Plasmodium falciparum malaria merozoites require erythrocyte sialic acid for optimal invasion of human erythrocytes. Since mouse erythrocytes have the form of sialic acid found on human erythrocytes (N-acetyl neuraminic acid), mouse erythrocytes were tested for invasion in vitro. The Camp and 7G8 strains of P. falciparum invaded mouse erythrocytes at 17-45% of the invasion rate of human erythrocytes. Newly invaded mouse erythrocytes morphologically resembled parasitized human erythrocytes as shown on Giemsa-stained blood films and by electron microscopy. The rim of parasitized mouse erythrocytes contained the P. falciparum 155-kD protein, which is on the rim of ring-infected human erythrocytes. Camp but not 7G8 invaded rat erythrocytes, indicating receptor heterogeneity. These data suggest that it may be possible to adapt the asexual erythrocytic stage of P. falciparum to rodents. The development of a rodent model of P. falciparum malaria could facilitate vaccine development. ...
Our reports show Osmolarity was restored and a culture containing 30% lysed uninfected erythrocytes and 70% intact uninfected erythrocytes clearly that directional flight action and time compensated sunshine compass orientation persist reproductively active Osmolarity was restored and a culture containing 30% lysed uninfected erythrocytes and 70% intact uninfected erythrocytes migrants, but persistent time compensation experienced not been revealed earlier. It is Osmolarity was restored and a culture containing 30% lysed uninfected erythrocytes and 70% intact uninfected erythrocytes nonetheless feasible that JH deficiency is involved in the induction of directed flight for sun compass orientation, but it is distinct from our results that persistent JH deficiency is not required for upkeep. More analysis of the forty genes we have discovered in monarchs will very likely offer novel insights into their personal and or collective significance for migration and the brain alterations needed to ...
1. Erythrocyte sodium, sodium transport (ouabain-sensitive efflux rate of sodium, oMosNa, and ouabain-sensitive efflux rate constant of sodium, oMosNa), sodium-potassium activated ouabain-sensitive adenosine triphosphatase (Na+, K+-ATPase) activity and [3H]ouabain-binding capacity were measured in 15 patients with chronic renal failure and in 10 healthy subjects.. 2. As a group, patients with chronic renal failure had a lower erythrocyte sodium and oMosNa compared with healthy subjects.. 3. When patients were divided according to their erythrocyte sodium (greater or less than 4 mmol/kg of cells), in the group of patients whose erythrocyte sodium was less than 4 mmol/kg of cells (group A) the oMosNa was higher than that in healthy subjects and the oMosNa, Na+, K+-ATPase activity and [3H]ouabain-binding capacity were the same as those in healthy subjects. In the subgroup of patients with renal failure whose erythrocyte sodium content was greater than 4 mmol/kg of cells (group B) the oMosNa was ...
Sequestration of malaria-infected erythrocytes in the peripheral circulation has been associated with the virulence of Plasmodium falciparum. Defining the adhesive phenotypes of infected erythrocytes may therefore help us to understand how severe disease is caused and how to prevent or treat it. We have previously shown that malaria-infected erythrocytes may form apparent autoagglutinates of infected erythrocytes. Here we show that such autoagglutination of a laboratory line of P. falciparum is mediated by platelets and that the formation of clumps of infected erythrocytes and platelets requires expression of the platelet surface glycoprotein CD36. Platelet-dependent clumping is a distinct adhesive phenotype, expressed by some but not all CD36-binding parasite lines, and is common in field isolates of P. falciparum. Finally, we have established that platelet-mediated clumping is strongly associated with severe malaria. Precise definition of the molecular basis of this intriguing adhesive phenotype may
Background Sickle cell trait (HbAS) confers partial protection against malaria by reducing the adhesion of Plasmodium falciparum-infected erythrocytes to host receptors, but little is known about its potential protection against placental malaria. Methods Using flow cytometry, we assessed the recognition of HbAA and HbAS VAR2CSA-expressing infected erythrocytes, by plasma from 159 Beninese pregnant women with either HbAA (normal) or HbAS. Using multivariate linear models adjusted for gravidity, parasite infection at delivery, glucose-6-phosphate dehydrogenase deficiency, and α-thalassemia carriage, we observed significantly reduced cell surface antibody binding of HbAS-infected erythrocytes by plasma from HbAS compared with HbAA women (P , 10-3). Results The difference in cell surface antibody binding was only observed when infected erythrocytes and plasma were associated according to the same hemoglobin genotype. Similar levels of VAR2CSA-specific antibody were measured by enzyme-linked ...
Fishes, amphibia and reptiles, the ectothermic vertebrates, are hosts for a variety of intraerythrocytic parasites including protists, prokaryotes, viruses and structures of uncertain status. These parasites may experience host temperature fluctuations, host reproductive strategies, population genetics, host habitat and migratory behaviour quite unlike those of endothermic hosts. Few blood infections of fishes, amphibia and reptiles have proven pathogenicity, in contrast to the many intraerythrocytic parasites of mammals and some birds which harm their hosts. Although not given the attention afforded to intraerythrocytic parasites of endotherms, those of ectotherms have been studied for more than a century. This review reports on the diversity, general biology and phylogeny of intraerythrocytic parasites of ectotherms. The existence of taxonomic confusion is emphasized and the main taxonomic features of most of the 23 better characterized genera, particularly the kinetoplastid and apicomplexan ...
PPFWE : All porphyrin tests on erythrocytes can be performed on 1 tube.   Patient Preparation: Patient should abstain from alcohol for 24 hours. Collection Container/Tube: Preferred: Green top (sodium heparin) Acceptable: Dark blue top (metal free heparin) or green top (lithium heparin) Submission Container/Tube: Plastic vial Specimen Volume: Washed erythrocyte suspension Collection Instructions: Collect and process whole blood specimen as follows: 1. Transfer entire specimen to a 12-mL graduated centrifuge tube. 2. Centrifuge specimen for 10 minutes at 2000 rpm. 3. Record volume of packed cells and the total volume of the specimen. 4. Discard supernatant plasma. 5. Wash packed erythrocytes 2 times by resuspension of at least an equal amount of cold 0.9% saline, mix, and centrifuge for 5 minutes at 2000 rpm, discarding supernatant after each washing. 6. Resuspend packed cells to the original total volume with 0.9% saline. Invert specimen gently to mix. 7. Transfer washed erythrocytes
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NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Part I: Protein Synthesis During Chicken Erthrocytes Differentiation. It was the major purpose of this research to study changes of protein synthesis during chicken erythrocyte differentiation. In Chapter 1, erythrocytes from the blood of normal and anemic birds were fractionated by buoyant density centrifugation in bovine serum albumin gradients. It is shown that this procedure fractionates the erythroid cells according to their physiological maturity. Reduction of RNA synthesis, RNA content, and protein synthesis are shown to accompany cell maturation. Inhibition of RNA synthesis with actinomycin D does not affect hemoglobin synthesis in erythroid cells from anemic birds. The two hemoglobins, present within single chicken erythrocytes, appear to be synthesized in constant ratio throughout eiythropoiesis, suggesting that the factors involved (at the genetic and translation levels) ...
The hemoglobins S and C protect carriers from severe Plasmodium falciparum malaria. Here, we found that these hemoglobinopathies affected the trafficking system that directs parasite-encoded proteins to the surface of infected erythrocytes. Cryoelectron tomography revealed that the parasite generated a host-derived actin cytoskeleton within the cytoplasm of wild-type red blood cells that connected the Maurers clefts with the host cell membrane and to which transport vesicles were attached. The actin cytoskeleton and the Maurers clefts were aberrant in erythrocytes containing hemoglobin S or C. Hemoglobin oxidation products, enriched in hemoglobin S and C erythrocytes, inhibited actin polymerization in vitro and may account for the protective role in malaria. ...
Eremin, O and Binns, R M., Mouse red blood cell rosettes: human b and some t lymphocytes express receptors for mouse erythroucytes in the presence of ficoll. (1982). Subject Strain Bibliography 1982. 3293 ...
In physiological circumstances, erythrocyte aging leads to binding of autologous IgG followed by recognition and removal through phagocytosis, mainly by Kupffer cells in the liver. This process is triggered by the appearance of a senescent erythrocyte-specific antigen. The functional and structural characteristics of senescent erythrocytes strongly suggest that this antigen originates on band 3, probably by calcium-induced proteolysis. Generation of vesicles enriched in denatured hemoglobin is an integral part of the erythrocyte aging process. These vesicles are also removed by Kupffer cells, with a major role for exposure of phosphatidylserine. Moreover, senescent erythrocyte-specific antigens are present on vesicles. Thus, vesicles and senescent erythrocytes may be recognized and removed through the same signals. These and other, recent data support the theory that erythrocyte aging is a form of apoptosis that is concentrated in the cell membrane, and provide the context for future studies on ...
Red blood cells, or erythrocytes, travel through circulating blood carrying oxygen to body tissues and organs while removing waste. These blood cells make up the largest part of the blood system.. As the red blood cells in blood travel through the lungs, oxygen molecules from the lungs attach to the hemoglobin, a protein in the blood cells that contains iron. The oxygen is then released to tissues and organs, and the hemoglobin bonds with carbon dioxide and other waste gases. These waste products are transported away and removed as blood continues to circulate.. Millions of red blood cells are contained in a single drop of blood. Red blood cells are constantly being produced in the bone marrow to replenish those that gradually wear out and die. The average life of a red blood cell is about 120 days.. A significant decrease in the number of red blood cells causes anemia and shortness of breath. ...
Stabilized human and animal erythrocytes are a suspension of stabilized erythrocytes of humans and mammals, obtained from erythrocyte mass of humans or whole blood of mammals.. The volume of erythrocytes and their number are preserved throughout the product validity period with the minimal deviations from the passport values, due to the method of effective stabilization developed by our company.. It is possible to obtain stabilized erythrocytes with different antigenic status (ABO system, Rh-factor, other anti-gene systems of human and mammal blood).. Stabilized erythrocytes can be used in the production of control materials for in vitro diagnostics, hematological research, for example, during the production of hematological controls for automatic hematological analyzers, including the possibility of determining normoblasts and reticulocytes.. Storage temperature: +2 +8°С.. Validity period: not less than 180 days.. Each series of stabilized erythrocytes is accompanied by a passport, with ...
Normal red blood cell (erythrocyte) and red blood cell infected with the malaria parasite (Plasmodium falciparum, schizont stage), animated coloured scanning electron micrograph (SEM). The upper right red blood cell there is a large protrusion that is the schizont stage of the malaria parasite that is dividing and growing in the red blood cell. Malaria is caused by Plasmodium spp., protozoa. It is spread to humans by Anopheles species mosquitoes. The plasmodial parasite reproduces asexually in red blood cells significantly destroying many of them. Release of mature Plasmodium merozoites results in further infection and produces bouts of shivering fever (paroxysms) and sweating that may be fatal. - Stock Video Clip K006/8349
Normal red blood cell (erythrocyte) and red blood cell infected with the malaria parasite (Plasmodium falciparum, schizont stage), coloured scanning electron micrograph (SEM). The upper right red blood cell there is a large protrusion that is the schizont stage of the malaria parasite that is dividing and growing in the red blood cell. Malaria is caused by Plasmodium spp., protozoa. It is spread to humans by Anopheles species mosquitoes. The plasmodial parasite reproduces asexually in red blood cells significantly destroying many of them. Release of mature Plasmodium merozoites results in further infection and produces bouts of shivering fever (paroxysms) and sweating that may be fatal. Magnification: x2,000 when shortest axis printed at 25 millimetres. - Stock Image C032/0956
BioAssay record AID 724374 submitted by ChEMBL: Induction of morphological changes in human erythrocytes at => 60 uM after 1 hr by cold field emission scanning electron microscopic analysis.
TY - JOUR. T1 - Erythrocyte concentrations of the lithium ion. T2 - Clinical correlates and mechanisms of accumulation. AU - Frazer, A.. AU - Mendels, D.. AU - Brunswick, PY - 1978/12/1. Y1 - 1978/12/1. N2 - In spite of the continued uncertainty about the clinical significance of differences in the Lithium Ratio, the authors and others have been studying factors which determine the distribution of Li+ across the RBC membrane in an effort to understand the considerable intersubject variation which has been observed by all investigators. In brief, it appears that the major reason for interindividual variation in the magnitude of the Lithium Ratio is the Li-Na counterflow system.. AB - In spite of the continued uncertainty about the clinical significance of differences in the Lithium Ratio, the authors and others have been studying factors which determine the distribution of Li+ across the RBC membrane in an effort to understand the considerable intersubject variation which has been observed by all ...
Almost all vertebrates, including all mammals and humans, have red blood cells. Red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish (family Channichthyidae); they live in very oxygen-rich cold water and transport oxygen freely dissolved in their blood.[9] While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome.[10]. Vertebrate red blood cells consist mainly of hemoglobin, a complex metalloprotein containing heme groups whose iron atoms temporarily bind to oxygen molecules (O2) in the lungs or gills and release them throughout the body. Oxygen can easily diffuse through the red blood cells cell membrane. Hemoglobin in the red blood cells also carries some of the waste product carbon dioxide back from the tissues; most waste carbon dioxide, however, is transported back to the pulmonary capillaries of the lungs as bicarbonate (HCO3−) dissolved in the blood ...
Almost all vertebrates, including all mammals and humans, have red blood cells. Red blood cells are cells present in blood in order to transport oxygen. The only known vertebrates without red blood cells are the crocodile icefish (family Channichthyidae); they live in very oxygen-rich cold water and transport oxygen freely dissolved in their blood.[8] While they no longer use hemoglobin, remnants of hemoglobin genes can be found in their genome.[9]. Vertebrate red blood cells consist mainly of hemoglobin, a complex metalloprotein containing heme groups whose iron atoms temporarily bind to oxygen molecules (O2) in the lungs or gills and release them throughout the body. Oxygen can easily diffuse through the red blood cells cell membrane. Hemoglobin in the red blood cells also carries some of the waste product carbon dioxide back from the tissues; most waste carbon dioxide, however, is transported back to the pulmonary capillaries of the lungs as bicarbonate (HCO3−) dissolved in the blood ...
Balduzzi M, De Berardis B, Diociaiuti M, Paoletti L. Alterations in erythrocyte morphology induced by physico-chemical characterised particulate matters exhibiting a different hemolytic potential. In: Dini L, Catalano M, ed. 5. Multinational Congress on Electron Microscopy. Proceedings ; September 20-25, 2001; Lecce. 2001. p.37 ...
1. We have purified membrane-associated Ins(1,4,5)P3/Ins(1,3,4,5)P4 5-phosphatases from bovine testis and human erythrocytes by chromatography on several media, including a novel 2,3-bisphosphoglycerate affinity column. 2. The enzymes have apparent molecular masses of 42 kDa (testis) and 70 kDa (erythrocyte), as determined by SDS/PAGE, and affinities for Ins(1,4,5)P3 of 14 microM and 22 microM respectively. 3. The two enzymes hydrolyse both Ins(1,4,5)P3 and Ins(1,3,4,5)P4 and are therefore type I Ins(1,4,5)P3 5-phosphatases [nomenclature of Hansen, Johanson, Williamson and Williamson (1987) J. Biol. Chem. 262, 17319-17326]. 4. On chromatofocusing, the partially purified testicular enzyme migrates as two peaks of activity, with pI values of about 5.8 and 5.5. The erythrocyte enzyme exhibits only the latter peak. 5. The testis 5-phosphatase is labile at 37 degrees C, but its activity can be maintained in the presence of 50 mM phorbol dibutyrate (PdBu). After PdBu treatment, a third form of the ...
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strain FCB-2. It is well known that steroids can alter the membrane function of erythrocytes. Thus, we assessed alterations in the membranes of uninfected red blood cells, the parasite invasiveness and the solute-induced lysis of parasitised red blood cells (pRBCs). induced by SNs. We found that most merozoites were unable to invade SN-treated erythrocytes. However, transmission electron microscopy revealed no effect on the morphology of uninfected erythrocytes treated with either SN2 or diosgenone and neither SN induced haemolysis of uninfected erythrocytes. SN2 and SN4 inhibited isosmotic sorbitol and alanine-induced haemolysis of pRBCs. In contrast, diosgenone and SN1 did not inhibit solute-induced haemolysis. The inhibition of solute-induced lysis of parasitised erythrocytes by SN2 and SN4 suggest an action of these SNs on new permeability pathways of pRBCs ...
Growth of the intraerythrocytic malaria parasite is accompanied by an intense period of membrane biogenesis including production of a vacuolar system that surrounds and supports the parasites expansion in the host cell (Vial et al., 1990). The processes of membrane engineering that underlie this biogenesis begin with parasite invasion of the erythrocyte and continue with development of the surrounding PVM, TVN extensions into the host cell cytoplasm, MC and small vesicles that may move between some of these structures and the host membrane (Aikawa, 1988; Taraschi et al., 2003; Bhattacharjee et al., 2008; Hanssen et al., 2008; Kilian et al., 2013).. The human erythrocyte, although a naturally non-endocytic cell, is induced by the malaria merozoite to invaginate for incorporation of the young parasite into the sealed PVM (Miller et al., 1979). A number of studies have found that the newly formed PVM includes host membrane lipids that flow past the erythrocyte-merozoite moving junction and leave ...
Yokota, S; Beisel, K W.; and David, C S., Murine erythrocyte antigen h-2.7(g): Expression depends on level of complement component c4. (1980). Subject Strain Bibliography 1980. 3571 ...
Main parameters of lipid complex were studied in erythrocytes of whole blood and of the blood containing anticoagulant. Initial steps of blood coagulation involved activation of erythrocyte endogenous phospholipase A, which led to destabilization of erythrocyte lipid structures as a result of an increase in concentration of free fatty acids, accumulation of lysophospholipids as well as of alterations in microviscosity of erythrocyte membranes ...
Antibodies for proteins involved in erythrocyte differentiation pathways, according to their Panther/Gene Ontology Classification
rbc, red blood cells, erythrocytes, red blood cells anatomy, red blood cells physiology, erythrocyes, erythrocytes anatomy, erythrocytes physiology, anatomy of red blood cells, anatomy red blood cells, physiology of red blood cells, physiology red blood cells,
In the current study, the researchers wove observations from previous investigations into a testable hypothesis. They took into account deposition of iron-presumably from iron-rich red blood cells (erythrocytes)-in kidneys of individuals with renal disorders. They also considered the kidneys role in clearing erythrocytes from circulation as the cells become old or damaged.. During a process called erythrophagocytosis, aging erythrocytes are enveloped and broken down by other cells. Erythrophagocytosis occurs primarily in cells of the spleen and liver, but proximal tubular epithelial cells in the kidney also have this capability. The signal that an erythrocyte needs to be removed from circulation comes from a compound called phosphatidylserine (PS). In a normal, healthy erythrocyte, PS is an internal cellular component, with no direct contact with the cells outer environment. Aged and damaged red blood cells begin to shift PS to the outer surface. Members of this research team previously found ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Your body may increase red blood cell production to compensate for any condition that results in low oxygen levels, including: Information and translations of red cell in the most comprehensive dictionary definitions resource on the web. To read the comment, hover over the cell containing the red triangle. CORONAVIRUS: DELAYS FOR ROUTINE SURGERIES, VISITOR RESTRICTIONS + COVID-19 TESTING. Doctors measure your red blood cell count to help diagnose medical conditions and learn more about your health. Red blood cells are one of the major components of blood, along with white blood cells and platelets. As part of the complete blood count, red blood cell count is used during general check-up as well as to check specific health problems like anemia and internal bleeding among others. A red blood cell count is a blood test that your doctor uses to find out how many red blood cells (RBCs) you have. Red Teams or Red Cells are United States Government terms for the National Security Co-ordination Team ...
Red blood cells are the most abundant cells in our bodies and supply our tissues with oxygen. In order to transport oxygen these cells are packed with hemoglobin molecules. Defects to the genes encoding these molecules can result in premature breakdown of red blood cells, which results in too few red bloods also called anemia. People with severe forms of anemia can even become dependent on recurring blood transfusions. This thesis aims to find alternative treatments for anemias by detailed investigation of the process through which red blood cells are formed and the regulation of the different hemoglobin genes in this process. It describes the optimization of a cell culture medium that helps to grow large amounts of red cells for transfusion purposes and it describes a possible role for environmental signals in the control of hemoglobin gene expression. Additionally, outlines how specific variants of KLF1, a regulatory protein, alter hemoglobin expression in both human and mice. Combined these ...
H2O2 degradation in erythrocytes has been studied for several decades in connection with the high oxygen turnover of these cells and the toxic properties of ROS derived from H2O2 metabolism.11 36 37 Interest in this area was renewed by articles describing a role for H2O2 in signal transduction.5 38 In the present study, we have determined both catalase and GPO activities in hemolysate at physiological H2O2 concentrations by using a novel H2O2 assay.23 25 Because erythrocyte catalase and GPO are apparently not compartmentalized,34 the studies performed on hemolysates may reflect a situation similar to that in the erythrocyte. The luminol/hypochlorite method may be used to determine H2O2 degradation by GPO in the 10−7 mol/L H2O2 range and at GSH concentrations normally found in erythrocytes.. The assumption that the glutathione-GPO system has greater affinity for its substrate led both Keilin and Hartree39 and Cohen and Hochstein10 to suggest that at H2O2 concentrations below 10−7 mol/L, ...
Red blood cells are stored in blood collection centres for blood transfusion; however, some of red blood cells are discarded due to the poor quality after storage for a period of time because the poor quality of the red blood cells will cause health problems in individuals after transfusion. In this project, we are going to test new compounds derived from natural anti-freezing proteins by a Canada-based biotech company Sirona for better storage of red blood cells. Hopefully, we will find that these new compounds can improve the quality of the red blood cells after storage.. ...
The average size of your red blood cells. This test is known as mean corpuscular volume (MCV). MCV goes up when your red blood cells are bigger than normal. This happens if you have anemia caused by low vitamin B12 or folate levels. If your red blood cells are smaller, this can mean other types of anemia, such as iron deficiency anemia. ...
1. The distribution of proteolytic activity in membranes from human erythrocytes and from rabbit reticulocytes and erythrocytes was investigated, after removal of leucocytes and platelets from the cell suspensions. 2. All membrane preparations displayed proteolytic activity in the acidic pH region only. Membranes from human and rabbit mature erythrocytes showed latent activity, which could be increased when extracted with a number of detergents. 3. Three active fractions were resolved either by gel chromatography of solubilized membrane extracts or by standard polyacrylamide-gel electrophoresis. The three proteinase activities (designated proteinases I, II and III) were purified from solubilized extracts of human erythrocyte membranes. 4. The relevant mol.wts. were around 80000, 40000 and 30000, respectively, and each of the three proteinases appeared to be composed of a single polypeptide chain. 5. Distinctive pH optima (in the range pH2.8-3.9) and different saturation profiles with globin as ...
Erythrocyte fragility refers to the propensity of erythrocytes (red blood cells, RBC) to hemolyse (rupture) under stress. It can be thought of as the degree or proportion of hemolysis that occurs when a sample of red blood cells are subjected to stress (typically physical stress, and most commonly osmotic and/or mechanical stress). Depending on the application as well as the kind of fragility involved, the amount of stress applied and/or the significance of the resultant hemolysis may vary. When multiple levels of stress are applied to a given population/sample of cells, a fragility profile can be obtained by measuring the relative or absolute extent of hemolysis existing at each such level, in addition to finding one or more single-number indexes (either measured directly or interpolated) associated with particular respective levels of hemolysis and/or corresponding stress. Fragility testing can be useful to assess cells ability (or lack thereof) to withstand sustained or repeated stress. ...
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A cell that contains hemoglobin and can carry oxygen to the body. Also called a red blood cell (RBC). The reddish color is due to the hemoglobin. Erythrocytes are biconcave in shape, which increases the cells surface area and facilitates the diffusion of oxygen and carbon dioxide. This shape is maintained by a cytoskeleton composed of several proteins. Erythrocytes are very flexible and change shape when flowing through capillaries. Immature erythrocytes, called reticulocytes, normally account for 1-2 percent of red cells in the blood. ...
Red blood cells (RBCs), also called erythrocytes, are the most common type of blood cell and the vertebrates principal means of delivering oxygen (O2) to the body tissues-via blood flow through the circulatory system. RBCs take up oxygen in the lungs, or gills of fish, and release it into tissues while squeezing through the bodys capillaries. The cytoplasm of erythrocytes is rich in hemoglobin, an iron-containing biomolecule that can bind oxygen and is responsible for the red color of the cells. The cell membrane is composed of proteins and lipids, and this structure provides properties essential for physiological cell function such as deformability and stability while traversing the circulatory system and specifically the capillary network. In humans, mature red blood cells are flexible and oval biconcave disks. They lack a cell nucleus and most organelles, in order to accommodate maximum space for hemoglobin; they can be viewed as sacks of hemoglobin, with a plasma membrane as the sack. ...
Erythrocytes in mammals are anucleate when mature, meaning that they lack a cell nucleus and as a result, have no DNA. Red blood cells have nuclei during early phases of development, but extrude them as they mature in order to provide more space for hemoglobin. In comparison, the erythrocytes of nearly all other vertebrates have nuclei; the only known exception being salamanders of the Batrachoseps genus.[4] Mammalian erythrocytes also lose their other organelles such as their mitochondria. As a result, red blood cells produce ATP through glycolysis only and therefore use none of the oxygen they carry. Furthermore, red cells do not have an insulin receptor and thus glucose uptake is not regulated by insulin. Because of the lack of nucleus and organelles, the red blood cells cannot synthesize any RNA so they cannot divide or repair themselves. Mammalian erythrocytes are biconcave disks: flattened and depressed in the center, with a dumbbell-shaped cross section. This shape (as well as the loss of ...
TY - JOUR. T1 - Chondroitin sulfate proteoglycan but not hyaluronic acid is the receptor for the adherence of Plasmodium falciparum-infected erythrocytes in human placenta, and infected red blood cell adherence up-regulates the receptor expression. AU - Muthusamy, Arivalagan. AU - Achur, Rajeshwara N.. AU - Valiyaveettil, Manojkumar. AU - Botti, John J.. AU - Taylor, Diane W.. AU - Leke, Rose F.. AU - Gowda, D. Channe. PY - 2007/6. Y1 - 2007/6. N2 - A low-sulfated chondroitin sulfate proteoglycan (CSPG) has been shown to be the receptor for the adherence of Plasmodium falciparum-infected red blood cells (IRBCs) in human placenta. Recently, hyaluronic acid (HA) has been suggested as an additional receptor even though IRBC binding to HA and the presence of HA at locations where IRBCs adhere in the placenta have not been established. In this study, we investigated whether HA is also a receptor for IRBC binding. IRBCs from infected placentas as well as those from different laboratory strains could ...
The ability of Plasmodium falciparum-infected red blood cells (RBC) to form spontaneous erythrocyte rosettes was studied in 130 fresh isolates from Gambian children with cerebral or uncomplicated malaria from August to November 1990. All isolates (24 of 24) from patients with cerebral malaria formed rosettes, but only 61 of 106 isolates from children with uncomplicated malaria formed rosettes. The mean rate of rosette formation in isolates from children with cerebral malaria (28.3%) was significantly greater than that in isolates from children with uncomplicated malaria (8.5%). Giant rosettes were more frequently formed in isolates from patients with cerebral malaria than in those from patients with uncomplicated malaria. Sera of children with cerebral disease generally lacked anti-rosette activity, while many sera from children with uncomplicated malaria showed strong anti- rosette activity when tested against the patients ow parasites. Some sera that were devoid of autologous rosette-disrupting
TY - JOUR. T1 - Large scale isolation of human erythrocyte membranes by high volume molecular filtration. AU - Rosenberry, Terrone L.. AU - Chen, Jeffrey F.. AU - Lee, Mary M.L.. AU - Moulton, Thomas A.. AU - Onigman, Philip. PY - 1981/1. Y1 - 1981/1. N2 - A molecular filtration procedure for preparing large quantities of human erythrocyte ghost membranes is presented. Hemolysate ghost membranes are rapidly cycled in the retantate channel of the filtration apparatus, while hemoglobin is removed s it pass through Pellicon filters into the filtrate. Several-liter quantities of washed packed erythrocytes can be processed in a few hours with this system and the filtration procedure does not appear to alter erythrocyte or ghost membranes. Intact erythrocytes in isotonic solution can be circulated through the retentate channel for 16 h with only 3% hemolysis and with preservation of their orginal morphology in scanning electron microscopy. Ghost membranes isolated by the procedure are virtually ...
Plasmodium falciparum infecting hemoglobin (Hb)H and/or Hb Constant Spring erythrocytes has higher resistance to artemisinin in vitro than when infecting normal erythrocytes. This is due to low drug accumulation of infected erythrocytes resulting from competition with uninfected variant erythrocytes, which have a higher accumulation capacity than genetically normal cells. Drug accumulation of the parasite was shown to be saturable and dependent on metabolic energy. The 50% inhibitory concentrations (IC50s) for the parasite in HbH/Hb Constant Spring erythrocytes were decreased when normal erythrocytes were added to the infected cells, and correspondingly, the IC50s in normal erythrocytes were increased when HbH/Hb Constant Spring erythrocytes were added to the infected cells. The changes of IC50 corresponded to the variation in drug accumulation of mixtures of normal and variant erythrocytes of different compositions. The IC50s for the parasite in variant erythrocytes were also greatly ...
TY - JOUR. T1 - Scanning tunneling microscopy of human erythrocyte membranes. AU - Gaczynska, M.. AU - Chwialkowski, M.. AU - Olejniczak, W.. AU - Wojczuk, S.. AU - Bartosz, G.. PY - 1991/12/16. Y1 - 1991/12/16. N2 - Images of surfaces of human erythrocyte ghosts, lecithin liposomes, spectrin, erythrocyte membrane skeleton, concanavalin A and concanavalin A - decorated erythrocyte ghosts were obtained by scanning tunneling microscopy. The dimensions and surface topography of some membrane structures are described and discussed.. AB - Images of surfaces of human erythrocyte ghosts, lecithin liposomes, spectrin, erythrocyte membrane skeleton, concanavalin A and concanavalin A - decorated erythrocyte ghosts were obtained by scanning tunneling microscopy. The dimensions and surface topography of some membrane structures are described and discussed.. UR - http://www.scopus.com/inward/record.url?scp=0026344388&partnerID=8YFLogxK. UR - ...
TY - JOUR. T1 - Erythrocyte morphology in women with severe preeclampsia and eclampsia. Preliminary observations with scanning electron microscopy. AU - Cunningham, F. Gary. AU - Lowe, Thomas. AU - Guss, Steve. AU - Mason, Ruble. PY - 1985/10/15. Y1 - 1985/10/15. N2 - Scanning electron microscopy was used to study the morphologic characteristics of erythrocytes in women with preeclampsia and eclampsia. In nine nulliparous women with eclampsia, the proportion of abnormal red cells (schistocytes, echinocytes, and spherocytes) was significantly greater than in 12 normally pregnant control women (p , 0.001). Likewise, the proportion of these abnormal erythrocyte forms was significantly greater in 12 nulliparous women with preeclampsia than in 25 normally pregnant control women (p = 0.009). Six women with mild pregnancy-induced hypertension without proteinuria were studied before and after magnesium sulfate therapy had been given, and no differences in the proportion of abnormal erythrocyte forms ...
TY - JOUR. T1 - Circadian variations in plasma and erythrocyte concentrations of glutamate, glutamine, and alanine in men on a diet without and with added monosodium glutamate. AU - Tsai, Po Jung. AU - Huang, Po Chao. PY - 1999. Y1 - 1999. N2 - Variations in plasma and erythrocyte concentrations of glutamate, glutamine, and alanine during the day were studied in 10 healthy men fed ordinary Taiwanese meals, first without and, 1 week later, with monosodium glutamate (MSG) added. MSG at a level of 15, 40, and 45 mg/kg (total, 100 mg/kg/d) was added, respectively, to the breakfast, lunch, and dinner meals. Heparinized blood samples were collected over 24 hours with 1- to 3-hour intervals. In both trials, plasma glutamate concentrations increased significantly after lunch and dinner. Although the circadian variations of plasma glutamate were small (between 32 and 53 μmol/L), the levels nevertheless varied significantly as a function of the time of day in both trials. Considering that the dietary ...
What is Sickle Cell Disease?. Just as we inherit color of our eye and our hair from our parents, some diseases can also be inherited. Sickle cell disease is an inherited disorder or the hemoglobin in the red blood cells. Characteristics of our hemoglobin are also inherited, or passed on through the genes, from our parents.. Normal red blood cells are disc-shaped and flexible. The hemoglobin of individuals with normal red blood cells is called Hemoglobin (Hb) a. individuals with sickle cell anemia have inherited genes, that cause their red blood cell to take on the shape of a crescent or sickle when they lose oxygen to the body tissues.. Their hemoglobin is called S.. Sickle-shaped cells cannot pass easily through the small blood vessels and may result in blockage in the blood vessels. This blockage often results in painful crises and may lead to many other serious complications such as bone damage and leg ulcers. Once the cells are sickled they become more fragile and tend to be more easily ...
In order to gain insight into the molecular mechanism of the antioxidant properties of Solanum crispum, aqueous extracts of its leaves were assayed on human erythrocytes and molecular models of its membrane. Phenolics and alkaloids were detected by HPLC-MS. Scanning electron and defocusing microscopy showed that S. crispum changed erythrocytes from the normal shape to echinocytes. These results imply that molecules present in the aqueous extracts were located in the outer monolayer of the erythrocyte membrane. Dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE) were chosen as representative of phospholipid classes located in the outer and inner monolayers of the erythrocyte membrane, respectively. X-ray diffraction showed that S. crispum preferentially interacted with DMPC bilayers. Experiments regarding its antioxidant properties showed that S. crispum neutralized the oxidative capacity of HClO on DMPE bilayers; defocusing microscopy and hemolysis assays ...
Chan JA, Boyle MJ, Moore KA, Reiling L, Lin Z, Hasang W, Avril M, Manning L, Mueller I, Laman M, Davis T, Smith JD, Rogerson SJ, Simpson JA, Fowkes FJI, Beeson JG. Antibody Targets on the Surface of Plasmodium falciparum-Infected Erythrocytes That Are Associated With Immunity to Severe Malaria in Young Children. The Journal of infectious diseases 219 (5) : 819 - 828(2019) PubMed ...
To understand the molecular mechanisms that lead to sequestration of red blood cells infected with mature stages of Plasmodium falciparum and to examine the relevance of earlier studies on adherence properties of laboratory-derived P falciparum parasites to the natural parasite population, we analyzed Gambian and Tanzanian isolates for in vitro cytoadherence and antibody-mediated microagglutination. Eighteen cryopreserved isolates of ring-stage parasites were cultured for 20 to 30 hours in vitro, in the patients original erythrocytes, to the trophozoite and schizont stage. All parasites were positive in the microagglutination assay with at least one of four African hyperimmune sera. In a rosetting assay, only 2 of the 18 isolates were strongly positive (35% and 41% of parasitized erythrocytes with more than two uninfected cells bound). Thirteen isolates showed either intermediate (5% to 18%) or low (less than 5%) rosetting while three isolates did not form rosettes. Infected cell-binding of the ...
BACKGROUND: The standard preservation solution used during organ procurement and preservation of most organs is the University of Wisconsin (UW) solution. Despite its superiority over other cold storage solutions, the inclusion of hydroxyethyl starch (HES) as one of the components of the UW solution has been both advocated and denied. This study determined whether HES had any effect on red blood cell (RBC) aggregability and correlated aggregation parameters with HES molecular weight. METHODS: Human RBC aggregability and deformability were investigated in vitro, at 4 degrees C, with a laser-assisted optical rotation cell analyzer. The study of RBC aggregation in a binary HES-HES system gave an indication about the nature of HES-RBCs interactions. Bright field microscopy and atomic force microscopy were used to morphologically characterize the aggregates size and form. RESULTS: High molecular weight HES and UW solution had a potent hyperaggregating effect; low molecular weight HES had a hypoaggregating
Rosetting, i.e. the capacity of red blood cells (iRBCs) infected with mature parasite stages to bind two or more uninfected red blood cells (RBCs) is a virulence factor of Plasmodium falciparum. This protocol describes an in vitro assay to monitor rosette formation by P. falciparum-infected red blood cells, including procedures for rosette enrichment, maintenance of rosetting phenotype and assays for rosetting with RBC labeled using lipophilic fluorescent probes.
Erythrocyte invasion by Plasmodium falciparum is central to the pathogenesis of malaria. Invasion requires a series of extracellular recognition events between erythrocyte receptors and ligands on the merozoite, the invasive form of the parasite. None of the few known receptor-ligand interactions involved are required in all parasite strains, indicating that the parasite is able to access multiple redundant invasion pathways. Here, we show that we have identified a receptor-ligand pair that is essential for erythrocyte invasion in all tested P. falciparum strains. By systematically screening a library of erythrocyte proteins, we have found that the Ok blood group antigen, basigin, is a receptor for PfRh5, a parasite ligand that is essential for blood stage growth. Erythrocyte invasion was potently inhibited by soluble basigin or by basigin knockdown, and invasion could be completely blocked using low concentrations of anti-basigin antibodies; importantly, these effects were observed across all ...
Superoxide dismutase (SOD) is an important antioxidant that protects many types of cells from the free radical damage. One of the possible ways for the use of SOD is its incorporation in liposomes. The aim of this study was to investigate the effect of cationic phospholipids on the entrapment of human erythrocyte superoxide dismutase (Cu/Zn SOD) in liposomes. Also, in the present study, we examined the effect of this formulation on the permeability of these liposomes for SOD at two different temperatures (4 °C and 37 °C). Cu/Zn SOD was purified from human erythrocytes. Several methods, including, precipitation by acetone, chloroform, centrifugation and also ion exchange chromatography on DEAE-32 were applied. In this study, encapsulated SOD in liposomes was prepared using the film hydration method. The results obtained from the prepared human erythrocyte SOD showed that at the end of the last stage, the purification was 21 times the result of the first stage, with a specific activity of 3000 U
The passive K influx in low K(LK) red blood cells of sheep saturates with increasing external K concentration, indicating that this mode of transport is mediated by membrane-associated sites. The passive K influx, iMLK, is inhibited by external Na. Isoimmune anti-L serum, known to stimulate active K transport in LK sheep red cells, inhibits iMLK about twofold. iMLK is affected by changes in intracellular K concentration, [K]i, in a complex fashion: increasing [K]i from near zero stimulates iMLK, while further increases in [K]i, above 3 mmol/liter cells, inhibit iMLK. The passive K influx is not mediated by K-K exchange diffusion. The effects of anti-L antibody and [K]i on passive cation transport are specific for K: neither factor affects passive Na transport. The common characteristics of passive and active K influx suggest that iMLK is mediated by inactive Na-K pump sites, and that the inability to translocate Na characterizes the inactive pumps. Anti-L antibody stimulates the K pump in ...
TY - JOUR. T1 - Methylmercury binds to a low molecular weight substance in rabbit and human erythrocytes. AU - Naganuma, Akira. AU - Imura, Nobumasa. PY - 1979/3/15. Y1 - 1979/3/15. N2 - Behavior of methylmercury in animal blood was investigated by gel filtration of stroma-free hemolysates from rat, rabbit, and human erythrocytes, treated with methylmercury. In the rabbit and human erythrocytes, methylmercury was bound to a low molecular weight substance rather than hemoglobin, while almost all of methylmercury in the rat erythrocyte was bound to the hemoglobin fraction. The methylmercury-bound substance of low molecular weight in rabbit erythrocytes showed a similar behavior pattern to that of glutathione (GSH) bound with methylmercury on gel filtration with Sephadex G-15 and thin-layer chromatography.. AB - Behavior of methylmercury in animal blood was investigated by gel filtration of stroma-free hemolysates from rat, rabbit, and human erythrocytes, treated with methylmercury. In the rabbit ...
1 The characteristics of the binding of 12‐alpha‐[3H]‐digoxin to the membranes of intact human erythrocytes are described. 2 Only one class of binding site can be demonstrated. Binding is time‐ and temperature‐ dependent, saturable and slowly reversible; it is inhibited by other cardiac glycosides and by potassium. 3 Pre‐incubation with unlabelled digoxin reduces the subsequent binding of 12‐alpha‐[3H]‐digoxin in stoichiometric fashion. 4 The possible application of the measurement of the binding of 12‐alpha‐[3H]‐digoxin to the study of biochemical pharmacological events occurring during digoxin therapy is discussed. 1979 The British Pharmacological Society
The concentration of folate in erythrocytes was determined using a two-phase ligand-binding radioassay procedure described previously for measuring serum folate. The mean (± SD) folate concentration in erythrocytes of 20 normal subjects was 210 ± 57 ng/ml. In 12 patients clinically folate deficient who had normal serum B12 concentration, the mean (± SD) erythrocyte folate was 71 ± 39 ng/ml. Incubation of the lysed erythrocytes for 2 hr prior to boiling increased the radioassayable folate. The radioassayable folate decreased rapidly if the whole blood was stored at 4°C without ascorbate. Extracts of blood prepared with ascorbate could be stored at -20°C for several days. The radioassayable concentration of erythrocyte folate was similar to the values obtained using Lactobacillus casei when the concentration was 200 ng/ ml or less. With values higher by L. casei, the radioassayable folate was significantly lower even though the normal and folate-deficient groups were distinctly separated. ...
Review question We wanted to determine if long-term blood transfusions given to people with sickle cell disease who are at a higher risk of stroke (primary prevention) or have had a previous stroke (secondary prevention) decreases their risk of a subsequent stroke without causing severe side effects. We compared long-term blood transfusions to standard treatment or other ways of preventing a stroke. This is an update of a previously published Cochrane Review.. Interventions for silent stroke are addressed in a separate Cochrane Review.. Background Sickle cell disease is a serious inherited blood disorder where the red blood cells, which carry oxygen around the body, develop abnormally.. Normal red blood cells are flexible and disc-shaped, but in sickle cell disease they can become rigid, crescent shaped and also stickier. This can lead to blockage of blood vessels, resulting in tissue and organ damage and episodes of severe pain. The abnormal blood cells are more fragile and break apart, which ...
The Doctors Medical Library. Health and Healing Information. Physician, Health care help, An erythrocyte is a cell that contains hemoglobin and can carry oxygen to the body and is also called a red blood cell (RBC). The reddish color is due to the hemoglobin. Erythrocytes are biconcave in shape, which increases the cells surface area and facilitates the diffusion of oxygen and carbon dioxide. This shape is maintained by a cytoskeleton composed of several proteins. Erythrocytes are very flexible and change shape when flowing through capillaries becoming parachute shaped in order to fit through capillaries which are small in diameter than erythrocytes. Immature erythrocytes, called reticulocytes, normally account for 1-2 percent of red cells in the blood.
INTRODUCTION: Hypertension is associated with microcirculatory disturbance, and erythrocyte deformability is a major determinant of the microcirculation. However, impairment of erythrocyte deformability in hypertensive patients in relation to antihypertensive treatment is unclear. The present study aimed to investigate this impairment in hypertensive patients under treatment using a highly sensitive and quantitative nickel mesh filtration technique. METHODS: Deformability was evaluated by filterability, defined as the flow rate of a hematocrit-adjusted erythrocyte suspension relative to that of saline under a specific filtration pressure in a pressure-flow curve obtained by continuous filtration. Baseline characteristics of hypertensive patients (n = 101) and age-matched normotensive subjects (n = 14) were obtained from medical records, and diabetic patients were excluded. RESULTS: Erythrocyte deformability in the hypertensive group was significantly (p = 0.010) lower (87.8 +/- 2.2 %) than that ...
Peripheral blood smears were available for staging from 14 of 17 cases. Ring forms comprised the majority of parasite types observed in all cases (Fig. 1), and mature-stage parasites were observed in only 7 of 14 cases examined. Overall, 96.5% ± 1.9% (range, 79.4 to 100%) of all IEs were ring forms (Fig. 1), and no schizonts were seen. The mean parasitemia of pigmented trophozoites in placental washings was over 200 times higher than that of peripheral blood (11.2% versus 0.048%).. These findings indicate that IEs selectively accumulate in the blood spaces of the placenta. This is predominantly a feature of pigmented trophozoites, which express PfEMP1 on their surface (11) and may adhere to CSA and HA or bind immunoglobulins (4, 8, 14, 18). The intraerythrocytic parasite life cycle lasts approximately 48 h, with 24 h in the ring stage, 12 h as pigmented trophozoites, and 12 h as schizonts (20). Therefore, in the absence of selective processes, random sampling of parasites should yield ...
Have you ever seen a sickle? Its a farm tool with a curved, sharp edge for cutting wheat. Sickle cell anemia (say: uh-nee-mee-uh) is a disease of the blood. It gets its name because a persons red blood cells are shaped like sickles, or crescent moons, instead of their usual round, disc shape.. Round is the healthiest shape for red blood cells (or RBCs) because they can move easily through the body. RBCs carry oxygen around your body, and every part of your body needs oxygen to work properly.. Red blood cells are made inside the bones in the soft, spongy area called the bone marrow (say: mair-oh). Every time you take a breath, you breathe in oxygen and your RBCs carry oxygen to every cell in your body. When a persons body doesnt have enough red blood cells, its called anemia. When the cause is the sickle shape of the RBCs, its called sickle cell anemia.. When RBCs are shaped like sickles or crescent moons, they can get stuck, especially inside smaller blood vessels. This keeps blood from ...
These studies provide the first in vivo evidence that CR1 expression on erythrocytes has an actual, and not just a theoretical (24), effect on the clearance of pneumococci from the blood. We have demonstrated that human CR1 expression on mouse erythrocytes enhances the immune adherence of pneumococci to erythrocytes, facilitates the transfer of pneumococci to phagocytes, and improves the clearance of pneumococci from the blood of infected mice.. Prior studies demonstrated the activity of human soluble CR1 (sCR1) in mouse models of disease and showed that sCR1 and its fragments are active against the mouse alternative pathway of complement activation, which suggests at least some interaction between sCR1 and mouse C3b (25). However, the behavior of sCR1 may differ from that of membrane-bound CR1. Our data establish both in vitro and in vivo that mouse complement can interact with human CR1 expressed on murine erythrocytes in the transgenic model. This was demonstrated by comparisons of the ...
TY - JOUR. T1 - Revealing mechanisms underlying variation in malaria virulence. T2 - Effective propagation and host control of uninfected red blood cell supply. AU - Metcalf, C. J.E.. AU - Long, G. H.. AU - Mideo, N.. AU - Forester, J. D.. AU - Bjørnstad, O. N.. AU - Graham, A. L.. PY - 2012/11/7. Y1 - 2012/11/7. N2 - Malaria parasite clones with the highest transmission rates to mosquitoes also tend to induce the most severe fitness consequences (or virulence) in mammals. This is in accord with expectations from the virulence-transmission trade-off hypothesis. However, the mechanisms underlying how different clones cause virulence are not well understood. Here, using data from eight murine malaria clones, we apply recently developed statistical methods to infer differences in clone characteristics, including induction of differing host-mediated changes in red blood cell (RBC) supply. Our results indicate that the within-host mechanisms underlying similar levels of virulence are variable and ...
The mature erythrocyte is a terminally differentiated, nonendocytic cell in nature. Membrane invagination is uncommon in mature healthy erythrocytes. However, these cells are readily invaded by malaria parasites, which involute the red cell1,2 to generate a host-derived parasitophorous vacuolar membrane (PVM). This process is central to the establishment of the blood-stage infection that is responsible for all symptoms and pathologies of this major human disease.3. Recently, we and others have shown that erythrocytes contain detergent-resistant membranes (DRMs).4⇓⇓⇓⇓⇓-10 These highly buoyant, lipid-rich complexes have also been isolated from various other cell types and appear to be enriched for proteins and lipids present in lipid rafts of cellular membranes. The leading definition of membrane rafts suggests that they may consist of small dynamic domains in the plasma membrane stabilized by cholesterol11 and in response to various stimuli coalesce into a larger, less mobile zone, as ...
Acute and chronic Plasmodium falciparum infections alter the immune competence of the host possibly through changes in dendritic cell (DC) functionality. DCs are the most potent activators of T cells, and migration is integral to their function. Mature DCs express lymphoid chemokine receptors (CCRs), expression of which enables them to migrate to the lymph nodes, where they encounter naïve T cells. The present study aimed to investigate the impact of the synthetic analog to malaria parasite pigment hemozoin, i.e., β-hematin, or infected erythrocytes (iRBCs) on the activation status of human monocyte-derived DCs and on their expression of CCRs. Human monocyte-derived DCs partially matured upon incubation with β-hematin as indicated by an increased expression of CD80 and CD83. Both β-hematin and iRBCs provoked the release of proinflammatory and anti-inflammatory cytokines, such as interleukin-6 (IL-6), IL-10, and tumor necrosis factor alpha, but not IL-12, and induced upregulation of the ...
315. A+chur, R. N., Valiyaveettil, M., Alkhalil, A., Ockenhouse, C. F., Gowda, C. D. Chondroitin sulfate proteoglycan-mediated adherence of plasmodium falciparum-infected erythrocytes to human placenta. Glycobiology 2000; 10:166. 316. Achur, R. N., Valiyaveettil, M., Alkhalil, A., Ockenhouse, C. F., Gowda, C. D. Identification of chondroitin sulfate proteoglycans that mediate the adherence of Plasmodium falciparum-infected erythrocytes to human placenta and structural requirements for adherence. Am J Trop Med Hyg 2000; 62(3 Suppl):207. 317. Alger, J., Salgado, L. J., Fernandez, E., Andrade, H., Pang, L., Saravia, N. G., Krogstad, D. J. Recurrent malaria infection in an endemic area on the northern coast of Honduras. Am J Trop Med Hyg 2000; 62(3 Suppl):401. 318. Alkhalil, A., Achur, R. N., Ockenhouse, C. F., Gowda, D. C. Adherence of malaria parasite-infected erythrocytes to human placenta. FASEB J 2000; 14(8):A1395. 319. Atkins, J. L., Bentley, T. B., Nelson, L. D., Pearce, F. J. Evaluation of ...
TY - JOUR. T1 - Biochemical and morphological properties of bovine erythrocyte membrane glycoproteins. AU - Fletcher, M. A.. AU - Brunschwig, J. P.. AU - Lo, H.. AU - Caldwell, K. E.. AU - Lo, T. M.. PY - 1982. Y1 - 1982. N2 - The major and minor sialoglycoproteins of the bovine erythrocyte have been solubilized and extensively purified. A comparison of composition revealed that the major glycoprotein had 77% carbohydrate and 23% peptide, and the minor one had 27% carbohydrate and 73% peptide. Molar ratios of sugars were related, however, the major glycoprotein had twice as much galactose and sialic acid as did the minor glycoprotein. Molecular weights, estimated from retardation coefficients of mobility in sodium dodecyl sulfate gel electrophoresis, were 55,000 for the major glycoprotein and 34,000 for the minor glycoprotein. The glycoproteins were studied by electron microscopy before and after delipidation and after ultracentrifugation. The major glycoprotein, prior to delipidation, formed ...
Fingerprint Dive into the research topics of Hydrolysis of cis- and trans-epoxyeicosatrienoic acids by rat red blood cells. Together they form a unique fingerprint. ...
Abstract. Drug delivery systems including chemical, physical and biological agents that enhance the bioavailability, improve pharmacokinetics and reduce toxicities of the drugs. Carrier erythrocytes are one of the most promising biological drug delivery systems investigated in recent decades. The bioavailability of statin drugs is low due the effects of P-glycoprotein in the gastro-intestinal tract as well as the first-pass metabolism. Therefore in this work we study the effect of time, temperature as well as concentration on the loading of pravastatin in human erythrocytes to be using them as systemic sustained release delivery system for this drug. After the loading process is performed the carriers erythrocytes were physically and cellulary characterized. Also, the in vitro release of pravastatin from carrier erythrocytes was studied over time interval. Our results revealed that, human erythrocytes have been successfully loaded with pravastatin using endocytosis method either at 25oC or at ...
Research Report on Global Erythrocyte Catalase Sales Market Report 2017. The Report includes market price, demand, trends, size, Share, Growth, Forecast, Analysis & Overview.
In vitro hemolysis can be an important unwanted effect in medical tests and can cause inaccurate results, because the contents of hemolysed red blood cells are included with the serum. The concentration of potassium inside red blood cells is much higher than in the serum and so an elevated potassium is usually found in biochemistry tests of hemolysed blood. If as little as 0.5% of the red blood cells are lysed the serum will have a visually obvious pinkish colour, due to hemoglobin. In vitro hemolysis can occur in a blood sample owing prolonged storage or storage in incorrect conditions (ie too hot, too cold). Hemolysis can also occur at the time of venipuncture, but it is uncommon when the venipuncture is straightforward and the phlebotomist is experienced. Excessive suction can cause the red blood cells to be literally smashed on their way through the hypodermic needle owing to turbulence and physical forces. Such hemolysis is more likely to occur when a patients veins are difficult to find ...
A cyclic depsipeptide antibiotic, valinomycin, was found to produce increased selective permeability of the plasma membranes of HK and LK sheep red blood cells to potassium but not to sodium ions. The compound had relatively little effect on the active extrusion of sodium from HK sheep red blood cells or on the Na + K-stimulated ATPase activity of membranes derived from these cells. It is proposed that the selective cation permeability produced by this compound depends primarily on steric factors, particularly the relationship between the diameter of the ring and the effective diameter of the ion. The significance of these results for the problem of the mechanism of ionic selectivity in natural membranes is discussed.. ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
Immune-mediated hemolytic anemia (IMHA) is a type of illness known as an autoimmune disease. Autoimmune diseases result when the bodys immune system does not recognize itself; cells that normally attack invading viruses and bacteria begin attacking the bodys own cells, causing damage. In dogs and cats with IMHA, the bodys red blood cells come under attack. When red blood cells are severely damaged, they can burst; this is known as hemolysis. Therefore, IMHA is a condition in which red blood cells are attacked by the bodys immune system and destroyed by hemolysis, resulting in anemia (an inadequate quantity of red blood cells). Red blood cells can be destroyed within the blood vessels or in the spleen, liver, or bone marrow (where they are produced).. Read More ...
The elliptical, anucleate erythrocytes of camels have been examined for the presence of marginal bands and their constituent microtubules. Lysis of erythrocytes under microtubule-stabilizing conditions readily revealed marginal bands in at least 3 % of the cells, as observed by phase-contrast and darkfield light microscopy. Microtubules plus a marginal band-encompassing network of material are visible in lysed cell whole mounts with transmission electron microscopy. Marginal band microtubules are also evident in electron micrographs of thin-sectioned camel erythrocytes identifiable as reticuloyctes on the basis of submaximal electron density (reduced haemoglobin iron content) and presence of polysomes. The results suggest that marginal bands may be involved in morphogenesis of camel erythrocytes but are not required for maintenance of their ellipticity after cells are fully differentiated. ...
The erythrocyte component carrying the Duffy blood group antigen Fya has been identified as a 35- to 43-kilodalton protein. The protein is degraded by proteases, chymotrypsin, and Pronase, which destroy its antigenicity on intact erythrocytes. Its unusual property of aggregating on being boiled in 5 percent sodium dodecyl sulfate with 5 percent 2-mercaptoethanol distinguishes it from other erythrocyte membrane proteins described to date. ...
Researchers at Duke University Medical Center may finally have discovered why people with sickle cell disease get milder cases of malaria than individuals who have normal red blood cells.. The paper shows that the dysregulated microRNA (miRNA) composition, of either heterozygous HbAS or homozygous HbSS erythrocytes, contributes to resistance against P. falciparum. . One of the most interesting findings in our study is that the human microRNA found in sickle red cells directly participate in the gene regulation of malaria parasites, said Dr. Jen-Tsan Chi, M.D., Ph.D., senior author and associate professor in the Duke Institute for Genome Sciences and Policy and Department of Molecular Genetics and Microbiology. These microRNAs enriched in the sickle red cells reduce the parasites ability to propagate, so that certain people stay more protected.. During the intraerythrocytic life cycle of P. falciparum, a subset of erythrocyte miRNAs translocate into the parasite. Two miRNAs, miR-451 and ...
1. Erythrocyte choline transport was studied in 10 haemodialysis patients immediately before and after a haemodialysis session and in 10 control subjects. Choline uptake was measured in erythrocytes from normal and uraemic patients after washing in vitro and subsequent incubation in autologous plasma. Amines present in uraemic plasma were examined for their effect on choline transport in normal erythrocytes.. 2. NMR spectroscopy was used to measure choline, trimethylamine and dimethylamine in erythrocyte extracts from nine control subjects, 32 subjects with renal impairment and nine samples from haemodialysis patients.. 3. The increased choline influx in uraemic erythrocytes is significantly decreased by prior haemodialysis (mean Vmax pre-dialysis 146±20 μmol h−1 I−1, postdialysis 113±13 μ/mol h-1 I−1 (P , 0.005). After in vitro washing there is a fall in Vmax, and no longer any significant difference between pre- and post-dialysis samples. There remains a significant difference in the ...
Units of blood were divided into 5 aliquots and were stored at 4 C. in ACD without additive or supplemented with adenine, inosine, inosine adenine, or adenosine. Adenine and nucleoside were added in an amount of 0.75 and 15 micro moles per ml ACD-blood, respectively. After storage for 6 weeks, 24 hour post-transfusion survival of the erthrocytes was determined. Survival of the erthrocytes was significantly increased when the ACD was supplemented with any of the additives. There was, however, no significant difference in the effect of any one of the additives. The glycolytic intermediates of erythrocytes stored for the same period with the same additives were studied after separation on columns of ion-exchange resin. No adenosine triphosphate (ATP) or 2,3-diphosphoglycerate (DPG) remained in the blood stored in ACD alone. Supplementation of ACD with adenine resulted in no qualitative or quantitative change in the intermediates. ATP and DPG remained in the erythrocytes stored in ACD supplemented
Download Free Full-Text of an article CORRELATION BETWEEN SERUM AND ERYTHROCYTE SUPEROXIDE DISMUTASE WITH SERUM HOMOCYSTEINE IN MYOCARDIAL INFARCTION
levels are not well characterized. Only a few P. falciparum-derived factors have been shown to activate immune cells to produce the inflammatory responses associated with malaria. These include glycosylphosphatidylinositol (GPI) anchors and DNA-laden hemozoin (a polymer of heme moieties derived from digested hemoglobin), which are released into circulation when sequestered P. falciparum-infected red blood cells (RBCs) rupture in microvessels [5?]. These two parasite factors interact with Toll-like receptors (TLRs) 1326631 on immune cells in vitro to elicit some of the same cytokine responses associated with human malaria syndromes. Uric acid (UA) is produced in humans and higher primates as the final product of purine metabolism [9]. Its biosynthesis is catalyzed by xanthine oxidase, which produces reactive oxygen species (ROS) as by-products. Three recent studies have implicated UA as an additional parasite-derived factor that may contribute to malaria pathogenesis. In the first study, Orengo ...
Ligand uptake and release by the haemoglobin contained within adult mouse erythrocytes was studied by using dual-wavelength stopped-flow techniques. The rate of O2 uptake is very much lower than that expected for an equivalent concentration of haemoglobin in free solution. The O2-concentration-dependence found in uptake experiments is greater than first-order. CO uptake shows the same pattern of reactivity as does O2, but the associated rates of uptake are lower and the concentration-dependence of the CO rates is first-order. O2 release from the adult erythrocytes was measured by stopped-flow mixing with Na2S2O4. Under these circumstances the deoxygenation of intracellular haemoglobin shows accelerating time courses. The apparent rate-constant-dependence on dithionite concentration shows a rate limit at high reductant concentrations. Computer simulations of both ligand uptake and release processes were carried out by using a three-dimensional model. The simulations clearly indicate that in ...
The rhoptry is an organelle of the malarial merozoite which has been suggested to play a role in parasite invasion of its host cell, the erythrocyte. A monoclonal antibody selected for reactivity with this organelle identifies a parasite synthesized protein of 110 kD. From biosynthetic labeling experiments it was demonstrated that the protein is synthesized midway through the erythrocytic cycle (the trophozoite stage) but immunofluorescence indicates the protein is not localized in the organelle until the final stage (segmenter stage) of intraerythrocytic development. Immunoelectron microscopy shows that the protein is localized in the matrix of the rhoptry organelle and on membranous whorls secreted from the merozoite. mAb recognition of the protein is dithiothreitol (DTT) labile, indicating that the conformation of the epitope is dependent on a disulfide linkage. During erythrocyte reinvasion by the extracellular merozoite, immunofluorescence shows the rhoptry protein discharging from the ...
The Role of Calcium and Glucose on the Increasing of Parasitemia Value and Hemolysis into Plasmodium falciparum-infected Erythrocyte
Glycophorin both in solution and inserted into liposomes blocks invasion of erythrocytes by the malaria parasite Plasmodium falciparum. Furthermore, one sugar, N-acetyl-D-glucosamine (GlcNAc), completely blocks invasion of the erythrocyte by this parasite. GlcNAc coupled to bovine serum albumin to prevent the sugar entering infected erythrocytes was at least 100,000 times more effective than GlcNAc alone. Bovine serum albumin coupled to lactose or bovine serum albumin alone had no effect on invasion. These results suggest that the binding of P. falciparum to erythrocytes is lectin-like and is determined by carbohydrates on glycophorin.
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Alnakshbandi, Abdulkadir A. (2015) Aminoglycosides induce fragility of human red cell membrane: An in vitro study. [Publication] Full text not available from this repository ...