Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signali...Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.展开更多
Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhes...Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhesion solid bodies. The packed volume and the void ratio of a large number of randomly packed RBCs are clari?ed,and the effects of the RBC shape, the mesh size, the cell number, and the container size are investigated. The results show that the packed human RBCs with normal shape have a void ratio of 28.45%, which is slightly higher than that of the ?at or thick cells used in this study. Such information is bene?cial to the further understanding on the geometric features of human RBCs and the research on RBC simulations.展开更多
The Editor welcomes submissions for possible publication in the Letters to the Editor section. Letters commenting on an article published in the Journal or other interesting pieces will be considered if they are recei...The Editor welcomes submissions for possible publication in the Letters to the Editor section. Letters commenting on an article published in the Journal or other interesting pieces will be considered if they are received within 6 weeks of the time the article was published. Authors of the article being commented on will be given an opportunity to offer a timely response to the letter. Authors of letters will be notified that the letter has been received. Unpublished letters cannot be returned.展开更多
Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by ...Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by Malaria parasite called Plasmodium falciparum, it shows progressive changes in mechanical properties and loses its deformability. The infected red blood cells (IRBCs) develop properties of cytoadherence (stickiness) and rosetting (the binding of non-infected RBCs to parasitized RBCs). In this paper to analyze the mechanical properties and deformability of the IRBC, we applied stress-stretch ratio relation of its biomembrane .To express this constitutive relation, we proposed a mathematical model (Neo-Hookean model) based on membrane theory. On this model, we present continuous stress-stretch ratio curves for the relation derived from the model for different intracellular developmental stages of the parasite, to determine the mechanical properties of IRBC. The analytical results obtained from the mathematical model are more closed with the experimental data [1] which demonstrates the validity of the model. By restricting our attention to spherically symmetric deformation in the final schizont stage of parasite development, the pressure-extension ratio relation curve also adapted from the proposed strain energy function. The change in osmotic pressure versus volumetric ratio has been also considered for IRBC before hemolysis.展开更多
Objective: To probe into the effect of electroacupuncture (EA)on vascular dementia and red cell immune function in the rat. Methods: 30 SD rats were made into renal hypertension rats(RHR) by clamping the kidney arteri...Objective: To probe into the effect of electroacupuncture (EA)on vascular dementia and red cell immune function in the rat. Methods: 30 SD rats were made into renal hypertension rats(RHR) by clamping the kidney arteries with silver clip. 42 days later, their bilateral common carotid arteries were blocked repeatedly to cause cerebral ischemia. The Hypertension vascular dementia model was then set up. Then they were randomly divided into VD model group, EA groupand medication group (Dihydroergotoxine, DHET), with 10 cases in each group. The therapeutic course was 28 days. The ability of learning and memory was using an obs erved by water maze, and the function of red blood cell immune was detected after treatment. Results: the latecy of the EA group and medication group was shorter than that of model group (P<0.05, P<0.005), and that of EA group was shorter than medication group (P<0.05, P<0.005). EA and medication could increase the RBCC 3b receptor flower circle rate and reduce the RBCIC flower circle rate significantly(P<0.05, P< 0.01). Conclusion: The results indicated that EA therapy could raise the ability of learning and memory and improve the function of red cell immune in VD rats, while the therapeutic effect of EAis better than DHET.展开更多
基金supported by the Russian Science Foundation grant(No.22-15-00120)supported by the grant(No.21-2-10-59-1)from the Foundation for the Development of Theoretical Physics and Mathematics BASIS.
文摘Red blood cell(RBC)aggregation as well as their deformation significantly affects blood microrheology.These processes depend on various factors,one of which is concentration of the nitric oxide,one of the main signaling molecule in the bloodstream.The purpose of this study was to investigate the effect of nitric oxide on the microrheological properties of red blood cells(RBCs)in RBC samples of various media after the addition of nitric oxide donor sodium nitroprusside in vitro.Microrheological properties were measured using laser aggregometer and ektacytometer based on diffuse light scattering and diffraction of laser light on a suspension of RBCs,respectively.The study found that heparin-stabilized blood showed increased RBC aggregation and deformation with sodium nitroprusside concentrations of 100,and 200M,while EDTA-stabilized blood showed slightly decreased aggregation and unchanged deformation.With washed RBCs in dextran solution,the addition of sodium nitroprusside(in the concentrations of 100,and 200M)resulted in decreased aggregation and increased deformation.These-ndings aid in our understanding of nitric oxide's effect on RBC microrheological properties.
基金Project supported by the Engineering and Physical Sciences Research Council(EPSRC)Turbulence Consortium Grant(No.EP/G069581/1)the Marie Curie International Incoming Fellowship(No.PIIF-GA-253453)
文摘Numerical simulations are performed to examine the packing behavior of human red blood cells(RBCs). A combined ?nite-discrete element method(FDEM) is utilized, in which the RBCs are modeled as no-friction and no-adhesion solid bodies. The packed volume and the void ratio of a large number of randomly packed RBCs are clari?ed,and the effects of the RBC shape, the mesh size, the cell number, and the container size are investigated. The results show that the packed human RBCs with normal shape have a void ratio of 28.45%, which is slightly higher than that of the ?at or thick cells used in this study. Such information is bene?cial to the further understanding on the geometric features of human RBCs and the research on RBC simulations.
文摘The Editor welcomes submissions for possible publication in the Letters to the Editor section. Letters commenting on an article published in the Journal or other interesting pieces will be considered if they are received within 6 weeks of the time the article was published. Authors of the article being commented on will be given an opportunity to offer a timely response to the letter. Authors of letters will be notified that the letter has been received. Unpublished letters cannot be returned.
文摘Human red blood cells (RBCs) are responsible to transport oxygen and carbon dioxide for human bodies. The physiological functions of RBCs are greatly influenced by their mechanical properties. When RBC is infected by Malaria parasite called Plasmodium falciparum, it shows progressive changes in mechanical properties and loses its deformability. The infected red blood cells (IRBCs) develop properties of cytoadherence (stickiness) and rosetting (the binding of non-infected RBCs to parasitized RBCs). In this paper to analyze the mechanical properties and deformability of the IRBC, we applied stress-stretch ratio relation of its biomembrane .To express this constitutive relation, we proposed a mathematical model (Neo-Hookean model) based on membrane theory. On this model, we present continuous stress-stretch ratio curves for the relation derived from the model for different intracellular developmental stages of the parasite, to determine the mechanical properties of IRBC. The analytical results obtained from the mathematical model are more closed with the experimental data [1] which demonstrates the validity of the model. By restricting our attention to spherically symmetric deformation in the final schizont stage of parasite development, the pressure-extension ratio relation curve also adapted from the proposed strain energy function. The change in osmotic pressure versus volumetric ratio has been also considered for IRBC before hemolysis.
文摘Objective: To probe into the effect of electroacupuncture (EA)on vascular dementia and red cell immune function in the rat. Methods: 30 SD rats were made into renal hypertension rats(RHR) by clamping the kidney arteries with silver clip. 42 days later, their bilateral common carotid arteries were blocked repeatedly to cause cerebral ischemia. The Hypertension vascular dementia model was then set up. Then they were randomly divided into VD model group, EA groupand medication group (Dihydroergotoxine, DHET), with 10 cases in each group. The therapeutic course was 28 days. The ability of learning and memory was using an obs erved by water maze, and the function of red blood cell immune was detected after treatment. Results: the latecy of the EA group and medication group was shorter than that of model group (P<0.05, P<0.005), and that of EA group was shorter than medication group (P<0.05, P<0.005). EA and medication could increase the RBCC 3b receptor flower circle rate and reduce the RBCIC flower circle rate significantly(P<0.05, P< 0.01). Conclusion: The results indicated that EA therapy could raise the ability of learning and memory and improve the function of red cell immune in VD rats, while the therapeutic effect of EAis better than DHET.
文摘目的探讨一氧化氮(NO)对采用percoll密度梯度离心法分离的不同天龄红细胞(RBC)功能状态的影响作用。方法 1)将Percoll细胞分离液配制成5个不连续密度梯度(1.091,1.098 5,1.106,1.113 5,1.121 g/ml),将RBC按平均密度大小分层,依次吸取每层RBC分别做RBC内丙酮酸激酶(PK)含量测定并计算天龄、RBC内ATP含量检测、RBC变形性评价,以及RBC膜蛋白Western Blot。2)从同1份滤白全血中取出2等份,1份为实验组:加适宜浓度的NO溶液,另1份为对照组:加等体积红细胞保存液Ⅲ,分别于保存初期、中期、末期检测2组血液及不同天龄RBC的功能。结果 1)同1份样品经密度梯度离心分离后,RBC随着密度的增大,PK活性逐渐减小(6.192±1.25、5.165±0.84、4.538±0.76,P<0.05)、天龄逐渐增加(10.409、34.957、49.945)、ATP含量逐渐减少(4.755±0.037、3.242±0.445、2.929±0.153,P<0.01)、RBC变形性逐渐降低(200-1切变率下,0.381±0.005、0.340±0.033、0.281±0.028、P<0.05)、RBC膜带3蛋白量减小、聚簇化的带3蛋白量增多、膜上结合的IgG含量增多。2)NO组与对照组相比,全血各指标无明显差异,但NO组保存中、末期老年RBC变形性明显高于对照组(200-1切变率下,中期:0.290±0.021 vs 0.276±0.021、0.229±0.024 vs 0.211±0.027;末期:0.277±0.017 vs0.263±0.019、0.213±0.038 vs 0.193±0.039,P<0.01)。结论 RBC功能随密度的增大逐渐降低;NO可明显改善老年RBC的变形性,但对全血无明显影响。
