Background and Purpose-Age is the most important risk factor for ischemic stroke. Recent experiments evidenced an age-associated rarefaction of the native collateral vasculature. The purpose of this study was to assess in what way age and arteriogenesis influence cortical perfusion and recovery of hemodynamic impairment in aged and young C57/BL6 mice. Methods-After model establishment of chronic cerebral hypoperfusion in the C57/BL6 strain, sustained hemodynamic impairment was induced by permanent unilateral internal carotid artery occlusion in animals aged 4 to 6 weeks, 12 weeks, and 18 months. Functional and morphological outcome was assessed by laser speckle imaging before and during acetazolamide challenge on Days 0, 3, 7, and 14 and latex/carbon black angiography and immunohistochemistry on Day 21. Results-Although internal carotid artery occlusion did not result in a reduction of baseline perfusion, it led to significant hemodynamic impairment in all age groups. Furthermore, baseline perfusion in sham and cerebrovascular reactivity after internal carotid artery occlusion were significantly lower in animals aged 18 months (468±57 Flux; 20.8%±17%) compared with mice aged 4 to 6 weeks (568±120
Purpose: Receptor tyrosine kinase AXL (RTK-AXL) is regarded as suitable target in glioma therapy. Here we evaluate the anti-tumoral effect of small molecule inhibitor BMS-777607 targeting RTK-AXL in a preclinical glioma model and provide evidence that RTK-AXL is expressed and phosphorylated in primary and recurrent glioblastoma multiforme (GBM).Experimental design: We studied the impact of BMS-777607 targeting RTK-AXL in GBM models in vitro and in vivo utilizing glioma cells SF126 and U118MG. Impact on proliferation, apoptosis and angiogenesis was investigated by immunohistochemistry (IHC) and functional assays in vitro and in vivo. Tumor growth was assessed with MRI. Human GBM tissue was analyzed in terms of RTK-AXL phosphorylation by immunoprecipitation and immunohistochemistry.Results: BMS-777607 displayed various anti-cancer effects dependent on increased apoptosis, decreased proliferation and migration in vitro and ex vivo in SF126 and U118 GBM cells. In vivo we observed a 56% tumor volume reduction in SF126 xenografts and remission in U118MG xenografts of more than 91%. The tube formation assay confirmed the anti-angiogenic effect of BMS-777607, which became also apparent in tumor xenografts. IHC of human GBM tissue localized phosphorylated RTK-AXL in hypercellular tumor regions, the migratory front of tumor cells in pseudopalisades, and in vascular proliferates within the tumor. We further proved RTK-AXL phosphorylation in primary and recurrent disease state.Conclusion: Collectively, these data strongly suggest that targeting RTK-AXL with BMS-777607 could represent a novel and potent regimen for the treatment of primary and recurrent GBM.
Randomized trials of thienopyridines in patients with vascular disease demonstrate that thienopyridines are effective in reducing vascular events when compared with placebo/control or aspirin, as well as when used in combination with aspirin in patients undergoing intracoronary stent implantation. The CURE trial is a large international study to determine if acute and long-term treatment with the combination of clopidogrel and aspirin is superior to aspirin alone in patients with acute coronary syndrome.
Background and Purpose-Direct extracranial-intracranial bypass surgery for treatment of cerebral hemodynamic compromise remains hindered by complications but alternative simple and safe indirect revascularization procedures, such as an encephalomyosynangiosis (EMS), lack hemodynamic efficiency. Here, the myoblast-mediated transfer of angiogenic genes presents an approach for induction of therapeutic collateralization. In this study, we tested the effect of myoblast-mediated delivery of vascular endothelial growth factor-A (VEGF) to the muscle/brain interface of an EMS in a model of chronic cerebral hypoperfusion. Methods-Permanent unilateral internal carotid artery-occlusion was performed in adult C57/BL6 mice with or without (no EMS) surgical grafting of an EMS followed by implantation of monoclonal mouse myoblasts expressing either VEGF 164 or an empty vector (EV). Cerebral hemodynamic impairment, transpial collateralization, angiogenesis, mural cell investment, microvascular permeability, and cortical infarction after ipsilateral stroke were assessed by real-time laser speckle blood flow imaging, 2-and 3-dimensional immunofluorescence and MRI. Results-VEGF-expressing myoblasts improved hemodynamic rescue by day 14 (no EMS 37±21%, EV 42±9%, VEGF 48±12%;P<0.05 for VEGF versus no EMS and versus EV), together with the EMS take rate (VEGF 60%, EV 18.2%; P<0.05) and angiogenesis of mature cortical microvessels below the EMS (P<0.05 for VEGF versus EV). Importantly, functional and morphological results were paralleled by a 25% reduction of cortical infarction after experimental stroke on the side of the EMS.
Conclusions-Myoblast-mediated
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