Rheological models for testing drugs that modify erythrocyte deformability by Yousif Yahia Bilto

Cover of: Rheological models for testing drugs that modify erythrocyte deformability | Yousif Yahia Bilto

Published by University of Birmingham in Birmingham .

Written in English

Read online

Edition Notes

Thesis (Ph.D.) - University of Birmingham, Dept of Haematology.

Book details

Statementby Yousif Yahia Bilto.
ID Numbers
Open LibraryOL13902382M

Download Rheological models for testing drugs that modify erythrocyte deformability

The experimental determination of the rheological behaviour of materials is called rheometry. The object of haemorheology is the application of rheology to the study of flow properties of blood and its formed elements, and the coupling of blood and the blood vessels in living by: Effects of an Amphipathic Drug on the Rheological Properties of the Cell Membrane But can it modify the mechanical properties of the membrane.

In the present work it was observed that sodium thiopental affected the membrane rheological properties by improving erythrocyte deformability; this effect resulted from a reduction of both the.

Erythrocyte aggregation indices did not change after swimming in water at 4°C whereas erythrocyte deformability increased at shear stress 1,13 [Pa] 96 [Pa]. The deformability of erythrocytes and their viscosity index which can pass ahead of the shifts in other parameters characterizing the hemocoagulative and rheological properties of blood are changed.

A conclusion is drawn that the parameters of the erythrocyte deformability and viscosity can be an additional criteria of the adequacy of therapy Author: Bessmel'tsev Ss, Tsarapkin Im, Fedorova Zd. Rheological properties of blood were studied in subjects with high physical activity (athletes).

It was found that the whole blood viscosity decreased under conditions of relative rest. The use of the concept of hemorheological profiles made it possible to reveal different profiles in subjects exposed to different courses of training by: 3.

Abstract. Using a laser diffraction technique, we have studied factors that influence the deformability of erythrocytes. Variations in suspending medium osmolality and applied shear stress were employed to isolate the individual contributions to Rheological models for testing drugs that modify erythrocyte deformability book cell deformability of internal viscosity, surface area-to-volume ratio, and viscoelastic properties of the by: Adoption of these guidelines should improve comparability between rheological laboratories and increase the reliability of rheological tests.

Keywords: Rheology, Blood viscosity, Erythrocyte deformability. DOI: /CH Journal: Clinical Hemorheology and Cited by: A higher than normal glucose concentration in a suspending medium may produce non-enzymatic glycosylation of erythrocyte proteins.

This process can modify the viscoelastic properties of erythrocytes. In this paper, we studied the possible relationship between glucose concentration in a suspending medium and erythrocyte rheological by:   Hemolysis associated with SWNT exposure.

Hemolysis does not rely on elapsed time because the hemolysis process is completed within 5 min and similar results were also reported [].Figure 1 shows hemoglobin release from erythrocytes exposed to two SWNT samples with different dispersion states.

For individual SWNT samples, the hemolysis rates of RBCs exposed to or μg/mL Cited by: 3. For non-Newtonian rheological models necessary to describe some specific flow processes, such as clotting, or sickle cell diseases, or more generally flow in capillaries, we refer, e.g., to [].

This distinction is purely artificial as undoubtedly one of the most important determinants of whole-blood viscosity, particularly at high shear rates, is the ability of individual red cells to deform.

This chapter will, however, only consider the action of drugs specifically on erythrocyte deformability. angina on some rheological properties of the erythrocytes. Our study revealed that atherogenic lipids increased erythrocyte’s aggregation, but level of high density lipoproteins has no affect on the aggregation.

Erythrocyte deformability of red blood cells was not associated with the plasma lipid profile. Rheological Testing of Foods. Rheology is the science concerned with the deformation and flow of matter.

Most rheological tests involve applying a force to a material and measuring its flow or change in shape. Rheology is important in a number of different areas of food science.

Many of the textural properties that human beings perceive when they consume foods are largely rheological in. Recent study comparing the blood count and rheological properties of blood before and after outpatient cardiac rehabilitation program in CAD patients showed no changes in erythrocyte deformability.

lead to the possible employment of rheological parameters and models to optimize topical drug delivery from dermato-logical formulations.

Due to their paramount importance, the rheological properties of carbomer gels have extensively been investigated as a function of concentration, pH, and cross-link density (7,9–11).File Size: KB.

Experimental Cell Research 58 () STUDIES ON CELL DEFORMABILITY Some Rheological Considerations L. WEISS and K. CLEMENT Department of Experimental Pathology, Roswell Park Memorial Institute, Buffalo, N.

USA SUMMARY The negative pressures required to produce a hemispherical deformation of mammalian cells into micropipettes has been measured when Cited by: rheological properties of blood Rheology is a specialized part of fluid mechanics and is concerned principally with non-Newtonian and viscoelastic substances.

A Newtonian liquid is one in which the viscosity, at fixed temperature and pressure, is independent of the shear stress. In this study, an apparent Young's modulus and a time constant for the recovery of erythrocyte shape following uniaxial stretching are proposed as deformability indices.

When an erythrocyte was pulled horizontally on opposite ends using two micropipettes, tensile stress and strain were measured, and an apparent Young's modulus was calculated.

Hemoglobin solutions prepared from hemolyzed human erythrocyte packs have Newtonian flow properties. Diluted solutions are also Newtonian. All solutions have a viscosity lower than the apparent viscosity of erythrocyte suspensions of equal oxygen-carrying capacity.

The presence of cell debris in hemoglobin solutions causes non-Newtonian (pseudoplastic or rheopectic) flow behavior. Effect of picroside II on erythrocyte deformability and lipid peroxidation in rats subjected to hind limb ischemia reperfusion injury Faruk Metin Çomu,1 Yiğit Kılıç,2 Abdullah Özer,2 Mehmet Kirişçi,3 Ali Doğan Dursun,4 Tolga Tatar,2 Mustafa Hakan Zor,2 Hakan Kartal,2 Ayşegül Küçük,5 Hakan Boyunağa,6 Mustafa Arslan71Department of Physiology, Kirikkale University Medical Faculty.

A capillary rheometer is a specific type of rheometer which computes rheological parameters from pressure measurements taken prior to the flow of material through a small capillary. The rheometer typically uses a speed controlled piston to drive material from a heated bore through a small (1mm diameter typically) capillary.

elements and their interactions leads to signi cant changes in the blood rheological properties and reliable measurements need to be performed to derive appropriate microstructural models. Otherwise, depending on the size of the blood vessels and the ow behaviour, it is approximated as a Navier-Stokes uid or as a non-Newtonian by: ulgel formulations based on different gelling agent I.I.

Berdey, O.I. Voyt Abstract This study was conducted to determine the viscoelastic properties and rheological characterization of some emulgel formulations that includes gelling agents from different groups: natural, synthetic and : I.I.

Berdey, O.I. Voyt. Suspensions of healthy and pathological red blood cells (RBC) flowing in microfluidic devices are frequently used to perform in vitro blood experiments for a better understanding of human microcirculation hemodynamic phenomena. This work reports the development of particulate viscoelastic analogue fluids able to mimic the rheological and hemorheological behavior of pathological RBC Cited by: Invitro particulate analogue fluids for experimental studies of rheological and hemorheological behavior of glucose-rich RBC suspensions Diana Pinho,1,2 Laura Campo-Deano,~ 2 Rui Lima,2,3 and Fernando T.

Pinho2 1ESTiG, Polytechnic Institute of Braganc¸a, C. Sta Apolonia, Braganc¸a, Portugal 2CEFT, DEMec, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias. rheological properties are very sensitive to certain aspect of structure and they are simpler to use than analytical methods, such as nuclear magnetic resonance.

Secondly, it is the rheological properties that govern the flow be-haviour of polymers when they are processed in the mol-ten state. Considering the structures of polymers by. Understanding cell–nanoparticle interactions is critical to developing effective nanosized drug delivery systems.

Nanoparticles have already advanced the treatment of several challenging conditions including cancer and human immunodeficiency virus (HIV), yet still hold the potential to improve drug delivery to elusive target sites.

Even though most nanoparticles will encounter blood at a Cited by: 1. Rheological characterization of each bio-modified gilsonite (BMG) sample was then conducted to investigate the performance.

Results indicate that BMG samples show an improved high temperature performance as well as comparable low temperature and adhesion compared to PG In some cases, BMG samples show even better performance at low. Predicting Performance of Pharmaceutical Lotions Through Rheological Characterization Keywords: cosmetics, pharmaceutical, oscillatory testing, flow testing, creep, creep-recovery, sensory panel PROBLEM A pharmaceutical company wanted to compare the “spreadability” of two lotions to determine the effects of formulation differences.

The Influence of Thickeners on Rheological and Sensory Properties of Cosmetic Lotions – – choice of the corresponding absolute or universal scales, and suitable choice of a professional panel (expensive). Gilbert et al. [3, 4] have presented a method of Spectrum Descriptive Analysis reflecting an accurate sensory description of.

Review. Rheological properties of biological materials C. Verdier a, J. Etienne, A. Duperrayb,c, L. Preziosid aLaboratoire de Spectrometrie´ Physique, avenue de la Physique BP87, Saint-Martin d’Her` es cedex, France bINSERM, U, Grenoble, France cUniversite´ Joseph Fourier-Grenoble I, Faculte´ de Medecine´, Institut d’oncologie et developpement´ Albert Bonniot et Author: Claude Verdier, Jocelyn Etienne, Alain Duperray, Luigi Preziosi.

tory testing Test on the prepared samples were conducted according to ASTM [13] method to characterize the properties of PMBs. The different percentage of polymer concentration provides a wider range of results which helps in analysing each type of the polymer blend at.

SWNT concentration. Rheological measurements showed good dispersion of SWNTs in uncrosslinked PPF at low concentrations of wt% and SWNT aggregation for higher concentrations for all formulations examined.

Mechanical testing demonstrated significant reinforcement in the compressive and flexural mechanical properties of crosslinked. LABORATORY EVALUATION OF RHEOLOGICAL BEHAVIOR OF AN ASPHALT CONCRETE CONTAINING AN SBR ELASTOMETER.

The subject of this paper is the influence of synthetic rubber (an elastomer styrene-butadiene rubber (SBR)) on the rheological behavior of asphalt concrete. The viscoelastic functions of a wearing course asphalt concrete with and without rubber.

Formulation, Characterization, and Stability of Protein Drugs: Case Histories (Pharmaceutical Biotechnology (9)): Medicine & Health Science Books @ mat: Hardcover.

Objective: The purpose of this study was to investigate the in vitro effects of low-level laser radiation (LLLR) on some rheological factors of the human blood, such as complete blood count (CBC) parameters and blood sedimentation rate (BSR).

We were mainly concerned with the alterations caused by LLLR action on blood cells (erythrocytes and. The curing reaction of the bismaleimide resin system was analyzed by FT-IR spectroscopy and differential scanning calorimetry, and the curing reaction kinetics parameters were characterized.

Otherwise the rheological behavior of the bismaleimide resin was studied through tracking the changes of the resin viscosity with reaction temperature and time by using a rotatory by: 1. intrinsic dissolution rate of drugs. Human gastric fluid (HGF) consists mainly of water (98%) and the other components are hydrochloride acid, salts, mucus, proteins, phospholipids and enzymes.

Bile Polymer Selection for Simulation of Rheological Properties of Human Gastric Fluid. some derived indexes; we also evaluated erythrocyte deformability by diffractometry at the shear stresses of 6, 12, 30, 60 Pa. RESULTS: In MM patients we observed, as expected, a decrease in hematocrit and a marked increase in PV, but also a significant reduction of the erythrocyte deformability.

A low erythrocyte deformability was. Rheological Characterization of Liquid-to-Solid Transitions in Bulk Polyelectrolyte Complexes Yalin Liu,a Brian Momani, a H. Henning Winter,a Sarah L. Perry* a Polyelectrolyte complexation has long been known to result in both liquid and solid complexes.

However, the exact nature of the liquid-to-solid transition remains an open by:. Bio mastic asphalt rheological properties: The rheological properties of the blend was then evaluated by using the Dynamic Shear Rheometer (DSR) which is Designed to precisely measure stresses and strains of various materials under oscillatory, steady shear and repeated loads at .rheological characterization is needed for identification of performance guaranteed products and also to tailor drug delivery systems with desired rheological characteristics.

Towards these goals, in the present study, efforts were taken in unveiling the rheological profile of Carbopol hydrogel by subjecting to flow, frequency sweep, creep.The rheological analysis of all the materials was done using a Thermo Haake Rheoflixer MTI[R] capillary rheometer.

The temperature used in the rheometer was [degrees]C, which is well within the recommended range of the manufacturer. The shearing speeds used in the study were in the range to 10, [].

6146 views Monday, November 9, 2020