The influence of fibrinogen concentration on blood dielectric properties has been analyzed by GHz electrical impedance spectroscopy (EIS). The complex impedances of native blood and blood with various fibrinogen concentrations Z*blood,exp were measured by a coaxial sensor in the frequency range from 1 MHz to 3 GHz. The complex permittivity of native blood and blood with various fibrinogen concentrations ε*blood were extracted from the Z*blood,exp by equivalent circuit model based on the transmission line theory. The reactance Xblood,native and resistance Rsblood,native of native blood have a peak called characteristic frequency fc at around 300 MHz. At the time t = 0 min just after fibrinogen addition, the relative blood permittivity εblood decreases, conductivities σblood increases and fc shifts to higher frequency with increase of fibrinogen concentrations cfib in plasma. With increment of time, from t = 0 min to t = 12 min, εblood decreases while σblood slightly decreases to time because red blood cell (RBC) aggregation reaction. By comparing the εblood,native of native blood and blood with various cfib, the fibrinogen dissolved in plasma rises the blood permittivity. However, fibrinogen is unable to rise the blood permittivity unlimitedly because of RBC aggregation reaction.
{"title":"Analysis of influence of fibrinogen concentration on blood dielectric properties by GHz electrical impedance spectroscopy","authors":"An Zhang, D. Kawashima, H. Obara, M. Takei","doi":"10.17106/jbr.34.38","DOIUrl":"https://doi.org/10.17106/jbr.34.38","url":null,"abstract":"The influence of fibrinogen concentration on blood dielectric properties has been analyzed by GHz electrical impedance spectroscopy (EIS). The complex impedances of native blood and blood with various fibrinogen concentrations Z*blood,exp were measured by a coaxial sensor in the frequency range from 1 MHz to 3 GHz. The complex permittivity of native blood and blood with various fibrinogen concentrations ε*blood were extracted from the Z*blood,exp by equivalent circuit model based on the transmission line theory. The reactance Xblood,native and resistance Rsblood,native of native blood have a peak called characteristic frequency fc at around 300 MHz. At the time t = 0 min just after fibrinogen addition, the relative blood permittivity εblood decreases, conductivities σblood increases and fc shifts to higher frequency with increase of fibrinogen concentrations cfib in plasma. With increment of time, from t = 0 min to t = 12 min, εblood decreases while σblood slightly decreases to time because red blood cell (RBC) aggregation reaction. By comparing the εblood,native of native blood and blood with various cfib, the fibrinogen dissolved in plasma rises the blood permittivity. However, fibrinogen is unable to rise the blood permittivity unlimitedly because of RBC aggregation reaction.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/jbr.34.38","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Ando, N. Shimada, Kenichiro Asano, T. Kikutsuji, S. Mochizuki
To develop a novel index of body water distribution status in hemodialysis (HD) patients, we derived equations that estimate the excess fluid volume (ExFv) in HD patients, and evaluated their applicability. The ExFv estimation equations were derived based on the correlations between extracellular water (ECW) and total body water (TBW) volumes of healthy adults, which were measured using multifrequency bioelectrical impedance analysis. Here, the effect of increasing ECW/TBW with age was corrected. The estimated ExFv and the circulatory and body fluid status of HD patients were compared between two groups of 20 patients with dry weight (DW) and 16 patients with overhydration (OH), both of which were clinically classified. The indices of circulatory and body fluid status were significantly higher in the OH group than in the DW group. The ExFv values of the DW and OH groups were 0.06 ± 0.19 L and 0.78 ± 0.32 L in males and 0.06 ± 0.16 L and 0.51 ± 0.18 L in females, respectively, indicating significantly higher values in the OH group. The derived ExFv estimation equations allow us a simple and quantitative assessment of the body water distribution status in HD patients.
{"title":"Simple estimation of excess fluid volume in hemodialysis patients based on multifrequency bioelectrical impedance analysis data","authors":"M. Ando, N. Shimada, Kenichiro Asano, T. Kikutsuji, S. Mochizuki","doi":"10.17106/jbr.34.55","DOIUrl":"https://doi.org/10.17106/jbr.34.55","url":null,"abstract":"To develop a novel index of body water distribution status in hemodialysis (HD) patients, we derived equations that estimate the excess fluid volume (ExFv) in HD patients, and evaluated their applicability. The ExFv estimation equations were derived based on the correlations between extracellular water (ECW) and total body water (TBW) volumes of healthy adults, which were measured using multifrequency bioelectrical impedance analysis. Here, the effect of increasing ECW/TBW with age was corrected. The estimated ExFv and the circulatory and body fluid status of HD patients were compared between two groups of 20 patients with dry weight (DW) and 16 patients with overhydration (OH), both of which were clinically classified. The indices of circulatory and body fluid status were significantly higher in the OH group than in the DW group. The ExFv values of the DW and OH groups were 0.06 ± 0.19 L and 0.78 ± 0.32 L in males and 0.06 ± 0.16 L and 0.51 ± 0.18 L in females, respectively, indicating significantly higher values in the OH group. The derived ExFv estimation equations allow us a simple and quantitative assessment of the body water distribution status in HD patients.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Objective: Single-nephron glomerular filtration rate (SNGFR) is an important and valuable parameter for evaluating renal function. Previously, SNGFR measure-ments required radioactive labelling of isolated animal nephrons, which was a time-consuming and inefficient process. Owing to the development of laser confocal microscopy, in vivo renal visualisation became much simpler, facilitated by the use of fluorescent markers. In this study, the effects of C-peptide on hyperfiltration reversal were evaluated during the early stages of diabetes mellitus (DM). Methods: Wistar rats (n = 17) were divided into control and streptozotocin-induced DM groups. Analyses were performed at 2 and 6 weeks following induction. Lucifer Yellow was administered by bolus injection to visualise tubular urinary flow using a laser confocal microscope. Results: SNGFR increased in diabetic rats ( p < 0.05) and decreased by approximately 40% following C-peptide administration ( p < 0.05). Moreover, tubular luminal flow increased ( p < 0.05), as previously reported, but decreased by 3–11% after C-peptide administration in 6-week diabetic rats without significance. Conclusion: Confocal microscopy demonstrated that C-peptide administration decreases SNGFR and tubular luminal flow in diabetic rats.
{"title":"Effects of C-peptide on the single-nephron glomerular filtration rate in early diabetic rats","authors":"H. Nakamoto","doi":"10.17106/jbr.34.2","DOIUrl":"https://doi.org/10.17106/jbr.34.2","url":null,"abstract":"Objective: Single-nephron glomerular filtration rate (SNGFR) is an important and valuable parameter for evaluating renal function. Previously, SNGFR measure-ments required radioactive labelling of isolated animal nephrons, which was a time-consuming and inefficient process. Owing to the development of laser confocal microscopy, in vivo renal visualisation became much simpler, facilitated by the use of fluorescent markers. In this study, the effects of C-peptide on hyperfiltration reversal were evaluated during the early stages of diabetes mellitus (DM). Methods: Wistar rats (n = 17) were divided into control and streptozotocin-induced DM groups. Analyses were performed at 2 and 6 weeks following induction. Lucifer Yellow was administered by bolus injection to visualise tubular urinary flow using a laser confocal microscope. Results: SNGFR increased in diabetic rats ( p < 0.05) and decreased by approximately 40% following C-peptide administration ( p < 0.05). Moreover, tubular luminal flow increased ( p < 0.05), as previously reported, but decreased by 3–11% after C-peptide administration in 6-week diabetic rats without significance. Conclusion: Confocal microscopy demonstrated that C-peptide administration decreases SNGFR and tubular luminal flow in diabetic rats.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low-porosity stents such as flow diverters and the flow isolator, which we developed in a previous study, are expected to provide an effective and minimally invasive treatment for intracranial aneurysms (IAs). After inserting a stent, thrombus formation is promoted by the stagnation of IA blood flow. Consequently, IA embolization can occur. Therefore, IA flow intensity significantly affects IA emboli zation treatment. IA morphology such as aneurysm size, aspect ratio, and bottleneck factor are important parameters as general indices of IA rupture. Meanwhile, existing litera-ture suggests that IA morphology is considerably affected by IA flow and IA embolization. Hence, this work investi gates the relationship between IA flow intensity and IA morphology by using particle imaging velocimetry (PIV) and in vitro flow simulation with IA and parent vessel models. The PIV results showed that the area mean shear rate (AMSR), a hemodynamical index of thrombus formation, was higher in IA models with higher neck widths, lower aneurysm heights, and smaller dome sizes. This implies that thrombus formation is inhibited in a wide-neck and small aneurysm. Moreover, stents with effective flow-reduction properties are required for a reliable IA embolization treat -ment. The AMSR was well expressed by a power function using the Reynolds number and IA morphology as parameters.
{"title":"In vitro hydrodynamical study on aneurysmal morphology for treating intracranial aneurysms using particle imaging velocimetry","authors":"T. Moriwaki, T. Tajikawa, Y. Nakayama","doi":"10.17106/jbr.34.47","DOIUrl":"https://doi.org/10.17106/jbr.34.47","url":null,"abstract":"Low-porosity stents such as flow diverters and the flow isolator, which we developed in a previous study, are expected to provide an effective and minimally invasive treatment for intracranial aneurysms (IAs). After inserting a stent, thrombus formation is promoted by the stagnation of IA blood flow. Consequently, IA embolization can occur. Therefore, IA flow intensity significantly affects IA emboli zation treatment. IA morphology such as aneurysm size, aspect ratio, and bottleneck factor are important parameters as general indices of IA rupture. Meanwhile, existing litera-ture suggests that IA morphology is considerably affected by IA flow and IA embolization. Hence, this work investi gates the relationship between IA flow intensity and IA morphology by using particle imaging velocimetry (PIV) and in vitro flow simulation with IA and parent vessel models. The PIV results showed that the area mean shear rate (AMSR), a hemodynamical index of thrombus formation, was higher in IA models with higher neck widths, lower aneurysm heights, and smaller dome sizes. This implies that thrombus formation is inhibited in a wide-neck and small aneurysm. Moreover, stents with effective flow-reduction properties are required for a reliable IA embolization treat -ment. The AMSR was well expressed by a power function using the Reynolds number and IA morphology as parameters.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erythrocytes are the most abundant cells and acting as carrier, deliverer and sensor of oxygen. Therefore, human erythrocyte behavior is a fundamental health indicator. Lifespan of circulating erythrocytes is about 120 days, and hence erythrocyte population shows distribution of aging. The physicochemical property of hemoglobin (Hb) influences the density and the deformability of erythrocytes. Senescent erythrocytes are dense, shrunk, less deformable and finally removed from circulation by several mechanisms such as phagocytosis and eryptosis. Earlier removal leads to the short lifespan of less deformable erythrocytes. Herein, anemic and cardiometabolic diseases are presented in order to consider the relationship between the agedependent erythrocyte density and deformability. The main cause of impaired deformability in sickle cell disease is the presence of dense cells characterized by cellular dehydration and polymerization of sickle Hb, that in hereditary hemolytic diseases is cellular geometry, and that in iron deficiency anemia is an increased susceptibility of lighter erythrocytes to the oxidative stress. Diabetic erythrocytes show seemingly normal density and reduced deformability under the enhanced oxidative stress. This article addresses that distribution profiles of both erythrocyte density and deformability are important for better understanding of the encapsulated Hb interacting membrane of erythrocytes showing individual aging.
{"title":"Physiological and pathophysiological significance of erythrocyte senescence, density and deformability: Important but unnoticed trinity","authors":"T. Maruyama, Mitsuhiro Fukata, T. Fujino","doi":"10.17106/jbr.34.61","DOIUrl":"https://doi.org/10.17106/jbr.34.61","url":null,"abstract":"Erythrocytes are the most abundant cells and acting as carrier, deliverer and sensor of oxygen. Therefore, human erythrocyte behavior is a fundamental health indicator. Lifespan of circulating erythrocytes is about 120 days, and hence erythrocyte population shows distribution of aging. The physicochemical property of hemoglobin (Hb) influences the density and the deformability of erythrocytes. Senescent erythrocytes are dense, shrunk, less deformable and finally removed from circulation by several mechanisms such as phagocytosis and eryptosis. Earlier removal leads to the short lifespan of less deformable erythrocytes. Herein, anemic and cardiometabolic diseases are presented in order to consider the relationship between the agedependent erythrocyte density and deformability. The main cause of impaired deformability in sickle cell disease is the presence of dense cells characterized by cellular dehydration and polymerization of sickle Hb, that in hereditary hemolytic diseases is cellular geometry, and that in iron deficiency anemia is an increased susceptibility of lighter erythrocytes to the oxidative stress. Diabetic erythrocytes show seemingly normal density and reduced deformability under the enhanced oxidative stress. This article addresses that distribution profiles of both erythrocyte density and deformability are important for better understanding of the encapsulated Hb interacting membrane of erythrocytes showing individual aging.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68198004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Intra- and inter-cellular Ca 2+ waves play key roles in cellular functions. Focal stimulation triggers Ca 2+ wave propagation from the stimulation point to neighboring cells through the cytoplasm, which involves localized metabolism reactions and specific diffusion processes. Briefly, inositol 1,4,5-trisphosphate (IP 3 ) is produced at membranes and diffuses into the cytoplasm, resulting in Ca 2+ release from the endoplasmic reticulum (ER). Particu-larly, Ca 2+ released from the ER is mediated by two princi-ples, the IP 3 -induced Ca 2+ and Ca 2+ -induced Ca 2+ releases. Ca 2+ is diffused through the cytoplasm and, furthermore, transported into neighboring cells through gap junctions. These intra- and inter-cellular Ca 2+ waves have been widely investigated using theoretical and experimental methods in various cell types. In this review we summarize the mathematical models used for the numerical simulation of intra-and inter-cellular Ca 2+ wave propagations.
{"title":"Mathematical models for intra- and inter-cellular Ca2+ wave propagations","authors":"T. Sera, S. Kudo","doi":"10.17106/jbr.34.9","DOIUrl":"https://doi.org/10.17106/jbr.34.9","url":null,"abstract":"Intra- and inter-cellular Ca 2+ waves play key roles in cellular functions. Focal stimulation triggers Ca 2+ wave propagation from the stimulation point to neighboring cells through the cytoplasm, which involves localized metabolism reactions and specific diffusion processes. Briefly, inositol 1,4,5-trisphosphate (IP 3 ) is produced at membranes and diffuses into the cytoplasm, resulting in Ca 2+ release from the endoplasmic reticulum (ER). Particu-larly, Ca 2+ released from the ER is mediated by two princi-ples, the IP 3 -induced Ca 2+ and Ca 2+ -induced Ca 2+ releases. Ca 2+ is diffused through the cytoplasm and, furthermore, transported into neighboring cells through gap junctions. These intra- and inter-cellular Ca 2+ waves have been widely investigated using theoretical and experimental methods in various cell types. In this review we summarize the mathematical models used for the numerical simulation of intra-and inter-cellular Ca 2+ wave propagations.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68198213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Infection control and protection from the emerging diseases should be rationally formulated and operated based on epidemiologically determined infection characteristics. In order to respond to this requirement, this study proposes a mathematical model of the progression of the spread of viral infection in the society. In addition, the model was applied to cases of transmission of the new coronavirus COVID-19. From the results, the following is clarified: the progress of the viral infection can be simply modeled by the daily-rate basic reproduction number r and the infection detection rate k; r is determined by the epidemiologically determined values of basic reproduction number Ro and the infection lifetime T of virus; the dailyrate effective reproduction number reff can be defined by reff = r(1 – k), and reff < 1 indicates that the infection is suppressed; the infection suppression can be realized to make k greater than the critical value kcr corresponding to the epidemiological parameters; this model fits well with the practical infection behavior of COVID-19 and enables the quantitative evaluation of infection suppress measures; In the case of China, thorough detecting and isolation would have improved the infection condition to the suppression phase after only 10 days.
{"title":"Modeling of viral infection behavior to evaluate countermeasures against infection causing social disaster","authors":"Haruhisa Sakamoto, H. Ujiié","doi":"10.17106/jbr.34.79","DOIUrl":"https://doi.org/10.17106/jbr.34.79","url":null,"abstract":"Infection control and protection from the emerging diseases should be rationally formulated and operated based on epidemiologically determined infection characteristics. In order to respond to this requirement, this study proposes a mathematical model of the progression of the spread of viral infection in the society. In addition, the model was applied to cases of transmission of the new coronavirus COVID-19. From the results, the following is clarified: the progress of the viral infection can be simply modeled by the daily-rate basic reproduction number r and the infection detection rate k; r is determined by the epidemiologically determined values of basic reproduction number Ro and the infection lifetime T of virus; the dailyrate effective reproduction number reff can be defined by reff = r(1 – k), and reff < 1 indicates that the infection is suppressed; the infection suppression can be realized to make k greater than the critical value kcr corresponding to the epidemiological parameters; this model fits well with the practical infection behavior of COVID-19 and enables the quantitative evaluation of infection suppress measures; In the case of China, thorough detecting and isolation would have improved the infection condition to the suppression phase after only 10 days.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68198097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we investigated the spatial and temporal reorganization of actin filaments in living endothelial cells in response to shear stress by transfecting a fluorescent protein, Dronpa-Green-labeled actin, which was photoactivated microscopically by UV irradiation, and evaluating the time constants of fluorescence decay after photoactivation. The time constant in the upstream region decreased gradually after 30 min of shear stress and then increased. Particularly, the time constant in the downstream region tended to be higher than in the upstream region, suggesting that actin polymerization was more activated in the downstream region. Our results demonstrated the spatial and temporal heterogeneity of actin reorganization due to shear stress.
{"title":"Heterogeneous reorganization of actin filaments in living endothelial cells in response to shear stress","authors":"T. Sera, Marie Terada, S. Kudo","doi":"10.17106/jbr.34.18","DOIUrl":"https://doi.org/10.17106/jbr.34.18","url":null,"abstract":"In this study, we investigated the spatial and temporal reorganization of actin filaments in living endothelial cells in response to shear stress by transfecting a fluorescent protein, Dronpa-Green-labeled actin, which was photoactivated microscopically by UV irradiation, and evaluating the time constants of fluorescence decay after photoactivation. The time constant in the upstream region decreased gradually after 30 min of shear stress and then increased. Particularly, the time constant in the downstream region tended to be higher than in the upstream region, suggesting that actin polymerization was more activated in the downstream region. Our results demonstrated the spatial and temporal heterogeneity of actin reorganization due to shear stress.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we try to extract the dynamics of the dislocations by measuring the time auto-correlation function of the scattered light intensity in the dilute lamellar phase. Our finding is that the lyotropic lamellar phase shows a bimodal decay of the correlation function. Fitting with the dispersion relation for the undulation fluctuation indicates that the fast mode is attributed to the undulation fluctuation of bilayer membranes. On the other hand, the slow relaxation mode is not explained by the undulation fluctuation. We interpret that the slow mode would be originated from a climb motion of the dislocation. Bimodal relaxation process would be attributed to a heterogeneous distribution of the dislocations in the lamellar structure.
{"title":"Notes on the slow dynamics in dilute lyotropic lamellar phase","authors":"S. Fujii, Y. Sasaki, H. Orihara","doi":"10.17106/JBR.33.8","DOIUrl":"https://doi.org/10.17106/JBR.33.8","url":null,"abstract":"In this study, we try to extract the dynamics of the dislocations by measuring the time auto-correlation function of the scattered light intensity in the dilute lamellar phase. Our finding is that the lyotropic lamellar phase shows a bimodal decay of the correlation function. Fitting with the dispersion relation for the undulation fluctuation indicates that the fast mode is attributed to the undulation fluctuation of bilayer membranes. On the other hand, the slow relaxation mode is not explained by the undulation fluctuation. We interpret that the slow mode would be originated from a climb motion of the dislocation. Bimodal relaxation process would be attributed to a heterogeneous distribution of the dislocations in the lamellar structure.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Junfeng Wang, Shukei Sugita, T. Michiue, T. Tsuboi, T. Kitaguchi, Takeo Matsumoto
Actin stress fibers (SFs) generate tension and play crucial roles in multiple cellular functions. However, it remains unclear how the tension changes in a single SF during cell movement on a substrate. In this study, we developed a new method to analyze the change in tension in a single SF in a cell with a Förster resonance energy transfer (FRET)-based tension sensor. With this new method, we have evaluated the relationship between the movement of SFs in the bottom of an MC3T3-E1 cell and their FRET ratio change, i.e., the tension change, for the first time to our knowledge. We found that the tension in SFs decreases when they rotate. The tension had no significant correlation with their translation nor with their length change.
{"title":"A novel FRET analysis method for tension dynamics in a single actin stress fiber: Application to MC3T3-E1 cells during movement on a substrate","authors":"Junfeng Wang, Shukei Sugita, T. Michiue, T. Tsuboi, T. Kitaguchi, Takeo Matsumoto","doi":"10.17106/JBR.33.21","DOIUrl":"https://doi.org/10.17106/JBR.33.21","url":null,"abstract":"Actin stress fibers (SFs) generate tension and play crucial roles in multiple cellular functions. However, it remains unclear how the tension changes in a single SF during cell movement on a substrate. In this study, we developed a new method to analyze the change in tension in a single SF in a cell with a Förster resonance energy transfer (FRET)-based tension sensor. With this new method, we have evaluated the relationship between the movement of SFs in the bottom of an MC3T3-E1 cell and their FRET ratio change, i.e., the tension change, for the first time to our knowledge. We found that the tension in SFs decreases when they rotate. The tension had no significant correlation with their translation nor with their length change.","PeriodicalId":39272,"journal":{"name":"Journal of Biorheology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.17106/JBR.33.21","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68197724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：