Pharmacokinetics studies of chimerictrans-sialidases. Mice intravenously inoculated with 100 pmoles (about 10 ug) of the indicated protein, were bled at the indicated days after injection and measured for remnant trans-sialidase activity in serum samples. Data are expressed as the mean ± standard deviation (SD) (n = 3 animals). Values recorded 30 minutes after injection are indicated as day 0 values and were taken as 100%trans-sialidase activity. One out of two experiments with similar results is shown. Asterisks (*) denote significant differences (P < .05) to TS-SAPA protein.