Blood cells are mainly(~99%)comprised of red blood cells.The most remarkable properties of are their high deformability,which allow they flow through microcapillaries of diameter even smaller than their size.The RBC’...Blood cells are mainly(~99%)comprised of red blood cells.The most remarkable properties of are their high deformability,which allow they flow through microcapillaries of diameter even smaller than their size.The RBC’s remarkable mechanical properties originate from the unique architecture of its membrane.To study the mechanism of RBC’s deformability,a commonly adopted approach is to localize the cytoskeleton protein by immunofluorescence,followed by exploring the changes of cytoskeleton protein during cell deformation.During this process,the fixed treatment of RBC using GA and PFA is of great importance.However,RBC’s deformability is reduced by the fixation process and skeletal protein of membrane is changed accordingly.The flow behavior of red RBCs through the microchannel also changed.Given the difficulty of observing RBC flow in vivo,in vitro simulation by virtue of microfluidic devices provides a feasible alternative.An important physiological phenomenon of the blood flow is the formation of cell free layer(CFL),with RBCs show a tendency to concentrate towards the central axis of the pipeline and move faster than the plasma layer.However,this phenomena is weaken if the stiffness of the membrane increase,which occurs in some disease,such as hereditary spherocytosis and hereditary elliptocytosis.To study the effects of GA and PFA fix treatment on RBC deformability,a microfluidic platform is employed to measuring the CFL and flow velocity of blood flow in this work.The PDMS micro flow channel used is 100 micrometers in width and 50 micrometers in deep.The RBC suspension is fed into the flow channel by the injection pump(NE-1000.USA),and the experiments are observed and recorded by the inverted microscope(IX70,Olympus,Japan)and high-speed camera(Memrecam GX-1,NAC,Japan)system.Three GA concentrations,i.e.,0.000 5,0.000 75,and 0.001 wt.%were used.Meanwhile,the effect of PFA at a concentration of 2wt.%work with GA was also investigated.Images of the flowing RBCs are processed mainly based on Memrecam GXLink.The results show that,the diameter of the RBC be treated is bigger and the shape of the RBC is became more flat after treated.Some of RBCs lost their biconcave structure.When the RBC suspension with 5%Hct flow in the microchannel,the CFL thickness decrease after being treated.And with concentrations of GA increase,the CFL thickness become thinner.The CFL thickness decrease significantly when GA and 2 wt.%PFA work combined.The velocity of RBCs decreases after treated with the GA or/and 2wt.%PFA.GA is known to relieve the dissolution of red blood cells during fluorescence labeling.On the other hand,the crosslinking of the aldehyde group(-cho)of GA with the amino group(-nh2)of RBC membrane protein will change the conformation of the membrane protein and its visco-elastic properties in turn.Then,the transparent fluidity orrheology characteristics of RBC is altered.Since GA and PFA are commonly used to immobilize red blood cells and keep the fluorescence constant,and PFA works similarly as GA,as a result,the variation of membrane protein conformation is intensified,and the membrane becomes stiffer.展开更多
目的探讨外周血红细胞分布宽度(red blood cell distribution width,RDW)、系统免疫炎症指数(systemic immune-inflammation index,SⅡ)与重性抑郁障碍(major depressive disorder,MDD)的相关性。方法回顾性分析2020-2022年于我院临床...目的探讨外周血红细胞分布宽度(red blood cell distribution width,RDW)、系统免疫炎症指数(systemic immune-inflammation index,SⅡ)与重性抑郁障碍(major depressive disorder,MDD)的相关性。方法回顾性分析2020-2022年于我院临床心理科住院的176例MDD患者和常规体检的209例非MDD对照者的临床资料。从血液分析结果中,得到RDW、SⅡ、红细胞分布宽度与血小板计数比值(RDW to platelet ratio,RPR)。绘制受试者操作特征(receiver operator characteristic,ROC)曲线以确定RDW区分患者与对照的最佳临界值及曲线下面积(area under the curve,AUC)。结果MDD组患者的RDW[中位数及四分位数:13.20(12.70,13.98)vs.12.80(12.40,13.35)]、SⅡ水平[中位数及四分位数:510.87(350.95,878.12)vs.405.33(313.74,539.92)]高于非MDD组对照者,差异有统计学意义(P<0.05),两组间RPR差异无统计学意义(P>0.05)。多因素logistic回归分析结果显示,调整混杂因素后,RDW与MDD呈正关联(OR=3.086,95%CI:1.926~4.944)。ROC曲线结果显示,RDW区分MDD与非MDD的最佳临界值为12.85,AUC为0.647(95%CI:0.592~0.702;P<0.001)。结论高RDW可能是MDD发生的危险因素,是对MDD诊断有价值的重要参数。展开更多
文摘Blood cells are mainly(~99%)comprised of red blood cells.The most remarkable properties of are their high deformability,which allow they flow through microcapillaries of diameter even smaller than their size.The RBC’s remarkable mechanical properties originate from the unique architecture of its membrane.To study the mechanism of RBC’s deformability,a commonly adopted approach is to localize the cytoskeleton protein by immunofluorescence,followed by exploring the changes of cytoskeleton protein during cell deformation.During this process,the fixed treatment of RBC using GA and PFA is of great importance.However,RBC’s deformability is reduced by the fixation process and skeletal protein of membrane is changed accordingly.The flow behavior of red RBCs through the microchannel also changed.Given the difficulty of observing RBC flow in vivo,in vitro simulation by virtue of microfluidic devices provides a feasible alternative.An important physiological phenomenon of the blood flow is the formation of cell free layer(CFL),with RBCs show a tendency to concentrate towards the central axis of the pipeline and move faster than the plasma layer.However,this phenomena is weaken if the stiffness of the membrane increase,which occurs in some disease,such as hereditary spherocytosis and hereditary elliptocytosis.To study the effects of GA and PFA fix treatment on RBC deformability,a microfluidic platform is employed to measuring the CFL and flow velocity of blood flow in this work.The PDMS micro flow channel used is 100 micrometers in width and 50 micrometers in deep.The RBC suspension is fed into the flow channel by the injection pump(NE-1000.USA),and the experiments are observed and recorded by the inverted microscope(IX70,Olympus,Japan)and high-speed camera(Memrecam GX-1,NAC,Japan)system.Three GA concentrations,i.e.,0.000 5,0.000 75,and 0.001 wt.%were used.Meanwhile,the effect of PFA at a concentration of 2wt.%work with GA was also investigated.Images of the flowing RBCs are processed mainly based on Memrecam GXLink.The results show that,the diameter of the RBC be treated is bigger and the shape of the RBC is became more flat after treated.Some of RBCs lost their biconcave structure.When the RBC suspension with 5%Hct flow in the microchannel,the CFL thickness decrease after being treated.And with concentrations of GA increase,the CFL thickness become thinner.The CFL thickness decrease significantly when GA and 2 wt.%PFA work combined.The velocity of RBCs decreases after treated with the GA or/and 2wt.%PFA.GA is known to relieve the dissolution of red blood cells during fluorescence labeling.On the other hand,the crosslinking of the aldehyde group(-cho)of GA with the amino group(-nh2)of RBC membrane protein will change the conformation of the membrane protein and its visco-elastic properties in turn.Then,the transparent fluidity orrheology characteristics of RBC is altered.Since GA and PFA are commonly used to immobilize red blood cells and keep the fluorescence constant,and PFA works similarly as GA,as a result,the variation of membrane protein conformation is intensified,and the membrane becomes stiffer.
文摘目的探讨外周血红细胞分布宽度(red blood cell distribution width,RDW)、系统免疫炎症指数(systemic immune-inflammation index,SⅡ)与重性抑郁障碍(major depressive disorder,MDD)的相关性。方法回顾性分析2020-2022年于我院临床心理科住院的176例MDD患者和常规体检的209例非MDD对照者的临床资料。从血液分析结果中,得到RDW、SⅡ、红细胞分布宽度与血小板计数比值(RDW to platelet ratio,RPR)。绘制受试者操作特征(receiver operator characteristic,ROC)曲线以确定RDW区分患者与对照的最佳临界值及曲线下面积(area under the curve,AUC)。结果MDD组患者的RDW[中位数及四分位数:13.20(12.70,13.98)vs.12.80(12.40,13.35)]、SⅡ水平[中位数及四分位数:510.87(350.95,878.12)vs.405.33(313.74,539.92)]高于非MDD组对照者,差异有统计学意义(P<0.05),两组间RPR差异无统计学意义(P>0.05)。多因素logistic回归分析结果显示,调整混杂因素后,RDW与MDD呈正关联(OR=3.086,95%CI:1.926~4.944)。ROC曲线结果显示,RDW区分MDD与非MDD的最佳临界值为12.85,AUC为0.647(95%CI:0.592~0.702;P<0.001)。结论高RDW可能是MDD发生的危险因素,是对MDD诊断有价值的重要参数。
