Quantitation of the 31/32-nt saliva Y4-RNA fragment by RT-PCR. The values connected to a black dot denote mean values, and each of the other dots represents a value of one of the independent saliva RNA samples. (A, B) Saliva was collected at noon and 1:30 p.m. from the examinees E1 and E4 on 3 and 4 different days, respectively, and each saliva RNA (0.1 ng) was subjected to RT-PCR. A meal was not taken between noon and 1:30 p.m. in (A), and a meal was taken soon after saliva collection at noon in (B). (C) Saliva was collected at noon and 1:30 p.m. from E1 on 3 different days, and each saliva RNA (0.1 ng) was subjected to RT-PCR. A meal was taken soon after saliva collection at noon, and aspirin (660 mg) was taken soon after having the meal.