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- Title
- TRANSMISSION AND SCANNING ELECTRON MICROSCOPY OF AVIAN ERYTHROCYTE FUSION.
- Creator
- EMMA, DENNIS ALLEN., Florida Atlantic University
- Abstract/Description
-
Transmission electron micrographs provided evidence that fusion of erythrocytes occurred after treatment with proteolytic enzymes and polyethylene glycol (PEG). Fusion was not completed until after the elution of PEG. Scanning electron micrographs indicated that the outer membranes of adjacent cells were fused. The effects of the proteolytic enzymes employed in the cell fusion process were examined. Treatment of erythrocytes with protease alone was found superior to a combination of trypsin...
Show moreTransmission electron micrographs provided evidence that fusion of erythrocytes occurred after treatment with proteolytic enzymes and polyethylene glycol (PEG). Fusion was not completed until after the elution of PEG. Scanning electron micrographs indicated that the outer membranes of adjacent cells were fused. The effects of the proteolytic enzymes employed in the cell fusion process were examined. Treatment of erythrocytes with protease alone was found superior to a combination of trypsin and protease or to trypsin alone.
Show less - Date Issued
- 1975
- PURL
- http://purl.flvc.org/fcla/dt/13753
- Subject Headings
- Erythrocytes
- Format
- Document (PDF)
- Title
- A COMPARATIVE STUDY OF METHODS OF SOMATIC CELL FUSION.
- Creator
- GALLA, JAN DAVID, Florida Atlantic University
- Abstract/Description
-
The effectiveness of polyethylene glycol as a fusogenic agent tor avian erythrocytes was evaluated. Parameters affecting the efficiency of fusion included number of pre-fusion washes, age of cells, length of exposure to enzyme solutions at varied pH values, composition of wash solutions and molecular weights of polyethylene glycol. Fusion was measured as the percentage of visible polykaryons. Maximal fusion obtained using polyethylene glycol was approximately 60-70%. Other methods of cell...
Show moreThe effectiveness of polyethylene glycol as a fusogenic agent tor avian erythrocytes was evaluated. Parameters affecting the efficiency of fusion included number of pre-fusion washes, age of cells, length of exposure to enzyme solutions at varied pH values, composition of wash solutions and molecular weights of polyethylene glycol. Fusion was measured as the percentage of visible polykaryons. Maximal fusion obtained using polyethylene glycol was approximately 60-70%. Other methods of cell fusion (lysolecithin, Sendai virus, high calcium concentration at high pH) were compared to polyethylene glycol. All other means yielded lesser amounts of fused products. A photographic comparison of the various methods is presented, and possible mechanisms of fusion are discussed.
Show less - Date Issued
- 1975
- PURL
- http://purl.flvc.org/fcla/dt/13703
- Subject Headings
- Cell hybridization, Somatic hybrids, Erythrocytes
- Format
- Document (PDF)
- Title
- A comparative study of animal erythrocyte agglutinins from marine algae.
- Creator
- Chiles, Thomas C., Bird, Kimon T., Harbor Branch Oceanographic Institute
- Date Issued
- 1989
- PURL
- http://purl.flvc.org/FCLA/DT/3353838
- Subject Headings
- Marine algae, Agglutinins, Erythrocytes, Glycoproteins, Polysaccharides, Monosaccharides, Comparative Study
- Format
- Document (PDF)
- Title
- ELECTRICAL IMPEDANCE SENSING OF ERYTHROCYTES AND CYTOADHESION.
- Creator
- Liu, Jia, Du, Sarah E., Florida Atlantic University, Department of Ocean and Mechanical Engineering, College of Engineering and Computer Science
- Abstract/Description
-
Electrical impedance of cells is a sensitive indicator of changes in cellular structure and biophysical characteristics. Integration of electrical impedance sensing in microfluidics can be a useful tool for characterization of blood cells for their disease state, such as sickle cell disease and malaria. The first part of this dissertation presents application of a microfluidics-based electrical impedance sensor for the study of sickle cell disease. Dynamic cell sickling-unsickling process of...
Show moreElectrical impedance of cells is a sensitive indicator of changes in cellular structure and biophysical characteristics. Integration of electrical impedance sensing in microfluidics can be a useful tool for characterization of blood cells for their disease state, such as sickle cell disease and malaria. The first part of this dissertation presents application of a microfluidics-based electrical impedance sensor for the study of sickle cell disease. Dynamic cell sickling-unsickling process of blood cells in response to cyclic hypoxia was measured. Strong correlation was found between the electrical impedance data and patients’ hematological parameters such as levels of sickle hemoglobin and fetal hemoglobin. In addition, application of electrical impedance spectroscopy in narrow microfluidic channel was used for label-free flow cytometry and non-invasive assay of single sickle cells under controlled oxygen level. We demonstrate the capability of this new technique in differentiating normal red blood cells from sickle cells, as well as sickled cells from unsickled cells, using normoxic and hypoxic conditions. The second part of this dissertation reports an application of electrical impedance sensing for the study of placental malaria. Testing conditions were optimized so that electrical impedance can be used for real time monitoring of different cellular and molecular level variations in this in vitro model of placental malaria. Impedance characteristics of cell proliferation, syncytial fusion and long-term response of BeWo cells to adhesion of infected erythrocytes were obtained and related to the immunostaining results and inflammatory cytokines measurements. Comparing to the conventional optical microscope-based methods, electrical impedance sensing technique can provide a label-free, real-time monitoring tool to study erythrocytes and cytoadhesion, and can further be extended to other disease models and cell types.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013389
- Subject Headings
- Microfluidics, Erythrocytes, Electric Impedance, Sickle cell disease, Malaria, Cell Adhesion
- Format
- Document (PDF)
- Title
- MECHANICAL FATIGUE TESTING OF HUMAN RED BLOOD CELLS USING THE ELECTRO-DEFORMATION METHOD.
- Creator
- Qiang, Yuhao, Du, Sarah, Florida Atlantic University, College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
- Abstract/Description
-
Human red blood cells (RBCs) must undergo severe deformation to pass through narrow capillaries and submicronic splenic slits for several hundred thousand times in their normal lifespan. Studies of RBC biomechanics have been mainly focused on cell deformability measured from a single application of stress using classical biomechanical techniques, such as optical tweezers and micropipette aspiration. Mechanical fatigue effect on RBCs under cyclic loadings of stress that contributes to the...
Show moreHuman red blood cells (RBCs) must undergo severe deformation to pass through narrow capillaries and submicronic splenic slits for several hundred thousand times in their normal lifespan. Studies of RBC biomechanics have been mainly focused on cell deformability measured from a single application of stress using classical biomechanical techniques, such as optical tweezers and micropipette aspiration. Mechanical fatigue effect on RBCs under cyclic loadings of stress that contributes to the membrane failure in blood circulation is not fully understood. This research developed a new experimental method for mechanical fatigue testing of RBCs using amplitude-modulated electro-deformation technique. Biomechanical parameters of individually tracked RBCs show strong correlations with the number of the loading cycles. Effects of loading configurations on the cellular fatigue behavior of RBCs is further studied. The results uniquely establish the important role of mechanical fatigue in influencing physical properties of biological cells. They further provide insights into the accumulated membrane damage during blood circulation, paving the way for further investigations of the eventual failure of RBCs in various hemolytic pathologies.
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013340
- Subject Headings
- Red blood cells, Erythrocytes--Deformability, Biomechanics--Research--Methodology
- Format
- Document (PDF)
- Title
- STUDIES ON POLYETHYLENE GLYCOL-MEDIATED AGGREGATION AND FUSION OF AVIAN ERYTHROCYTES.
- Creator
- BATCHELOR, ROGER ALLEN., Florida Atlantic University
- Abstract/Description
-
Polyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG,...
Show morePolyethylene glycol (PEG)-induced aggregation, hemolysis and fusion of chicken red blood ceils (CRBC's) was studied in relation to the following parameters: osmotic pressure, polymer concentration, ionic strength, electrolyte species, surface charge removal and glutaraldehyde fixation. Indirect evidence indicated that osmotic pressure does not play a primary role in aggregation and fusion of red blood cells. Maximum aggregation and fusion was obtained in solutions of 20 and 40% PEG, respectively. In contrast, hemolysis increased almost linearily with PEG concentration. The negative electrostatic charge due to the presence of sialic acid on the membrane surface was found to be the primary factor affecting aggregation, hemolysis and fusion. Removal of the charge by neuraminidase or screening with cations enhanced aggregation and fusion while inhibiting hemolysis. The inhibition of aggregation by glutaraldehyde fixation, and hemolysis and fusion results not attributed to surface charges, are discussed in terms of intramembrane interactions with PEG.
Show less - Date Issued
- 1977
- PURL
- http://purl.flvc.org/fcla/dt/13893
- Subject Headings
- Cell hybridization, Erythrocytes, Hemolysis and hemolysins, Membrane fusion
- Format
- Document (PDF)
- Title
- SUPPORTED ERYTHROCYTE MEMBRANES ON PIEZOELECTRIC SENSORS FOR STUDYING THE INTERACTIONS BETWEEN NANOPARTICLES AND SURFACES OF RED BLOOD CELLS.
- Creator
- Islam, Tanaz, Yi, Peng, Florida Atlantic University, Department of Civil, Environmental and Geomatics Engineering, College of Engineering and Computer Science
- Abstract/Description
-
The Supported red blood cell membrane (SRBCm) was developed on a piezoelectric sensor to study the attachment of nanoparticles to erythrocyte surfaces. A well-dispersed colloidal suspension of fragments of RBCm was prepared from whole blood, and characterized thoroughly using cryogenic transmission electron microscopy, dynamic light scattering, and zeta potential analysis. To develop SRBCm, RBCm fragments were immobilized onthe sensor in a quartz crystal microbalance with dissipation...
Show moreThe Supported red blood cell membrane (SRBCm) was developed on a piezoelectric sensor to study the attachment of nanoparticles to erythrocyte surfaces. A well-dispersed colloidal suspension of fragments of RBCm was prepared from whole blood, and characterized thoroughly using cryogenic transmission electron microscopy, dynamic light scattering, and zeta potential analysis. To develop SRBCm, RBCm fragments were immobilized onthe sensor in a quartz crystal microbalance with dissipation monitoring system. A complete monolayer of flattened fragments of RBCm was formed on the positively charged surface of the piezoelectric sensor in 1 mM NaCl and 0.2 mM NaHCO3 at pH 7.1. The surface morphology of SRBCm was characterized via atomic force microscopy. The even distribution of surface proteins expressed on erythrocytes was found on SRBCm through indirect immunofluorescence microscopy. The attachment efficiencies of model nanoparticles, e.g. hematite nanoparticles and carboxylated polystyrene nanoparticles, on the SRBCm were quantified using a classic methodology. KEYWORDS: Supported erythrocyte membrane, piezoelectric sensor, phospholipid bilayers, nanoparticles
Show less - Date Issued
- 2019
- PURL
- http://purl.flvc.org/fau/fd/FA00013383
- Subject Headings
- Erythrocyte Membrane, Piezoelectric polymer biosensors, Nanoparticles, Phospholipid bilayers, Bilayer lipid membranes
- Format
- Document (PDF)
- Title
- Microfluidic Electrical Impedance Spectroscopy for Blood Analysis.
- Creator
- Rikhtehgaran, Samaneh, Wille, Luc T., Du, E., Florida Atlantic University, Department of Physics, Charles E. Schmidt College of Science
- Abstract/Description
-
The study of the electrical properties of red blood cells (RBCs) plays a crucial role in advancing our understanding of human health. As RBCs age, they undergo changes that affect hemorheology and blood microcirculation, which have far-reaching implications for disease research. Furthermore, the shortage of RBC storage units can be a major issue for patients, underscoring the importance of characterizing RBC aging with respect to cell densities. In individuals with abnormal hemoglobin disease...
Show moreThe study of the electrical properties of red blood cells (RBCs) plays a crucial role in advancing our understanding of human health. As RBCs age, they undergo changes that affect hemorheology and blood microcirculation, which have far-reaching implications for disease research. Furthermore, the shortage of RBC storage units can be a major issue for patients, underscoring the importance of characterizing RBC aging with respect to cell densities. In individuals with abnormal hemoglobin disease, alterations in hemoglobin and its functionality can modify the volume and density of RBCs, making their study even more crucial. To this end, our aim is to investigate the impedance alterations of RBCs after distributing them into different layers based on their densities. We have developed a novel method for non-invasive, rapid, and real-time single-cell analysis of RBCs. Our approach involves the use of electrical impedance spectroscopy (EIS) to study the cells after performing cell fractionation. Our studies indicate an increasing trend for RBC resistance and a decreasing trend for the cell membrane as the density of the layer increases. Additionally, we have developed a method for extracting hemoglobin with high purity from fresh samples of RBCs. By passing lysed RBCs through ultrafiltration devices and removing debris and membranes, we were able to isolate hemoglobin. Using the EIS technique, we studied the alterations of impedance over a frequency range, obtaining valuable insight into the electrical properties of hemoglobin.
Show less - Date Issued
- 2023
- PURL
- http://purl.flvc.org/fau/fd/FA00014223
- Subject Headings
- Blood--Analysis, Erythrocytes--Aging, Hemorheology, Electrical impedance spectroscopy, Microfluidics
- Format
- Document (PDF)