Fig. 2.

A: schematic of sinus fluid fill-volume measurement setup, incorporating constant-flow infusion pump delivering perfluorocarbon liquid directly into nasal sinuses of guinea pig, with pressure transducer in delivery line to monitor pressure development and release, with achievement of sinus filling. Amp, direct current (DC) amplifier feeding DC pressure signal to personal computer from pressure transducer (P) via analog-to-digital conversion board, with digital readout from data display and acquisition program, shown on computer monitor. B: screenshots of typical pressure tracings recorded during the sinus fluid fill-volume experiments. Left: tracing of pressure development and release in guinea pig with no administration of ragweed pollen (RWP); elapsed time of pressure development was ~42 s, indicating a long duration of sinus filling, consistent with a high volume in uncongested sinuses. Right: tracing of pressure development and release in guinea pig treated with intranasal (i.n.) administration of RWP; elapsed time of pressure development was <10 s, indicating a brief duration of sinus filling, consistent with a low volume in congested sinuses. Note the difference in time scale at the bottom of each tracing.