ABSTRACT
INTRODUCTION: Hypothermic machine perfusion, an organ preservation modality, involves flow of chilled preservation fluid through an allograft's vasculature. This study describes a simple, reproducible, human model that allows for interrogation of flow effects during ex vivo organ perfusion. MATERIALS AND METHODS: Gonadal veins from deceased human renal allografts were subjected to either static cold storage or hypothermic machine perfusion for up to 24 hours. Caspase-3, Krüppel-like factor 2 expression and electron microscopic analysis were compared between 'flow' and 'no-flow' conditions, with living donor gonadal vein sections serving as negative controls. RESULTS: The increase in caspase-3 expression was less pronounced for hypothermic machine-perfused veins compared with static cold storage (median-fold increase 1.2 vs 2.3; P < 0.05). Transmission electron microscopy provided ultrastructural corroboration of endothelial cell apoptosis in static cold storage conditions. For static cold storage preserved veins, Krüppel-like factor 2 expression diminished in a time-dependent manner between baseline and 12 hours (P < 0.05) but was abrogated and reversed by hypothermic machine perfusion (P < 0.05). CONCLUSIONS: Our methodology is a simple, reproducible and successful model of ex vivo perfusion in the context of human organ preservation. To demonstrate the model's utility, we establish that two widely used markers of endothelial health (caspase-3 and Krüppel-like factor 2) differ between the flow and no-flow conditions of the two predominant kidney preservation modalities. These findings suggest that ex vivo perfusion may mediate the induction of a biochemically favourable endothelial niche which may contribute tohypothermic machine perfusion's association with improved renal transplantation outcomes.
Subject(s)
Kidney Transplantation/methods , Kidney/blood supply , Models, Biological , Organ Preservation Solutions/pharmacokinetics , Organ Preservation/methods , Apoptosis , Biomarkers/metabolism , Cadaver , Caspase 3/metabolism , Cold Temperature , Endothelium, Vascular/metabolism , Humans , Kidney/metabolism , Kidney/ultrastructure , Kruppel-Like Transcription Factors/metabolism , Microscopy, Electron , Perfusion/methods , Veins/metabolism , Veins/ultrastructureSubject(s)
Knee Joint/surgery , Pain/surgery , Female , Femur/surgery , Humans , Male , Methods , Patella/surgery , Retrospective StudiesABSTRACT
Since 1976 a series of surveys of flight instructors and students in general and commercial aviation, and the Royal Australian Air Force, has indicated several common problems in flight instruction. These problems have provided a focus for instructor education programs described in this paper. Professional preparation of instructions in areas such as educational psychology (learning and memory, motivation, and skill acquisition) met with the approval of the participants, but no detectable change in instructional methods resulted. It is concluded that a commitment to the professionalization of flight instruction must come from within the occupational group.
Subject(s)
Aviation , Teaching , Australia , Inservice Training , Psychology, EducationalSubject(s)
Carbon , Knee Joint/surgery , Ligaments, Articular/surgery , Prostheses and Implants , Carbon Fiber , Humans , Joint Instability/surgery , MaleABSTRACT
Samples of Air Force fighter pilots, trainee commercial pilots, and males drawn from the general community completed the Edwards Personality Preference Schedule (EPPS). Four significant effects were found for individual sub-scales; three (Achievement, Affiliation, and Nurturance) identifying air force fighter pilots. Commercial pilot trainees scored significantly less than the community sample on Succorance and Nurturance. The data suggest that the EPPS consists of several related personality dimensions. One of these, "sociability," discriminated fighter pilots from the general community.
