Nerve cell metabolism in post brain ischemia depends on increased microcirculation perfusion and transport function of microvascular endothelial cells. In the present study, a rat model of middle cerebral artery occlu...Nerve cell metabolism in post brain ischemia depends on increased microcirculation perfusion and transport function of microvascular endothelial cells. In the present study, a rat model of middle cerebral artery occlusion was established to investigate the influence of electroacupuncture （EA） on hippocampal CA1 cerebral blood flow and glucose transporter 1 （GLUT1） expression in the microvascular endothelial cells. Following EA at Neiguan （PC 6）, the cerebral blood flow in the ischemic hippocampal CA1 region was significantly elevated, the number and microvascular integrated absorbance of the GLUTl-positive cells were significantly increased, nerve cell damage was ameliorated, and GLUT1 protein expression in the ischemic hippocampus was significantly increased. Results demonstrate that EA increased the cerebral blood flow of the hippocampal CA1 region and improved the glucose transport function, thereby attenuating neuronal injuries.展开更多
The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vas...The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vascular-disrupting are used to simulate ＂un-normalized＂ and ＂normalized＂ vasculatures. A new model combining tumor hemodynamics and oxygen transport is developed. In this model, the intravasculartransvascular-interstitial flow with red blood cell（RBC） delivery is tightly coupled, and the oxygen resource is produced by heterogeneous distribution of hematocrit from the flow simulation. The results show that both tumor blood perfusion and hematocrit in the vessels increase, and the hypoxia microenvironment in the tumor center is greatly improved during vascular normalization. The total oxygen content inside the tumor tissue increases by about 67%, 51%, and 95% for the three approaches of vascular normalization,respectively. The elevation of oxygen concentration in tumors can improve its metabolic environment, and consequently reduce malignancy of tumor cells. It can also enhance radiation and chemotherapeutics to tumors.展开更多
A numerical analysis of the steady and pulsatile, macromolecular(such as low density lipopotein (LDL), Albumin) transport in T-bifurcation was proposed. The influence of Reynolds number and mass flow ratio etc. parame...A numerical analysis of the steady and pulsatile, macromolecular(such as low density lipopotein (LDL), Albumin) transport in T-bifurcation was proposed. The influence of Reynolds number and mass flow ratio etc. parameters on the velocity field and mass transport were calculated. The computational results predict that the blood flow factors affect the macromolecular distribution and the transport across the wall, it shows that hemodynamic play an important role in the process of atherosclerosis. The LDL and Albumin concentration on the wall varies most greatly in flow bifurcation area where the wall shear stress varies greatly at the branching vessel and the atherosclerosis often appears there.展开更多
The barriers present in the interfaces between the blood and the central nervous system form a major hurdle for the pharmacological treatment of central nervous system injuries and diseases.The family of ATP-binding c...The barriers present in the interfaces between the blood and the central nervous system form a major hurdle for the pharmacological treatment of central nervous system injuries and diseases.The family of ATP-binding cassette(ABC)transporters has been widely studied regarding efflux of medications at blood-central nervous system barriers.These efflux transporters include P-glycoprotein(abcb1),‘breast cancer resistance protein'(abcg2)and the various‘multidrug resistance-associated proteins'(abccs).Understanding which efflux transporters are present at the blood-spinal cord,blood-cerebrospinal fluid and cerebrospinal fluid-spinal cord barriers is necessary to determine their involvement in limiting drug transfer from blood to the spinal cord tissue.Recent developments in the blood-brain barrier field have shown that barrier systems are dynamic and the profile of barrier defenses can alter due to conditions such as age,disease and environmental challenge.This means that a true understanding of ABC efflux transporter expression and localization should not be one static value but instead a range that represents the complex patient subpopulations that exist.In the present review,the blood-central nervous system barrier literature is discussed with a focus on the impact of ABC efflux transporters on:(i)protecting the spinal cord from adverse effects of systemically directed drugs,and(ii)limiting centrally directed drugs from accessing their active sites within the spinal cord.展开更多
A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary fl...A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow.展开更多
This paper formulates an efficient numerical method for solving the convection diffusion solute transport equations coupled to blood flow equations in vessel networks.The reduced coupled model describes the variations...This paper formulates an efficient numerical method for solving the convection diffusion solute transport equations coupled to blood flow equations in vessel networks.The reduced coupled model describes the variations of vessel cross-sectional area,radially averaged blood momentum and solute concentration in large vessel networks.For the discretization of the reduced transport equation,we combine an interior penalty discontinuous Galerkin method in space with a novel locally implicit time stepping scheme.The stability and the convergence are proved.Numerical results show the impact of the choice for the steady-state axial velocity profile on the numerical solutions in a fifty-five vessel network with physiological boundary data.展开更多
<strong>Objective:</strong> In Japan, red blood cell (RBC) solution is usually transported by car from a medical institution to the patient’s house for home transfusion. However, there are no regulations ...<strong>Objective:</strong> In Japan, red blood cell (RBC) solution is usually transported by car from a medical institution to the patient’s house for home transfusion. However, there are no regulations for transporting blood by car in the medical setting. Therefore, we assessed and compared the methods (containers) used for transporting the RBC solution by car. <strong>Materials and Methods:</strong> Irradiated RBC solution samples (280 mL) supplied by the Japan Red Cross Society were each divided into two bags. The quality of blood transported by car (1 - 2 hours) in an active transport refrigerator (ATR) (control group) was compared with that transported in a cooler, or styrofoam box (study group). We tested the hemolytic effects of transportation by car, storage, and filtration through a transfusion set on the lactate dehydrogenase (LD) levels in the RBC solutions. <strong>Results:</strong> Post-filtered LD levels were significantly higher in the RBC solutions transported in a cooler-box with inadequate temperature control when compared to those transported in an ATR with optimal temperature control. However, under conditions of optimal temperature control, the post-filtered LD levels were comparable in the control and study (both cooler and styrofoam boxes) group RBC solutions. <strong>Conclusion:</strong> Temperature management is critical for the maintenance of the quality of the RBC solution transported by car.展开更多
The dispersion of intravasculary injected nanoparticles can be efficiently described by introducing an effective diffusion coefficient Deff which quantifies the longitudinal mass transport in blood vessels. Here, the ...The dispersion of intravasculary injected nanoparticles can be efficiently described by introducing an effective diffusion coefficient Deff which quantifies the longitudinal mass transport in blood vessels. Here, the original work of Gill and Sankarasubramanian was modified and extended to include 1) the variati- on over time of Deff;2) the permeability of the blood vessels and 3) non-Newtonian rheology of blood. A general solution was provided for Deff depending on space (?), time (?), plug radius (?c) and a subset of permeability parameters. It was shown that increasing the vessel plug radius (thus hematocrit) or permeability leads to a reduction in Deff, limiting the transport of nanoparticles across those vessels. It was also shown that the asymptotic time beyond which the solution attains the steady state behaviour is always independent of the plug radius and wall permeability. The analysis presented can more accurately predict the transport of nanoparticles in blood vessels, compared to previously developed models.展开更多
The purpose of this study was to evaluate the ability of aqueous extract of Aloe barbadensis Miller (Aloe vera) on oxidative damage and Anion Exchanger 1 (AE1, also known as Band 3) expression in human erythrocytes ex...The purpose of this study was to evaluate the ability of aqueous extract of Aloe barbadensis Miller (Aloe vera) on oxidative damage and Anion Exchanger 1 (AE1, also known as Band 3) expression in human erythrocytes exposed to the water soluble free radical initiator 2.2’-azobis-2-amidinopropano dihydrochloride (AAPH). In addition, total phenolic compounds in the extracts were determined as catechin equivalent and the various antioxidant activities were compared to natural and synthetic standard antioxidants such as BHA and ascorbic acid. Since Aloe vera extract did not cause a consumption of the cytosolic antioxidant, glutathione (GSH) when it was direct incubated with GSH in basic aerated aqueous solution, this indicates that Aloe vera extract does not proceed auto oxidation at this experimental condition. Furthermore, Aloe vera extract prevent the consumption of GSH, in radical treated RBCs. It also inhibit consumption of GSH when it was direct incubated with AAPH. Aloe vera gel extract inhibits the generation of diphenyl-2-picrylhy-drazyl (DPPH) and the scavenging activity was increased in a dose dependent manner. Aloe vera extract was shown the similar reducing power than standards BHT and ascorbic acid. Biochemical analysis by SDS-PAGE and western blotting showed that AAPH-induced oxidative stress increased the susceptibility of AE1 to proteolytic degradation. Of note, our data evidenced that Aloe vera treatment was able to partially restore the normal RBC membrane protein profiles in a dose-dependent manner. These results clearly demonstrate the antioxidative activity of Aloe vera gel extract that might be ascribed to a synergistic action of the bioactive compounds contained therein.展开更多
Objective To investigate the potential involvement of DMT1（IRE） protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water,...Objective To investigate the potential involvement of DMT1（IRE） protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the m RNA. Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1（IRE） protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1（IRE） m RNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1（IRE）. Conclusion These results suggest that Pb is transported into the brain through DMT1（IRE）, and the ERK MAPK pathway is involved in DMT1（IRE）-mediated transport regulation in brain vascular system in vivo.展开更多
基金the National Natural Science Foundation of China,No. 30672717
文摘Nerve cell metabolism in post brain ischemia depends on increased microcirculation perfusion and transport function of microvascular endothelial cells. In the present study, a rat model of middle cerebral artery occlusion was established to investigate the influence of electroacupuncture （EA） on hippocampal CA1 cerebral blood flow and glucose transporter 1 （GLUT1） expression in the microvascular endothelial cells. Following EA at Neiguan （PC 6）, the cerebral blood flow in the ischemic hippocampal CA1 region was significantly elevated, the number and microvascular integrated absorbance of the GLUTl-positive cells were significantly increased, nerve cell damage was ameliorated, and GLUT1 protein expression in the ischemic hippocampus was significantly increased. Results demonstrate that EA increased the cerebral blood flow of the hippocampal CA1 region and improved the glucose transport function, thereby attenuating neuronal injuries.
基金Project supported by the National Natural Science Foundation of China(Nos.11102113 and81301816)the New Teachers Start Program of Shanghai Jiao Tong University+1 种基金the Chenxing Young Scholars Program B of Shanghai Jiao Tong University(No.13X100010070)the Natural Science Research Foundation of Shanghai Jiao Tong University School of Medicine(No.13XJ10037)
文摘The changes of blood perfusion and oxygen transport in tumors during tumor vascular normalization are studied with 3-dimensional mathematical modeling and numerical simulation. The models of tumor angiogenesis and vascular-disrupting are used to simulate ＂un-normalized＂ and ＂normalized＂ vasculatures. A new model combining tumor hemodynamics and oxygen transport is developed. In this model, the intravasculartransvascular-interstitial flow with red blood cell（RBC） delivery is tightly coupled, and the oxygen resource is produced by heterogeneous distribution of hematocrit from the flow simulation. The results show that both tumor blood perfusion and hematocrit in the vessels increase, and the hypoxia microenvironment in the tumor center is greatly improved during vascular normalization. The total oxygen content inside the tumor tissue increases by about 67%, 51%, and 95% for the three approaches of vascular normalization,respectively. The elevation of oxygen concentration in tumors can improve its metabolic environment, and consequently reduce malignancy of tumor cells. It can also enhance radiation and chemotherapeutics to tumors.
文摘A numerical analysis of the steady and pulsatile, macromolecular(such as low density lipopotein (LDL), Albumin) transport in T-bifurcation was proposed. The influence of Reynolds number and mass flow ratio etc. parameters on the velocity field and mass transport were calculated. The computational results predict that the blood flow factors affect the macromolecular distribution and the transport across the wall, it shows that hemodynamic play an important role in the process of atherosclerosis. The LDL and Albumin concentration on the wall varies most greatly in flow bifurcation area where the wall shear stress varies greatly at the branching vessel and the atherosclerosis often appears there.
文摘The barriers present in the interfaces between the blood and the central nervous system form a major hurdle for the pharmacological treatment of central nervous system injuries and diseases.The family of ATP-binding cassette(ABC)transporters has been widely studied regarding efflux of medications at blood-central nervous system barriers.These efflux transporters include P-glycoprotein(abcb1),‘breast cancer resistance protein'(abcg2)and the various‘multidrug resistance-associated proteins'(abccs).Understanding which efflux transporters are present at the blood-spinal cord,blood-cerebrospinal fluid and cerebrospinal fluid-spinal cord barriers is necessary to determine their involvement in limiting drug transfer from blood to the spinal cord tissue.Recent developments in the blood-brain barrier field have shown that barrier systems are dynamic and the profile of barrier defenses can alter due to conditions such as age,disease and environmental challenge.This means that a true understanding of ABC efflux transporter expression and localization should not be one static value but instead a range that represents the complex patient subpopulations that exist.In the present review,the blood-central nervous system barrier literature is discussed with a focus on the impact of ABC efflux transporters on:(i)protecting the spinal cord from adverse effects of systemically directed drugs,and(ii)limiting centrally directed drugs from accessing their active sites within the spinal cord.
基金Project supported by the National Natural Science Foundation of China (Nos. 10372007, 30571900 and 10572006)the Natural Science Foundation of Beijing (No.7062015)
文摘A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow.
基金Puelz was supported in part by the Research Training Group in Modeling and Simulation funded by NSF via grant RTG/DMS-1646339Riviere acknowledged the support of NSF via Grant DMS 1913291.
文摘This paper formulates an efficient numerical method for solving the convection diffusion solute transport equations coupled to blood flow equations in vessel networks.The reduced coupled model describes the variations of vessel cross-sectional area,radially averaged blood momentum and solute concentration in large vessel networks.For the discretization of the reduced transport equation,we combine an interior penalty discontinuous Galerkin method in space with a novel locally implicit time stepping scheme.The stability and the convergence are proved.Numerical results show the impact of the choice for the steady-state axial velocity profile on the numerical solutions in a fifty-five vessel network with physiological boundary data.
文摘<strong>Objective:</strong> In Japan, red blood cell (RBC) solution is usually transported by car from a medical institution to the patient’s house for home transfusion. However, there are no regulations for transporting blood by car in the medical setting. Therefore, we assessed and compared the methods (containers) used for transporting the RBC solution by car. <strong>Materials and Methods:</strong> Irradiated RBC solution samples (280 mL) supplied by the Japan Red Cross Society were each divided into two bags. The quality of blood transported by car (1 - 2 hours) in an active transport refrigerator (ATR) (control group) was compared with that transported in a cooler, or styrofoam box (study group). We tested the hemolytic effects of transportation by car, storage, and filtration through a transfusion set on the lactate dehydrogenase (LD) levels in the RBC solutions. <strong>Results:</strong> Post-filtered LD levels were significantly higher in the RBC solutions transported in a cooler-box with inadequate temperature control when compared to those transported in an ATR with optimal temperature control. However, under conditions of optimal temperature control, the post-filtered LD levels were comparable in the control and study (both cooler and styrofoam boxes) group RBC solutions. <strong>Conclusion:</strong> Temperature management is critical for the maintenance of the quality of the RBC solution transported by car.
文摘The dispersion of intravasculary injected nanoparticles can be efficiently described by introducing an effective diffusion coefficient Deff which quantifies the longitudinal mass transport in blood vessels. Here, the original work of Gill and Sankarasubramanian was modified and extended to include 1) the variati- on over time of Deff;2) the permeability of the blood vessels and 3) non-Newtonian rheology of blood. A general solution was provided for Deff depending on space (?), time (?), plug radius (?c) and a subset of permeability parameters. It was shown that increasing the vessel plug radius (thus hematocrit) or permeability leads to a reduction in Deff, limiting the transport of nanoparticles across those vessels. It was also shown that the asymptotic time beyond which the solution attains the steady state behaviour is always independent of the plug radius and wall permeability. The analysis presented can more accurately predict the transport of nanoparticles in blood vessels, compared to previously developed models.
文摘The purpose of this study was to evaluate the ability of aqueous extract of Aloe barbadensis Miller (Aloe vera) on oxidative damage and Anion Exchanger 1 (AE1, also known as Band 3) expression in human erythrocytes exposed to the water soluble free radical initiator 2.2’-azobis-2-amidinopropano dihydrochloride (AAPH). In addition, total phenolic compounds in the extracts were determined as catechin equivalent and the various antioxidant activities were compared to natural and synthetic standard antioxidants such as BHA and ascorbic acid. Since Aloe vera extract did not cause a consumption of the cytosolic antioxidant, glutathione (GSH) when it was direct incubated with GSH in basic aerated aqueous solution, this indicates that Aloe vera extract does not proceed auto oxidation at this experimental condition. Furthermore, Aloe vera extract prevent the consumption of GSH, in radical treated RBCs. It also inhibit consumption of GSH when it was direct incubated with AAPH. Aloe vera gel extract inhibits the generation of diphenyl-2-picrylhy-drazyl (DPPH) and the scavenging activity was increased in a dose dependent manner. Aloe vera extract was shown the similar reducing power than standards BHT and ascorbic acid. Biochemical analysis by SDS-PAGE and western blotting showed that AAPH-induced oxidative stress increased the susceptibility of AE1 to proteolytic degradation. Of note, our data evidenced that Aloe vera treatment was able to partially restore the normal RBC membrane protein profiles in a dose-dependent manner. These results clearly demonstrate the antioxidative activity of Aloe vera gel extract that might be ascribed to a synergistic action of the bioactive compounds contained therein.
基金supported by National Natural Science Foundation of China(No.81472478)Medical Science Youth Breeding Project of PLA(13QNP161)
文摘Objective To investigate the potential involvement of DMT1（IRE） protein in the brain vascular system in vivo during Pb exposure. Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the m RNA. Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1（IRE） protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1（IRE） m RNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1（IRE）. Conclusion These results suggest that Pb is transported into the brain through DMT1（IRE）, and the ERK MAPK pathway is involved in DMT1（IRE）-mediated transport regulation in brain vascular system in vivo.
