Download or read book Blood Filtration and Blood Cell Deformability written by John A. Dormandy and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: H. J. Meiselman From the theoretical studies of Dr. Skalak, it is clear that white cells can significantly influence the pressure-time profile of a red cell/white cell suspen sion, and that the presence of even a small amount of relatively rigid white cells can have a profound effect on the filtration pressure during the latter portion of a filtration experiment. Conversely, white cell effects, regardless of their relative rigidity, are shown to have only minimal effects during the very early (i. e. , 0-2 seconds) phases of the filtration process. Dr. Chien's experimental data support these theoretical studies, in that white cells of different mechan ical properties exhibit different pressure-time curves; pressure-time data for mixtures of leucocytes show shapes which can be predicted from the behavior of relatively homogeneous cell populations. The insensitivity of the very early portions of the filtration process to white cells is again reflected in the calculations made by Dr. Hanss. Using the nominal dilutions, white cell concentrations and the total volume of filtered cell suspension, he indicates that usually less than 1 pore out of 100 is liable to blockage by white cells. He thus concludes that, at the 1% accuracy level, initial filtration data should not be affected by mechanical pore blockage by white cells. Experimental studies by Dr. Lowe and Dr. Stuart question the WBC insensitivity of the early portion of the filtration process. Using a constant flow system, Dr.
Download or read book Blood Filtration and Blood Cell Deformability written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Blood Filtration and Blood Cell Deformability written by John A Dormandy and published by . This book was released on 1987-01-31 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Red Cell Deformability and Filterability written by John A. Dormandy and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an edited verbatim account of the proceedings of the Second London Workshop on Red Cell Filtration and Deformability, organised jointly by the Royal Society of Medicine and the Groupe de Travail sur la Filtration Erythrocytaire. The first such London Workshop was held on the occasion of the Second European Conference on Clinical Haemorheology in 1981 and its con clusions were published in an abbreviated form. The interest in blood filtration as a technique for assessing red cell deformability has continued to increase and there are now several hundred centres around the world using some form of filtration. It was, therefore, felt that the informal detailed discussions held by a small invited group of experts from many countries would be of more general interest and therefore worth publishing. This has been made possible by the continued interest and generous support of Hoechst. Spontaneous open discussion rather than formal presentations has been the hallmark of these workshops, with precirculation of all scientific data to the participants. We have attempted to preserve this flavour in editing the transcript of the proceedings. This, together with our anxiety for rapid publication, may have resulted in a less than finely polished text which may contain some in accuracies. The topics discussed were loosely structured into eight sessions, outlined in the accompanying programme.
Download or read book Blood Filtration and Blood Cell Deformability written by John Adam Dormandy and published by . This book was released on 1985 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Clinical Aspects of Blood Viscosity and Cell Deformability written by G. D. O. Lowe and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: After many years of relative neglect, the importance of study of factors governing blood flow has at last achieved recognition; in this volume are documented many of the techniques, and the basic scientific and clinical observations, which have helped to open up understanding of this highly important aspect of human physiology and pathology in recent years. The text is logically divided into five sections beginning with blood cell deformability, then moving on to theoretical consideration of blood rheology, followed by accounts of the interrelationships between rheology, blood flow and vascular occlusion. The final two sections deal with blood rheology in clinical practice and therapeutic aspects of the study of blood flow. As regards blood cell deformability (Section A), the basic problem is set out by Kiesewetter and colleagues in the first paragraph of chapter 1 (p. 3), in which they point out that whereas human erythrocytes at rest have a diameter of approxi mately 7. 5 /-tm, nutritive capillaries have diameters ranging from 3-5 /-tm, and chapters in section A give an account of the ways in which the red cell can undergo deformation to permit capillary perfusion and the maintenance of the microcirculation.
Download or read book Erythrocyte Deformability Studies by Viscometry and Filtrometry written by Sylvi Persson and published by . This book was released on 1994 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of a Micropore Pressure Filtration Measurement of Red Blood Cell Deformability written by Ann Cushley and published by . This book was released on 1982 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Relevance of Red Blood Cell Deformability in the Pathophysiology of Blood Disorders written by Sha Huang (Ph. D.) and published by . This book was released on 2014 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: Red blood cells (RBCs) play a crucial role in delivering oxygen to the body tissues. During the 120 days of their lifespan, average RBCs would circulate for approximately 500,000 times and undergo repeated deformations in small blood capillaries and splenic cords. Increased RBC clearance in the spleen is considered as one of the direct consequences of reduced RBC deformability. On the other hand, deformability is also indirectly impacting on RBC functionality through its complex connections with underlying molecular mechanisms. With the aid of microfabrication and microfluidic, we are able to perform high-throughput single cell deformability measurement. Overall, we established RBC deformability as an important biomarker for several blood related real world problems such as malaria and blood storage lesion. The ultimate goal is through our quantitative assessment of population-wide single cell deformability, we could aid in the decision-making of various clinical scenarios including drug screening and blood transfusion. Malaria is the most deadly parasitic disease affecting hundred millions of people worldwide. Infected RBCs are found to be less deformable and therefore more susceptible to splenic RBC clearance. In this thesis, we identified several clinically used anti-malarial drugs that are capable of altering RBC deformability and ultimately modifying RBC retention in spleen. We also employed a rodent malarial model, confirming the important connection of RBC deformability with splenic RBC retention and consequently malarial anemia in vivo. Blood storage lesion is another important application of our work. Taking the advantage of device high-throughput, we profiled hundreds of single RBC deformability from a large population and identified subpopulations that are less deformable. These subpopulations also exhibited higher osmotic fragility and were therefore predicted to pose higher transfusion risk according clinical standard. Furthermore, a deformability based sorting device was also developed to filter the less deformable blood subpopulations, improving overall blood quality.
Download or read book Red Cell Rheology written by M. Bessis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hemolysis during filtration through micropores studied by Chien et al. [I] showed a dependence on pressure gradient and pore diameter that, at the time of publication, did not permit an easy interpretation of the hemolytic mechanism. Acting on the assumption that thresholds of hemolysis are easier to correlate with physical forces than extents of hemolysis, we performed a series of experi ments repeating some of the conditions reported in [I] and then focusing on low L1P in order to define better the thresholds of hemolysis for several pore sizes. Employing a model of a deformed red cell shape at the pore entrance (based on micropipette observations) we related the force field in the fluid to a biaxial tension in the membrane. The threshold for lysis correlated with a membrane tension of 30 dynes/cm. This quantity is in agreement with lysis data from a number of other investigators employing a variety of mechanisms for introduc ing membrane tension. The sequence of events represented here is: a. Fluid forces and pressure gradients deform the cell into a new, elongated shape. b. Extent of deformation becomes limited by the resistance of the cell mem brane to undergo an increase in area. c. Fluid forces and pressure gradients acting on the deformed cell membrane cause an increase in biaxial tension in the membrane. d. When the strain caused by this tension causes pores to open in the membrane, the threshold for hemolysis has been reached [2].
Download or read book Filterability and Red Blood Cell Deformability written by Göteborgs universitet and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Red Cell Deformability and Filterability written by Royal Society of Medicine (United Kingdom) and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Red Cell Membrane Transport in Health and Disease written by Ingolf Bernhardt and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 761 pages. Available in PDF, EPUB and Kindle. Book excerpt: 51 worldwide leading experts in the field of erythrocyte research contributed to this first book on transport processes in red blood cells. It explains the latest findings on the basis of well-established principles, in an accessibly structured and carefully organized compilation.
Download or read book A Novel Method of Investigating Red Blood Cell Deformability written by Ir Mazkamal Mohd Zain and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Red Blood Cell Deformability on Microscale Blood Flows written by Andreas Passos and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Red Cell Deformability and Filterability written by John A Dormandy and published by . This book was released on 1983-08-31 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Red Cell Membrane written by Robert I. Weed and published by Saunders. This book was released on 1971 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:
