitive junk), which don't tell you anything about the mammoth genes' coding sequences... The few actual mammoth sequences that are known include the 12S RNA and cytochrome B (J Mol Evol 1998 Mar;46(3):314-26) which are mitochondrial genes. It makes sense that the researchers have managed to get these sorts of things (mitochondrial genes, repetitive elements) since they would be present at multiple copies per cell, but learning about ordinary single copy genes is much more difficult.
.
Of course, knowing about the mammoth's DNA doesn't really matter for these scientists since they are trying to use frozen mammoth sperm.
Why not clone the world's best search and rescue dog, instead of someone's family pet ?
Simple, that's what the people with the funding chose to do. Same thing in this case.
That, and as far as I know, there aren't any frozen Dodos around waiting to be used for donor cells/DNA.
>The cloning process involves putting DNA from the mammoth into an Asian elephant's egg that has been stripped of elephant genes. >So even though an elephant would give birth, the baby would be a mammoth, not a hybrid Well, the two teams have the same goal, but this technique would produce an actual clone (well, ok, except that it would have Asian elephant mitochondrial DNA). The Japanese team in the news now is actually trying to make a hybrid, by "impregnating an Indian elephant with mammoth sperm ".
Slashdot Mirror
From the original Science article: "To protect the token from accidental damage, it can be encapsulated in a scratch-resistant material, and the multiscale Gabor transform can be tuned to reject speckle features arising from surface scratches while preserving features that originate from the internal microstructure. "
Well, there is a controversial theory that Crohn's disease may be caused by a mycobacterium that is carried by cows, although no one has ever shown that transmission from cow-to-human via milk happens in the real world. If the rest of your statements are based on logic like this, I'm not impressed. Anyway, if you are so convinced it's milk-related, have you tried clarithromycin/rifabutin therapy?
PS. Yes, I know someone personally who has Crohn's disease and I know it sucks.
There's the problem right there-- you are relying on a press release for scientific information. I'm glad to see that you are using analyzing what you read, but GIGO...
I wish I could say something insightful, but the peer-reviewed data on this won't be publically available until 5 October (according to the journal where it will be published, Genome Research). Trying to interpret what this actually means from a press release is futile.
This reminds me of a skit some friends of mine did at a biology grad school party a decade ago, back when Photoshop was still pretty new... They made up a fake ad with a software product called "GelDoc". The opening scence had some sad scientists complaining about how they couldn't get the band they wanted on their gel, then they used "GelDoc" to paste in the needed band (doctoring the results)... the tag line was something like "Can't get the results you need for publication? GelDoc can solve your problems!"
The scary part was that several years after that a biologist was caught falsifying results with an error like Schon's-- he had reused a gel photo from an older paper and the reviewer recognized it. I can't remember the guy's name at the moment. But, it put the same question into my head... "How many are *not* caught"? Fortunately if the reviewers don't see it, the person's competitors or collaborators will eventually find they can't repeat the fraudulent result. Redundancy is built into the system.
In case anybody's wondering, this particular technique is not useful for sex change surgery because the scientists start with tissue samples from the subject and grow them up to make more. This is great in that it avoids any graft-vs-host problems, but if you start out with no penis tissue, you can't make any. It could some day be very helpful for boys born with a micropenis, or following certain types of accidents which befall genetic males... (are you cringing now?)
Clearly yes. In fact the same lab is also working with hearts , kidneys, and bladder cells and there are many other research groups studying tissue engineering with various tissues, for example this group at Mass. General. A key word here is tissue-- typically they are using a fairly homogenous population of cells and putting it on a matrix in the right shape. Limbs are coming, but they need to have skin, muscle, nerves and bone all made and assembled properly, which is very complex compared to just growing, say, some skin.
>20% of people who the surgery doesn't work for
That's the statistic for outcome at 3 months, but the original research article says that by 18 months, 90% of the surgery subjects were improved. And, 41% out of the splint group went on to get the surgery during that time.
An interesting statistic that doesn't make it into the popular press is this one, quoting the JAMA article,
" After 18 months, only 29 of 79 patients indicated to be improved by splinting alone, resulting in a final success rate of 37% for the splint group."
So, your point about the people who are not helped by splints going on to get surgery is a good one, but in the slightly longer term, the choice looks like 90% chance of cure vs 37% chance of relieving symptoms.
According to the JAMA article that this data comes from, and my own searches of Pubmed, there's only been one randomized trial with surgery, and that was also comparing vs splinting. There have been few rigorous studies of the effectiveness of 'conservative' treatments like splinting. I'm pretty surprised by this! My understanding is the surgery actually fixes the problem (at least for strictly defined carpal tunnel syndrome, where the pinched nerve is in the wrist) since the ligament that is pressing into the nerve is actually cut back. To cite a personal example, my mom had carpal tunnel way back in the late 70s when no one had heard of it and has been fine since she got the surgery in about 1980. I think it's very very rare to have repeated surgical treatment.
This story had some media coverage about 5 years ago... For example, here's a Boston Globe bit with some useful details:t ories/heal th/how_and_why/101397.htm m elanotan .html
http://search.boston.com/globe/search/s
A more recent article which is much better than the lame ABC story is on Wired:
http://www.wired.com/wired/archive/10.06/
Actually, the "medical" application is in preventing skin cancer. That's why the Australians (who have really high skin cancer rates) are the ones pushing this as a commercial development, though the chemical was first identified in the US.
Yes, that's the same thing.
Now, if we can just keep getting people/governments/companies to PAY for pure research based on intellectual curiosity, instead of wanting instant gratification ....
see the "Why now" thread-- actually Dr. Kellar Autumn (BBC's error) has published a new study with additional findings about this, this month in PNAS. The pop press has watered the story down so far that the casual reader can't tell there are any new findings since 2000, but there are....
Yes, the explanation is the new PNAS article. Unfortunately the pop press has simplified the new developments to the point where they sound exactly like the "old" developments, so everyone is assuming scientists have not learned anything new since 2000... Actually they have done new things, but it's too difficult for the AP writers to explain! Here's that PNAS abstract:
"Geckos have evolved one of the most versatile and effective adhesives known. The mechanism of dry adhesion in the millions of setae on the toes of geckos has been the focus of scientific study for over a century. We provide the first direct experimental evidence for dry adhesion of gecko setae by van der Waals forces, and reject the use of mechanisms relying on high surface polarity, including capillary adhesion. The toes of live Tokay geckos were highly hydrophobic, and adhered equally well to strongly hydrophobic and strongly hydrophilic, polarizable surfaces. Adhesion of a single isolated gecko seta was equally effective on the hydrophobic and hydrophilic surfaces of a microelectro-mechanical systems force sensor. A van der Waals mechanism implies that the remarkable adhesive properties of gecko setae are merely a result of the size and shape of the tips, and are not strongly affected by surface chemistry. Theory predicts greater adhesive forces simply from subdividing setae to increase surface density, and suggests a possible design principle underlying the repeated, convergent evolution of dry adhesive microstructures in gecko, anoles, skinks, and insects. Estimates using a standard adhesion model and our measured forces come remarkably close to predicting the tip size of Tokay gecko seta. We verified the dependence on size and not surface type by using physical models of setal tips nanofabricated from two different materials. Both artificial setal tips stuck as predicted and provide a path to manufacturing the first dry, adhesive microstructures."
In sum, sounds like the new bits are
1)more evidence for the van der Waals model of adhesion
2)model 'setal tips' were made that behave like the natural ones
"hasn't been mentioned"? Even the short article that this discussion is linked to includes this statement, "Several significant problems need to be overcome before xenotransplantation can be attempted in humans, particularly the danger that pig viruses might cross the species barrier and create a new disease. " Yes, it is a concern, but nobody's hiding it. And the sky is not falling.
See the "the only thing I'd worry about.." thread for more on this... Basically the way this phage enzyme binds to its target bacterium surface molecule is the same sort of very very specific "3D lock and key" fit that an antibody has for its target molecule. The original Nature article is not very well explained by Yahoonews, but the scientists did testing, and the PlyG did not bind at all to several closely-related (Bacillus) bacteria, though it did bind to one that is almost identical to anthrax. Humans aren't the normal place these bacteria are found, so it's extremely unlikely that any "normal" bacteria could be targetted by this.
I'm trying to think of a non-biology comparison here... uh, how about thinking of the recognition of a bacterium by the phage enzyme in terms of cryptography -- the phage has a key to get into this particular bacterial species, but it's really unlikely that the same key would work on any other type of bacteria.
Oh, and viruses leave the body all the time, eg folks pick up cold viruses from other people's sneezes.
>Some bright guy might attempt to engineer a broad spectrum bacteriophage
You'll be reassured to know that phages have exquisite specificity for their targets-- according to the Nature article:
"High-affinity binding (the affinity constant Ka = 3-6 10X^8, similar to affinity-matured antibodies) is directed towards species- or strain-specific cell-wall carbohydrates".
So creating a broad-specificity phage would be like making a broad-specifity antibody-- kind of a contradiction in terms.
>So you eat bateria to kill a virus.
No, actually you get an injection with a purified enzyme from a type of virus, that kills the bacteria. Anthrax is a bacterial species.
>(I thought viruses merged with your DNA...).
That's only retroviruses. In this case the target of the virus is the bacteria, so if it were going to integrate into any DNA it would be the bacterial DNA. But, this bacteriophage is not a retrovirus, and only the purified lysin protein is being used, not the whole virus.
Jeez, when they said "dated picture" I thought they meant Rosalind Franklin's X-ray diffraction image, shown at:
Recycling: it's not just for newspapers and soda bottles anymore...
"Bring out yer dead!"
>There is [sic] only 115 streches [ebi.ac.uk] of DNA that are known in public databases Yes, but >100 of the DNA sequences that come up in that search are for endogenous retroviruses or microsatellite DNA (repetitive junk), which don't tell you anything about the mammoth genes' coding sequences... The few actual mammoth sequences that are known include the 12S RNA and cytochrome B (J Mol Evol 1998 Mar;46(3):314-26) which are mitochondrial genes. It makes sense that the researchers have managed to get these sorts of things (mitochondrial genes, repetitive elements) since they would be present at multiple copies per cell, but learning about ordinary single copy genes is much more difficult. . Of course, knowing about the mammoth's DNA doesn't really matter for these scientists since they are trying to use frozen mammoth sperm.
Why not clone the world's best search and rescue dog, instead of someone's family pet ? Simple, that's what the people with the funding chose to do. Same thing in this case. That, and as far as I know, there aren't any frozen Dodos around waiting to be used for donor cells/DNA.
>The cloning process involves putting DNA from the mammoth into an Asian elephant's egg that has been stripped of elephant genes. >So even though an elephant would give birth, the baby would be a mammoth, not a hybrid
Well, the two teams have the same goal, but this technique would produce an actual clone (well, ok, except that it would have Asian elephant mitochondrial DNA). The Japanese team in the news now is actually trying to make a hybrid,
by "impregnating an Indian elephant with mammoth sperm ".
Actually, the first time I heard W use the phrase "Office of Homeland Security" I was like, "So what exactly is the department of _Defense_ for then?"