1.   Researchers have found that stress can be monitored by measuring levels of the hormone cortisol in saliva.

2.   The rules deal with measuring levels of pollutants in Venezuelan and Brazilian gasoline imported for sale in pollution-choked northeastern U.S. cities.

3.   Trophoblastic cells secrete hCG, and by measuring levels of hCG in the blood, doctors can monitor the course of disease.

4.   Experts say the new test, which involves measuring levels of cholesterol components called apolipoproteins, will fine-tune traditional cholesterol testing.

5.   The researchers compared the two approaches by measuring levels of a blood protein called prostate-specific antigen for years after treatment.

6.   The researchers found that measuring levels of apoB, attached to the bad LDL cholesterol, predicted fatal heart attacks more accurately than simply measuring LDL.