title: Flow cytometric assays to detect platelet activation and aggregation in device-implanted calves.
abstract: Cardiovascular device development often relies upon large-animal models to assess blood biocompatibility prior to initiating clinical trials. Unfortunately, the amount of information gleaned from such trials is limited by simple assays that do not take full advantage of immunotechnological advances that increasingly are applied in clinical studies. Thus we have developed and tested new flow cytometric techniques for measuring circulating activated bovine platelets and platelet microaggregates. Monoclonal antibodies (MAbs) raised against both activated and quiescent bovine platelets were incubated with control and PMA-or ADP-stimulated whole blood. Selected MAbs detected activated bovine platelets and platelet microaggregates in vitro with flow cytometry. Five calves implanted with one of two designs of nonpulsatile ventricular-assist devices (VADs) were followed with these assays prior to and during VAD implantation. Circulating activated bovine platelets and microaggregates increased after implantation in all animals and, alternatively, remained elevated or returned toward preimplant levels. Platelet activation percentages as detected temporally by three MAbs were correlated with one another, and platelet activation was correlated with microaggregate formation. In summary, these new methods for the sensitive measurement of circulating activated bovine platelets and microaggregates may provide valuable information for the development and assessment of future cardiovascular device designs.
authors.affiliation: Department of Surgery, University of Pittsburgh, Pennsylvania 15213, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Baker
authors.forename: W C
authors.initials: WC
authors.lastname: Davis
authors.forename: J
authors.initials: J
authors.lastname: Autieri
authors.forename: M J
authors.initials: MJ
authors.lastname: Watach
authors.forename: K
authors.initials: K
authors.lastname: Yamazaki
authors.forename: P
authors.initials: P
authors.lastname: Litwak
authors.forename: W R
authors.initials: WR
authors.lastname: Wagner
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015703:Antigens, CD / Q000276:immunology; D016824:Antigens, Human Platelet / Q000276:immunology; D000954:Antigens, Surface / Q000276:immunology; D001672:Biocompatible Materials; D001792:Blood Platelets / Q000187:drug effects / Q000276:immunology; D002417:Cattle; D003429:Cross Reactions; D005434:Flow Cytometry; D006353:Heart-Assist Devices; D006801:Humans; D008858:Microscopy, Phase-Contrast; D015539:Platelet Activation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D013045:Species Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D016824:Antigens, Human Platelet; D000954:Antigens, Surface; D001672:Biocompatible Materials; D000244:Adenosine Diphosphate; D013755:Tetradecanoylphorbol Acetate