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The cell membrane is one of the most important structures to understanding life and disease, but it is poorly understood. A new math model may help change that  (Source: University of Helsinki)

By understanding how the AIDS virus's membrane behaves, new drugs and methods can be developed to fight the disease.  (Source: Jeff Johnson)
New models provide insight into cell biology not possible with pure experimentation

Ever wonder exactly how a cell, the basis of all living things works?  So do researchers.  While scientists have been able to derive a great deal of information about cellular components, what they do and some of the chemical processes that they carry out is poorly understood.

Among the biggest puzzles is the cell membrane.  The cell membrane is made up of molecules which are charged components on one side and have uncharged hydrocarbon tails on the other side.  These molecules, called lipids, form a bi-layer due to the tails wanting to congregate together to avoid the polar water molecules inside and outside the cell.  However, cell membranes can also merge with each other, which seems counterintuitive as this would require the polar head groups, which would seem to repel each other, to be attracted to each other.

UCLA Henry Samueli School of Engineering and Applied Science researcher William Klug and colleagues from the California Institute of Technology and the Whitehead Institute for Biomedical Research in Massachusetts think they have found a way to partially explain this and other membrane phenomena via a new math model.  Their new model provides a way of predicting the forces which create and maintain certain organelle membranes.

Why is this research so exciting?  Those same membranes are found in everything from human cells to certain viruses such as the AIDS virus.  By understanding better how compounds interact with molecules from molecular physics standpoint, new drugs to fight diseases such as AIDS and cancer may be developed.

Professor Klug explains, "The study is exciting because it provides a roadmap for ways we can do predictive computational science.  The mathematical model is able to provide us with a quantitative understanding of the physics of cells that is essentially impossible to obtain directly by experiment."

One of the important behaviors it predicts is membrane deformation and stretching under certain conditions.  Paul Wiggins, a fellow at the Whitehead Institute, explains this phenomena, stating, "When you step on a scale, a small spring in the scale defines how heavy you are or what force is being applied to the scale.  Similarly, with membranes, springs or forces cause them to bend. In a sense, we wanted to see if we could play the same game with the organelles of a cell — to take the observed structure and see if we can predict what forces are applied to give rise to the structure and essentially hold the structure together."

Far from pure theory, the researchers' work was largely based on and validated by experimentation.  The team used a device known as optical tweezers, a tiny laser beam to attract or repel parts of the cell, changing the forces exerted on the membrane.  This validated the underlying structure of the team's model and allowed them to tweak its parameters for better accuracy.

Mr. Wiggins explains how the new model may give insight into factors that damage cells, an important cause of disease in humans.  He states, "When cells undergo oxygen damage, that usually leads to a change in the structure of the mitochondria — the specialized organelles often referred to as the powerhouses of cells.  There is a close link between the ability of the mitochondria to function and its structure. By relating structure to force, we can uncover the crucial factors that lead to the change in the structure of the mitochondria and other organelles as well."

Furthermore, the model will help to simulate the process of virus budding.  When membrane bound viruses, such as the AIDS virus, infect a cell they reproduce their DNA.  Then they cannibalize the cell's membrane to make membranes for these "baby" viruses, eventually destroying the cell.

Professor Klug describes, "The forces that lead to the process of budding are essentially unknown.  Researchers have looked at the image data of HIV in different stages of budding to try to understand the forces that lead up to it. If we can eventually understand what those forces are, we might be able to come up with a way to disrupt the viral assembly process. And that's a different strategy than what is being done today to treat retroviruses and HIV in particular."

Their study can be found here in the journal Proceedings of the National Academy of Sciences (PNAS).

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By jadeskye on 12/9/2008 1:00:05 PM , Rating: 5
Aids is an absolutely horrific diesease.

Anything that can advance it's treatment is a quantum leap in medicine in my opinion.

RE: Aids.
By chmilz on 12/9/2008 1:06:51 PM , Rating: 5
$180,000 shot directly into the bloodstream is the cure. At least according to South Park.

Seriously though, a cure needs to be found, entire countries are crippled by AIDS.

RE: Aids.
By Raidin on 12/9/2008 1:16:43 PM , Rating: 2
Or an very high dose of Vitamin C.

Oh wait, that's Polio.

RE: Aids.
By quiksilvr on 12/9/2008 6:16:00 PM , Rating: 2
I have one question that I've having trouble finding the answer to:if men spread AIDS to men/women via semen, how do women spread AIDS?

RE: Aids.
By Ordr on 12/9/2008 6:26:47 PM , Rating: 2

RE: Aids.
By amanojaku on 12/9/2008 6:33:18 PM , Rating: 4
Snowballs. ;-)

Blood, semen, vaginal fluid, pre-ejaculate, or breast milk are fluids that transmit HIV, the cause of AIDS.

RE: Aids.
By Ordr on 12/9/2008 8:00:13 PM , Rating: 3
Your wink is extremely off-putting.

RE: Aids.
By quiksilvr on 12/9/2008 9:06:11 PM , Rating: 2
So the vaginal fluid goes up the man's urethra? Damn...

RE: Aids.
By Ordr on 12/9/2008 9:21:31 PM , Rating: 2
Only if you're good all year.
Merry Christmas.

RE: Aids.
By amanojaku on 12/9/2008 9:33:49 PM , Rating: 5
No, vaginal fluid does NOT go up the urethra. The urethral sphincter regulates the flow of urine from out of the bladder and keeps anything from going in. The HIV pathogen is only 120nm in diameter; this is smaller than blood cells and can easily slip through tears in the skin or pores. Tears on the penis and vagina happen all the time if you're having sex; the rougher or more frequent the sex the larger and more numerous the tears.

RE: Aids.
By James Wood Carter on 12/10/2008 8:06:46 PM , Rating: 3
many ways of transmission including blood transfusions (rare these days), contaminated needles vaginal fluids. Though if you get infected with HIV-1 (many serotypes, 1 is the most studied one) you can take anti-virals that block the viral entry. Usually that can reduce risk of HIV establishing infection. Also HIV cannot be curred, but if antivirals are taken responsibly HIV can be kept under control ! there are many drugs out there to repress HIV-1 and tehre are cases of people not dying from it even after many years

RE: Aids.
By UNHchabo on 12/9/2008 2:41:35 PM , Rating: 2
"AIDS? Wow, that's so... retro."

Parker and Stone are right in that episode: nobody cares about AIDS anymore, but it's still a very serious disease.

(just a small article nitpick: HIV is a virus, AIDS is not)

RE: Aids.
By SilthDraeth on 12/9/2008 3:35:25 PM , Rating: 2
I don't consider it a nitpick, considering there are tons of immune deficiencies known, and several things that cause Acquired Immune Deficiency (AKA AIDS).

HIV is just one cause of AIDS, and to that, the least is known. So the headline to this article is even more patently false. If anything he should of put HIV in the headline.

Don't worry, I just quote Wikipedia, because it is a simple look, and a cursory definition of what Acquired immunodeficiency is, there are plenty of other resources to read. But like most arm chair doctors, lawyers, and politicians on this site, I don't expect any real research.

"Acquired immunodeficiency

Immune deficiency may also be the result of particular external processes or diseases; the resultant state is called "secondary" or "acquired" immunodeficiency. Common causes for secondary immunodeficiency are malnutrition, aging and particular medications (e.g. chemotherapy, disease-modifying antirheumatic drugs, immunosuppressive drugs after organ transplants, glucocorticoids).

Many specific diseases directly or indirectly impair the immune system. This includes many types of cancer, particularly those of the bone marrow and blood cells (leukemia, lymphoma, multiple myeloma), and certain chronic infections. Immunodeficiency is also the hallmark of acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV). HIV indirectly attacks the immune system."

RE: Aids.
By James Wood Carter on 12/10/2008 8:12:26 PM , Rating: 2
Not quite .. immunodeficiencies are common cytopathic effects of pathogens, afterall its one of their key ways for establishing chronic infection. HIV-1 is nasty, it makes you prone to disease (a cold can kill you) that otherwise would not in non immuno compromised individuals, also certain pathogens are continually kept controlled byt the immune system .. so AIDS would make it more likely that these pathogens disbalance the equilibrium between pathogen-host. so HIV isn't as nitpick as it might sound

RE: Aids.
By Samus on 12/10/2008 3:50:19 AM , Rating: 2
it's just retro because we've been fighting it for 30 years. polio took us 20 years to vaccinate and it was a much simpler virus

RE: Aids.
By PrinceGaz on 12/9/2008 10:51:27 PM , Rating: 2
There are retro-viral drugs available which can keep HIV at bay pretty much indefinitely. In other words the infected person still has HIV but never progresses beyond that to develop AIDS (which is where it has a detrimental effect on them).

So in one sense, the cure is already there, but it is a cure developing countries cannot afford. The $180,000 shot directly into the bloodstream probably isn't far off the total cost of the existing retro-viral drugs for an HIV positive patient in a western country where treatment is paid for by the national health system.

A cure will no doubt be found eventually one way or another, provided the drug companies continue to fund research into finding cures rather than relying on the current treatments which have to be taken (and therefore bought) for the rest of your life.

HIV is not necessarily a killer disease even if untreated; it is known that a few percent of the population have a genetic trait which prevents the virus from ever taking hold in their bodies. That is to be expected really, as I'm sure viruses have in the past devestated the population but there must always have been a small number of people with the right genetic traits to be resistant, and they survived. If this wasn't the case, then all higher forms of life would have been wiped out long before now by some particularly virulent viruses.

Nature knows best and the best thing to do is let her choose who goes on to breed the next generation. Those alive today who have become infected should be treated with the available drugs to keep symptoms at bay, but for the good of the human species in the long-run, until a total cure is found, anyone not naturally resistant to HIV should be sterilised so that they can not pass on their genes (as they would have been unable to do so anyway without the treatment).

Harsh? Maybe. But I believe any treatments which keep people alive who would otherwise have died from infections should be accompanied with a sterilisation as that is what would have happened with natural selection. Similarly, infertility treatments that allow women to have babies they otherwise could not are a serious threat to the long term viability of the human-race as a whole, as it will inevitably result in an ever greater reliance on artifical pregnancies.

If you can not naturally have a baby, or medical intervention for any reason has saved you from dying, then I feel it is only right that you should not be able to have a child, for the good of humanity as a whole. Natural selection is the reason we are as we are today. Once we ignore natural selection and let everyone breed, including people who would have died if not for intensive medical treatment, the genetic quality of the human species will deteriorate quickly. If unchecked, we could all but wipe ourselves out in a couple of hundred years as the population as a whole becomes increasingly infertile and more dependent on artificial solutions.

RE: Aids.
By dani31 on 12/10/2008 4:01:33 AM , Rating: 2
We've been cheating natural selection eversince the first caveman put an animal skin on not to die of cold.

It is obvious that we are unable to survive out of the artificial environment we created, because it has become too complex.

But one thing I agree, we should not treat infertility.

RE: Aids.
By zsdersw on 12/10/2008 6:57:45 AM , Rating: 2
Yes, we've always been looking for the easy and pain-free way out of the problems we face. Rather than adapting to the environment, we shield ourselves from or alter it.

Despite what the Dow commercials say, we don't exist in harmony with nature, we constantly isolate ourselves from it or work to alter it.. whichever is more convenient. Only for brief and fleeting moments in time do we find nature suitable for us to leave it alone and come anywhere close to "harmony" with it.

Pure isolation from nature could be considered harmonic, but not opportunistic cycles of isolation and attempted alteration.

RE: Aids.
By FaceMaster on 12/9/2008 1:29:09 PM , Rating: 2
Really? I wouldn't have known.

RE: Aids.
By Gzus666 on 12/9/2008 2:32:36 PM , Rating: 2
AIDS not Aids, it isn't a word it is an acronym (or abbreviation or initialism depending who you speak to).

Also, I was under the impression AIDS was an awesome fun time that everyone loved, who would have known? /sarcasm

RE: Aids.
By cparka23 on 12/9/2008 10:16:14 PM , Rating: 3
Thank you for pointing this out, lest we lynch Jared and his aides a second time

I'm happy to see that they're so positive.
By Ordr on 12/9/2008 1:41:45 PM , Rating: 4
*snare drum*

RE: I'm happy to see that they're so positive.
By Etsp on 12/9/2008 3:15:31 PM , Rating: 2
They aren't just positive, they're HIV positive!

By DASQ on 12/9/2008 5:50:56 PM , Rating: 3
Thanks for trodding on the joke. Jerk.

By BruceLeet on 12/9/2008 3:18:00 PM , Rating: 2
it goes.. Bass drum;Hi-Hat;Snare;Tom;Crash cymbal

To each their own conclusion...
By SilthDraeth on 12/9/08, Rating: 0
By SilthDraeth on 12/9/2008 2:06:27 PM , Rating: 2

That is a follow up article due to criticisms many here my express.

Also what Masher states is true as well.

By MozeeToby on 12/9/2008 3:49:30 PM , Rating: 3
everything he wrote started making sense to me in a way that the currently accepted model did not. I didn’t have anywhere near all the information, but my instincts told me that what he said seemed to fit.

This is the definition of bad science. She has decided based on her 'gut instincts' that one belief is true, then over the next 10 years sought out material to support that belief.

RE: To each their own conclusion...
By clovell on 12/9/2008 4:05:42 PM , Rating: 3
This is garbage. This woman claims 10 years of experience, despite only having a PhD. for no more than 4 years. In the same article, she points to a causal link between Protease Inhibitors and HIV-deaths, while blasting the body of evidence for a causal link between HIV and AIDS.

Utterly ridiculous - A mathematician who cannot construct an arguement that is not self-defeating requires more formal education before presuming to be taken seriously. She should do the millions of people around the globe who are suffering from HIV a favor and think rationally before opening her mouth again.

As for your title, conclusions are merited by evidence and data. When this woman can critique the data or *gasp* provide her own, her conclusions may be considered as something other than anectdotal drivel.

I know how we can find the cure!
By encryptkeeper on 12/9/2008 2:28:35 PM , Rating: 3
Just feature AIDS as the disease on an episode of House M.D.. House will have it figured out in 50 minutes.

By seraphim1982 on 12/9/2008 3:26:05 PM , Rating: 2
Man Made Virus... mark my words =P

By BruceLeet on 12/10/2008 6:10:49 PM , Rating: 2
I'll see your House M.D. and raise you WebMD

Nothing to do with AIDS
By masher2 on 12/9/2008 1:52:24 PM , Rating: 5
Despite the article headline, this research has nothing to do with AIDS in particular-- though it eventually may lead to a better understanding of how HIV or any membrane-penetrating virus works.

The force of the cell
By Proxes on 12/9/2008 4:47:00 PM , Rating: 2
"What are mitochondria?"

RE: The force of the cell
By DASQ on 12/9/2008 5:52:22 PM , Rating: 3
... midiclorians?

The real problem
By Queonda on 12/9/2008 4:23:36 PM , Rating: 2
Fornication and needles. Why haven't we figured that one out?

RE: The real problem
By wordsworm on 12/10/2008 3:12:30 AM , Rating: 1
Everything to do with life and living has risk. Everything from the prick from a rose thorn to air has the ability to carry killer viruses, bacteria, or fungi. This old Bible thumping mentality is retarded. Not that you're one of them, but some folks say that it's God's disease for the sinners and that AIDS is just a punishment/warning.

If you follow the Bible, and something bad happens, God's testing you. If it's someone who doesn't follow the Bible or goes against it, then God's punishing them.

Switzerland, thankfully, just passed a resolution to continue with government controlled heroin injection sites. That's one way to combat the problem, as it drastically reduces the risk of spreading HIV. Using condoms is another way of drastically reducing the spread. Unfortunately, even most advanced nations don't care about their own people.

RE: The real problem
By zsdersw on 12/10/2008 6:49:03 AM , Rating: 1
Fornication and needles, huh? Well, celibate and sober people die or are seriously injured all the time.. from such things as accidents, dietary choices, and the deliberately performed acts of others.

The point? Don't take life so seriously... you won't make it out alive.

By William Gaatjes on 12/9/2008 4:47:55 PM , Rating: 2
Once you know the exact way physics work you can solve everything. This is fantastic progress. Every disease is no different then an impurity in a metal causing it to be weaker then it should be.

Review on AIDS
By drvitor on 12/9/2008 7:30:06 PM , Rating: 2
A bit of information on AIDS may be useful. Visit this link for a review made of 15 questions and answers:

"I modded down, down, down, and the flames went higher." -- Sven Olsen

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