Experimental acute XXXX in baboons.

@entity64 @entity1396 @entity1269 @entity2500 @entity3474 @entity406 @entity1188 @entity661 @entity715
To study the effects of antithrombotic therapy in experimental @entity64 , we have characterized a @entity3474 model of @entity715 . In this model an inflatable silastic balloon cuff has been implanted by transorbital approach around the right middle cerebral artery (MCA), proximal to the take-off of the lenticulostriate arteries (LSA). Inflation of the balloon for 3 hours in six animals produced a stereotypic @entity64 characterized by @entity1269 . An @entity1188 volume of 3.2 +/- 1.5 cm3 in the ipsilateral corpus striatum was documented by computerized tomographic (CT) scanning at 10 days following @entity64 induction and 3.9 +/- 1.9 cm3 (n = 4) at 14 days by morphometric neuropathologic determinations of brain specimens fixed in situ by pressure-perfusion with 10% buffered @entity406 . Immediate pressure-perfusion fixation following deflation of the balloon was performed in 16 additional animals given Evans blue dye intravenously prior to the 3 hour @entity2500 . Light microscopy and transmission electron microscopy consistently confirmed the presence of @entity715 material occluding microcirculatory branches of the right LSA in the region of Evans blue stain, but not those of the contralateral corpus striatum. When autologous 111In-platelets were infused intravenously in four animals from the above group prior to the transient 3 hour occlusion of the right MCA, gamma scintillation camera imaging of each perfused-fixed whole brain demonstrated the presence of a single residual focus of 111In-platelet activity involving only the Evans blue-stained right corpus striatum. Focal right hemispheric activity was equivalent to 0.55 +/- 0.49 ml of whole blood, and the occlusion score derived from histologic examination of the microcirculation of the Evans blue-stained corpus striatum averaged 34.8 +/- 2.8. Similar 111In-platelet imaging and histologic scoring experiments carried out in four animals pretreated with the antithrombotic combination heparin and @entity1396 showed marked reduction of both 111In-platelet activity (0.01 +/- 0.03 ml vs. 0.55 +/- 0.49 ml; p less than 0.01) and @entity715 occlusion of the microcirculation (10.8 +/- 7.4 units vs. 34.8 +/- 2.8 units; p less than 0.01) in the right corpus striatum following 3 hours of @entity2500 . In separate control experiments 111In-labeled autologous platelets were infused after the 3 hour period of @entity2500 and @entity661 in two animals; no focus of 111In-platelet activity was demonstrated in fixed whole brain.(ABSTRACT TRUNCATED AT 400 WORDS)
