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DR. FREDRICKSON: Relative to the polyoma experiments. 
DR. TOOZE : Oh, the risk-assessment one? Well, whether the recombinant 
molecules are infectious per se will be probably the end of February, be- 
cause that simply involves taking this DNA and sprinkling it on some cells 
and seeing what happens. But then if you are going to feed it in E. coli to 
mice, then you have to really wait for the natural lives of those mice, so 
that means 18 months. 
We are going to specifically issue actually a press release saying that 
as soon as we go into the animal stage of the experiment, there will be a 
total blackout on all information until all the data is collected, because 
this is the sort of experiment which is open to misinterpretation. 
DR. FREDRICKSON: Mr. Helms. 
MR. HELMS: Will enough be done, let us say, by the end of February, to 
be informative to Dr. Helinski's group; or is it too early a stage? I am 
just not enough of a scientist to know how far you have to take this for it 
to be useful for the revision of these Guidelines. 
DR. FREDRICKSON: Dr. Tooze , what do you think? 
DR. TOOZE: I think that this particularly is just one experiment, and 
assessing risk in this field is a manifold business, and this will just be 
one experiment. Many other sorts of risk assessment experiments can go on 
in parallel. The increase in confidence it will give one in the Guidelines 
either way is not going to be that great. But that is true of almost any 
risk-assessment experiment. 
DR. FREDRICKSON: Dr. Sinsheimer has a question. 
DR. SINSHEIMER: John, I have to ask a couple of questions, and I don't 
know that much about animal viruses. I am frequently struck by the anthropo 
morphic character of the discussion here as we suggest that polyoma work is 
safe because polyoma doesn't replicate in human cells. What is the host 
range of polyoma besides rodents? What do we know about other animals? 
DR. TOOZE: I think that as far as we know in nature it is only in mice 
isn't it, but Wally knows a great deal more about that than I do. You might 
ask him. 
DR. FREDRICKSON: Would you like Dr. Rowe to answer that? 
DR. ROWE: In nature, antibodies have never been found in any species 
except mice. In the laboratory it will enter cells and transform in a 
number of small rodents, but does not replicate. In rats it replicates 
very inefficiently, but it does make some virus. In human cells, a few 
human cell lines at very high multiplicity, you can get some antigen induced 
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