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The molecular cage holds the xenon, while the target unit (orange) allows it to selectively bind to the desired target molecule.  (Source: Berkeley Lab and UC Berkeley)

When the molecule finds its target, the cryptophan cage starts to convert polarized xenon gas to non-polarized xenon. The proess is temperature dependent, which can improve the accuracy of the detection.  (Source: Berkeley Lab and UC Berkeley)

The team that developed the new technology includes team leader Leif Schröder (left) with Monica Smith, who holds a probe housing a phantom target, and Tyler Meldrum, holding a model of a biosensor's cryptophane cage  (Source: Berkeley Lab and UC Berkeley)
Peeking inside the human body just got a little bit easier

Some very complex, but very important research breakthroughs have recently taken place at the labs of Alexander Pines and David Wemmer at Berkeley Lab and UC Berkeley.  The new breakthroughs revolve around the process of magnetic resonance imaging (MRI).  MRIs are valuable diagnostic tools, helping to reveal detailed information on neurological, musculoskeletal, cardiovascular, and oncological structure and health.  This in turn allows doctors to diagnose tumors and various other maladies.

The main problem with MRIs is that they’re slow, force the patient to lie still, and lack resolution.  The alternative is to take a biopsy of the possibly affected tissue, but many chemical tests must be done to analyze it.  Now a new method in essence lets a highly accurate MRI, thousands of times more precise to be conducted on biopsies, allowing individual molecules to be identified, and largely eliminating the need for multiple tests.

Tradition MRI devices rely on Nuclear Magnetic Resonance (NMR) imaging; a process by which RF radiation is sent, setting molecules spinning due to their odd number of protons.  Depending on the nearby structures, their spin will be altered.  RF radiation is subsequently emitted from the spinning molecule, revealing if it spins "up" or "down".  By measuring the number spinning up versus down, the nearby structures attached can be determined.  In MRIs the spin of the molecules is traditionally enhanced used a magnetic field.

Typically, MRIs measure spin from hydrogen atoms, an abundant element in the human body, which is largely composed of hydrocarbons.  Traditional biopsy methods typically rely on chemical indicators, which change color when they detect a specific target molecule.

The new method combines NMR/MRI technology with biopsy analysis.  The key is to use xenon gas molecules and a special organic molecular cage which holds them.   The molecule is composed of a cage which holds xenon molecules, an intermediate organic section, and a ligand (part of the molecule which bonds to other stuff) at its end.  The ligand ensures that the molecule only bonds to a specific target.

The molecules are injected along with polarized xenon gas into the sample.  When the cage molecules find the target of their ligand, they bond to it.  The cage then begins to depolarize xenon.  This depolarized xenon is then picked up by MRI devices.  This specialized type of Magnetic Resonance Imaging is dubbed Hyper-CEST for hyperpolarized xenon chemical-exchange saturation transfer.

The rate can also be temperature controlled, to improve the process.  Also using multiple cage designs can improve results.  The end result is a much higher accuracy version of MRI/biopsy processes.  Team member Tyler Meldrum, of the Materials Sciences Division describes these benefits stating, "Slight differences in cage composition, involving only a carbon atom or two, affect the frequency of the signal from the xenon and produce distinct peaks in the NMR spectrum.  If we design different cages for different xenon frequencies, we can put them all in at once and, by selectively tuning the rf pulses, see peaks at the frequencies corresponding to each kind of cage.

While this technology will likely take a while to get to market, it will likely provide a valuable diagnostic tool.  The researchers have solved half the problem -- the detection molecule -- now the real challenge that remains is cataloguing ligands that can bind selectively to the plethora of molecules produced when stuff goes right or wrong in the human body. 

This new diagnostic tool, while very promising, like many new promising drug delivery techniques, relies on the development of target molecules which can detect cancer cells or other items of interest.  The problem won't be solved overnight, but by slow and steady research.  This is why projects like Folding At Home remain so valuable to the medical community.



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RE: Yea but...
By dever on 5/9/2008 2:21:31 PM , Rating: -1
I am absolutely amazed at how many people still hold on to some mystic belief that the principles of socialism really will work in some utopia, if we could only elect just the right saint to manage such a dictatorship. This would have been forgivable 100 years ago, but the mountain of evidence suggesting just the opposite is overwhelming.

Unfortunately, humans are fallible, both civilians and politicians. And, it's been proven over and over, that the only way to compensate for this imperfect nature in economics is to allow each party to freely and willingly enter into agreements. This system is commonly referred to as a free market, and is what the founders of the US considered to be one of the essential human liberties. Fortunately, it also happens to be a huge boon to the financial well-being those who are privileged enough to be part of such a system.


RE: Yea but...
By winterspan on 5/9/2008 5:56:07 PM , Rating: 3
What you say is correct, but not relevant to what he said. No one is talking about throwing out the constitution and capitalism and going to communism/socialism. Government structures all remain intact, and the free market remains intact.
The only thing that changes is that the healthcare system shifts from a private, for-profit 'oligarchy' run by large corporations to a government organized non-profit. Thus, the HUGE profits going to the corporate/elite coffers gets redirected back into the 'pot'. With proper leadership and organization, and the delegation of the actual healthcare practice to private companies, We could definitely have a win-win private+public partnership. And I am NOT talking about an imaginary Utopia, but a well-functioning healthcare system that reduces overall costs for the middle class (read: The actual 'normal' people in the USA).

I'm wondering if all the readers here know that nearly every other developed 'western' country in the world either has a national health care system or is in the process of building one. Then again, In most of those counties, the ELECTORATE IS ACTUALLY IN CONTROL OF THE COUNTRY, AND NOT THE OLIGARCHY.


RE: Yea but...
By djc208 on 5/12/2008 6:53:13 AM , Rating: 2
quote:
With proper leadership and organization, and the delegation of the actual healthcare practice to private companies


See you had a decent point until there, then you just veered off into a fantasy world.

Problem is, like the tax system, while there are easier and more efficient ways to do the same thing, there's also too much money wrapped up in the way it's currently done. No group of politicians has the testicular fortitude to interefere in that kind of money flow and the jobs that go with it.


RE: Yea but...
By dever on 5/13/2008 2:34:15 PM , Rating: 2
quote:
the free market remains intact... shifts to a government organized non-profit
Nationalization (government control) of private industry is the basis of socialism. You can't be serious in arguing that when an entire industry is controlled by the government the "free market remains intact?" Is this what public schools are teaching now?

quote:
nearly every other developed 'western' country in the world either has a national health care system or is in the process of building one
Yes, and America still has the BEST healthcare system... I'd like to retain that distinction. Many of the richest politicians from those other countries come to America for treatment when their life is on the line. Recent example was a Canadian Senator who came to California for her treatment of breast cancer. Of course, most of her middle-class constituents do not have that option.

The study of prioritizing the allocation of scarce resources (economics) has for 200 years found that the most efficient way to do this is the free market. Every interference (controls, regulations, etc.) in the end, increases the cost to the consumer. Increase costs means reduced demand (only the wealthiest can afford to go outside of the government system). Or, if government tries to combat this with "price caps" the result is reduced supply.


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