Writing and Using Learning Objectives.

Learning objectives (LOs) are used to communicate the purpose of instruction. Done well, they convey the expectations that the instructor-and by extension, the academic field-has in terms of what students should know and be able to do after completing a course of study. As a result, they help students better understand course activities and increase student performance on assessments. LOs also serve as the foundation of course design, as they help structure classroom practices and define the focus of assessments. Understanding the research can improve and refine instructor and student use of LOs. This essay describes an online, evidence-based teaching guide published by CBE-Life Sciences Education (LSE) at http://lse.ascb.org/learning-objectives. The guide contains condensed summaries of key research findings organized by recommendations for writing and using LOs, summaries of and links to research articles and other resources, and actionable advice in the form of a checklist for instructors. In addition to describing key features of the guide, we also identify areas that warrant further empirical studies.

Ultrasound imaging of acute cardiac transplant rejection with microbubbles targeted to intercellular adhesion molecule-1.

BACKGROUND: Noninvasive techniques for detecting acute cardiac transplant rejection are limited. We hypothesized that ultrasound contrast microbubbles targeted to the endothelial cell (EC) inflammatory marker intercellular adhesion molecule-1 (ICAM-1) would selectively bind to rejecting versus nonrejecting myocardium and that myocardial contrast echocardiography can therefore detect acute rejection. METHODS AND RESULTS: Lipid-based microbubbles were conjugated to anti-rat ICAM-1 (MBICAM) or isotype control antibody (MBControl). In vitro MBICAM adhesion to cultured rat ECs, as assessed in a parallel plate flow apparatus, was greater to inflammatory versus normal ECs (11+/-3 versus 3+/-2 microbubbles/EC, P<0.005). In vivo abdominal heterotopic heart transplantation was performed in rats (rejection group: Brown Norway to Lewis strain; control group: Lewis to Lewis or Brown Norway to Brown Norway). Triggered myocardial contrast echocardiography was performed during intravenous MBICAM or MBControl (2.5x10(6)) injection on postoperative day 5. Myocardial videointensity from adhered MBICAM was significantly higher in rejecting (n=8) versus control (n=7) rats (10+/-4 versus 1+/-4 U, P=0.01). Postmortem histology showed normal myocardium in control rats, whereas allograft myocardium demonstrated grade III to IV rejection and strong immunohistochemical ICAM-1 staining. CONCLUSIONS: Preferential adherence of ICAM-1-targeted microbubbles to rejecting versus nonrejecting rat cardiac transplant myocardium can be detected ultrasonically. Targeted microbubbles may thus offer a noninvasive ultrasound imaging technique for the detection of acute cardiac transplant rejection and other processes characterized by endothelial dysfunction.

Targeted in vivo labeling of receptors for vascular endothelial growth factor: approach to identification of ischemic tissue.

BACKGROUND: A method for identifying tissue experiencing hypoxic stress due to atherosclerotic vascular disease would be clinically useful. Vascular endothelial growth factor-121 (VEGF121) is an angiogenic protein secreted in response to hypoxia that binds to VEGF receptors overexpressed by ischemic microvasculature. We tested the hypothesis that VEGF receptors could serve as markers for ischemic tissue and hence provide a target for imaging such tissue with radiolabeled human VEGF121. METHODS AND RESULTS: A rabbit model of unilateral hindlimb ischemia was created by femoral artery excision (n=14). Control rabbits (n=5) underwent identical surgery without femoral excision. On postoperative day 10, rabbits were intravenously administered 100 microCi of 111In-labeled recombinant human VEGF121, and biodistribution studies and planar imaging were conducted at 3, 24, and 48 hours. On postmortem gamma counting, there was greater accumulation of 111In-labeled VEGF121 in ischemic than in control tissue (P<0.02). Differential uptake of isotope by ischemic muscle was not seen in rabbits injected with 125I-labeled human serum albumin (n=6). Radioactivity imaged in hindlimb regions of interest was significantly higher in ischemic muscle than in sham-operated and contralateral nonoperated hindlimb at 3 hours (P<0.02). Immunohistochemical staining confirmed upregulation of VEGF receptors in ischemic skeletal muscle. CONCLUSIONS: Identification of the ischemic state via targeted radiolabeling of hypoxia-induced angiogenic receptors is possible. This approach could be useful for monitoring the efficacy of revascularization strategies such as therapeutic angiogenesis.