We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm c...We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.展开更多
DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this...DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this study, models of diffuse brain injury were established in Sprague-Dawley rats with the vertical impact method. DI-3n-butylphthalide at 80 and 160 mg/kg was given via intraperitoneal injection immediately after diffuse brain injury. Ultrastructural changes in the cerebral cortex were observed using electron microscopy. Cerebral blood flow was measured by laser Doppler flowmetry, vascular density was marked by tannic acid-ferric chloride staining, vascular permeability was es- timated by the Evans blue method, brain water content was measured using the dry-wet method, and rat behavior was measured by motor function and sensory function tests. At 6, 24, 48, and 72 hours after administration of dl-3n-butylphthalide, reduced cerebral ultrastructure damage, in- creased vascular density and cerebral blood flow, and improved motor and sensory functions were observed. Our findings demonstrate that dl-3n-butylphthalide may have protective effects against diffuse brain injury by ameliorating microcirculation disorder and reducing blood-brain barrier dam- age and cerebral edema.展开更多
目的观察慢性脑低灌模型大鼠脑血流量和脑血管周细胞覆盖率。方法选择健康雄性成年SD大鼠30只,双侧颈动脉结扎法制备慢性脑低灌注模型。随机分为假手术组和模型组,每组15只。术后4周观察筑巢和贮食等行为学,利用激光散斑成像检测脑血流...目的观察慢性脑低灌模型大鼠脑血流量和脑血管周细胞覆盖率。方法选择健康雄性成年SD大鼠30只,双侧颈动脉结扎法制备慢性脑低灌注模型。随机分为假手术组和模型组,每组15只。术后4周观察筑巢和贮食等行为学,利用激光散斑成像检测脑血流量,透射电镜观察脑血管周细胞覆盖率,荧光定量PCR和免疫荧光检测血管内皮生长因子(vascular endothelial growth factor,VEGF)mRNA和蛋白表达水平。结果与假手术组比较,模型组大鼠筑巢评分明显降低,剩余贮食明显增多,差异有统计学意义(P<0.05)。与假手术组比较,模型组大鼠大脑皮质脑血流量明显减少[(73.83±8.57)%vs 100%,P<0.05],毛细血管周细胞覆盖率明显降低[(60.67±7.73)%vs(76.33±7.63)%,P<0.05]。与假手术组比较,模型组大鼠大脑皮质VEGF mRNA和蛋白表达明显降低(0.66±0.13 vs 1.00±0.00,78.00±14.01 vs 288.83±53.99,P<0.05)。结论双侧颈动脉结扎法模型大鼠脑血流量和脑血管周细胞覆盖率降低有助于进一步揭示脑小血管病的发病机制。展开更多
文摘We present numerical simulations of blood flow through a brain vascular aneurysm with an artificial stent using Smoothed Particle Hydrodynamics (SPH). The aim of this work is to analyze how the flow into an aneurysm changes using different stent configurations. The initial conditions for the simulations were constructed from angiographic images of a real patient with an aneurysm. The wall shear stresses, pressure and highest velocity within the artery, and other particular quantities are calculated which are of medical specific interest. The numerical simulations of the cerebral circulation help doctors to determine if the patient’s own vascular anatomy has the conditions to allow arterial stenting by endovascular method before the surgery or even evaluate the effect of different stent structure and materials. The results show that the flow downstream the aneurysm is highly modified by the stent configuration and that the best choice for reducing the flow in the aneurysm is to use a completely extended Endeavor stent.
基金supported by the grants from Hebei Province Science and Technology Ministry,No.20276102DKey Project of Hebei Province Education Ministry,No.ZD2010106
文摘DI-3n-butyiphthalide can effectively treat cerebral ischemia; however, the mechanisms underlying the effects of dl-3n-butylphthalide on microcirculation disorders following diffuse brain injury remain unclear. In this study, models of diffuse brain injury were established in Sprague-Dawley rats with the vertical impact method. DI-3n-butylphthalide at 80 and 160 mg/kg was given via intraperitoneal injection immediately after diffuse brain injury. Ultrastructural changes in the cerebral cortex were observed using electron microscopy. Cerebral blood flow was measured by laser Doppler flowmetry, vascular density was marked by tannic acid-ferric chloride staining, vascular permeability was es- timated by the Evans blue method, brain water content was measured using the dry-wet method, and rat behavior was measured by motor function and sensory function tests. At 6, 24, 48, and 72 hours after administration of dl-3n-butylphthalide, reduced cerebral ultrastructure damage, in- creased vascular density and cerebral blood flow, and improved motor and sensory functions were observed. Our findings demonstrate that dl-3n-butylphthalide may have protective effects against diffuse brain injury by ameliorating microcirculation disorder and reducing blood-brain barrier dam- age and cerebral edema.
文摘目的观察慢性脑低灌模型大鼠脑血流量和脑血管周细胞覆盖率。方法选择健康雄性成年SD大鼠30只,双侧颈动脉结扎法制备慢性脑低灌注模型。随机分为假手术组和模型组,每组15只。术后4周观察筑巢和贮食等行为学,利用激光散斑成像检测脑血流量,透射电镜观察脑血管周细胞覆盖率,荧光定量PCR和免疫荧光检测血管内皮生长因子(vascular endothelial growth factor,VEGF)mRNA和蛋白表达水平。结果与假手术组比较,模型组大鼠筑巢评分明显降低,剩余贮食明显增多,差异有统计学意义(P<0.05)。与假手术组比较,模型组大鼠大脑皮质脑血流量明显减少[(73.83±8.57)%vs 100%,P<0.05],毛细血管周细胞覆盖率明显降低[(60.67±7.73)%vs(76.33±7.63)%,P<0.05]。与假手术组比较,模型组大鼠大脑皮质VEGF mRNA和蛋白表达明显降低(0.66±0.13 vs 1.00±0.00,78.00±14.01 vs 288.83±53.99,P<0.05)。结论双侧颈动脉结扎法模型大鼠脑血流量和脑血管周细胞覆盖率降低有助于进一步揭示脑小血管病的发病机制。
