PGN induces platelet activation in challenged baboons. (A) PGN challenge induces progressive thrombocytopenia in baboons in a dose-dependent manner. Data representation and statistical analysis are consistent with Figure 1. (B) Representative micrographs of Giemsa-stained serial blood smears from high-dose PGN group highlighting circulating platelet aggregates (arrows) in challenged baboons. Images were acquired on an upright Nikon Eclipse E800M microscope equipped with an Omax high-speed digital camera using the Omax ToupView software. (C) Immunofluorescence analysis of platelet activation in peripheral tissues of high-dose PGN-challenged primates at end point. Conformational changes in active GPIIbIIIa integrin were detected using the PAC-1 monoclonal followed by fluorescein isothiocyanate (FITC)-labeled donkey anti-mouse secondary (Jackson ImmunoResearch). DAPI was used for nuclear counterstaining. Confocal images were acquired on a Nikon Eclipse TE2000-U inverted microscope equipped with a Nikon C1 scanning head using EZ-C1 software. Representative micrographs from kidneys (left) and lung (right) sections from high-dose PGN-challenged baboons are shown. Scale bars represent 20 µm.