Virus Killers

Cecil's Columns/Staff Reports
21

I have created an account for limited access on that server.

Username: kyberneticist
Password: everyone

The following are limited info links on prions:
http://www.sciencemag.org/cgi/content/short/287/5453/661
http://www.sciencemag.org/cgi/content/short/287/5453/562b
http://www.sciencemag.org/content/vol287/issue5453/twis.shtml#287/5453/545l

As it notes this does not prove mammalian prions are soley responsible, but it is strongly suggestive.

22

Kyberneticist -

The cited articles do indeed demonstrate that prions are sufficient when added to yeast cells to induce heritable changes in cell behavior.

But, the most plausible way of their doing so is to alter the expression of host cell DNA which includes a gene already included in the genome which when transcribed, codes for the prion molecule itself.

In other words, a prion can only infect a cell which already has the DNA coding for the prion. The prion simply turns on expression of this gene; as long prion molecules distribute themselves into each daughter cell, the daughter cells will continue to express that gene & behave just as a newly infected cell.

What remains to be seen is whether there is genomic DNA which has the correct sequence to code for the prions. To the best of my knowledge, this as yet has not been demonstrated or refuted.

This DNA could be either inherited from many rungs down the evolutionary tree, or could have come from a latent virus which infected a distant ancestor & then became incorporated into germ cell (Pre-ova or sperm) lines so that all progeny from this ancestor carry the gene, and are simply waiting for the prion to arrive & turn it on.

Sue from El Paso
Siamese Attack Puppet - Texas

Experience is what you get when you didn’t get what you wanted.

23

Jois - I’m going to try to work with your analogy. If it gets silly, it’s all your fault. :wink:

If you construct REPAIR so that it’s a self-starting robot, you don’t have to park it in Spot 15. (If the correct copy of the gene came with it’s promoter regions intact) But that is not necessarily any easier than building a robot which requires external stimulation (The promoter at spot 15) and then making sure it goes to spot 15, and only spot 15. Getting turned on by another gene’s promoter could lead to low blood sugars; not getting turned on by its own promoter could cause high blood sugars.

Finding keys with which to OPEN DNA is not difficult; finding the right key among millions to OPEN Spot 15 is very difficult with todays technology.

THe BUS technology is pretty well worked out; it just doesn’t steer well. In the aftermath of a death (or deaths?) associated with these bus drop-offs, however, additional information about what exactly happens to the bus after delivering REPAIR is being sought.

You don’t really have to remove the defective part.

Hope this helps.

  • Sue
24

Actually, the most successful viruses are those which don’t destroy the host until the host has had plenty of opportunity to spread it around.

Lassa & Ebola viruses kill their hosts too fast to infect many of patients form one victim. Influenza, herpes, & HIV can infect hundreds of people before the host dies or is killed off by the virus.

  • Sue
25

Majormd said

yeah this link and a news spot I saw today seem to have an explanation.

26

Huh - that was NOT the story I was trying to link to… the HIV contamination story came out after I posted.

I’m sorry the msn.com links morphed. There were supposed to be three stories covering various angles of gene therapy problems.

I seriously doubt if HIV was responsible, pweetman; the progression was just too fast. Also, the possible HIV tainted viral cultures occurred at St. Judes (Memphis) & Baylor (Houston) while the 18 year old who dies was being treated under a totally different protocol by a University of Pennsylvania team.

Also the HIV contamination allegations are:

  1. There is no documentation that viral cultures used were tested for HIV (or Hep C) contamination before gene transfers were performed.
  2. Tests on the cultures shows the presence of DNA from HIV and from HCV. This does not mean there is intact virus particles or even intact “chromosomes” from these viruses. In fact - since HIV (and, I believe HCV) are RNA viruses, their genetic material is RNA, not DNA, so the presence of viral DNA in the culture is not the smoking gun it might appear. Any research lab is going to have all kinds of DNA fragments in the air; in fact in all experiments using polymerase chain reaction (PCR) techniques include steps to destroy DNA in the test materials to avoid such contamination. None of the patients thus far have tested positive for HIV*; many have died, but since the gene therapy was being used to treat a very lethal form of childhood cancer, the deaths were not unexpected.
  • because the patient’s immune systems are highly suppressed due to chemotherapy, lack of antibodies does NOT equate to lack of HIV infection - additional tests are pending, however.

This IS an inexcusable lapse on appropriate quality control in a very new way of treating diseases. Additional oversight is apparently needed. I hope the current backlash turns out to be overkill, and that further work on these projects can ultimately proceed once more.

Sue from El Paso
Siamese Attack Puppet - Texas

Experience is what you get when you didn’t get what you wanted.

27

PS - let’s see if these links work better:
http://www.msnbc.com/news/365651.asp http://www.msnbc.com/news/364359.asp http://www.msnbc.com/news/343802.asp http://www.msnbc.com/news/341863.asp

  • Sue
28

Try this bit from the listed 3-4 cites.

What I’ve been trying to learn is the sequence of events in using a virus to implant correct DNA and where the problematic areas are. So far it looks like the problematic areas are everywhere.

Thanks to all for your help. Feel free to toss in anything else you think would be helpful.

Jois

Oh, I’m gonna keep using these #%@&* codes 'til I get 'em right.

29

I’ve started a separate prion topic in great debates. It may not be that long, but the links above have expired and there’s a lot more on the net that can be read for free. The topic will be simply PRIONS - is there such a thing?

30

Good idea, Sunbear, but toss it back into General Questions (i.e. start over) if it gets too weird in GD.

Are you driving with your eyes open or are you using The Force? - A. Foley