New treatment for CAD

[bumab]

I was thinking about possible new solutions to the common problem of clogged arteries. As we all know, most older folk have large plaque deposits in their arteries, especially around the heart. These deposits form thrombuses (throbii?) which protrude into the artieries, attracting platelets and various other things, eventually leading to heart attacks.

 

My background is ecology, so I was thinking about how milfoil is often controlled in lakes. Tetraploid fish are introduced which eat the milfoil, however since the tetraploidy prevents them from viable reproduction, there's no invasive species problem- they die off in one generation.

 

So- back to the arteries. If one could devlope a strain of bacteria which eat plaque (it's a fatty deposit, so it's probably possible), you could simply introduce the critters and have them reduce the levels of plaque, while avoiding surgury or the stints, which don't help that much in the long run. The hard part is controlling them past that first generation. I was thinking two possible solutions. Genetic "adjustment" to remove genes resonsible for spindle formation or some other thing that would prevent the bacteria from splitting, thus avoiding reproduction. Or, genetic modification to make the strain especially weak to anti-biotics, and kill them off with a massive IV dose every 6 hours or so, then introduce more. Various methods could be used to insure only modified bacteria are introduced, like flourescent tagging to the introduced DNA, then simply grab the ones that glow for introduction.

 

Obviously, some difficulties left to work out, but it seems like a good new direction for medicine to go. why look for nanobots wheh there's millions of nature made ones available for use right now?

 

what do you think- pie in the sky or possibility?

[Fishteacher73]

One other solution would be to remove a gene that produces one of the essential amino acids or protiens, and have the patient dosed with these to alow the bacteria to consume what it needs for survival, then once the job is done simply cut off the suplimentation and the bacteria die off in a short time by not being able to metabolize any nutrients.

[bumab]

Do you think the fundamental idea is viable?

[Fishteacher73]

While I think that it is theoretically possible, bacteria REALLY like to mutate and trade genes. Any genetic "fail-safes" would have a reasonable chance of either being randomly mutated or trading genetic material through conjugation with other fully functional bacteria to become fully functional bacteria.

 

One question to ponder, is any plaque a good thing? Could we essentially introduce a symbiont that would reach a reasonable balance that would not be harmful to humans? We have dozens of bacteria that live perminantly in our GI tract. It could be slightly risky introducing a bacteria into the bloodstream (Risk of infection from other bacteria). The big key here would be developing a bacteria that the body would not attack.

[bumab]

The big key here would be developing a bacteria that the body would not attack.

 

Yes and no- I was thinking that the bodies natural defenses would be valuable, they would be one more check against the growth of the bacteria. It's playing with fire, I wasn't looking for a long term symbiont, but rather a short term fix (but a much more complete fix then we currently have). Longer term symbiotic behavior, while cool, would be incredibly difficult to engineer.

 

On that note, dentists recently dvloped a new mouth flora that doesn't produce tooth decaying by products. I can't find the link right now, I ran accross it while looking for information for the CAD idea. Anyway, the new flora permenently replaces the older, traditional mouth bacteria, and you no longer have to wrory about tooth decay

[Fishteacher73]

Is this set of bacteria just more "fit" and out competes the original population? Does each individual have the same grouping of oral bacteria, or is it an individualized fauna? If not individualized, is it regionaliized? Perhaps another forensic tool.....

[bumab]

Is this set of bacteria just more "fit" and out competes the original population? Does each individual have the same grouping of oral bacteria, or is it an individualized fauna? If not individualized, is it regionaliized? Perhaps another forensic tool.....

 

Apparently, they just kill off the old population with drugs, introduce the new population, and allow the bigger population advantage to exclude any survivors from the origional mouth. Most likely, given a while, the genes would be diluted and a new batch would need to go in, Im not sure, the study didn't address that. It's basically an identical bacteria, with a single gene (the lactic acid gene? i think that's the acid involved in tooth decay) being removed.

[Fishteacher73]

Ahhh... So it is an altered version of the original set. I was thinking that they replaced the populations with a different bacteria that was more viable in the oral cavity and it simply out competed the initial bacteria.

[bumab]

This is a different study (just a summary- http://www.newscientist.com/article.ns?id=dn1941), most likely a follow-up to the one I saw (because it's a little more sophisticated). In this, they use a strain that kills off the normal bacteria and is modified to not secrete acid.

[Biochemist]

As we all know, most older folk have large plaque deposits in their arteries, especially around the heart. These deposits form thrombuses (throbii?) which protrude into the artieries, attracting platelets and various other things, eventually leading to heart attacks..... If one could devlope a strain of bacteria which eat plaque (it's a fatty deposit, so it's probably possible), you could simply introduce the critters and have them reduce the levels of plaque, while avoiding surgury or the stints, which don't help that much in the long run.

 

FYI- the clogs are not usually thrombi, although they are sometimes. Usually it is just the plaque. When the thrombus is the culprit, it is usually on top of a plaque that started the whole mess.

 

I think you get an "A" for innovation here, but there are a couple of interesting problems.

1) I think you couldn't give a large enough innoculum if the bacteria didn't divide. We would probalby have to depend on division to get a colony built on the plaque to digest it. This suggests that we would need to set some sort of replication timer (i.e., stop division at 1000 generations) or to make the little beggars really sensitive to a particular antibiotic. And FT73's point that the litte rascals trade genes around via episomes is a troublesome worry as well.

2) I am also combing by brain to figure out whether digesting the cholesterol would cause problems other places, and I bet it does. Cholesterol is a mandatory substrate/precursor for lots of hormones (like all of the sex hormones and cortisol as I recall, but I could be wrong on that). If we ate all of it up, it might cause a lot of ugly unintended consequences.

 

Clever idea, though.