Abstract:
:The rate of onset of erythrocyte flow orientation at normal concentration has not previously been established. Reflectivity of blood and resuspended non-aggregated red cells at normal (41%) and elevated (60%) hematocrit has been used to examine this process. Video recordings were made before, during, and after shearing by bob motion in a cylinder-in-cylinder viscometer at shear rates ranging from 4 to 100 inverse seconds. Unaggregated erythrocytes in PBS, already more reflective than blood before shearing, became even more reflective during shearing even at the lowest shear rate studied. The time required for the increased reflectivity to stabilize was observed to be inversely proportional to shear rate for both blood and resuspended red cells. Reflection became constant after a total shear strain (bob shear rate x time) from 4 to 10 at all shear rates studied. Onset of increased reflection expressed in total shear strain units (an index of overall bob movement) was independent of shear rate in the absence of aggregation. When red cells were studied in native plasma, reflectivity increased as much as 30% during shearing, but always remained below unaggregated red cell reflectivity for the same hematocrit and shear rate. Greater reflectivity of unaggregated red cells persisted after cessation of shearing, while blood's reflectivity dropped progressively over several seconds to its pre-shearing value. The geometry chosen for study and insensitivity to light source composition indicate that specular reflection by red cells near the cup's inner surface is responsible for the increased light return during flow. Maximal rate of rise in reflectivity at all shear rates studied was observed to coincide with blood's previously reported transient shear stress overshoot and to correspond with an overall bob motion that would rotate suspended particles approximately 45 degrees. The close relation of both reflectivity increase and shear stress overshoot to such modest overall bob movement indicates that an efficient flow-mediated rotation of either individual or aggregated erythrocytes from initially random positions toward an orientation in the shear plane characterizes flow onset.
journal_name
Biorheologyjournal_title
Biorheologyauthors
McMillan DE,Utterback NG,Lee MMdoi
10.3233/bir-1988-25407subject
Has Abstractpub_date
1988-01-01 00:00:00pages
675-84issue
4eissn
0006-355Xissn
1878-5034journal_volume
25pub_type
杂志文章相关文献
BIORHEOLOGY文献大全abstract::Although most apparent in permanently misshapen irreversibly sickled erythrocytes (ISC), biochemical and structural alterations are present in the majority of sickle cell membranes. The relationship of membrane rigidity to cell shape and its dependence upon the internal hemoglobin cytosol are not clarified. We therefo...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:1989-01-01 00:00:00
abstract::The goal of this study was to determine the duration of time that ligaments from a study group need to be loaded in order to adequately determine their collective viscoelastic behavior. Rat ligaments were subjected either to creep or stress relaxation for 1,000 s or stress relaxation for 10,000 s to compare estimates ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::An acinus is the principal secretion unit of an exocrine gland. This paper sets up a mathematical model of an acinus and examines the effect on the output of varying the operating parameters, both of the secretion mechanism and the fluid properties. Particular reference is made to acini of the pancreas. The question o...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1986-23103
更新日期:1986-01-01 00:00:00
abstract::Adhesion of monocytes (U-937 cells) along a silicone tube deployed with circular ring stents was studied to test the hypothesis that by intentionally inducing swirling flow in an endovascular stent, the adhesion of monocytes would be suppressed. The results revealed that under a normal flow condition, the flow disturb...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-120622
更新日期:2012-01-01 00:00:00
abstract::The thixotropic parameters of whole blood from 314 healthy subjects (154 women, 160 men) were measured with our modified method by Low shear 30 Rheometer and calculated according Huang's equation. This communication offered the reference range of thixotropic parameters from man and woman group. The results demonstrate...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1991-283-409
更新日期:1991-01-01 00:00:00
abstract::Ciliary metachronism and motility were examined optically in tissue cultures from frog palate epithelium as a function of extracellular ATP concentration in the range of 10(-7)-10(-3) M. The main findings were: a) upon addition of ATP the metachronal wavelength increased by a factor of up to 2. b) the velocity of the ...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1988-25309
更新日期:1988-01-01 00:00:00
abstract::The purpose of the present study was to investigate the intracellular IL-1beta production and beta1 integrins (alpha4/beta1 and alpha5/beta1) expression on chondrocytes. Chondroytes monolayer (human chondrosarcoma cell line HEM-C55) were incubated for 12, 24 and 48 hours in the presence of Tumor Necrosis Factor-alpha ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract::In this paper we shall describe new mechanical models for the deformation of the actin filament bundles in kidney microvilli and osteocytic cell processes to see whether these cellular extensions, like the stereocilia on hair cells in the inner ear, can function as mechanotransducers when subject to physiological flow...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2001-01-01 00:00:00
abstract::Aqueous solutions calf thymus DNA at three concentrations were studied by viscosity measurements at ambient pressure. A gravitational capillary viscometer and a rotating cylinder viscometer were employed. Three polycations were tested as viscosity-reducing agents with measurements from 25°C to 50°C. The most significa...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-140649
更新日期:2014-01-01 00:00:00
abstract::This study aims at quantifying the cellular mechanical properties based on a partitioning of the cytoskeleton in a cortical and a cytosolic compartments. The mechanical response of epithelial cells obtained by magnetocytometry - a micromanipulation technique which uses twisted ferromagnetic beads specifically linked t...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::The role of clustered of L-selectin receptors on the leukocyte surface is discussed in connection with the postulated velocity-dependent formation of selectin-ligand tether bonds to interpret the mechanism of leukocyte tethering to, and rolling along, the vascular endothelium. The distinct feature of this step-wise pr...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::A study using both experimental and numerical methods was conducted to determine flow dynamics in the vicinity of an end-to-end anastomosis. In vitro experiments were performed to determine the variations in the conduit cross-section at the anastomosis in specimens under static loading. The experimentally determined g...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1993-30203
更新日期:1993-03-01 00:00:00
abstract::The viscosity: shear rate relationship of whole blood is shown to be described to a good approximation by a bi-linear plot on log: log axes. This has allowed an analytical solution to be obtained which gives a full description of the flow properties of blood in rigid tubes of a size where the Fahraeus-Lindqvist effect...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1983-20204
更新日期:1983-01-01 00:00:00
abstract::Atherosclerosis is the most frequent cause of death and severe chronic disability in North America and Europe. The atherosclerosis-prone apolipoprotein E (apoE)-deficient mice contain the entire spectrum of lesions observed during atherogenesis. Significant remodelling of the artery occurs in atherosclerosis. The aim ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2007-01-01 00:00:00
abstract:BACKGROUND:Foam sclerotherapy is the process of using an aqueous foam to deliver surfactant to a varicose vein to damage vein wall endothelial cells, causing the vein to spasm, collapse and ultimately be re-absorbed into the body. Aqueous foams are complex fluids that can exhibit a significant yield stress and high eff...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-201004
更新日期:2021-01-13 00:00:00
abstract::In this work, we studied the effects of tensile strain on limb bud mesenchymal cells (MSC) cultured on a collagen type I tubular scaffold. A novel bioreactor was designed to culture the cells while subjecting the tubular scaffold to tensile stress and strain. Control samples included unseeded and MSC-seeded tubes cult...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-2009-0553
更新日期:2009-01-01 00:00:00
abstract::The separation process of blood and RBC suspensions in a hematocrit range between 0.3-0.7 was investigated with a centrifuge allowed to run at low accelerations (100 xg-1000 xg). The position of the interface between the supernatant of plasma and the RBC column was continuously recorded by a new optoelectronic measuri...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1988-251-233
更新日期:1988-01-01 00:00:00
abstract::The aim of this study was to investigate the effect of hydrostatic pressure on the expression of messenger ribonucleic acid (mRNA) for specific extracellular matrix proteins in chondrocytes. Chondrocytes obtained from bovine metatarsophalangeal joints were embedded in cylindrical 2% agarose gels. A novel experimental ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::This paper reports a novel, physiologically significant, microfluidic phenomenon generated by nanomolar concentrations of drag-reducing polymers (DRP) dissolved in flowing blood, which may explain previously demonstrated beneficial effects of DRP on tissue perfusion. In microfluidic systems used in this study, DRP add...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-2009-0543
更新日期:2009-01-01 00:00:00
abstract::Both chondrocytes and mensenchymal stem cells (MSCs) are the most used cell sources for cartilage tissue engineering. However, monolayer expansion to obtain sufficient cells leads to a rapid chondrocyte dedifferentiation and a subsequent ancillary reduced ability of MSCs to differentiate into chondrocytes, thus limiti...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2008-01-01 00:00:00
abstract::Arterial hemodynamic forces may play a role in the localization of early atherosclerotic lesions. We have been developing numerical techniques based on overset or "Chimera" type formulations to solve the Navier-Stokes equations in complex geometries simulating arterial bifurcations. This paper presents three-dimension...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.1016/s0006-355x(99)80020-1
更新日期:1998-11-01 00:00:00
abstract:BACKGROUND:Red blood cell (RBC) deformability may increase, or decrease, following application of shear stress ("shear conditioning"), depending upon the specific magnitude and duration of exposure. However, the time course of altered RBC deformability following shear remains unresolved. OBJECTIVE:We utilised shear co...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-17151
更新日期:2018-01-01 00:00:00
abstract::Pentoxifylline (PTX) has been reported to enhance the early accumulation of neutrophils at the site of Staphylococcus aureus subcutaneous infection in mice (1) and to stimulate in vitro PMN chemotaxis, particularly under dense agarose (2). Among the biochemical events contributing to chemotaxis are actin polymerizatio...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1990-273-421
更新日期:1990-01-01 00:00:00
abstract::The AC electric field-driven manipulation of suspended polarizable particles has become a major technique in micro- and nano-devices. In the present study, suspensions of cultured HeLa cells in isotonic solution were used to explore the mechanisms underlying the suspension behaviors during exposure to a uniform AC ele...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-130644
更新日期:2013-01-01 00:00:00
abstract::It has been hypothesized that bone cells have a hyaluronic acid (HA) rich glycocalyx (cell coat or pericellular matrix) and that this contributes to bone cell mechanotransduction via fluid flow. The glycocalyx of bone cells of the MC3T3-E1 osteoblastic cell line and the MLO-Y4 osteocytic cell line were characterized. ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2003-01-01 00:00:00
abstract::Shear stress-induced platelet aggregation requires von Willebrand factor (vWF), platelet glycoprotein (GP) Ib, GPIIb-IIIa, Ca2+, and adenosine diphosphate (ADP). Recent reports using vWF labeled with either 125I or fluorescein isothiocyanate (FITC) have demonstrated that in shear-fields, vWF binds to both GPIb and GPI...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.1016/S0006-355X(97)00004-8
更新日期:1997-01-01 00:00:00
abstract::The compressive stiffness of an elastic material is traditionally characterized by its Young's modulus. Young's modulus of articular cartilage can be directly measured using unconfined compression geometry by assuming the cartilage to be homogeneous and isotropic. In isotropic materials, Young's modulus can also be de...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2004-01-01 00:00:00
abstract::Stress relaxation regimes arising in a muscle subject to stepwise deformation are described on the basis of a recent phenomenological model of fully activated muscle tissue which is presented in the form of a second-order constitutive equation. It is shown that this model reproduces the qualitative form of relaxation ...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/bir-1984-21606
更新日期:1984-01-01 00:00:00
abstract::The blood flow immediately adjacent to the wall of a blood vessel or an artificial surface is of great interest. This flow defines the shear stress at the wall and is known to have a great physiological importance. The use of models is a viable method to investigate this flow. However, even in models the shear stress ...
journal_title:Biorheology
pub_type: 杂志文章
doi:
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND:Exposure to particulate air pollution is associated with an increased risk of cardiovascular disease. The mechanism by which exposure increases risk is poorly understood but could involve changes in the flow properties of blood. OBJECTIVE:The aim of this investigation was to assess the effect, in rats, of i...
journal_title:Biorheology
pub_type: 杂志文章
doi:10.3233/BIR-14027
更新日期:2014-01-01 00:00:00