BACKGROUND:Measurement of abnormal Red Blood Cell (RBC) deformability is a main indicator of Sickle Cell Anemia (SCA) and requires standardized quantification methods. Ektacytometry is commonly used to estimate the fraction of Sickled Cells (SCs) by measuring the deformability of RBCs from laser diffraction patterns under varying shear stress. In addition to estimations from model comparisons, use

BACKGROUND:Local vibration has been shown promise in improving skin blood flow and wound healing. However, the underlying mechanism of local vibration as a preconditioning intervention to alter plantar skin blood flow after walking is unclear. OBJECTIVE:The objective was to use wavelet analysis ofskin blood flow oscillations to investigate the effect of preconditioning local vibration on plantar tissues

Human blood is an excellent example of a thixo-elasto-visco-plastic (TEVP), shear-thinning fluid, with an apparent yield stress. We demonstrate a series of unique strain-controlled experiments to elucidate the evolving elastic and viscous properties of human blood and show the associated unique viscoelastic and thixotropic signatures. The experimental techniques and procedures outlined here, and the

BACKGROUND:Heart failure (HF) is a common disease globally. Ventricular assist devices (VADs) are widely used to treat HF. In contrast to the natural heart, different VADs generate different blood flow waves in the aorta. OBJECTIVE:To explore whether the different inflow rate waveforms from the ascending aorta generate far-reaching hemodynamic influences on the human aortic arch. METHODS:An aortic

BACKGROUND:In the blood flow through microvessels, platelets exhibit enhanced concentrations in the layer free of red blood cells (cell-free layer) adjacent to the vessel wall. The motion of platelets in the cell-free layer plays an essential role in their interaction with the vessel wall, and hence it affects their functions of hemostasis and thrombosis. OBJECTIVE:We aimed at estimating the diffusivity

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 effective viscosity which depend on their composition, particularly the bubble size

BACKGROUND:Numerous functions of saliva depend on its biophysical properties. Mouth rinses react with saliva and change both their own properties and properties of saliva. OBJECTIVE:The aim of this study was to define the level of mixing of artificial saliva and mouth rinses, define their viscosityand its changes at room and body temperature. METHODS:Artificial saliva, fluoride solutions, chlorhexidine

BACKGROUND:Recirculation zones within the blood vessels are known to influence the initiation and progression of atherosclerotic lesions. Quantification of recirculation parameters with accuracy remains subjective due to uncertainties in measurement of velocity and derived wall shear stress (WSS).OBJECTIVE:The primary aim is to determine recirculation height and length from PIV experiments while validating

Background:Despite improvements in treatment of ST-segment myocardial infarction (STEMI), thrombus formation in the left ventricle is still a concerning complication that may lead to systemic thromboembolism and stroke. Objectives:To evaluate the predictive value of estimated whole blood viscosity(WBV) for left ventricular thrombus development in patients surviving an acute anterior myocardial infarction

BACKGROUND:The gallbladder filling and emptying cycle controls bile flow into the duodenum. Disruption of this emptying and refilling cycle leads to bile stasis and subsequent gallstone formation. The bile flow rate is inversely proportional to its viscosity. Moreover, bile is a complex material with varying density in different people because of its diverse components. These density changes alter

BACKGROUND:Laminopathies are genetic diseases caused by mutations in the nuclear lamina. OBJECTIVE:Given the clinical impact of laminopathies, understanding mechanical properties of cells bearing lamin mutations will lead to advancement in the treatment of heart failure. METHODS:Atomic force microscopy (AFM) was used to analyze the viscoelastic behavior of neonatal rat ventricular myocyte cells expressing

BACKGROUND:Obesity-induced chronic inflammation and fibrosis in adipose tissue contributes to the progression of type 2 diabetes mellitus (DM). While fibrosis is known to induce mechanical stiffening of numerous tissue types, it is unknown whether DM is associated with alterations in adipose tissuemechanical properties. OBJECTIVE:The purpose of this study was to investigate whether DM is associated

BACKGROUND:RRx-001 is an anti-cancer immunotherapeutic that increases the sensitivity of drug resistant tumors via multiple mechanisms which involve binding to hemoglobin and enhancing nitrite reductase activity of deoxyhemoglobin. OBJECTIVE:In the present study, the effect of clinically used dosesof RRx-001 on erythrocyte deformability was examined. METHODS:A dose dependent effect of RRx-001 (1-1000

BACKGROUND:Bile, which is secreted by the liver, is essential for digesting fat and maintaining homeostasis. Although the rheology of bile is very important to its flow, its extensional viscosity has not been studied. OBJECTIVE:We investigated the stretching of bile and evaluated its extensional viscosity using a filament-breakup device. METHODS:A liquid bridge formed between the endplates of the filament-breakup

BACKGROUND:Cancerous transformation of cells affects their mechanical behavior and cytoskeleton structure. OBJECTIVE:The objective of this research is to investigate a correlation between mechanical properties and cytoskeletal structure features in cancer cell formation. METHODS:Micropipette aspiration was used to compare mechanical properties of normal (MCF10A) and cancerous (T47D) epithelial breast

BACKGROUND The endothelial (EC) surface layer (glycocalyx) has been shown to act as a barrier to transvascular exchange of solutes, and adhesion of leukocytes (WBCs) during the inflammatory process. It is a labile structure whose components are readily shed by the action of proteases and endoglycosidases. Details of shedding of specific constituents of the glycocalyx remain to be determined. OBJECTIVES

BACKGROUND The onset of many disease processes depends on the function of the endothelial cell (EC) glycocalyx (GCX) which acts as a flow-dependent barrier to cellular infiltration and molecular transport across the blood vessel wall. OBJECTIVE This review aims to examine these processes with the potential end goal of implementing GCX repair to restore EC barrier function and slow the progression of

BACKGROUND Mesenchymal stem cells (MSC) are used in therapy, often by injection into the blood. OBJECTIVE We aimed to compare the adhesive and migratory properties of MSC from umbilical cords (UCMSC), bone marrow (BMMSC) or trabecular bone (TBMSC), which might influence delivery to injured tissue. METHODS MSC were perfused through glass capillaries coated with matrix proteins, collagen or fibronectin

BACKGROUND Endothelial cells (ECs) sense the forces from blood flow through the glycocalyx, a carbohydrate rich luminal surface layer decorating most cells, and through forces transmitted through focal adhesions (FAs) on the abluminal side of the cell. OBJECTIVES This perspective paper explores a complementary hypothesis, that glycocalyx molecules on the abluminal side of the EC between the basement

BACKGROUND Previous studies on aneurysm modeling have focused on the blood rheology and vessel elasticity separately. The combined effects of blood shear thinning properties and wall elasticity need to be revealed. OBJECTIVE To provide insights on how pulsatile hemodynamics vary with blood rheology and vessel elasticity for a developed abdominal aortic aneurysm (AAA). METHOD An Arbitrary Lagrangian-Eulerian

BACKGROUND Tamarind seed polysaccharide (TSP) is used as a texturizing agent and a thickener in food and pharmaceutical products. There are no publications describing the addition of TSP to intra-articular injection formulations for arthritis. OBJECTIVE The purpose of this study was to investigate the rheology and efficacy of the formulation of TSP with hyaluronic acid (HA) as a new material for injection

The hemodynamics of the microcirculation reflect system properties of the involved components. The blood itself is a complex suspension of water, small and large molecules and different cell types. Under most conditions, its rheologic properties are dominated by the different behaviour of fluid and cellular compartments. When perfused through small-bore tubes or vessels, the suspension exhibits specific

BACKGROUND The rheology of shear thickening fluids is well characterized for many physical applications, however the literature surrounding biologically or cryobiologically compatible shear thickening fluids is less well understood. OBJECTIVE This study examined fluids consisting of corn-derived hydroxyethyl starch with a variety of sugars and cryoprotectants to characterize their shear-rate viscosity

BACKGROUND Previous studies have demonstrated that the glycosaminoglycans (GAGs) heparan sulfate (HS) and hyaluronic acid (HA) are mechanosensors for interstitial flow on cancer cells. The proteins that link the GAGs to the cancer cell for mechanotransduction, however, are not known. OBJECTIVE To assess whether the HS proteoglycan core proteins, Glypican-1 and Syndecan-1, or the HA receptor, CD44,

The endothelial glycocalyx (eGlx) constitutes the first barrier to protein in all blood vessels. This is particularly noteworthy in the renal glomerulus, an ultrafiltration barrier. Leakage of protein, such as albumin, across glomerular capillaries results in albumin in the urine (albuminuria). This is a hall mark of kidney disease and can reflect loss of blood vessel integrity in microvascular beds

BACKGROUND In order to play different roles in vascular functions as a mechanosensor to blood flows and as a barrier to transvascular exchange, the endothelial surface glycocalyx (ESG) should have an organized structure. Due to the limitations of optical and electron microscopy, the ultra-structure of ESG has not been revealed until the recent development of super-resolution optical microscopy, STORM

Diabetic retinopathy is known as a microvascular complication of hyperglycemia, with a breakdown of the blood-retinal barrier, loss of pericytes, formation of microhemorrhages, early decreases in perfusion and areas of ischemia, with the latter speculated to induce the eventual proliferative, angiogenic phase of the disease. Our animal models of diabetic retinopathy demonstrate similar decreases in

BACKGROUND The endothelial glycocalyx plays a pivotal role in regulating blood flow, filtering blood components, sensing and transducing mechanical signals. These functions are intimately related to its dynamics at the molecular level. OBJECTIVE The objective of this research is to establish the relationship between the functions of the endothelial glycocalyx and its dynamics at the molecular level

BACKGROUND Ultrastructural investigations of the endothelial glycocalyx reveal a layer adjacent to the cell surface with a structure consistent with the primary ultrafilter of vascular walls. Theory predicts this layer can be no greater than 200-300 nm thick, a result to be reconciled with observations that red cells and large macromolecules are excluded from a region 1 micrometer or more from the

BACKGROUND Isokinetic exercise is used to reduce strength imbalance and to enhance performance. OBJECTIVE The aim of this study was to investigate the acute effects of a single bout of eccentric isokinetic exercise on hemorheology (erythrocyte deformability and aggregation), total oxidant/antioxidant status (TOS/TAS) and oxidative stress index (OSI) in active individuals. METHODS The study comprises

BACKGROUND It is generally unknown if taste sensitivity is dependent upon saliva viscosity. The rheological properties of saliva result from many factors and it has been shown to behave as a non-Newtonian fluid whose viscosity decreases with increasing shear rate. Taste sensitivity may be quantitatively assayed by electro-gustometry. OBJECTIVES The aim of this work was to compare saliva rheological

BACKGROUND Hyaluronic acid (HA) is a polysaccharide present in almost all animal tissues, in which it carries out important biological functions, among them, the protection of the joints by lubricating them and dampening the tension in them. OBJECTIVE This study compares the viscoelastic properties of several commercial preparations of HA, to determine their suitability for use as viscosupplementation

BACKGROUND The venous response to elevated blood pressure (BP) is of major importance because it is closely related to the etiology of venous diseases and the competency of vein grafts. In vitro culture experiments may provide useful information on the function of vein grafts because it is easier to separate mechanical and hemodynamic effects from other systemic influences compared to in vivo experiments

BACKGROUND Previous numerical modeling studies on red blood cell (RBC) aggregation have elucidated the inverse relationship between shear rate and RBC aggregation under steady flow. However, information on the cyclic variation in RBC aggregation under pulsatile flow remains lacking. OBJECTIVE RBC aggregation was simulated to investigate the complex interrelationships among the parameters of RBC motion

BACKGROUND Developments in the production of aquacultural salmonid feeds in the last 20 years have led to extruded diets with extremely low water content and a shift from mainly marine fish based ingredients towards plant content. These changes expose the industry to the vagaries of the highly dynamic plant protein market. Resulting variations in the precise composition of aqua feeds may carry unpredictable

BACKGROUND In the microcirculation, red blood cells (RBCs) were observed to be confined to an axial stream surrounded by a marginal RBC depleted layer. This axial accumulation of RBCs is considered to arise from the RBC deformability. OBJECTIVE To quantitatively evaluate the effect of RBC deformability on their axial accumulation at a flow condition comparable to that in arterioles by developing a

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 conditioning known to increase (10 Pa) or decrease (64 Pa) RBC deformability and subsequently

BACKGROUND Age- and gender-related alterations of hemorheological parameters have not been completely elucidated to date. Experiments on older animals may give valuable information on this issue. However, the majority of rheological studies have been performed in young rodents. OBJECTIVE We aimed to investigate the influence of aging and gender on hemorheological parameters in rats. METHODS Coeval

BACKGROUND Although many studies have shown that arteries change diameter in response to chronic change in blood flow (BF), keeping wall shear stress (WSS) at physiologically normal levels, relatively little is known about the effects of flow restoration after flow reduction and also the role of vascular smooth muscle (VSM) during such a remodeling process. OBJECTIVE To elucidate the biomechanical

BACKGROUND Cartilage surface contact geometry influences the deformational behavior and stress distribution throughout the extracellular matrix (ECM) under load. OBJECTIVE To test the correlation between the mechanical and cellular response of articular cartilage when loaded with two different-sized spherical indenters under dynamic reciprocating sliding motion. METHODS Articular cartilage explants

BACKGROUND Prediction of thrombus formation at intact arterial walls under low shear flow conditions is clinically important particularly for better prognoses of embolisation in cerebral aneurysms. Although a new mathematical model for this purpose is necessary, little quantitative information has been known about platelet adhesion to intact endothelial cells. OBJECTIVE The objective of this study

BACKGROUND Reperfusion injury often occurs with therapeutic intervention addressing the arterial occlusions causing acute myocardial infarction and stroke. The no-reflow phenomenon has been ascribed to leukocyte plugging and blood vessel constriction in the microcirculation. OBJECTIVE To assess possible red cell contributions to post-thrombolytic no-reflow phenomenon. METHODS Blood clots were formed

BACKGROUND The rheological properties of sputum may influence lung function and become modified in disease. OBJECTIVE This study aimed to correlate the viscoelastic properties of sputum with clinical data on the severity of disease in patients with chronic obstructive pulmonary disease (COPD). METHODS Sputum samples from COPD patients were investigated using rheology, simple mathematical modelling

BACKGROUND In a whole blood coagulation test, the concentration of any in vitro diagnostic agent in plasma is dependent on the hematocrit level but its impact on the test result is unknown. OBJECTIVE The aim of this work was to clarify the effects of reagent concentration, particularly Ca2+, and to find a method for hematocrit estimation compatible with the coagulation test. METHODS Whole blood coagulation

BACKGROUND Acute exercise increases red blood cell-nitric oxide synthase (RBC-NOS) activation and RBC deformability but the effect of regular training remains unclear. OBJECTIVE To detect the chronic effect of enduring moderate and high intensity training on the RBC-NOS/NO pathway and to detect a relation between RBC deformability and endurance capacity. METHODS 38 healthy male subjects were randomly

BACKGROUND Arterial function is regulated by estrogen, but no consistent pattern of arterial mechanical remodeling in response to depleted estrogen levels is available. OBJECTIVE To examine long-term effects of ovariectomy (OVX) on the mechanical properties, morphology, and histological structure of the carotid artery in middle-aged rats and a potentially protective effect of Sideritis euboea extract

Transformation of circulating leukocytes from a dormant into an activated state with changing rheological properties leads to a major shift of their behavior in the microcirculation. Low levels of pseudopod formation or expression of adhesion molecules facilitate relatively free passage through microvessels while activated leukocytes with pseudopods and enhanced levels of adhesion membrane proteins

BACKGROUND Current generation mechanical circulatory assist devices are designed to minimize high shears to blood for prolonged durations to avoid hemolysis. However, red blood cells (RBC) demonstrate impaired capacity to deform when exposed to shear stress (SS) well below the "hemolytic threshold". OBJECTIVE We endeavored to identify how changes in the magnitude and duration of SS exposure alter RBC

BACKGROUND Rheology experiments have been performed on the vitreous humor, a soft gel that rests inside of the eye, to study its viscoelastic behavior and underlying macromolecular structure. A significant challenge for experimentalists is preserving the macromolecular structure when removing vitreous from in vivo conditions. OBJECTIVE We have developed a novel probe-like rheometer geometry that allows

BACKGROUND Hypercoagulability in type 2 diabetes mellitus (T2DM) patients increases their risk of cardiovascular diseases. OBJECTIVE The aim of this work was to investigate the hypercoagulation mechanism in T2DM patients in terms of circulating tissue factor (TF). METHODS Whole blood coagulation tests by damped oscillation rheometry and dielectric blood coagulometry (DBCM) were performed. RESULTS The

BACKGROUND Ultrasound elastography has been widely used to measure liver stiffness. However, the accuracy of liver viscoelasticity obtained by ultrasound elastography has not been well established. OBJECTIVE To assess the accuracy of ultrasound elastography for measuring liver viscoelasticity and compare to conventional rheometry methods. In addition, to determine if combining these two methods could

BACKGROUND Osteoarthritis is a common, localized joint disease that causes pain, stiffness and reduced mobility. The effects of osteoarthritis on the extensional rheology of synovial fluid in the knees are not fully understood and consequently require further study. OBJECTIVE The purpose of this work is to study the extensional rheology of osteoarthritic synovial fluid and to investigate a possible

BACKGROUND Osteoarthritis is a common, localized joint disease that causes pain, stiffness and reduced mobility. Osteoarthritis is particularly common in the knees. The effects of osteoarthritis on the rheology of synovial fluid in the knees are not fully understood and consequently require further study. OBJECTIVE The purpose of this study is to investigate the effects of protein content on synovial

INTRODUCTION Despite current generation mechanical assist devices being designed to limit shear stresses and minimise damage to formed elements in blood, severe secondary complications suggestive of impaired rheological functioning are still observed. At present, the precise interactions between the magnitude-duration of shear stress exposure and the deformability of red blood cells (RBC) remain largely

Backround:Possible toxic effects of hyperoxia have been reported previously. However, the number of studies investigating the influence of hyperoxia on blood cells is limited and there are no data regarding its hemorheological effects. OBJECTIVE The aim of this study was to investigate the effects of acute hyperoxia, performed in human subjects at normal atmospheric pressure, on the rheological properties

BACKGROUND Limited attention has been paid to the role of beta-adrenergic blocking agents on large artery function/structure, despite being clinically useful for treating many forms of cardiovascular disease. OBJECTIVE To assess long-term consequences of beta-blocker administration on the biomechanical properties, geometry, and histological structure of two major elastic arteries. METHODS Healthy male

The rheological properties of synovial fluid (SF) are largely attributed to the presence of high molecular weight hyaluronan (HA). However, rheological differences between SF and pure HA solutions suggest that SF proteins actively contribute towards the bulk viscoelasticity of this biological fluid. Due to various experimental challenges involved with the rheometry of low-viscosity biological fluids

BACKGROUND Systemic arterial pressure (AP) depends on two physiological variables: cardiac output (CO) and total peripheral resistance (TPR). The latter depends on vascular hindrance and blood viscosity (BV). However, the relative contributions of the vascular and rheological factors to TPR remain unclear. OBJECTIVE The aim of our work was to study the haemodynamic and haemorheologic effects of a treatment

BACKGROUND Devices gauging viscoelastic properties of blood during coagulation like the thromboelastograph support fundamental research as well as point of care needs. Associated fibrinolysis data are based on endogenous species or plasminogen activator added to a homogeneous sample prior to clot formation. Digestion in a monolithic structure differs from the physical situation of thrombolytic therapy