a035  0223  17 Jul 82
PM-Tainted Mice,320
Genetically Impure Mice May Affect Cancer Research
By MICHAEL C. BUELOW
Associated Press Writer
    MADISON, Wis. (AP) - Hundreds of previous cancer experiments and
continuing research worldwide could be invalidated because of a
genetic impurity found in a strain of laboratory mice, scientists say.
    ''This is a major contamination problem of almost inestimable
consequence,'' said Robert Auerbach, a zoologist at the University of
Wisconsin. He cited examples of commercial and academic research
projects that were unsuccessful, possibly because of the inconsistent
response of the impure mice.
    Brenda Kahan, another university zoologist, said a nine-month
experiment on mice purchased in January 1981 showed they were not the
genetically pure BALB-c strain, important for cancer research and
other experiments because of their susceptibility to cancer.
    Tests by university researchers and University of Minnesota
immunologists on a second batch ordered in November 1981 confirmed the
impurities, Ms. Kahan said Friday.
    ''It would be as if you bought a chemical that wasn't what was
contained in the bottle,'' said Auerbach, who reported the findings
with Ms. Kahn in Science magazine. ''The damage to research must be
formidable.''
    They said the mice were shipped from Charles River Breeding
Laboratories Inc. in Wilmington, Mass. - the world's largest breeder
of laboratory animals.
    Ms. Kahan said she had no way to estimate how long the company had
unknowingly been shipping the imperfect mice or how many shipments had
been made.
    The company said it became aware of the problem when contacted by
the university in January.
    ''To the best of my knowledge there is no problem now,'' said Wayne
Bolen, a company customer service manager. ''I can't say for sure
there wasn't a problem prior to January. Once we were notified of the
complaint, however, we immediately began testing.''
    
ap-ny-07-17 0523EDT
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a243  1600  16 Jul 82
AM-Tainted Mice,560
Genetic Impurity Could Invalidate Much Research, Scientists Say
By HELEN L. MITTERNIGHT
Associated Press Writer
    MADISON, Wis. (AP) - Researchers have discovered a genetic impurity
in a special strain of laboratory mice which could invalidate
hundreds of important cancer experiments, University of Wisconsin
scientists said Friday.
    Mice genetically different from the inbred strain needed for cancer
and other biomedical research have been shipped by the world's
largest breeder of laboratory animals, Charles River Breeding
Laboratories Inc. of Wilmington, Mass., they said.
    In a report in Science magazine, the scientists said the discovery
of the tainted mice is a potential ''catastrophe of almost inestimable
consequence'' in the world of biological research.
    ''It would be as if you bought a chemical that wasn't what was
contained in the bottle,'' University of Wisconsin zoologist Robert
Auerbach said. ''The damage to research must be formidable.''
    Brenda Kahan, associate scientist in zoology at the university, said
it was impossible to evaluate the damage done to research worldwide
by the impure shipments of so-called BALB-c mice.
    ''This particular strain is perhaps the most frequently used strain
of inbred mouse. I don't think we have any knowledge yet of the
problem,'' she said.
    Ms. Kahan said the error could mean the repeat of many experiments
in biomedical research. The BALB-c strain is valued because it is
particularly susceptible to cancer.
    Auerbach said that if the genetic makeup in the rodents differs from
the pure strain expected, the results of the experiment could be
misinterpreted or impossible to interpret accurately.
    Dr. Melvin Balk, laboratory chief for Charles River, said the
breeder has been genetically monitoring the mice since October 1981.
Until then, the integrity of inbred strains was monitored mostly
through breeding records, he said in a reply also published in
Science.
    ''That won't totally eliminate errors as long as there are people
involved, but it will minimalize the error until they are practically
non-existent,'' Balk said. He said that although he was not certain
that a problem exists with the mice, it was possible.
    ''A white mouse is basically a white mouse,'' he said. ''So, the
boxes could have been mislabeled. Or, an escaped animal could have
bred with one of the wrong mice.''
    Only mice from two of Charles River's nine breeding locations are
involved, he said.
    The mice, with their reddish eyes and white fur, seem like identical
twins, which is, in effect, what they are. The validity of research
using the mice depends on the fact that the inbred mice are virtual
clones of - almost genetically identical to - each other and would
have the same immune systems and the same reactions to drugs.
    Ms. Kahan said she discovered the impurities a year ago when she and
associates spent nine months trying to create a special breed of
mouse by breeding other mice with the mice she assumed were pure. When
she did not get the expected results, she investigated further and
found that the mice from Charles River were impure.
    Similar tests run by scientists at the University of Minnesota
confirmed the Wisconsin results, she said.
    ''These people could have saved everybody a lot of time and grief if
they would have just gotten on the phone (to us) as soon as they saw
something,'' Balk said.
    Ms. Kahan said she waited until she received another shipment from
the breeder in November 1981 to make sure that it was not just one
shipment that had been tainted.
    
ap-ny-07-16 1900EDT
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