21.   Doctors cautioned that the tests were not conclusive, but point to a relatively low risk of passing infertility directly from generation to generation.

22.   The doctors cautioned that exercise does not guarantee a person immunity from the disease.

23.   The doctors caution that the disease is unpredictable, the newspaper reported Sunday.

24.   The doctor cautioned, however, that Zanardi still is grappling with the situation.