Ursula I Tuor1, Qinbo Deng2, Dave Rushforth3, Taduesz Foniok4, Min Qiao5. 1. Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada; Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada. Electronic address: utuor@ucalgary.ca. 2. Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada. Electronic address: dengqinbo@gmail.com. 3. Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada. Electronic address: drushfor@ucalgary.ca. 4. Experimental Imaging Centre, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada. Electronic address: tfoniok@ucalgary.ca. 5. Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, AB T2N 4N1, Canada. Electronic address: mqiao@ucalgary.ca.
Abstract
BACKGROUND: Transient ischemic attack, minor stroke and stroke recurrence need improved treatment but lack animal models for research. The aim was to modify photothrombosis methods thereby producing both a minor stroke (with adjacent mild damage) or a minor recurrent stroke. NEW METHOD: A minor stroke, as detected using magnetic resonance imaging and histology, was produced using a low intensity beam of white light with a bright centre, a low dose of Rose Bengal and a short 5min illumination of thinned skull. A recurrent minor stroke was produced by repeating the procedure two days later except the cortical mask was positioned 1.5mm posteriorly. RESULTS: The minor photothrombosis procedure produced a small superficial infarct surrounded by a region of scattered necrosis detected histologically. Marked hyperintensities in diffusion weighted and T2 images identified the infarct. Peri-infarct regions with modest T2 increases corresponded to regions of scattered cell death. A recurrent minor photothrombosis produced additional damage in regions with overlapping mild injury. COMPARISON WITH EXISTING METHODS: Previous photothrombosis methods usually produce large cortical infarcts with little penumbra. The current method produces small infarcts with diffuse mild peri-infarct ischemic injury that can be diagnosed using T2 imaging. CONCLUSIONS: The modified photothrombotic procedure will produce a minor stroke consisting of a small infarct in a region with marked diffusion and T2 hyperintensities and a peri-infarct region of selective necrosis with modest T2 changes. Minor recurrent stroke is readily produced but imaging is key for assessing size and location of each insult.
BACKGROUND: Transient ischemic attack, minor stroke and stroke recurrence need improved treatment but lack animal models for research. The aim was to modify photothrombosis methods thereby producing both a minor stroke (with adjacent mild damage) or a minor recurrent stroke. NEW METHOD: A minor stroke, as detected using magnetic resonance imaging and histology, was produced using a low intensity beam of white light with a bright centre, a low dose of Rose Bengal and a short 5min illumination of thinned skull. A recurrent minor stroke was produced by repeating the procedure two days later except the cortical mask was positioned 1.5mm posteriorly. RESULTS: The minor photothrombosis procedure produced a small superficial infarct surrounded by a region of scattered necrosis detected histologically. Marked hyperintensities in diffusion weighted and T2 images identified the infarct. Peri-infarct regions with modest T2 increases corresponded to regions of scattered cell death. A recurrent minor photothrombosis produced additional damage in regions with overlapping mild injury. COMPARISON WITH EXISTING METHODS: Previous photothrombosis methods usually produce large cortical infarcts with little penumbra. The current method produces small infarcts with diffuse mild peri-infarct ischemic injury that can be diagnosed using T2 imaging. CONCLUSIONS: The modified photothrombotic procedure will produce a minor stroke consisting of a small infarct in a region with marked diffusion and T2 hyperintensities and a peri-infarct region of selective necrosis with modest T2 changes. Minor recurrent stroke is readily produced but imaging is key for assessing size and location of each insult.
Authors: Anil Zechariah; Cam Ha T Tran; Bjorn O Hald; Shaun L Sandow; Maria Sancho; Michelle Sun Mi Kim; Sergio Fabris; Ursula I Tuor; Grant R J Gordon; Donald G Welsh Journal: Arterioscler Thromb Vasc Biol Date: 2019-12-12 Impact factor: 8.311