Tumor cell proliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme(GBM). The purpose of this study was to determine the effect of radiation on...Tumor cell proliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme(GBM). The purpose of this study was to determine the effect of radiation on the growth characteristics of primary human GBM developed in a nude rat. Primary GBM cells grown from explanted GBM tissues were implanted orthotopically in nude rats. Tumor growth was confirmed by magnetic resonance imaging on day 77(baseline) after implantation. The rats underwent irradiation to a dose of 50 Gy delivered subcuratively on day 84 postimplantation(n = 8), or underwent no radiation(n = 8). Brain tissues were obtained on day 112(nonirradiated) or day 133(irradiated). Immunohistochemistry was performed to determine tumor cell proliferation(Ki-67) and to assess the expression of infiltration marker(matrix metalloproteinase-2, MMP-2) and cell migration marker(CD44). Tumor neovascularization was assessed by microvessel density using von-Willebrand factor(vWF) staining. Magnetic resonance imaging showed well-developed, infiltrative tumors in 11 weeks postimplantation. The proportion of Ki-67-positive cells in tumors undergoing radiation was(71 ± 15)% compared with(25 ± 12)% in the nonirradiated group(P = 0.02). The number of MMP-2-positive areas and proportion of CD44-positive cells were also high in tumors receiving radiation, indicating great invasion and infiltration. Microvessel density analysis did not show a significant difference between nonirradiated and irradiated tumors. Taken together, we found that subcurative radiation significantly increased proliferation, invasion, and migration of primary GBM. Our study provides insights into possible mechanisms of treatment resistance following radiation therapy for GBM.展开更多
A workshop on‘Climate Change and its Impact on Water Resources’was organised by Centre for Earth and Space Science,Uni-versity of Hyderabad,Hyderabad,India during 8th to 10th November 2010.The impact of climate chan...A workshop on‘Climate Change and its Impact on Water Resources’was organised by Centre for Earth and Space Science,Uni-versity of Hyderabad,Hyderabad,India during 8th to 10th November 2010.The impact of climate change on freshwater systems and water resources needs to be quantified and modeled for better management.Projected changes in the frequency and severity of extreme climate events have significant consequence on agriculture and food production.A novel idea has been proposed in the model presented in this article,which calls for an integrated approach from various disciplines to create an awareness on climate change effects on agriculture and environment.展开更多
鲁尔德巴格勒（Rhourde el Baguel）油田位于古达米斯（Ghadmes）盆地内，是阿尔及利亚最大油田之一，从海平面以下2300—3070m深度寒武系砂岩采油。该构造重新解释为与两条逆断层有关的挤压褶皱，这两条逆断层切割以前的一条正断层并...鲁尔德巴格勒（Rhourde el Baguel）油田位于古达米斯（Ghadmes）盆地内，是阿尔及利亚最大油田之一，从海平面以下2300—3070m深度寒武系砂岩采油。该构造重新解释为与两条逆断层有关的挤压褶皱，这两条逆断层切割以前的一条正断层并使之变形。构造是在三个主要变形幕期间形成的：①三叠纪至侏罗纪里阿斯期拉张作用，结果形成有大幅度断距的正断层；②中侏罗世里阿斯期盐层流动，结果形成本单元内几个低幅度构造；③早白垩世时期奥地利运动产生挤压作用，结果形成一种基底卷入断层传播褶皱。修改的构造模型阐明了在构造西翼上几口深井中观察的各单元复杂的断层样式和异常厚度变化。此模型已经应用于某些现有深井侧钻进入油田范围内位置，并且优化油田内新钻井位置。展开更多
基金supported by grants from the National Institutes of Health (NIH) [No. K25CA129173 (MMA), R01CA122031 (ASA), and 1R01CA160216 (ASA)]
文摘Tumor cell proliferation, infiltration, migration, and neovascularization are known causes of treatment resistance in glioblastoma multiforme(GBM). The purpose of this study was to determine the effect of radiation on the growth characteristics of primary human GBM developed in a nude rat. Primary GBM cells grown from explanted GBM tissues were implanted orthotopically in nude rats. Tumor growth was confirmed by magnetic resonance imaging on day 77(baseline) after implantation. The rats underwent irradiation to a dose of 50 Gy delivered subcuratively on day 84 postimplantation(n = 8), or underwent no radiation(n = 8). Brain tissues were obtained on day 112(nonirradiated) or day 133(irradiated). Immunohistochemistry was performed to determine tumor cell proliferation(Ki-67) and to assess the expression of infiltration marker(matrix metalloproteinase-2, MMP-2) and cell migration marker(CD44). Tumor neovascularization was assessed by microvessel density using von-Willebrand factor(vWF) staining. Magnetic resonance imaging showed well-developed, infiltrative tumors in 11 weeks postimplantation. The proportion of Ki-67-positive cells in tumors undergoing radiation was(71 ± 15)% compared with(25 ± 12)% in the nonirradiated group(P = 0.02). The number of MMP-2-positive areas and proportion of CD44-positive cells were also high in tumors receiving radiation, indicating great invasion and infiltration. Microvessel density analysis did not show a significant difference between nonirradiated and irradiated tumors. Taken together, we found that subcurative radiation significantly increased proliferation, invasion, and migration of primary GBM. Our study provides insights into possible mechanisms of treatment resistance following radiation therapy for GBM.
文摘A workshop on‘Climate Change and its Impact on Water Resources’was organised by Centre for Earth and Space Science,Uni-versity of Hyderabad,Hyderabad,India during 8th to 10th November 2010.The impact of climate change on freshwater systems and water resources needs to be quantified and modeled for better management.Projected changes in the frequency and severity of extreme climate events have significant consequence on agriculture and food production.A novel idea has been proposed in the model presented in this article,which calls for an integrated approach from various disciplines to create an awareness on climate change effects on agriculture and environment.
文摘鲁尔德巴格勒（Rhourde el Baguel）油田位于古达米斯（Ghadmes）盆地内，是阿尔及利亚最大油田之一，从海平面以下2300—3070m深度寒武系砂岩采油。该构造重新解释为与两条逆断层有关的挤压褶皱，这两条逆断层切割以前的一条正断层并使之变形。构造是在三个主要变形幕期间形成的：①三叠纪至侏罗纪里阿斯期拉张作用，结果形成有大幅度断距的正断层；②中侏罗世里阿斯期盐层流动，结果形成本单元内几个低幅度构造；③早白垩世时期奥地利运动产生挤压作用，结果形成一种基底卷入断层传播褶皱。修改的构造模型阐明了在构造西翼上几口深井中观察的各单元复杂的断层样式和异常厚度变化。此模型已经应用于某些现有深井侧钻进入油田范围内位置，并且优化油田内新钻井位置。
