11.   When used with longstanding therapies like AZT, experts said, it can repress the AIDS virus below detectable levels for months in a substantial number of patients.

12.   The researchers were disappointed that the virus returned to detectable levels in all the vaccinated volunteers.

13.   These combinations can drive the virus below detectable levels, but in about half of patients, the virus returns within a year.

14.   When treatment pushes the virus below detectable levels and keeps it there, doctors feel fairly certain that patients will stay healthy for several years.

15.   In many people, they have been found to suppress levels of HIV to below detectable levels.

16.   At the other end of the scale, four of the non-organic soups had no detectable levels of the precious compound at all.