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Sample records for red cell discriminant

  1. A novel cell permeant and far red-fluorescing DNA probe, DRAQ5, for blood cell discrimination by flow cytometry.

    PubMed

    Smith, P J; Wiltshire, M; Davies, S; Patterson, L H; Hoy, T

    1999-10-29

    The deep red fluorescing agent (DRAQ5) is a synthetic anthraquinone with a high affinity for DNA and a high capacity to rapidly enter living cells or stain fixed cells. DRAQ5 is optimally excited by red-light emitting sources and yields a deep red emission spectrum which extends into the low infra-red. DRAQ5 shows excitation at sub-optimal wavelengths including the 488 nm line and the multi-line UV wavelengths emitted by argon-ion lasers. Single beam (488 nm) flow cytometry has been used to demonstrate the utility of DRAQ5-nuclear DNA fluorescence as a discriminating parameter for human leucocytes and lymphoma cells, in combination with fluorochrome-labelled antibodies for the detection of surface antigens and subpopulation recognition. DRAQ5 fluorescence was found to reflect cellular DNA content as evidenced by cell cycle distribution profiles for asynchronous and cell cycle-perturbed populations. Importantly, DRAQ5 can be used in combination with FITC and RPE-labelled antibodies, without the need for fluorescence compensation. PMID:10556697

  2. Evaluation of Platelet and Red Blood Cell Parameters with Proposal of Modified Score as Discriminating Guide for Iron Deficiency Anemia and β-Thalassemia Minor

    PubMed Central

    Shrivastava, Vikas; Chandra, Smita; Rawat, Anil; Nautiyal, Ruchira

    2016-01-01

    Introduction Iron Deficiency Anaemia (IDA) and β-Thalassaemia Minor (BTM) are considered to be important cause of microcytic hypochromic anaemia. Studies have evaluated various red cell parameters which are easily available on electronic cell counters for discrimination of IDA and BTM in different ethnic populations. The analysis of previously established red cell discriminative indices with new cut-off have also been done by studies which may be relevant in their set of population for differentiation. Aim The study was conducted to propose a modified score considering the established red blood cell indices with a new cut off and to formulate index taking into consideration Red Blood Cell (RBC) and platelet parameters for early differentiation of IDA and BTM. Materials and Methods The prospective study included cases with MCV< 80 fl and new modified score of 11 was proposed by statistically analysing the previous discriminative indices with new cut-off by giving score 0 for IDA and score 1 for BTM. The summation of all scores gave modified 11 T score. A new cut off for differentiation of IDA and BTM was proposed in the study by using ROC curve and analysing AUC which statistically corresponded to highest accuracy. An attempt to formulate a new index using the RBC and platelet parameters was also made for initial discrimination. Results The study included 153 cases and in addition to red blood cell parameters, mean platelet volume and platelet distribution width also showed statistical significant difference between IDA and BTM (p<0.05). Modified new 11 T score was 87.6% specific for BTM while proposed index showed 80.4% negative predictive value for BTM and correctly identified 75% of cases. Conclusion The proposed new index and modified 11T score may be used for initial discrimination of BTM and IDA especially in resource limited regions. Apart from RBC parameters, mean platelet volume and platelet distribution width may also be useful in early differentiation

  3. Red blood cell production

    MedlinePlus

    ... cells are an important element of blood. Their job is to transport oxygen to the body’s tissues in exchange for carbon dioxide, which is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts ...

  4. Red blood cell production

    MedlinePlus Videos and Cool Tools

    ... or another. Red blood cells are an important element of blood. Their job is to transport oxygen ... hemocytoblasts give rise to all of the formed elements in blood. If a hemocytoblast commits to becoming ...

  5. Red blood cells, multiple sickle cells (image)

    MedlinePlus

    Sickle cell anemia is an inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.

  6. Red blood cells, multiple sickle cells (image)

    MedlinePlus

    ... inherited disorder in which abnormal hemoglobin (the red pigment inside red blood cells) is produced. The abnormal hemoglobin causes red blood cells to assume a sickle shape, like the ones seen in this photomicrograph.

  7. Red blood cells, sickle cell (image)

    MedlinePlus

    Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). ... abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.

  8. Red blood cells, sickle cell (image)

    MedlinePlus

    Sickle cell anemia is an inherited blood disease in which the red blood cells produce abnormal pigment (hemoglobin). The abnormal hemoglobin causes deformity of the red blood cells into crescent or sickle-shapes, as seen in this photomicrograph.

  9. Red blood cells, sickle cells (image)

    MedlinePlus

    These crescent or sickle-shaped red blood cells (RBCs) are present with Sickle cell anemia, and stand out clearly against the normal round RBCs. These abnormally shaped cells may become entangled and ...

  10. Red Blood Cell Antibody Identification

    MedlinePlus

    ... be limited. Home Visit Global Sites Search Help? RBC Antibody Identification Share this page: Was this page helpful? Also known as: Alloantibody Identification; Antibody ID, RBC; RBC Ab ID Formal name: Red Blood Cell ...

  11. Rapid discrimination of Chinese red ginseng and Korean ginseng using an electronic nose coupled with chemometrics.

    PubMed

    Li, Shan; Li, Xiang-ri; Wang, Gang-li; Nie, Li-xing; Yang, Yao-jun; Wu, Hao-zhong; Wei, Feng; Zhang, Ji; Tian, Jin-gai; Lin, Rui-chao

    2012-11-01

    Red ginseng is a precious and widely used traditional Chinese medicine. At present, Chinese red ginseng and Korean ginseng are both commonly found on the market. To rapidly and nondestructively discriminate between Chinese red ginseng and Korean ginseng, an electronic nose coupled with chemometrics was developed. Different red ginseng samples, including Chinese red ginseng (n=30) and Korean ginseng (South Korean red ginseng and North Korean red ginseng n=26), were collected. The metal oxide sensors on an electronic nose were used to measure the red ginseng samples. Multivariate statistical analyses, including principal component analysis (PCA), discriminant factorial analysis (DFA) and soft independent modeling of class analogy (SIMCA), were employed. All of the samples were analyzed by PCA. Most of the samples were used to set up DFA and SIMCA models, and then the remaining samples (Nos. 9, 10, 17, 18, 29, 30, 34, 43, 44, 50, and 51) were projected onto the DFA and SIMCA models in the form of black dots to validate the models. The results indicated that Chinese red ginseng and Korean ginseng were successfully discriminated using the electronic nose coupled with PCA, DFA and SIMCA. The checking scores of the DFA and SIMCA models were 100. The samples projected onto the DFA and SIMCA models were all correctly discriminated. The DFA and SIMCA models were robust. Electronic nose technology is a rapid, accurate, sensitive and nondestructive method to discriminate between Chinese red ginseng and Korean ginseng. PMID:22742921

  12. Red cell metabolism studies on Skylab

    NASA Technical Reports Server (NTRS)

    Mengel, C. E.

    1977-01-01

    Blood samples from Spacelab crewmembers were studied for possible environment effects on red cell components. Analysis involved peroxidation of red cell lipids, enzymes of red cell metabolism, and levels of 2,3-diphosphoglyceric acid and adenosine triphosphate. Results show that there is no evidence of lipid peroxidation, that biochemical effect known to be associated with irreversible red cell damage. Changes observed in glycolytic intermediates and enzymes cannot be directly implicated as indicating evidence of red cell damage.

  13. [Discrimination of Red Tide algae by fluorescence spectra and principle component analysis].

    PubMed

    Su, Rong-guo; Hu, Xu-peng; Zhang, Chuan-song; Wang, Xiu-lin

    2007-07-01

    Fluorescence discrimination technology for 11 species of the Red Tide algae at genus level was constructed by principle component analysis and non-negative least squares. Rayleigh and Raman scattering peaks of 3D fluorescence spectra were eliminated by Delaunay triangulation method. According to the results of Fisher linear discrimination, the first principle component score and the second component score of 3D fluorescence spectra were chosen as discriminant feature and the feature base was established. The 11 algae species were tested, and more than 85% samples were accurately determinated, especially for Prorocentrum donghaiense, Skeletonema costatum, Gymnodinium sp., which have frequently brought Red tide in the East China Sea. More than 95% samples were right discriminated. The results showed that the genus discriminant feature of 3D fluorescence spectra of Red Tide algae given by principle component analysis could work well. PMID:17891964

  14. Red cell DAMPs and inflammation.

    PubMed

    Mendonça, Rafaela; Silveira, Angélica A A; Conran, Nicola

    2016-09-01

    Intravascular hemolysis, or the destruction of red blood cells in the circulation, can occur in numerous diseases, including the acquired hemolytic anemias, sickle cell disease and β-thalassemia, as well as during some transfusion reactions, preeclampsia and infections, such as those caused by malaria or Clostridium perfringens. Hemolysis results in the release of large quantities of red cell damage-associated molecular patterns (DAMPs) into the circulation, which, if not neutralized by innate protective mechanisms, have the potential to activate multiple inflammatory pathways. One of the major red cell DAMPs, heme, is able to activate converging inflammatory pathways, such as toll-like receptor signaling, neutrophil extracellular trap formation and inflammasome formation, suggesting that this DAMP both activates and amplifies inflammation. Other potent DAMPs that may be released by the erythrocytes upon their rupture include heat shock proteins (Hsp), such as Hsp70, interleukin-33 and Adenosine 5' triphosphate. As such, hemolysis represents a major inflammatory mechanism that potentially contributes to the clinical manifestations that have been associated with the hemolytic diseases, such as pulmonary hypertension and leg ulcers, and likely plays a role in specific complications of sickle cell disease such as endothelial activation, vaso-occlusive processes and tissue injury. PMID:27251171

  15. Red cell distribution width and nonalcoholic steatohepatitis

    PubMed Central

    Gulcan Kurt, Yasemin; Cayci, Tuncer; Aydin, Fevzi Nuri; Agilli, Mehmet

    2014-01-01

    Red cell distribution width is a measure of deviation of the volume of red blood cells. It is a marker of anisocytosis and often used to evaluate the possible causes of anemia. Elevated red cell distribution width levels are also associated with acute and chronic inflammatory responses. In nonalcoholic steatohepatitis, inflammation is accompanied with steatosis. For assuming red cell distribution width as a marker of nonalcoholic steatohepatitis, intervening factors such as levels of inflammatory markers should also be evaluated. PMID:25473202

  16. SENTINEL-2A red-edge spectral indices suitability for discriminating burn severity

    NASA Astrophysics Data System (ADS)

    Fernández-Manso, Alfonso; Fernández-Manso, Oscar; Quintano, Carmen

    2016-08-01

    Fires are a problematic and recurrent issue in Mediterranean ecosystems. Accurate discrimination between burn severity levels is essential for the rehabilitation planning of burned areas. Sentinel-2A MultiSpectral Instrument (MSI) record data in three red-edge wavelengths, spectral domain especially useful on agriculture and vegetation applications. Our objective is to find out whether Sentinel-2A MSI red-edge wavelengths are suitable for burn severity discrimination. As study area, we used the 2015 Sierra Gata wildfire (Spain) that burned approximately 80 km2. A Copernicus Emergency Management Service (EMS)-grading map with four burn severity levels was considered as reference truth. Cox and Snell, Nagelkerke and McFadde pseudo-R2 statistics obtained by Multinomial Logistic Regression showed the superiority of red-edge spectral indices (particularly, Modified Simple Ratio Red-edge, Chlorophyll Index Red-edge, Normalized Difference Vegetation Index Red-edge) over conventional spectral indices. Fisher's Least Significant Difference test confirmed that Sentinel-2A MSI red-edge spectral indices are adequate to discriminate four burn severity levels.

  17. What is red cell deformability?

    PubMed

    Schmid-Schönbein, H; Gaehtgens, P

    1981-01-01

    Microscopic flow visualization of the process of red cell adaptation to flow shows that red cell deformation in flow is the consequence of a continuous viscous rather than an elastic deformation. This fluid drop-like adaptation primarily depends on: (a) the fluidity of the cytoplasm and (b) the favourable surface-area-to-volume ratio, with an excess of surface area allowing strong deformations without an increase in surface area (a real strain). (c) In contrast to previous notions, the modulus of shear elasticity of the membrane is probably less significant. After many attempts to differentiate the contribution of bending and shear stiffness to the elastic recovery of the normal biconcave cell shape have not produced equivocal results, we have changed the elastic shear modulus experimentally by cross-linking the spectrin using the membrane-permeant, bifunctional SH-reagent DIAMIDE, which allows to increase the elastic shear modulus in a dose-dependent manner. Despite a 25-fold decrease in compliance the DIAMIDE-treated cells have normal shape and show remarkably small changes in the rheological behaviour when tested in vitro and in vivo. PMID:6948373

  18. Chemical toxicity of red cells.

    PubMed Central

    Piomelli, S

    1981-01-01

    Exposure to toxic chemicals may result in alterations of red cell function. In certain cases, the toxic effect requires a genetic predisposition and thus affects only a restricted number of individuals; in other instances, the toxic effect is exerted on the hematopoietic system of every person. Glucose-6-phosphate dehydrogenase deficiency is probably the most widespread genetic disorder. It is observed at highest frequency in populations from subtropical countries as a result of its selective advantage vis à vis falciparum malaria. The gene controlling this enzyme is located on the X-chromosome; thus, the defect is sex-linked. Individuals with a genetic defect of this enzyme are extremely susceptible to hemolysis, when exposed to oxidant drugs (such as certain antimalarials and sulfonamides) because of the inability of their red cells to regenerate NADPH. Lead poisoning result in profound effects on the process of heme synthesis. Among the steps most sensitive to lead toxicity are the enzyme delta-aminolevulinic acid dehydratase and the intramitochondrial step that leads to the incorporation of iron into protoporphyrin. By these mechanisms, in severe lead intoxication there is an accumulation of large amounts of delta-aminolevulinic acid (a compound with inherent neurotoxicity), and there are abnormalities of mitochondrial function in all cells of the body. Individuals living in an industrialized society are unavoidably exposed to some environmental lead. Recent evidence indicates that, even at levels of exposure which do not increase the blood lead level above values presently considered normal, abnormalities of heme synthesis are clearly detectable. PMID:7016524

  19. Inflight Assay of Red Blood Cell Deformability

    NASA Technical Reports Server (NTRS)

    Ingram, M.; Paglia, D. E.; Eckstein, E. C.; Frazer, R. E.

    1985-01-01

    Studies on Soviet and American astronauts have demonstrated that red blood cell production is altered in response to low gravity (g) environment. This is associated with changes in individual red cells including increased mean cell volume and altered membrane deformability. During long orbital missions, there is a tendency for the red cell mass deficit to be at least partly corrected although the cell shape anomalies are not. Data currently available suggest that the observed decrease in red cell mass is the result of sudden suppression of erythropoieses and that the recovery trend observed during long missions reflects re-establishment of erythropoietic homeostasis at a "set point" for the red cell mass that is slightly below the normal level at 1 g.

  20. Red blood cell membrane defects.

    PubMed

    Iolascon, Achille; Perrotta, Silverio; Stewart, Gordon W

    2003-03-01

    We present an overview of the currently known molecular basis of red cell membrane disorders. A detailed discussion of the structure of the red cell membrane and the pathophysiology and clinical aspects of its disorders is reported. Generally speaking, hereditary spherocytosis (HS) results from a loss of erythrocyte surface area. The mutations of most cases of HS are located in the following genes: ANK1, SPTB, SLC4A1, EPB42 and SPTA1, which encode for ankyrin, spectrin beta-chain, the anion exchanger 1 (band 3), protein 4.2 and spectrin alpha-chain, respectively. Hereditary elliptocytosis (HE) reflects a diminished elasticity of the skeleton. Its aggravated form, hereditary pyropoikilocytosis (HPP), implies that the skeleton undergoes further destabilization. The mutations responsible for HE and HPP, lie in the SPTA1 and SPTB gene, and in the EPB41 gene encoding protein 4.1. Allele alpha LELY is a common polymorphic allele, which plays the role of an aggravating factor when it occurs in trans of an elliptocytogenic allele of the SPTA1 gene. Southeast Asian ovalocytosis derives from a change in band 3. The genetic disorders of membrane permeability to monovalent cations required a positional cloning approach. In this respect, channelopathies represent a new frontier in the field. Dehydrated hereditary stomatocytosis (DHS) was shown to belong to a pleiotropic syndrome: DHS + fetal edema + pseudohyperkalemia, which maps 16q23-24. Splenectomy is strictly contraindicated in DHS and another disease of the same class, overhydrated hereditary stomatocytosis, because it increases the risk of thromboembolic accidents. PMID:14692233

  1. Rapid discrimination of main red meat species based on near-infrared hyperspectral imaging technology

    NASA Astrophysics Data System (ADS)

    Qiao, Lu; Peng, Yankun; Chao, Kuanglin; Qin, Jianwei

    2016-05-01

    Meat is the necessary source of essential nutrients for people including protein, fat, and so on. The discrimination of meat species and the determination of meat authenticity have been an important issue in the meat industry. The objective of this study is to realize the fast and accurate identification of three main red meats containing beef, lamb and pork by using near-infrared hyperspectral imaging (HSI) technology. After acquiring the hyperspectral images of meat samples, the calibration of acquired images and selection of the region of interest (ROI) were carried out. Then spectral preprocessing method of standard normal variate correction (SNV) was used to reduce the light scattering and random noise before the spectral analysis. Finally, characteristic wavelengths were extracted by principal component analysis (PCA), and the Fisher linear discriminant method was applied to establish Fisher discriminant functions to identify the meat species. All the samples were collected from different batches in order to improve the coverage of the models. In addition to the validation of sample itself in train set and cross validation, three different meat samples were sliced at the size of 2cm×2cm×2 cm approximately and were spliced together in one interface to be scanned by HSI system. The acquired hyperspectral data was applied to further validate the discriminant model. The results demonstrated that the near-infrared hyperspectral imaging technology could be applied as an effective, rapid and non-destructive discrimination method for main red meats.

  2. RED: a red-cell antibody identification expert module.

    PubMed

    Smith, J W; Svirbely, J R; Evans, C A; Strohm, P; Josephson, J R; Tanner, M

    1985-06-01

    We describe a software module in an expert system RED, which interprets data related to red cell antibody identification. There are three portions to this module: the problem-solving component, which incorporates the knowledge required for antibody identification as a hierarchy of programs. The programs in the hierarchy organize within themselves small pieces of knowledge represented in the form of production rules, which are capable of making judgments concerning a specific hypothesis; an intelligent data base for storage of patient data, red cell attributes, and test results; the "overview critic" portion, which combines the atomic hypotheses judged favorably by the antibody programs into a unified judgment concerning the case. Overview makes the decision to terminate processing with a conclusion about which antibodies are actually present and what specific further tests need to be performed to resolve any remaining ambiguities. PMID:3840517

  3. Red blood cell decreases of microgravity

    NASA Technical Reports Server (NTRS)

    Johnson, P. C.

    1985-01-01

    Postflight decreases in red blood cell mass (RBCM) have regularly been recorded after exposure to microgravity. These 5-25 percent decreases do not relate to the mission duration, workload, caloric intake or to the type of spacecraft used. The decrease is accompanied by normal red cell survivals, increased ferritin levels, normal radioactive iron studies, and increases in mean red blood cell volume. Comparable decreases in red blood cell mass are not found after bed rest, a commonly used simulation of the microgravity state. Inhibited bone marrow erythropoiesis has not been proven to date, although reticulocyte numbers in the peripheral circulation are decreased about 50 percent. To date, the cause of the microgravity induced decreases in RBCM is unknown. Increased splenic trapping of circulating red blood cells seem the most logical way to explain the results obtained.

  4. 21 CFR 640.10 - Red Blood Cells.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells...

  5. 21 CFR 640.10 - Red Blood Cells.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells...

  6. 21 CFR 640.10 - Red Blood Cells.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells...

  7. 21 CFR 640.10 - Red Blood Cells.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells...

  8. 21 CFR 640.10 - Red Blood Cells.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Red Blood Cells. 640.10 Section 640.10 Food and... ADDITIONAL STANDARDS FOR HUMAN BLOOD AND BLOOD PRODUCTS Red Blood Cells § 640.10 Red Blood Cells. The proper name of this product shall be Red Blood Cells. The product is defined as red blood cells...

  9. Red cell membrane: past, present, and future

    PubMed Central

    Gallagher, Patrick G.

    2008-01-01

    As a result of natural selection driven by severe forms of malaria, 1 in 6 humans in the world, more than 1 billion people, are affected by red cell abnormalities, making them the most common of the inherited disorders. The non-nucleated red cell is unique among human cell type in that the plasma membrane, its only structural component, accounts for all of its diverse antigenic, transport, and mechanical characteristics. Our current concept of the red cell membrane envisions it as a composite structure in which a membrane envelope composed of cholesterol and phospholipids is secured to an elastic network of skeletal proteins via transmembrane proteins. Structural and functional characterization of the many constituents of the red cell membrane, in conjunction with biophysical and physiologic studies, has led to detailed description of the way in which the remarkable mechanical properties and other important characteristics of the red cells arise, and of the manner in which they fail in disease states. Current studies in this very active and exciting field are continuing to produce new and unexpected revelations on the function of the red cell membrane and thus of the cell in health and disease, and shed new light on membrane function in other diverse cell types. PMID:18988878

  10. Theoretical models for near forward light scattering by a Plasmodium falciparum infected red blood cell

    NASA Astrophysics Data System (ADS)

    Sharma, S. K.

    2012-12-01

    A number of experimental elastic light scattering studies have been performed in the past few years with the aim of developing automated in vivo tools for differentiating a healthy red blood cell from a Plasmodium falciparum infected cell. This paper examines some theoretical aspects of the problem. An attempt has been made to simulate the scattering patterns of healthy as well as infected individual red blood cells. Two models, namely, a homogeneous sphere model and a coated sphere model have been considered. The scattering patterns predicted by these models are examined. A possible method for discriminating infected red blood cells from healthy ones has been suggested.

  11. Viscoelastic transient of confined red blood cells.

    PubMed

    Prado, Gaël; Farutin, Alexander; Misbah, Chaouqi; Bureau, Lionel

    2015-05-01

    The unique ability of a red blood cell to flow through extremely small microcapillaries depends on the viscoelastic properties of its membrane. Here, we study in vitro the response time upon flow startup exhibited by red blood cells confined into microchannels. We show that the characteristic transient time depends on the imposed flow strength, and that such a dependence gives access to both the effective viscosity and the elastic modulus controlling the temporal response of red cells. A simple theoretical analysis of our experimental data, validated by numerical simulations, further allows us to compute an estimate for the two-dimensional membrane viscosity of red blood cells, η(mem)(2D) ∼ 10(-7) N ⋅ s ⋅ m(-1). By comparing our results with those from previous studies, we discuss and clarify the origin of the discrepancies found in the literature regarding the determination of η(mem)(2D), and reconcile seemingly conflicting conclusions from previous works. PMID:25954871

  12. Avoiding Anemia: Boost Your Red Blood Cells

    MedlinePlus

    ... link, please review our exit disclaimer . Subscribe Avoiding Anemia Boost Your Red Blood Cells If you’re ... and sluggish, you might have a condition called anemia. Anemia is a common blood disorder that many ...

  13. Phosphatidylserine exposure and red cell viability in red cell aging and in hemolytic anemia

    PubMed Central

    Boas, Franz Edward; Forman, Linda; Beutler, Ernest

    1998-01-01

    Phosphatidylserine (PS) normally localizes to the inner leaflet of cell membranes but becomes exposed in abnormal or apoptotic cells, signaling macrophages to ingest them. Along similar lines, it seemed possible that the removal of red cells from circulation because of normal aging or in hemolytic anemias might be triggered by PS exposure. To investigate the role of PS exposure in normal red cell aging, we used N-hydroxysuccinimide-biotin to tag rabbit red cells in vivo, then used phycoerythrin-streptavidin to label the biotinylated cells, and annexin V-fluorescein isothiocyanate (FITC) to detect the exposed PS. Flow cytometric analysis of these cells drawn at 10-day intervals up to 70 days after biotinylation indicated that older, biotinylated cells expose more PS. Furthermore, our data match a simple model of red cell senescence that assumes both an age-dependent destruction of senescent red cells preceded by several hours of PS exposure and a random destruction of red cells without PS exposure. By using this model, we demonstrated that the exposure of PS parallels the rate at which biotinylated red cells are removed from circulation. On the other hand, using an annexin V-FITC label and flow cytometry demonstrates that exposed PS does not cause the reduced red cell life span of patients with hemolytic anemia, with the possible exception of those with unstable hemoglobins or sickle cell anemia. Thus, in some cases PS exposure on the cell surface may signal the removal of red cells from circulation, but in other cases some other signal must trigger the sequestration of cells. PMID:9501218

  14. 21 CFR 864.8540 - Red cell lysing reagent.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Red cell lysing reagent. 864.8540 Section 864.8540...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8540 Red cell lysing reagent. (a) Identification. A red cell lysing reagent is a device used to lyse (destroy) red blood cells...

  15. 21 CFR 864.8540 - Red cell lysing reagent.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Red cell lysing reagent. 864.8540 Section 864.8540...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8540 Red cell lysing reagent. (a) Identification. A red cell lysing reagent is a device used to lyse (destroy) red blood cells...

  16. 21 CFR 864.8540 - Red cell lysing reagent.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Red cell lysing reagent. 864.8540 Section 864.8540...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8540 Red cell lysing reagent. (a) Identification. A red cell lysing reagent is a device used to lyse (destroy) red blood cells...

  17. 21 CFR 864.8540 - Red cell lysing reagent.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Red cell lysing reagent. 864.8540 Section 864.8540...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8540 Red cell lysing reagent. (a) Identification. A red cell lysing reagent is a device used to lyse (destroy) red blood cells...

  18. 21 CFR 864.8540 - Red cell lysing reagent.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Red cell lysing reagent. 864.8540 Section 864.8540...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Reagents § 864.8540 Red cell lysing reagent. (a) Identification. A red cell lysing reagent is a device used to lyse (destroy) red blood cells...

  19. 21 CFR 864.5300 - Red cell indices device.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  20. 21 CFR 864.5300 - Red cell indices device.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  1. 21 CFR 864.5300 - Red cell indices device.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  2. 21 CFR 864.5300 - Red cell indices device.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  3. 21 CFR 864.5300 - Red cell indices device.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Red cell indices device. 864.5300 Section 864.5300....5300 Red cell indices device. (a) Identification. A red cell indices device, usually part of a larger... corpuscular hemoglobin (MCH), and the mean corpuscular hemoglobin concentration (MCHC). The red cell...

  4. A web-server of cell type discrimination system.

    PubMed

    Wang, Anyou; Zhong, Yan; Wang, Yanhua; He, Qianchuan

    2014-01-01

    Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and somatic cells (SCs). Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells. PMID:24578634

  5. A Web-Server of Cell Type Discrimination System

    PubMed Central

    Zhong, Yan

    2014-01-01

    Discriminating cell types is a daily request for stem cell biologists. However, there is not a user-friendly system available to date for public users to discriminate the common cell types, embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs), and somatic cells (SCs). Here, we develop WCTDS, a web-server of cell type discrimination system, to discriminate the three cell types and their subtypes like fetal versus adult SCs. WCTDS is developed as a top layer application of our recent publication regarding cell type discriminations, which employs DNA-methylation as biomarkers and machine learning models to discriminate cell types. Implemented by Django, Python, R, and Linux shell programming, run under Linux-Apache web server, and communicated through MySQL, WCTDS provides a friendly framework to efficiently receive the user input and to run mathematical models for analyzing data and then to present results to users. This framework is flexible and easy to be expended for other applications. Therefore, WCTDS works as a user-friendly framework to discriminate cell types and subtypes and it can also be expended to detect other cell types like cancer cells. PMID:24578634

  6. Red cell metabolism studies on Skylab

    NASA Technical Reports Server (NTRS)

    Mengel, C. E.

    1974-01-01

    On the basis of these background data, metabolic studies were performed on humans involved in space flight. These studies included the Skylab experiences. The primary purpose of the investigations was to study red cells for: (1) evidences of lipid peroxidation, or (2) changes at various points in the glycolytic pathway. The Skylab missions were an opportunity to study blood samples before, during, and after flight and to compare results with simultaneous controls. No direct evidence that lipid peroxidation had occurred in the red blood cells was apparent in the studies.

  7. Viscoelastic Transient of Confined Red Blood Cells

    PubMed Central

    Prado, Gaël; Farutin, Alexander; Misbah, Chaouqi; Bureau, Lionel

    2015-01-01

    The unique ability of a red blood cell to flow through extremely small microcapillaries depends on the viscoelastic properties of its membrane. Here, we study in vitro the response time upon flow startup exhibited by red blood cells confined into microchannels. We show that the characteristic transient time depends on the imposed flow strength, and that such a dependence gives access to both the effective viscosity and the elastic modulus controlling the temporal response of red cells. A simple theoretical analysis of our experimental data, validated by numerical simulations, further allows us to compute an estimate for the two-dimensional membrane viscosity of red blood cells, ηmem2D ∼ 10−7 N⋅s⋅m−1. By comparing our results with those from previous studies, we discuss and clarify the origin of the discrepancies found in the literature regarding the determination of ηmem2D, and reconcile seemingly conflicting conclusions from previous works. PMID:25954871

  8. Discrimination of different red wine by Fourier-transform infrared and two-dimensional infrared correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-ling; Chen, Jian-bo; Lei, Yu; Zhou, Qun; Sun, Su-qin; Noda, Isao

    2010-06-01

    Fourier-transform infrared spectroscopy (FT-IR) and two-dimensional infrared (2D IR) correlation spectroscopy were applied to analyze main components of liquid red wine with different sugar contents and volatilization residues of dry red wine from different manufactures. The infrared spectra, second derivative spectra of dry red wine show the typical peaks of alcohol, while the spectra of sweet wine are composed of the peaks of both alcohol and sugar, and the contribution of sugar enhanced as the increase of sugar content. Using principal component analysis (PCA) method, dry and sweet wine can be readily classified. Analysis of the infrared spectra of the volatilization residues of dry red wine samples from five different manufactures indicates that dry red wine may be composed of glycerol, carboxylic acids or esters and carboxyl ate, at the same time, different dry red wine show different characteristic peaks in the second derivative spectra and 2D IR correlation spectra, which can be used to discriminate the different manufactures and evaluate the quality of wine samples. The results suggested that infrared spectroscopy is a direct and effective method for the analysis of principle components of different red wines and discrimination of different red wines.

  9. In vitro red blood cell assay for oxidant toxicity of petroleum oil

    SciTech Connect

    Couillard, C.M.; Leighton, F.A. )

    1993-05-01

    Petroleum oil has caused hemolytic anemia in birds and mammals. In birds, an oxidant damage on circulating red cells has been identified as the primary toxic effect of ingested petroleum oils. An in vitro red blood cell assay was developed to discriminate among the oxidant activities of different petroleum oils. The assay used rabbit red blood cells with a rat liver enzyme system and formation of methemoglobin was measured as an indicator of oxidant damage to the red cells. The assay was applied to five different petroleum oils and to naphthalene, a petroleum hydrocarbon known to cause hemolytic anemia. Different petroleum oils differed in their capacity to induce methemoglobin formation. Methemoglobin levels varied from 2.9% with Arabian light crude oil to 6.2% with South Louisiana crude oil. Naphthalene induced formation of up to 37% methemoglobin. Naphthalene and the five petroleum oils generated methemoglobin only in the presence of liver enzymes.

  10. 21 CFR 864.8185 - Calibrator for red cell and white cell counting.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Calibrator for red cell and white cell counting... Calibrator for red cell and white cell counting. (a) Identification. A calibrator for red cell and white cell counting is a device that resembles red or white blood cells and that is used to set instruments...

  11. 21 CFR 864.8185 - Calibrator for red cell and white cell counting.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Calibrator for red cell and white cell counting... Calibrator for red cell and white cell counting. (a) Identification. A calibrator for red cell and white cell counting is a device that resembles red or white blood cells and that is used to set instruments...

  12. 21 CFR 864.8185 - Calibrator for red cell and white cell counting.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Calibrator for red cell and white cell counting... Calibrator for red cell and white cell counting. (a) Identification. A calibrator for red cell and white cell counting is a device that resembles red or white blood cells and that is used to set instruments...

  13. 21 CFR 864.8185 - Calibrator for red cell and white cell counting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Calibrator for red cell and white cell counting... Calibrator for red cell and white cell counting. (a) Identification. A calibrator for red cell and white cell counting is a device that resembles red or white blood cells and that is used to set instruments...

  14. 21 CFR 864.8185 - Calibrator for red cell and white cell counting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Calibrator for red cell and white cell counting... Calibrator for red cell and white cell counting. (a) Identification. A calibrator for red cell and white cell counting is a device that resembles red or white blood cells and that is used to set instruments...

  15. Determination of Fc function with frozen red blood cells.

    PubMed

    Gurevich, V; Bertolini, J; Lyons, K

    2006-09-01

    The Fc function of immunoglobulins is commonly determined by an assay based on monitoring immunoglobulin induced, complement mediated red cell lysis. This assay requires a continuous source of fresh red cells. We have shown that the assay can be successfully performed with frozen red cells. The possibility of access to a stored standard stock of red cells will improve the convenience of performing the assay and could contribute to improved assay reproducibility. PMID:16500112

  16. 21 CFR 864.7100 - Red blood cell enzyme assay.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Red blood cell enzyme assay. 864.7100 Section 864... enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity in... kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme...

  17. 21 CFR 864.7100 - Red blood cell enzyme assay.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Red blood cell enzyme assay. 864.7100 Section 864... enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity in... kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme...

  18. 21 CFR 864.7100 - Red blood cell enzyme assay.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Red blood cell enzyme assay. 864.7100 Section 864... enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity in... kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme...

  19. 21 CFR 864.7100 - Red blood cell enzyme assay.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Red blood cell enzyme assay. 864.7100 Section 864... enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity in... kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme...

  20. 21 CFR 864.7100 - Red blood cell enzyme assay.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Red blood cell enzyme assay. 864.7100 Section 864... enzyme assay. (a) Identification. Red blood cell enzyme assay is a device used to measure the activity in... kinase or 2,3-diphosphoglycerate. A red blood cell enzyme assay is used to determine the enzyme...

  1. 21 CFR 660.30 - Reagent Red Blood Cells.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... identify human blood-group antibodies. (b) Source. Reagent Red Blood Cells shall be prepared from human... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Reagent Red Blood Cells. 660.30 Section 660.30...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells §...

  2. 21 CFR 660.30 - Reagent Red Blood Cells.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Reagent Red Blood Cells. 660.30 Section 660.30...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.30 Reagent Red Blood Cells. (a) Proper name and definition. The proper name of the product shall...

  3. 21 CFR 660.30 - Reagent Red Blood Cells.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Reagent Red Blood Cells. 660.30 Section 660.30...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.30 Reagent Red Blood Cells. (a) Proper name and definition. The proper name of the product shall...

  4. 21 CFR 660.30 - Reagent Red Blood Cells.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Reagent Red Blood Cells. 660.30 Section 660.30...) BIOLOGICS ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.30 Reagent Red Blood Cells. (a) Proper name and definition. The proper name of the product shall...

  5. 21 CFR 660.30 - Reagent Red Blood Cells.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Reagent Red Blood Cells. 660.30 Section 660.30 Food... ADDITIONAL STANDARDS FOR DIAGNOSTIC SUBSTANCES FOR LABORATORY TESTS Reagent Red Blood Cells § 660.30 Reagent Red Blood Cells. (a) Proper name and definition. The proper name of the product shall be Reagent...

  6. Responder individuality in red blood cell alloimmunization.

    PubMed

    Körmöczi, Günther F; Mayr, Wolfgang R

    2014-11-01

    Many different factors influence the propensity of transfusion recipients and pregnant women to form red blood cell alloantibodies (RBCA). RBCA may cause hemolytic transfusion reactions, hemolytic disease of the fetus and newborn and may be a complication in transplantation medicine. Antigenic differences between responder and foreign erythrocytes may lead to such an immune answer, in part with suspected specific HLA class II associations. Biochemical and conformational characteristics of red blood cell (RBC) antigens, their dose (number of transfusions and pregnancies, absolute number of antigens per RBC) and the mode of exposure impact on RBCA rates. In addition, individual circumstances determine the risk to form RBCA. Responder individuality in terms of age, sex, severity of underlying disease, disease- or therapy-induced immunosuppression and inflammation are discussed with respect to influencing RBC alloimmunization. For particular high-risk patients, extended phenotype matching of transfusion and recipient efficiently decreases RBCA induction and associated clinical risks. PMID:25670932

  7. Multiscale simulation of red blood cell aggregation

    NASA Astrophysics Data System (ADS)

    Bagchi, P.; Popel, A. S.

    2004-11-01

    In humans and other mammals, aggregation of red blood cells (RBC) is a major determinant to blood viscosity in microcirculation under physiological and pathological conditions. Elevated levels of aggregation are often related to cardiovascular diseases, bacterial infection, diabetes, and obesity. Aggregation is a multiscale phenomenon that is governed by the molecular bond formation between adjacent cells, morphological and rheological properties of the cells, and the motion of the extra-cellular fluid in which the cells circulate. We have developed a simulation technique using front tracking methods for multiple fluids that includes the multiscale characteristics of aggregation. We will report the first-ever direct computer simulation of aggregation of deformable cells in shear flows. We will present results on the effect of shear rate, strength of the cross-bridging bonds, and the cell rheological properties on the rolling motion, deformation and subsequent breakage of an aggregate.

  8. Reversibility of red blood cell deformation

    NASA Astrophysics Data System (ADS)

    Zeitz, Maria; Sens, P.

    2012-05-01

    The ability of cells to undergo reversible shape changes is often crucial to their survival. For red blood cells (RBCs), irreversible alteration of the cell shape and flexibility often causes anemia. Here we show theoretically that RBCs may react irreversibly to mechanical perturbations because of tensile stress in their cytoskeleton. The transient polymerization of protein fibers inside the cell seen in sickle cell anemia or a transient external force can trigger the formation of a cytoskeleton-free membrane protrusion of μm dimensions. The complex relaxation kinetics of the cell shape is shown to be responsible for selecting the final state once the perturbation is removed, thereby controlling the reversibility of the deformation. In some case, tubular protrusion are expected to relax via a peculiar “pearling instability.”

  9. Red blood cell transfusion in newborn infants.

    PubMed

    Whyte, Robin K; Jefferies, Ann L

    2014-04-01

    Red blood cell transfusion is an important and frequent component of neonatal intensive care. The present position statement addresses the methods and indications for red blood cell transfusion of the newborn, based on a review of the current literature. The most frequent indications for blood transfusion in the newborn are the acute treatment of perinatal hemorrhagic shock and the recurrent correction of anemia of prematurity. Perinatal hemorrhagic shock requires immediate treatment with large quantities of red blood cells; the effects of massive transfusion on other blood components must be considered. Some guidelines are now available from clinical trials investigating transfusion in anemia of prematurity; however, considerable uncertainty remains. There is weak evidence that cognitive impairment may be more severe at follow-up in extremely low birth weight infants transfused at lower hemoglobin thresholds; therefore, these thresholds should be maintained by transfusion therapy. Although the risks of transfusion have declined considerably in recent years, they can be minimized further by carefully restricting neonatal blood sampling. PMID:24855419

  10. From Red Cells to Soft Porous Lubrication

    NASA Astrophysics Data System (ADS)

    Wu, Qianhong; Gacka, Thomas; Nathan, Rungun; Crawford, Robert; Vucbmss Team

    2014-11-01

    Biological scientists have wondered, since the motion of red cells was first observed in capillaries, how the highly flexible red cell can move with so little friction in tightly fitting microvessels without being damaged or undergoing hemolysis. Theoretical studies (Feng and Weinbaum, 2000, JFM; Wu et al., 2004, PRL) attributed this frictionless motion to the dramatically enhanced hydrodynamic lifting force generated inside the soft, porous, endothelial surface layer (ESL) covering the inner surfaces of our capillaries, as a red blood cell glides over it. Herein we report the first experimental examination of this concept. The results conclusively demonstrate that significant fraction of the overall lifting force generated in a soft porous layer as a planing surface glides over it, is contributed by the pore fluid pressure, and thus frictional loss is reduced significantly. Moreover, the experimental predictions showed excellent agreement with the experimental data. This finding has the potential of dramatically changing existing lubrication approaches, and can result in substantial savings in energy consumption and thus reduction in greenhouse gas emissions.

  11. Neocytolysis: physiological down-regulator of red-cell mass

    NASA Technical Reports Server (NTRS)

    Alfrey, C. P.; Rice, L.; Udden, M. M.; Driscoll, T. B.

    1997-01-01

    It is usually considered that red-cell mass is controlled by erythropoietin-driven bone marrow red-cell production, and no physiological mechanisms can shorten survival of circulating red cells. In adapting to acute plethora in microgravity, astronauts' red-cell mass falls too rapidly to be explained by diminished red-cell production. Ferrokinetics show no early decline in erythropolesis, but red cells radiolabelled 12 days before launch survive normally. Selective destruction of the youngest circulating red cells-a process we call neocytolysis-is the only plausible explanation. A fall in erythropoietin below a threshold is likely to initiate neocytolysis, probably by influencing surface-adhesion molecules. Recognition of neocytolysis will require re-examination of the pathophysiology and treatment of several blood disorders, including the anaemia of renal disease.

  12. Improved discrimination among similar agricultural plots using red-and-green-based pseudo-colour imaging

    NASA Astrophysics Data System (ADS)

    Doi, Ryoichi

    2016-04-01

    The effects of a pseudo-colour imaging method were investigated by discriminating among similar agricultural plots in remote sensing images acquired using the Airborne Visible/Infrared Imaging Spectrometer (Indiana, USA) and the Landsat 7 satellite (Fergana, Uzbekistan), and that provided by GoogleEarth (Toyama, Japan). From each dataset, red (R)-green (G)-R-G-blue yellow (RGrgbyB), and RGrgby-1B pseudo-colour images were prepared. From each, cyan, magenta, yellow, key black, L*, a*, and b* derivative grayscale images were generated. In the Airborne Visible/Infrared Imaging Spectrometer image, pixels were selected for corn no tillage (29 pixels), corn minimum tillage (27), and soybean (34) plots. Likewise, in the Landsat 7 image, pixels representing corn (73 pixels), cotton (110), and wheat (112) plots were selected, and in the GoogleEarth image, those representing soybean (118 pixels) and rice (151) were selected. When the 14 derivative grayscale images were used together with an RGB yellow grayscale image, the overall classification accuracy improved from 74 to 94% (Airborne Visible/Infrared Imaging Spectrometer), 64 to 83% (Landsat), or 77 to 90% (GoogleEarth). As an indicator of discriminatory power, the kappa significance improved 1018-fold (Airborne Visible/Infrared Imaging Spectrometer) or greater. The derivative grayscale images were found to increase the dimensionality and quantity of data. Herein, the details of the increases in dimensionality and quantity are further analysed and discussed.

  13. Red Rain Cells Recovered from Interior of the Polonnaruwa Meteorite

    NASA Astrophysics Data System (ADS)

    Wickramarathne, K.; Wickramasinghe, N. C.

    2013-03-01

    Red rain cells were discovered in extracts from the Polonnaruwa (Aralaganwila) meteorite that fell nearly ten days before a red rain event in the same location in Sri Lanka. A causal connection is speculated.

  14. Anesthetics and red blood cell rheology

    NASA Astrophysics Data System (ADS)

    Aydogan, Burcu; Aydogan, Sami

    2014-05-01

    There are many conditions where it is useful for anesthetists to have a knowledge of blood rheology. Blood rheology plays an important role in numerous clinical situations. Hemorheologic changes may significantly affect the induction and recovery times with anesthetic agents. But also, hemorheologic factors are directly or indirectly affected by many anesthetic agents or their metabolites. In this review, the blood rheology with special emphasis on its application in anesthesiology, the importance hemorheological parameters in anesthesiology and also the effect of some anesthetic substances on red blood cell rheology were presented.

  15. Marker-free cell discrimination by holographic optical tweezers

    NASA Astrophysics Data System (ADS)

    Schaal, F.; Warber, M.; Zwick, S.; van der Kuip, H.; Haist, T.; Osten, W.

    2009-06-01

    We introduce a method for marker-free cell discrimination based on optical tweezers. Cancerous, non-cancerous, and drug-treated cells could be distinguished by measuring the trapping forces using holographic optical tweezers. We present trapping force measurements on different cell lines: normal pre-B lymphocyte cells (BaF3; "normal cells"), their Bcr-Abl transformed counterparts (BaF3-p185; "cancer cells") as a model for chronic myeloid leukaemia (CML) and Imatinib treated BaF3-p185 cells. The results are compared with reference measurements obtained by a commercial flow cytometry system.

  16. Kinetic discrimination in T-cell activation.

    PubMed Central

    Rabinowitz, J D; Beeson, C; Lyons, D S; Davis, M M; McConnell, H M

    1996-01-01

    We propose a quantitative model for T-cell activation in which the rate of dissociation of ligand from T-cell receptors determines the agonist and antagonist properties of the ligand. The ligands are molecular complexes between antigenic peptides and proteins of the major histocompatibility complex on the surfaces of antigen-presenting cells. Binding of ligand to receptor triggers a series of biochemical reactions in the T cell. If the ligand dissociates after these reactions are complete, the T cell receives a positive activation signal. However, dissociation of ligand after completion of the first reaction but prior to generation of the final products results in partial T-cell activation, which acts to suppress a positive response. Such a negative signal is brought about by T-cell ligands containing the variants of antigenic peptides referred to as T-cell receptor antagonists. Results of recent experiments with altered peptide ligands compare favorably with T-cell responses predicted by this model. PMID:8643643

  17. Mechanosensing Dynamics of Red blood Cells

    NASA Astrophysics Data System (ADS)

    Wan, Jiandi

    2015-11-01

    Mechanical stress-induced deformation of human red blood cells (RBCs) plays important physiopathological roles in oxygen delivery, blood rheology, transfusion, and malaria. Recent studies demonstrate that, in response to mechanical deformation, RBCs release adenosine-5'-triphosphate (ATP), suggesting the existence of mechanotransductive pathways in RBCs. Most importantly, the released ATP from RBCs regulates vascular tone and impaired release of ATP from RBCs has been linked to diseases such as type II diabetes and cystic fibrosis. To date, however, the mechanisms of mechanotransductive release of ATP from RBCs remain unclear. Given that RBCs experience shear stresses continuously during the circulation cycle and the released ATP plays a central role in vascular physiopathology, understanding the mechanotransductive release of ATP from RBCs will provide not only fundamental insights to the role of RBCs in vascular homeostasis but also novel therapeutic strategies for red cell dysfunction and vascular disease. This talk describes the main research in my group on integrating microfluidic-based approaches to study the mechanosensing dynamics of RBCs. Specifically, I will introduce a micro?uidic approach that can probe the dynamics of shear-induced ATP release from RBCs with millisecond resolution and provide quantitative understandings of the mechanosensitive ATP release processes in RBCs. Furthermore, I will also describe our recent findings about the roles of the Piezo1 channel, a newly discovered mechanosensitive cation channel in the mechanotransductive ATP release in RBCs. Last, possible functions of RBCs in the regulation of cerebral blood flow will be discussed.

  18. Red blood cell volume in preterm neonates

    SciTech Connect

    Quaife, M.A.; Dirksen, J.W.; Paxson, C.L. Jr.; McIntire, R.H. Jr.

    1981-10-01

    In the high-risk neonate, the direct determination of the red cell volume by radionuclide dilution technique appears to be the singularly definitive method of defining treatment efficacy, and is thus a useful evaluation and management tool for the pediatrician. For effective patient management, the red blood cell(RBC) volume of 69 preterm and term neonates was determined. The method utilized, Tc-99m-labeled RBCs, provided a fast and accurate answer with a large reduction in the absorbed radiation dose. In the population studied within a high-risk newborn ICU, the mean RBC volumes between the preterm and term neonates were without significant difference. Grouping and analysis of the RBC volume data with respect to birth weight, gestational ages, and 1- and 5-minute Apgar scores revealed on statistical difference. The mean value found in our population, 32.2 +/- 9.2 ml/kg, however, does differ from those previously reported in which the determinations were made using an indirect estimation from the plasma compartment.

  19. Microconfined flow behavior of red blood cells.

    PubMed

    Tomaiuolo, Giovanna; Lanotte, Luca; D'Apolito, Rosa; Cassinese, Antonio; Guido, Stefano

    2016-01-01

    Red blood cells (RBCs) perform essential functions in human body, such as gas exchange between blood and tissues, thanks to their ability to deform and flow in the microvascular network. The high RBC deformability is mainly due to the viscoelastic properties of the cell membrane. Since an impaired RBC deformability could be found in some diseases, such as malaria, sickle cell anemia, diabetes and hereditary disorders, there is the need to provide further insight into measurement of RBC deformability in a physiologically relevant flow field. Here, RBCs deformability has been studied in terms of the minimum apparent plasma-layer thickness by using high-speed video microscopy of RBCs flowing in cylindrical glass capillaries. An in vitro systematic microfluidic investigation of RBCs in micro-confined conditions has been performed, resulting in the determination of the RBCs time recovery constant, RBC volume and surface area and RBC membrane shear elastic modulus and surface viscosity. It has been noticed that the deformability of RBCs induces cells aggregation during flow in microcapillaries, allowing the formation of clusters of cells. Overall, our results provide a novel technique to estimate RBC deformability and also RBCs collective behavior, which can be used for the analysis of pathological RBCs, for which reliable quantitative methods are still lacking. PMID:26071649

  20. Fluorometric assay for red blood cell antibodies

    SciTech Connect

    Schreiber, A.B.; Lambermont, M.; Strosberg, A.D.; Wybran, J.

    1981-03-01

    A fluorometric assay is described for the detection of red blood cell antibodies. The assay reveals as little as 600 molecules of bound, fluoroesceinated rabbit anti-human IgG antibodies per erythrocyte. Eleven patients with possible autoimmune erythrocyte disorder and negative direct antiglobulin test were studied by the fluorometric assay. The outcome of the fluorometric assay was compared with that of the human allogeneic rosette test. Results obtained by the two methods were in complete agreement. Five of the patients were shown to possess unexpectedly high levels of erythrocyte-bound IgG in spite of a negative, direct antiglobulin test. These findings and the validity of the fluorometric assay are discussed.

  1. Optical analysis of red blood cell suspension

    NASA Astrophysics Data System (ADS)

    Szołna, Alicja A.; Grzegorzewski, Bronisław

    2008-12-01

    The optical properties of suspensions of red blood cells (RBCs) were studied. Fresh human venues blood was obtained from adult healthy donors. RBCs were suspended in isotonic salt solution, and in autologous plasma. Suspensions with haematocrit 0.25 - 3% were investigated. Novel technique was proposed to determine the scattering coefficient μs for the suspensions. The intensity of He-Ne laser light transmitted through a wedge-shape container filled with a suspension was recorded. To find the dependence of the intensity on the thickness of the sample the container was moved horizontally. The dependence of μs on the haematocrit was determined for RBCs suspended in the isotonic salt solution. RBCs suspended in plasma tend to form rouleaux. For the RBCs suspended in plasma, the scattering coefficient as a function of time was obtained. It is shown that this technique can be useful in the study of rouleaux formation.

  2. Tissue engineering red blood cells: a therapeutic.

    PubMed

    van Veen, Theun; Hunt, John A

    2015-07-01

    The use of red blood cells (RBCs) in transfusion is widespread in modern medicine. Limitations in blood transfusion have made an urgent argument for the focus on alternatives, as particular medical treatments heavily rely on the supply of donated blood. Stem cells have been successfully used in vitro to produce RBCs and researchers are currently challenged with developing larger-scale culture methods to meet the requirements for clinically relevant cell numbers. The ultimate conditions that will be beneficial for this type of research are trivial. A successful human clinical trial has shown that tremendous progress has already been made in this field. Other alternatives are based on the oxygen carrier protein that RBCs contain, i.e. haemoglobin (Hb). Chemically defined molecules and crosslinked proteins, which are able to bind and transport oxygen, have been found to be functional in vivo. Major progress has been achieved, but developing highly suitable products for the transfusion market still remains an enormous challenge for these acellular blood substitutes. We provide a review about developing alternatives for blood transfusion, with the emphasis on tissue-engineering approaches. PMID:24753354

  3. Growth and replication of red rain cells at 121°C and their red fluorescence

    NASA Astrophysics Data System (ADS)

    Gangappa, Rajkumar; Wickramasinghe, Chandra; Wainwright, Milton; Kumar, A. Santhosh; Louis, Godfrey

    2010-09-01

    We have shown that the red cells found in the Red Rain (which fell on Kerala, India, in 2001) survive and grow after incubation for periods of up to two hours at 121°C . Under these conditions daughter cells appear within the original mother cells and the number of cells in the samples increases with length of exposure to 121°C. No such increase in cells occurs at room temperature, suggesting that the increase in daughter cells is brought about by exposure of the Red Rain cells to high temperatures. This is an independent confirmation of results reported earlier by two of the present authors, claiming that the cells can replicate under high pressure at temperatures upto 300°C. The flourescence behaviour of the red cells is shown to be in remarkable correspondence with the extended red emission observed in the Red Rectagle planetary nebula and other galactic and extragalactic dust clouds, suggesting, though not proving an extraterrestrial origin.

  4. Distribution of chloride permeabilities in normal human red cells.

    PubMed Central

    Raftos, J E; Bookchin, R M; Lew, V L

    1996-01-01

    1. The rate of dehydration of K+ permeabilized red cells is influenced by their Cl- permeability (PCl). In instances of pathological K+ permeabilization, cell-to-cell differences in PCl may determine which red cells dehydrate most. The present study was designed to investigate whether PCl differed significantly among red cells from a single blood sample. 2. Previously available methods measure only the mean PCl of red cell populations. We describe a 'profile migration' method in which dilute red cell suspensions in low-K+ media were permeabilized to K+ with a high concentration of valinomycin, rendering PCl the main rate-limiting factor for cell dehydration. As the cells dehydrated, samples were processed to obtain full haemolysis curves at precise times. Variations in PCl among cells would have appeared as progressive changes in the profile of their haemolysis curves, as the curves migrated towards lower tonicities. 3. Red cells from five normal volunteers showed no change in profile of the migrating haemolysis curves, suggesting that their PCl distributions were fairly uniform. Quantitative analysis demonstrated that intercell variation in PCl was less than 7.5%. 4. Results obtained with this technique were analysed using the Lew-Bookchin red cell model. The calculated PCl was within the normal range described in earlier studies. PMID:8815210

  5. Destruction of newly released red blood cells in space flight

    NASA Technical Reports Server (NTRS)

    Alfrey, C. P.; Udden, M. M.; Huntoon, C. L.; Driscoll, T.

    1996-01-01

    Space flight results in a rapid change in total blood volume, plasma volume, and red blood cell mass because the space to contain blood is decreased. The plasma volume and total blood volume decreases during the first hours in space and remain at a decreased level for the remainder of the flight. During the first several hours following return to earth, plasma volume and total blood volume increase to preflight levels. During the first few days in space recently produced red blood cells disappear from the blood resulting in a decrease in red blood cell mass of 10-15%. Red cells 12 d old or older survive normally and production of new cells continues at near preflight levels. After the first few days in space, the red cell mass is stable at the decreased level. Following return to earth the hemoglobin and red blood cell mass concentrations decrease reflecting the increase in plasma volume. The erythropoietin levels increase responding to "postflight anemia"; red cell production increases, and the red cell mass is restored to preflight levels after several weeks.

  6. Control of red blood cell mass during spaceflight

    NASA Technical Reports Server (NTRS)

    Lane, H. W.; Alfrey, C. P.; Driscoll, T. B.; Smith, S. M.; Nyquist, L. E.

    1996-01-01

    Data are reviewed from twenty-two astronauts from seven space missions in a study of red blood cell mass. The data show that decreased red cell mass in all astronauts exposed to space for more than nine days, although the actual dynamics of mass changes varies with flight duration. Possible mechanisms for these changes, including alterations in erythropoietin levels, are discussed.

  7. Red blood cells in sports: effects of exercise and training on oxygen supply by red blood cells.

    PubMed

    Mairbäurl, Heimo

    2013-01-01

    During exercise the cardiovascular system has to warrant substrate supply to working muscle. The main function of red blood cells in exercise is the transport of O2 from the lungs to the tissues and the delivery of metabolically produced CO2 to the lungs for expiration. Hemoglobin also contributes to the blood's buffering capacity, and ATP and NO release from red blood cells contributes to vasodilation and improved blood flow to working muscle. These functions require adequate amounts of red blood cells in circulation. Trained athletes, particularly in endurance sports, have a decreased hematocrit, which is sometimes called "sports anemia." This is not anemia in a clinical sense, because athletes have in fact an increased total mass of red blood cells and hemoglobin in circulation relative to sedentary individuals. The slight decrease in hematocrit by training is brought about by an increased plasma volume (PV). The mechanisms that increase total red blood cell mass by training are not understood fully. Despite stimulated erythropoiesis, exercise can decrease the red blood cell mass by intravascular hemolysis mainly of senescent red blood cells, which is caused by mechanical rupture when red blood cells pass through capillaries in contracting muscles, and by compression of red cells e.g., in foot soles during running or in hand palms in weightlifters. Together, these adjustments cause a decrease in the average age of the population of circulating red blood cells in trained athletes. These younger red cells are characterized by improved oxygen release and deformability, both of which also improve tissue oxygen supply during exercise. PMID:24273518

  8. Red blood cell vesiculation in hereditary hemolytic anemia

    PubMed Central

    Alaarg, Amr; Schiffelers, Raymond M.; van Solinge, Wouter W.; van Wijk, Richard

    2013-01-01

    Hereditary hemolytic anemia encompasses a heterogeneous group of anemias characterized by decreased red blood cell survival because of inherited membrane, enzyme, or hemoglobin disorders. Affected red blood cells are more fragile, less deformable, and more susceptible to shear stress and oxidative damage, and show increased vesiculation. Red blood cells, as essentially all cells, constitutively release phospholipid extracellular vesicles in vivo and in vitro in a process known as vesiculation. These extracellular vesicles comprise a heterogeneous group of vesicles of different sizes and intracellular origins. They are described in literature as exosomes if they originate from multi-vesicular bodies, or as microvesicles when formed by a one-step budding process directly from the plasma membrane. Extracellular vesicles contain a multitude of bioactive molecules that are implicated in intercellular communication and in different biological and pathophysiological processes. Mature red blood cells release in principle only microvesicles. In hereditary hemolytic anemias, the underlying molecular defect affects and determines red blood cell vesiculation, resulting in shedding microvesicles of different compositions and concentrations. Despite extensive research into red blood cell biochemistry and physiology, little is known about red cell deformability and vesiculation in hereditary hemolytic anemias, and the associated pathophysiological role is incompletely assessed. In this review, we discuss recent progress in understanding extracellular vesicles biology, with focus on red blood cell vesiculation. Also, we review recent scientific findings on the molecular defects of hereditary hemolytic anemias, and their correlation with red blood cell deformability and vesiculation. Integrating bio-analytical findings on abnormalities of red blood cells and their microvesicles will be critical for a better understanding of the pathophysiology of hereditary hemolytic anemias. PMID

  9. Developmental Plasticity of Red Blood Cell Homeostasis

    PubMed Central

    Golub, Mari S.; Hogrefe, Casey E.; Malka, Roy; Higgins, John M.

    2014-01-01

    Most human physiologic set points like body temperature are tightly regulated and show little variation between healthy individuals. Red blood cell (RBC) characteristics such as hematocrit (HCT) and mean cell volume (MCV) are stable within individuals but can vary by 20% from one healthy person to the next. The mechanisms for the majority of this inter-individual variation are unknown and do not appear to involve common genetic variation. Here we show that environmental conditions present during development, namely in utero iron availability, can exert long-term influence on a set point related to the RBC life cycle. In a controlled study of rhesus monkeys and a retrospective study of humans, we use a mathematical model of in vivo RBC population dynamics to show that in utero iron deficiency is associated with a lowered threshold for RBC clearance and turnover. This in utero effect is plastic, persisting at least two years after birth and after the cessation of iron deficiency. Our study reports a rare instance of developmental plasticity in the human hematologic systems and also shows how mathematical modeling can be used to identify cellular mechanisms involved in the adaptive control of homeostatic set points. PMID:24415575

  10. Red blood cell in simple shear flow

    NASA Astrophysics Data System (ADS)

    Chien, Wei; Hew, Yayu; Chen, Yeng-Long

    2013-03-01

    The dynamics of red blood cells (RBC) in blood flow is critical for oxygen transport, and it also influences inflammation (white blood cells), thrombosis (platelets), and circulatory tumor migration. The physical properties of a RBC can be captured by modeling RBC as lipid membrane linked to a cytoskeletal spectrin network that encapsulates cytoplasm rich in hemoglobin, with bi-concave equilibrium shape. Depending on the shear force, RBC elasticity, membrane viscosity, and cytoplasm viscosity, RBC can undergo tumbling, tank-treading, or oscillatory motion. We investigate the dynamic state diagram of RBC in shear and pressure-driven flow using a combined immersed boundary-lattice Boltzmann method with a multi-scale RBC model that accurately captures the experimentally established RBC force-deformation relation. It is found that the tumbling (TU) to tank-treading (TT) transition occurs as shear rate increases for cytoplasm/outer fluid viscosity ratio smaller than 0.67. The TU frequency is found to be half of the TT frequency, in agreement with experiment observations. Larger viscosity ratios lead to the disappearance of stable TT phase and unstable complex dynamics, including the oscillation of the symmetry axis of the bi-concave shape perpendicular to the flow direction. The dependence on RBC bending rigidity, shear modulus, the order of membrane spectrin network and fluid field in the unstable region will also be discussed.

  11. Altered red and white blood cell rheology in type II diabetes.

    PubMed

    Ernst, E; Matrai, A

    1986-12-01

    Twenty-three patients suffering from type II, non-insulin-dependent diabetes were compared with matched controls. Suspensions with standardized white and red cell counts were filtered in a novel device capable of discriminating filter occlusion and cell transit time. Results confirm previous studies indicating that red cell deformability is impaired in diabetes. According to our findings, this may be caused by a slight overall loss of red cell fluidity together with the existence of a subpopulation of more markedly rigid erythrocytes. Furthermore, we demonstrate that white cell filterability is reduced in type II diabetes. This could be due to decreased white cell deformability, increased white cell adhesion, or both. Analysis of diabetic subgroups indicates that the white cell rheology is impaired to a greater extent in patients taking oral antidiabetic drugs than in patients controlled by diet alone. Altered white cell rheology could help to explain the pathological blood cell filterability frequently reported in diabetes. More important, impaired white cell rheology might significantly contribute to microcirculatory flow abnormalities jeopardizing O2 exchange in the terminal vascular bed. PMID:3770316

  12. Mechanical properties of stored red blood cells using optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, Adriana; Alexandre de Thomaz, Andre; de Ysasa Pozzo, Liliana; de Lourdes Barjas-Castro, Maria; Brandao, Marcelo M.; Saad, Sara T. O.; Barbosa, Luiz Carlos; Cesar, Carlos Lenz

    2005-08-01

    We have developed a method for measuring the red blood cell (RBC) membrane overall elasticity μ by measuring the deformation of the cells when dragged at a constant velocity through a plasma fluid by an optical tweezers. The deformability of erythrocytes is a critical determinant of blood flow in the microcirculation. We tested our method and hydrodynamic models, which included the presence of two walls, by measuring the RBC deformation as a function of drag velocity and of the distance to the walls. The capability and sensitivity of this method can be evaluated by its application to a variety of studies, such as, the measurement of RBC elasticity of sickle cell anemia patients comparing homozygous (HbSS), including patients taking hydroxyrea (HU) and heterozygous (HbAS) with normal donors and the RBC elasticity measurement of gamma irradiated stored blood for transfusion to immunosupressed patients as a function of time and dose. These studies show that the technique has the sensitivity to discriminate heterozygous and homozygous sickle cell anemia patients from normal donors and even follow the course of HU treatment of Homozygous patients. The gamma irradiation studies show that there is no significant change in RBC elasticity over time for up to 14 days of storage, regardless of whether the unit was irradiated or not, but there was a huge change in the measured elasticity for the RBC units stored for more than 21 days after irradiation. These finds are important for the assessment of stored irradiated RBC viability for transfusion purposes because the present protocol consider 28 storage days after irradiation as the limit for the RBC usage.

  13. Red Blood Cells Preconditioned with Hemin Are Less Permissive to Plasmodium Invasion In Vivo and In Vitro

    PubMed Central

    Gaudreault, Véronique; Wirbel, Jakob; Jardim, Armando; Rohrbach, Petra; Scorza, Tatiana

    2015-01-01

    Malaria is a parasitic disease that causes severe hemolytic anemia in Plasmodium-infected hosts, which results in the release and accumulation of oxidized heme (hemin). Although hemin impairs the establishment of Plasmodium immunity in vitro and in vivo, mice preconditioned with hemin develop lower parasitemia when challenged with Plasmodium chabaudi adami blood stage parasites. In order to understand the mechanism accounting for this resistance as well as the impact of hemin on eryptosis and plasma levels of scavenging hemopexin, red blood cells were labeled with biotin prior to hemin treatment and P. c. adami infection. This strategy allowed discriminating hemin-treated from de novo generated red blood cells and to follow the infection within these two populations of cells. Fluorescence microscopy analysis of biotinylated-red blood cells revealed increased P. c. adami red blood cells selectivity and a decreased permissibility of hemin-conditioned red blood cells for parasite invasion. These effects were also apparent in in vitro P. falciparum cultures using hemin-preconditioned human red blood cells. Interestingly, hemin did not alter the turnover of red blood cells nor their replenishment during in vivo infection. Our results assign a function for hemin as a protective agent against high parasitemia, and suggest that the hemolytic nature of blood stage human malaria may be beneficial for the infected host. PMID:26465787

  14. Light scattering by aggregated red blood cells.

    PubMed

    Tsinopoulos, Stephanos V; Sellountos, Euripides J; Polyzos, Demosthenes

    2002-03-01

    In low flow rates, red blood cells (RBCs) fasten together along their axis of symmetry and form a so-called rouleaux. The scattering of He-Ne laser light by a rouleau consisting of n (2 < or = n < or = 8) average-sized RBCs is investigated. The interaction problem is treated numerically by means of an advanced axisymmetric boundary element--fast Fourier transform methodology. The scattering problem of one RBC was solved first, and the results showed that the influence of the RBC's membrane on the scattering patterns is negligible. Thus the rouleau is modeled as an axisymmetric, homogeneous, low-contrast dielectric cylinder, on the surface of which appears, owing to aggregated RBCs, a periodic roughness along the direction of symmetry. The direction of the incident laser light is considered to be perpendicular to the scatterer's axis of symmetry. The differential scattering cross sections in both perpendicular and parallel scattering planes and for all the scattering angles are calculated and presented in detail. PMID:11900021

  15. Light scattering by aggregated red blood cells

    NASA Astrophysics Data System (ADS)

    Tsinopoulos, Stephanos V.; Sellountos, Euripides J.; Polyzos, Demosthenes

    2002-03-01

    In low flow rates, red blood cells (RBCs) fasten together along their axis of symmetry and form a so-called rouleaux. The scattering of He-Ne laser light by a rouleau consisting of n (2 less-than-or-equal n less-than-or-equal 8) average-sized RBCs is investigated. The interaction problem is treated numerically by means of an advanced axisymmetric boundary element--fast Fourier transform methodology. The scattering problem of one RBC was solved first, and the results showed that the influence of the RBC's membrane on the scattering patterns is negligible. Thus the rouleau is modeled as an axisymmetric, homogeneous, low-contrast dielectric cylinder, on the surface of which appears, owing to aggregated RBCs, a periodic roughness along the direction of symmetry. The direction of the incident laser light is considered to be perpendicular to the scatterer's axis of symmetry. The differential scattering cross sections in both perpendicular and parallel scattering planes and for all the scattering angles are calculated and presented in detail.

  16. Electrochemical Red Blood Cell Counting: One at a Time.

    PubMed

    Sepunaru, Lior; Sokolov, Stanislav V; Holter, Jennifer; Young, Neil P; Compton, Richard G

    2016-08-01

    We demonstrate that the concentration of a red blood cell solution under physiological conditions can be determined by electrochemical voltammetry. The magnitude of the oxygen reduction currents produced at an edge-plane pyrolytic graphite electrode was diagnosed analytically at concentrations suitable for a point-of-care test device. The currents could be further enhanced when the solution of red blood cells was exposed to hydrogen peroxide. We show that the enhanced signal can be used to detect red blood cells at a single entity level. The method presented relies on the catalytic activity of red blood cells towards hydrogen peroxide and on surface-induced haemolysis. Each single cell activity is expressed as current spikes decaying within a few seconds back to the background current. The frequency of such current spikes is proportional to the concentration of cells in solution. PMID:27355839

  17. Discrimination of the toxic potential of chemically differing topical glucocorticoids using a neutral red release assay with human keratinocytes and fibroblasts.

    PubMed

    Korting, H C; Hülsebus, E; Kerscher, M; Greber, R; Schäfer-Korting, M

    1995-07-01

    In inflammatory skin disease, hydrocortisone and prednisolone double esters are about equipotent to conventional medium potency topical glucocorticoids, such as betamethasone valerate. Local adverse effects, in particular skin atrophy, are a potential problem with topical glucocorticoids. Recently, cell cultures have shown promise as a means of assessing local tolerance. To investigate the toxic potential of hydrocortisone, hydrocortisone-17-butyrate, hydrocortisone aceponate, prednicarbate, triamcinolone acetonide, betamethasone valerate and desoximethasone, human keratinocytes and fibroblasts were exposed to these agents in vitro, using a modified neutral red release assay. In addition, the morphology of these cells was assessed by light microscopy. Although all the topical glucocorticoids tested proved toxic to both cell types, there were major differences between glucocorticoids in their effect on fibroblasts. Hydrocortisone and the non-halogenated double-ester-type glucocorticoids were less toxic than the conventional medium potency topical glucocorticoids tested (betamethasone valerate and desoximethasone). In particular, hydrocortisone aceponate was less toxic than betamethasone valerate (P < or = 0.05). In general, the effect of topical glucocorticoids on the cells, based on neutral red release, was more marked with keratinocytes than with fibroblasts. Although the ranking order with respect to the toxic potential was similar, a clear-cut difference was not observed between non-halogenated double-ester-type glucocorticoids and betamethasone valerate. Morphological changes due to glucocorticoid exposure followed the same pattern with both keratinocytes and fibroblasts. The neutral red release assay is able to discriminate between the cytotoxic effects of chemically differing topical glucocorticoids on human keratinocytes and fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7669640

  18. Effects of helicopter transport on red blood cell components

    PubMed Central

    Otani, Taiichi; Oki, Ken-ichi; Akino, Mitsuaki; Tamura, Satoru; Naito, Yuki; Homma, Chihiro; Ikeda, Hisami; Sumita, Shinzou

    2012-01-01

    Background There are no reported studies on whether a helicopter flight affects the quality and shelf-life of red blood cells stored in mannitol-adenine-phosphate. Materials and methods Seven days after donation, five aliquots of red blood cells from five donors were packed into an SS-BOX-110 container which can maintain the temperature inside the container between 2 °C and 6 °C with two frozen coolants. The temperature of an included dummy blood bag was monitored. After the box had been transported in a helicopter for 4 hours, the red blood cells were stored again and their quality evaluated at day 7 (just after the flight), 14, 21 and 42 after donation. Red blood cell quality was evaluated by measuring adenosine triphosphate, 2,3-diphosphoglycerate, and supernatant potassium, as well as haematocrit, intracellular pH, glucose, supernatant haemoglobin, and haemolysis rate at the various time points. Results During the experiment the recorded temperature remained between 2 and 6 °C. All data from the red blood cells that had undergone helicopter transportation were the same as those from a control group of red blood cell samples 7 (just after the flight), 14, 21, and 42 days after the donation. Only supernatant Hb and haemolysis rate 42 days after the donation were slightly increased in the helicopter-transported group of red blood cell samples. All other parameters at 42 days after donation were the same in the two groups of red blood cells. Discussion These results suggest that red blood cells stored in mannitol-adenine-phosphate are not significantly affected by helicopter transportation. The differences in haemolysis by the end of storage were small and probably not of clinical significance. PMID:22153688

  19. Dielectrophoretic discrimination of cancer cells on a microchip

    NASA Astrophysics Data System (ADS)

    Huang, Chengjun; Liu, Chengxun; Minne, Bart; Ramirez Hernandez, Juan Enrique; Stakenborg, Tim; Lagae, Liesbet

    2014-10-01

    The analysis of single cell type typically requires expensive equipments in combination with labeling techniques. As a label-free alternative, in this letter, the characteristic dielectric properties of various cancer cell lines (MCF-7, SKOV-3, MDA-MB-231, and LnCap) and healthy peripheral blood mononuclear cells were examined and compared using the dielectrophoretic (DEP) crossover frequency technique. We found that each type of the cancer cells shows a distinct DEP crossover frequency with an order of SKOV-3, MDA-MB-231, MCF-7, and LnCap from low to high frequency, from which the specific cell membrane capacitance and membrane conductance could be derived. Cell fixation and antibody coupling were found to have minimal or no effects on the cell dielectric properties while cell permeabilization significantly changed the DEP crossover frequency. These findings suggested that the DEP crossover frequency is promising to be used as a "dielectric finger print" to discriminate different cell types and may even enable the specific manipulation of certain cell types, for example, to isolate cancer cells from blood.

  20. Discriminating dengue-infected hepatic cells (WRL-68) using dielectrophoresis.

    PubMed

    Yafouz, Bashar; Kadri, Nahrizul Adib; Rothan, Hussin A; Yusof, Rohana; Ibrahim, Fatimah

    2016-02-01

    Dielectrophoresis (DEP), the induced movement of dielectric particles placed in a nonuniform electric field, has been used as a potential technique for manipulation and separation of many biological samples without destructive consequences to the cell. Cells of the same genotype in different physiological and pathological states have unique morphological and structural features, therefore, it is possible to differentiate between them using their DEP responses. This paper reports the experimental discrimination of normal and dengue-infected human hepatic fetal epithelial cells (WRL-68 cells) based on their DEP crossover frequency, at which no resultant movement occurs in the cells in response to the DEP force. A microarray dot electrode was used to conduct the DEP experiments. The DEP forces applied to the cells were quantified by analyzing the light intensity shift within the electrode's dot region based on the Cumulative Modal Intensity Shift image analysis technique. The differences in dielectric properties between infected and uninfected cells were exploited by plotting a unique DEP spectrum for each set of cells. We observed that the crossover frequency decreased from 220 kHz for the normal WRL-68 cells to 140 kHz after infection with the dengue virus in a medium conductivity of 100 μS/cm. We conclude that the change in the DEP crossover frequency between dengue-infected cells and their healthy counterparts should allow direct characterization of these cell types by exploiting their electrophysiological properties. PMID:26530354

  1. Dysferlin and Other Non-Red Cell Proteins Accumulate in the Red Cell Membrane of Diamond-Blackfan Anemia Patients

    PubMed Central

    Pesciotta, Esther N.; Sriswasdi, Sira; Tang, Hsin-Yao; Speicher, David W.; Mason, Philip J.; Bessler, Monica

    2014-01-01

    Diamond Blackfan Anemia (DBA) is a congenital anemia usually caused by diverse mutations in ribosomal proteins. Although the genetics of DBA are well characterized, the mechanisms that lead to macrocytic anemia remain unclear. We systematically analyzed the proteomes of red blood cell membranes from multiple DBA patients to determine whether abnormalities in protein translation or erythropoiesis contribute to the observed macrocytosis or alterations in the mature red blood cell membrane. In depth proteome analysis of red cell membranes enabled highly reproducible identification and quantitative comparisons of 1100 or more proteins. These comparisons revealed clear differences between red cell membrane proteomes in DBA patients and healthy controls that were consistent across DBA patients with different ribosomal gene mutations. Proteins exhibiting changes in abundance included those known to be increased in DBA such as fetal hemoglobin and a number of proteins not normally found in mature red cell membranes, including proteins involved in the major histocompatibility complex class I pathway. Most striking was the presence of dysferlin in the red blood cell membranes of DBA patients but absent in healthy controls. Immunoblot validation using red cell membranes isolated from additional DBA patients and healthy controls confirmed a distinct membrane protein signature specific to patients with DBA. PMID:24454878

  2. Molecular basis of red cell membrane disorders.

    PubMed

    Delaunay, Jean

    2002-01-01

    We will consider an array of genetic disorders of the red cell membrane. Some affect well-known genes. The mutations of most cases of hereditary spherocytosis (HS) are located in the following genes: ANK1, SPTB, SLC4A1, EPB42 and SPTA1, which encode ankyrin, spectrin beta-chain, the anion exchanger 1 (band 3), protein 4.2 and spectrin alpha-chain, respectively. A dominant form of distal renal tubular acidosis also stems from distinct mutations in the SLC4A1 gene. The mutations responsible for hereditary elliptocytosis (HE) and its aggravated form, poikilocytosis (HP), lie in the SPTA1 and SPTB gene, already mentioned, and in the EPB41 gene encoding protein 4.1. Whereas in HS, the SPTA1 and SPTB gene mutations tend to abolish the synthesis of the corresponding chains, in HE/HP, they hinder spectrin tetramerization. Allele alpha(LELY) is a common polymorphic allele which plays the role of an aggravating factor when it occurs in trans of an elliptocytogenic allele of the SPTA1 gene. Southeast Asian ovalocytosis results from a 27- nucleotide deletion in the SLC4A1 gene. Besides these conditions in which the mutations were reached from known alterations in the proteins, other conditions required a positional cloning approach. Such are the genetic disorders of membrane permeability to monovalent cations. Knowledge is the most advanced as regards dehydrated hereditary stomatocytois (DHS). DHS was shown to belong to a pleiotropic syndrome: DHS + fetal edema + pseudohyperkalemia, which maps to 16q23-24. Concerning DHS and another disease of the same class, overhydrated hereditary stomatocytosis, splenectomy almost certainly appears to elicit thromboembolic accidents. PMID:12432217

  3. Single-cell measurement of red blood cell oxygen affinity

    PubMed Central

    Di Caprio, Giuseppe; Stokes, Chris; Higgins, John M.; Schonbrun, Ethan

    2015-01-01

    Oxygen is transported throughout the body by hemoglobin (Hb) in red blood cells (RBCs). Although the oxygen affinity of blood is well-understood and routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of RBC volume and Hb concentration are taken millions of times per day by clinical hematology analyzers, and they are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume, and Hb concentration for individual RBCs in high throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.9%, which corresponds to the maximum slope of the oxygen–Hb dissociation curve. In addition, single-cell oxygen affinity is positively correlated with Hb concentration but independent of osmolarity, which suggests variation in the Hb to 2,3-diphosphoglycerate (2–3 DPG) ratio on a cellular level. By quantifying the functional behavior of a cellular population, our system adds a dimension to blood cell analysis and other measurements of single-cell variability. PMID:26216973

  4. Models for the red blood cell lifespan.

    PubMed

    Shrestha, Rajiv P; Horowitz, Joseph; Hollot, Christopher V; Germain, Michael J; Widness, John A; Mock, Donald M; Veng-Pedersen, Peter; Chait, Yossi

    2016-06-01

    The lifespan of red blood cells (RBCs) plays an important role in the study and interpretation of various clinical conditions. Yet, confusion about the meanings of fundamental terms related to cell survival and their quantification still exists in the literature. To address these issues, we started from a compartmental model of RBC populations based on an arbitrary full lifespan distribution, carefully defined the residual lifespan, current age, and excess lifespan of the RBC population, and then derived the distributions of these parameters. For a set of residual survival data from biotin-labeled RBCs, we fit models based on Weibull, gamma, and lognormal distributions, using nonlinear mixed effects modeling and parametric bootstrapping. From the estimated Weibull, gamma, and lognormal parameters we computed the respective population mean full lifespans (95 % confidence interval): 115.60 (109.17-121.66), 116.71 (110.81-122.51), and 116.79 (111.23-122.75) days together with the standard deviations of the full lifespans: 24.77 (20.82-28.81), 24.30 (20.53-28.33), and 24.19 (20.43-27.73). We then estimated the 95th percentiles of the lifespan distributions (a surrogate for the maximum lifespan): 153.95 (150.02-158.36), 159.51 (155.09-164.00), and 160.40 (156.00-165.58) days, the mean current ages (or the mean residual lifespans): 60.45 (58.18-62.85), 60.82 (58.77-63.33), and 57.26 (54.33-60.61) days, and the residual half-lives: 57.97 (54.96-60.90), 58.36 (55.45-61.26), and 58.40 (55.62-61.37) days, for the Weibull, gamma, and lognormal models respectively. Corresponding estimates were obtained for the individual subjects. The three models provide equally excellent goodness-of-fit, reliable estimation, and physiologically plausible values of the directly interpretable RBC survival parameters. PMID:27039311

  5. Formation of dimethylthioarsenicals in red blood cells

    SciTech Connect

    Naranmandura, Hua; Suzuki, Kazuo T.

    2008-03-15

    The bladder and skin are the primary targets for arsenic-induced carcinogenicity in mammals. Thioarsenicals dimethylmonothioarsinic (DMMTA{sup V}) and dimethyldithioarsinic (DMDTA{sup V}) acids are common urinary metabolites, the former being much more toxic than non-thiolated dimethylarsinic acid (DMA{sup V}) and comparable to dimethylarsinous acid (DMA{sup III}) in epidermoid cells, suggesting that the metabolic production of thioarsenicals may be a risk factor for the development of cancer in these organs. To reveal their production sites (tissues/body fluids), we examined the uptake and transformation of the four dimethylated arsenicals by incubation with rat and human red blood cells (RBCs). Although DMA{sup V} and DMDTA{sup V} were not taken up by either type of RBCs, DMA{sup III} and DMMTA{sup V} were taken up by both (more efficiently by rat ones), though DMMTA{sup V} was taken up slowly, and then the arsenic transformed into DMDTA{sup V} was excreted from both types of animal RBCs. On the other hand, although DMA{sup III} taken up rapidly by rat RBCs was retained in the RBCs, that taken up by human RBCs was immediately transformed into DMMTA{sup V} and then excreted into the incubation medium without being retained in the RBCs. In a separate experiment, arsenic remaining in primary rat hepatocytes after incubation with 1.5 {mu}M DMA{sup III} was recovered from the incubation medium in the forms of DMA{sup V} and DMMTA{sup V} in the presence of human RBCs, but not in the presence of rat RBCs (in which the arsenic was bound to hemoglobin). Thus, DMMTA{sup V} was detected in the medium only in the presence of human RBCs and increased with incubation time. It was proposed that arsenic is excreted from hepatocytes into the bloodstream in the form of DMA{sup III} and then taken up by RBCs in humans, where it is transformed into DMMTA{sup V} and then excreted again into the bloodstream.

  6. Reflectance confocal microscopy of red blood cells: simulation and experiment

    PubMed Central

    Zeidan, Adel; Yelin, Dvir

    2015-01-01

    Measuring the morphology of red blood cells is important for clinical diagnosis, providing valuable indications on a patient’s health. In this work, we have simulated the appearance of normal red blood cells under a reflectance confocal microscope and discovered unique relations between the morphological parameters and the resulting characteristic interference patterns of the cell. The simulation results showed good agreement with in vitro reflectance confocal images of red blood cells, acquired using spectrally encoded flow cytometry that imaged the cells in a linear flow without artificial staining. By matching the simulated patterns to confocal images of the cells, this method could be used for measuring cell morphology in three dimensions and for studying their physiology. PMID:26600999

  7. A scanning acoustic microscope discriminates cancer cells in fluid

    NASA Astrophysics Data System (ADS)

    Miura, Katsutoshi; Yamamoto, Seiji

    2015-10-01

    Scanning acoustic microscopy (SAM) discriminates lesions in sections by assessing the speed of sound (SOS) or attenuation of sound (AOS) through tissues within a few minutes without staining; however, its clinical use in cytological diagnosis is unknown. We applied a thin layer preparation method to observe benign and malignant effusions using SAM. Although SAM is inferior in detecting nuclear features than light microscopy, it can differentiate malignant from benign cells using the higher SOS and AOS values and large irregular cell clusters that are typical features of carcinomas. Moreover, each single malignant cell exhibits characteristic cytoplasmic features such as a large size, irregular borders and secretory or cytoskeletal content. By adjusting the observation range, malignant cells are differentiated from benign cells easily using SAM. Subtle changes in the functional and structural heterogeneity of tumour cells were pursuable with a different digital data of SAM. SAM can be a useful tool for screening malignant cells in effusions before light microscopic observation. Higher AOS values in malignant cells compared with those of benign cells support the feasibility of a novel sonodynamic therapy for malignant effusions.

  8. Red blood cell-derived microparticles: An overview.

    PubMed

    Westerman, Maxwell; Porter, John B

    2016-07-01

    The red blood cell (RBC) is historically the original parent cell of microparticles (MPs). In this overview, we describe the discovery and the early history of red cell-derived microparticles (RMPs) and present an overview of the evolution of RMP. We report the formation, characteristics, effects of RMP and factors which may affect RMP evaluation. The review examines RMP derived from both normal and pathologic RBC. The pathologic RBC studies include sickle cell anemia (SCA), sickle cell trait (STr), thalassemia intermedia (TI), hereditary spherocytosis (HS), hereditary elliptocytosis (HE), hereditary stomatocytosis (HSt) and glucose-6-phosphate dehydrogenase deficiency (G6PD). PMID:27282583

  9. Method for determining properties of red blood cells

    DOEpatents

    Gourley, Paul L.

    2001-01-01

    A method for quantifying the concentration of hemoglobin in a cell, and indicia of anemia, comprises determining the wavelength of the longitudinal mode of a liquid in a laser microcavity; determining the wavelength of the fundamental transverse mode of a red blood cell in the liquid in the laser microcavity; and determining if the cell is anemic from the difference between the wavelength of the longitudinal mode and the fundamental transverse mode. In addition to measuring hemoglobin, the invention includes a method using intracavity laser spectroscopy to measure the change in spectra as a function of time for measuring the influx of water into a red blood cell and the cell's subsequent rupture.

  10. The Effect of Shape Memory on Red Blood Cell Motions

    NASA Astrophysics Data System (ADS)

    Niu, Xiting; Shi, Lingling; Pan, Tsorng-Whay; Glowinski, Roland

    2013-11-01

    An elastic spring model is applied to study the effect of the shape memory on the motion of red blood cell in flows. In shear flow, shape memory also plays an important role to obtain all three motions: tumbling, swinging, and tank-treading. In Poiseuille flow, cell has an equilibrium shape as a slipper or parachute depending on capillary number. To ensure the tank-treading motion while in slippery shape, a modified model is proposed by introducing a shape memory coefficient which describes the degree of shape memory in cells. The effect of the coefficient on the cell motion of red blood cell will be presented.

  11. Chloride transport in human red cells.

    PubMed Central

    Dalmark, M

    1975-01-01

    1. The chloride equilibrium flux (chloride self-exchange) was determined by measuring the rate of 36Cl efflux from radioactively labelled human red cells. The cellular chloride concentration was varied between 5 and 700 mM by the nystatin technique (Cass & Dalmark, 1973). The chloride transport capacity was not affected by the nystatin technique. 2. The chloride equilibrium flux showed saturation kinetics in the pH range between 6-2 and 9-2 (0 degrees C). The chloride transport decreased at chloride concentrations higher than those which gave the maximum transport. 3. The apparent half-saturation constant, (K1/2), depended on the pH and whether the chloride transport was perceived as a function of the chloride concentration in the medium or in the cell water. The (K1/2)m increased and the (K1/2)c decreased with increasing pH. The dependence of the chloride transport on the chloride concentration was described by Michaelis-Menten kinetics at pH 7-2, but at values of pH outside pH 7-8 S-shaped or steeper graphs were observed. 4. The chloride equilibrium flux varied with the pH at constant chloride concentration in the medium (pH 5-7-9-5). The transport had a bell-shaped pH dependence at chloride concentrations below 200 mM. At chloride concentrations between 300 and 600 mM the chloride transport increased with increasing pH to reach a plateau around pH 8. The position of the acidic branches of the pH graphs was independent of the chloride concentration (25-600 mM), but the position of the alkaline branches moved towards higher values of pH with increasing chloride concentration (5-150 mM). Thus, the position of the pH optimum increased with increasing chloride concentration. The chloride transport at low pH values was a function of the inverse second power of the hydrogen ion concentration. The pK of the groups which caused the inhibition was approximately 6 and independent of the temperature (0-18 degrees C). 5. The chloride equilibrium flux as a function of

  12. Shades of red: bird-pollinated flowers target the specific colour discrimination abilities of avian vision.

    PubMed

    Shrestha, Mani; Dyer, Adrian G; Boyd-Gerny, Skye; Wong, Bob B M; Burd, Martin

    2013-04-01

    Colour signals are a major cue in putative pollination syndromes. There is evidence that the reflectance spectra of many flowers target the distinctive visual discrimination abilities of hymenopteran insects, but far less is known about bird-pollinated flowers. Birds are hypothesized to exert different selective pressures on floral colour compared with hymenopterans because of differences in their visual systems. We measured the floral reflectance spectra of 206 Australian angiosperm species whose floral visitors are known from direct observation rather than inferred from floral characteristics. We quantified the match between these spectra and the hue discrimination abilities of hymenopteran and avian vision, and analysed these metrics in a phylogenetically informed comparison of flowers in different pollination groups. We show that bird-visited flowers and insect-visited flowers differ significantly from each other in the chromatic cues they provide, and that the differences are concentrated near wavelengths of optimal colour discrimination by whichever class of pollinator visits the flowers. Our results indicate that angiosperms have evolved the spectral signals most likely to reinforce their pollinators' floral constancy (the tendency of individual pollinators to visit flowers of the same species) in communities of similarly coloured floral competitors. PMID:23368754

  13. In vivo red blood cell compatibility testing using indium-113m tropolone-labeled red blood cells

    SciTech Connect

    Morrissey, G.J.; Gravelle, D.; Dietz, G.; Driedger, A.A.; King, M.; Cradduck, T.D.

    1988-05-01

    In vivo radionuclide crossmatch is a method for identifying compatible blood for transfusion when allo- or autoantibodies preclude the use of conventional crossmatching techniques. A technique for labeling small volumes of donor red blood cells with (/sup 113m/In)tropolone is reported. The use of /sup 113m/In minimizes the accumulation of background radioactivity and the radiation dose especially so when multiple crossmatches are performed. Labeling red cells with (/sup 113m/In)tropolone is faster and easier to perform than with other radionuclides. Consistently high labeling efficiencies are obtained and minimal /sup 113m/In activity elutes from the labeled red blood cells. A case study involving 22 crossmatches is presented to demonstrate the technique. The radiation dose equivalent from /sup 113m/In is significantly less than with other radionuclides that may be used to label red cells.

  14. Separation of a single cell by red-laser manipulation

    NASA Astrophysics Data System (ADS)

    Shikano, Shuji; Horio, Koji; Ohtsuka, Yoshihiro; Eto, Yuzuro

    1999-10-01

    A single cell of yeast was separated from a bulk sample of yeast without causing damage to the cell. A focused red-laser light beam was used for trapping and transporting the cell. A specially designed microchannel separator played an essential role in the success of the separation.

  15. Acetylcholinesterase: an enzymatic marker of human red blood cell aging.

    PubMed

    Prall, Y G; Gambhir, K K; Ampy, F R

    1998-01-01

    The purpose of this investigation was to determine whether acetylcholinesterase (AChE) can be used as a marker of cell aging in human red blood cells (RBCs). This study used consented subjects; both males and females in an age range of 21-42 years. The blood samples (8-9 mL) were drawn in tubes containing sodium heparin or EDTA as anticoagulants. To avoid contamination with other cells, (lymphocytes, monocytes and reticulocytes), RBCs were purified (PRBC) by Hypaque-Ficoll gradient technique. The PRBCs were subfractionated into young (y) (1.08-1.09), mid (m) (1.09-1.11) and old (o) (1.11-1.12) percoll density (g/mL) fractions using a discontinuous percoll gradient. The mean +/- 1 SD AChE per gram hemoglobin (U/g Hgb) activities in whole blood (WB) purified human red blood cells (PRBCs), young human red blood cells (y-RBCs), mid age human red blood cells (m-RBCs) and old human red blood cells (o-RBCs) were 27.4 +/- 2.98, 26.0 +/- 2.33, 25.5 +/- 1.64, 20.3 +/- 3.84, 14.6 +/- 3.42 in males and 26.3 +/- 4.44, 24.8 /- 4.83, 26.4 +/- 4.59, 24.0 +/- 5.50 and 12.4 +/- 7.09 in females respectively. Although there was variation in the data, the results indicated that old human red blood cells showed significantly (p<.05) lower AChE activity compared to young human red blood cells of both sexes. These preliminary but novel observations suggest that AChE can be an excellent enzymatic marker for RBC aging in man. PMID:9698047

  16. Transplantation of Adrenal Cortical Progenitor Cells Enriched by Nile Red

    PubMed Central

    Dunn, James C.Y.; Chu, Yinting; Qin, Harry H.; Zupekan, Tatiana

    2009-01-01

    Background The adrenal cortex may contain progenitor cells useful for tissue regeneration. Currently there are no established methods to isolate these cells. Material and Methods Murine adrenal cells were sorted into a Nile-Red-bright (NRbright) and a Nile-Red-dim (NRdim) population of cells according to their degree of cholesterol content revealed by Nile Red fluorescence. The cells were transplanted under the renal capsule to determine their ability for regeneration. Results The NRbright cells contained an abundance of lipid droplets, whereas the NRdim cells contained little. The NRbright cells expressed Sf1 and the more differentiated adrenal cortical genes including Cyp11a1, Cyp11b1, and Cyp11b2, whereas the NRdim cells expressed Sf1 but not the more differentiated adrenal cortical genes. After 56 days of implantation in unilateral adrenalectomized mice, the NRdim cells expressed Sf1 and the more differentiated adrenal cortical genes, whereas the NRbright cells ceased to express Sf1 as well as the more differentiated adrenal cortical genes. NRdim cells also proliferated in the presence of basic fibroblast growth factor. Conclusions The population of NRdim cells contained adrenal cortical progenitor cells that can proliferate and give rise to differentiated daughter cells. These cells may be useful for adrenal cortical regeneration. PMID:19592014

  17. Pure red-cell aplasia "epidemic"--mystery completely revealed?

    PubMed

    Locatelli, Francesco; Del Vecchio, Lucia; Pozzoni, Pietro

    2007-06-01

    Starting in 1998, the number of pure red-cell aplasia (PRCA) cases in patients treated with recombinant human erythropoietin (rHuEPO) increased dramatically. Most cases were observed in patients treated with epoetin alfa produced outside the United States. The peak was observed in 2002; since then, the PRCA incidence has declined. Many factors are likely to have contributed to this up-surge. The molecular structure of the various epoetins and patient characteristics do not seem to play a major role. The route of administration holds some importance, because most PRCA patients received rHuEPO subcutaneously. The peak of PRCA cases overlapped with the removal of human serum albumin from the Eprex formulation (Janssen-Pharmaceutica NV, Beerse, Belgium), for which polysorbate 80 and glycine were substituted. Polysorbate 80 may have increased the immunogenicity of Eprex by eliciting the formation of epoetin-containing micelles or by interacting with leachates released by the uncoated rubber stoppers of prefilled syringes. Compared with the previous formulation, the polysorbate 80 formulation has lower stability, making it more susceptible to stress conditions such as insufficient attention to the cold chain. This situation could facilitate protein denaturation or aggregate formation. Uncoated rubber stoppers were replaced with coated stoppers, and the cold chain was reinforced; the Eprex formulation has remained unchanged. Even though the incidence of PRCA returned to very low levels, discriminating the cause-effect relationship of a single action is difficult, given that all occurred with a similar chronology, and that PRCA develops after a relatively long exposure period. Careful observation of future trends of new PRCA cases is thus mandatory. PMID:17556324

  18. Theory of the sphering of red blood cells.

    PubMed

    Fung, Y C; Tong, P

    1968-02-01

    A rigorous mathematical solution of the sphering of a red blood cell is obtained under the assumptions that the red cells is a fluid-filled shell and that it can swell into a perfect sphere in an appropriate hypotonic medium. The solution is valid for finite strain of the cell membrane provided that the membrane is isotropic, elastic and incompressible. The most general nonlinear elastic stress-strain law for the membrane in a state of generalized plane stress is used. A necessary condition for a red cell to be able to sphere is that its extensional stiffness follow a specific distribution over the membrane. This distribution is strongly influenced by the surface tension in the cell membrane. A unique relation exists between the extensional stiffness, pressure differential, surface tension, and the ratio of the radius of the sphere to that of the undeformed red cell. The functional dependence of this stiffness distribution on various physical parameters is presented. A critique of some current literature on red cell mechanics is presented. PMID:5639934

  19. Rheology of dilute suspensions of red blood cells: experimental and theoretical approaches

    NASA Astrophysics Data System (ADS)

    Drochon, A.

    2003-05-01

    Shear viscosity measurements with dilute suspensions of red blood cells are interpreted using a microrheological model that relates the bulk measurements to the physical properties of the suspended cells. It is thus possible to quantify the average deformability of a RBC population in terms of a mean value of the membrane shear elastic modulus E_s. The values obtained for normal cells are in good agreement with those given in the literature. The method allows to discriminate between normal and altered (diamide or glutaraldehyde treated) cells or pathological cells (scleroderma). The predictions of the microrheological model, based on analytic calculations, are also compared with the numerical results of Ramanujan and Pozrikidis (JFM 361, 1998) for dilute suspensions of capsules in simple shear flow.

  20. Radiolabeled red blood cells: status, problems, and prospects

    SciTech Connect

    Srivastava, S.C.

    1983-01-01

    Radionuclidic labels for red cells can be divided into two main categories - cohort or pulse labels, and random labels. The random labels are incorporated into circulating cells of all ages and the labeling process is usually carried out in vitro. The red cell labels in predominant use involve random labeling and employ technetium-99m, chromium-51, indium-111, and gallium-68, roughly in that order. The extent of usefulness depends on the properties of the label such as the half-life, decay mode, and in-vivo stability, etc. Labeled cells can be used for red cell survival measurements when the half-life of the radionuclide is sufficiently long. The major portion of this article deals with random labels.

  1. Quantification of Depletion-Induced Adhesion of Red Blood Cells

    NASA Astrophysics Data System (ADS)

    Steffen, P.; Verdier, C.; Wagner, C.

    2013-01-01

    Red blood cells (RBCs) are known to form aggregates in the form of rouleaux due to the presence of plasma proteins under physiological conditions. The formation of rouleaux can also be induced in vitro by the addition of macromolecules to the RBC suspension. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly originate from indirect measurements such as flow chamber experiments, but data is lacking at the single cell level. Here, we present measurements on the dextran-induced aggregation of red blood cells using atomic force microscopy-based single cell force spectroscopy. The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs were determined. The results on adhesion energy are in excellent agreement with a model based on the depletion effect and previous experimental studies. Furthermore, our method allowed to determine the adhesion force, a quantity that is needed in theoretical investigations on blood flow.

  2. Quantification of depletion-induced adhesion of red blood cells.

    PubMed

    Steffen, P; Verdier, C; Wagner, C

    2013-01-01

    Red blood cells (RBCs) are known to form aggregates in the form of rouleaux due to the presence of plasma proteins under physiological conditions. The formation of rouleaux can also be induced in vitro by the addition of macromolecules to the RBC suspension. Current data on the adhesion strength between red blood cells in their natural discocyte shapes mostly originate from indirect measurements such as flow chamber experiments, but data is lacking at the single cell level. Here, we present measurements on the dextran-induced aggregation of red blood cells using atomic force microscopy-based single cell force spectroscopy. The effects of dextran concentration and molecular weight on the interaction energy of adhering RBCs were determined. The results on adhesion energy are in excellent agreement with a model based on the depletion effect and previous experimental studies. Furthermore, our method allowed to determine the adhesion force, a quantity that is needed in theoretical investigations on blood flow. PMID:23383842

  3. Pure Red Cell Aplasia Following Interleukin-2 Therapy

    PubMed Central

    Dutcher, Janice P.; Fan, Wen; Wiernik, Peter H.

    2016-01-01

    A 61-year-old woman with metastatic renal cell carcinoma underwent systemic treatment with high-dose interleukin-2 (IL-2). Anemia requiring transfusion of 1 unit of packed red blood cells (PRBCs) was required during the second week of IL-2 therapy. One month following completion of high-dose IL-2 treatment, she was hospitalized for severe, symptomatic anemia and received 5 units of PRBCs. She was referred back for evaluation. A complete hematologic evaluation was performed including antiviral serology, evaluation for hemolysis, complete iron studies, and finally bone marrow aspiration and biopsy. The diagnosis was pure red cell aplasia, and no inciting viral cause could be ascertained. She required PRBCs for 5 months following IL-2 therapy. It was concluded that IL-2 was the cause of her red cell aplasia. This subsequently resolved spontaneously, and she had normal hemoglobin and hematocrit, respectively, 1 and 2 years after treatment. PMID:27144182

  4. A statistical model for red blood cell survival.

    PubMed

    Korell, Julia; Coulter, Carolyn V; Duffull, Stephen B

    2011-01-01

    A statistical model for the survival time of red blood cells (RBCs) with a continuous distribution of cell lifespans is presented. The underlying distribution of RBC lifespans is derived from a probability density function with a bathtub-shaped hazard curve, and accounts for death of RBCs due to senescence (age-dependent increasing hazard rate) and random destruction (constant hazard), as well as for death due to initial or delayed failures and neocytolysis (equivalent to early red cell mortality). The model yields survival times similar to those of previously published studies of RBC survival and is easily amenable to inclusion of drug effects and haemolytic disorders. PMID:20950630

  5. Regulation of red cell membrane protein interactions: implications for red cell function.

    PubMed

    Takakuwa, Y

    2001-03-01

    This article presents new insights into the molecular mechanism for regulating red cell membrane protein interactions that are responsible for erythrocyte membrane mechanical properties. For various skeletal proteins, structure-function correlations of protein 4.1R have been studied in detail. Kinetic analysis with the resonant mirror detection method has determined the nature of 4.1R interactions with various binding partners such as band 3, glycophorin C, and p55, and their binding sites. More importantly, calmodulin (CaM) binds to 4.1R in a Ca2+-independent manner to modulate the 4.1R interactions in the presence of Ca2+ at microM. Crystal structure of the 30-kD domain of 4.1R has a cloverleaf-like architecture with three lobes, each of which contains a binding region specific for binding partners. CaM binds to the grooves situated in two regions between the three lobes, possibly leading to conformational changes of the three lobes with a consequent alteration in the capacity of 4.1R to bind to its partners. The present findings on erythrocyte 4.1R should provide a basis for better understanding the membrane functions of nonerythroid cells. PMID:11224681

  6. In vivo red cell destruction by anti-Lu6

    SciTech Connect

    Issitt, P.D.; Valinsky, J.E.; Marsh, W.L.; DiNapoli, J.; Gutgsell, N.S. )

    1990-03-01

    An example is presented of an IgG1, anti-Lu6, that reacted by indirect antiglobulin test and was capable of destroying antigen-positive red cells in vivo. Two methods for the measurement of red cell survival, {sup 51}Cr labeling and flow cytometry, gave the same result: 20 percent of the test dose of Lu:6 red cells was destroyed in the first hour after injection and 80 percent in the first 24 hours. The clinical relevance of the antibody was correctly predicted by an in vitro monocyte monolayer assay. The finding that this example of anti-Lu6 was clinically significant should not be taken to mean that all antibodies directed against high-incidence Lutheran and Lutheran system-related antigens will behave similarly. When such antibodies are encountered, in vivo and/or in vitro studies to assess their clinical significance are necessary before rare blood is used for transfusion.

  7. Dual network model for red blood cell membranes

    NASA Astrophysics Data System (ADS)

    Boal, David H.; Seifert, Udo; Zilker, Andreas

    1992-12-01

    A two-component network is studied by Monte Carlo simulation to model the lipid/spectrin membrane of red blood cells. The model predicts that the shear modulus decreases rapidly with the maximum length of the model spectrin and should be in the 10-7 J/m2 range for human red blood cells. A simplified model for the isolated spectrin network shows a negative Lamé coefficient λ. Transverse fluctuations of the dual membrane are found to be fluidlike over the range of wavelengths investigated.

  8. Photoacoustic response of suspended and hemolyzed red blood cells

    NASA Astrophysics Data System (ADS)

    Saha, Ratan K.; Karmakar, Subhajit; Roy, Madhusudan

    2013-07-01

    The effect of confinement of hemoglobin molecules on photoacoustic (PA) signal is studied experimentally. The PA amplitudes for samples with suspended red blood cells (SRBCs) and hemolyzed red blood cells (HRBCs) were found to be comparable at each hematocrit for 532 nm illumination. The difference between the corresponding amplitudes increased with increasing hematocrit for 1064 nm irradiation. For example, the PA amplitude for the SRBCs was about 260% higher than that of the HRBCs at 40% hematocrit. This observation may help to develop a PA method detecting hemolysis noninvasively.

  9. Experimental and theoretical bases for mechanisms of antigen discrimination by T cells

    PubMed Central

    Kajita, Masashi K.; Yokota, Ryo; Aihara, Kazuyuki; Kobayashi, Tetsuya J.

    2015-01-01

    Interaction only within specific molecules is a requisite for accurate operations of a biochemical reaction in a cell where bulk of background molecules exist. While structural specificity is a well-established mechanism for specific interaction, biophysical and biochemical experiments indicate that the mechanism is not sufficient for accounting for the antigen discrimination by T cells. In addition, the antigen discrimination by T cells also accompanies three intriguing properties other than the specificity: sensitivity, speed, and concentration compensation. In this work, we review experimental and theoretical works on the antigen discrimination by focusing on these four properties and show future directions towards understanding of the fundamental principle for molecular discrimination. PMID:27493520

  10. Evaluation of the red cell storage lesion after irradiation in filtered packed red cell units

    SciTech Connect

    Hillyer, C.D.; Tiegerman, K.O.; Berkman, E.M. )

    1991-07-01

    Packed red cell units (n = 10) were filtered and divided equally. One-half unit from each donor was irradiated (x) (3500 cGy). On Days 0, 14, 28, and 42, ATP, K+, Na+, lactate dehydrogenase (LDH), plasma-free hemoglobin (PFH), and pH were determined. The reduction in ATP was greater in the irradiated than the nonirradiated (y) units by Day 42 (mean x-y: -70, p = 0.0005). The increase in K+ was greater in the irradiated than nonirradiated units on Days 14, 28, and 42 (mean x-y: 17-20, p = 0.0001). Decrease in pH and increases in LDH and PFH were significant (p less than 0.05) on Day 42 only. K+ increases added only 1.7 to 2.0 mmol per unit, a difference felt to be clinically insignificant. The changes noted in ATP, pH, LDH, and PFH are significant but minimal on Day 42 and imply that viability changes would also be minimal. These biochemical data support the storage of irradiated units for at least 28 days.

  11. Anatomy of the red cell membrane skeleton: unanswered questions.

    PubMed

    Lux, Samuel E

    2016-01-14

    The red cell membrane skeleton is a pseudohexagonal meshwork of spectrin, actin, protein 4.1R, ankyrin, and actin-associated proteins that laminates the inner membrane surface and attaches to the overlying lipid bilayer via band 3-containing multiprotein complexes at the ankyrin- and actin-binding ends of spectrin. The membrane skeleton strengthens the lipid bilayer and endows the membrane with the durability and flexibility to survive in the circulation. In the 36 years since the first primitive model of the red cell skeleton was proposed, many additional proteins have been discovered, and their structures and interactions have been defined. However, almost nothing is known of the skeleton's physiology, and myriad questions about its structure remain, including questions concerning the structure of spectrin in situ, the way spectrin and other proteins bind to actin, how the membrane is assembled, the dynamics of the skeleton when the membrane is deformed or perturbed by parasites, the role lipids play, and variations in membrane structure in unique regions like lipid rafts. This knowledge is important because the red cell membrane skeleton is the model for spectrin-based membrane skeletons in all cells, and because defects in the red cell membrane skeleton underlie multiple hemolytic anemias. PMID:26537302

  12. Fermented red ginseng extract inhibits cancer cell proliferation and viability.

    PubMed

    Oh, Jisun; Jeon, Seong Bin; Lee, Yuri; Lee, Hyeji; Kim, Ju; Kwon, Bo Ra; Yu, Kang-Yeol; Cha, Jeong-Dan; Hwang, Seung-Mi; Choi, Kyung-Min; Jeong, Yong-Seob

    2015-04-01

    Red ginseng (Panax ginseng C.A. Meyer) is the most widely recognized medicinal herb due to its remedial effects in various disorders, such as cancers, diabetes, and heart problems. In this study, we investigated the anticancer effect of fermented red ginseng extract (f-RGE; provided by Jeonju Biomaterials Institute, Jeonju, South Korea) in a parallel comparison with the effect of nonfermented red ginseng extract (nf-RGE; control) on several cancer cell lines--MCF-7 breast cancer cells, HepG2 hepatocellular carcinoma cells, and reprogrammed MCF-7 cells (mimicking cancer stem cells). Cells were cultured at various concentrations of RGE (from 0.5 up to 5 mg/mL) and their viabilities and proliferative properties were examined. Our data demonstrate the following: (1) nf-RGE inhibited cell viability at ≥1 mg/mL for MCF-7 cells and ≥2 mg/mL for HepG2 cells, (2) in the presence of a carcinogenic agent, 12-O-tetradecanoylphorbol-13-acetate (TPA), nf-RGE treatment in combination with paclitaxel synergistically decreased MCF-7 as well as HepG2 cell viability, (3) f-RGE (which contained a greater level of Rg3 content) more effectively decreased the viability of MCF-7 and HepG2 cells compared to nf-RGE, and (4) f-RGE appeared more potent for inhibiting cancerous differentiation of reprogrammed MCF-7 cells in a synergistic fashion with paclitaxel, especially in the presence of TPA, compared to nf-RGE. These findings suggest that f-RGE treatment may be more effective for decreasing cancer cell survival by inducing apoptotic cell death and also presumably for preventing cancer stem cell differentiation compared to nf-RGE. PMID:25658580

  13. Spatial Distributions of Red Blood Cells Significantly Alter Local Haemodynamics

    PubMed Central

    Sherwood, Joseph M.; Holmes, David; Kaliviotis, Efstathios; Balabani, Stavroula

    2014-01-01

    Although bulk changes in red blood cell concentration between vessels have been well characterised, local distributions are generally overlooked. Red blood cells aggregate, deform and migrate within vessels, forming heterogeneous distributions which have considerable effect on local haemodynamics. The present study reports data on the local distribution of human red blood cells in a sequentially bifurcating microchannel, representing the branching geometry of the microvasculature. Imaging methodologies with simple extrapolations are used to infer three dimensional, time-averaged velocity and haematocrit distributions under a range of flow conditions. Strong correlation between the bluntness of the velocity and haematocrit profiles in the parent branch of the geometry is observed and red blood cell aggregation has a notable effect on the observed trends. The two branches of the first bifurcation show similar characteristics in terms of the shapes of the profiles and the extent of plasma skimming, despite the difference in geometric configuration. In the second bifurcation, considerable asymmetry between the branches in the plasma skimming relationship is observed, and elucidated by considering individual haematocrit profiles. The results of the study highlight the importance of considering local haematocrit distributions in the analysis of blood flow and could lead to more accurate computational models of blood flow in microvascular networks. The experimental approaches developed in this work provide a foundation for further examining the characteristics of microhaemodynamics. PMID:24950214

  14. Red Blood Cell Spectrin Skeleton in the Spotlight.

    PubMed

    Braun-Breton, Catherine; Abkarian, Manouk

    2016-02-01

    Das et al. recently reported a role for the major merozoite surface protein MSP1 in malarial parasite egress from the red blood cell (RBC). On the basis of these new data and physical considerations, we propose an updated model for the main steps of this essential process for parasite proliferation. PMID:26652974

  15. Molecular discrimination of phytoseiids associated with the red palm mite Raoiella indica (Acari: Tenuipalpidae) from Mauritius and South Florida.

    PubMed

    Bowman, Heidi M; Hoy, Marjorie A

    2012-08-01

    Phytoseiid populations imported from Mauritius for evaluation for a classical biological control program in Florida, USA, were morphologically identified as Amblyseius largoensis Muma, a species associated with the red palm mite in south Florida and the Caribbean. Bayesian analysis and sequence divergences of the mitochondrial 12S rRNA and nuclear Elongation factor--I alpha (EF-Iα) genes and Neighbor-Joining analysis of High-fidelity-RAPD-PCR markers were used to discriminate between the south Florida and Mauritius populations. High-fidelity-RAPD-PCR markers in addition to Bayesian and sequence divergence analyses of the 12S rRNA sequences suggest that the Mauritius and south Florida populations are genetically different but whether these are species or population differences is unknown. The degenerate EF-Iα primers used to survey the phytoseiids amplified two different elongation factor sequences with distinct amino acid translations, the putative EF-Iα and an unknown elongation factor. Variability within the 12S gene was used to develop population-specific primers for identifying the Mauritius phytoseiids in the event they are released in south Florida. PMID:22527831

  16. Further studies of sodium transport in feline red cells.

    PubMed

    Sha'afi, R I; Pascoe, E

    1973-06-01

    The transport of radioactive sodium in high sodium cat red blood cells has been studied under various experimental conditions. It was found that iodoacetate (IAA) and iodoacetamide (IAM) inhibit Na influx by 50% whereas NaF has no effect. Reversible dyes, such as methylene blue (Mb), also inhibit this influx by 60%. Both IAA and Mb effects show a lag period of about 40 min. Cell starvation abolishes the volume-dependent Na influx which is generally observed in these cells. IAA reduces significantly the volume-dependent Na influx but does not inhibit it completely. 5 mM magnesium chloride produces a twofold increase in Na influx. On the other hand, MgCl(2) has no effect on Na transport in human red cells or on potassium or sulfate transport in cat red cells. The effect of MgCl(2) is quite rapid and does not interfere with the volume-dependent Na influx. This effect is abolished in starved cells. Reincubation of previously stored cells in buffered solutions containing glucose and MgCl(2) causes more than one order of magnitude increase in Na influx. These several observations are discussed in terms of the possibility of a link between Na transport and Na-Mg-activated ATPase. PMID:4733097

  17. Red blood cell replacement, or nanobiotherapeutics with enhanced red blood cell functions?

    PubMed

    Chang, Thomas Ming Swi

    2015-06-01

    Why is this important? Under normal circumstances, donor blood is the best replacement for blood. However, there are exceptions: During natural epidemics (e.g., HIV, Ebola, etc.) or man-made epidemics (terrorism, war, etc.), there is a risk of donor blood being contaminated, and donors being disqualified because they have contracted disease. Unlike red blood cells (RBCs), blood substitutes can be sterilized to remove infective agents. Heart attack and stroke are usually caused by obstruction of arterial blood vessels. Unlike RBCs, which are particulate, blood substitutes are in the form of a solution that can perfuse through obstructed vessels with greater ease to reach the heart and brain, as has been demonstrated in animal studies. Severe blood loss from injuries sustained during accidents, disasters, or war may require urgent blood transfusion that cannot wait for transportation to the hospital for blood group testing. Unlike RBCs, blood substitutes do not have specific blood groups, and can be administered on the spot. RBCs have to be stored under refrigeration for up to 42 days, and are thus difficult to transport and store in times of disaster and at the battlefront. Blood substitutes can be stored at room temperature for more than 1 year, compared to the RBC shelf life of 1 day, at room temperature. In cases of very severe hemorrhagic shock, there is usually a safety window of 60 min for blood replacement, beyond which there could be problems related to irreversible shock. Animal studies show that a particular type of blood substitute, with enhanced RBC enzymes, may be able to prolong the duration of the safety window. PMID:26096663

  18. Red blood cell homeostasis: recognition of distinct types of damaged homologous red blood cells by a mouse macrophage cell line.

    PubMed

    Singer, J A; Morrison, M; Walker, W S

    1987-06-01

    The mouse macrophage (M phi) cell line IC-21 preferentially ingests a subpopulation of homologous red blood cells (MRBC) from normal mice. This subpopulation presumably bears the so-called transfusion lesion, a consequence of damage acquired during the drawing and processing of blood. To determine if all damaged MRBC were recognized by a common receptor site on IC-21 M phi, we prepared suspensions of MRBC damaged in vitro by treatment with tannic acid and compared the phagocytic uptake of these cells with those bearing the transfusion lesion. Trypsin treatment of IC-21 M phi rendered them unable to recognize MRBC bearing the transfusion lesion; but it had no effect on the uptake of tannic acid-damaged MRBC, showing that IC-21 M phi have separate recognition sites for these two populations of damaged MRBC. PMID:3474332

  19. Aggregation of red blood cells: From rouleaux to clot formation

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Steffen, Patrick; Svetina, Saša

    2013-06-01

    Red blood cells are known to form aggregates in the form of rouleaux. This aggregation process is believed to be reversible, but there is still no full understanding on the adhesion mechanism. There are at least two competing models, based either on bridging or on depletion. We review recent experimental results on the single cell level and theoretical analyses of the depletion model and of the influence of the cell shape on the adhesion strength. Another important aggregation mechanism is caused by activation of platelets. This leads to clot formation which is life-saving in the case of wound healing, but also a major cause of death in the case of a thrombus induced stroke. We review historical and recent results on the participation of red blood cells in clot formation.

  20. Calcium movements across the membrane of human red cells

    PubMed Central

    Schatzmann, H. J.; Vincenzi, F. F.

    1969-01-01

    1. A study has been made of the cellular content and movement of Ca across the membrane of human red blood cells. 2. The [Ca] in the cellular contents of fresh red cells is 4·09 × 10-2 mM. The intracellular concentration of free ionic Ca ([Ca2+]) is considered to be less than this value and therefore less than extracellular [Ca2+] under normal conditions. 3. Observation of unidirectional Ca fluxes with 45Ca confirms previous reports of low permeability of the red cell membrane for Ca. After nearly 1 week of loading in the cold, intracellular 45Ca content is 1·8% of extracellular 45Ca content. Appearance in extracellular fluid of 45Ca from coldloaded cells can be considered to arise from two compartments. Efflux of 45Ca from the `slower compartment' is accelerated by the addition of glucose. 4. Starved red cells, incubated at 37° C, after reversible haemolysis for loading with Ca and Mg-ATP, exhibit an outward net transport of Ca against an electrochemical gradient. The transport is associated with the appearance of inorganic phosphate (Pi). Cells treated similarly, but without ATP show no transport and no appearance of Pi. 5. During the initial phase of transport, 1·3 mole Pi appear per mole Ca transported. 6. The transport of Ca from ATP-loaded cells is highly temperature-dependent, with a Q10 of 3·5. 7. Cell membrane adenosine triphosphatase (ATPase) activity of reversibly haemolysed cells is stimulated only by intracellular, and not by extracellular Ca. 8. Neither Ca transport in reversibly haemolysed cells, nor the Ca-Mg activated ATPase of isolated cell membranes is sensitive to Na, K, ouabain or oligomycin. 9. Mg is not transported under the conditions which reveal Ca transport, but Mg appears to be necessary for Ca transport. 10. Sr is transported from reversibly haemolysed Mg-ATP-loaded cells. Sr also can substitute for Ca, but not for Mg, in the activation of membrane ATPase. 11. It is concluded that, in addition to a low passive permeability, an

  1. Red Blood Cell Polymorphism and Susceptibility to Plasmodium vivax

    PubMed Central

    Zimmerman, Peter A.; Ferreira, Marcelo U.; Howes, Rosalind E.; Mercereau-Puijalon, Odile

    2013-01-01

    Resistance to Plasmodium vivax blood-stage infection has been widely recognised to result from absence of the Duffy (Fy) blood group from the surface of red blood cells (RBCs) in individuals of African descent. Interestingly, recent studies from different malaria-endemic regions have begun to reveal new perspectives on the association between Duffy gene polymorphism and P. vivax malaria. In Papua New Guinea and the Americas, heterozygous carriers of a Duffy-negative allele are less susceptible to P. vivax infection than Duffy-positive homozygotes. In Brazil, studies show that the Fya antigen, compared to Fyb, is associated with lower binding to the P. vivax Duffy-binding protein and reduced susceptibility to vivax malaria. Additionally, it is interesting that numerous studies have now shown that P. vivax can infect RBCs and cause clinical disease in Duffy-negative people. This suggests that the relationship between P. vivax and the Duffy antigen is more complex than customarily described. Evidence of P. vivax Duffy-independent red cell invasion indicates that the parasite must be evolving alternative red cell invasion pathways. In this chapter, we review the evidence for P. vivax Duffy-dependent and Duffy-independent red cell invasion. We also consider the influence of further host gene polymorphism associated with malaria endemicity on susceptibility to vivax malaria. The interaction between the parasite and the RBC has significant potential to influence the effectiveness of P. vivax-specific vaccines and drug treatments. Ultimately, the relationships between red cell polymorphisms and P. vivax blood-stage infection will influence our estimates on the population at risk and efforts to eliminate vivax malaria. PMID:23384621

  2. Red blood cell and iron metabolism during space flight.

    PubMed

    Smith, Scott M

    2002-10-01

    Space flight anemia is a widely recognized phenomenon in astronauts. Reduction in circulating red blood cells and plasma volume results in a 10% to 15% decrement in circulatory volume. This effect appears to be a normal physiologic adaptation to weightlessness and results from the removal of newly released blood cells from the circulation. Iron availability increases, and (in the few subjects studied) iron stores increase during long-duration space flight. The consequences of these changes are not fully understood. PMID:12361780

  3. Red blood cell and iron metabolism during space flight

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.

    2002-01-01

    Space flight anemia is a widely recognized phenomenon in astronauts. Reduction in circulating red blood cells and plasma volume results in a 10% to 15% decrement in circulatory volume. This effect appears to be a normal physiologic adaptation to weightlessness and results from the removal of newly released blood cells from the circulation. Iron availability increases, and (in the few subjects studied) iron stores increase during long-duration space flight. The consequences of these changes are not fully understood.

  4. Backward elastic light scattering of malaria infected red blood cells

    NASA Astrophysics Data System (ADS)

    Lee, Seungjun; Lu, Wei

    2011-08-01

    We investigated the backward light scattering pattern of healthy and malaria (Plasmodium falciparum) parasitized red blood cells. The spectrum could clearly distinguish between predominant ring stage infected blood cells and healthy blood cells. Further, we found that infected samples mixed with different stages of P. falciparum showed different signals, suggesting that even variance in parasite stages could also be detected by the spectrum. These results together with the backward scattering technique suggest the potential of non-invasive diagnosis of malaria through light scattering of blood cells near the surface of human body, such as using eyes or skin surface.

  5. Intracellular energetic units in red muscle cells.

    PubMed Central

    Saks, V A; Kaambre, T; Sikk, P; Eimre, M; Orlova, E; Paju, K; Piirsoo, A; Appaix, F; Kay, L; Regitz-Zagrosek, V; Fleck, E; Seppet, E

    2001-01-01

    The kinetics of regulation of mitochondrial respiration by endogenous and exogenous ADP in muscle cells in situ was studied in skinned cardiac and skeletal muscle fibres. Endogenous ADP production was initiated by addition of MgATP; under these conditions the respiration rate and ADP concentration in the medium were dependent on the calcium concentration, and 70-80% of maximal rate of respiration was achieved at ADP concentration below 20 microM in the medium. In contrast, when exogenous ADP was added, maximal respiration rate was observed only at millimolar concentrations. An exogenous ADP-consuming system consisting of pyruvate kinase (PK; 20-40 units/ml) and phosphoenolpyruvate (PEP; 5 mM), totally suppressed respiration activated by exogenous ADP, but the respiration maintained by endogenous ADP was not suppressed by more than 20-40%. Creatine (20 mM) further activated respiration in the presence of ATP and PK+PEP. Short treatment with trypsin (50-500 nM for 5 min) decreased the apparent K(m) for exogenous ADP from 300-350 microM to 50-60 microM, increased inhibition of respiration by PK+PEP system up to 70-80%, with no changes in MgATPase activity and maximal respiration rates. Electron-microscopic observations showed detachment of mitochondria and disordering of the regular structure of the sarcomere after trypsin treatment. Two-dimensional electrophoresis revealed a group of at least seven low-molecular-mass proteins in cardiac skinned fibres which were very sensitive to trypsin and not present in glycolytic fibres, which have low apparent K(m) for exogenous ADP. It is concluded that, in oxidative muscle cells, mitochondria are incorporated into functional complexes ('intracellular energetic units') with adjacent ADP-producing systems in myofibrils and in sarcoplasmic reticulum, probably due to specific interaction with cytoskeletal elements responsible for mitochondrial distribution in the cell. It is suggested that these complexes represent the basic

  6. Membranotropic photobiomodulation on red blood cell deformability

    NASA Astrophysics Data System (ADS)

    Luo, Gang-Yue; Zhao, Yan-Ping; Liu, Timon C.; Liu, Song-Hao

    2007-05-01

    To assess modulation of laser on erythrocyte permeability and deformability via cell morphology changes, healthy human echinocytes with shrinking size and high plasmic viscosity due to cellular dehydration were treated with 1 mW, 2 mW, 3 mW, and 5 mW laser power exposure respectively. Image analyzing system on single intact erythrocyte was applied for measuring comprehensive cell morphological parameters (surface area, external membrane perimeter, circle index and elongation index) that were determined by the modulation of erythrocyte water permeability and deformability to detect relationship between erythrocyte water permeability alteration and deformability. Our preliminary experiment showed that exposure under light dose of 5 mW for 5 min could induce more active erythrocyte swelling and deformation. water channel aquaporin-1(AQP-1) was inhibited by the incubation of HgCl II in the presence and absence of 5 mW laser irradiation. The result suggested that osmotic water permeability is a primary factor in the procedure of erythrocyte deformability. In addition, no modulation of laser(5mW) on erythrocyte deformability had been found when the echinocytes were cultured with GDP-β-S (G protein inhibitor).

  7. Red blood cell sodium heteroexchange in familial primary hypertrophic cardiomyopathy.

    PubMed

    Semplicini, A; Mozzato, M G; Bongiovi, S; Marzola, M; Macor, F; Ceolotto, G; Serena, L; Pessina, A C

    1994-03-01

    The hallmark of primary hypertrophic cardiomyopathy is an inappropriate myocardial hypertrophy, linked to myofibril disarray of the left ventricle. Its variable clinical expression may be due to genetic heterogeneity and variable penetrance. Since we have recently shown that abnormalities of cation transport in the erythrocytes are associated with cardiac hypertrophy in essential hypertensives and insulin-dependent diabetics, we have investigated the relationship between cardiac anatomy and function and red cell Li+/Na+ and Na+/H+ exchange in 33 relatives of a patient who died of cardiac failure and was found to have a primary hypertrophic cardiomyopathy at autopsy. According to echocardiographic examination, 11 members of the family also had a hypertrophic cardiomyopathy, with a family distribution compatible with autosomal dominant genetic transmission and variable penetrance. Red cell Li+/Na+ and Na+/H+ exchange were not significantly different in the affected members as compared to the unaffected, but in the former, after correction for potentially confounding variables, interventricular septum thickness was positively correlated to Na+/H+ exchange and diastolic function (Area E/Area A and Vmax E/Vmax A) negatively correlated to Li+/Na+ exchange. Since a generalized overactivity of the cell membrane Na+/H+ exchange, reflected by increased Na+/H+ and Li+/Na+ exchanges in the red cells, could favour cellular growth and diastolic dysfunction, our data suggest that abnormalities of cell membrane cation transport could play a role in the phenotypic expression of hypertrophic cardiomyopathy. PMID:8013504

  8. Alterations of Red Cell Membrane Properties in Nneuroacanthocytosis

    PubMed Central

    Siegl, Claudia; Hamminger, Patricia; Jank, Herbert; Ahting, Uwe; Bader, Benedikt; Danek, Adrian; Gregory, Allison; Hartig, Monika; Hayflick, Susan; Hermann, Andreas; Prokisch, Holger; Sammler, Esther M.; Yapici, Zuhal; Prohaska, Rainer; Salzer, Ulrich

    2013-01-01

    Neuroacanthocytosis (NA) refers to a group of heterogenous, rare genetic disorders, namely chorea acanthocytosis (ChAc), McLeod syndrome (MLS), Huntington’s disease-like 2 (HDL2) and pantothenate kinase associated neurodegeneration (PKAN), that mainly affect the basal ganglia and are associated with similar neurological symptoms. PKAN is also assigned to a group of rare neurodegenerative diseases, known as NBIA (neurodegeneration with brain iron accumulation), associated with iron accumulation in the basal ganglia and progressive movement disorder. Acanthocytosis, the occurrence of misshaped erythrocytes with thorny protrusions, is frequently observed in ChAc and MLS patients but less prevalent in PKAN (about 10%) and HDL2 patients. The pathological factors that lead to the formation of the acanthocytic red blood cell shape are currently unknown. The aim of this study was to determine whether NA/NBIA acanthocytes differ in their functionality from normal erythrocytes. Several flow-cytometry-based assays were applied to test the physiological responses of the plasma membrane, namely drug-induced endocytosis, phosphatidylserine exposure and calcium uptake upon treatment with lysophosphatidic acid. ChAc red cell samples clearly showed a reduced response in drug-induced endovesiculation, lysophosphatidic acid-induced phosphatidylserine exposure, and calcium uptake. Impaired responses were also observed in acanthocyte-positive NBIA (PKAN) red cells but not in patient cells without shape abnormalities. These data suggest an “acanthocytic state” of the red cell where alterations in functional and interdependent membrane properties arise together with an acanthocytic cell shape. Further elucidation of the aberrant molecular mechanisms that cause this acanthocytic state may possibly help to evaluate the pathological pathways leading to neurodegeneration. PMID:24098554

  9. Alterations of red cell membrane properties in neuroacanthocytosis.

    PubMed

    Siegl, Claudia; Hamminger, Patricia; Jank, Herbert; Ahting, Uwe; Bader, Benedikt; Danek, Adrian; Gregory, Allison; Hartig, Monika; Hayflick, Susan; Hermann, Andreas; Prokisch, Holger; Sammler, Esther M; Yapici, Zuhal; Prohaska, Rainer; Salzer, Ulrich

    2013-01-01

    Neuroacanthocytosis (NA) refers to a group of heterogenous, rare genetic disorders, namely chorea acanthocytosis (ChAc), McLeod syndrome (MLS), Huntington's disease-like 2 (HDL2) and pantothenate kinase associated neurodegeneration (PKAN), that mainly affect the basal ganglia and are associated with similar neurological symptoms. PKAN is also assigned to a group of rare neurodegenerative diseases, known as NBIA (neurodegeneration with brain iron accumulation), associated with iron accumulation in the basal ganglia and progressive movement disorder. Acanthocytosis, the occurrence of misshaped erythrocytes with thorny protrusions, is frequently observed in ChAc and MLS patients but less prevalent in PKAN (about 10%) and HDL2 patients. The pathological factors that lead to the formation of the acanthocytic red blood cell shape are currently unknown. The aim of this study was to determine whether NA/NBIA acanthocytes differ in their functionality from normal erythrocytes. Several flow-cytometry-based assays were applied to test the physiological responses of the plasma membrane, namely drug-induced endocytosis, phosphatidylserine exposure and calcium uptake upon treatment with lysophosphatidic acid. ChAc red cell samples clearly showed a reduced response in drug-induced endovesiculation, lysophosphatidic acid-induced phosphatidylserine exposure, and calcium uptake. Impaired responses were also observed in acanthocyte-positive NBIA (PKAN) red cells but not in patient cells without shape abnormalities. These data suggest an "acanthocytic state" of the red cell where alterations in functional and interdependent membrane properties arise together with an acanthocytic cell shape. Further elucidation of the aberrant molecular mechanisms that cause this acanthocytic state may possibly help to evaluate the pathological pathways leading to neurodegeneration. PMID:24098554

  10. Disinhibition of olfactory bulb granule cells accelerates odour discrimination in mice

    PubMed Central

    Nunes, Daniel; Kuner, Thomas

    2015-01-01

    Granule cells are the dominant cell type of the olfactory bulb inhibiting mitral and tufted cells via dendrodendritic synapses; yet the factors regulating the strength of their inhibitory output, and, therefore, their impact on odour discrimination, remain unknown. Here we show that GABAAR β3-subunits are distributed in a somatodendritic pattern, mostly sparing the large granule cell spines also known as gemmules. Granule cell-selective deletion of β3-subunits nearly abolishes spontaneous and muscimol-induced currents mediated by GABAA receptors in granule cells, yet recurrent inhibition of mitral cells is strongly enhanced. Mice with disinhibited granule cells require less time to discriminate both dissimilar as well as highly similar odourants, while discrimination learning remains unaffected. Hence, granule cells are controlled by an inhibitory drive that in turn tunes mitral cell inhibition. As a consequence, the olfactory bulb inhibitory network adjusts the speed of early sensory processing. PMID:26592770

  11. Disinhibition of olfactory bulb granule cells accelerates odour discrimination in mice.

    PubMed

    Nunes, Daniel; Kuner, Thomas

    2015-01-01

    Granule cells are the dominant cell type of the olfactory bulb inhibiting mitral and tufted cells via dendrodendritic synapses; yet the factors regulating the strength of their inhibitory output, and, therefore, their impact on odour discrimination, remain unknown. Here we show that GABAAR β3-subunits are distributed in a somatodendritic pattern, mostly sparing the large granule cell spines also known as gemmules. Granule cell-selective deletion of β3-subunits nearly abolishes spontaneous and muscimol-induced currents mediated by GABAA receptors in granule cells, yet recurrent inhibition of mitral cells is strongly enhanced. Mice with disinhibited granule cells require less time to discriminate both dissimilar as well as highly similar odourants, while discrimination learning remains unaffected. Hence, granule cells are controlled by an inhibitory drive that in turn tunes mitral cell inhibition. As a consequence, the olfactory bulb inhibitory network adjusts the speed of early sensory processing. PMID:26592770

  12. Oxidative inhibition of red blood cell ATPases by glyceraldehyde.

    PubMed

    Mira, M L; Martinho, F; Azevedo, M S; Manso, C F

    1991-11-01

    Glyceraldehyde and other simple monosaccharides autoxidize under physiological conditions, forming dicarbonyl compounds and hydrogen peroxide via intermediate free radicals. These products may have deleterious effects on cell components. In this paper we study the effect of glyceraldehyde autoxidation on red-cell ATPase activities. The autoxidation of glyceraldehyde in imidazole-glycylglycine buffer, measured by oxygen consumption, depends on the buffer concentration and decreases in the presence of superoxide dismutase and catalase. The addition of DETAPAC inhibits the autoxidation almost completely. When human red-blood-cell membranes are incubated with glyceraldehyde, the red-blood-cell ATPase activities decrease significantly. The addition of DETAPAC, GSH and DTE (dithioerythritol) protects the enzyme from inactivation, but superoxide dismutase and catalase have no effect. Methylglyoxal (a dicarbonyl which is analogous to hydroxypyruvaldehyde derived from glyceraldehyde autoxidation) proved to have a powerful inhibitory action on ATPase activities. The addition of DTE completely protects the enzyme from inactivation, suggesting that the sulphydryl groups of the active site of the enzyme are the critical targets for dicarbonyl compounds. PMID:1836354

  13. Hypochromicity in red blood cells: an experimental and theoretical investigation

    PubMed Central

    Nonoyama, Akihisa; Garcia-Lopez, Alicia; Garcia-Rubio, Luis H.; Leparc, German F.; Potter, Robert L.

    2011-01-01

    Multiwavelength UV-visible transmission spectrophotometry is a useful tool for the examination of micron-size particle suspensions in the context of particle size and chemical composition. This paper reports the reliability of this method to characterize the spectra of purified red blood cells both in their physiological state and with modified hemoglobin content. Previous studies have suggested the contribution of hypochromism on the particle spectra caused by the close electronic interaction of the encapsulated chromophores. Our research shows, however, that this perceived hypochromism can be accounted for by considering two important issues: the acceptance angle of the instrument and the combined scattering and absorption effect of light on the particles. In order to establish these ideas, spectral analysis was performed on purified and modified red cells where the latter was accomplished with a modified hypotonic shock protocol that altered the hemoglobin concentration within the cells. Moreover, the Mie theory was used to successfully simulate the spectral features and trends of the red cells. With this combination of experimental and theoretical exploration, definition of hypochromism has been extended to two subcategories. PMID:21833353

  14. Method using CO for extending the useful shelf-life of refrigerated red blood cells

    DOEpatents

    Bitensky, Mark W.

    1995-01-01

    Method using CO for extending the useful shelf-life of refrigerated red blood cells. Carbon monoxide is utilized for stabilizing hemoglobin in red blood cells to be stored at low temperature. Changes observed in the stored cells are similar to those found in normal red cell aging in the body, the extent thereof being directly related to the duration of refrigerated storage. Changes in cell buoyant density, vesiculation, and the tendency of stored cells to bind autologous IgG antibody directed against polymerized band 3 IgG, all of which are related to red blood cell senescence and increase with refrigerated storage time, have been substantially slowed when red blood cells are treated with CO. Removal of the carbon monoxide from the red blood cells is readily and efficiently accomplished by photolysis in the presence of oxygen so that the stored red blood cells may be safely transfused into a recipient.

  15. Method using CO for extending the useful shelf-life of refrigerated red blood cells

    DOEpatents

    Bitensky, M.W.

    1995-12-19

    A method is disclosed using CO for extending the useful shelf-life of refrigerated red blood cells. Carbon monoxide is utilized for stabilizing hemoglobin in red blood cells to be stored at low temperature. Changes observed in the stored cells are similar to those found in normal red cell aging in the body, the extent thereof being directly related to the duration of refrigerated storage. Changes in cell buoyant density, vesiculation, and the tendency of stored cells to bind autologous IgG antibody directed against polymerized band 3 IgG, all of which are related to red blood cell senescence and increase with refrigerated storage time, have been substantially slowed when red blood cells are treated with CO. Removal of the carbon monoxide from the red blood cells is readily and efficiently accomplished by photolysis in the presence of oxygen so that the stored red blood cells may be safely transfused into a recipient. 5 figs.

  16. Online biomedical resources for malaria-related red cell disorders.

    PubMed

    Piel, Frédéric B; Howes, Rosalind E; Nyangiri, Oscar A; Moyes, Catherine L; Williams, Thomas N; Weatherall, David J; Hay, Simon I

    2013-07-01

    Warnings about the expected increase of the global public health burden of malaria-related red cell disorders are accruing. Past and present epidemiological data are necessary to track spatial and temporal changes in the frequencies of these genetic disorders. A number of open access biomedical databases including data on malaria-related red cell disorders have been launched over the last two decades. Here, we review the content of these databases, most of which focus on genetic diversity, and we describe a new epidemiological resource developed by the Malaria Atlas Project. To tackle upcoming public health challenges, the integration of epidemiological and genetic data is important. As many countries are considering implementing national screening programs, strategies to make such data more accessible are also needed. PMID:23568771

  17. Color contrast of red blood cells on solid substrate

    NASA Astrophysics Data System (ADS)

    Paiziev, Adkham A.

    2013-02-01

    In present study we developed the new method of colour visualization of red blood cells without using any chemical staining. The method based on physical phenomena a white light interference on thin transparent films. It is shown that in the case of thin human blood smears colour interference contrast occurs on solid polished substrates. The best contrast shows substrates with maximal refractive index (Mo, W, Si). These materials have been selected as substrate instead of ordinary microscopic slide in reflected light microscopy. It is shown that reflection of incident white light from blood cell surface and boundary cell-substrate generate two coherent lights. The second one (object signal) after passing through red blood cell gathers additional phase and after interference interaction with reference signal (light reflected from outer cell surface) enables cell image in colour. Number of blood smears of healthy persons (control) and patients who were diagnosed with cancer are presented. It is concluded that the offered method may be used as an effective diagnostic tool to detect early stage blood cells lesion by its interference painting in white light. Offered method may be used in research laboratories, hospitals, diagnostic centres, emergency medicine and other as complementary diagnostic tool to present convenient optical and electron microscopy technique.

  18. Characterization of red blood cells (RBCs) using dual Brillouin/Raman micro-spectroscopy

    NASA Astrophysics Data System (ADS)

    Meng, Zhaokai; Bustamante-Lopez, Sandra C.; Yakovlev, Vladislav V.; Meissner, Kenith E.

    2016-04-01

    Erythrocytes, or red blood cells, transport oxygen to and carbon dioxide from the body's tissues and organs. Red blood cell mechanical properties are altered in a number of diseases such as sickle cell anaemia and malaria. Additionally, mechanically modified red blood cell ghosts are being considered as a long-term, biocompatible carrier for drug delivery and for blood analyte sensing. Brillouin spectroscopy enables viscoelastic characterization of samples at the microscale. In this report, Brillouin spectroscopy is applied to characterize the mechanical properties of red blood cells and red blood cell ghosts.

  19. [Management of feto-maternal red cell allo-immunizations].

    PubMed

    Bricca, P; Guinchard, E; Guitton Bliem, C

    2011-04-01

    Feto-maternal red cell alloimmunization is defined by the presence in a pregnant woman of alloantibodies directed against blood group antigens present on the red blood cells of the fetus and inherited from the father. It arises from the immune response to a first contact to these same antigens during a prior transfusion, transplant or pregnancy. The placental transfer and the fixation of the antibodies on the fetal red cells antigenic targets lead to a haemolysis in the fetus and the newborn. The resulting haemolytic disease can show different clinical forms, from a mild anaemia with neonatal hyperbilirubinemia to a major fetal damage with stillbirth caused by hydrops fetalis. The objective of management strategies of feto-maternal alloimmunization is to detect and monitor maternal alloimmunization and to appreciate the effects on the fetus or the newborn. Since a few years, some new non-invasive techniques of surveillance are used, for instance fetal RHD genotyping on maternal plasma and evaluation of fetal anaemia through velocimetry measurement of the blood flow in the middle cerebral artery. The need for a careful postnatal surveillance has to be emphasized due to the neonatal anaemia, which can be prolonged, and to the resurgence of cases of severe neonatal icteruses recently reported by the Académie de Médecine. The policy of prevention of anti-RH1 alloimmunization should also benefit from the evolution of biological techniques by allowing an improved targeting of concerned women. PMID:21397546

  20. Hemoglobin Aggregation in Single Red Blood Cells of Sickle Cell Anemia

    NASA Astrophysics Data System (ADS)

    Nishio, Izumi; Tanaka, Toyoichi; Sun, Shao-Tang; Imanishi, Yuri; Tsuyoshi Ohnishi, S.

    1983-06-01

    A laser light scattering technique was used to observe the extent of hemoglobin aggregation in solitary red blood cells of sickle cell anemia. Hemoglobin aggregation was confirmed in deoxygenated cells. The light scattering technique can also be applied to cytoplasmic studies of any biological cell.

  1. Red blood cell clustering in Poiseuille microcapillary flow

    NASA Astrophysics Data System (ADS)

    Tomaiuolo, Giovanna; Lanotte, Luca; Ghigliotti, Giovanni; Misbah, Chaouqi; Guido, Stefano

    2012-05-01

    Red blood cells (RBC) flowing in microcapillaries tend to associate into clusters, i.e., small trains of cells separated from each other by a distance comparable to cell size. This process is usually attributed to slower RBCs acting to create a sequence of trailing cells. Here, based on the first systematic investigation of collective RBC flow behavior in microcapillaries in vitro by high-speed video microscopy and numerical simulations, we show that RBC size polydispersity within the physiological range does not affect cluster stability. Lower applied pressure drops and longer residence times favor larger RBC clusters. A limiting cluster length, depending on the number of cells in a cluster, is found by increasing the applied pressure drop. The insight on the mechanism of RBC clustering provided by this work can be applied to further our understanding of RBC aggregability, which is a key parameter implicated in clotting and thrombus formation.

  2. Shape anisotropy induces rotations in optically trapped red blood cells

    NASA Astrophysics Data System (ADS)

    Bambardekar, Kapil; Dharmadhikari, Jayashree A.; Dharmadhikari, Aditya K.; Yamada, Toshihoro; Kato, Tsuyoshi; Kono, Hirohiko; Fujimura, Yuichi; Sharma, Shobhona; Mathur, Deepak

    2010-07-01

    A combined experimental and theoretical study is carried out to probe the rotational behavior of red blood cells (RBCs) in a single beam optical trap. We induce shape changes in RBCs by altering the properties of the suspension medium in which live cells float. We find that certain shape anisotropies result in the rotation of optically trapped cells. Indeed, even normal (healthy) RBCs can be made to rotate using linearly polarized trapping light by altering the osmotic stress the cells are subjected to. Hyperosmotic stress is found to induce shape anisotropies. We also probe the effect of the medium's viscosity on cell rotation. The observed rotations are modeled using a Langevin-type equation of motion that takes into account frictional forces that are generated as RBCs rotate in the medium. We observe good correlation between our measured data and calculated results.

  3. Red Blood Cell Membrane-Cloaked Nanoparticles For Drug Delivery

    NASA Astrophysics Data System (ADS)

    Carpenter, Cody Westcott

    Herein we describe the development of the Red Blood Cell coated nanoparticle, RBC-NP. Purified natural erythrocyte membrane is used to coat drug-loaded poly(lacticco-glycolic acid) (PLGA). Synthetic PLGA co-polymer is biocompatible and biodegradable and has already received US FDA approval for drug-delivery and diagnostics. This work looks specifically at the retention of immunosuppressive proteins on RBC-NPs, right-sidedness of natural RBC membranes interfacing with synthetic polymer nanoparticles, sustained and retarded drug release of RBC-NPs as well as further surface modification of RBC-NPs for increased targeting of model cancer cell lines.

  4. Monoclonal gammopathy-associated pure red cell aplasia.

    PubMed

    Korde, Neha; Zhang, Yong; Loeliger, Kelsey; Poon, Andrea; Simakova, Olga; Zingone, Adriana; Costello, Rene; Childs, Richard; Noel, Pierre; Silver, Samuel; Kwok, Mary; Mo, Clifton; Young, Neal; Landgren, Ola; Sloand, Elaine; Maric, Irina

    2016-06-01

    Pure red cell aplasia (PRCA) is a rare disorder characterized by inhibition of erythroid precursors in the bone marrow and normochromic, normocytic anaemia with reticulocytopenia. Among 51 PRCA patients, we identified 12 (24%) patients having monoclonal gammopathy, monoclonal gammopathy of undetermined significance or smouldering multiple myeloma, with presence of monoclonal protein or abnormal serum free light chains and atypical bone marrow features of clonal plasmacytosis, hypercellularity and fibrosis. Thus far, three patients treated with anti-myeloma based therapeutics have responded with reticulocyte recovery and clinical transfusion independence, suggesting plasma cells play a key role in the pathogenesis of this specific monoclonal gammopathy-associated PRCA. PMID:26999424

  5. Home improvements: malaria and the red blood cell.

    PubMed

    Foley, M; Tilley, L

    1995-11-01

    In real-estate agent's terms, the red blood cell is a renovator's dream. The mature human erythrocyte has no internal organelles, no protein synthesis machinery and no infrastructure for protein trafficking. The malaria parasite invades this empty shell and effectively converts the erythrocyte back into a fully functional eukaryotic cell. In this article, Michael Foley and Leann Tilley examine the Plasmodium falciparum proteins that interact with the membrane skeleton at different stages of the infection and speculate on the roles of these proteins in the remodelling process. PMID:15275396

  6. Rapid and Label-Free Separation of Burkitt's Lymphoma Cells from Red Blood Cells by Optically-Induced Electrokinetics

    PubMed Central

    Liang, Wenfeng; Zhao, Yuliang; Liu, Lianqing; Wang, Yuechao; Dong, Zaili; Li, Wen Jung; Lee, Gwo-Bin; Xiao, Xiubin; Zhang, Weijing

    2014-01-01

    Early stage detection of lymphoma cells is invaluable for providing reliable prognosis to patients. However, the purity of lymphoma cells in extracted samples from human patients' marrow is typically low. To address this issue, we report here our work on using optically-induced dielectrophoresis (ODEP) force to rapidly purify Raji cells' (a type of Burkitt's lymphoma cell) sample from red blood cells (RBCs) with a label-free process. This method utilizes dynamically moving virtual electrodes to induce negative ODEP force of varying magnitudes on the Raji cells and RBCs in an optically-induced electrokinetics (OEK) chip. Polarization models for the two types of cells that reflect their discriminate electrical properties were established. Then, the cells' differential velocities caused by a specific ODEP force field were obtained by a finite element simulation model, thereby established the theoretical basis that the two types of cells could be separated using an ODEP force field. To ensure that the ODEP force dominated the separation process, a comparison of the ODEP force with other significant electrokinetics forces was conducted using numerical results. Furthermore, the performance of the ODEP-based approach for separating Raji cells from RBCs was experimentally investigated. The results showed that these two types of cells, with different concentration ratios, could be separated rapidly using externally-applied electrical field at a driven frequency of 50 kHz at 20 Vpp. In addition, we have found that in order to facilitate ODEP-based cell separation, Raji cells' adhesion to the OEK chip's substrate should be minimized. This paper also presents our experimental results of finding the appropriate bovine serum albumin concentration in an isotonic solution to reduce cell adhesion, while maintaining suitable medium conductivity for electrokinetics-based cell separation. In short, we have demonstrated that OEK technology could be a promising tool for efficient and

  7. Rapid and label-free separation of Burkitt's lymphoma cells from red blood cells by optically-induced electrokinetics.

    PubMed

    Liang, Wenfeng; Zhao, Yuliang; Liu, Lianqing; Wang, Yuechao; Dong, Zaili; Li, Wen Jung; Lee, Gwo-Bin; Xiao, Xiubin; Zhang, Weijing

    2014-01-01

    Early stage detection of lymphoma cells is invaluable for providing reliable prognosis to patients. However, the purity of lymphoma cells in extracted samples from human patients' marrow is typically low. To address this issue, we report here our work on using optically-induced dielectrophoresis (ODEP) force to rapidly purify Raji cells' (a type of Burkitt's lymphoma cell) sample from red blood cells (RBCs) with a label-free process. This method utilizes dynamically moving virtual electrodes to induce negative ODEP force of varying magnitudes on the Raji cells and RBCs in an optically-induced electrokinetics (OEK) chip. Polarization models for the two types of cells that reflect their discriminate electrical properties were established. Then, the cells' differential velocities caused by a specific ODEP force field were obtained by a finite element simulation model, thereby established the theoretical basis that the two types of cells could be separated using an ODEP force field. To ensure that the ODEP force dominated the separation process, a comparison of the ODEP force with other significant electrokinetics forces was conducted using numerical results. Furthermore, the performance of the ODEP-based approach for separating Raji cells from RBCs was experimentally investigated. The results showed that these two types of cells, with different concentration ratios, could be separated rapidly using externally-applied electrical field at a driven frequency of 50 kHz at 20 Vpp. In addition, we have found that in order to facilitate ODEP-based cell separation, Raji cells' adhesion to the OEK chip's substrate should be minimized. This paper also presents our experimental results of finding the appropriate bovine serum albumin concentration in an isotonic solution to reduce cell adhesion, while maintaining suitable medium conductivity for electrokinetics-based cell separation. In short, we have demonstrated that OEK technology could be a promising tool for efficient and

  8. Flow of Red Blood Cells in Stenosed Microvessels

    NASA Astrophysics Data System (ADS)

    Vahidkhah, Koohyar; Balogh, Peter; Bagchi, Prosenjit

    2016-06-01

    A computational study is presented on the flow of deformable red blood cells in stenosed microvessels. It is observed that the Fahraeus-Lindqvist effect is significantly enhanced due to the presence of a stenosis. The apparent viscosity of blood is observed to increase by several folds when compared to non-stenosed vessels. An asymmetric distribution of the red blood cells, caused by geometric focusing in stenosed vessels, is observed to play a major role in the enhancement. The asymmetry in cell distribution also results in an asymmetry in average velocity and wall shear stress along the length of the stenosis. The discrete motion of the cells causes large time-dependent fluctuations in flow properties. The root-mean-square of flow rate fluctuations could be an order of magnitude higher than that in non-stenosed vessels. Several folds increase in Eulerian velocity fluctuation is also observed in the vicinity of the stenosis. Surprisingly, a transient flow reversal is observed upstream a stenosis but not downstream. The asymmetry and fluctuations in flow quantities and the flow reversal would not occur in absence of the cells. It is concluded that the flow physics and its physiological consequences are significantly different in micro- versus macrovascular stenosis.

  9. Flow of Red Blood Cells in Stenosed Microvessels.

    PubMed

    Vahidkhah, Koohyar; Balogh, Peter; Bagchi, Prosenjit

    2016-01-01

    A computational study is presented on the flow of deformable red blood cells in stenosed microvessels. It is observed that the Fahraeus-Lindqvist effect is significantly enhanced due to the presence of a stenosis. The apparent viscosity of blood is observed to increase by several folds when compared to non-stenosed vessels. An asymmetric distribution of the red blood cells, caused by geometric focusing in stenosed vessels, is observed to play a major role in the enhancement. The asymmetry in cell distribution also results in an asymmetry in average velocity and wall shear stress along the length of the stenosis. The discrete motion of the cells causes large time-dependent fluctuations in flow properties. The root-mean-square of flow rate fluctuations could be an order of magnitude higher than that in non-stenosed vessels. Several folds increase in Eulerian velocity fluctuation is also observed in the vicinity of the stenosis. Surprisingly, a transient flow reversal is observed upstream a stenosis but not downstream. The asymmetry and fluctuations in flow quantities and the flow reversal would not occur in absence of the cells. It is concluded that the flow physics and its physiological consequences are significantly different in micro- versus macrovascular stenosis. PMID:27319318

  10. Effects of ethanol on red blood cell rheological behavior

    PubMed Central

    Rabai, M.; Detterich, J.A.; Wenby, R.B.; Toth, K.; Meiselman, H.J.

    2016-01-01

    Consumption of red wine is associated with a decreased risk of several cardiovascular diseases (e.g., coronary artery disease, stroke), but unfortunately literature reports regarding ethanol’s effects on hemorheological parameters are not concordant. In the present study, red blood cell (RBC) deformability was tested via laser ektacytometry (LORCA, 0.3 – 30 Pa) using two approaches: 1) addition of ethanol to whole blood at 0.25% – 2% followed by incubation and testing in ethanol-free LORCA medium; 2) addition of ethanol to the LORCA medium at 0.25% – 6% then testing untreated native RBC in these media. The effects of ethanol on deformability for oxidatively stressed RBC were investigated as were changes of RBC aggregation (Myrenne Aggregometer) for cells in autologous plasma or 3% 70 kDa dextran. Significant dose-related increases of RBC deformability were observed at 0.25% (p<0.05) and higher concentrations only if ethanol was in the LORCA medium; no changes occurred for cells previously incubated with ethanol then tested in ethanol-free medium. The impaired deformability of cells pre-exposed to oxidative stress was improved only if ethanol was in the LORCA medium. RBC aggregation decreased with concentration at 0.25% and higher for cells in both autologous plasma and dextran 70. Our results indicate that ethanol reversibly improves erythrocyte deformability and irreversibly decreases erythrocyte aggregation; the relevance of these results to the health benefits of moderate wine consumption require further investigation. PMID:23089886

  11. Flow of Red Blood Cells in Stenosed Microvessels

    PubMed Central

    Vahidkhah, Koohyar; Balogh, Peter; Bagchi, Prosenjit

    2016-01-01

    A computational study is presented on the flow of deformable red blood cells in stenosed microvessels. It is observed that the Fahraeus-Lindqvist effect is significantly enhanced due to the presence of a stenosis. The apparent viscosity of blood is observed to increase by several folds when compared to non-stenosed vessels. An asymmetric distribution of the red blood cells, caused by geometric focusing in stenosed vessels, is observed to play a major role in the enhancement. The asymmetry in cell distribution also results in an asymmetry in average velocity and wall shear stress along the length of the stenosis. The discrete motion of the cells causes large time-dependent fluctuations in flow properties. The root-mean-square of flow rate fluctuations could be an order of magnitude higher than that in non-stenosed vessels. Several folds increase in Eulerian velocity fluctuation is also observed in the vicinity of the stenosis. Surprisingly, a transient flow reversal is observed upstream a stenosis but not downstream. The asymmetry and fluctuations in flow quantities and the flow reversal would not occur in absence of the cells. It is concluded that the flow physics and its physiological consequences are significantly different in micro- versus macrovascular stenosis. PMID:27319318

  12. Cytoplasmic calcium buffers in intact human red cells.

    PubMed Central

    Tiffert, T; Lew, V L

    1997-01-01

    1. Precise knowledge of the cytoplasmic Ca2+ buffering behaviour in intact human red cells is essential for the characterization of their [Ca2+]i-dependent functions. This was investigated by using a refined method and experimental protocols which allowed continuity in the estimates of [Ca2+]i, from nanomolar to millimolar concentrations, in the presence and absence of external Ca2+ chelators. 2. The study was carried out in human red cells whose plasma membrane Ca2+ pump was inhibited either by depleting the cells of ATP or by adding vanadate to the cell suspension. Cytoplasmic Ca2+ buffering was analysed from plots of total cell calcium content vs. ionized cytoplasmic Ca2+ concentration ([CaT]i vs. [Ca2+]i) obtained from measurements of the equilibrium distribution of 45Ca2+ at different external Ca2+ concentrations ([Ca2+]o), in conditions known to clamp cell volume and pH. The equilibrium distribution of 45Ca2+ was induced by the divalent cation ionophore A23187. 3. The results showed the following. (i) The known red cell Ca2+ buffer represented by alpha, with a large capacity and low Ca2+ affinity, was the main cytoplasmic Ca2+ binding agent. (ii) The value of alpha was remarkably constant; the means for each of four donors ranged from 0.33 to 0.35, with a combined value of all independent measurements of 0.34 +/- 0.01 (mean +/- S.E.M., n = 16). This contrasts with the variability previously reported. (iii) There was an additional Ca2+ buffering complex with a low capacity (approximately 80 micromol (340 g Hb)(-1)) and intermediate Ca2+ affinity (apparent dissociation constant, K(D,app) approximately 4-50 microM) whose possible identity is discussed. (iv) The cell content of putative Ca2+ buffers with submicromolar Ca2+ dissociation constants was below the detection limit of the methods used here (less than 2 micromol (340 g Hb)(-1)). 4. Vanadate (1 mM) inhibited the Vmax of the Ca2+ pump in inosine-fed cells by 99.7%. The cytoplasmic Ca2+ buffering behaviour

  13. Changes in En(a-) human red blood cell membranes during in vivo ageing.

    PubMed

    Shinozuka, T; Miyata, Y; Takei, S; Yoshida, R; Ogamo, A; Nakagawa, Y; Kuroda, N; Yanagida, J

    1996-01-01

    The human red blood cells with phenotype En(a-) were characterized by the lack of MN antigens. The red blood cells with phenotype En(a-) which were found in a Japanese family were tested to clarify the changes in membrane surfaces of the red blood cells during in vivo ageing. The contents of sialic acid, glucose, mannose, galactose, fucose, N-acetylglucosamine and N-acetylgalactosamine of the red blood cell membranes obtained from the old red blood cells with phenotype En(a-) were significantly lower than those of the young red blood cell membranes. Neither the young nor the old red blood cells with phenotype En(a-) showed the agglutination with Arachis hypogaea (PNA) which was capable of binding to T agglutinogen. It is presumed that En(a-) red blood cells are not exposed to sialidase in vivo. In comparison with the young En(a-) red blood cell membranes, the number and the distribution density of lectin receptor sites on the old ones for Limulus polyphemus (LPA), Canavalia ensiformis (Con A), Triticum vulgaris (WGA) and Bauhinia purpurea (BPA) were significantly lower. It is thought that En(a-) red blood cell ageing is accompanied by elimination of some sialoglycoconjugates which have affinity for LPA, Con A, WGA and BPA, whereas En(a-) red blood cells lack glycophorin A. PMID:8866734

  14. Metabolic pathways that correlate with post-transfusion circulation of stored murine red blood cells.

    PubMed

    de Wolski, Karen; Fu, Xiaoyoun; Dumont, Larry J; Roback, John D; Waterman, Hayley; Odem-Davis, Katherine; Howie, Heather L; Zimring, James C

    2016-05-01

    Transfusion of red blood cells is a very common inpatient procedure, with more than 1 in 70 people in the USA receiving a red blood cell transfusion annually. However, stored red blood cells are a non-uniform product, based upon donor-to-donor variation in red blood cell storage biology. While thousands of biological parameters change in red blood cells over storage, it has remained unclear which changes correlate with function of the red blood cells, as opposed to being co-incidental changes. In the current report, a murine model of red blood cell storage/transfusion is applied across 13 genetically distinct mouse strains and combined with high resolution metabolomics to identify metabolic changes that correlated with red blood cell circulation post storage. Oxidation in general, and peroxidation of lipids in particular, emerged as changes that correlated with extreme statistical significance, including generation of dicarboxylic acids and monohydroxy fatty acids. In addition, differences in anti-oxidant pathways known to regulate oxidative stress on lipid membranes were identified. Finally, metabolites were identified that differed at the time the blood was harvested, and predict how the red blood cells perform after storage, allowing the potential to screen donors at time of collection. Together, these findings map out a new landscape in understanding metabolic changes during red blood cell storage as they relate to red blood cell circulation. PMID:26921359

  15. Membrane stress increases cation permeability in red cells.

    PubMed

    Johnson, R M

    1994-11-01

    The human red cell is known to increase its cation permeability when deformed by mechanical forces. Light-scattering measurements were used to quantitate the cell deformation, as ellipticity under shear. Permeability to sodium and potassium was not proportional to the cell deformation. An ellipticity of 0.75 was required to increase the permeability of the membrane to cations, and flux thereafter increased rapidly as the limits of cell extension were reached. Induction of membrane curvature by chemical agents also did not increase cation permeability. These results indicate that membrane deformation per se does not increase permeability, and that membrane tension is the effector for increased cation permeability. This may be relevant to some cation permeabilities observed by patch clamping. PMID:7858123

  16. Red cell glycolytic enzyme disorders caused by mutations: an update.

    PubMed

    Climent, Fernando; Roset, Feliu; Repiso, Ada; Pérez de la Ossa, Pablo

    2009-06-01

    Glycolysis is one of the principle pathways of ATP generation in cells and is present in all cell tissues; in erythrocytes, glycolysis is the only pathway for ATP synthesis since mature red cells lack the internal structures necessary to produce the energy vital for life. Red cell deficiencies have been detected in all erythrocyte glycolytic pathways, although their frequencies differ owing to diverse causes, such as the affected enzyme and severity of clinical manifestations. The number of enzyme deficiencies known is endless. The most frequent glycolysis abnormality is pyruvate kinase deficiency, since around 500 cases are known, the first of which was reported in 1961. However, only approximately 200 cases were due to mutations. In contrast, only one case of phosphoglycerate mutase BB type mutation, described in 2003, has been detected. Most mutations are located in the coding sequences of genes, while others, missense, deletions, insertions, splice defects, premature stop codons and promoter mutations, are also frequent. Understanding of the crystal structure of enzymes permits molecular modelling studies which, in turn, reveal how mutations can affect enzyme structure and function. PMID:19519368

  17. Deformation of red blood cells using acoustic radiation forces

    PubMed Central

    Mishra, Puja; Hill, Martyn; Glynne-Jones, Peter

    2014-01-01

    Acoustic radiation forces have been used to manipulate cells and bacteria in a number of recent microfluidic applications. The net force on a cell has been subject to careful investigation over a number of decades. We demonstrate that the radiation forces also act to deform cells. An ultrasonic standing wave field is created in a 0.1 mm glass capillary at a frequency of 7.9 MHz. Using osmotically swollen red-blood cells, we show observable deformations up to an aspect ratio of 1.35, comparable to deformations created by optical tweezing. In contrast to optical technologies, ultrasonic devices are potentially capable of deforming thousands of cells simultaneously. We create a finite element model that includes both the acoustic environment of the cell, and a model of the cell membrane subject to forces resulting from the non-linear aspects of the acoustic field. The model is found to give reasonable agreement with the experimental results, and shows that the deformation is the result of variation in an acoustic force that is directed outwards at all points on the cell membrane. We foresee applications in diagnostic devices, and in the possibility of mechanically stimulating cells to promote differentiation and physiological effects. PMID:25379070

  18. Metabolic profiling of hematopoietic stem and progenitor cells during proliferation and differentiation into red blood cells.

    PubMed

    Daud, Hasbullah; Browne, Susan; Al-Majmaie, Rasoul; Murphy, William; Al-Rubeai, Mohamed

    2016-01-25

    An understanding of the metabolic profile of cell proliferation and differentiation should support the optimization of culture conditions for hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and maturation into red blood cells. We have evaluated the key metabolic parameters during each phase of HSPC culture for red blood cell production in serum-supplemented (SS) and serum-free (SF) conditions. A simultaneous decrease in growth rate, total protein content, cell size, and the percentage of cells in the S/G2 phase of cell cycle, as well as an increase in the percentage of cells with a CD71(-)/GpA(+) surface marker profile, indicates HSPC differentiation into red blood cells. Compared with proliferating HSPCs, differentiating HSPCs showed significantly lower glucose and glutamine consumption rates, lactate and ammonia production rates, and amino acid consumption and production rates in both SS and SF conditions. Furthermore, extracellular acidification was associated with late proliferation phase, suggesting a reduced cellular metabolic rate during the transition from proliferation to differentiation. Under both SS and SF conditions, cells demonstrated a high metabolic rate with a mixed metabolism of both glycolysis and oxidative phosphorylation (OXPHOS) in early and late proliferation, an increased dependence on OXPHOS activity during differentiation, and a shift to glycolytic metabolism only during maturation phase. These changes indicate that cell metabolism may have an important impact on the ability of HSPCs to proliferate and differentiate into red blood cells. PMID:26013297

  19. Influence of increased membrane cholesterol on membrane fluidity and cell function in human red blood cells.

    PubMed

    Cooper, R A

    1978-01-01

    Cholesterol and phospholipid are the two major lipids of the red cell membrane. Cholesterol is insoluble in water but is solubilized by phospholipids both in membranes and in plasma lipoproteins. Morever, cholesterol exchanges between membranes and lipoproteins. An equilibrium partition is established based on the amount of cholesterol relative to phospholipid (C/PL) in these two compartments. Increases in the C/PL of red cell membranes have been studied under three conditions: First, spontaneous increases in vivo have been observed in the spur red cells of patients with severe liver disease; second, similar red cell changes in vivo have been induced by the administration of cholesterol-enriched diets to rodents and dogs; third, increases in membrane cholesterol have been induced in vitro by enriching the C/PL of the lipoprotein environment with cholesterol-phospholipid dispersions (liposomes) having a C/PL of greater than 1.0. In each case, there is a close relationship between the C/PL of the plasma environment and the C/PL of the red cell membrane. In vivo, the C/PL mole ratio of red cell membranes ranges from a normal value of 0.09--1.0 to values which approach but do not reach 2.0. In vitro, this ratio approaches 3.0. Cholesterol enrichment of red cell membranes directly influences membrane lipid fluidity, as assessed by the rotational diffusion of hydrophobic fluorescent probes such as diphenyl hexatriene (DPH). A close correlation exists between increases in red cell membrane C/PL and decreases in membrane fluidity over the range of membrane C/PL from 1.0 to 2.0; however, little further change in fluidity occurs when membrane C/PL is increased to 2.0--3.0. Cholesterol enrichment of red cell membranes is associated with the transformation of cell contour to one which is redundant and folded, and this is associated with a decrease in red cell filterability in vitro. Circulation in vivo in the presence of the spleen further modifies cell shape to a spiny

  20. From stem cell to red blood cells in vitro: "the 12 labors of Hercules".

    PubMed

    Douay, Luc

    2010-06-01

    This article describes the research in progress that will permit the large-scale production of human red blood cells from hematopoietic stem cells. It also discusses the current state of this research, suggests the obstacles to be overcome to pass from the laboratory model to clinical practice, and analyzes the possible indications in the medium and long term. The potential interest of pluripotent stem cells as an unlimited source of red blood cells is considered. If it succeeds, this new approach could mark a considerable advance in the field of transfusion. PMID:20513558

  1. Automatic analysis of microscopic images of red blood cell aggregates

    NASA Astrophysics Data System (ADS)

    Menichini, Pablo A.; Larese, Mónica G.; Riquelme, Bibiana D.

    2015-06-01

    Red blood cell aggregation is one of the most important factors in blood viscosity at stasis or at very low rates of flow. The basic structure of aggregates is a linear array of cell commonly termed as rouleaux. Enhanced or abnormal aggregation is seen in clinical conditions, such as diabetes and hypertension, producing alterations in the microcirculation, some of which can be analyzed through the characterization of aggregated cells. Frequently, image processing and analysis for the characterization of RBC aggregation were done manually or semi-automatically using interactive tools. We propose a system that processes images of RBC aggregation and automatically obtains the characterization and quantification of the different types of RBC aggregates. Present technique could be interesting to perform the adaptation as a routine used in hemorheological and Clinical Biochemistry Laboratories because this automatic method is rapid, efficient and economical, and at the same time independent of the user performing the analysis (repeatability of the analysis).

  2. Measurement of red blood cell mechanics during morphological changes

    NASA Astrophysics Data System (ADS)

    Popescu, Gabriel; Park, Yongkeun; Best, Catherine; Dasari, Ramachandra; Feld, Michael; Kuriabova, Tatiana; Henle, Mark; Levine, Alex

    2010-03-01

    The human red blood cell (RBC) membrane, a fluid lipid bilayer tethered to an elastic 2D spectrin network, provides the principal control of the cell's morphology and mechanics. These properties, in turn, influence the ability of RBCs to transport oxygen in circulation. Current mechanical measurements of RBCs rely on external loads. Here we apply a Noncontact optical interferometric technique to quantify the thermal fluctuations of RBC membranes with 3 nm accuracy over a broad range of spatial and temporal frequencies. Combining this technique with a new mathematical model describing RBC membrane undulations, we measure the mechanical changes of RBCs as they undergo a transition from the normal discoid shape to the abnormal echinocyte and spherical shapes. These measurements indicate that, coincident with this morphological transition, there is a significant increase in the membrane's shear and bending moduli. This mechanical transition can alter cell circulation and impede oxygen delivery.

  3. Depletion induced clustering of red blood cells in microchannels

    NASA Astrophysics Data System (ADS)

    Wagner, Christian; Brust, Mathias; Podgorski, Thomas; Coupier, Gwennou

    2012-11-01

    The flow properties of blood are determined by the physical properties of its main constituents, the red blood cells (RBC's). At low shear rates RBC's form aggregates, so called rouleaux. Higher shear rates can break them up and the viscosity of blood shows a shear thinning behavior. The physical origin of the rouleaux formation is not yet fully resolved and there are two competing models available. One predicts that the adhesion is induced by bridging of the plasma (macromolecular) proteins in-between two RBC's. The other is based on the depletion effect and thus predicts the absence of macromolecules in-between the cells of a rouleaux. Recent single cell force measurements by use of an AFM support strongly the depletion model. By varying the concentration of Dextran at different molecular weights we can control the adhesions strength. Measurements at low hematocrit in a microfluidic channel show that the number of size of clusters is determined by the depletion induced adhesion strength.

  4. Transport of diseased red blood cells in the spleen

    NASA Astrophysics Data System (ADS)

    Peng, Zhangli; Pivkin, Igor; Dao, Ming

    2012-11-01

    A major function of the spleen is to remove old and diseased red blood cells (RBCs) with abnormal mechanical properties. We investigated this mechanical filtering mechanism by combining experiments and computational modeling, especially for red blood cells in malaria and sickle cell disease (SCD). First, utilizing a transgenic line for 3D confocal live imaging, in vitro capillary assays and 3D finite element modeling, we extracted the mechanical properties of both the RBC membrane and malaria parasites for different asexual malaria stages. Secondly, using a non-invasive laser interferometric technique, we optically measured the dynamic membrane fluctuations of SCD RBCs. By simulating the membrane fluctuation experiment using the dissipative particle dynamics (DPD) model, we retrieved mechanical properties of SCD RBCs with different shapes. Finally, based on the mechanical properties obtained from these experiments, we simulated the full fluid-structure interaction problem of diseased RBCs passing through endothelial slits in the spleen under different fluid pressure gradients using the DPD model. The effects of the mechanical properties of the lipid bilayer, the cytoskeleton and the parasite on the critical pressure of splenic passage of RBCs were investigated separately. This work is supported by NIH and Singapore-MIT Alliance for Science and Technology (SMART).

  5. Red Fluorescent Carbon Nanoparticle-Based Cell Imaging Probe.

    PubMed

    Ali, Haydar; Bhunia, Susanta Kumar; Dalal, Chumki; Jana, Nikhil R

    2016-04-13

    Fluorescent carbon nanoparticle-based probes with tunable visible emission are biocompatible, environment friendly and most suitable for various biomedical applications. However, synthesis of red fluorescent carbon nanoparticles and their transformation into functional nanoparticles are very challenging. Here we report red fluorescent carbon nanoparticle-based nanobioconjugates of <25 nm hydrodynamic size and their application as fluorescent cell labels. Hydrophobic carbon nanoparticles are synthesized via high temperature colloid-chemical approach and transformed into water-soluble functional nanoparticles via coating with amphiphilic polymer followed by covalent linking with desired biomolecules. Following this approach, carbon nanoparticles are functionalized with polyethylene glycol, primary amine, glucose, arginine, histidine, biotin and folic acid. These functional nanoparticles can be excited with blue/green light (i.e., 400-550 nm) to capture their emission spanning from 550 to 750 nm. Arginine and folic acid functionalized nanoparticles have been demonstrated as fluorescent cell labels where blue and green excitation has been used for imaging of labeled cells. The presented method can be extended for the development of carbon nanoparticle-based other bioimaging probes. PMID:27011336

  6. Vibrational modes of hemoglobin in red blood cells.

    PubMed Central

    Martel, P; Calmettes, P; Hennion, B

    1991-01-01

    Equine red blood cells were washed in saline heavy water (2H2O) to exchange the hydrogen atoms of the non-hemoglobin components with deuterons. This led to novel neutron scattering measurements of protein vibrations within a cellular system and permitted a comparison with inelastic neutron scattering measurements on purified horse hemoglobin, either dry or wetted with 2H2O. As a function of wavevector transfer Q and the frequency transfer v the neutron response typified by the dynamic structure factor S(Q, v) was found to be similar for extracted and cellular hemoglobin at low and high temperatures. At 77 K, in the cells, a peak in S(Q, v) due to the protein was found near 0.7 THz, approximately half the frequency of a strong peak in the aqueous medium. Measurements at higher temperatures (170 and 230 K) indicated similar small shifts downwards in the peak frequencies of both components. At 260 K the low frequency component became predominantly quasielastic, but a significant inelastic component could still be ascribed to the aqueous scattering. Near 295 K the frequency responses of both components were similar and centered near zero. When scattering due to water is taken into account it appears that the protein neutron response in, or out of, red blood cells is little affected by hydration in the low frequency regime where Van der Waals forces are thought to be effective. PMID:1849028

  7. Pure red cell aplasia induced by epoetin zeta.

    PubMed

    Panichi, Vincenzo; Ricchiuti, Guido; Scatena, Alessia; Del Vecchio, Lucia; Locatelli, Francesco

    2016-08-01

    Pure red cell aplasia (PRCA) may develop in patients with chronic kidney disease receiving erythropoiesis-stimulating agents (ESA). We report on a 72-year-old patient who developed hypo-proliferative anaemia unresponsive to ESA following the administration of epoetin zeta subcutaneously for 7 months. On the basis of severe isolated hypoplasia of the erythroid line in the bone marrow and high-titre neutralizing anti-erythropoietin antibodies (Ab), a diagnosis of Ab-mediated PRCA was made. Epoetin zeta was discontinued and the patient was given steroids. This was associated with anaemia recovery. To our knowledge this is the first PRCA case related to epoetin zeta. PMID:27478604

  8. The nature of multiphoton fluorescence from red blood cells

    NASA Astrophysics Data System (ADS)

    Saytashev, Ilyas; Murphy, Michael; Osseiran, Sam; Spence, Dana M.; Evans, Conor L.; Dantus, Marcos

    2016-03-01

    We report on the nature of multiphoton excited fluorescence observed from human erythrocytes (red blood cells RBC's) and their "ghosts" following 800nm sub-15 fs excitation. The detected optical signal is assigned as two-photon excited fluorescence from hemoglobin. Our findings are supported by wavelength-resolved fluorescence lifetime decay measurements using time-correlated single photon counting system from RBC's, their ghosts as well as in vitro samples of various fluorophores including riboflavin, NADH, NAD(P)H, hemoglobin. We find that low-energy and short-duration pulses allow two-photon imaging of RBC's, but longer more intense pulses lead to their destruction.

  9. Pure red cell aplasia induced by epoetin zeta

    PubMed Central

    Panichi, Vincenzo; Ricchiuti, Guido; Scatena, Alessia; Del Vecchio, Lucia; Locatelli, Francesco

    2016-01-01

    Pure red cell aplasia (PRCA) may develop in patients with chronic kidney disease receiving erythropoiesis-stimulating agents (ESA). We report on a 72-year-old patient who developed hypo-proliferative anaemia unresponsive to ESA following the administration of epoetin zeta subcutaneously for 7 months. On the basis of severe isolated hypoplasia of the erythroid line in the bone marrow and high-titre neutralizing anti-erythropoietin antibodies (Ab), a diagnosis of Ab-mediated PRCA was made. Epoetin zeta was discontinued and the patient was given steroids. This was associated with anaemia recovery. To our knowledge this is the first PRCA case related to epoetin zeta. PMID:27478604

  10. Cytoskeleton confinement of red blood cell membrane fluctuations

    NASA Astrophysics Data System (ADS)

    Gov, Nir; Zilman, Anton; Safran, Samuel

    2003-03-01

    We analyze theoretically both the static and dynamic fluctuation spectrum of the red-blood cell in a unified manner, using a simple model of the composite membrane. In this model, the two-dimensional spectrin network that forms the cytoskeleton is treated as a rigid shell, located at a fixed, average distance from the lipid bilayer. The cytoskeleton thereby confines both the static and dynamic fluctuations of the lipid bilayer. The predictions of the model account for the wavevector and frequency dependence of the experimental data.

  11. Cytoskeleton Confinement and Tension of Red Blood Cell Membranes

    NASA Astrophysics Data System (ADS)

    Gov, N.; Zilman, A. G.; Safran, S.

    2003-06-01

    We analyze theoretically both the static and dynamic fluctuation spectra of the red blood cell in a unified manner, using a simple model of the composite membrane. In this model, the two-dimensional spectrin network that forms the cytoskeleton is treated as a rigid shell, located at a fixed, average distance from the lipid bilayer. The cytoskeleton thereby confines both the static and dynamic fluctuations of the lipid bilayer. The sparse connections of the cytoskeleton and bilayer induce a surface tension, for wavelengths larger than the bilayer persistence length. The predictions of the model give a consistent account for both the wave vector and frequency dependence of the experimental data.

  12. Red blood cell orientation in orbit C = 0.

    PubMed Central

    Bitbol, M

    1986-01-01

    Two modes of behavior of single human red cells in a shear field have been described. It is known that in low viscosity media and at shear rates less than 20 s-1, the cells rotate with a periodically varying angular velocity, in accord with the theory of Jeffery (1922) for oblate spheroids. In media of viscosity greater than approximately 5 mPa s and sufficiently high shear rates, the cells align themselves at a constant angle to the direction of flow with the membrane undergoing tank-tread motion. Also, in low viscosity media, as the shear rate is increased, more and more cells lie in the plane of shear, undergoing spin with their axes of symmetry aligned with the vorticity axis of the shear field in an orbit "C = 0" (Goldsmith and Marlow, 1972). We have explored this latter phenomenon using two experimental methods. First, the erythrocytes were observed in the rheoscope and their diameters measured. Forward light scattering patterns were correlated with the red cell orientation mode. Light flux variations after flow onset or stop were measured, and the characteristic times of erythrocyte orientation and disorientation were assessed. The characteristic time of erythrocyte orientation in Orbit C = 0 is proportional to the inverse of the shear rate. The corresponding coefficient of proportionality depends on the suspending medium viscosity eta o. The disorientation time tau D, after flow has been stopped, is such that the ratio tau D/eta o is independent of the initial applied shear stress. However, tau D is much shorter than one would expect if pure Brownian motion were involved. The proportion of erythrocytes in orbit C = 0 was also measured. It was found that this proportion is a function of both the shear rate and eta o. At low values of eta o, the proportion increases with increasing shear rate and then reaches a plateau. For higher values of eta o (5 to 10 mPa s), the proportion of RBC in orbit C = 0 is a decreasing function of the shear stress. A critical

  13. Molecular Detection and Discrimination of Blueberry Red Ringspot Virus Strains Causing Disease in Cultivated Blueberry and Cranberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blueberry red ringspot virus (BRRV) causes red ringspots to appear on blueberry stems, leaves and ripening fruit. Published reports of the virus in cultivated blueberry have thus far been limited to highbush (V. corymbosum). A disease with similar symptoms occurs in cranberry (V. macrocarpon), but i...

  14. [Red Blood Cells Raman Spectroscopy Comparison of Type Two Diabetes Patients and Rats].

    PubMed

    Wang, Lei; Liu, Gui-dong; Mu, Xin; Xiao, Hong-bin; Qi, Chao; Zhang, Si-qi; Niu Wen-ying; Jiang, Guang-kun; Feng, Yue-nan; Bian, Jing-qi

    2015-10-01

    By using confocal Raman spectroscopy, Raman spectra were measured in normal rat red blood cells, normal human red blood cells, STZ induced diabetetic rats red blood cells, Alloxan induced diabetetic rats red blood cells and human type 2 diabetes red blood cells. Then principal component analysis (PCA) with support vector machine (SVM) classifier was used for data analysis, and then the distance between classes was used to judge the degree of close to two kinds of rat model with type 2 diabetes. The results found significant differences in the Raman spectra of red blood cell in diabetic and normal red blood cells. To diabetic red blood cells, the peak in the amide VI C=O deformation vibration band is obvious, and amide V N-H deformation vibration band spectral lines appear deviation. Belong to phospholipid fatty acyl C-C skeleton, the 1 130 cm(-1) spectral line is enhanced and the 1 088 cm(-1) spectral line is abated, which show diabetes red cell membrane permeability increased. Raman spectra of PCA combined with SVM can well separate 5 types of red blood cells. Classifier test results show that the classification accuracy is up to 100%. Through the class distance between the two induced method and human type 2 diabetes, it is found that STZ induced model is more close to human type 2 diabetes. In conclusion, Raman spectroscopy can be used for diagnosis of diabetes and rats STZ induced diabetes method is closer to human type 2 diabetes. PMID:26904817

  15. Bio-inspired Cryo-ink Preserves Red Blood Cell Phenotype and Function during Nanoliter Vitrification

    PubMed Central

    Assal, Rami El; Guven, Sinan; Gurkan, Umut Atakan; Gozen, Irep; Shafiee, Hadi; Dalbeyber, Sedef; Abdalla, Noor; Thomas, Gawain; Fuld, Wendy; Illigens, Ben M.W.; Estanislau, Jessica; Khoory, Joseph; Kaufman, Richard; Zylberberg, Claudia; Lindeman, Neal; Wen, Qi; Ghiran, Ionita; Demirci, Utkan

    2014-01-01

    Current red blood cell cryopreservation methods utilize bulk volumes, causing cryo-injury of cells, which results in irreversible disruption of cell morphology, mechanics, and function. An innovative approach to preserve human red blood cell morphology, mechanics, and function following vitrification in nanoliter volumes is developed using a novel cryo-ink integrated with a bio-printing approach. PMID:25047246

  16. A system for counting fetal and maternal red blood cells.

    PubMed

    Ge, Ji; Gong, Zheng; Chen, Jun; Liu, Jun; Nguyen, John; Yang, Zongyi; Wang, Chen; Sun, Yu

    2014-12-01

    The Kleihauer-Betke (KB) test is the standard method for quantitating fetal-maternal hemorrhage in maternal care. In hospitals, the KB test is performed by a certified technologist to count a minimum of 2000 fetal and maternal red blood cells (RBCs) on a blood smear. Manual counting suffers from inherent inconsistency and unreliability. This paper describes a system for automated counting and distinguishing fetal and maternal RBCs on clinical KB slides. A custom-adapted hardware platform is used for KB slide scanning and image capturing. Spatial-color pixel classification with spectral clustering is proposed to separate overlapping cells. Optimal clustering number and total cell number are obtained through maximizing cluster validity index. To accurately identify fetal RBCs from maternal RBCs, multiple features including cell size, roundness, gradient, and saturation difference between cell and whole slide are used in supervised learning to generate feature vectors, to tackle cell color, shape, and contrast variations across clinical KB slides. The results show that the automated system is capable of completing the counting of over 60,000 cells (versus ∼2000 by technologists) within 5 min (versus ∼15 min by technologists). The throughput is improved by approximately 90 times compared to manual reading by technologists. The counting results are highly accurate and correlate strongly with those from benchmarking flow cytometry measurement. PMID:24879644

  17. The Case for Absolute Ligand Discrimination: Modeling Information Processing and Decision by Immune T Cells

    NASA Astrophysics Data System (ADS)

    François, Paul; Altan-Bonnet, Grégoire

    2016-03-01

    Some cells have to take decision based on the quality of surroundings ligands, almost irrespective of their quantity, a problem we name "absolute discrimination". An example of absolute discrimination is recognition of not-self by immune T Cells. We show how the problem of absolute discrimination can be solved by a process called "adaptive sorting". We review several implementations of adaptive sorting, as well as its generic properties such as antagonism. We show how kinetic proofreading with negative feedback implement an approximate version of adaptive sorting in the immune context. Finally, we revisit the decision problem at the cell population level, showing how phenotypic variability and feedbacks between population and single cells are crucial for proper decision.

  18. Red blood cell distribution width and cardiovascular diseases

    PubMed Central

    Danese, Elisa; Lippi, Giuseppe

    2015-01-01

    Background The red blood cell distribution width (RDW) is a rather simple measure of red blood cell (RBC) size heterogeneity (i.e., anisocytosis), which is easily calculated by dividing the standard deviation (SD) of erythrocyte volumes for the mean corpuscular volume (MCV). Emerging evidence suggests that, besides RBC abnormalities, many human disorders may be frequently associated with a high degree of anisocytosis. Methods In this narrative review, we analyzed the current scientific literature about the putative role and the potential epidemiologic association between RDW and cardiovascular diseases. The findings of the most representative epidemiological studies were summarized and discussed. Results Overall, considerable and convincing evidence has been brought that an increased RDW value is associated with acute coronary syndrome (ACS) [including acute myocardial infarction (AMI)], ischemic cerebrovascular disease (including stroke), peripheral artery disease (PAD), as well as with atrial fibrillation (AF), heart failure (HF) and hypertension. Higher anisocytosis also significantly and independently predicts adverse outcomes in patients with these conditions. Conclusions Although the role of anisocytosis in the pathogenesis of cardiovascular diseases remains uncertain, the considerable evidence available so far suggests that the clinical use of RDW may be broadened beyond the conventional boundaries of erythrocyte disorders, in particular for assisting the diagnosis and prognostication of patients with ACS, ischemic cerebrovascular disease, PAD, HF and AF. PMID:26623117

  19. Existence of a Flat Phase in Red Cell Membrane Skeletons

    NASA Astrophysics Data System (ADS)

    Schmidt, Christoph F.; Svoboda, Karel; Lei, Ning; Petsche, Irena B.; Berman, Lonny E.; Safinya, Cyrus R.; Grest, Gary S.

    1993-02-01

    Biomolecular membranes display rich statistical mechanical behavior. They are classified as liquid in the absence of shear elasticity in the plane of the membrane and tethered (solid) when the neighboring molecules or subunits are connected and the membranes exhibit solid-like elastic behavior in the plane of the membrane. The spectrin skeleton of red blood cells was studied as a model tethered membrane. The static structure factor of the skeletons, measured by small-angle x-ray and light scattering, was fitted with a structure factor predicted with a model calculation. The model describes tethered membrane sheets with free edges in a flat phase, which is a locally rough but globally flat membrane configuration. The fit was good for large scattering vectors. The membrane roughness exponent, zeta, defined through h propto L^zeta, where h is the average amplitude of out-of-plane fluctuations and L is the linear membrane dimension, was determined to be 0.65 ± 0.10. Computer simulations of model red blood cell skeletons also showed this flat phase. The value for the roughness exponent, which was determined from the scaling properties of membranes of different sizes, was consistent with that from the experiments.

  20. Interaction of injectable neurotropic drugs with the red cell membrane.

    PubMed

    Reinhart, Walter H; Lubszky, Szabina; Thöny, Sandra; Schulzki, Thomas

    2014-10-01

    The normal red blood cell (RBC) shape is a biconcave discocyte. An intercalation of a drug in the outer half of the membrane lipid bilayer leads to echinocytosis, an intercalation in the inner half to stomatocytosis. We have used the shape transforming capacity of RBCs as a model to analyse the membrane interaction potential of various neurotropic drugs. Chlorpromazine, clomipramine, citalopram, clonazepam, and diazepam induced a reversible stomatocytosis, phenytoin induced echinocytosis, while the anticonvulsants levetiracetam, valproic acid and phenobarbital had no effect. This diversity of RBC shape transformations suggests that the pharmacological action is not linked to the membrane interaction. We conclude that this simple RBC shape transformation assay could be a useful tool to screen for potential drug interactions with cell membranes. PMID:24997296

  1. Anisotropic light scattering of individual sickle red blood cells

    NASA Astrophysics Data System (ADS)

    Kim, Youngchan; Higgins, John M.; Dasari, Ramachandra R.; Suresh, Subra; Park, YongKeun

    2012-04-01

    We present the anisotropic light scattering of individual red blood cells (RBCs) from a patient with sickle cell disease (SCD). To measure light scattering spectra along two independent axes of elongated-shaped sickle RBCs with arbitrary orientation, we introduce the anisotropic Fourier transform light scattering (aFTLS) technique and measured both the static and dynamic anisotropic light scattering. We observed strong anisotropy in light scattering patterns of elongated-shaped sickle RBCs along its major axes using static aFTLS. Dynamic aFTLS analysis reveals the significantly altered biophysical properties in individual sickle RBCs. These results provide evidence that effective viscosity and elasticity of sickle RBCs are significantly different from those of the healthy RBCs.

  2. Measurement of the nonlinear elasticity of red blood cell membranes

    NASA Astrophysics Data System (ADS)

    Park, Yongkeun; Best, Catherine A.; Kuriabova, Tatiana; Henle, Mark L.; Feld, Michael S.; Levine, Alex J.; Popescu, Gabriel

    2011-05-01

    The membranes of human red blood cells (RBCs) are a composite of a fluid lipid bilayer and a triangular network of semiflexible filaments (spectrin). We perform cellular microrheology using the dynamic membrane fluctuations of the RBCs to extract the elastic moduli of this composite membrane. By applying known osmotic stresses, we measure the changes in the elastic constants under imposed strain and thereby determine the nonlinear elastic properties of the membrane. We find that the elastic nonlinearities of the shear modulus in tensed RBC membranes can be well understood in terms of a simple wormlike chain model. Our results show that the elasticity of the spectrin network can mostly account for the area compression modulus at physiological osmolality, suggesting that the lipid bilayer has significant excess area. As the cell swells, the elastic contribution from the now tensed lipid membrane becomes dominant.

  3. Red Blood Cells Motion in a Glass Microchannel

    NASA Astrophysics Data System (ADS)

    Pinho, Diana; Pereira, Ana I.; Lima, Rui

    2010-09-01

    The motion of the red blood cells (RBCs) flowing in microvessels and microchannels depend on several effects, such as hematocrit (Hct), geometry, and temperature. According to our knowledge, the effect of the temperature on RBC motion was never investigated at a microscale level. Hence, the aim of the present work is to determine the effect of the temperature on the RBC's trajectories and to investigate the best approximation of the trajectories through a nonlinear optimization. In vitro human blood was pumped through a 100 μm circular microchannel and by using a confocal micro-PTV system the RBC's trajectories were measured at different temperatures, i.e., 25° C and 37° C. In this study we measured the motion of forty cells flowing in the middle of the microchannel and applied different functions to approximate its behavior.

  4. Stretching and relaxation of malaria-infected red blood cells.

    PubMed

    Ye, Ting; Phan-Thien, Nhan; Khoo, Boo Cheong; Lim, Chwee Teck

    2013-09-01

    The invasion of red blood cells (RBCs) by malaria parasites is a complex dynamic process, in which the infected RBCs gradually lose their deformability and their ability to recover their original shape is greatly reduced with the maturation of the parasites. In this work, we developed two types of cell model, one with an included parasite, and the other without an included parasite. The former is a representation of real malaria-infected RBCs, in which the parasite is treated as a rigid body. In the latter, where the parasite is absent, the membrane modulus and viscosity are elevated so as to produce the same features present in the parasite model. In both cases, the cell membrane is modeled as a viscoelastic triangular network connected by wormlike chains. We studied the transient behaviors of stretching deformation and shape relaxation of malaria-infected RBCs based on these two models and found that both models can generate results in agreement with those of previously published studies. With the parasite maturation, the shape deformation becomes smaller and smaller due to increasing cell rigidity, whereas the shape relaxation time becomes longer and longer due to the cell's reduced ability to recover its original shape. PMID:24010653

  5. IMAGING RED BLOOD CELL DYNAMICS BY QUANTITATIVE PHASE MICROSCOPY

    PubMed Central

    Popescu, Gabriel; Park, YoungKeun; Choi, Wonshik; Dasari, Ramachandra R.; Feld, Michael S.; Badizadegan, Kamran

    2008-01-01

    Red blood cells (RBCs) play a crucial role in health and disease, and structural and mechanical abnormalities of these cells have been associated with important disorders such as Sickle cell disease and hereditary cytoskeletal abnormalities. Although several experimental methods exist for analysis of RBC mechanical properties, optical methods stand out as they enable collecting mechanical and dynamic data from live cells without physical contact and without the need for exogenous contrast agents. In this report, we present quantitative phase microscopy techniques that enable imaging RBC membrane fluctuations with nanometer sensitivity at arbitrary time scales from milliseconds to hours. We further provide a theoretical framework for extraction of membrane mechanical and dynamical properties using time series of quantitative phase images. Finally, we present an experimental approach to extend quantitative phase imaging to 3-dimensional space using tomographic methods. By providing non-invasive methods for imaging mechanics of live cells, these novel techniques provide an opportunity for high-throughput analysis and study of RBC mechanical properties in health and disease. PMID:18387320

  6. Measurement of interaction forces between red blood cells in aggregates by optical tweezers

    SciTech Connect

    Maklygin, A Yu; Priezzhev, A V; Karmenian, A; Nikitin, Sergei Yu; Obolenskii, I S; Lugovtsov, Andrei E; Kisun Li

    2012-06-30

    We have fabricated double-beam optical tweezers and demonstrated the possibility of their use for measuring the interaction forces between red blood cells (erythrocytes). It has been established experimentally that prolonged trapping of red blood cells in a tightly focused laser beam does not cause any visible changes in their shape or size. We have measured the interaction between red blood cells in the aggregate, deformed by optical tweezers.

  7. Research opportunities in loss of red blood cell mass in space flight

    NASA Technical Reports Server (NTRS)

    Talbot, J. M.; Fisher, K. D.

    1985-01-01

    Decreases of red blood cell mass and plasma volume have been observed consistently following manned space flights. Losses of red cell mass by United States astronauts have averaged 10 to 15% (range: 2 to 21%). Based on postflight estimates of total hemoglobin, Soviet cosmonauts engaged in space missions lasting from 1 to 7 months have exhibited somewhat greater losses. Restoration of red cell mass requires from 4 to 6 weeks following return to Earth, regardless of the duration of space flight.

  8. Measuring skewness of red blood cell deformability distribution by laser ektacytometry

    SciTech Connect

    Nikitin, S Yu; Priezzhev, A V; Lugovtsov, A E; Ustinov, V D

    2014-08-31

    An algorithm is proposed for measuring the parameters of red blood cell deformability distribution based on laser diffractometry of red blood cells in shear flow (ektacytometry). The algorithm is tested on specially prepared samples of rat blood. In these experiments we succeeded in measuring the mean deformability, deformability variance and skewness of red blood cell deformability distribution with errors of 10%, 15% and 35%, respectively. (laser biophotonics)

  9. Automated counting of morphologically normal red blood cells by using digital holographic microscopy and statistical methods

    NASA Astrophysics Data System (ADS)

    Moon, Inkyu; Yi, Faliu

    2015-09-01

    In this paper we overview a method to automatically count morphologically normal red blood cells (RBCs) by using off-axis digital holographic microscopy and statistical methods. Three kinds of RBC are used as training and testing data. All of the RBC phase images are obtained with digital holographic microscopy (DHM) that is robust to transparent or semitransparent biological cells. For the determination of morphologically normal RBCs, the RBC's phase images are first segmented with marker-controlled watershed transform algorithm. Multiple features are extracted from the segmented cells. Moreover, the statistical method of Hotelling's T-square test is conducted to show that the 3D features from 3D imaging method can improve the discrimination performance for counting of normal shapes of RBCs. Finally, the classifier is designed by using statistical Bayesian algorithm and the misclassification rates are measured with leave-one-out technique. Experimental results show the feasibility of the classification method for calculating the percentage of each typical normal RBC shape.

  10. Hyperemic peripheral red marrow in a patient with sickle cell anemia demonstrated on Tc-99m labeled red blood cell venography

    SciTech Connect

    Heiden, R.A.; Locko, R.C.; Stent, T.R. )

    1991-03-01

    A 25-year-old gravid woman, homozygous for sickle cell anemia, with a history of recent deep venous thrombosis, was examined using Tc-99m labeled red blood cell venography for recurrent thrombosis. Although negative for thrombus, the study presented an unusual incidental finding: the patient's peripheral bone marrow was hyperemic in a distribution consistent with peripheral red bone marrow expansion. Such a pattern has not been documented before using this technique. This report supports other literature that has demonstrated hyperemia of peripheral red bone marrow in other hemolytic anemias. This finding may ultimately define an additional role of scintigraphy in assessing the pathophysiologic status of the sickle cell patient.

  11. Thyroid hormone stimulation in vitro of red blood cell Ca2+-ATPase activity: interspecies variation.

    PubMed

    Davis, F B; Kite, J H; Davis, P J; Blas, S D

    1982-01-01

    In vitro susceptibility to thyroid hormone stimulation of membrane-associated Ca2+-ATPase activity has been examined in red blood cells from rat, rabbit, dog, monkey, and man. Monkey and human red cell Ca2+-ATPase activities responded comparably to 10(-10)M T4 or T3. Basal and thyroid hormone-stimulated Ca2+-ATPase activity in rabbit erythrocytes was four-fold higher than in primate red cells. Rat and dog red cell Ca2+-ATPase did not respond to iodothyronines in vitro. PMID:6459228

  12. Do Additional Bands (coastal, NIR-2, Red-Edge and Yellow) in WORLDVIEW-2 Multispectral Imagery Improve Discrimination of AN Invasive Tussock, Buffel Grass (cenchrus Ciliaris)?

    NASA Astrophysics Data System (ADS)

    Marshall, V.; Lewis, M.; Ostendorf, B.

    2012-07-01

    Our goals is to determine if Worldview-2 8-band multispectral imagery can be used to discriminate an invasive grass species namely, Buffel grass (Cenchrus ciliaris) in the subtropical arid parts of central Australia and whether it offers a tangible improvement on 4-band (visible and near infra red) multispectral imagery. A Worldview-2 scene was acquired for a 10*10km area just west of Alice Springs in central Australia following heavy rains of early Summer. Mixture Tuned Matched Filtering was used to classify the image. Target and background spectra were selected in the field and extracted from the image. Linear discriminate analysis (LDA) was used to examine the spectral separability of each group of the target/ background spectra. The importance of the additional spectral bands on the image classification was assessed by running LDA for both 8 and 4 bands (red, green, blue and NIR). LDA did not indicate improved separability between groups when additional spectral bands were applied. Preliminary classification results indicate that Buffel grass (Cenchrus ciliaris) is detected with an omission error 44%, commission error of 11.8% and overall accuracy of 59.5%. We were surprised that the additional spectral bands did not improve spectral separability and in part attribute this to the high degree of variance we observed within groups of spectra, which was particularly observable in the NIR2 and Yellow bands. The analyses may be significantly improved by acquiring imagery following the first big rains at the end of the dry season. At this time, phonological differences between our focal species and the surrounding native vegetation should be maximised. We suspect that Worldview-2 will offer even greater potential for the discrimination of Buffel grass under these conditions, being able to fully utilise the yellow-band in particular.

  13. Minimal RED cell pairs markedly improve electrode kinetics and power production in microbial reverse electrodialysis cells.

    PubMed

    Cusick, Roland D; Hatzell, Marta; Zhang, Fang; Logan, Bruce E

    2013-12-17

    Power production from microbial reverse electrodialysis cell (MRC) electrodes is substantially improved compared to microbial fuel cells (MFCs) by using ammonium bicarbonate (AmB) solutions in multiple RED cell pair stacks and the cathode chamber. Reducing the number of RED membranes pairs while maintaining enhanced electrode performance could help to reduce capital costs. We show here that using only a single RED cell pair (CP), created by operating the cathode in concentrated AmB, dramatically increased power production normalized to cathode area from both acetate (Acetate: from 0.9 to 3.1 W/m(2)-cat) and wastewater (WW: 0.3 to 1.7 W/m(2)), by reducing solution and charge transfer resistances at the cathode. A second RED cell pair increased RED stack potential and reduced anode charge transfer resistance, further increasing power production (Acetate: 4.2 W/m(2); WW: 1.9 W/m(2)). By maintaining near optimal electrode power production with fewer membranes, power densities normalized to total membrane area for the 1-CP (Acetate: 3.1 W/m(2)-mem; WW: 1.7 W/m(2)) and 2-CP (Acetate: 1.3 W/m(2)-mem; WW: 0.6 W/m(2)) reactors were much higher than previous MRCs (0.3-0.5 W/m(2)-mem with acetate). While operating at peak power, the rate of wastewater COD removal, normalized to reactor volume, was 30-50 times higher in 1-CP and 2-CP MRCs than that in a single chamber MFC. These findings show that even a single cell pair AmB RED stack can significantly enhance electrical power production and wastewater treatment. PMID:24224718

  14. Modeling of Red Blood Cells and Related Spleen Function

    NASA Astrophysics Data System (ADS)

    Peng, Zhangli; Pivkin, Igor; Dao, Ming

    2011-11-01

    A key function of the spleen is to clear red blood cells (RBCs) with abnormal mechanical properties from the circulation. These abnormal mechanical properties may be due to RBC aging or RBC diseases, e.g., malaria and sickle cell anemia. Specifically, 10% of RBCs passing through the spleen are forced to squeeze into the narrow slits between the endothelial cells, and stiffer cells which get stuck are killed and digested by macrophages. To investigate this important physiological process, we employ three different approaches to study RBCs passage through these small slits, including analytical theory, Dissipative Particle Dynamics (DPD) simulation and Multiscale Finite Element Method (MS-FEM). By applying the analytical theory, we estimate the critical limiting geometries RBCs can pass. By using the DPD method, we study the full fluid-structure interaction problem, and compute RBC deformation under different pressure gradients. By employing the MS-FEM approach, we model the lipid bilayer and the cytoskeleton as two distinct layers, and focus on the cytoskeleton deformation and the bilayer-skeleton interaction force at the molecular level. Finally the results of these three approaches are compared to each other and correlated to the experimental observations.

  15. Immunoregulatory function of neonatal nucleated red blood cells in humans.

    PubMed

    Cui, Lili; Takada, Hidetoshi; Takimoto, Tomohito; Fujiyoshi, Junko; Ishimura, Masataka; Hara, Toshiro

    2016-08-01

    We found that human cord blood nucleated red blood cells (NRBCs) have a regulatory function in the innate immune reaction. These cells suppressed the production of inflammatory cytokines including TNF-α and IL-1β from monocytes in response to lipopolysaccharide (LPS). The NRBCs exerted their regulatory function even without cell-to-cell contact with the monocytes. However, IL-10 production from the monocytes by LPS stimulation in the presence of NRBCs was higher than that from LPS-stimulated monocytes cultured in the absence of NRBCs. Addition of an anti-IL-10 receptor blocking antibody restored the inflammatory cytokine production from the monocytes, suggesting that the functional change of the monocytes caused by the interaction with NRBCs was mediated by the increased IL-10 production. A whole-genome microarray analysis revealed that the monocytes expressed increased amounts of IL-10 superfamily genes after interacting with NRBCs. IL-19, which is a member of the IL-10 superfamily, enhanced IL-10 production from the monocytes, which suggested a cooperative role of the IL-10 superfamily in the suppression of inflammatory cytokine production from monocytes. Arginase, which was reported to play an important role in the suppressive function of NRBCs in mice monocytes, was found to have no significant role in human monocytes. The NRBCs seem to have a regulatory role through the induction of IL-10/IL-19 production by monocytes to suppress a vigorous innate immune reaction, which can be harmful to fetuses. PMID:27117669

  16. Dynamic deformability of sickle red blood cells in microphysiological flow

    PubMed Central

    Alapan, Y.; Matsuyama, Y.; Little, J. A.; Gurkan, U. A.

    2016-01-01

    In sickle cell disease (SCD), hemoglobin molecules polymerize intracellularly and lead to a cascade of events resulting in decreased deformability and increased adhesion of red blood cells (RBCs). Decreased deformability and increased adhesion of sickle RBCs lead to blood vessel occlusion (vaso-occlusion) in SCD patients. Here, we present a microfluidic approach integrated with a cell dimensioning algorithm to analyze dynamic deformability of adhered RBC at the single-cell level in controlled microphysiological flow. We measured and compared dynamic deformability and adhesion of healthy hemoglobin A (HbA) and homozygous sickle hemoglobin (HbS) containing RBCs in blood samples obtained from 24 subjects. We introduce a new parameter to assess deformability of RBCs: the dynamic deformability index (DDI), which is defined as the time-dependent change of the cell’s aspect ratio in response to fluid flow shear stress. Our results show that DDI of HbS-containing RBCs were significantly lower compared to that of HbA-containing RBCs. Moreover, we observed subpopulations of HbS containing RBCs in terms of their dynamic deformability characteristics: deformable and non-deformable RBCs. Then, we tested blood samples from SCD patients and analyzed RBC adhesion and deformability at physiological and above physiological flow shear stresses. We observed significantly greater number of adhered non-deformable sickle RBCs than deformable sickle RBCs at flow shear stresses well above the physiological range, suggesting an interplay between dynamic deformability and increased adhesion of RBCs in vaso-occlusive events. PMID:27437432

  17. A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

    PubMed Central

    Müller, Konrad; Engesser, Raphael; Metzger, Stéphanie; Schulz, Simon; Kämpf, Michael M.; Busacker, Moritz; Steinberg, Thorsten; Tomakidi, Pascal; Ehrbar, Martin; Nagy, Ferenc; Timmer, Jens; Zubriggen, Matias D.; Weber, Wilfried

    2013-01-01

    Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system’s performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organisms. PMID:23355611

  18. P2X and P2Y receptor signaling in red blood cells

    PubMed Central

    Sluyter, Ronald

    2015-01-01

    Purinergic signaling involves the activation of cell surface P1 and P2 receptors by extracellular nucleosides and nucleotides such as adenosine and adenosine triphosphate (ATP), respectively. P2 receptors comprise P2X and P2Y receptors, and have well-established roles in leukocyte and platelet biology. Emerging evidence indicates important roles for these receptors in red blood cells. P2 receptor activation stimulates a number of signaling pathways in progenitor red blood cells resulting in microparticle release, reactive oxygen species formation, and apoptosis. Likewise, activation of P2 receptors in mature red blood cells stimulates signaling pathways mediating volume regulation, eicosanoid release, phosphatidylserine exposure, hemolysis, impaired ATP release, and susceptibility or resistance to infection. This review summarizes the distribution of P2 receptors in red blood cells, and outlines the functions of P2 receptor signaling in these cells and its implications in red blood cell biology. PMID:26579528

  19. Bacterial glycosidases for the production of universal red blood cells.

    PubMed

    Liu, Qiyong P; Sulzenbacher, Gerlind; Yuan, Huaiping; Bennett, Eric P; Pietz, Greg; Saunders, Kristen; Spence, Jean; Nudelman, Edward; Levery, Steven B; White, Thayer; Neveu, John M; Lane, William S; Bourne, Yves; Olsson, Martin L; Henrissat, Bernard; Clausen, Henrik

    2007-04-01

    Enzymatic removal of blood group ABO antigens to develop universal red blood cells (RBCs) was a pioneering vision originally proposed more than 25 years ago. Although the feasibility of this approach was demonstrated in clinical trials for group B RBCs, a major obstacle in translating this technology to clinical practice has been the lack of efficient glycosidase enzymes. Here we report two bacterial glycosidase gene families that provide enzymes capable of efficient removal of A and B antigens at neutral pH with low consumption of recombinant enzymes. The crystal structure of a member of the alpha-N-acetylgalactosaminidase family reveals an unusual catalytic mechanism involving NAD+. The enzymatic conversion processes we describe hold promise for achieving the goal of producing universal RBCs, which would improve the blood supply while enhancing the safety of clinical transfusions. PMID:17401360

  20. Mobility Enhancement of Red Blood Cells with Biopolymers

    NASA Astrophysics Data System (ADS)

    Tahara, Daiki; Oikawa, Noriko; Kurita, Rei

    2016-03-01

    Adhesion of red blood cells (RBC) to substrates are one of crucial problems for a blood clot. Here we investigate the mobility of RBC between two glass substrates in saline with polymer systems. We find that RBCs are adhered to the glass substrate with PEG, however the mobility steeply increases with fibrinogen and dextran, which are biopolymers. We also find that the mobility affects an aggregation dynamics of RBCs, which is related with diseases such as influenza, blood clot and so on. The Brownian motion helps to increase probability of contact with each other and to find a more stable condition of the aggregation. Thus the biopolymers play important roles not only for preventing the adhesion but also for the aggregation.

  1. SEM analysis of red blood cells in aged human bloodstains.

    PubMed

    Hortolà, P

    1992-08-01

    Mammal red blood cells (RBC) in bloodstains have been previously detected by light microscopy on stone tools from as early as 100,000 +/- 25,000 years ago. In order to evaluate the degree of morphological preservation of erythrocytes in bloodstains, an accidental human blood smear on white chert and several experimental bloodstains on hard substrates (the same stone-white chert; another type of stone-graywacke; a non-stone support-stainless steel), were stored in a room, in non-sterile and fluctuating conditions, for lengths of time ranging from 3 to 18 months. Afterwards, the specimens were coated with gold and examined by a Cambridge Stereoscan 120 scanning electron microscope. Results revealed a high preservation of RBC integrity, with the maintenance of several discocytary shapes, a low tendency to echinocytosis and a frequent appearance of a moon-like erythrocytary shape in the thinner areas of the bloodstains. PMID:1398371

  2. Image-based red cell counting for wild animals blood.

    PubMed

    Mauricio, Claudio R M; Schneider, Fabio K; Dos Santos, Leonilda Correia

    2010-01-01

    An image-based red blood cell (RBC) automatic counting system is presented for wild animals blood analysis. Images with 2048×1536-pixel resolution acquired on an optical microscope using Neubauer chambers are used to evaluate RBC counting for three animal species (Leopardus pardalis, Cebus apella and Nasua nasua) and the error found using the proposed method is similar to that obtained for inter observer visual counting method, i.e., around 10%. Smaller errors (e.g., 3%) can be obtained in regions with less grid artifacts. These promising results allow the use of the proposed method either as a complete automatic counting tool in laboratories for wild animal's blood analysis or as a first counting stage in a semi-automatic counting tool. PMID:21096766

  3. Iron-Deficiency Anemia Enhances Red Blood Cell Oxidative Stress

    PubMed Central

    Nagababu, Enika; Gulyani, Seema; Earley, Christopher J.; Cutler, Roy G.; Mattson, Mark P.; Rifkind, Joseph M.

    2009-01-01

    Oxidative stress associated with iron deficiency anemia in a murine model was studied feeding an iron deficient diet. Anemia was monitored by a decrease in hematocrit and hemoglobin. For the 9 week study an increase in total iron binding capacity was also demonstrated. Anemia resulted in an increase in red blood cells (RBC) oxidative stress as indicated by increased levels of fluorescent heme degradation products (1.24 fold after 5 weeks; 2.1 fold after 9 weeks). The increase in oxidative stress was further confirmed by elevated levels of methemoglobin for mice fed an iron deficient diet. Increased hemoglobin autoxidation and subsequent generation of ROS can account for the shorter RBC lifespan and other pathological changes associated with iron deficiency anemia. PMID:19051108

  4. Dynamics of flat membranes and flickering in red blood cells

    NASA Astrophysics Data System (ADS)

    Frey, Erwin; Nelson, David R.

    1991-12-01

    A theory of the dynamics of polymerized membranes in the flat phase is presented. The dynamics of dilute membrane solutions is strongly influenced by long-ranged hydrodynamic interactions among the monomers, mediated by the intervening solvent. We discuss the renormalization of the kinetic coefficients for the undulation and phonon modes due to hydrodynamic “backflow” (Zimm behavior). The dynamics is also studied for free draining membranes (Rouse dynamics) corresponding to the Brownian dynamics method used in Monte Carlo simulations. The long time behavior of the dynamic structure factor is given by stretched exponentials with stretching exponents determined by the exponents of the elastic coefficients and the wave vector dependence of the Oseen tensor. We also study the dynamics of the thickness fluctuations in red blood cells (flicker phenomenon) taking into account the underlying polymerized spectrin skeleton. Qualitatively different dynamical behavior is predicted for spectrin skeletons isolated from heir natural lipid environment.

  5. Discrimination of T-cell subsets and T-cell receptor repertoire distribution.

    PubMed

    Bretschneider, Isabell; Clemente, Michael J; Meisel, Christian; Guerreiro, Manuel; Streitz, Mathias; Hopfenmüller, Werner; Maciejewski, Jaroslav P; Wlodarski, Marcin W; Volk, Hans-Dieter

    2014-01-01

    Flow cytometry-based analysis of T-cell receptor (TCR) repertoires is an essential tool for the detection of clonal T-cell expansions in physiologic and pathologic conditions. Individual T-cell subsets can be investigated based on their surface properties. The aims of our study were to provide reference values for various disease settings and delineate the contribution of individual TCR repertoires to the human T-cell differentiation pathway. We analyzed blood of 66 healthy subjects aged 0 (cord blood) to 72 years. Lymphocyte subpopulations and TCR repertoires were simultaneously explored using antibodies specific to CD3, CD4, CD8, CD45RA, CCR7, CD27, CD57 and a set of 25 antibodies detecting human TCR-Vβ chains. Statistical analysis included Wilcoxon, paired t and ANOVA tests. Initially, TCR expansion values were calculated based on the analysis of TCR-Vβ distribution on CD4+ and CD8+ T cells. We then established gating strategies and an algorithm for data analysis allowing for discrimination of T-cell subsets and TCR distribution. Dominant TCR expansions were present within effector as opposed to central/effector memory or naive cells, e.g., median TCR-Vβ expansion rate was highest on CD45RA+/CCR7- effector CD4+/8+ cells (eight and 11-fold, respectively). Remarkably, TCR expansions were missing (0) or very low (0.5) on CD4+ and CD8+ central memory population, respectively. No significant gender-related variability of TCR repertoires was identified, and significant impact of chronic cytomegalovirus infection was shown. Our results serve as reference for future studies elucidating clonal TCR dominance of T-cell subsets. PMID:24272857

  6. Anemia and red blood cell transfusion in neurocritical care

    PubMed Central

    Kramer, Andreas H; Zygun, David A

    2009-01-01

    Introduction Anemia is one of the most common medical complications to be encountered in critically ill patients. Based on the results of clinical trials, transfusion practices across the world have generally become more restrictive. However, because reduced oxygen delivery contributes to 'secondary' cerebral injury, anemia may not be as well tolerated among neurocritical care patients. Methods The first portion of this paper is a narrative review of the physiologic implications of anemia, hemodilution, and transfusion in the setting of brain-injury and stroke. The second portion is a systematic review to identify studies assessing the association between anemia or the use of red blood cell transfusions and relevant clinical outcomes in various neurocritical care populations. Results There have been no randomized controlled trials that have adequately assessed optimal transfusion thresholds specifically among brain-injured patients. The importance of ischemia and the implications of anemia are not necessarily the same for all neurocritical care conditions. Nevertheless, there exists an extensive body of experimental work, as well as human observational and physiologic studies, which have advanced knowledge in this area and provide some guidance to clinicians. Lower hemoglobin concentrations are consistently associated with worse physiologic parameters and clinical outcomes; however, this relationship may not be altered by more aggressive use of red blood cell transfusions. Conclusions Although hemoglobin concentrations as low as 7 g/dl are well tolerated in most critical care patients, such a severe degree of anemia could be harmful in brain-injured patients. Randomized controlled trials of different transfusion thresholds, specifically in neurocritical care settings, are required. The impact of the duration of blood storage on the neurologic implications of transfusion also requires further investigation. PMID:19519893

  7. Pure red cell aplasia secondary to treatment with erythropoietin.

    PubMed

    Locatelli, Francesco; Del Vecchio, Lucia

    2003-01-01

    Pure red cell aplasia (PRCA) is a rare condition defined as severe anemia secondary to the virtual absence of red blood cell precursors in the bone marrow. In the setting of patients treated with rHuEPO, the disease is generated by epoetin-induced antibodies that neutralise all the exogenous rHuEPO and cross-react with endogenous erythropoietin. As a result, serum erythropoietin levels are undetectable and erythropoiesis becomes ineffective. Only 4 cases of PRCA associated with rh-EPO have been reported before 1998. Thereafter, a sharp increase in the incidence of this rare condition has been reported, mainly associated with epoetin alpha use outside the United States. A number of possible mechanisms leading to PRCA development have been identified. Among these, modification of drug formulation and down stream processing probably has had a major role. Indeed, in 1998 the formulation of epoetin alpha in Europe was modified because of the fear of the "mad cow" syndrome. However, differences in molecule structure and glycosylation among different epoetins can not be excluded. It should also be underlined that the rise in the incidence of PRCA cases has been coincident with a major shift from intravenous to subcutaneous administration of rHuEPO. The abrupt rise in the incidence of PRCA cases observed in the last few years, deserves particular attention; however, we have to balance its severity, but extreme rarity, with the high number of chronic kidney disease patients who die each year because of cardiovascular disease that could partially be reduced by anemia treatment. PMID:14696747

  8. Red blood cells do not contribute to removal of K+ released from exhaustively working forearm muscle.

    PubMed

    Maassen, N; Foerster, M; Mairbäurl, H

    1998-07-01

    K+ released from exercising muscle via K+ channels needs to be removed from the interstitium into the blood to maintain high muscle cell membrane potential and allow normal muscle contractility. Uptake by red blood cells has been discussed as one mechanism that would also serve to regulate red blood cell volume, which was found to be constant despite increased plasma osmolality and K+ concentration ([K+pl]). We evaluated exercise-related changes in [K+pl], pH, osmolality, mean cellular Hb concentration, cell water, and red blood cell K+ concentration during exhaustive handgrip exercise. Unidirectional 86Rb+ (K+) uptake by red blood cells was measured in media with elevated extracellular K+, osmolarity, and catecholamines to simulate particularly those exercise-related changes in plasma composition that are known to stimulate K+ uptake. During exercise [K+pl] increased from 4.4 +/- 0.7 to 7.1 +/- 0.5 mmol/l plasma water and red blood cell K+ concentration increased from 137.2 +/- 6.0 to 144.6 +/- 4.6 mmol/l cell water (P red blood cells was increased by approximately 20% on stimulation, caused by activation of the Na+-K+ pump and Na+-K+-2Cl- cotransport. Results indicate the K+ content of red blood cells did not change as cells passed the exhaustively exercising forearm muscle despite the elevated [K+pl]. The tendency for an increase in intracellular K+ concentration was due to a slight, although statistically not significant, decrease in red blood cell volume. K+ uptake, although elevated, was too small to move significant amounts of K+ into red blood cells. Our results suggest that red blood cells do not contribute to the removal of K+ released from muscle and do not regulate their volume by K+ uptake during exhaustive forearm exercise. PMID:9655793

  9. Integration of red cell genotyping into the blood supply chain: a population-based study

    PubMed Central

    Flegel, Willy A; Gottschall, Jerome L; Denomme, Gregory A

    2015-01-01

    Background When problems with compatibility arise, transfusion services often perform time-consuming serologic testing to locate antigen-negative red cell units for safe transfusion. New technologies enabled red cell genotyping for all clinically relevant blood group antigens. We performed mass-scale genotyping and provided access to a large red cell database to meet the demand for antigen-negative red cell units beyond ABO and Rh. Methods A red cell genotype database was established in 2010. Hospitals were given online access to a web-based antigen query portal in 2013 to find antigen-negative units in their inventories. Findings Genotype data were analyzed for 43,066 blood donors covering a set of 42 clinically relevant red cell antigens. Requests were filled for 5661 of 5672 patient encounters (99.8%) requiring antigen-negative red cell units in a multi-ethnic and multi-racial population. Red cell genotyping met the demand for antigen-negative blood in 5339 of 5672 (95%) patient encounters, while 333 remaining requests were filled using serologic data. In a pilot phase, seven community and rural transfusion services searched their local inventories using an online antigen query portal. Interpretation Red cell genotyping has the potential to transform the way antigen-negative red cell units are provided. An antigen query portal may reduce the need to ship blood or perform serologic screening. The wealth of genotype data, easily accessible online, facilitates the supply of affordable antigen-negative red cell units for patient safety. Physicians may recognize these new efficiencies for patient transfusion support. Funding BloodCenter of Wisconsin Diagnostic Laboratories Strategic Initiative and the NIH Clinical Center Intramural Research Program. PMID:26207259

  10. Peripheral red blood cell split chimerism as a consequence of intramedullary selective apoptosis of recipient red blood cells in a case of sickle cell disease.

    PubMed

    Marziali, Marco; Isgrò, Antonella; Sodani, Pietro; Gaziev, Javid; Fraboni, Daniela; Paciaroni, Katia; Gallucci, Cristiano; Alfieri, Cecilia; Roveda, Andrea; De Angelis, Gioia; Cardarelli, Luisa; Ribersani, Michela; Andreani, Marco; Lucarelli, Guido

    2014-01-01

    Allogeneic cellular gene therapy through hematopoietic stem cell transplantation is the only radical cure for congenital hemoglobinopathies like thalassemia and sickle cell anemia. Persistent mixed hematopoietic chimerism (PMC) has been described in thalassemia and sickle cell anemia. Here, we describe the clinical course of a 6-year-old girl who had received bone marrow transplant for sickle cell anemia. After the transplant, the patient showed 36% donor hematopoietic stem cells in the bone marrow, whereas in the peripheral blood there was evidence of 80% circulating donor red blood cells (RBC). The analysis of apoptosis at the Bone Marrow level suggests that Fas might contribute to the cell death of host erythroid precursors. The increase in NK cells and the regulatory T cell population observed in this patient suggests that these cells might contribute to the condition of mixed chimerism. PMID:25408852

  11. Peripheral Red Blood Cell Split Chimerism as a Consequence of Intramedullary Selective Apoptosis of Recipient Red Blood Cells in a Case of Sickle Cell Disease

    PubMed Central

    Marziali, Marco; Isgrò, Antonella; Sodani, Pietro; Gaziev, Javid; Fraboni, Daniela; Paciaroni, Katia; Gallucci, Cristiano; Alfieri, Cecilia; Roveda, Andrea; De Angelis, Gioia; Cardarelli, Luisa; Ribersani, Michela; Andreani, Marco; Lucarelli, Guido

    2014-01-01

    Allogeneic cellular gene therapy through hematopoietic stem cell transplantation is the only radical cure for congenital hemoglobinopathies like thalassemia and sickle cell anemia. Persistent mixed hematopoietic chimerism (PMC) has been described in thalassemia and sickle cell anemia. Here, we describe the clinical course of a 6-year-old girl who had received bone marrow transplant for sickle cell anemia. After the transplant, the patient showed 36% donor hematopoietic stem cells in the bone marrow, whereas in the peripheral blood there was evidence of 80% circulating donor red blood cells (RBC). The analysis of apoptosis at the Bone Marrow level suggests that Fas might contribute to the cell death of host erythroid precursors. The increase in NK cells and the regulatory T cell population observed in this patient suggests that these cells might contribute to the condition of mixed chimerism. PMID:25408852

  12. Detection and quantification of subtle changes in red blood cell density using a cell phone.

    PubMed

    Felton, Edward J; Velasquez, Anthony; Lu, Shulin; Murphy, Ryann O; ElKhal, Abdala; Mazor, Ofer; Gorelik, Pavel; Sharda, Anish; Ghiran, Ionita C

    2016-08-16

    Magnetic levitation has emerged as a technique that offers the ability to differentiate between cells with different densities. We have developed a magnetic levitation system for this purpose that distinguishes not only different cell types but also density differences in cells of the same type. This small-scale system suspends cells in a paramagnetic medium in a capillary placed between two rare earth magnets, and cells levitate to an equilibrium position determined solely by their density. Uniform reference beads of known density are used in conjunction with the cells as a means to quantify their levitation positions. In one implementation images of the levitating cells are acquired with a microscope, but here we also introduce a cell phone-based device that integrates the magnets, capillary, and a lens into a compact and portable unit that acquires images with the phone's camera. To demonstrate the effectiveness of magnetic levitation in cell density analysis we carried out levitation experiments using red blood cells with artificially altered densities, and also levitated those from donors. We observed that we can distinguish red blood cells of an anemic donor from those that are healthy. Since a plethora of disease states are characterized by changes in cell density magnetic cell levitation promises to be an effective tool in identifying and analyzing pathologic states. Furthermore, the low cost, portability, and ease of use of the cell phone-based system may potentially lead to its deployment in low-resource environments. PMID:27431921

  13. Manipulation of red blood cells with electric field

    NASA Astrophysics Data System (ADS)

    Saboonchi, Hossain; Esmaeeli, Asghar

    2009-11-01

    Manipulation of bioparticles and macromolecules is the central task in many biological and biotechnological processes. The current methods for physical manipulation takes advantage of different forces such as acoustic, centrifugal, magnetic, electromagnetic, and electric forces, as well as using optical tweezers or filtration. Among all these methods, however, the electrical forces are particularly attractive because of their favorable scale up with the system size which makes them well-suited for miniaturization. Currently the electric field is used for transportation, poration, fusion, rotation, and separation of biological cells. The aim of the current research is to gain fundamental understanding of the effect of electric field on the human red blood cells (RBCs) using direct numerical simulation. A front tracking/finite difference technique is used to solve the fluid flow and electric field equations, where the fluid in the cell and the blood (plasma) is modeled as Newtonian and incompressible, and the interface separating the two is treated as an elastic membrane. The behavior of RBCs is investigated as a function of the controlling parameters of the problem such as the strength of the electric field.

  14. Of macrophages and red blood cells; a complex love story.

    PubMed

    de Back, Djuna Z; Kostova, Elena B; van Kraaij, Marian; van den Berg, Timo K; van Bruggen, Robin

    2014-01-01

    Macrophages tightly control the production and clearance of red blood cells (RBC). During steady state hematopoiesis, approximately 10(10) RBC are produced per hour within erythroblastic islands in humans. In these erythroblastic islands, resident bone marrow macrophages provide erythroblasts with interactions that are essential for erythroid development. New evidence suggests that not only under homeostasis but also under stress conditions, macrophages play an important role in promoting erythropoiesis. Once RBC have matured, these cells remain in circulation for about 120 days. At the end of their life span, RBC are cleared by macrophages residing in the spleen and the liver. Current theories about the removal of senescent RBC and the essential role of macrophages will be discussed as well as the role of macrophages in facilitating the removal of damaged cellular content from the RBC. In this review we will provide an overview on the role of macrophages in the regulation of RBC production, maintenance and clearance. In addition, we will discuss the interactions between these two cell types during transfer of immune complexes and pathogens from RBC to macrophages. PMID:24523696

  15. Fibrinogen and red blood cells in venous thrombosis

    PubMed Central

    Aleman, Maria M.; Walton, Bethany L.; Byrnes, James R.; Wolberg, Alisa S.

    2014-01-01

    Deep vein thrombosis and pulmonary embolism, collectively termed venous thromboembolism (VTE), affect over 1 million Americans each year. VTE is triggered by inflammation and blood stasis leading to the formation of thrombi rich in fibrin and red blood cells (RBCs). However, little is known about mechanisms regulating fibrin and RBC incorporation into venous thrombi, or how these components mediate thrombus size or resolution. Both elevated circulating fibrinogen (hyperfibrinogenemia) and abnormal fibrin(ogen) structure and function, including increased fibrin network density and resistance to fibrinolysis, have been observed in plasmas from patients with VTE. Abnormalities in RBC number and/or function have also been associated with VTE risk. RBC contributions to VTE are thought to stem from their effects on blood viscosity and margination of platelets to the vessel wall. More recent studies suggest RBCs also express phosphatidylserine, support thrombin generation, and decrease fibrinolysis. RBC interactions with fibrin(ogen) and cells, including platelets and endothelial cells, may also promote thrombus formation. The contributions of fibrin(ogen) and RBCs to the pathophysiology of VTE warrants further investigation. PMID:24759140

  16. Red Blood Cells Play a Role in Reverse Cholesterol Transport

    PubMed Central

    Hung, Kimberly T.; Berisha, Stela Z.; Ritchey, Brian M.; Santore, Jennifer; Smith, Jonathan D.

    2012-01-01

    Objective Reverse cholesterol transport (RCT) involves the removal of cholesterol from peripheral tissue for excretion in the feces. Here, we determined whether red blood cells (RBCs) can contribute to RCT. Methods and Results We performed a series of studies in apoAI-deficient mice where the HDL-mediated pathway of RCT is greatly diminished. RBCs carried a higher fraction of whole blood cholesterol than plasma in apoAI-deficient mice, and as least as much of the labeled cholesterol derived from injected foam cells appeared in RBCs compared to plasma. To determine if RBCs mediate RCT to the fecal compartment, we measured RCT in anemic and control apoAI-deficient mice and found that anemia decreased RCT to the feces by over 35% after correcting for fecal mass. Transfusion of [3H]cholesterol labeled RBCs led to robust delivery of the labeled cholesterol to the feces in apoAI-deficient hosts. In wild type mice, the majority of the blood cholesterol mass, as well as [3H]cholesterol derived from the injected foam cells, was found in plasma, and anemia did not significantly alter RCT to the feces after correction for fecal mass. Conclusion The RBC cholesterol pool is dynamic and facilitates RCT of peripheral cholesterol to the feces, particularly in the low HDL state. PMID:22499994

  17. Cytoskeletal control of the red-blood cell membrane

    NASA Astrophysics Data System (ADS)

    Gov, Nir; Safran, Sam

    2004-03-01

    We have shown (Physical Review Letters, 90, 228101 (2003)) that the thermal fluctuations of red blood cells can be accounted for by a model of a nearly-free, but confined bilayer membrane with a finite tension; both the confinement and tension arise from the coupling of the membrane with the cytoskeleton. Recently, we have shown that these relatively gentle effects of the cytoskeleton-membrane couplings on the membrane fluctuations are due to the dilute nature of the coupling molecules. To quantify this, we predict the fluctuation amplitude for a microscopic model of the inhomogeneous coupling of a fluid membrane and a fixed cytoskeleton. The coupling is modeled as periodic and harmonic, and we consider the linear response of the membrane. We find that there is indeed, an effective surface tension and confinement of such a membrane, in accord with our phenomenological model, and relate these quantities to the strength and periodicity of the microscopic coupling. We also find, surprisingly, that the membrane can develop a spontaneous breaking of the cytoskeleton symmetry, at low confinements. Finally we address the role of ATP activity on the cytoskeleton-driven fluctuations and the equilibrium shape of the cell. We examine in detail the role of spectrin disconnections as the main ATP-activated network defects on the global cell shape and membrane fluctuations.

  18. Loss of deformability of malaria-infected red blood cells

    NASA Astrophysics Data System (ADS)

    Hosseini, S. Majid; Feng, James

    2012-11-01

    The pathogenesis of malaria is largely due to stiffening of the infected red blood cells (RBCs). Contemporary understanding ascribes the loss of RBC deformability to a 10-fold increase in membrane stiffness caused by extra cross-linking in the spectrin network. Local measurements by micropipette aspiration, however, have reported only an increase of 3-fold in the shear modulus. We believe the discrepancy stems from the rigid parasite particles inside infected cells, and have carried out numerical simulations to demonstrate this mechanism. The cell membrane is represented by a set of discrete particles connected by linearly elastic springs. The cytosol is modeled as a homogeneous Newtonian fluid, and discretized by particles as in standard smoothed particle hydrodynamics. The malaria parasite is modeled as an aggregate of particles constrained to rigid-body motion. We simulate RBC stretching tests by optical tweezers in three dimensions. The results demonstrate that the presence of a sizeable parasite greatly reduces the ability of RBCs to deform under stretching. With the solid inclusion, the observed loss of deformability can be predicted quantitatively using the local membrane elasticity measured by micropipettes.

  19. Red blood cell as an adaptive optofluidic microlens

    NASA Astrophysics Data System (ADS)

    Miccio, L.; Memmolo, P.; Merola, F.; Netti, P. A.; Ferraro, P.

    2015-03-01

    The perspective of using live cells as lenses could open new revolutionary and intriguing scenarios in the future of biophotonics and biomedical sciences for endoscopic vision, local laser treatments via optical fibres and diagnostics. Here we show that a suspended red blood cell (RBC) behaves as an adaptive liquid-lens at microscale, thus demonstrating its imaging capability and tunable focal length. In fact, thanks to the intrinsic elastic properties, the RBC can swell up from disk volume of 90 fl up to a sphere reaching 150 fl, varying focal length from negative to positive values. These live optofluidic lenses can be fully controlled by triggering the liquid buffer’s chemistry. Real-time accurate measurement of tunable focus capability of RBCs is reported through dynamic wavefront characterization, showing agreement with numerical modelling. Moreover, in analogy to adaptive optics testing, blood diagnosis is demonstrated by screening abnormal cells through focal-spot analysis applied to an RBC ensemble as a microlens array.

  20. Red Blood Cell Susceptibility to Pneumolysin: CORRELATION WITH MEMBRANE BIOCHEMICAL AND PHYSICAL PROPERTIES.

    PubMed

    Bokori-Brown, Monika; Petrov, Peter G; Khafaji, Mawya A; Mughal, Muhammad K; Naylor, Claire E; Shore, Angela C; Gooding, Kim M; Casanova, Francesco; Mitchell, Tim J; Titball, Richard W; Winlove, C Peter

    2016-05-01

    This study investigated the effect of the biochemical and biophysical properties of the plasma membrane as well as membrane morphology on the susceptibility of human red blood cells to the cholesterol-dependent cytolysin pneumolysin, a key virulence factor of Streptococcus pneumoniae, using single cell studies. We show a correlation between the physical properties of the membrane (bending rigidity and surface and dipole electrostatic potentials) and the susceptibility of red blood cells to pneumolysin-induced hemolysis. We demonstrate that biochemical modifications of the membrane induced by oxidative stress, lipid scrambling, and artificial cell aging modulate the cell response to the toxin. We provide evidence that the diversity of response to pneumolysin in diabetic red blood cells correlates with levels of glycated hemoglobin and that the mechanical properties of the red blood cell plasma membrane are altered in diabetes. Finally, we show that diabetic red blood cells are more resistant to pneumolysin and the related toxin perfringolysin O relative to healthy red blood cells. Taken together, these studies indicate that the diversity of cell response to pneumolysin within a population of human red blood cells is influenced by the biophysical and biochemical status of the plasma membrane and the chemical and/or oxidative stress pre-history of the cell. PMID:26984406

  1. Macrophages and iron trafficking at the birth and death of red cells

    PubMed Central

    Korolnek, Tamara

    2015-01-01

    Macrophages play a critical role in iron homeostasis via their intimate association with developing and dying red cells. Central nurse macrophages promote erythropoiesis in the erythroblastic island niche. These macrophages make physical contact with erythroblasts, enabling signaling and the transfer of growth factors and possibly nutrients to the cells in their care. Human mature red cells have a lifespan of 120 days before they become senescent and again come into contact with macrophages. Phagocytosis of red blood cells is the main source of iron flux in the body, because heme must be recycled from approximately 270 billion hemoglobin molecules in each red cell, and roughly 2 million senescent red cells are recycled each second. Here we will review pathways for iron trafficking found at the macrophage-erythroid axis, with a focus on possible roles for the transport of heme in toto. PMID:25778532

  2. Density increment and decreased survival of rat red blood cells induced by cadmium

    SciTech Connect

    Kunimoto, M.; Miura, T.

    1986-01-01

    Male Wistar rats were injected with CdCl/sub 2/ subcutaneously to examine in vivo effects of Cd on density and survival of red blood cells. During the 7 days after administration of 1.0 mg Cd/kg, the following sequence of events occurred: (1) a progressive increase in the amount of more dense red blood cells concomitant with a decrease in that of light red blood cells from the first to the third day; (2) an increase in the spleen weight at the third day; (3) a decrease in the hematocrit value and an increase in the amount of light red blood cells at the fifth day; and (4) a recovery of the hematocrit value at the seventh day. Five days after administration, the hematocrit value decreased in a dose-dependent mode and the decrease was significant at the 1% level at 1.0 and 1.5 mg Cd/kg. A highly significant splenomegaly was also observed at 0.5 to 1.5 mg Cd/kg. In order to label red blood cells in vivo, (/sup 3/H) diisopropylfluorophosphate ((/sup 3/H)DFP) was injected into rats. At Day 11, Cd at either 0.5 or 1.0 mg/kg was administered to (/sup 3/H)DFP-prelabeled animals. Cd administration accelerated /sup 3/H-labeled red cell clearance from the blood. Six days after Cd administration, the radioactivity of red blood cells was 76 and 68% of the control at 0.5 and 1.0 mg Cd/kg, respectively. In vitro treatment of rat red density and accelerated in vivo clearance of red blood cells from the recipient circulation. These results show that Cd at low dose can cause anemia by increasing red cell density and by accelerating red cell sequestration, presumably in the spleen.

  3. Red Ginseng Extract Reduced Metastasis of Colon Cancer Cells In Vitro and In Vivo

    PubMed Central

    Seo, Eun Young; Kim, Woo Kyoung

    2011-01-01

    This study investigated the effect of red ginseng extract on metastasis of colon cancer cells in vitro and in vivo. Wound healing migration, cell motility, invasion, and activity, protein expression, and mRNA expression of matrix metalloproteinases (MMPs) were examined in SW480 human colon cancer cells. SW480 cells were cultured with or without 100 μg/L PMA in the absence or presence of various concentrations (100, 200, or 300 μg/mL) of red ginseng extract. Red ginseng extract treatment caused significant suppression of cell motility and invasion (p<0.05) in SW480 cells. Red ginseng extract inhibited MMP-2 and MMP-9 activity and their protein and mRNA expression in a dose-dependent manner (p<0.05) in SW480 cells. For experimental metastasis, BALB/c mice were injected intravenously with CT-26 mouse colon cancer cells in the tail vein, and were orally administered various concentrations (0, 75, 150, or 300 mg/kg body weight) of red ginseng extract for 3 weeks. Numbers of pulmonary nodules were significantly decreased in mice that were fed red ginseng extract (p<0.05). Plasma MMP-2 and MMP-9 activity significantly decreased in response to treatment with red ginseng extract in mice (p<0.05). These data suggest that red ginseng extract may be useful for prevention of cancer invasion and metastasis through inhibition of MMP-2 and MMP-9 pathways. PMID:23717075

  4. Modulation of ligand-mediated human red cell agglutinability by prostaglandins

    SciTech Connect

    McLawhon, R.W.; Marikovsky, Y.; Weinstein, R.S.

    1986-03-01

    Ethanol induces the transformation of human red cells from bioconcave discs to echinocytes in vitro. In addition, they have observed that ethanol can enhance the agglutination of red cells by the plant lectin wheat germ agglutinin or poly-L-lysine. Incubation of washed human red cells with 5 and 10% ethanol (v/v) in phosphate buffered saline, pH 7.3 at 25/sup 0/C produced a 30% increase in ligand-mediated agglutinability within 12 min. Simultaneous addition of ethanol and one of the following prostaglandin derivatives, PGE/sub 1/, pge/sub 2/, pgf/sub 2/-alpha, or PGl/sub 2/ (10/sup -9/ to 5 x 10/sup -7/ M) prevented the shape-associated increases in red cell agglutinability. Thromboxane-B/sub 2/ had no effect on agglutinability. Prostaglandins did not prevent ethanol-induced red cell shape transformations per se under identical experimental conditions. As intragastric administration of 100% ethanol results in the formation of spiculated red cell thrombi in postcapillary venules of rat gastric mucosa, they postulate that the cytoprotective role of prostanoids in preventing mucosal ulceration may be due in part to their capacity to inhibit intravascular ligand mediated red cell agglutination, hemostasis, and their sequelae, epithelial necrosis. Moreover, the data suggest that ethanol-induced red cell shape transformations and ligand-mediated agglutination represent two distinct and independent biological phenomena.

  5. Kit for the selective labeling of red blood cells in whole blood with .sup.9 TC

    DOEpatents

    Srivastava, Suresh C.; Babich, John W.; Straub, Rita; Richards, Powell

    1992-01-01

    Disclosed herein are a method and kit for the preparation of .sup.99m Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium.

  6. Kit for the selective labeling of red blood cells in whole blood with [sup 99]Tc

    DOEpatents

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1992-05-26

    Disclosed herein are a method and kit for the preparation of [sup 99m]Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium. No Drawings

  7. Antibody-mediated red blood cell agglutination resulting in spontaneous echocardiographic contrast.

    PubMed

    Miller, M R; Thompson, W R; Casella, J F; Spevak, P J

    1999-01-01

    Spontaneous echocardiographic contrast is well reported in states of low flow and low shear stress, and the primary blood component involved has been reported as red blood cells via rouleaux formation. This report describes the occurrence of spontaneous echocardiographic contrast from a unique mechanism of IgM-mediated red blood cell agglutination and describes the clinical sequelae. PMID:10368455

  8. Texture discrimination by cells in the cat lateral geniculate nucleus.

    PubMed

    Nothdurft, H C

    1990-01-01

    The spontaneous segregation of texture areas is an impressive perceptual phenomenon, the neural basis of which is not yet understood. In the texton concept (Julesz and Bergen 1983; Julesz 1984, 1986) it is assumed that the visual system analyzes a stimulus for certain features ('textons') the spatial distribution of which is pre-attentively registered and may provide the percept of dissected texture areas. Supposed textons are blobs of a given size, oriented lines, line intersections and line terminators, suggesting that texture analysis is exclusively mediated by form-specific filters at higher, e.g. cortical, processing levels. This paper investigates the contribution of cells in the cat lateral geniculate nucleus (LGN) to segregation of typical texton differences. The results indicate that LGN cells, though not resembling the supposed texton filters, often distinguished textured arrangements of such features on the basis of a variety of other visual cues, such as global or local variations in mean luminance or differences in spatial frequency composition. Thus, cells responded to texture borders between areas differing in the size or the density of texture elements and often revealed differential firing rates to textures differing by the crossing or the terminator feature. For textures with differences in line orientation, however, only small variations of the firing rate were seen. In summary, the observations suggest a means of texture representation in the cat LGN which is different from recent concepts of texture segregation in man. For a given pair of textures, cells with receptive fields larger than, or similar to the texture raster respond to global and local luminance variations between areas and, in particular, to differences in their spatial frequency composition. These cells, hence, may signal the global texture difference without encoding spatial details of the pattern from which texton features could be identified. Cells with receptive fields small

  9. Raman spectroscopy as a tool for label-free lymphocyte cell line discrimination.

    PubMed

    Hobro, Alison J; Kumagai, Yutaro; Akira, Shizuo; Smith, Nicholas I

    2016-06-21

    Unactivated lymphocytes are morphologically identical and biochemically relatively similar, making them difficult to distinguish from one another with conventional light microscopy. Here, we use Raman spectroscopy to provide biochemical information on the composition of different lymphocyte cell lines. As could be expected, the biochemical differences measured with Raman spectroscopy between lymphocyte cell lines are small, but in combination with partial least squares discriminant analysis it is possible not only to distinguish between T- and B-cells, but also between individual T-cell and B-cell lines. PMID:27067644

  10. Mach-Zehnder interferometer for separation of platelets from red blood cells using dielectrophoretics

    NASA Astrophysics Data System (ADS)

    Shwetha, M.; Narayan, K.

    2016-03-01

    In this work, separation of platelets from red blood cells using Mach-Zehnder interferometer is shown using Dielectrophoretics (DEP). The proposed model demonstrates continuous separation of platelets from red blood cells. Mach-Zehnder Interferometer (MZI) has two arms, in which sensing arm will sense according to the applied voltage and separate the platelets from mixed blood cells. The platelets and the red blood cells will flow in two outlets of MZI. Microfluidic device is used to separate the RBC's and the platelets from the mixed blood cells.

  11. Targeted erythropoietin selectively stimulates red blood cell expansion in vivo.

    PubMed

    Burrill, Devin R; Vernet, Andyna; Collins, James J; Silver, Pamela A; Way, Jeffrey C

    2016-05-10

    The design of cell-targeted protein therapeutics can be informed by natural protein-protein interactions that use cooperative physical contacts to achieve cell type specificity. Here we applied this approach in vivo to the anemia drug erythropoietin (EPO), to direct its activity to EPO receptors (EPO-Rs) on red blood cell (RBC) precursors and prevent interaction with EPO-Rs on nonerythroid cells, such as platelets. Our engineered EPO molecule was mutated to weaken its affinity for EPO-R, but its avidity for RBC precursors was rescued via tethering to an antibody fragment that specifically binds the human RBC marker glycophorin A (huGYPA). We systematically tested the impact of these engineering steps on in vivo markers of efficacy, side effects, and pharmacokinetics. huGYPA transgenic mice dosed with targeted EPO exhibited elevated RBC levels, with only minimal platelet effects. This in vivo selectivity depended on the weakening EPO mutation, fusion to the RBC-specific antibody, and expression of huGYPA. The terminal plasma half-life of targeted EPO was ∼28.3 h in transgenic mice vs. ∼15.5 h in nontransgenic mice, indicating that huGYPA on mature RBCs acted as a significant drug sink but did not inhibit efficacy. In a therapeutic context, our targeting approach may allow higher restorative doses of EPO without platelet-mediated side effects, and also may improve drug pharmacokinetics. These results demonstrate how rational drug design can improve in vivo specificity, with potential application to diverse protein therapeutics. PMID:27114509

  12. Effect of Hydroperoxides on Red Blood Cell Membrane Mechanical Properties

    PubMed Central

    Hale, John P.; Winlove, C. Peter; Petrov, Peter G.

    2011-01-01

    We investigate the effect of oxidative stress on red blood cell membrane mechanical properties in vitro using detailed analysis of the membrane thermal fluctuation spectrum. Two different oxidants, the cytosol-soluble hydrogen peroxide and the membrane-soluble cumene hydroperoxide, are used, and their effects on the membrane bending elastic modulus, surface tension, strength of confinement due to the membrane skeleton, and 2D shear elastic modulus are measured. We find that both oxidants alter significantly the membrane elastic properties, but their effects differ qualitatively and quantitatively. While hydrogen peroxide mainly affects the elasticity of the membrane protein skeleton (increasing the membrane shear modulus), cumene hydroperoxide has an impact on both membrane skeleton and lipid bilayer mechanical properties, as can be seen from the increased values of the shear and bending elastic moduli. The biologically important implication of these results is that the effects of oxidative stress on the biophysical properties, and hence the physiological functions, of the cell membrane depend on the nature of the oxidative agent. Thermal fluctuation spectroscopy provides a means of characterizing these different effects, potentially in a clinical milieu. PMID:22004746

  13. Reduction of prion infectivity in packed red blood cells

    SciTech Connect

    Morales, Rodrigo; Buytaert-Hoefen, Kimberley A.; Gonzalez-Romero, Dennisse; Castilla, Joaquin; Hansen, Eric T.; Hlavinka, Dennis; Goodrich, Raymond P.; Soto, Claudio

    2008-12-12

    The link between a new variant form of Creutzfeldt-Jakob disease (vCJD) and the consumption of prion contaminated cattle meat as well as recent findings showing that vCJD can be transmitted by blood transfusion have raised public health concerns. Currently, a reliable test to identify prions in blood samples is not available. The purpose of this study was to evaluate the possibility to remove scrapie prion protein (PrP{sup Sc}) and infectivity from red blood cell (RBC) suspensions by a simple washing procedure using a cell separation and washing device. The extent of prion removal was assessed by Western blot, PMCA and infectivity bioassays. Our results revealed a substantial removal of infectious prions ({>=}3 logs of infectivity) by all techniques used. These data suggest that a significant amount of infectivity present in RBC preparations can be removed by a simple washing procedure. This technology may lead to increased safety of blood products and reduce the risk of further propagation of prion diseases.

  14. The aging of the red blood cell. A multifactor process.

    PubMed

    Danon, D; Marikovsky, Y

    1988-01-01

    Red blood cell (rbc) senescence is associated with loss of surface sialic acid, which is the principal carrier of surface negative charge and determines the electrokinetic behavior of old rbcs. Loss of sialic acid in an old rbc is demonstrated in its decreased electric mobility and lower negative charge density, determined topographically with cationic particle labeling. Surface sialic acid determines also the mutual attraction--repulsion forces, as demonstrated in enhanced aggluinability with cationic molecules, lectins, and blood group antibodies. Loss of sialic acid accompanies ATP-depletion in vitro; thus, a T-antigen site is unmasked. Macrophages have specific receptors to the site as to newly exposed galactose and N-acetyl galactosamine sugars. Furthermore, the involvement of complement molecules in the recognition of old RBCs by macrophages has been shown. This is possibly due to loss of sialic acid or at least a regrouping--relocation of surface anionic sites due to cell shape changes from discocytes to crenated forms, which accompany both in vivo and in vitro rbc aging. In turn, shape changes are apparently controlled by the cytoskeletal network underlying the rbc membrane, which undergoes structural alteration with physiologic aging in changing the dimensions of oligomeric spectrin and the thickness of the spectrin-actin cytoskeletal assembly. PMID:3052636

  15. Kinematics of red cell aspiration by fluorescence-imaged microdeformation.

    PubMed

    Discher, D E; Mohandas, N

    1996-10-01

    Maps of fluorescing red cell membrane components on a pipette-aspirated projection are quantitated in an effort to elucidate and unify the heterogeneous kinematics of deformation. Transient gradients of diffusing fluorescent lipid first demonstrate the fluidity of an otherwise uniform-density bilayer and corroborate a "universal" calibration scale for relative surface density. A steep but smooth and stable gradient in the densities of the skeleton components spectrin, actin, and protein 4.1 is used to estimate large elastic strains along the aspirated skeleton. The deformation fields are argued to be an unhindered response to loading in the surface normal direction. Density maps intermediate to those of the compressible skeleton and fluid bilayer are exhibited by particular transmembrane proteins (e.g., Band 3) and yield estimates for the skeleton-connected fractions. Such connected proteins appear to occupy a significant proportion of the undeformed membrane surface and can lead to steric exclusion of unconnected integral membrane proteins from regions of network condensation. Consistent with membrane repatterning kinematics in reversible deformation, final vesiculation of the projection tip produces a cell fragment concentrated in freely diffusing proteins but depleted of skeleton. PMID:8889146

  16. Kinematics of red cell aspiration by fluorescence-imaged microdeformation.

    PubMed Central

    Discher, D E; Mohandas, N

    1996-01-01

    Maps of fluorescing red cell membrane components on a pipette-aspirated projection are quantitated in an effort to elucidate and unify the heterogeneous kinematics of deformation. Transient gradients of diffusing fluorescent lipid first demonstrate the fluidity of an otherwise uniform-density bilayer and corroborate a "universal" calibration scale for relative surface density. A steep but smooth and stable gradient in the densities of the skeleton components spectrin, actin, and protein 4.1 is used to estimate large elastic strains along the aspirated skeleton. The deformation fields are argued to be an unhindered response to loading in the surface normal direction. Density maps intermediate to those of the compressible skeleton and fluid bilayer are exhibited by particular transmembrane proteins (e.g., Band 3) and yield estimates for the skeleton-connected fractions. Such connected proteins appear to occupy a significant proportion of the undeformed membrane surface and can lead to steric exclusion of unconnected integral membrane proteins from regions of network condensation. Consistent with membrane repatterning kinematics in reversible deformation, final vesiculation of the projection tip produces a cell fragment concentrated in freely diffusing proteins but depleted of skeleton. Images FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 5 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 PMID:8889146

  17. Mechanical response of red blood cells entering a constriction.

    PubMed

    Zeng, Nancy F; Ristenpart, William D

    2014-11-01

    Most work on the dynamic response of red blood cells (RBCs) to hydrodynamic stress has focused on linear velocity profiles. Relatively little experimental work has examined how individual RBCs respond to pressure driven flow in more complex geometries, such as the flow at the entrance of a capillary. Here, we establish the mechanical behaviors of healthy RBCs undergoing a sudden increase in shear stress at the entrance of a narrow constriction. We pumped RBCs through a constriction in a microfluidic device and used high speed video to visualize and track the flow behavior of more than 4400 RBCs. We show that approximately 85% of RBCs undergo one of four distinct modes of motion: stretching, twisting, tumbling, or rolling. Intriguingly, a plurality of cells (∼30%) exhibited twisting (rotation around the major axis parallel to the flow direction), a mechanical behavior that is not typically observed in linear velocity profiles. We present detailed statistical analyses on the dynamics of each motion and demonstrate that the behavior is highly sensitive to the location of the RBC within the channel. We further demonstrate that the observed tumbling, twisting, and rolling rotations can be rationalized qualitatively in terms of rigid body mechanics. The detailed experimental statistics presented here should serve as a useful resource for modeling of RBC behavior under physiologically important flow conditions. PMID:25553197

  18. Twisting of Red Blood Cells Entering a Constriction

    NASA Astrophysics Data System (ADS)

    Zeng, Nancy; Ristenpart, William

    2014-11-01

    Most work on the dynamic response of red blood cells (RBCs) to hydrodynamic stress has focused on linear velocity profiles. Relatively little experimental work has examined how individual RBCs respond to pressure driven flow in more complex geometries, such as the flow at the entrance of a capillary. Here, we establish the mechanical behaviors of healthy RBCs undergoing a sudden increase in shear stress at the entrance of a narrow constriction. We pumped RBCs through a constriction in an ex vivo microfluidic device and used high speed video to visualize and track the flow behavior of more than 4,400 RBCs. We show that approximately 85% of RBCs undergo one of four distinct modes of motion: stretching, twisting, tumbling, or rolling. Intriguingly, a plurality of cells (~30%) exhibited twisting (rotation around the major axis parallel to the flow direction), a mechanical behavior that is not typically observed in linear velocity profiles. We examine the mechanical origin of twisting using, as a limiting case, the equations of motion for rigid ellipsoids, and we demonstrate that the observed rotation is qualitatively consistent with rigid body theory.

  19. Enhancement of red blood cell aggregation by plasma triglycerides.

    PubMed

    Cicha, I; Suzuki, Y; Tateishi, N; Maeda, N

    2001-01-01

    The effects of plasma triglycerides level on human red blood cells (RBCs) indices, hematological parameters, RBCs aggregation velocity and whole blood viscosity were studied at 2 hours after high-fat or low-fat meal. Proteins, triglycerides and cholesterol levels of plasma were analysed. The RBCs rouleaux formation rate was measured in 70% autologous plasma (with 30% phosphate-buffered saline, PBS) or 1 g/dl dextran T70 solution (with 4 g/dl bovine serum albumin) in PBS, using a low-shear rheoscope. The results were grouped according to triglycerides content in plasma. No significant difference in whole blood viscosity, hematological parameters, RBC indices, protein and cholesterol content was observed between high-fat and low-fat blood samples. There was a significant increase in rouleaux formation rate of samples with high triglyceride levels, when measured in 70% autologous plasma, but it was not significant in dextran T70 containing medium. In conclusion, the results obtained suggest that alteration of plasma lipid levels as well as possible changes in the cell membrane lipid composition lead to enhanced RBC aggregation. PMID:11564913

  20. “T cells integrate Local and Global cues to discriminate between structurally similar antigens”

    PubMed Central

    Voisinne, Guillaume; Nixon, Briana; Melbinger, Anna; Gasteiger, Georg; Vergassola, Massimo; Altan-Bonnet, Grégoire

    2015-01-01

    T lymphocytes’ ability to discriminate between structurally related antigens has been attributed to the unique signaling properties of the T cell receptor. However, recent studies have suggested that the output of this discrimination process is conditioned by environmental cues. Here we demonstrate how the IL-2 cytokine, collectively generated by strongly activated T cell clones, can induce weaker T cell clones to proliferate. We identify the PI3K pathway as being critical for integrating the antigen and cytokine responses and for controlling cell cycle entry. We build a hybrid stochastic/deterministic computational model that accounts for such signal-synergism and demonstrates quantitatively how T-cells tune their cell cycle entry according to environmental cytokine cues. Our findings indicate that antigen discrimination by T-cells is not solely an intrinsic cellular property but rather a product of integration of multiple cues, including local cues like antigen quality and quantity, to global ones like the extracellular concentration of inflammatory cytokines. PMID:26004178

  1. Red cell distribution width is a predictor of mortality in patients undergoing percutaneous coronary intervention.

    PubMed

    Fatemi, Omid; Paranilam, Jaya; Rainow, Alex; Kennedy, Kevin; Choi, Jason; Cutlip, Donald; Pencina, Michael; Berger, Peter B; Cohen, David J; Kleiman, Neal S

    2013-01-01

    Red cell distribution width (RDW), a measure of the variability in size of circulating erythrocytes, is an independent predictor of mortality in patients with cardiovascular disease. We hypothesized that RDW is a prognostic marker of death, myocardial infarction and unplanned revascularization in a broad population undergoing percutaneous coronary intervention (PCI). We investigated the prognostic value of RDW derived from a complete blood count drawn ≤24 h of PCI in 1,689 patients at four centers who underwent PCI between 2004 and 2007 in the evaluation of drug eluting stents and ischemic events registry. Patients who underwent blood transfusions were excluded. Multivariable analyses of death, MI, unplanned revascularization, and the combined occurrence of these events at 1 year were performed using methods from survival analysis. The analysis was adjusted for creatinine ≥1.5 mg/dL, hemoglobin, congestive heart failure, coronary artery bypass grafting history, male sex, BMI, atherosclerosis of ≥2 coronary vessels, and hypertension. In univariate analysis of RDW stratified by quartiles, membership in the highest quartile was a predictor of mortality as compared to the lowest quartile (HR 5.07, CI 2.07-12.40, p < 0.001). In multivariate analysis, RDW was not an independent predictor of unplanned revascularization after PCI; however, RDW remained an independent correlate of 1 year mortality (HR 1.65, CI 1.22-2.23, p = 0.001); with a continuous net reclassification improvement of 46.5% (95% CI 15.1-76.4%) and a relative integrated discrimination improvement of 57.8% (95% CI 22.1-94.9%) after PCI. RDW is a widely available independent correlate of 1-year mortality after PCI that increases the discriminative value of risk prediction in these patients. PMID:22752404

  2. Electrophoretic characterization of aldehyde-fixed red blood cells, kidney cells, lynphocytes and chamber coatings

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Ground-based electrokinetic data on the electrophoresis flight experiment to be flown on the Apollo-Soyuz Test Project experiment MA-011 are stipulated. Aldehyde-fixed red blood cells, embryonic kidney cells and lymphocytes were evaluated by analytical particle electrophoresis. The results which aided in the interpretation of the final analysis of the MA-011 experiment are documented. The electrophoresis chamber surface modifications, the buffer, and the material used in the column system are also discussed.

  3. An enzyme-linked immunoabsorbent assay for estimating red cell survival of transfused red cells-validation using CR-51 labeling

    SciTech Connect

    Drew, H.; Kickler, T.; Smith, B.; LaFrance, N.

    1984-01-01

    The survival time of transfused red cells antigenically distinct from the recipient's red cells was determined using an indirect enzyme linked antiglobulin test. These results were then compared to those determined by Cr-51 labeling. Three patients with hypoproliferative anemias and one patient (2 studies) with traumatic hemolytic anemia caused by a prosthetic heart valve were studied. Survival times were performed by transfusing a 5cc aliquot of Cr-51 labeled cells along with the remaining unit. One hour post transfusion, a blood sample was drawn and used as the 100% value. Subsequent samples drawn over a 2-3 week period were then compared to the initial sample to determine percent survival for both methods. The ELISA method for measuring red cell survival in antigenically distinct cells is in close agreement with the Cr-51 method. Although CR-51 labeling is the accepted method for red cell survival determination the ELISA method can be used when radioisotopes are unavailable or contraindicated or when the decision to estimate red cell survival is made after transfusion.

  4. Influence of red cell concentration on filtration of blood cell suspensions.

    PubMed

    Schmalzer, E A; Skalak, R; Usami, S; Vayo, M; Chien, S

    1983-01-01

    Pressure-time curves obtained by passing suspensions of blood cells in Ringer solution through a 5 microns polycarbonate filter at constant flow (1.6 ml/min) were evaluated for their ability to reflect the deformability of the erythrocytes. The initial pressure reading (Pi) obtained in a quasi-steady state during the first 1-2 sec of pumping was found to be reproducible for hematocrit values between 10 and 30 percent. This Pi value was normalized by the pressure generated by the cell-free suspending medium (PO) at the same flow rate. The ratio Pi/PO was found to be linearly proportional to hematocrit up to 30 percent but independent of leukocyte concentration up to 12,000/mm3. Later portions of the curve did vary with leukocyte count. By using the equations developed from theoretical modeling of cells passing through a filter, the experimentally determined relation of Pi/PO to hematocrit, and the known geometry of the filter pores, we were able to calculate parameters reflecting the deformability of red cells. These include beta, the ratio of resistance in a pore containing a red cell to that in a pore containing only the suspending medium, and alpha, the proportion of pores filled by erythrocytes in transit. The application of theoretical analysis to experimental data has provided quantitative insights into the behavior of red cells during filtration tests in normal and disease states. PMID:6871424

  5. Automated analysis of 3D morphology of human red blood cells via off-axis digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Moon, Inkyu

    2013-05-01

    In this paper we overview an automated method for the analysis of clinical parameters of human red blood cells (RBCs). The digital holograms of mature RBCs are recorded by CCD camera with off-axis interferometry setup and the quantitative phase images of RBCs are formed by a numerical reconstruction technique. For automated investigation of the 3D morphology and mean corpuscular hemoglobin of RBCs, the unnecessary background in the RBCs phase images are removed by marker-controlled watershed segmentation algorithm. Then, characteristic properties of each RBC such as projected cell surface, average phase, mean corpuscular hemoglobin (MCH) and (MCH) surface density is quantitatively measured. Finally, the equality of covariance matrixes and mean vectors of these features for different kinds of RBCs are experimentally analyzed using statistical test scheme. Results show that these characteristic parameters of RBCs can be used as feature pattern to discriminate between RBC populations that differ in shape and hemoglobin content.

  6. Discrimination of microorganisms and cells in tissue engineering by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Koch, Steffen; Dreiling, Marieke; Gutekunst, Matthias; Bolwien, Carsten; Thielecke, Hagen; Mertsching, Heike

    2009-07-01

    Sterility testing of cell or tissue cultures is an essential task in the fields of regenerative medicine and tissue engineering. Especially in case of Good manufacturing practice (GMP) of cell and tissue based transplants. We present a system based on a commercially available microscope equipped with a microfluidic cell that prepares the particles found in the solution for analysis. A Raman-spectrometer attachment optimized for non-destructive, rapid recording of Raman spectra, and a data acquisition and analysis tool for identification of the particles. Identification of critical particles like microorganisms via microscopic imaging and subsequent image analysis is carried out before micro-Raman analysis of those particles is then carried out with an excitation wavelength of 785 nm. However an automated image analysis of small particles from supernatant of biopsies on a filter chip with tiny holes is a difficult task. Especially for the discrimination of small particles like cell debris and bacteria, which have a quite similar range of size. Because of that particles in the supernatant and microorganisms have to be discriminated by means of Raman spectroscopy. We present here a Raman based method to discriminate between cells, microorganisms and particles in cell culture.

  7. Colloidal Properties of Nanoerythrosomes Derived from Bovine Red Blood Cells.

    PubMed

    Kuo, Yuan-Chia; Wu, Hsuan-Chen; Hoang, Dao; Bentley, William E; D'Souza, Warren D; Raghavan, Srinivasa R

    2016-01-12

    Liposomes are nanoscale containers that are typically synthesized from lipids using a high-shear process such as extrusion or sonication. While liposomes are extensively used in drug delivery, they do suffer from certain problems including limited colloidal stability and short circulation times in the body. As an alternative to liposomes, we explore a class of container structures derived from erythrocytes (red blood cells). The procedure involves emptying the inner contents of these cells (specifically hemoglobin) and resuspending the empty structures in buffer, followed by sonication. The resulting structures are termed nanoerythrosomes (NERs), i.e., they are membrane-covered nanoscale containers, much like liposomes. Cryo-transmission electron microscopy (cryo-TEM) and small-angle neutron scattering (SANS) are employed for the first time to study these NERs. The results reveal that the NERs are discrete spheres (∼110 nm diameter) with a unilamellar membrane of thickness ∼4.5 nm. Remarkably, the biconcave disc-like shape of erythrocytes is also exhibited by the NERs under hypertonic conditions. Moreover, unlike typical liposomes, NERs show excellent colloidal stability in both buffer as well as in serum at room temperature, and are also able to withstand freeze-thaw cycling. We have explored the potential for using NERs as colloidal vehicles for targeted delivery. Much like conventional liposomes, NER membranes can be decorated with fluorescent or other markers, solutes can be encapsulated in the cores of the NERs, and NERs can be targeted to specifically bind to mammalian cells. Our study shows that NERs are a promising and versatile class of nanostructures. NERs that are harvested from a patient's own blood and reconfigured for nanomedicine can potentially offer several benefits including biocompatibility, minimization of immune response, and extended circulation time in the body. PMID:26684218

  8. Measurement of the Red Blood Cell Distribution Width Improves the Risk Prediction in Cardiac Resynchronization Therapy

    PubMed Central

    Boros, András Mihály; Perge, Péter; Jenei, Zsigmond; Karády, Júlia; Zima, Endre; Molnár, Levente; Becker, Dávid; Gellér, László; Prohászka, Zoltán; Merkely, Béla; Széplaki, Gábor

    2016-01-01

    Objectives. Increases in red blood cell distribution width (RDW) and NT-proBNP (N-terminal pro-B-type natriuretic peptide) predict the mortality of chronic heart failure patients undergoing cardiac resynchronization therapy (CRT). It was hypothesized that RDW is independent of and possibly even superior to NT-proBNP from the aspect of long-term mortality prediction. Design. The blood counts and serum NT-proBNP levels of 134 patients undergoing CRT were measured. Multivariable Cox regression models were applied and reclassification analyses were performed. Results. After separate adjustment to the basic model of left bundle branch block, beta blocker therapy, and serum creatinine, both the RDW > 13.35% and NT-proBNP > 1975 pg/mL predicted the 5-year mortality (n = 57). In the final model including all variables, the RDW [HR = 2.49 (1.27–4.86); p = 0.008] remained a significant predictor, whereas the NT-proBNP [HR = 1.18 (0.93–3.51); p = 0.07] lost its predictive value. On addition of the RDW measurement, a 64% net reclassification improvement and a 3% integrated discrimination improvement were achieved over the NT-proBNP-adjusted basic model. Conclusions. Increased RDW levels accurately predict the long-term mortality of CRT patients independently of NT-proBNP. Reclassification analysis revealed that the RDW improves the risk stratification and could enhance the optimal patient selection for CRT. PMID:26903690

  9. Visual pattern discrimination by population retinal ganglion cells' activities during natural movie stimulation.

    PubMed

    Zhang, Ying-Ying; Wang, Ru-Bin; Pan, Xiao-Chuan; Gong, Hai-Qing; Liang, Pei-Ji

    2014-02-01

    In the visual system, neurons often fire in synchrony, and it is believed that synchronous activities of group neurons are more efficient than single cell response in transmitting neural signals to down-stream neurons. However, whether dynamic natural stimuli are encoded by dynamic spatiotemporal firing patterns of synchronous group neurons still needs to be investigated. In this paper we recorded the activities of population ganglion cells in bullfrog retina in response to time-varying natural images (natural scene movie) using multi-electrode arrays. In response to some different brief section pairs of the movie, synchronous groups of retinal ganglion cells (RGCs) fired with similar but different spike events. We attempted to discriminate the movie sections based on temporal firing patterns of single cells and spatiotemporal firing patterns of the synchronous groups of RGCs characterized by a measurement of subsequence distribution discrepancy. The discrimination performance was assessed by a classification method based on Support Vector Machines. Our results show that different movie sections of the natural movie elicited reliable dynamic spatiotemporal activity patterns of the synchronous RGCs, which are more efficient in discriminating different movie sections than the temporal patterns of the single cells' spike events. These results suggest that, during natural vision, the down-stream neurons may decode the visual information from the dynamic spatiotemporal patterns of the synchronous group of RGCs' activities. PMID:24465283

  10. Neonatal nucleated red blood cells in G6PD deficiency.

    PubMed

    Yeruchimovich, Mark; Shapira, Boris; Mimouni, Francis B; Dollberg, Shaul

    2002-05-01

    The objective of this study is to study the absolute number of nucleated red blood cells (RBC) at birth, an index of active fetal erythropoiesis, in infants with G6PD deficiency and in controls. We tested the hypothesis that hematocrit and hemoglobin would be lower, and absolute nucleated RBC counts higher, in the G6PD deficient and that these changes would be more prominent in infants exposed passively to fava bean through maternal diet. Thirty-two term infants with G6PD deficiency were compared with 30 term controls. Complete blood counts with manual differential counts were obtained within 12 hours of life. Absolute nucleated RBC and corrected leukocyte counts were computed from the Coulter results and the differential count. G6PD deficient patients did not differ from controls in terms of gestational age, birth weight, or Apgar scores or in any of the hematologic parameters studied, whether or not the mother reported fava beans consumption in the days prior to delivery. Although intrauterine hemolysis is possible in G6PD deficient fetuses exposed passively to fava beans, our study supports that such events must be very rare. PMID:12012283

  11. Characterization of Red Blood Cells with Multiwavelength Transmission Spectroscopy

    PubMed Central

    Serebrennikova, Yulia M.; Huffman, Debra E.; Garcia-Rubio, Luis H.

    2015-01-01

    Multiwavelength transmission (MWT) spectroscopy was applied to the investigation of the morphological parameters and composition of red blood cells (RBCs). The MWT spectra were quantitatively analyzed with a Mie theory based interpretation model modified to incorporate the effects of the nonsphericity and orientation of RBCs. The MWT spectra of the healthy and anemic samples were investigated for the RBC indices in open and blinded studies. When MWT performance was evaluated against a standard reference system, very good agreement between two methods, with R2 > 0.85 for all indices studied, was demonstrated. The RBC morphological parameters were used to characterize three types of anemia and to draw an association between RBC morphology and anemia severity. The MWT spectra of RBCs infected with malaria parasite Plasmodium falciparum at different life cycle stages were analyzed for RBC morphological parameters. The changes in the RBC volume, surface area, aspect ratio, and hemoglobin composition were used to trace the morphological and compositional alterations in the infected RBCs occurring with parasites' development and to provide insights into parasite-host interactions. The MWT method was shown to be reliable for determination of the RBC morphological parameters and to be valuable for identification of the RBC pathologic changes and disease states. PMID:25654099

  12. Characterization of red blood cells with multiwavelength transmission spectroscopy.

    PubMed

    Serebrennikova, Yulia M; Huffman, Debra E; Garcia-Rubio, Luis H

    2015-01-01

    Multiwavelength transmission (MWT) spectroscopy was applied to the investigation of the morphological parameters and composition of red blood cells (RBCs). The MWT spectra were quantitatively analyzed with a Mie theory based interpretation model modified to incorporate the effects of the nonsphericity and orientation of RBCs. The MWT spectra of the healthy and anemic samples were investigated for the RBC indices in open and blinded studies. When MWT performance was evaluated against a standard reference system, very good agreement between two methods, with R (2) > 0.85 for all indices studied, was demonstrated. The RBC morphological parameters were used to characterize three types of anemia and to draw an association between RBC morphology and anemia severity. The MWT spectra of RBCs infected with malaria parasite Plasmodium falciparum at different life cycle stages were analyzed for RBC morphological parameters. The changes in the RBC volume, surface area, aspect ratio, and hemoglobin composition were used to trace the morphological and compositional alterations in the infected RBCs occurring with parasites' development and to provide insights into parasite-host interactions. The MWT method was shown to be reliable for determination of the RBC morphological parameters and to be valuable for identification of the RBC pathologic changes and disease states. PMID:25654099

  13. Ratio of Spleen Diameter to Red Blood Cell Distribution Width

    PubMed Central

    Balaban, Daniel Vasile; Popp, Alina; Lungu, Andrei Marian; Costache, Raluca Simona; Anca, Ioana Alina; Jinga, Mariana

    2015-01-01

    Abstract Celiac disease (CD) is currently considerably underdiagnosed, setting the need for developing tools to select patients with probability of CD, who warrant further testing. Red blood cell distribution width (RDW) has been shown in previous studies to be a sensitive predictor for CD, but it lacks specificity. Splenic hypotrophy is also noted frequently in celiac patients. Our aim was to evaluate if spleen diameter to RDW ratio can be used as an indicator for CD. We evaluated 15 newly diagnosed CD patients, 52 patients with inflammatory bowel disease, and 35 patients with irritable bowel syndrome (IBS). We evaluated the differences in spleen diameter, RDW, and their ratio among the four groups. Two-thirds of the CD patients had elevated RDW, compared to 9% in the IBS group. A small spleen was seen in 80% of the celiacs, compared to 21.9% in the ulcerative colitis group, 10% in the Crohn disease group, and 9% in the IBS group. A spleen diameter to RDW ratio under 6 had a sensitivity of 73.3% and specificity of 88.5% in predicting CD, with an AUROC of 0.737. Spleen diameter to RDW ratio is a simple, widely available score, which can be used to select adult patients with probability of CD. PMID:25881851

  14. Red Blood Cell Dysfunction Induced by High-Fat Diet

    PubMed Central

    Unruh, Dusten; Srinivasan, Ramprasad; Benson, Tyler; Haigh, Stephen; Coyle, Danielle; Batra, Neil; Keil, Ryan; Sturm, Robert; Blanco, Victor; Palascak, Mary; Franco, Robert S.; Tong, Wilson; Chatterjee, Tapan; Hui, David Y.; Davidson, W. Sean; Aronow, Bruce J.; Kalfa, Theodosia; Manka, David; Peairs, Abigail; Blomkalns, Andra; Fulton, David J.; Brittain, Julia E.; Weintraub, Neal L.; Bogdanov, Vladimir Y.

    2015-01-01

    Background High-fat diet (HFD) promotes endothelial dysfunction and proinflammatory monocyte activation, which contribute to atherosclerosis in obesity. We investigated whether HFD also induces the dysfunction of red blood cells (RBCs), which serve as a reservoir for chemokines via binding to Duffy antigen receptor for chemokines (DARC). Methods and Results A 60% HFD for 12 weeks, which produced only minor changes in lipid profile in C57/BL6 mice, markedly augmented the levels of monocyte chemoattractant protein-1 bound to RBCs, which in turn stimulated macrophage migration through an endothelial monolayer. Levels of RBC-bound KC were also increased by HFD. These effects of HFD were abolished in DARC−/− mice. In RBCs from HFD-fed wild-type and DARC−/− mice, levels of membrane cholesterol and phosphatidylserine externalization were increased, fostering RBC-macrophage inflammatory interactions and promoting macrophage phagocytosis in vitro. When labeled ex vivo and injected into wild-type mice, RBCs from HFD-fed mice exhibited ≈3-fold increase in splenic uptake. Finally, RBCs from HFD-fed mice induced increased macrophage adhesion to the endothelium when they were incubated with isolated aortic segments, indicating endothelial activation. Conclusions RBC dysfunction, analogous to endothelial dysfunction, occurs early during diet-induced obesity and may serve as a mediator of atherosclerosis. These findings may have implications for the pathogenesis of atherosclerosis in obesity, a worldwide epidemic. PMID:26467254

  15. Alteration of red blood cell aggregation during blood storage

    NASA Astrophysics Data System (ADS)

    Lim, Hyun-Jung; Nam, Jeong-Hun; Lee, Byoung-Kwon; Suh, Jang-Soo; Shin, Sehyun

    2011-06-01

    Even though the trade-off between the benefits and risks of blood transfusion has been discussed for the last several decades, it requires further understanding of the rheological changes in stored blood that include the alteration of red blood cell (RBC) aggregation. The RBC aggregation of stored blood in its autologous plasma was monitored through the storage period (35 days). The critical shear stress, as a measure of RBC aggregation, was determined by using a microfluidic aggregometer. Blood was processed into a blood bag containing the anticoagulant CPDA1 and stored at 4°C. It was subjected to assays after zero, seven, 14, and 35 days. The critical shear stress for stored blood did not change up to 14 days of storage but exhibited a significant decrease after 35 days of storage. These results were identical to those of the conventional aggregation index (AI). Also, in the alteration of RBC aggregation for blood storage, the effect of the plasma factor was slightly stronger than that of the cellular factor. Through the present study, the critical shear stress as a new measure of RBC aggregation may help to monitor and control the quality of blood storage.

  16. Harmless Pregnancy-Induced Warm Autoantibodies to Red Blood Cells

    PubMed Central

    Sürücü, Gülüstan; Mayer, Beate; Märzacker, Anneliese; Yürek, Salih; Salama, Abdulgabar

    2015-01-01

    Summary Background There is little information concerning the development and significance of autoantibodies (aab) to red blood cells (RBCs) during pregnancy. Methods Unselected pregnant women were routinely screened for the presence of unexpected antibodies to RBCs using standard techniques. Results Between 2009 and 2013, 153,612 pregnant women were tested. The antibody screening test was positive in 1,721 women (1.12%). In 1,602 (1.04%) cases, immune and/or non-immune alloantibodies and cold-reactive aab were detected, whereas warm-reactive aab were found in 119 women (0.08%). In almost all cases, warm-reactive aab belonged to the IgG class. No evidence of the presence of significant haemolysis in affected women was observed. Conclusion Pregnant women may rarely develop aab to RBCs, which do not appear to cause haemolytic anaemia. Further clarification is required on the reasons behind the development of these aab and their clinical insignificance. PMID:26696801

  17. Continuum modeling of deformation and aggregation of red blood cells.

    PubMed

    Yoon, Daegeun; You, Donghyun

    2016-07-26

    In order to gain better understanding for rheology of an isolated red blood cell (RBC) and a group of multiple RBCs, new continuum models for describing mechanical properties of cellular structures of an RBC and inter-cellular interactions among multiple RBCs are developed. The viscous property of an RBC membrane, which characterizes dynamic behaviors of an RBC under stress loading and unloading processes, is determined using a generalized Maxwell model. The present model is capable of predicting stress relaxation and stress-strain hysteresis, of which prediction is not possible using the commonly used Kelvin-Voigt model. Nonlinear elasticity of an RBC is determined using the Yeoh hyperelastic material model in a framework of continuum mechanics using finite-element approximation. A novel method to model inter-cellular interactions among multiple adjacent RBCs is also developed. Unlike the previous modeling approaches for aggregation of RBCs, where interaction energy for aggregation is curve-fitted using a Morse-type potential function, the interaction energy is analytically determined. The present aggregation model, therefore, allows us to predict various effects of physical parameters such as the osmotic pressure, the thickness of a glycocalyx layer, the penetration depth, and the permittivity, on the depletion and electrostatic energy among RBCs. Simulations for elongation and recovery deformation of an RBC and for aggregation of multiple RBCs are conducted to evaluate the efficacy of the present continuum modeling methods. PMID:26706720

  18. Interactions between earthworm hemolysins and sheep red blood cell membranes.

    PubMed

    Roch, P; Canicatti, C; Valembois, P

    1989-08-01

    The hemolytic activity exhibited by the coelomic fluid of the Annelid Eisenia fetida andrei is mediated by two lipoproteins of mass 40 and 45 kDa, each of them capable of hemolysis. Such an activity is not inhibited by zymosan, inulin or lipopolysaccharide (LPS), nor by hydrazine or methylamine, suggesting that earthworm hemolysins are not related to C3 or C3b complement components. Among the membrane lipids tested (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingomyelin and cholesterol) only sphingomyelin inhibited hemolysis. The analysis of E.f. andrei proteins bound to sphingomyelin microvesicles, as well as to sheep red blood cell (SRBC) membranes, revealed a polymerization of E.f. andrei 40 kDa and/or 45 kDa hemolysins. Consequently, sphingomyelin appears a likely candidate for hemolytic complex receptor. Electron microscopy observations suggested that the polymerization causes an open channel through the lipid bilayer. As demonstrated using metal ions, heparin, chondroitin sulfate, poly(L-lysine) and protamine chloride, the mode of action of earthworm hemolytic complex is not analogous to that of C9 or perforine. PMID:2758056

  19. Perioperative Red Blood Cell Transfusion: What We Do Not Know

    PubMed Central

    Lei, Chong; Xiong, Li-Ze

    2015-01-01

    Objective: Blood transfusion saves lives but may also increase the risk of injury. The objective of this review was to evaluate the possible adverse effects related to transfusion of red blood cell (RBC) concentrates stored for prolonged periods. Data Sources: The data used in this review were mainly from PubMed articles published in English up to February 2015. Study Selection: Clinical and basic research articles were selected according to their relevance to this topic. Results: The ex vivo changes to RBC that occur during storage are collectively called storage lesion. It is still inconclusive if transfusion of RBC with storage lesion has clinical relevance. Multiple ongoing prospective randomized controlled trials are aimed to clarify this clinical issue. It was observed that the adverse events related to stored RBC transfusion were prominent in certain patient populations, including trauma, critical care, pediatric, and cardiac surgery patients, which leads to the investigation of underlying mechanisms. It is demonstrated that free hemoglobin toxicity, decreasing of nitric oxide bioavailability, and free iron-induced increasing of inflammation may play an important role in this process. Conclusion: It is still unclear whether transfusion of older RBC has adverse effects, and if so, which factors determine such clinical effects. However, considering the magnitude of transfusion and the widespread medical significance, potential preventive strategies should be considered, especially for the susceptible recipients. PMID:26315088

  20. Red blood cell deformability in diabetes mellitus: effect of phytomenadione.

    PubMed

    Sabo, A; Jakovljević, V; Stanulović, M; Lepsanović, L; Pejin, D

    1993-01-01

    Decreased deformability of red blood cells (RBC) in diabetes mellitus (DM) is considered to be linked to microcirculatory complications in this condition. As we found that phytomenadione increased RBC deformability in experimental animals, the question was raised, whether phytomenadione had the same effect on the RBC of diabetic patients. The study was performed in 10 patients with insulin-dependent diabetes mellitus, where the erythrocyte deformability was impaired. Patients received 10 mg/day phytomenadione i.m. for five days. Deformability was measured with policarbonate membranes (Nucleopore) with pore diameter 5 microns, under gravity. The results were expressed as the ratio (r) between the flow of 1.5 ml (r1) and 2 ml (r2) of RBC suspension and 1.5 ml of buffer. Phytomenadione increased the erythrocyte deformability in patients with diabetes mellitus, lowering the value r1 from 3.54 +/- 0.84 to 2.32 +/- 0.61 (p 0.02) and r2 from 7.80 +/- 2.41 to 4.65 +/- 1.07 (p 0.01). The values after treatment reached the range of healthy controls (r1 3.11 +/- 0.98, r2 6.52 +/- 3.04). The whole blood viscosity was significantly lowered after phytomenadione (5.28 +/- 0.58 mPas before, 4.64 +/- 0.74 mPas after, p < 0.02) with unchanged plasma viscosity, but significantly lowered internal viscosity of erythrocytes. PMID:8444511

  1. Procoagulant activity in stored units of red blood cells.

    PubMed

    Aleshnick, Maya; Foley, Jonathan H; Keating, Friederike K; Butenas, Saulius

    2016-06-10

    The procoagulant activity (PA) of stored units of red blood cells (RBC) increases over time, which is related to the expression/exposure of tissue factor (TF). However, there is a discrepancy between the TF measured and changes in PA observed, suggesting that other blood components contribute to this activity. Our goal was to evaluate changes in PA of stored RBCs and to determine possible contributors to it. RBC units from 4 healthy donors were prepared and stored at 4 °C. On selected days, RBC aliquots were reconstituted with autologous plasma and tested in the thromboelastography assay. Corresponding supernatants were tested in a clotting assay. For all donors, the clotting time (CT) of reconstituted RBC units decreased from ∼3000-4000s on day 1 to ∼1000-1600s on day 30, with the most dramatic changes occurring between days 1 and 5. Anti-TF antibody slightly prolonged the CT. The concentration of TF did not change significantly over time and was within the range of 0.3-2.3 pM. Bovine lactadherin (LTD) prolonged the CT of the RBC (by 2.4-3.4-fold in days 3-5 and by 1.3-1.8-fold at day 30). Anti-TF antibody together with LTD had a cumulative effect on the CT prolongation. CT of supernatants responded to both anti-TF and anti-FXIa antibodies. Three contributors to the PA of stored RBC were identified, i.e. FXIa in solution and phosphatidylserine and TF exposed on blood cells and microparticles. Failure of LTD and antibodies to completely eliminate PA suggests that other components of blood could contribute to it. PMID:27150627

  2. Use of indium-111 as a red cell label

    SciTech Connect

    AuBuchon, J.P.; Brightman, A.

    1989-02-01

    To select the most promising 111In chelate for use as a second red cell (RBC) label for comparison of the survival of autologous and allogeneic cells, 49 normal RBC samples were studied in vitro after being labeled with 111In-8-hydroxyquinolinol (111In-oxine) prepared by three different methods, 111In-tropolone, and 111In-acetylacetone. Labeling efficiencies reached 99 percent and did not decline when the amount of 111In used was increased from 1.75 to 50 muCi per ml of RBCs. Storage of labeled RBCs in normal AB plasma at 4, 22, and 37 degrees C for up to 48 hours resulted in a similar rate of loss of the label from the RBCs with all labeling methods. These rates were time- and temperature-dependent and were accurate predictions of the rates found in later in vivo experimentation. Fresh RBCs from 11 subjects were labeled with 111In chelated with oxine in the presence of the RBCs or chelated with tropolone just prior to the labeling. RBC mass determinations using these autologous RBCs labeled with 111In accurately reflected the subjects' RBC masses as predicted through standard morphometric formulae. The rate of disappearance of the radionuclide after reinfusion of the autologous RBCs decreased with time. At 24 hours after reinfusion, 89.5 +/- 1.29 percent (mean +/- SEM) of the 111In-tropolone and 87.3 +/- 1.25 percent of the 111In-oxine continued in circulation. 111In is a simple and efficient agent for the labeling of RBCs for blood volume determinations and short-term survivals.

  3. Measuring red blood cell aggregation forces using double optical tweezers.

    PubMed

    Fernandes, Heloise P; Fontes, Adriana; Thomaz, André; Castro, Vagner; Cesar, Carlos L; Barjas-Castro, Maria L

    2013-04-01

    Classic immunohematology approaches, based on agglutination techniques, have been used in manual and automated immunohematology laboratory routines. Red blood cell (RBC) agglutination depends on intermolecular attractive forces (hydrophobic bonds, Van der Walls, electrostatic forces and hydrogen bonds) and repulsive interactions (zeta potential). The aim of this study was to measure the force involved in RBC aggregation using double optical tweezers, in normal serum, in the presence of erythrocyte antibodies and associated to agglutination potentiator solutions (Dextran, low ionic strength solution [LISS] and enzymes). The optical tweezers consisted of a neodymium:yattrium aluminium garnet (Nd:YAG) laser beam focused through a microscope equipped with a minicam, which registered the trapped cell image in a computer where they could be analyzed using a software. For measuring RBC aggregation, a silica bead attached to RBCs was trapped and the force needed to slide one RBC over the other, as a function of the velocities, was determined. The median of the RBC aggregation force measured in normal serum (control) was 1 × 10(-3) (0.1-2.5) poise.cm. The samples analyzed with anti-D showed 2 × 10(-3) (1.0-4.0) poise.cm (p < 0.001). RBC diluted in potentiator solutions (Dextran 0.15%, Bromelain and LISS) in the absence of erythrocyte antibodies, did not present agglutination. High adherence was observed when RBCs were treated with papain. Results are in agreement with the imunohematological routine, in which non-specific results are not observed when using LISS, Dextran and Bromelain. Nevertheless, false positive results are frequently observed in manual and automated microplate analyzer using papain enzyme. The methodology proposed is simple and could provide specific information with the possibility of meansuration regarding RBC interaction. PMID:23402665

  4. Rapid and quantitative discrimination of tumour cells on tissue slices

    NASA Astrophysics Data System (ADS)

    Huang, Kai-Wen; Chieh, Jen-Jie; Liao, Shu-Hsien; Wei, Wen-Chun; Hsiao, Pei-Yi; Yang, Hong-Chang; Horng, Herng-Er

    2016-06-01

    After a needle biopsy, immunohistochemistry is generally used to stain tissue slices for clinically confirming tumours. Currently, tissue slices are immersed in a bioprobe-linked fluorescent reagent for several minutes, washed to remove the unbound reagent, and then observed using a fluorescence microscope. However, the observation must be performed by experienced pathologists, and producing a qualitative analysis is time consuming. Therefore, this study proposes a novel scanning superconducting quantum interference device biosusceptometry (SSB) method for avoiding these drawbacks. First, stain reagents were synthesised for the dual modalities of fluorescent and magnetic imaging by combining iron-oxide magnetic nanoparticles and the currently used fluorescent reagent. The reagent for the proposed approach was stained using the same procedure as that for the current fluorescent reagent, and tissue slices were rapidly imaged using the developed SSB for obtaining coregistered optical and magnetic images. Analysing the total intensity of magnetic spots in SSB images enables quantitatively determining the tumour cells of tissue slices. To confirm the magnetic imaging results, a traditional observation methodology entailing the use of a fluorescence microscope was also performed as the gold standard. This study determined high consistency between the fluorescent and magnetic spots in different regions of the tissue slices, demonstrating the feasibility of the proposed approach, which will benefit future clinical pathology.

  5. Rapid and quantitative discrimination of tumour cells on tissue slices.

    PubMed

    Huang, Kai-Wen; Chieh, Jen-Jie; Liao, Shu-Hsien; Wei, Wen-Chun; Hsiao, Pei-Yi; Yang, Hong-Chang; Horng, Herng-Er

    2016-06-10

    After a needle biopsy, immunohistochemistry is generally used to stain tissue slices for clinically confirming tumours. Currently, tissue slices are immersed in a bioprobe-linked fluorescent reagent for several minutes, washed to remove the unbound reagent, and then observed using a fluorescence microscope. However, the observation must be performed by experienced pathologists, and producing a qualitative analysis is time consuming. Therefore, this study proposes a novel scanning superconducting quantum interference device biosusceptometry (SSB) method for avoiding these drawbacks. First, stain reagents were synthesised for the dual modalities of fluorescent and magnetic imaging by combining iron-oxide magnetic nanoparticles and the currently used fluorescent reagent. The reagent for the proposed approach was stained using the same procedure as that for the current fluorescent reagent, and tissue slices were rapidly imaged using the developed SSB for obtaining coregistered optical and magnetic images. Analysing the total intensity of magnetic spots in SSB images enables quantitatively determining the tumour cells of tissue slices. To confirm the magnetic imaging results, a traditional observation methodology entailing the use of a fluorescence microscope was also performed as the gold standard. This study determined high consistency between the fluorescent and magnetic spots in different regions of the tissue slices, demonstrating the feasibility of the proposed approach, which will benefit future clinical pathology. PMID:27138705

  6. Perturbation of red blood cell flow in small tubes by white blood cells.

    PubMed

    Thompson, T N; La Celle, P L; Cokelet, G R

    1989-02-01

    The flow of blood in the microcirculation is facilitated by the dynamic reduction in viscosity (Fahraeus-Lindquist effect) resulting from the axial flow of deforming erythrocytes (RBCs) and from the decrease in the ratio of cell to vessel diameter. RBC velocity exceeds that of average fluid velocity; however the slower moving white blood cells (WBC) perturb flow velocity and the ratio of cell to vessel diameter by obstructing red cell flow through formation of "trains" of red cells collecting behind the white cell. This effect of white cells was studied quantitatively in a model in vitro tubes less than 10 microns in diameter with the demonstration that flow resistance increases linearly with white cell numbers up to 1,000 WBC/mm3 at tube hematocrit of 17.7%. The increase in resistance exceeds the flow resistance of WBC and appears to relate directly to train formation. A mechanical model of train formation developed to predict WBC influence in flow resistance over the range of WBC studied reasonably fits observed WBC effects. PMID:2928089

  7. Effects of Poloxamer 188 on red blood cell membrane properties in sickle cell anaemia.

    PubMed

    Sandor, Barbara; Marin, Mickaël; Lapoumeroulie, Claudine; Rabaï, Miklos; Lefevre, Sophie D; Lemonne, Nathalie; El Nemer, Wassim; Mozar, Anaïs; Français, Olivier; Le Pioufle, Bruno; Connes, Philippe; Le Van Kim, Caroline

    2016-04-01

    Vaso-occlusive crisis (VOC) is the main acute complication in sickle cell anaemia (SS) and several clinical trials are investigating different drugs to improve the clinical severity of SS patients. A phase III study is currently exploring the profit of Velopoloxamer in SS during VOCs. We analysed, in-vitro, the effect of poloxamer (P188) on red blood cell (RBC) properties by investigating haemorheology, mechanical and adhesion functions using ektacytometry, microfluidics and dynamic adhesion approaches, respectively. We show that poloxamer significantly reduces blood viscosity, RBC aggregation and adhesion to endothelial cells, supporting the beneficial use of this molecule in SS therapy. PMID:26846309

  8. Membrane characteristics and osmotic fragility of red cells, fractionated with anglehead centrifugation and counterflow centrifugation.

    PubMed

    van der Vegt, S G; Ruben, A M; Werre, J M; de Gier, J; Staal, G E

    1985-11-01

    Red cell populations were separated on the basis of differences in density using anglehead centrifugation and on the basis of differences in mean cell volume using counterflow centrifugation. In the different fractions, mean surface area was calculated, phospholipid and cholesterol content determined as well as the osmotic behaviour in hypotonic salt solutions. Older red cells appeared to be more resistant to hypotonic salt solutions, due to favourable surface area to volume ratio. PMID:4063204

  9. Three-dimensional counting of morphologically normal human red blood cells via digital holographic microscopy

    NASA Astrophysics Data System (ADS)

    Yi, Faliu; Moon, Inkyu; Lee, Yeon H.

    2015-01-01

    Counting morphologically normal cells in human red blood cells (RBCs) is extremely beneficial in the health care field. We propose a three-dimensional (3-D) classification method of automatically determining the morphologically normal RBCs in the phase image of multiple human RBCs that are obtained by off-axis digital holographic microscopy (DHM). The RBC holograms are first recorded by DHM, and then the phase images of multiple RBCs are reconstructed by a computational numerical algorithm. To design the classifier, the three typical RBC shapes, which are stomatocyte, discocyte, and echinocyte, are used for training and testing. Nonmain or abnormal RBC shapes different from the three normal shapes are defined as the fourth category. Ten features, including projected surface area, average phase value, mean corpuscular hemoglobin, perimeter, mean corpuscular hemoglobin surface density, circularity, mean phase of center part, sphericity coefficient, elongation, and pallor, are extracted from each RBC after segmenting the reconstructed phase images by using a watershed transform algorithm. Moreover, four additional properties, such as projected surface area, perimeter, average phase value, and elongation, are measured from the inner part of each cell, which can give significant information beyond the previous 10 features for the separation of the RBC groups; these are verified in the experiment by the statistical method of Hotelling's T-square test. We also apply the principal component analysis algorithm to reduce the dimension number of variables and establish the Gaussian mixture densities using the projected data with the first eight principal components. Consequently, the Gaussian mixtures are used to design the discriminant functions based on Bayesian decision theory. To improve the performance of the Bayes classifier and the accuracy of estimation of its error rate, the leaving-one-out technique is applied. Experimental results show that the proposed method can

  10. Marked increase of calcium uptake in the ATP-depleted red cells of patients with iron deficiency

    SciTech Connect

    Shimoda, M.; Yawata, Y.

    1985-05-01

    Calcium (Ca) uptake was markedly increased in ATP-depleted red cells of patients with iron deficiency anemia (IDA) compared to ATP- depleted normal red cells. The extent of increased Ca uptake was related to the severity of iron deficiency as judged by decreased mean cell volume. Moreover, the increased Ca uptake returned to normal levels after oral iron supplementation therapy. The net calcium content of fresh red cells from iron-deficient individuals was the same as in red cells from normal subjects. Sodium influx and ferric ion uptake appeared to be virtually unaffected in the iron deficient red cells.

  11. Pheromone discrimination ability of olfactory bulb mitral and ruffed cells in the goldfish (Carassius auratus).

    PubMed

    Zippel, H P; Gloger, M; Lüthje, L; Nasser, S; Wilcke, S

    2000-06-01

    Significant anatomical differences characterizing mitral cells and ruffed cells were published by Kosaka and Hama in three teleost species. Physiological responses from both types of relay neurons have now been recorded extracellularly and simultaneously in the plexiform layer using a single tungsten microelectrode. During interstimulus intervals mitral cells responded with higher, frequently burst-like impulse rates triggered by the activity of epithelial receptor neurons. Ruffed cell impulse rates were low, and each action potential triggered a long-lasting, continuously variable, integrated granule cell potential. During olfactory stimulation with important biological stimuli such as preovulatory and ovulatory pheromones, a probable alarm pheromone and amino acids contrasting interactions between mitral cells and ruffed cells resulting in a drastic intensification of centrally transmitted information were frequently recorded. Individual neurons excellently discriminated stimuli. Irrespective of the physiological relevance of stimuli, however, similarities were recorded in the distribution of excitatory, inhibitory and indifferent responses. PMID:10866992

  12. Tc-99m-labeled red blood cells for the measurement of red cell mass in newborn infants: concise communication

    SciTech Connect

    Linderkamp, O.; Betke, K.; Fendel, H.; Klemm, J.; Lorenzen, K.; Riegel, K.P.

    1980-07-01

    In vitro and in vivo investigations were performed to examine the binding of Tc-99m to neonatal red blood cells (RBC). Labeling efficiency was about 90%, and unbound Tc-99m less than 3% after one washing, in premature and full-term newborns and in children. Thus presence of high percentages of fetal hemoglobin (Hb F) did not influence the labeling of RBCs with Tc-99m. RBCs of 11 newborns were hemolysed and the distribution of Tc-99m on RBC components was analyzed. Although Hb F percentage averaged (60.0 +- 8.10)% (s.d.), only (11.9 +- 3.7)% of Tc-99m was bound by Hb F, whereas (45.0 +- 6.1)% was associated with Hb A. RBC membranes bound (13.7 +- 4.3)% and (29.3 +- 4.0)% were found unbound in hemolysates. These results indicate that Tc-99m preferentially binds to beta chains. In vivo equilibration of Tc-99m RBCs and of albumin labeled with Evans blue was investigated in five newborn infants. Tc-99m RBCs were stable in each case during the first hour after injection. Elution of Tc-99m from RBCs was (3.4 +- 1.5)% per h. Body-to-venous hematocrit ratio averaged 0.86 +- 0.03.

  13. Rheological properties of RBC in the microcirculation of mammalian skeletal muscle. [red blood cells

    NASA Technical Reports Server (NTRS)

    Ehrenberg, M. H.

    1974-01-01

    In the investigation the established technique of direct microscopic viewing was combined with the use of a closed circuit television system and cinematography. The red cell flow patterns in all capillaries were found to be oscillatory with characteristic cycle frequencies and amplitudes for all concentrations of inspired oxygen greater than 8%. Generally, there was a transient decrease in mean flow rate with increasing severity of hypoxia, with a gradual return toward control values. Red cell flow patterns are discussed along with questions of red cell configuration.

  14. The acute effects of nifedipine on red cell deformability in angina pectoris.

    PubMed Central

    Waller, D G; Nicholson, H P; Roath, S

    1984-01-01

    In a randomised double-blind study, the effects on red cell deformability of a single sublingual dose of nifedipine were compared with placebo in eight patients with stable angina pectoris. Red cell deformability, measured by filtration and centrifugation techniques, was significantly increased at rest in all eight patients 1 h after nifedipine, while no change occurred after placebo. The improvement in deformability after nifedipine was maintained at the end of a period of exercise and unchanged from resting values after placebo. The results suggest that the increased deformability of red cells after nifedipine could contribute to the therapeutic effects of the drug in myocardial ischaemia. PMID:6704282

  15. The energy-less red blood cell is lost: erythrocyte enzyme abnormalities of glycolysis.

    PubMed

    van Wijk, Richard; van Solinge, Wouter W

    2005-12-15

    The red blood cell depends solely on the anaerobic conversion of glucose by the Embden-Meyerhof pathway for the generation and storage of high-energy phosphates, which is necessary for the maintenance of a number of vital functions. Many red blood cell enzymopathies have been described that disturb the erythrocyte's integrity, shorten its cellular survival, and result in hemolytic anemia. By far the majority of these enzymopathies are hereditary in nature. In this review, we summarize the current knowledge regarding the genetic, biochemical, and structural features of clinically relevant red blood cell enzymopathies involved in the Embden-Meyerhof pathway and the Rapoport-Luebering shunt. PMID:16051738

  16. Detection of IgG sensitization of red cells with /sup 125/I staphylococcal protein A

    SciTech Connect

    Yam, P.; Petz, L.D.; Spath, P.

    1982-06-01

    Most cases of immune hemolytic anemia are associated with a positive direct antiglobulin test. However, in some cases, the antiglobulin test is not sensitive enough to detect low levels of red-cell bound antibodies. This report describes a method using radiolabelled purified staphylococcal protein A which is capable of detecting IgG sensitization of red cells beyond the threshold of serologic techniques. It is less cumbersome than previously described methods and does not require antibody purification procedures. Its effectiveness was demonstrated for the detection of red-cell alloantibodies and in evaluation of patients with acquired hemolytic anemias associated with a negative direct antiglobulin test.

  17. Erythropoietic Protoporphyria: Lipid Peroxidation and Red Cell Membrane Damage Associated with Photohemolysis

    PubMed Central

    Goldstein, Bernard D.; Harber, Leonard C.

    1972-01-01

    The mechanism by which long wavelength ultraviolet light hemolyzes red cells obtained from patients with erythropoietic protoporphyria (EPP) was investigated. Previous studies had suggested that irradiation of these red cells with wavelengths of light capable of eliciting dermatological manifestations led to oxygen-dependent colloid osmotic hemolysis through the formation of peroxides. In the present report, lipid peroxidation during in vitro irradiation of EPP red cells with long ultraviolet light was demonstrated by: (a) the formation of 2-thiobarbituric acid reactants; (b) the presence of conjugated diene bonds in red cell lipid; and (c) the selective loss of unsaturated fatty acids proportional to the number of carbon-carbon double bonds in each. Irradiation of EPP red cells was also shown to result in the formation of hydrogen peroxide. Before photohemolysis there was a decline in cell membrane sulfhydryl groups and a loss in activity of the cell membrane enzyme acetylcholinesterase. These parameters provide further evidence suggesting that the cell membrane is a primary site of the photohemolytic effect of long ultraviolet light in EPP red cells. Further evaluation of the radiation-induced inactivation of EPP red cell acetylcholinesterase was performed by radiating mixtures containing bovine erythrocyte acetylcholinesterase and protoporphyrin IX. These studies revealed that the rate of decline in enzyme activity is accelerated by the addition of linoleic acid, an unsaturated fatty acid, but not by palmitic acid, a saturated fatty acid. Partial protection against both photohemolysis and acetylcholinesterase decline is provided by alpha-to-copherol. This lipid antioxidant loses its activity during the irradiation of EPP red cells suggesting that it is utilized in this process. PMID:5014616

  18. Safe extension of red blood cell storage life at 4{degree}C

    SciTech Connect

    Bitensky, M.; Yoshida, Tatsuro

    1996-04-01

    The project sought to develop methods to extend the storage life of red blood cells. Extended storage would allow donor to self or autologous transfusion, expand and stabilize the blood supply, reduce the cost of medical care and eliminate the risk of transfusion related infections, including a spectrum of hepatitides (A, B and C) and HIV. The putative cause of red blood cell spoilage at 4 C has been identified as oxidative membrane damage resulting from deoxyhemoglobin and its denaturation products including hemichrome, hemin and Fe{sup 3+}. Trials with carbon monoxide, which is a stabilizer of hemoglobin, have produced striking improvement of red blood cell diagnostics for cells stored at 4 C. Carbonmonoxy hemoglobin is readily converted to oxyhemoglobin by light in the presence of oxygen. These findings have generated a working model and an approach to identify the best protocols for optimal red cell storage and hemoglobin regeneration.

  19. Sickle cell disease biochip: a functional red blood cell adhesion assay for monitoring sickle cell disease.

    PubMed

    Alapan, Yunus; Kim, Ceonne; Adhikari, Anima; Gray, Kayla E; Gurkan-Cavusoglu, Evren; Little, Jane A; Gurkan, Umut A

    2016-07-01

    Sickle cell disease (SCD) afflicts millions of people worldwide and is associated with considerable morbidity and mortality. Chronic and acute vaso-occlusion are the clinical hallmarks of SCD and can result in pain crisis, widespread organ damage, and early movtality. Even though the molecular underpinnings of SCD were identified more than 60 years ago, there are no molecular or biophysical markers of disease severity that are feasibly measured in the clinic. Abnormal cellular adhesion to vascular endothelium is at the root of vaso-occlusion. However, cellular adhesion is not currently evaluated clinically. Here, we present a clinically applicable microfluidic device (SCD biochip) that allows serial quantitative evaluation of red blood cell (RBC) adhesion to endothelium-associated protein-immobilized microchannels, in a closed and preprocessing-free system. With the SCD biochip, we have analyzed blood samples from more than 100 subjects and have shown associations between the measured RBC adhesion to endothelium-associated proteins (fibronectin and laminin) and individual RBC characteristics, including hemoglobin content, fetal hemoglobin concentration, plasma lactate dehydrogenase level, and reticulocyte count. The SCD biochip is a functional adhesion assay, reflecting quantitative evaluation of RBC adhesion, which could be used at baseline, during crises, relative to various long-term complications, and before and after therapeutic interventions. PMID:27063958

  20. Sickle cell disease biochip: a functional red blood cell adhesion assay for monitoring sickle cell disease

    PubMed Central

    ALAPAN, YUNUS; KIM, CEONNE; ADHIKARI, ANIMA; GRAY, KAYLA E.; GURKAN-CAVUSOGLU, EVREN; LITTLE, JANE A.; GURKAN, UMUT A.

    2016-01-01

    Sickle cell disease (SCD) afflicts millions of people worldwide and is associated with considerable morbidity and mortality. Chronic and acute vaso-occlusion are the clinical hallmarks of SCD and can result in pain crisis, widespread organ damage, and early movtality. Even though the molecular underpinnings of SCD were identified more than 60 years ago, there are no molecular or biophysical markers of disease severity that are feasibly measured in the clinic. Abnormal cellular adhesion to vascular endothelium is at the root of vaso-occlusion. However, cellular adhesion is not currently evaluated clinically. Here, we present a clinically applicable microfluidic device (SCD biochip) that allows serial quantitative evaluation of red blood cell (RBC) adhesion to endothelium-associated protein-immobilized microchannels, in a closed and preprocessing-free system. With the SCD biochip, we have analyzed blood samples from more than 100 subjects and have shown associations between the measured RBC adhesion to endothelium-associated proteins (fibronectin and laminin) and individual RBC characteristics, including hemoglobin content, fetal hemoglobin concentration, plasma lactate dehydrogenase level, and reticulocyte count. The SCD biochip is a functional adhesion assay, reflecting quantitative evaluation of RBC adhesion, which could be used at baseline, during crises, relative to various long-term complications, and before and after therapeutic interventions. PMID:27063958

  1. Isoelectric focusing of red blood cells in a density gradient stabilized column

    NASA Technical Reports Server (NTRS)

    Smolka, A. J. K.; Miller, T. Y.

    1980-01-01

    The effects of Ficoll and cell application pH on red blood cell electrophoretic mobility and focusing pH were investigated by focusing cells in a density gradient stabilized column. Sample loading, cell dispersion, column conductivity, resolution of separation, and the effect of Ampholines were examined.

  2. Red Cell Properties after Different Modes of Blood Transportation

    PubMed Central

    Makhro, Asya; Huisjes, Rick; Verhagen, Liesbeth P.; Mañú-Pereira, María del Mar; Llaudet-Planas, Esther; Petkova-Kirova, Polina; Wang, Jue; Eichler, Hermann; Bogdanova, Anna; van Wijk, Richard; Vives-Corrons, Joan-Lluís; Kaestner, Lars

    2016-01-01

    Transportation of blood samples is unavoidable for assessment of specific parameters in blood of patients with rare anemias, blood doping testing, or for research purposes. Despite the awareness that shipment may substantially alter multiple parameters, no study of that extent has been performed to assess these changes and optimize shipment conditions to reduce transportation-related artifacts. Here we investigate the changes in multiple parameters in blood of healthy donors over 72 h of simulated shipment conditions. Three different anticoagulants (K3EDTA, Sodium Heparin, and citrate-based CPDA) for two temperatures (4°C and room temperature) were tested to define the optimal transportation conditions. Parameters measured cover common cytology and biochemistry parameters (complete blood count, hematocrit, morphological examination), red blood cell (RBC) volume, ion content and density, membrane properties and stability (hemolysis, osmotic fragility, membrane heat stability, patch-clamp investigations, and formation of micro vesicles), Ca2+ handling, RBC metabolism, activity of numerous enzymes, and O2 transport capacity. Our findings indicate that individual sets of parameters may require different shipment settings (anticoagulants, temperature). Most of the parameters except for ion (Na+, K+, Ca2+) handling and, possibly, reticulocytes counts, tend to favor transportation at 4°C. Whereas plasma and intraerythrocytic Ca2+ cannot be accurately measured in the presence of chelators such as citrate and EDTA, the majority of Ca2+-dependent parameters are stabilized in CPDA samples. Even in blood samples from healthy donors transported using an optimized shipment protocol, the majority of parameters were stable within 24 h, a condition that may not hold for the samples of patients with rare anemias. This implies for as short as possible shipping using fast courier services to the closest expert laboratory at reach. Mobile laboratories or the travel of the patients to

  3. Vesiculation of healthy and defective red blood cells

    NASA Astrophysics Data System (ADS)

    Li, He; Lykotrafitis, George

    2015-07-01

    Vesiculation of mature red blood cells (RBCs) contributes to removal of defective patches of the erythrocyte membrane. In blood disorders, which are related to defects in proteins of the RBC membrane, vesiculation of the plasma membrane is intensified. Several hypotheses have been proposed to explain RBC vesiculation but the exact underlying mechanisms and what determines the sizes of the vesicles are still not completely understood. In this work, we apply a two-component coarse-grained molecular dynamics RBC membrane model to study how RBC vesiculation is controlled by the membrane spontaneous curvature and by lateral compression of the membrane. Our simulation results show that the formation of small homogeneous vesicles with a diameter less than 40 nm can be attributed to a large spontaneous curvature of membrane domains. On the other hand, compression on the membrane can cause the formation of vesicles with heterogeneous composition and with sizes comparable with the size of the cytoskeleton corral. When spontaneous curvature and lateral compression are simultaneously considered, the compression on the membrane tends to facilitate formation of vesicles originating from curved membrane domains. We also simulate vesiculation of RBCs with membrane defects connected to hereditary elliptocytosis (HE) and to hereditary spherocytosis (HS). When the vertical connectivity between the lipid bilayer and the membrane skeleton is elevated, as in normal RBCs, multiple vesicles are shed from the compressed membrane with diameters similar to the cytoskeleton corral size. In HS RBCs, where the connectivity between the lipid bilayer and the cytoskeleton is reduced, larger-size vesicles are released under the same compression ratio as in normal RBCs. Lastly, we find that vesicles released from HE RBCs can contain cytoskeletal filaments due to fragmentation of the membrane skeleton while vesicles released from the HS RBCs are depleted of cytoskeletal filaments.

  4. Red Cell Properties after Different Modes of Blood Transportation.

    PubMed

    Makhro, Asya; Huisjes, Rick; Verhagen, Liesbeth P; Mañú-Pereira, María Del Mar; Llaudet-Planas, Esther; Petkova-Kirova, Polina; Wang, Jue; Eichler, Hermann; Bogdanova, Anna; van Wijk, Richard; Vives-Corrons, Joan-Lluís; Kaestner, Lars

    2016-01-01

    Transportation of blood samples is unavoidable for assessment of specific parameters in blood of patients with rare anemias, blood doping testing, or for research purposes. Despite the awareness that shipment may substantially alter multiple parameters, no study of that extent has been performed to assess these changes and optimize shipment conditions to reduce transportation-related artifacts. Here we investigate the changes in multiple parameters in blood of healthy donors over 72 h of simulated shipment conditions. Three different anticoagulants (K3EDTA, Sodium Heparin, and citrate-based CPDA) for two temperatures (4°C and room temperature) were tested to define the optimal transportation conditions. Parameters measured cover common cytology and biochemistry parameters (complete blood count, hematocrit, morphological examination), red blood cell (RBC) volume, ion content and density, membrane properties and stability (hemolysis, osmotic fragility, membrane heat stability, patch-clamp investigations, and formation of micro vesicles), Ca(2+) handling, RBC metabolism, activity of numerous enzymes, and O2 transport capacity. Our findings indicate that individual sets of parameters may require different shipment settings (anticoagulants, temperature). Most of the parameters except for ion (Na(+), K(+), Ca(2+)) handling and, possibly, reticulocytes counts, tend to favor transportation at 4°C. Whereas plasma and intraerythrocytic Ca(2+) cannot be accurately measured in the presence of chelators such as citrate and EDTA, the majority of Ca(2+)-dependent parameters are stabilized in CPDA samples. Even in blood samples from healthy donors transported using an optimized shipment protocol, the majority of parameters were stable within 24 h, a condition that may not hold for the samples of patients with rare anemias. This implies for as short as possible shipping using fast courier services to the closest expert laboratory at reach. Mobile laboratories or the travel of the

  5. Effect of Irradiation on Microparticles in Red Blood Cell Concentrates.

    PubMed

    Cho, Chi Hyun; Yun, Seung Gyu; Koh, Young Eun; Lim, Chae Seung

    2016-07-01

    Changes in microparticles (MP) from red blood cell (RBC) concentrates in the context of irradiation have not been investigated. The aim of this study was to evaluate how irradiation affects the number of MPs within transfusion components. Twenty RBC concentrates, within 14 days after donation, were exposed to gamma rays (dose rate: 25 cGy) from a cesium-137 irradiator. Flow cytometry was used to determine the numbers of MPs derived from RBC concentrates before and 24 hr after irradiation. The mean number of MPs (±standard deviation) in RBC concentrates was 21.9×10⁹/L (±22.7×10⁹/L), and the total number of MPs ranged from 2.6×10⁹/L to 96.9×10⁹/L. The mean number of MPs increased to 22.6×10⁹/L (±31.6×10⁹/L) after irradiation. Before irradiation, the CD41-positive and CD235a-positive MPs constituted 9.5% (1.0×10⁹/L) and 2.2% (263×10⁶/L) of total MPs, respectively. After irradiation, CD41-positive MPs increased to 12.1% (1.5×10⁹/L) (P=0.014), but the CD235a-positive MPs decreased to 2.0% (214×10⁶/L) of the total MPs (P=0.369). Irradiation increases the number of CD41-positive MPs within RBC concentrates, suggesting the irradiation of RBC concentrates could be associated with thrombotic risk of circulating blood through the numerical change. PMID:27139610

  6. Red blood cell sodium transport in patients with cirrhosis.

    PubMed

    Henriksen, Ulrik Lütken; Kiszka-Kanowitz, Marianne; Bendtsen, Flemming; Henriksen, Jens H

    2016-09-01

    Patients with advanced cirrhosis have abnormal sodium homoeostasis. The study was undertaken to quantify the sodium transport across the plasma membrane of red blood cells (RBC) in patients with cirrhosis. RBC efflux and influx of sodium were studied in vitro with tracer (22) Na(+) according to linear kinetics in 24 patients with cirrhosis and 14 healthy controls. The sodium efflux was modified by ouabain (O), furosemide (F) and a combination of O and F (O + F). RBC sodium was significantly decreased (4·6 versus control 6·3 mmol l(-1) , P<0·001) and directly related to serum sodium (r = 0·57, P<0·05). The RBC fractional sodium efflux was higher in patients with cirrhosis (+46%, P<0·01) compared to controls. Inhibition in both high (145 mmol l(-1) )- and low (120 mmol l(-1) )-sodium buffers showed that the F-insensitive sodium efflux was twice as high in cirrhosis as in controls (P = 0·03-0·007), especially the O-sensitive, F-insensitive efflux was increased (+ 225%, P = 0·01-0·006). Fractional F-sensitive transport was normal in cirrhosis. RBC sodium influx was largely normal in cirrhosis. In conclusion, RBC sodium content is reduced in patients with cirrhosis with a direct relation to serum sodium. Increased RBC sodium efflux is especially related to ouabain-sensitive, furosemide-insensitive transport and thus most likely due to upregulated activity of the sodium-potassium pump. The study gives no evidence to an altered intracellular/extracellular sodium ratio or to a reduced fractional furosemide-sensitive sodium transport in cirrhosis. PMID:26016736

  7. Effect of Irradiation on Microparticles in Red Blood Cell Concentrates

    PubMed Central

    Cho, Chi Hyun; Yun, Seung Gyu; Koh, Young Eun

    2016-01-01

    Changes in microparticles (MP) from red blood cell (RBC) concentrates in the context of irradiation have not been investigated. The aim of this study was to evaluate how irradiation affects the number of MPs within transfusion components. Twenty RBC concentrates, within 14 days after donation, were exposed to gamma rays (dose rate: 25 cGy) from a cesium-137 irradiator. Flow cytometry was used to determine the numbers of MPs derived from RBC concentrates before and 24 hr after irradiation. The mean number of MPs (±standard deviation) in RBC concentrates was 21.9×109/L (±22.7×109/L), and the total number of MPs ranged from 2.6×109/L to 96.9×109/L. The mean number of MPs increased to 22.6×109/L (±31.6×109/L) after irradiation. Before irradiation, the CD41-positive and CD235a-positive MPs constituted 9.5% (1.0×109/L) and 2.2% (263×106/L) of total MPs, respectively. After irradiation, CD41-positive MPs increased to 12.1% (1.5×109/L) (P=0.014), but the CD235a-positive MPs decreased to 2.0% (214×106/L) of the total MPs (P=0.369). Irradiation increases the number of CD41-positive MPs within RBC concentrates, suggesting the irradiation of RBC concentrates could be associated with thrombotic risk of circulating blood through the numerical change. PMID:27139610

  8. Effects of pegylated hamster red blood cells on microcirculation.

    PubMed

    Chen, Peter C Y; Huang, Wei; Stassinopoulos, Adonis; Cheung, Anthony T W

    2008-01-01

    The objective of this study was to examine the effects of polyethylene glycol (PEG) treated red blood cells (RBCs) on the microcirculation in a hamster back skin window chamber model. Donor hamster RBCs were PEGylated through an incubation with an activated PEG solution, washed, resuspended, and infused through a 10% volume top loading procedure into the carotid artery in an awake Syrian Golden hamster. Eight hamster groups were treated with activated PEG different sizes and concentrations: 0.05 mM-5 kDa PEG, 0.5 mM-5 kDa PEG, 1.1 mM-5 kDa PEG, 2.2 mM-5 kDa PEG, 22 mM-5 kDa PEG, 0.05 mM-20 kDa PEG, 0.5 mM-20 kDa PEG, and 5 mM-20 kDa PEG. Non-treated RBCs were used as control. The microvascular bed under observation was videotaped 30 min before the infusion and followed for 30 min post infusion. The diameter of individual blood vessels and blood flow velocities in selected vessels was measured. Hematocrit and hemoglobin concentration were recorded before infusion and at the end of experiment. Tissue pO(2) was also monitored. Results showed the hamsters tolerated the PEGylated RBCs without apparent ill effects. No significant changes were recorded for the hematocrit, the hemoglobin concentration, the blood vessel diameters, blood flow velocities, and the interstitial partial oxygen pressure (pO(2)) before, during, and after the injections of PEG-RBCs (P > 0.05). Unlike most hemoglobin-based oxygen carrying compounds, which can cause vasoconstriction, the PEGylated RBCs did not produce any measurable vasoactivity. Together with the absence of rouleaux formation and the fact that PEG molecules can mask the surface antigens on RBCs, PEGylation appeared promising as a circulation enhancement treatment. PMID:18649167

  9. The fate of phenylhydroxylamine in human red cells.

    PubMed

    Kiese, M; Taeger, K

    1976-01-01

    Phenylhydroxylamine added to human red cells under aerobic conditions and in the presence of glucose was partly reduced to aniline. About half the hydroxylamine was recovered as amine after a 2-hr incubation. The aniline, after acetylation, was identified as acetanilide by melting point, Rf-value in TCL as well as UV, IR, and NMR spectroscopy. The fate of the remaining phenylhydroxylamine was followed by use of 14C-labeled phenylhydroxylamine. About 30% of the total radioactivity was bound to hemoglobin or other proteins and about 20% was found in highly polar low-molecular substances which were insoluble in organic solvents. The elucidation of the sites at which phenylhydroxylamine was bound to hemoglobin was complicated by the lability of the bonds. When purified human hemoglobin had reacted with radioactive phenylhydroxylamine, large proportions of the radioactivity bound to hemoglobin were removed by treatment with acid or with PMB for separation of alpha- and beta-chains. The radioactive compound liberated from hemoglobin by acid was found to be aniline. After reaction with phenylhydroxylamine the number of SH groups titrable with PMB was found to be diminished. Pretreatment of hemoglobin with N-ethylmaleimide or PMB decreased the amount of phenylhydroxylamine bound to hemoglobin but did not fully prevent the reaction. Tryptic digestion of hemoglobin after reaction with radioactive phenylhydroxylamine yielded tryptic peptides with lower specific activity than that of hemoglobin. Chymotryptic digestion of the tryptic core yielded a core with specific activity much higher than that of hemoglobin. Fingerprinting of the tryptic or chymotryptic hydrolyzates showed the presence of peptides with high and other ones with low or no radioactivity and of radioactive compounds which did not react with ninhydrin. In the covalent binding of phenylhydroxylamine to globin the SH group beta93 plays an important role, but other yet unknown sites are also reactive. PMID:934354

  10. Increased phorbol 12,13-dibutyrate (PDBu) receptor function associated with sickle red cell membrane ghosts

    SciTech Connect

    Ramachandran, M.; Nair, C.N.; Abraham, E.C.

    1987-05-01

    The biological receptor for tumor-promoting phorbol esters has been identified as the CaS /phospholipid dependent enzyme, protein kinase C. In the red cell, this enzyme is mainly cytosolic but becomes translocated to the membrane if the cellular CaS is allowed to rise. Since cellular CaS in sickle red cells is high, it was reasoned that this enzyme may become more membrane-bound. In fact, the authors noticed a four-fold increase in the binding of TH-PDBu by membrane ghosts isolated from sickle red cells compared to normal red cells (pmoles PDBu bound/mg protein; normal = 0.3 vs sickle cell = 1.4). Attempts to assay the enzyme directly as phospholipid-activated TSP incorporation into the acid-precipitable membrane proteins also indicated a two-fold increase in the radiolabelling of sickle cell membrane ghosts. Autophosphorylation of membrane proteins and analysis of the phosphorylation profile by SDS-PAGE and autoradiography revealed phosphorylation predominantly of bands 3, 4.1 and 4.9 which are known protein kinase C substrates for the red cell enzyme. The increased membrane-associated protein kinase C in sickle red cells may have a bearing on the altered membrane properties reported in this condition.

  11. Flow structures and red blood cell dynamics in arteriole of dilated or constricted cross section.

    PubMed

    Gambaruto, Alberto M

    2016-07-26

    Vessel with 'circular' or 'star-shaped' cross sections are studied, representing respectively dilated or constricted cases where endothelial cells smoothly line or bulge into the lumen. Computational haemodynamics simulations are carried out on idealised periodic arteriole-sized vessels, with red blood cell 'tube' hematocrit value=24%. A further simulation of a single red blood cell serves for comparison purposes. The bulk motion of the red blood cells reproduces well-known effects, including the presence of a cell-free layer and the apparent shear-thinning non-Newtonian rheology. The velocity flow field is analysed in a Lagrangian reference frame, relative to any given red blood cell, hence removing the bulk coaxial motion and highlighting instead the complex secondary flow patterns. An aggregate formation becomes apparent, continuously rearranging and dynamic, brought about by the inter-cellular fluid mechanics interactions and the deformability properties of the cells. The secondary flow field induces a vacillating radial migration of the red blood cells. At different radial locations, the red blood cells express different residence times, orientation and shape. The shear stresses exerted by the flow on the vessel wall are influenced by the motion of red blood cells, despite the presence of the cell-free layer. Spatial (and temporal) variations of wall shear stress patters are observed, especially for the 'circular' vessel. The 'star-shaped' vessel bears considerable stress at the protruding endothelial cell crests, where the stress vectors are coaxially aligned. The bulging endothelial cells hence regularise the transmission of stresses on the vessel wall. PMID:26822224

  12. Discrimination and classification of acute lymphoblastic leukemia cells by Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Managò, Stefano; Valente, Carmen; Mirabelli, Peppino; De Luca, Anna Chiara

    2015-05-01

    Currently, a combination of technologies is typically required to identify and classify leukemia cells. These methods often lack the specificity and sensitivity necessary for early and accurate diagnosis. Here, we demonstrate the use of Raman spectroscopy to identify normal B cells, collected from healthy patients, and three ALL cell lines (RS4;11, REH and MN60 at different differentiation level, respectively). Raman markers associated with DNA and protein vibrational modes have been identified that exhibit excellent discriminating power for leukemia cell identification. Principal Component Analysis was finally used to confirm the significance of these markers for identify leukemia cells and classifying the data. The obtained results indicate a sorting accuracy of 96% between the three leukemia cell lines.

  13. Red light interferes in UVA-induced photoaging of human skin fibroblast cells.

    PubMed

    Niu, Tianhui; Tian, Yan; Ren, Qu; Wei, Lizhao; Li, Xiaoxin; Cai, Qing

    2014-01-01

    The possible regulation mechanism of red light was determined to discover how to retard UVA-induced skin photoaging. Human skin fibroblasts were cultured and irradiated with different doses of UVA, thus creating a photoaging model. Fibroblasts were also exposed to a subtoxic dose of UVA combined with a red light-emitting diode (LED) for five continuous days. Three groups were examined: control, UVA and UVA plus red light. Cumulative exposure doses of UVA were 25 J cm(-2), and the total doses of red light were 0.18 J cm(-2). Various indicators were measured before and after irradiation, including cell morphology, viability, β-galactosidase staining, apoptosis, cycle phase, the length of telomeres and the protein levels of photoaging-related genes. Red light irradiation retarded the cumulative low-dose UVA irradiation-induced skin photoaging, decreased the expression of senescence-associated β-galactosidase, upregulated SIRT1 expression, decreased matrix metalloproteinase MMP-1 and the acetylation of p53 expression, reduced the horizon of cell apoptosis and enhanced cell viability. Furthermore, the telomeres in UVA-treated cells were shortened compared to those of cells in the red light groups. These results suggest that red light plays a key role in the antiphotoaging of human skin fibroblasts by acting on different signaling transduction pathways. PMID:25039464

  14. Biosignatures of Kerala red rain cells: Implications in understanding their origin

    NASA Astrophysics Data System (ADS)

    Gangappa, R.; Thomas, M.; Hogg, S.

    2013-09-01

    The red rain that fell over Kerala, southern India (2001-2012) was characterised by the red pigmented particles. Earlier proposal claiming that these are known algal bloom blown from trees (Sampath et al, 2001; DiGregorio, 2007) has been studied by us and disproved. Also, further investigation reporting their extraordinary properties including a suggestion that they lack DNA (Louis and Kumar 2003; 2006; 2008) has been invalidated (Gangappa and Hogg, 2013). However, their claim regarding the growth and replication of these cells at 300ºC needs more investigation if it is to gain acceptance. Current study provide evidences regarding the biological properties of Kerala red rain cells to gain insights into environmental conditions from which they may have originated. Combined with various research strategies and high resolution instruments, we have demonstrated the following interesting properties of Kerala red rain cells: (1) unusually thick external envelope enclosing the central core; (2)stability of red pigment at temperatures about 100ºC and pH variations; (3) absence of eukaryotic ultrastructures; (4) possible replication at 121ºC with nanostructures (possible daughter cells) having similar morphological features inside the large mother cells at such high temperature. They contain high percentage of carbon, iron, silicon and aluminum and often enclosed in a silicon rich biofilms. Further investigation shows that the positive detection of DNA in these cells was possible only after the complete removal of red pigment, thereby providing an explanation for the negative outcome of earlier studies in this regard. Moreover, evidences are shown to support that these cells contain high amounts of UV absorbing compounds, porphyrin complexes and possible scytonemin. Kerala red rain cells may prove to be polyextermophiles belonging to prokaryotes and may have possibly originated from the environment containing above mentioned chemical elements, high energy UV exposure and

  15. Studies with nonradioisotopic sodium chromate. I. Development of a technique for measuring red cell volume

    SciTech Connect

    Heaton, W.A.; Hanbury, C.M.; Keegan, T.E.; Pleban, P.; Holme, S. )

    1989-10-01

    A nonradioisotopic method for measuring red cell volume that involves the use of 52Cr-sodium chromate as the red cell label and of graphite furnace atomic absorption analysis of chromium is described. The technique allows the labelling of 20 mL of packed red cells with 40 to 50 micrograms of sodium chromate (Na2CrO4) in 30 minutes at 22 degrees C with 94 +/- 6 percent uptake. Approximately 40 micrograms of Na2CrO4 was injected for in vivo studies. This results in posttransfusion in vivo red cell chromium levels after sample processing in the range of 1 to 7 micrograms per L, which could be quantitated accurately (coefficient of variation = 4.7%) by Zeeman electrothermal atomic absorption spectrophotometry. The labeling concentration of chromium did not cause increased hemolysis, and the labeled cells exhibited an osmotic fragility curve similar to that of unlabeled, fresh ACD red cells. Red cell glutathione peroxidase was unaffected by labeling, although glutathione reductase was reduced by approximately 13 percent (p less than 0.05). The 52Cr red cell volume-measuring method was evaluated by concurrent in vivo studies with the standard 51Cr and 125I-albumin methods for that procedure. Simultaneous measurement of red cell volumes in seven volunteers by the 51Cr, 52Cr, and 125I-albumin techniques correlated highly with each other (r greater than 0.76), with mean values of 2294 +/- 199, 2191 +/- 180, and 2243 +/- 291 mL, respectively. The standard deviations of the differences were small: 134 mL for 52Cr versus 51Cr and 183 mL for 52Cr versus 125I.

  16. Method for extending the useful shelf-life of refrigerated red blood cells by flushing with inert gas

    DOEpatents

    Bitensky, M.W.; Yoshida, Tatsuro

    1997-04-29

    A method is disclosed using oxygen removal for extending the useful shelf-life of refrigerated red blood cells. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. Preservation of adenosine triphosphate levels and reduction in hemolysis and in membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time is achieved by removing oxygen from the red blood cells at the time of storage; in particular, by flushing with an inert gas. Adenosine triphosphate levels of the stored red blood cells are boosted in some samples by addition of ammonium phosphate. 4 figs.

  17. Current issues relating to the transfusion of stored red blood cells.

    PubMed

    Zimrin, A B; Hess, J R

    2009-02-01

    The development of blood storage systems allowed donation and transfusion to be separated in time and space. This separation has permitted the regionalization of donor services with subsequent economies of scale and improvements in the quality and availability of blood products. However, the availability of storage raises the question of how long blood products can and should be stored and how long they are safe and effective. The efficacy of red blood cells was originally measured as the increment in haematocrit and safety began with typing and the effort to reduce the risk of bacterial contamination. Appreciation of a growing list of storage lesions of red blood cells has developed with our increasing understanding of red blood cell physiology and our experience with red blood cell transfusion. However, other than frank haemolysis, rare episodes of bacterial contamination and overgrowth, the reduction of oxygen-carrying capacity associated with the failure of some transfused cells to circulate, and the toxicity of lysophospholipids released from membrane breakdown, storage-induced lesions have not had obvious correlations with safety or efficacy. The safety of red blood cell storage has also been approached in retrospective epidemiologic studies of transfused patients, but the results are frequently biased by the fact that sicker patients are transfused more often and blood banks do not issue blood products in a random order. Several large prospective studies of the safety of stored red blood cells are planned. PMID:19152602

  18. Effects of 4000 rad irradiation on the in vitro storage properties of packed red cells

    SciTech Connect

    Moore, G.L.; Ledford, M.E.

    1985-11-01

    Immunosuppressed patients who require red cell transfusions receive irradiated (1500-3000 rad) packed red cells. These cells are irradiated immediately before infusion. If a large group of patients become immunosuppressed due to exposure to radiation or chemicals, the ability to supply large volumes of irradiated blood at the time of use might not be possible. An alternate solution to providing quantities of irradiated blood is to irradiate the units prior to storage. This study presents in vitro data comparing storage of paired packed red cell units either irradiated or not irradiated. Five units of fresh blood drawn into citrate-phosphate-dextrose-adenine (CPDA-1) were packed to a hematocrit of 75 +/- 1 percent, and then each unit was divided in two equal parts. One of each pair was irradiated (4000 rads), and both parts of each unit were stored for 35 days at 4 degrees C. Samples were analyzed every 7 days. Irradiation caused a slight drop in red cell adenosine triphosphate and 2,3 diphosphoglycerate and a slight increase in plasma hemoglobin compared to controls. Methemoglobin, pH, and glucose consumption were identical to the controls. The evidence indicates that irradiation did not cause biochemical or metabolic changes in the red cells that would lead us to suspect a difference between irradiated and nonirradiated stored red cells in function or viability. These negative findings require in vivo confirmation.

  19. Fetal anaemia from red blood cell membrane defect and co-inherited haemoglobin Constant Spring.

    PubMed

    Srisupundit, Kasemsri; Charoenkwan, Pimlak; Traisrisilp, Kuntharee; Tongsong, Theera

    2015-01-01

    The case presented here is an example of hereditary red blood cell membrane defect with a co-inherited haemoglobin Constant Spring. This case is of an anaemic fetus that presented with isolated ascites at 18 weeks of gestation. Fetal blood analysis revealed abnormal shaped red blood cells. The same pattern of red blood cell morphology was also seen on paternal peripheral blood smear. Intrauterine blood transfusions were given twice to correct fetal anaemia. The fetus showed a good response to the transfusions and was delivered at term with mild anaemia and did not need blood transfusion after birth. This report describes a natural course of red blood cell membrane defect with co-inherited haemoglobin Constant Spring, indicating that the course of disease was more severe during fetal life. Intrauterine transfusion supported the transition of the fetus through the critical period in utero to a healthier life after birth. PMID:26216922

  20. Photoacoustic assessment of oxygen saturation: effect of red blood cell aggregation

    NASA Astrophysics Data System (ADS)

    Hysi, Eno; Saha, Ratan K.; Kolios, Michael C.

    2013-03-01

    The simultaneous photoacoustic assessment of oxygen saturation and red blood cell aggregation is presented. Aggregation was induced on porcine red blood cells using Dextran-70 at multiple hematocrit levels. Samples were exposed to 750 nm and 1064 nm for each hematocrit and aggregate size in order to compute the oxygen saturation. As the size of the aggregate increased, the photoacoustic signal amplitude increased monotonically. The same trend was observed for increasing hematocrit at each aggregation level. The oxygen saturation of aggregated samples was 30% higher than non-aggregated samples at each hematocrit level. This suggests that the presence of red blood cell aggregates impairs the release of oxygen to the surrounding environment. Such a result has important implications for detecting red blood cell aggregation non-invasively and making clinical decisions based on the simulatenous assessment of oxygen saturation.

  1. History-Dependent Excitability as a Single-Cell Substrate of Transient Memory for Information Discrimination

    PubMed Central

    Baroni, Fabiano; Torres, Joaquín J.; Varona, Pablo

    2010-01-01

    Neurons react differently to incoming stimuli depending upon their previous history of stimulation. This property can be considered as a single-cell substrate for transient memory, or context-dependent information processing: depending upon the current context that the neuron “sees” through the subset of the network impinging on it in the immediate past, the same synaptic event can evoke a postsynaptic spike or just a subthreshold depolarization. We propose a formal definition of History-Dependent Excitability (HDE) as a measure of the propensity to firing in any moment in time, linking the subthreshold history-dependent dynamics with spike generation. This definition allows the quantitative assessment of the intrinsic memory for different single-neuron dynamics and input statistics. We illustrate the concept of HDE by considering two general dynamical mechanisms: the passive behavior of an Integrate and Fire (IF) neuron, and the inductive behavior of a Generalized Integrate and Fire (GIF) neuron with subthreshold damped oscillations. This framework allows us to characterize the sensitivity of different model neurons to the detailed temporal structure of incoming stimuli. While a neuron with intrinsic oscillations discriminates equally well between input trains with the same or different frequency, a passive neuron discriminates better between inputs with different frequencies. This suggests that passive neurons are better suited to rate-based computation, while neurons with subthreshold oscillations are advantageous in a temporal coding scheme. We also address the influence of intrinsic properties in single-cell processing as a function of input statistics, and show that intrinsic oscillations enhance discrimination sensitivity at high input rates. Finally, we discuss how the recognition of these cell-specific discrimination properties might further our understanding of neuronal network computations and their relationships to the distribution and functional

  2. Novel insights into red blood cell physiology using parasites as tools.

    PubMed

    Baumeister, Stefan; Gangopadhyay, Preetish; Repnik, Urska; Lingelbach, Klaus

    2015-01-01

    The mammalian red blood cell is a terminally differentiated cell that lacks a genetic programme and that has only a very limited metabolic capacity. Nonetheless, it serves as habitat for two parasites belonging to the monophyletic group of Apicomplexa, namely Plasmodium and Babesia. Studies of the parasitized red blood cell have revealed several properties that are unknown in the non-infected cell and that are difficult to conceptualize based on our view of red blood cell function. Here we review the current knowledge on host cell invasion and nutrient acquisition by these parasites. We attempt to dissect the factors that are directly contributed by the parasites from those that exist but have remained undetected in the non-infected cell. PMID:26105829

  3. Biotransformation of nitrosobenzene in the red cell and the role of glutathione.

    PubMed

    Eyer, P; Lierheimer, E

    1980-01-01

    1. In the red cell nitrosobenzene formed glutathione-sulphinanilide from reduced glutathione, and the corresponding sulphinanilide with the reactive cysteine residues of haemoglobin. 2. Glutathionesulphinanilide was reductively cleaved by an NADPH-linked reductase with formation of free analine half an equivalent of reduced glutathione and half of glutathione sulphinic acid. 3. About three quarters of the aniline produced from nitrosobenzene or phenylhydroxylamine was formed via this pathway within the red cell. PMID:6893778

  4. Pure red cell aplasia in a simultaneous pancreas-kidney transplantation patient: inside the erythroblast

    PubMed Central

    Labbadia, Francesca; Salido-Fierréz, Eduardo; Majado-Martinez, Juliana; Cabañas-Perianes, Valentin; Moraleda, Jiménez José M.

    2012-01-01

    A case of pure red cell aplasia in a simultaneous kidney-pancreas transplant recipient on immunosuppressive therapy is reported here. The patient presented with anemia unresponsive to erythropoietin treatment. Bone marrow cytomorphology was highly suggestive of parvovirus pure red cell aplasia, which was confirmed with serology and polymerase chain reaction positive for parvovirus B19 DNA in peripheral blood. After the administration of intravenous immunoglobulin the anemia improved with a rising number of the reticulocytes. PMID:23087806

  5. Mechanical property analysis of stored red blood cell using optical tweezers.

    PubMed

    Li, Yanjie; Wen, Cheng; Xie, Huimin; Ye, Anpei; Yin, Yajun

    2009-05-01

    The deformation of human red blood cells subjected to direct stretching by optical tweezers was analyzed. The maximum force exerted by optical tweezers on the cell via a polystyrene microbead 5microm in diameter was 315pN. Digital image correlation (DIC) method was introduced to calculate the force and the deformation of the cell for the first time. Force-extension relation curves of the biconcave cell were quantitatively assessed when erythrocytes were stored in Alsever's Solution for 2 days, 5 days, 7 days and 14 days respectively. Experiment results demonstrated that the deformability of red blood cells was impaired with the stored time. PMID:19168336

  6. Mechanical and electrical properties of red blood cells using optical tweezers

    NASA Astrophysics Data System (ADS)

    Fontes, A.; Barjas Castro, M. L.; Brandão, M. M.; Fernandes, H. P.; Thomaz, A. A.; Huruta, R. R.; Pozzo, L. Y.; Barbosa, L. C.; Costa, F. F.; Saad, S. T. O.; Cesar, C. L.

    2011-04-01

    Optical tweezers are a very sensitive tool, based on photon momentum transfer, for individual, cell by cell, manipulation and measurements, which can be applied to obtain important properties of erythrocytes for clinical and research purposes. Mechanical and electrical properties of erythrocytes are critical parameters for stored cells in transfusion centers, immunohematological tests performed in transfusional routines and in blood diseases. In this work, we showed methods, based on optical tweezers, to study red blood cells and applied them to measure apparent overall elasticity, apparent membrane viscosity, zeta potential, thickness of the double layer of electrical charges and adhesion in red blood cells.

  7. Improved stop-flow apparatus to measure permeability of human red cells and ghosts.

    PubMed

    Levin, S W; Levin, R L; Solomon, A K; Pandiscio, A; Kirkwood, D H

    1980-11-01

    An improved stop-flow apparatus has been designed and constructed to measure the permeability characteristics of human red cells, which can be inferred from the time course of red cell volume changes following a sudden change in cellular environment produced by a raped mixing device. The improved apparatus is directly coupled to a computer which automates the subtraction and averaging procedures that have been developed to minimize the noise generated in the system by the cessation of red cell forward motion when the flow is suddenly stopped. Real time data acquisition also makes it possible to increase the number of data points by an order of magnitude, thus improving accuracy significantly. The apparatus has been tested by measurements of the human red cell hydraulic permeability coefficient. Data are presented to validate the subtraction procedure. Experiments have also been carried out on red cell ghosts which indicate that the hydraulic conductivity of the ghost is similar to that of the undisturbed red cell. PMID:7002984

  8. Red Blood Cell Hematocrit Influences Platelet Adhesion Rate in a Microchannel

    NASA Astrophysics Data System (ADS)

    Spann, Andrew; Campbell, James; Fitzgibbon, Sean; Rodriguez, Armando; Shaqfeh, Eric

    2014-11-01

    The creation of a blood clot to stop bleeding involves platelets forming a plug at the site of injury. Red blood cells indirectly play a role in ensuring that the distribution of platelets across the height of the channel is not uniform - the contrast in deformability and size between platelets and red blood cells allows the platelets to preferentially marginate close to the walls. We perform 3D boundary integral simulations of a suspension of platelets and red blood cells in a periodic channel with a model that allows for platelet binding at the walls. The relative rate of platelet activity with varying hematocrit (volume fraction of red blood cells) is compared to experiments in which red blood cells and platelets flow through a channel coated with von Willebrand factor. In the simulations as well as the experiments, a decrease in hematocrit of red blood cells is found to reduce the rate at which platelets adhere to the channel wall in a manner that is both qualitatively and quantitatively similar. We conclude with a discussion of the tumbling and wobbling motions of platelets in 3D leading up to the time at which the platelets bind to the wall. Funded by Stanford Army High Performance Computing Research Center, experiments by US Army Institute of Surgical Research.

  9. Light collection and pulse-shape discrimination in elongated scintillator cells for the PROSPECT reactor antineutrino experiment

    NASA Astrophysics Data System (ADS)

    Ashenfelter, J.; Balantekin, B.; Band, H. R.; Barclay, G.; Bass, C. D.; Berish, D.; Bowden, N. S.; Bowes, A.; Brodsky, J. P.; Bryan, C. D.; Cherwinka, J. J.; Chu, R.; Classen, T.; Commeford, K.; Davee, D.; Dean, D.; Deichert, G.; Diwan, M. V.; Dolinski, M. J.; Dolph, J.; Dwyer, D. A.; Gaison, J. K.; Galindo-Uribarri, A.; Gilje, K.; Glenn, A.; Goddard, B. W.; Green, M.; Han, K.; Hans, S.; Heeger, K. M.; Heffron, B.; Jaffe, D. E.; Langford, T. J.; Littlejohn, B. R.; Martinez Caicedo, D. A.; McKeown, R. D.; Mendenhall, M. P.; Mueller, P.; Mumm, H. P.; Napolitano, J.; Neilson, R.; Norcini, D.; Pushin, D.; Qian, X.; Romero, E.; Rosero, R.; Saldana, L.; Seilhan, B. S.; Sharma, R.; Sheets, S.; Stemen, N. T.; Surukuchi, P. T.; Varner, R. L.; Viren, B.; Wang, W.; White, B.; White, C.; Wilhelmi, J.; Williams, C.; Wise, T.; Yao, H.; Yeh, M.; Yen, Y. R.; Zangakis, G.; Zhang, C.; Zhang, X.

    2015-11-01

    A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron-gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. Key design features for optimizing MeV-scale response and background rejection capabilities are identified.

  10. Light collection and pulse-shape discrimination in elongated scintillator cells for the PROSPECT reactor antineutrino experiment

    SciTech Connect

    Ashenfelter, J.; Jaffe, D.; Diwan, M. V.; Dolph, J.; Qian, X.; Sharma, R.; Viren, B.; Zhang, C.

    2015-11-06

    A meter-long, 23-liter EJ-309 liquid scintillator detector has been constructed to study the light collection and pulse-shape discrimination performance of elongated scintillator cells for the PROSPECT reactor antineutrino experiment. The magnitude and uniformity of light collection and neutron-gamma discrimination power in the energy range of antineutrino inverse beta decay products have been studied using gamma and spontaneous fission calibration sources deployed along the cell axis. We also study neutron-gamma discrimination and light collection abilities for differing PMT and reflector configurations. As a result, key design features for optimizing MeV-scale response and background rejection capabilities are identified.

  11. An Improved Method for High-throughput Discrimination and Enumeration of Sedimentary Cells Using Flow Cytometry

    NASA Astrophysics Data System (ADS)

    Morono, Y.; Kallmeyer, J.; Terada, T.; Inagaki, F.; IODP Expedition 329 Shipboard Science Party

    2011-12-01

    Detection and enumeration of microbial life in marine subsurface environments provides primary information on the extent and habitability of the Earth's biosphere. Flow cytometry (FCM) is a powerful tool for identifying and enumerating fluorescence-stained cells with high throughput, using fluorescent intensity, range of wavelength, and cell size. FCM is widely used in medical sciences and aquatic microbial ecology. However, mineral grains and difficulties in distinguishing between life cells and non-specific background fluorescence prevented FCM to be applied for counting microbial cells in sediment or rock samples. SYBR Green I-stained cells can be distinguished from non-biological background signals based on differences in their fluorescence spectra. Here we extended this technique to FCM analysis by modifying the cell detachment protocol using a density gradient method, and then standardized an FCM cell counting method for various types of marine subsurface sediments. Microbial cells in sediment samples could effectively be detached and analyzed discriminatively with FCM. The high capacity of FCM to count particles (up to 10,000 cells/sec) and its high sensitivity will provide information about microbial cell abundance at high spatial resolution and with unprecedented accuracy. This improved cell count method will be useful to evaluate samples with high depth resolution, including narrow geochemical and geological interfaces as potential specific microbial niches, and may even help to asses very low population densities at the fringe of the biosphere.

  12. Discrimination of Human Cell Lines by Infrared Spectroscopy and Mathematical Modeling.

    PubMed

    Zendehdel, Rezvan; H Shirazi, Farshad

    2015-01-01

    Variations in biochemical features are extensive among cells. Identification of marker that is specific for each cell is essential for following the differentiation of stem cell and metastatic growing. Fourier transform infrared spectroscopy (FTIR) as a biochemical analysis more focused on diagnosis of cancerous cells. In this study, commercially obtained cell lines such as Human ovarian carcinoma (A2780), Human lung adenocarcinoma (A549) and Human hepatocarcinoma (HepG2) cell lines in 20 individual samples for each cell lines were used for FTIR spectral measurements. Data dimension were reduced through principal component analysis (PCA) and then subjected to neural network and linear discrimination analysis to classify FTIR pattern in different cell lines. The results showed dramatic changes of FTIR spectra among different cell types. These appeared to be associated with changes in lipid bands from CH2 symmetric and asymmetric bands, as well as amide I and amid II bands of proteins. The PCA-ANN analysis provided over 90% accuracy for classifying the spectrum of lipid section in different cell lines. This work supports future study to establish the data bank of FTIR feature for different cells and move forward to tissues as more complex systems. PMID:26330868

  13. Reflectance confocal microscopy of red blood cells: simulation and experiment (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zeidan, Adel; Yeheskely-Hayon, Daniella; Minai, Limor; Yelin, Dvir

    2016-03-01

    The properties of red blood cells are a remarkable indicator of the body's physiological condition; their density could indicate anemia or polycythemia, their absorption spectrum correlates with blood oxygenation, and their morphology is highly sensitive to various pathologic states including iron deficiency, ovalocytosis, and sickle cell disease. Therefore, measuring the morphology of red blood cells is important for clinical diagnosis, providing valuable indications on a patient's health. In this work, we simulated the appearance of normal red blood cells under a reflectance confocal microscope and discovered unique relations between the cells' morphological parameters and the resulting characteristic interference patterns. The simulation results showed good agreement with in vitro reflectance confocal images of red blood cells, acquired using spectrally encoded flow cytometry (SEFC) that imaged the cells during linear flow and without artificial staining. By matching the simulated patterns to the SEFC images of the cells, the cells' three-dimensional shapes were evaluated and their volumes were calculated. Potential applications include measurement of the mean corpuscular volume, cell morphological abnormalities, cell stiffness under mechanical stimuli, and the detection of various hematological diseases.

  14. Small-angle X-ray scattering probe of intermolecular interaction in red blood cells

    NASA Astrophysics Data System (ADS)

    Liu, Guan-Fen; Wang, We-Jia; Xu, Jia-Hua; Dong, Yu-Hui

    2015-03-01

    With high concentrations of hemoglobin (Hb) in red blood cells, self-interactions among these molecules could increase the propensities of their polymerization and aggregation. In the present work, high concentration Hb in solution and red blood cells were analyzed by small-angle X-ray scattering. Calculation of the effective structure factor indicates that the interaction of Hb molecules is the same when they are crowded together in both the cell and physiological saline. The Hb molecules stay individual without the formation of aggregates and clusters in cells. Supported by National Basic Research Program of China (2009CB918600) and National Natural Science Foundation of China (10979005)

  15. Force Balance and Membrane Shedding at the Red-Blood-Cell Surface

    NASA Astrophysics Data System (ADS)

    Sens, Pierre; Gov, Nir

    2007-01-01

    During the aging of the red-blood cell, or under conditions of extreme echinocytosis, membrane is shed from the cell plasma membrane in the form of nanovesicles. We propose that this process is the result of the self-adaptation of the membrane surface area to the elastic stress imposed by the spectrin cytoskeleton, via the local buckling of membrane under increasing cytoskeleton stiffness. This model introduces the concept of force balance as a regulatory process at the cell membrane and quantitatively reproduces the rate of area loss in aging red-blood cells.

  16. Detection of Plasmodium falciparum-infected red blood cells by optical stretching

    NASA Astrophysics Data System (ADS)

    Mauritz, Jakob M. A.; Tiffert, Teresa; Seear, Rachel; Lautenschläger, Franziska; Esposito, Alessandro; Lew, Virgilio L.; Guck, Jochen; Kaminski, Clemens F.

    2010-05-01

    We present the application of a microfluidic optical cell stretcher to measure the elasticity of malaria-infected red blood cells. The measurements confirm an increase in host cell rigidity during the maturation of the parasite Plasmodium falciparum. The device combines the selectivity and sensitivity of single-cell elasticity measurements with a throughput that is higher than conventional single-cell techniques. The method has potential to detect early stages of infection with excellent sensitivity and high speed.

  17. On the agglutinogens of red cells developed with proteolytic enzymes and neuraminidase.

    PubMed

    Sagisaka, K; Takahashi, K

    1976-10-01

    It has been known that the agglutinability of human red cells is changed or enhanced by treatments with proteolytic enzymes or neuraminidase. In this paper, the serological properties of agglutinogens developed by proteolytic enzymes (bromelin, ficin, papain, trypsin and pronase) and neuraminidase are investigated by using antisera to trypsin- and neuraminidase-treated red cells. The adsorptions of the antiserum to trypsinized red cells with the cells treated with each of the proteolytic enzymes showed that the agglutinogens uncovered by bromelin, ficin and papain were different from those by pronase and trypsin. It was demonstrated that pronase was the most effective enzyme to uncover the agglutinogen located on deeper site of red cell membrane. This was confirmed by the agglutination with the test cells treated twice with two kinds of the enzymes. The reactions of the antiserum to neuraminidase-treated red cells treated with six kinds of the enzymes indicated that the agglutinogens developed by neuraminidase resembled those by bromelin, ficin and papain more than those by trypsin and pronase. PMID:982434

  18. In-vitro stem cell derived red blood cells for transfusion: are we there yet?

    PubMed

    Kim, Hyun Ok

    2014-03-01

    To date, the use of red blood cells (RBCs) produced from stem cells in vitro has not proved practical for routine transfusion. However, the perpetual and widespread shortage of blood products, problems related to transfusion-transmitted infections, and new emerging pathogens elicit an increasing demand for artificial blood. Worldwide efforts to achieve the goal of RBC production through stem cell research have received vast attention; however, problems with large-scale production and cost effectiveness have yet to prove practical usefulness. Some progress has been made, though, as cord blood stem cells and embryonic stem cells have shown an ability to differentiate and proliferate, and induced pluripotent stem cells have been shown to be an unlimited source for RBC production. However, transfusion of stem cell-derived RBCs still presents a number of challenges to overcome. This paper will summarize an up to date account of research and advances in stem cell-derived RBCs, delineate our laboratory protocol in producing RBCs from cord blood, and introduce the technological developments and limitations to current RBC production practices. PMID:24532496

  19. Dynamic quantitative photothermal monitoring of cell death of individual human red blood cells upon glucose depletion

    NASA Astrophysics Data System (ADS)

    Vasudevan, Srivathsan; Chen, George Chung Kit; Andika, Marta; Agarwal, Shuchi; Chen, Peng; Olivo, Malini

    2010-09-01

    Red blood cells (RBCs) have been found to undergo ``programmed cell death,'' or eryptosis, and understanding this process can provide more information about apoptosis of nucleated cells. Photothermal (PT) response, a label-free photothermal noninvasive technique, is proposed as a tool to monitor the cell death process of living human RBCs upon glucose depletion. Since the physiological status of the dying cells is highly sensitive to photothermal parameters (e.g., thermal diffusivity, absorption, etc.), we applied linear PT response to continuously monitor the death mechanism of RBC when depleted of glucose. The kinetics of the assay where the cell's PT response transforms from linear to nonlinear regime is reported. In addition, quantitative monitoring was performed by extracting the relevant photothermal parameters from the PT response. Twofold increases in thermal diffusivity and size reduction were found in the linear PT response during cell death. Our results reveal that photothermal parameters change earlier than phosphatidylserine externalization (used for fluorescent studies), allowing us to detect the initial stage of eryptosis in a quantitative manner. Hence, the proposed tool, in addition to detection of eryptosis earlier than fluorescence, could also reveal physiological status of the cells through quantitative photothermal parameter extraction.

  20. In-Vitro Stem Cell Derived Red Blood Cells for Transfusion: Are We There Yet?

    PubMed Central

    2014-01-01

    To date, the use of red blood cells (RBCs) produced from stem cells in vitro has not proved practical for routine transfusion. However, the perpetual and widespread shortage of blood products, problems related to transfusion-transmitted infections, and new emerging pathogens elicit an increasing demand for artificial blood. Worldwide efforts to achieve the goal of RBC production through stem cell research have received vast attention; however, problems with large-scale production and cost effectiveness have yet to prove practical usefulness. Some progress has been made, though, as cord blood stem cells and embryonic stem cells have shown an ability to differentiate and proliferate, and induced pluripotent stem cells have been shown to be an unlimited source for RBC production. However, transfusion of stem cell-derived RBCs still presents a number of challenges to overcome. This paper will summarize an up to date account of research and advances in stem cell-derived RBCs, delineate our laboratory protocol in producing RBCs from cord blood, and introduce the technological developments and limitations to current RBC production practices. PMID:24532496

  1. CARS hyperspectral imaging of cartilage aiming for state discrimination of cell

    NASA Astrophysics Data System (ADS)

    Shiozawa, Manabu; Shirai, Masataka; Izumisawa, Junko; Tanabe, Maiko; Watanabe, Koichi

    2016-03-01

    Non-invasive cell analyses are increasingly important for medical field. A CARS microscope is one of the non-invasive imaging equipments and enables to obtain images indicating molecular distribution. Some studies on discrimination of cell state by using CARS images of lipid are reported. However, due to low signal intensity, it is still challenging to obtain images of the fingerprint region (800~1800 cm-1), in which many spectrum peaks correspond to compositions of a cell. Here, to identify cell differentiation by using multiplex CARS, we investigated hyperspectral imaging of fingerprint region of living cells. To perform multiplex CARS, we used a prototype of a compact light source, which consists of a microchip laser, a single-mode fiber, and a photonic crystal fiber to generate supercontinuum light. Assuming application to regenerative medicine, we chose a cartilage cell, whose differentiation is difficult to be identified by change of the cell morphology. Because one of the major components of cartilage is collagen, we focused on distribution of proline, which accounts for approximately 20% of collagen in general. The spectrum quality was improved by optical adjustments about power branching ratio and divergence of broadband Stokes light. Hyperspectral images were successfully obtained by the improvement. Periphery of a cartilage cell was highlighted in CARS image of proline, and this result suggests correspondence with collagen generated as extracellular matrix. A possibility of cell analyses by using CARS hyperspectral imaging was indicated.

  2. Neocytolysis on descent from altitude: a newly recognized mechanism for the control of red cell mass

    NASA Technical Reports Server (NTRS)

    Rice, L.; Ruiz, W.; Driscoll, T.; Whitley, C. E.; Tapia, R.; Hachey, D. L.; Gonzales, G. F.; Alfrey, C. P.

    2001-01-01

    BACKGROUND: Studies of space-flight anemia have uncovered a physiologic process, neocytolysis, by which young red blood cells are selectively hemolyzed, allowing rapid adaptation when red cell mass is excessive for a new environment. OBJECTIVES: 1) To confirm that neocytolysis occurs in another situation of acute plethora-when high-altitude dwellers with polycythemia descend to sea level; and 2) to clarify the role of erythropoietin suppression. DESIGN: Prospective observational and interventional study. SETTING: Cerro de Pasco (4380 m) and Lima (sea level), Peru. PARTICIPANTS: Nine volunteers with polycythemia. INTERVENTIONS: Volunteers were transported to sea level; three received low-dose erythropoietin. MEASUREMENTS: Changes in red cell mass, hematocrit, hemoglobin concentration, reticulocyte count, ferritin level, serum erythropoietin, and enrichment of administered(13)C in heme. RESULTS: In six participants, red cell mass decreased by 7% to 10% within a few days of descent; this decrease was mirrored by a rapid increase in serum ferritin level. Reticulocyte production did not decrease, a finding that establishes a hemolytic mechanism.(13)C changes in circulating heme were consistent with hemolysis of young cells. Erythropoietin was suppressed, and administration of exogenous erythropoietin prevented the changes in red cell mass, serum ferritin level, and(13)C-heme. CONCLUSIONS: Neocytolysis and the role of erythropoietin are confirmed in persons with polycythemia who descend from high altitude. This may have implications that extend beyond space and altitude medicine to renal disease and other situations of erythropoietin suppression, hemolysis, and polycythemia.

  3. Red cell parameters in infant and children from the Arabian Peninsula

    PubMed Central

    Mekaini, Lolowa A Al; Denic, Srdjan; Jabri, Omar N Al; Narchi, Hassib; Souid, Abdul-Kader; Al-Hammadi, Suleiman

    2015-01-01

    α+-Thalassemia trait and iron deficiency anemia are frequent causes of microcytosis and a common diagnostic challenge in Arabian children. In this study, their prevalences and effects on the red cell parameters were evaluated in 28,457 children aged one day to 6 years. α+-Thalassemia trait was considered to be present when mean cell volume (MCV) was <94 fL at birth and iron deficiency anemia when red cell distribution width (RDW) was >14.5%. The prevalence of α+-thalassemia trait was 15.7% (502/3,191), which was similar to previously reported values for adults (9-14%). Iron deficiency anemia peaked at 7 months (53%) and then declined at a rate of 8% per year. The nadirs of red blood cell count (RBC) and hemoglobin concentration (Hb) occurred at two months of age (physiological anemia). Subsequently, Hb increased at a rate similar to that of MCV, demonstrating the two processes are coupled. The third percentile MCV in children older than 3 months was ≤64 fL, which was significantly lower than that in European children. The third percentile Hb, on the other hand, was similar to that in European children. Thus, α+-thalassemia trait and iron deficiency anemia are exceptionally frequent in Arabian children and their red cell indices are considerably different from European-based norms. Careful interpretation of red cell parameters is required for the evaluation of microcytic anemia in Arabian children. PMID:27069759

  4. Direct In Vivo Electrochemical Detection of Haemoglobin in Red Blood Cells

    NASA Astrophysics Data System (ADS)

    Toh, Rou Jun; Peng, Weng Kung; Han, Jongyoon; Pumera, Martin

    2014-08-01

    The electrochemical behavior of iron ion in haemoglobin provides insight to the chemical activity in the red blood cell which is important in the field of hematology. Herein, the detection of haemoglobin in human red blood cells on glassy carbon electrode (GC) was demonstrated. Red blood cells or raw blood cells was immobilized on a glassy carbon electrode surface with Nafion films employed to sandwich the layer of biological sample firmly on the electrode surface. Cyclic voltammetry (CV) analyses revealed a well-defined reduction peak for haemoglobin at about -0.30 V (vs. Ag/AgCl) at the red blood cell (GC-Nf-RBC-3Nf) and blood (GC-Nf-B-3Nf) film modified GCE in a pH 3.5 phosphate buffer solution. We further demonstrated that the complex biological conditions of a human red blood cell displayed no interference with the detection of haemoglobin. Such findings shall have an implication on the possibilities of studying the electrochemical behaviour of haemoglobin directly from human blood, for various scientific and clinical purposes.

  5. From Red Cells to Skiing to a New Concept for a Train

    NASA Astrophysics Data System (ADS)

    Weinbaum, Sheldon

    2003-11-01

    Although a red cell differs in size by 15 orders of magnitude from a human skier there is a remarkable dynamic similarity between a red gliding on the 0.4 nm thick endothelial surface matrix (glycocalyx) that lines our capillaries and a human skiing on fresh snow powder. We shall first show that in both cases one can generate lift forces that are 3 to 4 orders of magnitude greater than ordinary lubrication theory, but the red cell is a far more efficient skier since it does not dissipate its excess pressure at its lateral edges. The glycocalyx also exhibits several other extraordinary properties. It's fibers serve as an exquisitely designed mechanotranducer that can transmit fluid shearing stresses at its edge to the cortical cytoskeleton of the endothelial cell in initiating intracellular signalling. However, their resistance to buckling during red cell arrest is negligible compared to the fluid draining pressure. Our model suggests that the latter is the secret to why even slow moving red cells can move through our capillaries with miniscule friction from the solid phase. Finally, the small elastic restoring force of the fibers allows rapid restoration of the layer after the cell has passed. These basic concepts are used to design a new kind of train that we have called the "goose down express" whose cars ride on a track whose properties mimic the endothelial surface layer. Weinbaum et al. (2003) PNAS vol. 100, pp. 7988-7995.

  6. Biochemical Storage Lesions Occurring in Nonirradiated and Irradiated Red Blood Cells: A Brief Review

    PubMed Central

    Adams, F.; Bellairs, G.; Bird, A. R.; Oguntibeju, O. O.

    2015-01-01

    Red blood cells undergo a series of biochemical fluctuations during 35–42-day storage period at 1°C to 6°C. The sodium/potassium pump is immobilised causing a decrease in intracellular potassium with an increase in cytoplasmic sodium levels, glucose levels decline, and acidosis occurs as a result of low pH levels. The frailty of stored erythrocytes triggers the formation of haemoglobin-containing microparticles and the release of cell-free haemoglobin which may add to transfusion difficulties. Lipid peroxidation, oxidative stress to band 3 structures, and other morphological and structural molecular changes also occur leading to spheroechinocytes and osmotic fragility. These changes that transpire in the red cells during the storage period are referred to as “storage lesions.” It is well documented that gamma irradiation exacerbates storage lesions and the reports of increased potassium levels leading to adverse reactions observed in neonates and infants have been of particular concern. There are, however, remarkably few systematic studies comparing the in vitro storage lesions of irradiated and nonirradiated red cell concentrates and it has been suggested that the impact of storage lesions on leucocyte reduced red blood cell concentrate (RBCC) is incomplete. The review examines storage lesions in red blood cells and their adverse effects in reference to blood transfusion. PMID:25710038

  7. A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode

    PubMed Central

    Faes, Antonin; Hessler-Wyser, Aïcha; Zryd, Amédée; Van Herle, Jan

    2012-01-01

    Solid oxide fuel cells are able to convert fuels, including hydrocarbons, to electricity with an unbeatable efficiency even for small systems. One of the main limitations for long-term utilization is the reduction-oxidation cycling (RedOx cycles) of the nickel-based anodes. This paper will review the effects and parameters influencing RedOx cycles of the Ni-ceramic anode. Second, solutions for RedOx instability are reviewed in the patent and open scientific literature. The solutions are described from the point of view of the system, stack design, cell design, new materials and microstructure optimization. Finally, a brief synthesis on RedOx cycling of Ni-based anode supports for standard and optimized microstructures is depicted. PMID:24958298

  8. Recurrent gastrointestinal bleeding diagnosed by delayed scintigraphy with Tc-99m-labeled red blood cells.

    PubMed

    Nwakanma, Lois; Meyerrose, Gary; Kennedy, Shalyn; Rakvit, Ariwan; Bohannon, Todd; Silva, Micheal

    2003-08-01

    A 56-year-old woman presented with bright-red blood from the rectum. Esophagogastroduodenoscopy revealed mild gastritis. Colonoscopy demonstrated diverticulosis without active bleeding, and in vitro tagged red blood cell scintigraphy was unremarkable. There was no further evidence of bleeding and the patient was discharged home. The patient returned with recurrent bright-red blood from the rectum. Although delayed scintigraphic images seldom demonstrate the site of bleeding, delayed images at 12 hours demonstrated active bleeding near the hepatic flexure in this patient. This was confirmed with selective mesenteric angiography, and was treated with coil embolization of the tertiary branches of the right middle colic artery. PMID:12897664

  9. Bridging channel dendritic cells induce immunity to transfused red blood cells.

    PubMed

    Calabro, Samuele; Gallman, Antonia; Gowthaman, Uthaman; Liu, Dong; Chen, Pei; Liu, Jingchun; Krishnaswamy, Jayendra Kumar; Nascimento, Manuela Sales L; Xu, Lan; Patel, Seema R; Williams, Adam; Tormey, Christopher A; Hod, Eldad A; Spitalnik, Steven L; Zimring, James C; Hendrickson, Jeanne E; Stowell, Sean R; Eisenbarth, Stephanie C

    2016-05-30

    Red blood cell (RBC) transfusion is a life-saving therapeutic tool. However, a major complication in transfusion recipients is the generation of antibodies against non-ABO alloantigens on donor RBCs, potentially resulting in hemolysis and renal failure. Long-lived antibody responses typically require CD4(+) T cell help and, in murine transfusion models, alloimmunization requires a spleen. Yet, it is not known how RBC-derived antigens are presented to naive T cells in the spleen. We sought to answer whether splenic dendritic cells (DCs) were essential for T cell priming to RBC alloantigens. Transient deletion of conventional DCs at the time of transfusion or splenic DC preactivation before RBC transfusion abrogated T and B cell responses to allogeneic RBCs, even though transfused RBCs persisted in the circulation for weeks. Although all splenic DCs phagocytosed RBCs and activated RBC-specific CD4(+) T cells in vitro, only bridging channel 33D1(+) DCs were required for alloimmunization in vivo. In contrast, deletion of XCR1(+)CD8(+) DCs did not alter the immune response to RBCs. Our work suggests that blocking the function of one DC subset during a narrow window of time during RBC transfusion could potentially prevent the detrimental immune response that occurs in patients who require lifelong RBC transfusion support. PMID:27185856

  10. Red Blood Cell Deformation Under Shear Flow: The Effect of Changing Cell Properties

    NASA Astrophysics Data System (ADS)

    Forsyth, Alison M.; Wan, Jiandi; Ristenpart, William D.; Stone, Howard A.

    2008-11-01

    The deformability of red blood cells plays a major role in the pathology of several diseases, including malaria, sickle cell anemia and spherocytosis. Moreover, deformations are believed to trigger the release of adenosine triphosphate, which helps regulate vascular tone and is consequently an important factor in various vascular diseases. Here we investigate single-cell viscoelastic responses to increased shear stress in poly(dimethylsiloxane) channels with a single constriction 2-4 times larger than a typical erythrocyte. These channels mimic arteriole-sized vessels, and have the advantage that the cell membrane is not in contact with the channel walls which have vastly different mechanical and material properties than living tissue. High-speed video and image analysis were used to quantify the trajectories and deformations of cells exposed to varied doses of diamide, a chemical known to ``rigidify'' erythrocytes. Our results show that (i) deformation is proportional to shear rate and (ii) the deformability of diamide-treated cells is greater than that of untreated cells. The latter is an unforeseen result because micropipette aspiration experiments have shown the opposite. We expect that the experimental procedure described here will be useful for characterizing the effect of different therapeutic agents on cellular deformability.

  11. Red blood cell cluster separation from digital images for use in sickle cell disease.

    PubMed

    González-Hidalgo, Manuel; Guerrero-Peña, F A; Herold-García, S; Jaume-I-Capó, Antoni; Marrero-Fernández, P D

    2015-07-01

    The study of cell morphology is an important aspect of the diagnosis of some diseases, such as sickle cell disease, because red blood cell deformation is caused by these diseases. Due to the elongated shape of the erythrocyte, ellipse adjustment and concave point detection are applied widely to images of peripheral blood samples, including during the detection of cells that are partially occluded in the clusters generated by the sample preparation process. In the present study, we propose a method for the analysis of the shape of erythrocytes in peripheral blood smear samples of sickle cell disease, which uses ellipse adjustments and a new algorithm for detecting notable points. Furthermore, we apply a set of constraints that allow the elimination of significant image preprocessing steps proposed in previous studies. We used three types of images to validate our method: artificial images, which were automatically generated in a random manner using a computer code; real images from peripheral blood smear sample images that contained normal and elongated erythrocytes; and synthetic images generated from real isolated cells. Using the proposed method, the efficiency of detecting the two types of objects in the three image types exceeded 99.00%, 98.00%, and 99.35%, respectively. These efficiency levels were superior to the results obtained with previously proposed methods using the same database, which is available at http://erythrocytesidb.uib.es/. This method can be extended to clusters of several cells and it requires no user inputs. PMID:25216490

  12. Ion channels in human red blood cell membrane: actors or relics?

    PubMed

    Thomas, Serge L Y; Bouyer, Guillaume; Cueff, Anne; Egée, Stéphane; Glogowska, Edyta; Ollivaux, Céline

    2011-04-15

    During the past three decades, electrophysiological studies revealed that human red blood cell membrane is endowed with a large variety of ion channels. The physiological role of these channels, if any, remains unclear; they do not participate in red cell homeostasis which is rather based on the almost total absence of cationic permeability and minute anionic conductance. They seem to be inactive in the "resting cell." However, when activated experimentally, ion channels can lead to a very high single cell conductance and potentially induce disorders, with the major risks of fast dehydration and dissipation of gradients. Could there be physiological conditions under which the red cell needs to activate these high conductances, or are ion channels relics of a function lost in anucleated cells? It has been demonstrated that they play a key role in diseases such as sickle cell anemia or malaria. This short overview of ion channels identified to-date in the human red cell membrane is an attempt to propose a dynamic role for these channels in circulating cells in health and disease. PMID:21429775

  13. Red blood cells are a sink for interleukin 8, a leukocyte chemotaxin.

    PubMed

    Darbonne, W C; Rice, G C; Mohler, M A; Apple, T; Hébert, C A; Valente, A J; Baker, J B

    1991-10-01

    IL-8 (also known as neutrophil-activating peptide 1) is recognized as a potent effector of neutrophil functions. Several different cell types that contact blood, namely T lymphocytes, monocytes, and endothelial cells, secrete this polypeptide following stimulation by cytokines, or lipopolysaccharide. Here we show that when IL-8 is added to blood it rapidly partitions from the plasma fluid to the blood cells and that erythrocytes account for the vast majority of this binding. Analysis of 125I-IL-8 binding [( ala-IL-8]77 form) to human red cells indicates a single, 5 nM Kd affinity class of binding sites, present at approximately 2,000 per red cell representing approximately 15 nmol of red cell IL-8 binding sites per liter of blood. These sites are protease sensitive. Their binding of IL-8 is rapidly reversible and does not result in receptor internalization, although bound IL-8 is resistant to extraction by pH 3 buffer at 5 degrees C. 125I-IL-8 binding to red cells was not inhibited by epidermal growth factor or interleukin 1, but was inhibited by monocyte chemotactic peptide-1, which is not a neutrophil chemotaxin, but is a member of the same family of polypeptides as IL-8. FACS analysis of IL-8-mediated mobilization of Ca2+ in neutrophils indicates that the IL-8 bound to red cells is incapable of stimulating neutrophils. Thus, red cell absorption of IL-8 may function to limit stimulation of leukocytes by IL-8 released into blood. PMID:1918386

  14. Further observations on the specific red cell adherence test: effects of radiation therapy

    SciTech Connect

    Richie, J.P.; Yap, W.T.

    1981-04-01

    To assess the effects of radiation therapy on the specific red cell adherence test we have evaluated 33 patients who underwent cystectomy for bladder cancer and in whom radiotherapy had been used. With this test negative tumors were found in 32 of the 33 cases. In a second series of 10 patients histologic examinations were done by biopsy before radiotherapy and by subsequent microscopic examination of the cystectomy specimen. The specific red cell adherence test results remained constant in all of these cases. These findings strongly suggest that 1) the specific red cell adherence test does remain negative after radiotherapy and 2) this test is a valuable prognosticator of the future likelihood of invasion in all patients with transitional cell carcinoma of the bladder.

  15. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    DOEpatents

    Bitensky, M.W.; Yoshida, Tatsuro

    1998-08-04

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4 C storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4 C for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials. 8 figs.

  16. Prolonged cold storage of red blood cells by oxygen removal and additive usage

    DOEpatents

    Bitensky, Mark W.; Yoshida, Tatsuro

    1998-01-01

    Prolonged cold storage of red blood cells by oxygen removal and additive usage. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. The improved in vivo survival and the preservation of adenosine triphosphate levels, along with reduction in hemolysis and membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time, is achieved by reducing the oxygen level therein at the time of storage; in particular, by flushing the cells with an inert gas, and storing them in an aqueous solution which includes adenine, dextrose, mannitol, citrate ion, and dihydrogen phosphate ion, but no sodium chloride, in an oxygen-permeable container which is located in an oxygen-free environment containing oxygen-scavenging materials.

  17. Coarse-Grained Molecular Dynamics Simulation of a Red Blood Cell

    NASA Astrophysics Data System (ADS)

    Jiang, Li-Guo; Wu, Heng-An; Zhou, Xiao-Zhou; Wang, Xiu-Xi

    2010-02-01

    A worm-like chain model based on a spectrin network is employed to study the biomechanics of red blood cells. Coarse-grained molecular dynamics simulations are performed to obtain a stable configuration free of external loadings. We also discuss the influence of two parameters: the average bending modulus and the persistence length. The change in shape of a malaria-infected red blood cell can contribute to the change in its molecular-based structure. As the persistence length of the membrane network in the infected red blood cell decreases, the deformability decreases and the biconcave shape is destroyed. The numerical results are comparable with previously reported experimental results. The coarse-grained model can be used to study the relationship between macro-mechanical properties and molecular-scale structures of cells.

  18. Vesicles and red blood cells in flow: From individual dynamics to rheology

    NASA Astrophysics Data System (ADS)

    Vlahovska, Petia M.; Podgorski, Thomas; Misbah, Chaouqi

    2009-11-01

    The rheology of suspensions of soft particles, such as red blood cells, is a long-standing problem in science and engineering due to the complex interplay between deformable microstructure and the macroscale flow. The major challenge stems from the free-boundary nature of the particle interface. Lipid bilayer membranes that envelop cells and vesicles are particularly complex interfaces because of their unusual mechanics: the molecularly thin membrane is a highly-flexible incompressible fluid sheet. As a result, particles made of closed lipid bilayers (red cells and vesicles) can exhibit richer dynamics than would capsules and drops. We overview the key experimental observations and recent advances in the theoretical modeling of the vesicles and red blood cells in flow. To cite this article: P.M. Vlahovska et al., C. R. Physique 10 (2009).

  19. Holoprosencephaly and Pure Red Cell Aplasia in a Feline Leukaemia Virus-Positive Kitten.

    PubMed

    Southard, T L; Rodriguez-Ramos Fernandez, J; Priest, H; Stokol, T

    2016-01-01

    A 9-month-old, female, domestic longhair cat with severe anaemia tested positive for feline leukaemia virus (FeLV) and was humanely destroyed and submitted for necropsy examination. Gross findings included a non-divided rostral telencephalon, consistent with semilobar holoprosencephaly. Histological examination of the bone marrow revealed an almost complete absence of erythroid precursor cells, consistent with pure red cell aplasia, and mild to moderate myelofibrosis. This case demonstrates a very unusual central nervous system defect, as well as an atypical presentation of pure red cell aplasia, in a FeLV-positive kitten. PMID:26897097

  20. Sphero-echinocytosis of human red blood cells caused by snake, red-back spider, bee and blue-ringed octopus venoms and its inhibition by snake sera.

    PubMed

    Flachsenberger, W; Leigh, C M; Mirtschin, P J

    1995-06-01

    It was found that bee (Apis mellifera) venom, red-back spider (Latrodectus mactans) venom, blue-ringed octopus (Hapalochlaena maculosa) venom, ten different snake venoms, phospholipase A2 and four snake toxins caused sphero-echinocytosis of human red blood cells at 200 ng/ml. Most venoms and toxins lost the ability to deform human red blood cells when their components of less than mol. wt 10,000 were applied. In a number of cases the sphero-echinocytotic effect was also inhibited by blood sera of Notechis scutatus and Pseudonaja textilis. PMID:7676470

  1. Erythropoietin withdrawal alters interactions between young red blood cells, splenic endothelial cells, and macrophages: an in vitro model of neocytolysis

    NASA Technical Reports Server (NTRS)

    Trial, J.; Rice, L.; Alfrey, C. P.

    2001-01-01

    BACKGROUND: We have described the rapid destruction of young red blood cells (neocytolysis) in astronauts adapting to microgravity, in polycythemic high altitude dwellers who descend to sea level, and in patients with kidney disorders. This destruction results from a decrease in erythropoietin (EPO) production. We hypothesized that such EPO withdrawal could trigger physiological changes in cells other than red cell precursors and possibly lead to the uptake and destruction of young red cells by altering endothelial cell-macrophage interactions, most likely occurring in the spleen. METHODS: We identified EPO receptors on human splenic endothelial cells (HSEC) and investigated the responses of these cells to EPO withdrawal. RESULTS: A monolayer of HSEC, unlike human endothelial cells from aorta, glomerulus, or umbilical vein, demonstrated an increase in permeability upon EPO withdrawal that was accompanied by unique morphological changes. When HSEC were cultured with monocyte-derived macrophages (but not when either cell type was cultured alone), EPO withdrawal induced an increased ingestion of young red cells by macrophages when compared with the constant presence or absence of EPO. CONCLUSIONS: HSEC may represent a unique cell type that is able to respond to EPO withdrawal by increasing permeability and interacting with phagocytic macrophages, which leads to neocytolysis.

  2. Estimation of transfused red cell survival using an enzyme-linked antiglobulin test

    SciTech Connect

    Kickler, T.S.; Smith, B.; Bell, W.; Drew, H.; Baldwin, M.; Ness, P.M.

    1985-09-01

    An enzyme-linked antiglobulin test (ELAT) method was developed to estimate survival of transfused red cells. This procedure is based on a principle analogous to that of the Ashby technique were antigenically distinct red cells are transfused and their survival studied. The authors compared the ELAT survival to the V Chromium method (V Cr) in four patients. Three patients with hypoproliferative anemias showed T 1/2 by ELAT of 17.5, 18, and 17 days versus 18.5, 20, and 19 days by the V Cr method. A fourth patient with traumatic cardiac hemolysis had two studies performed. In this case, the ELAT showed a T 1/2 of 10 and 8.1 days while V Cr T 1/2 values were 11 and 10.5 days. The ELAT method for measuring red cell survival yielded data which agreed closely with the results of the V Cr method. Although V Cr is the accepted method for red cell survival, the ELAT method can be used to estimate transfused red cell survival.

  3. Nitric Oxide Synthetic Pathway in Red Blood Cells Is Impaired in Coronary Artery Disease

    PubMed Central

    Eligini, Sonia; Porro, Benedetta; Lualdi, Alessandro; Squellerio, Isabella; Veglia, Fabrizio; Chiorino, Elisa; Crisci, Mauro; Garlaschè, Anna; Giovannardi, Marta; Werba, Josè-Pablo; Tremoli, Elena; Cavalca, Viviana

    2013-01-01

    Background All the enzymatic factors/cofactors involved in nitric oxide (NO) metabolism have been recently found in red blood cells. Increased oxidative stress impairs NO bioavailability and has been described in plasma of coronary artery disease (CAD) patients. The aim of the study was to highlight a potential dysfunction of the metabolic profile of NO in red blood cells and in plasma from CAD patients compared with healthy controls. Methods We determined L-arginine/NO pathway by liquid-chromatography tandem mass spectrometry and high performance liquid chromatography methods. The ratio of oxidized and reduced forms of glutathione, as index of oxidative stress, was measured by liquid-chromatography tandem mass spectrometry method. NO synthase expression and activity were evaluated by immunofluorescence staining and ex-vivo experiments of L-[15N2]arginine conversion to L-[15N]citrulline respectively. Results Increased amounts of asymmetric and symmetric dimethylarginines were found both in red blood cells and in plasma of CAD patients in respect to controls. Interestingly NO synthase expression and activity were reduced in CAD red blood cells. In contrast, oxidized/reduced glutathione ratio was increased in CAD and was associated to arginase activity. Conclusion Our study analyzed for the first time the whole metabolic pathway of L-arginine/NO, both in red blood cells and in plasma, highlighting an impairment of NO pathway in erythrocytes from CAD patients, associated with decreased NO synthase expression/activity and increased oxidative stress. PMID:23940508

  4. Direct measurements of membrane potential and membrane resistance of human red cells

    PubMed Central

    Lassen, U. V.; Sten-Knudsen, O.

    1968-01-01

    1. In order to evaluate the membrane potentials calculated from the distribution of chloride ions in human red cells and plasma, it is desirable to have a direct measurement of the transmembrane potential of these cells. 2. A method has been devised for introducing a capillary micro-electrode into human red cells. The method allows simultaneous measurements of potential and membrane resistance with only one micro-electrode located in the cell. 3. Upon impalement of single cells in plasma, a scatter of membrane potentials and of resistance values was obtained. The potential drop never exceeded -14 mV and the maximum resistances were about 7 Ω. cm2. Positive potentials were obtained on impalement of red cell aggregates. 4. Arguments are given to support the view that it is in these cells which suffer least damage from the impalement that maximum values of membrane potentials and resistances are observed. The errors caused by the change in the liquid junction during the impalement have been estimated. 5. As judged from this study, it seems permissible under normal conditions to calculate the membrane potential of the red cell from the chloride concentrations in plasma and in intracellular water. PMID:5649641

  5. Measurement of the distribution of anion exchange function in normal human red cells.

    PubMed Central

    Raftos, J E; Bookchin, R M; Lew, V L

    1997-01-01

    1. The aim of the present work was to investigate cell-to-cell variation in anion exchange turnover in normal human red cells. Red cells permeabilized to protons and K+ dehydrate extremely rapidly by processes that are rate-limited by the induced K+ permeability or by anion exchange turnover. Conditions were designed to render dehydration rate-limited by anion exchange turnover. Cell-to-cell variation in anion exchange function could then be measured from the distribution of delay times required for dehydrating cells to attain resistance to haemolysis in a selected hypotonic medium. 2. Red cells were suspended at 10% haematocrit in a low-K+ solution and, after a brief preincubation with 20 microM SITS at 4 degrees C, were warmed to 24 degrees C, and the protonophore CCCP was added (20 microM) followed 2 min later by valinomycin (60 microM). Delay times for cells to become resistant to lysis were measured from the instant of valinomycin addition by sampling suspension aliquots into thirty volumes of 35 mM NaCl. After centrifugation the per cent lysis was estimated by measuring the haemoglobin concentration in the supernatant. Typical median delay times with this standardized method were 4-5 min. 3. The statistical parameters of the delay time distributions report the population spread in the transport function that was limiting to dehydration. In the absence of SITS and CCCP, dehydration was limited by the diffusional Cl- permeability (PCl). Delay time distributions for PCl- and anion exchange-limited dehydration were measured in red cells from three normal donors. For both distributions, the coefficients of variation ranged between 13.0 and 15.2%, indicating a high degree of uniformity in PCl and anion exchange function among individual red cells. PMID:9061637

  6. 99mTc-red blood cells SPECT and planar scintigraphy in the diagnosis of hepatic hemangiomas.

    PubMed

    Artiko, M V; Sobić-Saranović, P D; Perisić-Savić, S M; Stojković, V M; Radoman, B I; Knezević, S J; Petrović, S N; Obradović, B V; Milović, V

    2008-01-01

    The aim of the study is the assessment of the value of SPECT (single photon emission computerized tomography) using 99mTc-labeled red blood cells in the detection of liver hemangioma, in comparison to planar imaging. With planar red blood cell scintigraphy, sensitivity of the method was 76%, specificity 98%, positive predictive value 98% and negative predictive value 79%. With SPECT, sensitivity of the method was 95%, specificity 98%, positive predictive value 98% and negative predictive value 94%. The smallest lesion detected by planar red blood cell scintigraphy was 1.2 cm, and with SPECT red blood cell scintigraphy 0.8 cm. The use of 99mTc-labeled red blood cells SPECT improved the sensitivity much more in smaller lesions (0.8 to 2 cm), than in bigger ones (2-5 cm). SPECT with radiolabeled red blood cells significantlyy improves the results of scintigraphic findings, especially in the small lesions. PMID:19245136

  7. Microvascular blood flow resistance: Role of red blood cell migration and dispersion.

    PubMed

    Katanov, Dinar; Gompper, Gerhard; Fedosov, Dmitry A

    2015-05-01

    Microvascular blood flow resistance has a strong impact on cardiovascular function and tissue perfusion. The flow resistance in microcirculation is governed by flow behavior of blood through a complex network of vessels, where the distribution of red blood cells across vessel cross-sections may be significantly distorted at vessel bifurcations and junctions. In this paper, the development of blood flow and its resistance starting from a dispersed configuration of red blood cells is investigated in simulations for different hematocrit levels, flow rates, vessel diameters, and aggregation interactions between red blood cells. Initially dispersed red blood cells migrate toward the vessel center leading to the formation of a cell-free layer near the wall and to a decrease of the flow resistance. The development of cell-free layer appears to be nearly universal when scaled with a characteristic shear rate of the flow. The universality allows an estimation of the length of a vessel required for full flow development, lc ≲ 25D, for vessel diameters in the range 10 μm < D < 100 μm. Thus, the potential effect of red blood cell dispersion at vessel bifurcations and junctions on the flow resistance may be significant in vessels which are shorter or comparable to the length lc. Aggregation interactions between red blood cells generally lead to a reduction of blood flow resistance. The simulations are performed using the same viscosity for both external and internal fluids and the RBC membrane viscosity is not considered; however, we discuss how the viscosity contrast may affect the results. Finally, we develop a simple theoretical model which is able to describe the converged cell-free-layer thickness at steady-state flow with respect to flow rate. The model is based on the balance between a lift force on red blood cells due to cell-wall hydrodynamic interactions and shear-induced effective pressure due to cell-cell interactions in flow. We expect that these results can

  8. Attachment of antibody to biotinylated red blood cells: immuno-red blood cells display high affinity to immobilized antigen and normal biodistribution in rats.

    PubMed

    Muzykantov, V R; Murciano, J C

    1996-08-01

    Streptavidin-mediated attachment of biotinylated antibodies (b-Ab) to biotinylated red blood cells (b-RBC) is useful for preparation of immuno-red blood cells, a prospective vehicle for drug targeting. However, streptavidin (SA) induces lysis of extensively biotinylated RBC by complement due to cross-linking and inactivation of RBC complement regulators. To reduce cross-linking of RBC membrane proteins, we utilized mild biotinylation of RBC with 20 microM biotin ester (b20-RBC). SA effectively binds to rat b20-RBC (10(5) SA molecules/cell) and provides for following attachment of 5 x 10(4) molecules of b-IgG/SA per b20-RBC. By in vitro assay, b-Ab/SA/b20-RBC were stable in fresh rat serum. Serum-stable immuno-red blood cells (b-Ab/SA/b20-RBC) specifically bound to antigen-coated surfaces, but not to BSA-coated surfaces. Biodistribution of 51Cr-labelled b-Ab/SA/b20-RBC in rats was similar to that of control RBC, with no indication of lysis in vivo. These results suggest b-Ab/SA/b20-RBC may be explored as a vehicle for drug targeting. PMID:8756393

  9. In vitro metabolism study of normal and tumor cells when exposed to red LED light

    NASA Astrophysics Data System (ADS)

    Stolbovskaya, Olga V.; Khairullin, Radik M.; Saenko, Yuri V.; Krasnikova, Ekaterina S.; Krasnikov, Aleksandr V.; Fomin, Aleksandr A.; Skaptsov, Aleksandr A.

    2016-04-01

    This work presents the results of studying the mitochondrial membrane potential, intracellular ROS, peculiarities of the cell cycle of cancer cells HCT-116 and the normal line of CHO cells when exposed to the red LED light with a wavelength range of 0.620-0.680 μm. A dose-dependent increase in mitochondrial membrane potential and intracellular ROS concentration in cancer cells HCT-116 was established. In normal CHO cell line a dose-dependent reduction of mitochondrial membrane potential and dose-dependent increase in intracellular ROS occur. It has been shown that the sensitivity of the studied cell lines to the red light depends on the stage of the cell cycle.

  10. Laser viability method for red blood cell-state monitoring

    NASA Astrophysics Data System (ADS)

    Lapotko, Dmitry; Kuchinsky, Georgy; Antonishina, Elena; Scoromnik, Elena

    1996-01-01

    The method for RBC state control is based upon single cell viability control after illumination with laser pulse. Heat shock resulting from absorption of laser energy by a cell is considered as a cell load. This load acts from inside of the cell, is pulsed (10-5) and can be delivered directly to the chosen cells. The result of each illumination as cell survival or damage is controlled optically by monitoring the cells' response on a pulse through photothermal technique. Under fixed laser parameters the percentage of damaged cells is viability index (VI) for a certain cell population. The testing procedure includes consequential illumination of each cell in population and calculation of VI. Experimental set up is based upon optical microscope. Dual laser thermal lens technique is used for cell illumination and monitoring. For cell loading 5 ns pulses, 400 divided by 600 nm with energies up to 20 (mu) J are generated by tunable dye laser. Cell monitoring is realized with cw He-Ne (632.8 nm) laser and photodetector. All data acquisition routines are automated. Up to 3 cell suspensions can be studied in a multisample chamber designed to secure cells. An amount of cell suspension required is 1 (mu) l. One population test at a fixed wavelength takes 2 divided by 3 min. In experiments with rats, treated with LPS E. Coli injection to stimulate fever and a septic stress we found that variation of RBC viability becomes apparent in 20 - 30 min after injection, while the clinical changes (blood pressure, body temperature, skin temperature) become detectable after 1 hour. The results obtained show that the method can reveal additional properties of the cells most abundant for monitoring and diagnostic tasks.

  11. Effect of cell ageing on Ca2+ influx into human red cells.

    PubMed

    Romero, P J; Romero, E A

    1999-01-01

    The effect of cell ageing on Ca2+ entry was studied in this work, using sub-populations of young and old human red cells, separated by stringent percoll density gradients. Additionally, the influence of an osmotic gradient was investigated as a model for shear stress. Ca2+ entry was assessed at 37 degrees C, under conditions where the Ca2+ pump was either inhibited by NaVO3 (0.5-10 mM) or inactivated by ATP depletion. The entry was linear with time up to 1 h. No differences in Ca2+ influx between the two sub-populations were detected in isotonic Na(+)-medium. In contrast, after incubation in anisosmotic media, Ca2+ entry into old cells was significantly higher than into younger cells. In hypotonic Na(+)-medium, the entry into old cells was not affected by La3+ (10 microM) whilst it was partially blocked by Gd3+ at a similar level (half-maximal effect attained with about 1 microM Gd3+). The entry into young cells was only slightly stimulated by these lanthanides at low concentrations (10 microM), regardless of the tonicity of incubation medium. Further increasing Gd3+ levels above 10 microM markedly enhanced Ca2+ entry into both cell types. The selective blockade of Ca2+ influx by low Gd3+ concentrations suggests presence of mechano-sensitive channels, that become preferentially activated in old cells. Activation of these channels during in-vivo microcirculation may help to explain the increased Ca2+ content of senescent cells. PMID:10598277

  12. Differential effects of temperature on three components of passive permeability to potassium in rodent red cells.

    PubMed Central

    Hall, A C; Willis, J S

    1984-01-01

    The effect of temperature on ouabain-insensitive fluxes of K+ was characterized in red cells from a non-hibernator (guinea-pig) and a hibernator (thirteen-lined ground squirrel). The residual K+ influx which remains in the presence of ouabain and bumetanide, and which is linearly dependent on [K+]o was the same in the erythrocytes of the two species at low temperature (5 degrees C). At 5 degrees C co-transport of K+ was abolished in guinea-pig red cells but was still present in ground squirrel red cells. In guinea-pig cells, ouabain-and-bumetanide-insensitive K+ flux was increased by Ca2+ at low temperatures. This flux was inhibited by quinine and selective for K+ over Na+, indicating activation of the Ca2+-sensitive K+ pathway (Gárdos channel). Ouabain-and-bumetanide-insensitive K+ permeability in red cells from the ground squirrel was insensitive to Ca2+ added to the medium at low temperature. When ground squirrel red cells were depleted of ATP or treated with A23187, Ca2+ induced a flux which was inhibitable by quinine. Hence, ground squirrel red cells possess Gárdos channels. The temperature sensitivity of the K+ channels was assessed using A23187-mediated K+ influx as a measure of Gárdos channel activation. The influence of temperature on the Ca2+-stimulated K+ fluxes under these conditions was indistinguishable between the two species. It is concluded that K+ loss through the Ca2+-sensitive K+ channel is minimal in hibernators' erythrocytes because of more efficient regulation of cytoplasmic Ca2+ during cold storage. PMID:6325676

  13. Genomewide scans of red cell indices suggest linkage on chromosome 6q23

    PubMed Central

    Iliadou, A; Evans, D M; Zhu, G; Duffy, D L; Frazer, I H; Montgomery, G W; Martin, N G

    2007-01-01

    Background The red cell indices quantify the size, number and oxygen‐carrying ability of erythrocytes. Although the genetic basis of many monogenic forms of anaemia is well understood, comparatively little is known about the genes responsible for variation in the red cell indices among healthy participants. Objective To identify quantitative trait loci (QTLs) responsible for normal variation in the red cell indices of 391 pairs of dizygotic twins who were measured longitudinally at 12, 14 and 16 years of age. Results Evidence suggesting linkage of red cell indices to haemoglobin concentration (LOD  = 3.03) and haematocrit (LOD  = 2.95) on chromosome 6q23, a region previously identified as possibly harbouring a QTL for haematocrit, was found. Evidence for linkage to several other regions of the genome, including chromosome 4q32 for red cell count and 7q for mean cell volume, was also found. In contrast, there was little evidence of linkage to the chromosomal regions containing the genes for erythropoietin (7q21) and its receptor (19p13.2), nor to the regions containing the genes for the haemoglobin α (16p13.3) and β chains (11p15.5). Conclusion Findings provide additional evidence for a QTL affecting haemoglobin and haematocrit on chromosome 6q23. In contrast, polymorphisms in the genes coding for erythropoietin, its receptor and the haemoglobin α and β chains do not appear to contribute substantially to variation in the red cell indices between healthy persons. PMID:16950815

  14. Kin Discrimination in Protists: From Many Cells to Single Cells and Backwards.

    PubMed

    Paz-Y-Miño-C, Guillermo; Espinosa, Avelina

    2016-05-01

    During four decades (1960-1990s), the conceptualization and experimental design of studies in kin recognition relied on work with multicellular eukaryotes, particularly Unikonta (including invertebrates and vertebrates) and some Bikonta (including plants). This pioneering research had an animal behavior approach. During the 2000s, work on taxa-, clone- and kin-discrimination and recognition in protists produced genetic and molecular evidence that unicellular organisms (e.g. Saccharomyces, Dictyostelium, Polysphondylium, Tetrahymena, Entamoeba and Plasmodium) could distinguish between same (self or clone) and different (diverse clones), as well as among conspecifics of close or distant genetic relatedness. Here, we discuss some of the research on the genetics of kin discrimination/recognition and highlight the scientific progress made by switching emphasis from investigating multicellular to unicellular systems (and backwards). We document how studies with protists are helping us to understand the microscopic, cellular origins and evolution of the mechanisms of kin discrimination/recognition and their significance for the advent of multicellularity. We emphasize that because protists are among the most ancient organisms on Earth, belong to multiple taxonomic groups and occupy all environments, they can be central to reexamining traditional hypotheses in the field of kin recognition, reformulating concepts, and generating new knowledge. PMID:26873616

  15. Simulations of molecular diffusion in lattices of cells: insights for NMR of red blood cells.

    PubMed Central

    Regan, David G; Kuchel, Philip W

    2002-01-01

    The pulsed field-gradient spin-echo (PGSE) nuclear magnetic resonance (NMR) experiment, conducted on a suspension of red blood cells (RBC) in a strong magnetic field yields a q-space plot consisting of a series of maxima and minima. This is mathematically analogous to a classical optical diffraction pattern. The method provides a noninvasive and novel means of characterizing cell suspensions that is sensitive to changes in cell shape and packing density. The positions of the features in a q-space plot characterize the rate of exchange across the membrane, cell dimensions, and packing density. A diffusion tensor, containing information regarding the diffusion anisotropy of the system, can also be derived from the PGSE NMR data. In this study, we carried out Monte Carlo simulations of diffusion in suspensions of "virtual" cells that had either biconcave disc (as in RBC) or oblate spheroid geometry. The simulations were performed in a PGSE NMR context thus enabling predictions of q-space and diffusion tensor data. The simulated data were compared with those from real PGSE NMR diffusion experiments on RBC suspensions that had a range of hematocrit values. Methods that facilitate the processing of q-space data were also developed. PMID:12080109

  16. A biomimetic microfluidic chip to study the circulation and mechanical retention of red blood cells in the spleen.

    PubMed

    Picot, Julien; Ndour, Papa Alioune; Lefevre, Sophie D; El Nemer, Wassim; Tawfik, Harvey; Galimand, Julie; Da Costa, Lydie; Ribeil, Jean-Antoine; de Montalembert, Mariane; Brousse, Valentine; Le Pioufle, Bruno; Buffet, Pierre; Le Van Kim, Caroline; Français, Olivier

    2015-04-01

    Red blood cells (RBCs) are deformable and flow through vessels narrower than their own size. Their deformability is most stringently challenged when they cross micrometer-wide slits in the spleen. In several inherited or acquired RBC disorders, blockade of small vessels by stiff RBCs can trigger organ damage, but a functional spleen is expected to clear these abnormal RBCs from the circulation before they induce such complications. We analyzed flow behavior of RBCs in a microfluidic chip that replicates the mechanical constraints imposed on RBCs as they cross the human spleen. Polymer microchannels obtained by soft lithography with a hydraulic diameter of 25 μm drove flow into mechanical filtering units where RBCs flew either slowly through 5- to 2-μm-wide slits or rapidly along 10-μm-wide channels, these parallel paths mimicking the splenic microcirculation. Stiff heated RBCs accumulated in narrow slits seven times more frequently than normal RBCs infused simultaneously. Stage-dependent retention of Plasmodium falciparum-infected RBCs was also observed in these slits. We also analyzed RBCs from patients with hereditary spherocytosis and observed retention for those having the most altered mechanical properties as determined by ektacytometry. Thus, in keeping with previous observations in vivo and ex vivo, the chip successfully discriminated poorly deformable RBCs based on their distinct mechanical properties and on the intensity of the cell alteration. Applications to the exploration of the pathogenesis of malaria, hereditary spherocytosis, sickle cell disease and other RBC disorders are envisioned. PMID:25641515

  17. Anti-Erythropoietin Antibody Associated Pure Red Cell Aplasia Resolved after Liver Transplantation

    PubMed Central

    Hung, Annie K.; Guy, Jennifer; Behler, Caroline M.; Lee, Eugene E.

    2015-01-01

    Patients undergoing antiviral therapy for chronic hepatitis C often develop anemia secondary to ribavirin and interferon. Recombinant erythropoietin has been used to improve anemia associated with antiviral therapy and to minimize dose reductions, which are associated with decreased rates of sustained virologic response. A rare potential side effect of recombinant erythropoietin is anti-erythropoietin antibody associated pure red cell aplasia. In chronic kidney disease patients with this entity, there have been good outcomes associated with renal transplant and subsequent immunosuppression. In this case, a chronic liver disease patient developed anti-erythropoietin associated pure red cell aplasia and recovered after liver transplantation and immunosuppression. It is unclear whether it is the transplanted organ, the subsequent immunosuppression, or the combination that contributed to the response. In conclusion, anti-erythropoietin associated pure red cell aplasia is a serious complication of erythropoietin therapy, but this entity should not be considered a contraindication for solid organ transplantation. PMID:26240773

  18. Red Light-Regulated Reversible Nuclear Localization of Proteins in Mammalian Cells and Zebrafish.

    PubMed

    Beyer, Hannes M; Juillot, Samuel; Herbst, Kathrin; Samodelov, Sophia L; Müller, Konrad; Schamel, Wolfgang W; Römer, Winfried; Schäfer, Eberhard; Nagy, Ferenc; Strähle, Uwe; Weber, Wilfried; Zurbriggen, Matias D

    2015-09-18

    Protein trafficking in and out of the nucleus represents a key step in controlling cell fate and function. Here we report the development of a red light-inducible and far-red light-reversible synthetic system for controlling nuclear localization of proteins in mammalian cells and zebrafish. First, we synthetically reconstructed and validated the red light-dependent Arabidopsis phytochrome B nuclear import mediated by phytochrome-interacting factor 3 in a nonplant environment and support current hypotheses on the import mechanism in planta. On the basis of this principle we next regulated nuclear import and activity of target proteins by the spatiotemporal projection of light patterns. A synthetic transcription factor was translocated into the nucleus of mammalian cells and zebrafish to drive transgene expression. These data demonstrate the first in vivo application of a plant phytochrome-based optogenetic tool in vertebrates and expand the repertoire of available light-regulated molecular devices. PMID:25803699

  19. Detecting Newcastle disease virus in combination of RT-PCR with red blood cell absorption.

    PubMed

    Yi, Jianzhong; Liu, Chengqian

    2011-01-01

    Reverse transcription-polymerase chain reaction (RT-PCR) has limited sensitivity when treating complicated samples, such as feces, waste-water in farms, and nucleic acids, protein rich tissue samples, all the factors may interfere with the sensitivity of PCR test or generate false results. In this study, we developed a sensitive RT-PCR, combination of red blood cell adsorption, for detecting Newcastle disease virus (NDV). One pair of primers which was highly homologous to three NDV pathotypes was designed according to the consensus nucleocapsid protein (NP) gene sequence. To eliminate the interfere of microbes and toxic substances, we concentrated and purified NDV from varied samples utilizing the ability of NDV binding red blood cells (RBCs). The RT-PCR coupled with red blood cell adsorption was much more sensitive in comparison with regular RT-PCR. The approach could also be used to detect other viruses with the property of hemagglutination, such as influenza viruses. PMID:21535888

  20. Red cell volume with changes in plasma osmolarity during maximal exercise.

    NASA Technical Reports Server (NTRS)

    Van Beaumont, W.

    1973-01-01

    The volume of the red cell in vivo was measured during acute changes in plasma osmolarity evoked through short (6 to 8 min) maximal exercise in six male volunteer subjects. Simultaneous measurements of mean corpuscular red cell volume (MCV), hematocrit, blood hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and plasma osmolarity showed that there was no change in the MCV or MCHC with a concomitant rise of nearly 6% in plasma osmolarity. Apparently, in vivo, the volume of the red cell in exercising healthy human subjects does not change measurably, in spite of significant changes in osmotic pressure of the surrounding medium. Consequently, it is not justified to correct postexercise hematocrit measurements for changes in plasma osmolarity.

  1. A method for drying red blood cells for solid-phase immunoassay.

    PubMed

    Tamai, T; Mazda, T

    1999-12-01

    To develop a simpler and quicker alloantibody screening method, red cell stroma were bound and dried to microplate wells for use in magnetic-mixed passive haemagglutination (M-MPHA) tests. In the procedure of drying stroma, the Triton X-100-based haemolysing method gave lowest denaturation of red blood cells, and this method gave increased reactivity to Kidd and Rh antigens and clinically significant antibodies were detected as well as with the M-MPHA test. But long incubation with Triton X-100 and using high concentrations of Triton X-100 gave rise to some reduction in antigenicity, so the precise conditions for haemolysis are critical. This dried stroma-coated microplate can be stored for longer and more easily at room temperature than nondried intact red blood cells. The new system gave good sensitivity and the overall test time was shortened and should give a particular advantage for mass screening and for automation of this test. PMID:10583889

  2. Method for extending the useful shelf-life of refrigerated red blood cells by flushing with inert gas

    DOEpatents

    Bitensky, Mark W.; Yoshida, Tatsuro

    1997-01-01

    Method using oxygen removal for extending the useful shelf-life of refrigerated red blood cells. A cost-effective, 4.degree. C. storage procedure that preserves red cell quality and prolongs post-transfusion in vivo survival is described. Preservation of adenosine triphosphate levels and reduction in hemolysis and in membrane vesicle production of red blood cells stored at 4.degree. C. for prolonged periods of time is achieved by removing oxygen therefrom at the time of storage; in particular, by flushing with an inert gas. Adenosine triphosphate levels of the stored red blood cells are boosted in some samples by addition of ammonium phosphate.

  3. Quantitative non-invasive cell characterisation and discrimination based on multispectral autofluorescence features

    PubMed Central

    Gosnell, Martin E.; Anwer, Ayad G.; Mahbub, Saabah B.; Menon Perinchery, Sandeep; Inglis, David W.; Adhikary, Partho P.; Jazayeri, Jalal A.; Cahill, Michael A.; Saad, Sonia; Pollock, Carol A.; Sutton-McDowall, Melanie L.; Thompson, Jeremy G.; Goldys, Ewa M.

    2016-01-01

    Automated and unbiased methods of non-invasive cell monitoring able to deal with complex biological heterogeneity are fundamentally important for biology and medicine. Label-free cell imaging provides information about endogenous autofluorescent metabolites, enzymes and cofactors in cells. However extracting high content information from autofluorescence imaging has been hitherto impossible. Here, we quantitatively characterise cell populations in different tissue types, live or fixed, by using novel image processing and a simple multispectral upgrade of a wide-field fluorescence microscope. Our optimal discrimination approach enables statistical hypothesis testing and intuitive visualisations where previously undetectable differences become clearly apparent. Label-free classifications are validated by the analysis of Classification Determinant (CD) antigen expression. The versatility of our method is illustrated by detecting genetic mutations in cancer, non-invasive monitoring of CD90 expression, label-free tracking of stem cell differentiation, identifying stem cell subpopulations with varying functional characteristics, tissue diagnostics in diabetes, and assessing the condition of preimplantation embryos. PMID:27029742

  4. Quantitative non-invasive cell characterisation and discrimination based on multispectral autofluorescence features.

    PubMed

    Gosnell, Martin E; Anwer, Ayad G; Mahbub, Saabah B; Menon Perinchery, Sandeep; Inglis, David W; Adhikary, Partho P; Jazayeri, Jalal A; Cahill, Michael A; Saad, Sonia; Pollock, Carol A; Sutton-McDowall, Melanie L; Thompson, Jeremy G; Goldys, Ewa M

    2016-01-01

    Automated and unbiased methods of non-invasive cell monitoring able to deal with complex biological heterogeneity are fundamentally important for biology and medicine. Label-free cell imaging provides information about endogenous autofluorescent metabolites, enzymes and cofactors in cells. However extracting high content information from autofluorescence imaging has been hitherto impossible. Here, we quantitatively characterise cell populations in different tissue types, live or fixed, by using novel image processing and a simple multispectral upgrade of a wide-field fluorescence microscope. Our optimal discrimination approach enables statistical hypothesis testing and intuitive visualisations where previously undetectable differences become clearly apparent. Label-free classifications are validated by the analysis of Classification Determinant (CD) antigen expression. The versatility of our method is illustrated by detecting genetic mutations in cancer, non-invasive monitoring of CD90 expression, label-free tracking of stem cell differentiation, identifying stem cell subpopulations with varying functional characteristics, tissue diagnostics in diabetes, and assessing the condition of preimplantation embryos. PMID:27029742

  5. Temperatures associated with thermally induced red blood cell changes in tissues irradiated in vivo

    NASA Astrophysics Data System (ADS)

    Thomsen, Sharon L.; Schwartz, Jon A.; Joseph, Rachel; Pearce, John A.; Rae, Brian; McMurray, Tom J.

    1994-07-01

    Photothermal coagulation and ablation lesions were produced in exposed livers of anesthetized rats with a cw Nd:YAG laser ((lambda) equals1064 nm; beam power 3.2 to 10 W; exposure times 3 to 10 s, and spot diameter, 0.7 to 1.9 mm). The surface temperatures produced by the irradiations were derived from IR camera images calibrated with temperature controlled black bodies present in the scene. Targetoid lesions with central white and outer red zones marked areas of surface and deep coagulation grossly. The animals were sacrificed 30 minutes after irradiation. The lesions and surrounding normal liver were collected for light microscopy. Microscopically, characteristic, thermally-induced red blood cell alterations were found in the white and red zones and at the boundaries separating them. The boundaries of the concentric surface zones were measured grossly from the lesion centers and compared to the thermal images to determine the temperatures associated with the red blood cell changes. The temperatures for the surface and deep morphologic isotherms defined by the white/red and red/normal boundaries of rat liver irradiated in vivo are 68+/- 5.0 degree(s)C and 55+/- 2.7 degree(s)C.

  6. Brief report: a new profile of terminal N-acetyllactosamines glycans on pig red blood cells and different expression of alpha-galactose on Sika deer red blood cells and nucleated cells.

    PubMed

    Tan, Yingxia; Gong, Feng; Li, Subo; Ji, Shouping; Lu, Yanping; Gao, Hongwei; Xu, Hua; Zhang, Yangpei

    2010-05-01

    It has been reported that: (1) large variations were found in the number of sialic acid (SA) capped with N-acetyllactosamines (SA-Galbeta1-4GlcNAc-R) and alpha-Gal epitopes (Galalpha1-3Galbeta1-4GlcNAc-R) or uncapped N-acetyllactosamines (Galbeta1-4GlcNAc-R) on different mammalian red blood cells, and on nucleated cells originating from a given tissue in various species; (2) goat, sheep, horse and mouse red blood cells lack alpha-Gal epitopes, despite the expression of this epitope on a variety of nucleated cells in these species, including lymphocytes differentiated from the same hematopoietic origin. In this study, flow cytometry and Western blot analyses of pig red blood cells showed that alpha-Gal epitopes on pig red cells developed concomitantly after treatment with neuraminidase, suggesting that the terminal N-acetyllactosaminide glycans were capped with SA-alpha-Gal epitopes. Whereas, the expression of the alpha-Gal epitopes on red blood cells from Sika deer (Cevus nippon hortulorum) were found to be absent even though the epitopes were present on their white blood cells. Thus, these results add new data not only for the terminal carbohydrate structures on cell surface glycans of various mammalian cells, but also for wide variety of epitope expression on the cells from different tissues, which might be useful for understanding their unique states resulting from differentiation and evolution. PMID:20422448

  7. Prostate stromal cell proteomics analysis discriminates normal from tumour reactive stromal phenotypes

    PubMed Central

    Webber, Jason P.; Spary, Lisa K.; Mason, Malcolm D.; Tabi, Zsuzsanna; Brewis, Ian A.; Clayton, Aled

    2016-01-01

    Changes within interstitial stromal compartments often accompany carcinogenesis, and this is true of prostate cancer. Typically, the tissue becomes populated by myofibroblasts that can promote progression. Not all myofibroblasts exhibit the same negative influence, however, and identifying the aggressive form of myofibroblast may provide useful information at diagnosis. A means of molecularly defining such myofibroblasts is unknown. We compared protein profiles of normal and diseased stroma isolated from prostate cancer patients to identify discriminating hallmarks of disease-associated stroma. We included the stimulation of normal stromal cells with known myofibroblast inducers namely soluble TGFβ and exosome-associated-TGFβ and compared the function and protein profiles arising. In all 6-patients examined, diseased stroma exhibited a pro-angiogenic influence on endothelial cells, generating large multicellular vessel-like structures. Identical structures were apparent following stimulation of normal stroma with exosomes (5/6 patients), but TGFβ-stimulation generated a non-angiogenic stroma. Proteomics highlighted disease-related cytoskeleton alterations such as elevated Transgelin (TAGLN). Many of these were also changed following TGFβ or exosome stimulation and did not well discriminate the nature of the stimulus. Soluble TGFβ, however triggered differential expression of proteins related to mitochondrial function including voltage dependent ion channels VDAC1 and 2, and this was not found in the other stromal types studied. Surprisingly, Aldehyde Dehydrogenase (ALDH1A1), a stem-cell associated protein was detected in normal stromal cells and found to decrease in disease. In summary, we have discovered a set of proteins that contribute to defining disease-associated myofibroblasts, and emphasise the similarity between exosome-generated myofibroblasts and those naturally arising in situ. PMID:26934553

  8. Evaluation of the effectiveness of packed red blood cell irradiation by a linear accelerator

    PubMed Central

    Olivo, Ricardo Aparecido; da Silva, Marcus Vinícius; Garcia, Fernanda Bernadelli; Soares, Sheila; Rodrigues Junior, Virmondes; Moraes-Souza, Helio

    2015-01-01

    Irradiation of blood components with ionizing radiation generated by a specific device is recommended to prevent transfusion-associated graft-versus-host disease. However, a linear accelerator can also be used in the absence of such a device, which is the case of the blood bank facility studied herein. In order to evaluate the quality of the irradiated packed red blood cells, this study aimed to determine whether the procedure currently employed in the facility is effective in inhibiting the proliferation of T lymphocytes without damaging blood components. The proliferation of T lymphocytes, plasma potassium levels, and the degree of hemolysis were evaluated and compared to blood bags that received no irradiation. Packed red blood cell bags were irradiated at a dose of 25 Gy in a linear accelerator. For this purpose, a container was designed to hold the bags and to ensure even distribution of irradiation as evaluated by computed tomography and dose-volume histogram. Irradiation was observed to inhibit the proliferation of lymphocytes. The percentage of hemolysis in irradiated bags was slightly higher than in non-irradiated bags (p-value >0.05), but it was always less than 0.4% of the red cell mass. Although potassium increased in both groups, it was more pronounced in irradiated red blood cells, especially after seven days of storage, with a linear increase over storage time. The findings showed that, at an appropriate dosage and under validated conditions, the irradiation of packed red blood cells in a linear accelerator is effective, inhibiting lymphocyte proliferation but without compromising the viability of the red cells. PMID:26041416

  9. Impact of red blood cell transfusion on global and regional measures of oxygenation.

    PubMed

    Roberson, Russell S; Bennett-Guerrero, Elliott

    2012-01-01

    Anemia is common in critically ill patients. Although the goal of transfusion of red blood cells is to increase oxygen-carrying capacity, there are contradictory results about whether red blood cell transfusion to treat moderate anemia (e.g., hemoglobin 7-10 g/dL) improves tissue oxygenation or changes outcomes. Whereas increasing levels of anemia eventually lead to a level of critical oxygen delivery, increased cardiac output and oxygen extraction are homeostatic mechanisms the body uses to prevent a state of dysoxia in the setting of diminished oxygen delivery due to anemia. In order for cardiac output to increase in the face of anemia, normovolemia must be maintained. Transfusion of red blood cells increases blood viscosity, which may actually decrease cardiac output (barring a state of hypovolemia prior to transfusion). Studies have generally shown that transfusion of red blood cells fails to increase oxygen uptake unless oxygen uptake/oxygen delivery dependency exists (e.g., severe anemia or strenuous exercise). Recently, near-infrared spectroscopy, which approximates the hemoglobin saturation of venous blood, has been used to investigate whether transfusion of red blood cells increases tissue oxygenation in regional tissue beds (e.g., brain, peripheral skeletal muscle). These studies have generally shown increases in near-infrared spectroscopy derived measurements of tissue oxygenation following transfusion. Studies evaluating the effect of transfusion on the microcirculation have shown that transfusion increases the functional capillary density. This article will review fundamental aspects of oxygen delivery and extraction, and the effects of red blood cell transfusion on tissue oxygenation as well as the microcirculation. PMID:22238040

  10. Red blood cell and leukocyte alloimmunization in patients awaiting kidney transplantation

    PubMed Central

    da Silva, Silvia Fernandes Ribeiro; Ferreira, Gláucia Maria; da Silva, Sonia Leite; Alves, Tânia Maria de Oliveira; Ribeiro, Ilana Farias; Ribeiro, Thyciana Rodrigues; Cavalcante, Maria do Carmo Serpa

    2013-01-01

    Objective To determine the rates of red blood cell and leukocyte alloimmunization in patients with chronic kidney disease awaiting kidney transplantation. Methods In this cross-sectional and prospective study, the serum of 393 chronic kidney disease patients on a transplant waiting list in Ceará, Northeastern Brazil were tested for red cell and leukocyte antibodies. In addition, demographic, clinical and laboratory data were collected. Results The average age in the sample of 393 patients was 34.1 ± 14 years. Slightly more than half (208; 52.9%) were male. The average numbers of transfusions and gestations were 3.1 ± 3.3 and 1.6 ± 6, respectively. One third (33.6%) were alloimmunized: 78% with leukocyte antibodies, 9.1% with red cell antibodies and 12.9% with both. Red cell antibodies were detected in 29 cases (7.4%), 17 of whom were women, who had received more transfusions than the males (p-value < 0.0001). The most frequently detected red cell antibodies belonged to the Rh (24.1%) and Kell (13.8%) blood group systems. Leukocyte antibodies were detected in 30.5% of cases, 83 of whom were women, who had received more transfusions than the males (p-value < 0.0001) and were more reactive to panel reactive antibodies (p-value < 0.0001). The mean alloreactivity to panel reactive antibodies was 47.7 ± 31.2%. Conclusion Chronic kidney disease patients on the transplant waiting list in Ceará, Brazil, display high rates of red cell (7.4%) and leukocyte (30.5%) alloimmunization. In this sample, alloimmunization was significantly associated with the number of transfusions and gender. PMID:23904808

  11. Regulation of anthocyanin biosynthesis in Arabidopsis thaliana red pap1-D cells metabolically programmed by auxins.

    PubMed

    Liu, Zhong; Shi, Ming-Zhu; Xie, De-Yu

    2014-04-01

    Red pap1-D cells of Arabidopsis thaliana have been cloned from production of anthocyanin pigmentation 1-Dominant (pap1-D) plants. The red cells are metabolically programmed to produce high levels of anthocyanins by a WD40-bHLH-MYB complex that is composed of the TTG1, TT8/GL3 and PAP1 transcription factors. Here, we report that indole 3-acetic acid (IAA), naphthaleneacetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D) regulate anthocyanin biosynthesis in these red cells. Seven concentrations (0, 0.2, 0.4, 2.2, 9, 18 and 27 μM) were tested for the three auxins. IAA and 2,4-D at 2.2-27 μM reduced anthocyanin levels. NAA at 0-0.2 μM or above 9 μM also decreased anthocyanin levels, but from 0.4 to 9 μM, it increased them. HPLC-ESI-MS analysis identified seven cyanin molecules that were produced in red pap1-D cells, and their levels were affected by auxins. The expression levels of ten genes, including six transcription factors (TTG1, EGL3, MYBL2, TT8, GL3 and PAP1) and four pathway genes (PAL1, CHS, DFR and ANS) involved in anthocyanin biosynthesis were analyzed upon various auxin treatments. The resulting data showed that 2,4-D, NAA and IAA control anthocyanin biosynthesis by regulating the expression of TT8, GL3 and PAP1 as well as genes in the anthocyanin biosynthetic pathway, such as DFR and ANS. In addition, the expression of MYBL2, PAL1 and CHS in red pap1-D and wild-type cells differentially respond to the three auxins. Our data demonstrate that the three auxins regulate anthocyanin biosynthesis in metabolically programmed red cells via altering the expression of transcription factor genes and pathway genes. PMID:24370633

  12. Photometric determination of phenomenological correlation between osmotic behavior and hemolysis of red blood cells.

    PubMed

    Yang, X S; Kamino, K

    1995-01-01

    The osmotic behavior of red blood cells from a human and from several other mammalian species was studied by photometric measurements. When red blood cells were suspended in sodium chloride solutions with various osmotic concentrations, the optical density at 620 nm was reciprocally related to the relative volume of the red cells. Thus, we evaluated the osmotic volume changes in the red cells from optical density measurements. The Boyle-van't Hoff relation was applicable to the osmotic behavior of red cells which responded as a complete osmometer in hypertonic and slightly hypotonic (lower than about 240 mOsm) solutions. Also, we examined the rheological correlation between osmotic volume changes and hemolysis. Osmotic hemolysis occurred corresponding to breakdown of the Boyle-van't Hoff relation in hypotonic solutions. The critical osmotic concentration for the breakdown of the Boyle-van't Hoff relation was that for osmotic hemolysis. In Na2SO4 solutions, although the critical osmotic concentration shifted towards a smaller value, the critical volume for the breakdown of the Boyle-van't Hoff relation and for osmotic hemolysis was maintained at a constant value, indicating that the onset of osmotic hemolysis depends exclusively upon the critical volume. In the samples from a human, the critical volume for the onset of hemolysis was estimated to be 1.25 +/- 0.05 in the ratio to the normal volume in iso-osmotic solution. From these obtained results, it is suggested that the red cell behaves in hypotonic solutions as a viscoelastic body of the type represented by the Voigt model, and the viscoelastic breakdown of the membrane results in osmotic hemolysis in hypotonic solution. PMID:8713172

  13. Characterizations of individual human red blood cells from patients with diabetes mellitus (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Lee, SangYun; Jang, Seongsoo; Park, HyunJoo; Park, YongKeun

    2016-03-01

    We systematically measure the morphological, biochemical, and biomechanical properties of individual human red blood cells (RBCs) from patients with diabetes mellitus using quantitative phase imaging technique to characterize the diabetic red cells with respect to those of the healthy. The 3-D refractive index tomograms and 2-D dynamic membrane fluctuation maps of individual RBCs are reconstructed from a set of the retrieved complex optical fields at various laser incidence angles using the Common-path diffraction optical tomography, from which volume, surface area, sphericity, hemoglobin (Hb) concentration, Hb content, and membrane fluctuation are obtained simultaneously. The correlative relations among the retrieved red cell indices of diabetic and healthy RBCs are also investigated with capabilities of individual cell measurement. As expected, there are no significant alterations in morphologies (cellular volumes, surface area, and sphericity) between diabetic and healthy RBCs. However, despite the minute mean corpuscular Hb differences in cell blood count datasheet, the measured Hb concentrations and Hb contents of diabetic RBCs are statistically higher than those of healthy RBCs, which might be related to the glycation of Hb molecules by hyperglycemia. Meanwhile, the membrane fluctuations of diabetic RBCs are clearly diminished compared to healthy red cells, implying the significantly decreased RBC deformability. In particular, it seems that the membrane fluctuations have mild negative relationships with the reported HbA1c levels.

  14. Where does blood go? Prospective observational study of red cell transfusion in north England

    PubMed Central

    Wells, A W; Mounter, P J; Chapman, C E; Stainsby, D; Wallis, J P

    2002-01-01

    Objective To collect population based information on transfusion of red blood cells. Design Prospective observational study over 28 days. Setting Hospital blood banks in the north of England (population 2.9 million). Main outcome measures Indications for transfusion, number of units given, and the age and sex of transfusion recipients. Participants All patients who received a red cell transfusion during the study period. Data completed by hospital blood bank staff. Results The destination of 9848 units was recorded (97% of expected blood use). In total 9774 units were transfused: 5047 (51.6%) units were given to medical patients, 3982 (40.7%) to surgical patients, and 612 (6.3%) to obstetric and gynaecology patients. Nearly half (49.3%) of all blood is given to female recipients, and the mean age of recipients of individual units was 62.7 years. The most common surgical indications for transfusion were total hip replacement (4.6% of all blood transfused) and coronary artery bypass grafting (4.1%). Haematological disorders accounted for 15.5% of use. Overall use was 4274 units per 100 000 population per year. Conclusion In the north east of England more than half of red cell units are transfused for medical indications. Demand for red cell transfusion increases with age. With anticipated changes in the age structure of the population the demand for blood will increase by 4.9% by 2008. What is already known on this topicThere have been no systematic population based surveys on use of red cells in the United KingdomStudies in France and the United States have shown that more than half of transfused red cells go to surgical patientsWhat this study addsIn the north of England over half of red cells are given for medical indicationsRates of red cell transfusion rise steeply with advancing ageSmall increases in the number of elderly people will have large effects on demand PMID:12376439

  15. New diffractometric equations and data processing algorithm for laser ektacytometry of red blood cells

    NASA Astrophysics Data System (ADS)

    Nikitin, S. Yu.; Ustinov, V. D.; Yurchuk, Yu. S.; Lugovtsov, A. E.; Lin, M. D.; Priezzhev, A. V.

    2016-07-01

    The problem of measuring the deformability of red blood cells in shear flow by laser diffractometry (ektacytometry) is considered. New diffractometric equations are obtained, which relate the parameters of the diffraction pattern to the characteristics of the erythrocyte ensemble, such as mean deformability as well as width and asymmetry of the erythrocytes distribution in deformability. A feature of these equations is that they include only geometric parameters of the diffraction pattern but do not contain its energy parameters. Basing on these equations, we propose a new data processing algorithm for the laser ektacytometry of red blood cells.

  16. Bone marrow transplantation for CVID-like humoral immune deficiency associated with red cell aplasia.

    PubMed

    Sayour, Elias J; Mousallem, Talal; Van Mater, David; Wang, Endi; Martin, Paul; Buckley, Rebecca H; Barfield, Raymond C

    2016-10-01

    Patients with common variable immunodeficiency (CVID) have a higher incidence of autoimmune disease, which may mark the disease onset; however, anemia secondary to pure red cell aplasia is an uncommon presenting feature. Here, we describe a case of CVID-like humoral immune deficiency in a child who initially presented with red cell aplasia and ultimately developed progressive bone marrow failure. Although bone marrow transplantation (BMT) has been associated with high mortality in CVID, our patient was successfully treated with a matched sibling BMT and engrafted with >98% donor chimerism and the development of normal antibody titers to diphtheria and tetanus toxoids. PMID:27273469

  17. Simultaneous determination of size and refractive index of red blood cells by light scattering measurements

    SciTech Connect

    Ghosh, N.; Buddhiwant, P.; Uppal, A.; Majumder, S.K.; Patel, H.S.; Gupta, P.K.

    2006-02-20

    We present a fast and accurate approach for simultaneous determination of both the mean diameter and refractive index of a collection of red blood cells (RBCs). The approach uses the peak frequency of the power spectrum and the corresponding phase angle obtained by performing Fourier transform on the measured angular distribution of scattered light to determine these parameters. Results on the measurement of two important clinical parameters, the mean cell volume and mean cell hemoglobin concentration of a collection of RBCs, are presented.

  18. Flow of a circulating tumor cell and red blood cells in microvessels

    NASA Astrophysics Data System (ADS)

    Takeishi, Naoki; Imai, Yohsuke; Yamaguchi, Takami; Ishikawa, Takuji

    2015-12-01

    Quantifying the behavior of circulating tumor cells (CTCs) in the blood stream is of fundamental importance for understanding metastasis. Here, we investigate the flow mode and velocity of CTCs interacting with red blood cells (RBCs) in various sized microvessels. The flow of leukocytes in microvessels has been described previously; a leukocyte forms a train with RBCs in small microvessels and exhibits margination in large microvessels. Important differences in the physical properties of leukocytes and CTCs result from size. The dimensions of leukocytes are similar to those of RBCs, but CTCs are significantly larger. We investigate numerically the size effects on the flow mode and the cell velocity, and we identify similarities and differences between leukocytes and CTCs. We find that a transition from train formation to margination occurs when (R -a ) /tR≈1 , where R is the vessel radius, a is the cell radius, and tR is the thickness of RBCs, but that the motion of RBCs differs from the case of leukocytes. Our results also show that the velocities of CTCs and leukocytes are larger than the average blood velocity, but only CTCs move faster than RBCs for microvessels of R /a ≈1.5 -2.0 . These findings are expected to be useful not only for understanding metastasis, but also for developing microfluidic devices.

  19. A micro-scale simulation of red blood cell passage through symmetric and asymmetric bifurcated vessels.

    PubMed

    Wang, Tong; Rongin, Uwitije; Xing, Zhongwen

    2016-01-01

    Blood exhibits a heterogeneous nature of hematocrit, velocity, and effective viscosity in microcapillaries. Microvascular bifurcations have a significant influence on the distribution of the blood cells and blood flow behavior. This paper presents a simulation study performed on the two-dimensional motions and deformation of multiple red blood cells in microvessels with diverging and converging bifurcations. Fluid dynamics and membrane mechanics were incorporated. Effects of cell shape, hematocrit, and deformability of the cell membrane on rheological behavior of the red blood cells and the hemodynamics have been investigated. It was shown that the blood entering the daughter branch with a higher flow rate tended to receive disproportionally more cells. The results also demonstrate that red blood cells in microvessels experienced lateral migration in the parent channel and blunted velocity profiles in both straight section and daughter branches, and this effect was influenced by the shape and the initial position of the cells, the hematocrit, and the membrane deformability. In addition, a cell free region around the tip of the confluence was observed. The simulation results are qualitatively consistent with existing experimental findings. This study may provide fundamental knowledge for a better understanding of hemodynamic behavior of micro-scale blood flow. PMID:26830454

  20. A micro-scale simulation of red blood cell passage through symmetric and asymmetric bifurcated vessels

    PubMed Central

    Wang, Tong; Rongin, Uwitije; Xing, Zhongwen

    2016-01-01

    Blood exhibits a heterogeneous nature of hematocrit, velocity, and effective viscosity in microcapillaries. Microvascular bifurcations have a significant influence on the distribution of the blood cells and blood flow behavior. This paper presents a simulation study performed on the two-dimensional motions and deformation of multiple red blood cells in microvessels with diverging and converging bifurcations. Fluid dynamics and membrane mechanics were incorporated. Effects of cell shape, hematocrit, and deformability of the cell membrane on rheological behavior of the red blood cells and the hemodynamics have been investigated. It was shown that the blood entering the daughter branch with a higher flow rate tended to receive disproportionally more cells. The results also demonstrate that red blood cells in microvessels experienced lateral migration in the parent channel and blunted velocity profiles in both straight section and daughter branches, and this effect was influenced by the shape and the initial position of the cells, the hematocrit, and the membrane deformability. In addition, a cell free region around the tip of the confluence was observed. The simulation results are qualitatively consistent with existing experimental findings. This study may provide fundamental knowledge for a better understanding of hemodynamic behavior of micro-scale blood flow. PMID:26830454

  1. A micro-scale simulation of red blood cell passage through symmetric and asymmetric bifurcated vessels

    NASA Astrophysics Data System (ADS)

    Wang, Tong; Rongin, Uwitije; Xing, Zhongwen

    2016-02-01

    Blood exhibits a heterogeneous nature of hematocrit, velocity, and effective viscosity in microcapillaries. Microvascular bifurcations have a significant influence on the distribution of the blood cells and blood flow behavior. This paper presents a simulation study performed on the two-dimensional motions and deformation of multiple red blood cells in microvessels with diverging and converging bifurcations. Fluid dynamics and membrane mechanics were incorporated. Effects of cell shape, hematocrit, and deformability of the cell membrane on rheological behavior of the red blood cells and the hemodynamics have been investigated. It was shown that the blood entering the daughter branch with a higher flow rate tended to receive disproportionally more cells. The results also demonstrate that red blood cells in microvessels experienced lateral migration in the parent channel and blunted velocity profiles in both straight section and daughter branches, and this effect was influenced by the shape and the initial position of the cells, the hematocrit, and the membrane deformability. In addition, a cell free region around the tip of the confluence was observed. The simulation results are qualitatively consistent with existing experimental findings. This study may provide fundamental knowledge for a better understanding of hemodynamic behavior of micro-scale blood flow.

  2. Investigating the fluid mechanics behind red blood cell-induced lateral platelet motion

    NASA Astrophysics Data System (ADS)

    Crowl Erickson, Lindsay; Fogelson, Aaron

    2009-11-01

    Platelets play an essential role in blood clotting; they adhere to damaged tissue and release chemicals that activate other platelets. Yet in order to adhere, platelets must first come into contact with the injured vessel wall. Under arterial flow conditions, platelets have an enhanced concentration near blood vessel walls. This non-uniform cell distribution depends on the fluid dynamics of blood as a heterogeneous medium. We use a parallelized lattice Boltzmann-immersed boundary method to solve the flow dynamics of red cells and platelets in a periodic 2D vessel with no-slip boundary conditions. Red cells are treated as biconcave immersed boundary objects with isotropic Skalak membrane tension and an internal viscosity five times that of the surrounding plasma. Using this method we analyze the influence of shear rate, hematocrit, and red cell membrane properties on lateral platelet motion. We find that the effective diffusion of platelets is significantly lower near the vessel wall compared to the center of the vessel. Insight gained from this work could lead to significant improvements to current models for platelet adhesion where the presence of red blood cells is neglected due to computational intensity.

  3. The exported Plasmodium berghei protein IBIS1 delineates membranous structures in infected red blood cells

    PubMed Central

    Ingmundson, Alyssa; Nahar, Carolin; Brinkmann, Volker; Lehmann, Maik J; Matuschewski, Kai

    2012-01-01

    Summary The importance of pathogen-induced host cell remodelling has been well established for red blood cell infection by the human malaria parasite Plasmodium falciparum. Exported parasite-encoded proteins, which often possess a signature motif, termed Plasmodium export element (PEXEL) or host-targeting (HT) signal, are critical for the extensive red blood cell modifications. To what extent remodelling of erythrocyte membranes also occurs in non-primate hosts and whether it is in fact a hallmark of all mammalian Plasmodium parasites remains elusive. Here we characterize a novel Plasmodium berghei PEXEL/HT-containing protein, which we term IBIS1. Temporal expression and spatial localization determined by fluorescent tagging revealed the presence of IBIS1 at the parasite/host interface during both liver and blood stages of infection. Targeted deletion of the IBIS1 protein revealed a mild impairment of intra-erythrocytic growth indicating a role for these structures in the rapid expansion of the parasite population in the blood in vivo. In red blood cells, the protein localizes to dynamic, punctate structures external to the parasite. Biochemical and microscopic data revealed that these intra-erythrocytic P. berghei-induced structures (IBIS) are membranous indicating that P. berghei, like P. falciparum, creates an intracellular membranous network in infected red blood cells. PMID:22329949

  4. Numerical simulation of rheology of red blood cell rouleaux in microchannels

    NASA Astrophysics Data System (ADS)

    Wang, T.; Pan, T.-W.; Xing, Z. W.; Glowinski, R.

    2009-04-01

    An elastic spring model is applied to simulate the skeletal structure of the red blood cell (RBC) membrane and to study the dynamical behaviors of the red blood cell rouleaux (aggregates) in microchannels. The biconcave shape of RBCs in static plasma and the tank-treading phenomenon of single RBCs in simple shear flows have been successfully captured using this model. The aggregation and dissociation of RBCs with different deformability have been investigated in both shear and Poiseuille flows by taking into consideration the rheology of the cells and the intercellular interaction kinetics. It is found that the equilibrium configuration of the rouleaux formed under no-flow condition, the motion of the rouleaux in the flows, and the rheological behavior of individual cells in the rouleaux is closely related to the intercellular interaction strength, hydrodynamic viscous forces, and the deformability of the cell membrane.

  5. Numerical simulation of rheology of red blood cell rouleaux in microchannels.

    PubMed

    Wang, T; Pan, T-W; Xing, Z W; Glowinski, R

    2009-04-01

    An elastic spring model is applied to simulate the skeletal structure of the red blood cell (RBC) membrane and to study the dynamical behaviors of the red blood cell rouleaux (aggregates) in microchannels. The biconcave shape of RBCs in static plasma and the tank-treading phenomenon of single RBCs in simple shear flows have been successfully captured using this model. The aggregation and dissociation of RBCs with different deformability have been investigated in both shear and Poiseuille flows by taking into consideration the rheology of the cells and the intercellular interaction kinetics. It is found that the equilibrium configuration of the rouleaux formed under no-flow condition, the motion of the rouleaux in the flows, and the rheological behavior of individual cells in the rouleaux is closely related to the intercellular interaction strength, hydrodynamic viscous forces, and the deformability of the cell membrane. PMID:19518265

  6. Red Raspberry Phenols Inhibit Angiogenesis: A Morphological and Subcellular Analysis Upon Human Endothelial Cells.

    PubMed

    Sousa, M; Machado, V; Costa, R; Figueira, M E; Sepodes, B; Barata, P; Ribeiro, L; Soares, R

    2016-07-01

    Polyphenols are a class of natural compounds whose potential as antioxidant, anti-inflammatory, and anti-angiogenesis has been reported in many pathological conditions. Red raspberry extract, rich in polyphenols, has been reported to exert anti-inflammatory effects and prevent cell proliferation in distinct animal models. However, the signaling pathways involved remain unknown. Herein, we used human microvascular endothelial cells (HMVECs) to determine the influence of red raspberry phenolic compound extract concentrations, ranging from 10 to 250 µg gallic acid equivalents (GAE)/mL, on endothelium viability (MTS assay), proliferation (BrdU incorporation), migration (injury assay), and capillary-like structures formation (Matrigel assay). Protein expression in cell lysates was determined by Western blot analysis. We showed that red raspberry extracts reduced cell viability (GI50  = 87,64 ± 6,59 μg GAE/mL) and proliferation in a dose-dependent manner. A significant abrogation of cells ability to migrate to injured areas, even at low concentrations, was observed by injury assay. Cell assembly into capillary-like structures on Matrigel also decreased in a dose dependent-manner for higher extract concentrations, as well as the number of branching points per unit of area. Protein expression analysis showed a dose-dependent decrease in Phospho-VEGFR2 expression, implying abrogation of VEGF signaling activity. We also showed for the first time that red raspberry phenolic compounds induce the rearrangement of filamentous actin cytoskeleton, with an isotropy increase found for higher testing concentrations. Taken together, our findings corroborate the anti-angiogenic potential of red raspberry phenolic compounds and provide new insights into their mode of action upon endothelium. J. Cell. Biochem. 117: 1604-1612, 2016. © 2015 Wiley Periodicals, Inc. PMID:26590362

  7. Synthesis and assembly of membrane skeletal proteins in mammalian red cell precursors

    SciTech Connect

    Hanspal, M.; Palek, J.

    1987-09-01

    The synthesis of membrane skeletal proteins in avian nucleated red cells has been the subject of extensive investigation, whereas little is known about skeletal protein synthesis in bone marrow erythroblasts and peripheral blood reticulocytes in mammals. To address this question, we have isolated nucleated red cell precursors and reticulocytes from spleens and from the peripheral blood, respectively, of rats with phenylhydrazine-induced hemolytic anemia and pulse-labeled them with (/sup 35/S)methionine. Pulse-labeling of nucleated red cell precursors shows that the newly synthesized alpha- and beta-spectrins are present in the cytosol, with a severalfold excess of alpha-spectrin over beta-spectrin. However, in the membrane-skeletal fraction, newly synthesized alpha- and beta-spectrins are assembled in stoichiometric amounts, suggesting that the association of alpha-spectrin with the membrane skeleton may- be rate-limited by the amount of beta-spectrin synthesized, as has been shown recently in avian erythroid cells. Pulse-chase experiments in the rat nucleated red cell precursors show that the newly synthesized alpha- and beta-spectrin of the cytosol turn over coordinately and extremely rapidly. In contrast, in the membrane-skeletal fraction, the newly synthesized polypeptides of spectrin are stable. In contrast to nucleated erythroid cells, in reticulocytes the synthesis of alpha- and beta-spectrins is markedly diminished compared with the synthesis and assembly of proteins comigrating with bands 2.1 and 4.1 on SDS gels. Thus, in nucleated red cell precursors, the newly synthesized spectrin may be attached to the plasma membrane before proteins 2.1 and 4.1 are completely synthesized and incorporated in the membrane.

  8. A Lattice Boltzmann Fictitious Domain Method for Modeling Red Blood Cell Deformation and Multiple-Cell Hydrodynamic Interactions in Flow

    SciTech Connect

    Shi, Xing; Lin, Guang; Zou, Jianfeng; Fedosov, Dmitry A.

    2013-07-20

    To model red blood cell (RBC) deformation in flow, the recently developed LBM-DLM/FD method ([Shi and Lim, 2007)29], derived from the lattice Boltzmann method and the distributed Lagrange multiplier/fictitious domain methodthe fictitious domain method, is extended to employ the mesoscopic network model for simulations of red blood cell deformation. The flow is simulated by the lattice Boltzmann method with an external force, while the network model is used for modeling red blood cell deformation and the fluid-RBC interaction is enforced by the Lagrange multiplier. To validate parameters of the RBC network model, sThe stretching numerical tests on both coarse and fine meshes are performed and compared with the corresponding experimental data to validate the parameters of the RBC network model. In addition, RBC deformation in pipe flow and in shear flow is simulated, revealing the capacity of the current method for modeling RBC deformation in various flows.

  9. Heme oxygenase-1 deficiency alters erythroblastic island formation, steady-state erythropoiesis and red blood cell lifespan in mice

    PubMed Central

    Fraser, Stuart T.; Midwinter, Robyn G.; Coupland, Lucy A.; Kong, Stephanie; Berger, Birgit S.; Yeo, Jia Hao; Andrade, Osvaldo Cooley; Cromer, Deborah; Suarna, Cacang; Lam, Magda; Maghzal, Ghassan J.; Chong, Beng H.; Parish, Christopher R.; Stocker, Roland

    2015-01-01

    Heme oxygenase-1 is critical for iron recycling during red blood cell turnover, whereas its impact on steady-state erythropoiesis and red blood cell lifespan is not known. We show here that in 8- to 14-week old mice, heme oxygenase-1 deficiency adversely affects steady-state erythropoiesis in the bone marrow. This is manifested by a decrease in Ter-119+-erythroid cells, abnormal adhesion molecule expression on macrophages and erythroid cells, and a greatly diminished ability to form erythroblastic islands. Compared with wild-type animals, red blood cell size and hemoglobin content are decreased, while the number of circulating red blood cells is increased in heme oxygenase-1 deficient mice, overall leading to microcytic anemia. Heme oxygenase-1 deficiency increases oxidative stress in circulating red blood cells and greatly decreases the frequency of macrophages expressing the phosphatidylserine receptor Tim4 in bone marrow, spleen and liver. Heme oxygenase-1 deficiency increases spleen weight and Ter119+-erythroid cells in the spleen, although α4β1-integrin expression by these cells and splenic macrophages positive for vascular cell adhesion molecule 1 are both decreased. Red blood cell lifespan is prolonged in heme oxygenase-1 deficient mice compared with wild-type mice. Our findings suggest that while macrophages and relevant receptors required for red blood cell formation and removal are substantially depleted in heme oxygenase-1 deficient mice, the extent of anemia in these mice may be ameliorated by the prolonged lifespan of their oxidatively stressed erythrocytes. PMID:25682599

  10. Dynamic quantitative microscopy and nanoscopy of red blood cells in sickle cell disease

    NASA Astrophysics Data System (ADS)

    Shaked, Natan T.; Satterwhite, Lisa L.; Telen, Marilyn J.; Truskey, George A.; Wax, Adam

    2012-03-01

    We have applied wide-field digital interferometric techniques to quantitatively image sickle red blood cells (RBCs) [1] in a noncontact label-free manner, and measure the nanometer-scale fluctuations in their thickness as an indication of their stiffness. The technique can simultaneously measure the fluctuations for multiple spatial points on the RBC and thus yields a map describing the stiffness of each RBC in the field of view. Using this map, the local rigidity regions of the RBC are evaluated quantitatively. Since wide-field digital interferometry is a quantitative holographic imaging technique rather than one-point measurement, it can be used to simultaneously evaluate cell transverse morphology plus thickness in addition to its stiffness profile. Using this technique, we examine the morphology and dynamics of RBCs from individuals who suffer from sickle cell disease, and find that the sickle RBCs are significantly stiffer than healthy RBCs. Furthermore, we show that the technique is sensitive enough to distinguish various classes of sickle RBCs, including sickle RBCs with visibly-normal morphology, compared to the stiffer crescent-shaped sickle RBCs.

  11. Effects of iron supplementation on red blood cell hemoglobin content in pregnancy

    PubMed Central

    Schoorl, Margreet; Schoorl, Marianne; van der Gaag, Derek; Bartels, Piet C. M.

    2012-01-01

    Although a mild degree of anemia is common in the third trimester of pregnancy, it remains a challenge to establish whether a decrease in hemoglobin (Hb) concentration is physiological or pathological. The World Health Organization suggested a Hb concentration of 110 g/L to discriminate anemia. Several European investigators recommended Hb cut-off values of between 101–110 g/L. The aim of this study was to establish short-term effects of iron supplementation on the hemoglobin content of reticulocytes (Ret-He) and red blood cells (RBC-He) in case of suspected iron deficient erythropoiesis (IDE) in the third trimester of pregnancy. Twenty-five subjects with suspected IDE during pregnancy (Hb ≤110g/L, Ret-He <29.6 pg, zinc protoporphyrin >75 mol/mol hem) participated in the study. After iron supplementation, reticulocyte counts increased from 0.061±0.015×1012/L to 0.079±0.026×1012/L and Ret-He increased from 23.6±2.8 pg to 28.3±2.6 pg (P=<0.001). RBC-He increased from 26.9±1.9 pg to 27.4±1.8 pg (not significant, NS) and Ret-He/RBC-He ratio increased from 0.97±0.06 towards 1.07±0.05 (P=<0.001). Hb concentrations demonstrated an obvious increase from 105±6 g/L towards 115±5 g/L (P≤0.001) after supplementation. An obvious increase in RBC distribution width was observed from 45.0±3.6 fL towards 52.3±7.0 fL (P≤0.001). We recommend that Ret-He and Ret-He/RBC-He ratio be integrated into the protocols for anemia screening and for monitoring effects of iron supplementation during pregnancy. In particular, the parameters should be considered in subjects with Hb results in the controversial range of 101–108 g/L. PMID:23355942

  12. Autologous Doping with Cryopreserved Red Blood Cells - Effects on Physical Performance and Detection by Multivariate Statistics.

    PubMed

    Malm, Christer B; Khoo, Nelson S; Granlund, Irene; Lindstedt, Emilia; Hult, Andreas

    2016-01-01

    The discovery of erythropoietin (EPO) simplified blood doping in sports, but improved detection methods, for EPO has forced cheating athletes to return to blood transfusion. Autologous blood transfusion with cryopreserved red blood cells (RBCs) is the method of choice, because no valid method exists to accurately detect such event. In endurance sports, it can be estimated that elite athletes improve performance by up to 3% with blood doping, regardless of method. Valid detection methods for autologous blood doping is important to maintain credibility of athletic performances. Recreational male (N = 27) and female (N = 11) athletes served as Transfusion (N = 28) and Control (N = 10) subjects in two different transfusion settings. Hematological variables and physical performance were measured before donation of 450 or 900 mL whole blood, and until four weeks after re-infusion of the cryopreserved RBC fraction. Blood was analyzed for transferrin, iron, Hb, EVF, MCV, MCHC, reticulocytes, leucocytes and EPO. Repeated measures multivariate analysis of variance (MANOVA) and pattern recognition using Principal Component Analysis (PCA) and Orthogonal Projections of Latent Structures (OPLS) discriminant analysis (DA) investigated differences between Control and Transfusion groups over time. Significant increase in performance (15 ± 8%) and VO2max (17 ± 10%) (mean ± SD) could be measured 48 h after RBC re-infusion, and remained increased for up to four weeks in some subjects. In total, 533 blood samples were included in the study (Clean = 220, Transfused = 313). In response to blood transfusion, the largest change in hematological variables occurred 48 h after blood donation, when Control and Transfused groups could be separated with OPLS-DA (R2 = 0.76/Q2 = 0.59). RBC re-infusion resulted in the best model (R2 = 0.40/Q2 = 0.10) at the first sampling point (48 h), predicting one false positive and one false negative. Over all, a 25% and 86% false positives ratio was

  13. SiR–Hoechst is a far-red DNA stain for live-cell nanoscopy

    PubMed Central

    Lukinavičius, Gražvydas; Blaukopf, Claudia; Pershagen, Elias; Schena, Alberto; Reymond, Luc; Derivery, Emmanuel; Gonzalez-Gaitan, Marcos; D'Este, Elisa; Hell, Stefan W.; Wolfram Gerlich, Daniel; Johnsson, Kai

    2015-01-01

    Cell-permeable DNA stains are popular markers in live-cell imaging. Currently used DNA stains for live-cell imaging are either toxic, require illumination with blue light or are not compatible with super-resolution microscopy, thereby limiting their utility. Here we describe a far-red DNA stain, SiR–Hoechst, which displays minimal toxicity, is applicable in different cell types and tissues, and is compatible with super-resolution microscopy. The combination of these properties makes this probe a powerful tool for live-cell imaging. PMID:26423723

  14. SiR-Hoechst is a far-red DNA stain for live-cell nanoscopy.

    PubMed

    Lukinavičius, Gražvydas; Blaukopf, Claudia; Pershagen, Elias; Schena, Alberto; Reymond, Luc; Derivery, Emmanuel; Gonzalez-Gaitan, Marcos; D'Este, Elisa; Hell, Stefan W; Gerlich, Daniel Wolfram; Johnsson, Kai

    2015-01-01

    Cell-permeable DNA stains are popular markers in live-cell imaging. Currently used DNA stains for live-cell imaging are either toxic, require illumination with blue light or are not compatible with super-resolution microscopy, thereby limiting their utility. Here we describe a far-red DNA stain, SiR-Hoechst, which displays minimal toxicity, is applicable in different cell types and tissues, and is compatible with super-resolution microscopy. The combination of these properties makes this probe a powerful tool for live-cell imaging. PMID:26423723

  15. Unfair discrimination in prenatal aneuploidy screening using cell-free DNA?

    PubMed

    Rolfes, Vasilija; Schmitz, Dagmar

    2016-03-01

    Non-invasive prenatal testing on the basis of cell-free DNA of placental origin (NIPT) changed the landscape of prenatal care and is seen as superior to all other up to now implemented prenatal screening procedures - at least in the high-risk population. NIPT has spread almost worldwide commercially, but only in a few countries the costs of NIPT are covered by insurance companies. Such financial barriers in prenatal testing can lead to significant restrictions to the average range of opportunities of pregnant women and couples, which on an intersubjective level can be defined as unfair discrimination and on an individual level weakens reproductive autonomy. Given that enabling reproductive autonomy is the main ethical justification for offering prenatal (genetic) testing, these barriers are not only an issue of justice in health care, but are potentially counteracting the primary purpose of these testing procedures. PMID:26773245

  16. NMDA Receptors Multiplicatively Scale Visual Signals and Enhance Directional Motion Discrimination in Retinal Ganglion Cells.

    PubMed

    Poleg-Polsky, Alon; Diamond, Jeffrey S

    2016-03-16

    Postsynaptic responses in many CNS neurons are typically small and variable, often making it difficult to distinguish physiologically relevant signals from background noise. To extract salient information, neurons are thought to integrate multiple synaptic inputs and/or selectively amplify specific synaptic activation patterns. Here, we present evidence for a third strategy: directionally selective ganglion cells (DSGCs) in the mouse retina multiplicatively scale visual signals via a mechanism that requires both nonlinear NMDA receptor (NMDAR) conductances in DSGC dendrites and directionally tuned inhibition provided by the upstream retinal circuitry. Postsynaptic multiplication enables DSGCs to discriminate visual motion more accurately in noisy visual conditions without compromising directional tuning. These findings demonstrate a novel role for NMDARs in synaptic processing and provide new insights into how synaptic and network features interact to accomplish physiologically relevant neural computations. PMID:26948896

  17. Toxicogenomics-based discrimination of toxic mechanism in HepG2 human hepatoma cells.

    PubMed

    Burczynski, M E; McMillian, M; Ciervo, J; Li, L; Parker, J B; Dunn, R T; Hicken, S; Farr, S; Johnson, M D

    2000-12-01

    The rapid discovery of sequence information from the Human Genome Project has exponentially increased the amount of data that can be retrieved from biomedical experiments. Gene expression profiling, through the use of microarray technology, is rapidly contributing to an improved understanding of global, coordinated cellular events in a variety of paradigms. In the field of toxicology, the potential application of toxicogenomics to indicate the toxicity of unknown compounds has been suggested but remains largely unsubstantiated to date. A major supposition of toxicogenomics is that global changes in the expression of individual mRNAs (i.e., the transcriptional responses of cells to toxicants) will be sufficiently distinct, robust, and reproducible to allow discrimination of toxicants from different classes. Definitive demonstration is still lacking for such specific "genetic fingerprints," as opposed to nonspecific general stress responses that may be indistinguishable between compounds and therefore not suitable as probes of toxic mechanisms. The present studies demonstrate a general application of toxicogenomics that distinguishes two mechanistically unrelated classes of toxicants (cytotoxic anti-inflammatory drugs and DNA-damaging agents) based solely upon a cluster-type analysis of genes differentially induced or repressed in cultured cells during exposure to these compounds. Initial comparisons of the expression patterns for 100 toxic compounds, using all approximately 250 genes on a DNA microarray ( approximately 2.5 million data points), failed to discriminate between toxicant classes. A major obstacle encountered in these studies was the lack of reproducible gene responses, presumably due to biological variability and technological limitations. Thus multiple replicate observations for the prototypical DNA damaging agent, cisplatin, and the non-steroidal anti-inflammatory drugs (NSAIDs) diflunisal and flufenamic acid were made, and a subset of genes yielding

  18. Directly observed reversible shape changes and hemoglobin stratification during centrifugation of human and Amphiuma red blood cells.

    PubMed

    Hoffman, Joseph F; Inoué, Shinya

    2006-02-21

    This paper describes changes that occur in human and Amphiuma red blood cells observed during centrifugation with a special microscope. Dilute suspensions of cells were layered, in a centrifuge chamber, above an osmotically matched dense solution, containing Nycodenz, Ficoll, or Percoll (Pharmacia) that formed a density gradient that allowed the cells to slowly settle to an equilibrium position. Biconcave human red blood cells moved downward at low forces with minimum wobble. The cells oriented vertically when the force field was increased and Hb sedimented as the lower part of each cell became bulged and assumed a "bag-like" shape. The upper centripetal portion of the cell became thinner and remained biconcave. These changes occurred rapidly and were completely reversible upon lowering the centrifugal force. Bag-shaped cells, upon touching red cells in rouleau, immediately reverted to biconcave disks as they flipped onto a stack. Amphiuma red cells displayed a different type of reversible stratification and deformation at high force fields. Here the cells became stretched, with the nucleus now moving centrifugally, the Hb moving centripetally, and the bottom of the cells becoming thinner and clear. Nevertheless, the distribution of the marginal bands at the cells' rim was unchanged. We conclude that centrifugation, per se, while changing a red cell's shape and the distribution of its intracellular constituents, does so in a completely reversible manner. Centrifugation of red cells harboring altered or missing structural elements could provide information on shape determinants that are still unexplained. PMID:16477016

  19. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells.

    PubMed

    Canuto, K S; Sergio, L P S; Guimarães, O R; Geller, M; Paoli, F; Fonseca, A S

    2015-10-01

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia colicells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficientE. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. PMID:26445338

  20. Low-level red laser therapy alters effects of ultraviolet C radiation on Escherichia coli cells

    PubMed Central

    Canuto, K.S.; Sergio, L.P.S.; Guimarães, O.R.; Geller, M.; Paoli, F.; Fonseca, A.S.

    2015-01-01

    Low-level lasers are used at low power densities and doses according to clinical protocols supplied with laser devices or based on professional practice. Although use of these lasers is increasing in many countries, the molecular mechanisms involved in effects of low-level lasers, mainly on DNA, are controversial. In this study, we evaluated the effects of low-level red lasers on survival, filamentation, and morphology of Escherichia colicells that were exposed to ultraviolet C (UVC) radiation. Exponential and stationary wild-type and uvrA-deficientE. coli cells were exposed to a low-level red laser and in sequence to UVC radiation. Bacterial survival was evaluated to determine the laser protection factor (ratio between the number of viable cells after exposure to the red laser and UVC and the number of viable cells after exposure to UVC). Bacterial filaments were counted to obtain the percentage of filamentation. Area-perimeter ratios were calculated for evaluation of cellular morphology. Experiments were carried out in duplicate and the results are reported as the means of three independent assays. Pre-exposure to a red laser protected wild-type and uvrA-deficient E. coli cells against the lethal effect of UVC radiation, and increased the percentage of filamentation and the area-perimeter ratio, depending on UVC fluence and physiological conditions in the cells. Therapeutic, low-level red laser radiation can induce DNA lesions at a sub-lethal level. Consequences to cells and tissues should be considered when clinical protocols based on this laser are carried out. PMID:26445338

  1. Monomeric Garnet, a far-red fluorescent protein for live-cell STED imaging

    PubMed Central

    Hense, Anika; Prunsche, Benedikt; Gao, Peng; Ishitsuka, Yuji; Nienhaus, Karin; Ulrich Nienhaus, G.

    2015-01-01

    The advancement of far-red emitting variants of the green fluorescent protein (GFP) is crucially important for imaging live cells, tissues and organisms. Despite notable efforts, far-red marker proteins still need further optimization to match the performance of their green counterparts. Here we present mGarnet, a robust monomeric marker protein with far-red fluorescence peaking at 670 nm. Thanks to its large extinction coefficient of 95,000 M−1cm−1, mGarnet can be efficiently excited with 640-nm light on the red edge of its 598-nm excitation band. A large Stokes shift allows essentially the entire fluorescence emission to be collected even with 640-nm excitation, counterbalancing the lower fluorescence quantum yield of mGarnet, 9.1%, that is typical of far-red FPs. We demonstrate an excellent performance as a live-cell fusion marker in STED microscopy, using 640 nm excitation and 780 nm depletion wavelengths. PMID:26648024

  2. Red emission fluorescent probes for visualization of monoamine oxidase in living cells.

    PubMed

    Li, Ling-Ling; Li, Kun; Liu, Yan-Hong; Xu, Hao-Ran; Yu, Xiao-Qi

    2016-01-01

    Here we report two novel red emission fluorescent probes for the highly sensitive and selective detection of monoamine oxidase (MAO) with large Stokes shift (227 nm). Both of the probes possess solid state fluorescence and can accomplish the identification of MAO on test papers. The probe MAO-Red-1 exhibited a detection limit down to 1.2 μg mL(-1) towards MAO-B. Moreover, the cleavage product was unequivocally conformedby HPLC and LCMS and the result was in accordance with the proposed oxidative deamination mechanism. The excellent photostability of MAO-Red-1 was proved both in vitro and in vivo through fluorescent kinetic experiment and laser exposure experiment of confocal microscopy, respectively. Intracellular experiments also confirmed the low cytotoxity and exceptional cell imaging abilities of MAO-Red-1. It was validated both in HeLa and HepG2 cells that MAO-Red-1 was capable of reporting MAO activity through the variation of fluorescence intensity. PMID:27499031

  3. Monomeric Garnet, a far-red fluorescent protein for live-cell STED imaging.

    PubMed

    Hense, Anika; Prunsche, Benedikt; Gao, Peng; Ishitsuka, Yuji; Nienhaus, Karin; Nienhaus, G Ulrich

    2015-01-01

    The advancement of far-red emitting variants of the green fluorescent protein (GFP) is crucially important for imaging live cells, tissues and organisms. Despite notable efforts, far-red marker proteins still need further optimization to match the performance of their green counterparts. Here we present mGarnet, a robust monomeric marker protein with far-red fluorescence peaking at 670 nm. Thanks to its large extinction coefficient of 95,000 M(-1)cm(-1), mGarnet can be efficiently excited with 640-nm light on the red edge of its 598-nm excitation band. A large Stokes shift allows essentially the entire fluorescence emission to be collected even with 640-nm excitation, counterbalancing the lower fluorescence quantum yield of mGarnet, 9.1%, that is typical of far-red FPs. We demonstrate an excellent performance as a live-cell fusion marker in STED microscopy, using 640 nm excitation and 780 nm depletion wavelengths. PMID:26648024

  4. Red emission fluorescent probes for visualization of monoamine oxidase in living cells

    PubMed Central

    Li, Ling-Ling; Li, Kun; Liu, Yan-Hong; Xu, Hao-Ran; Yu, Xiao-Qi

    2016-01-01

    Here we report two novel red emission fluorescent probes for the highly sensitive and selective detection of monoamine oxidase (MAO) with large Stokes shift (227 nm). Both of the probes possess solid state fluorescence and can accomplish the identification of MAO on test papers. The probe MAO-Red-1 exhibited a detection limit down to 1.2 μg mL−1 towards MAO-B. Moreover, the cleavage product was unequivocally conformedby HPLC and LCMS and the result was in accordance with the proposed oxidative deamination mechanism. The excellent photostability of MAO-Red-1 was proved both in vitro and in vivo through fluorescent kinetic experiment and laser exposure experiment of confocal microscopy, respectively. Intracellular experiments also confirmed the low cytotoxity and exceptional cell imaging abilities of MAO-Red-1. It was validated both in HeLa and HepG2 cells that MAO-Red-1 was capable of reporting MAO activity through the variation of fluorescence intensity. PMID:27499031

  5. Gallbladder visualization during technetium-99m-labeled red cell scintigraphy for gastrointestinal bleeding

    SciTech Connect

    Brill, D.R.

    1985-12-01

    Localization of radionuclide activity in the gallbladder was seen on delayed views following injection of 99mTc-labeled red blood cells for gastrointestinal bleeding in five patients. The mechanism for this unusual finding probably relates to labeling of heme, the biochemical precursor of bilirubin. All patients had had prior transfusions. All but one had severe renal impairment, probably an important predisposing factor.

  6. Red blood cell fatty acid composition and the metabolic syndrome: NHLBI GOLDN study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Different fatty acids may vary in their effect on the metabolic syndrome (MetS). We tested whether fatty acid classes measured in red blood cells (RBC) are associated with the MetS or its components. Included were men (n=497, 49+/-16 y) and women (n=539, 48+/-16 y) from 187 families in the Genetics ...

  7. Celiac disease with pure red cell aplasia: an unusual hematologic association in pediatric age group.

    PubMed

    Chatterjee, Sitangshu; Dey, Pranab Kumar; Roy, Pratyay; Sinha, Malay Kumar

    2014-09-01

    Anemia in Celiac disease (CD) is usually hypoproliferative, reflecting impaired absorption of essential nutrients like iron and various vitamins. We report a 2-year-old boy with Celiac disease and severe anemia due to pure red cell aplasia, diagnosed by bone marrow biopsy. This rare, unexplained extra digestive manifestation responded to gluten free diet. PMID:25332626

  8. A Cell Culture Derived from the Red Flour Beetle, Tribolium castaneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The red flour beetle, Tribolium castaneum, has become a model organism for agricultural and medical research (e.g., Li et al., 2010). We are in the process of establishing a continuously replicating T. castaneum cell line. Coupled with the recently completed genome sequence (Richards et al., 2008, ...

  9. Survival of Er(a+) red cells in a patient with allo-anti-Era

    SciTech Connect

    Thompson, H.W.; Skradski, K.J.; Thoreson, J.R.; Polesky, H.F.

    1985-03-01

    /sup 51/Chromium-labeled Er(a+) red cells survived nearly normally (T1/2 of 21 days) in a patient with allo-anti-Era. Transfusion of Er(a+) blood was without significant reaction and did not affect the anti-Era titer.

  10. Automatic tracking of red blood cells in micro channels using OpenCV

    NASA Astrophysics Data System (ADS)

    Rodrigues, Vânia; Rodrigues, Pedro J.; Pereira, Ana I.; Lima, Rui

    2013-10-01

    The present study aims to developan automatic method able to track red blood cells (RBCs) trajectories flowing through a microchannel using the Open Source Computer Vision (OpenCV). The developed method is based on optical flux calculation assisted by the maximization of the template-matching product. The experimental results show a good functional performance of this method.

  11. INTERACTION OF INORGANIC MERCURY SALTS WITH MODEL AND RED CELL MEMBRANES: IMPORTANCE OF LIPID BINDING SALTS

    EPA Science Inventory

    The effect induced by two mercury salts, HgCl2 and Hg(NO3)2, on the thermotropic properties of PS model membranes (multilamellar vesicles) and rat red cell membranes was investigated employing 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence polarization. ercury(II) interacts wit...

  12. Mapping viscoelastic properties of healthy and pathological red blood cells at the nanoscale level.

    PubMed

    Ciasca, G; Papi, M; Di Claudio, S; Chiarpotto, M; Palmieri, V; Maulucci, G; Nocca, G; Rossi, C; De Spirito, M

    2015-10-28

    In order to pass through the microcirculation, red blood cells (RBCs) need to undergo extensive deformations and to recover the original shape. This extreme deformability is altered by various pathological conditions. On the other hand, an altered RBC deformability can have major effects on blood flow and can lead to pathological implications. The study of the viscoelastic response of red blood cells to mechanical stimuli is crucial to fully understand deformability changes under pathological conditions. However, the typical erythrocyte biconcave shape hints to a complex and intrinsically heterogeneous mechanical response that must be investigated by using probes at the nanoscale level. In this work, the local viscoelastic behaviour of healthy and pathological red blood cells was probed by Atomic Force Microscopy (AFM). Our results clearly show that the RBC stiffness is not spatially homogeneous, suggesting a strong correlation with the erythrocyte biconcave shape. Moreover, our nanoscale mapping highlights the key role played by viscous forces, demonstrating that RBCs do not behave as pure elastic bodies. The fundamental role played by viscous forces is further strengthened by the comparison between healthy and pathological (diabetes mellitus) RBCs. It is well known that pathological RBCs are usually stiffer than the healthy ones. Our measures unveil a more complex scenario according to which the difference between normal and pathological red blood cells does not merely lie in their stiffness but also in a different dynamical response to external stimuli that is governed by viscous forces. PMID:26415744

  13. Odour discrimination in the olfactory bulb of goldfish: contrasting interactions between mitral cells and ruffed cells.

    PubMed

    Zippel, H P; Gloger, M; Nasser, S; Wilcke, S

    2000-09-29

    Anatomical differences characterizing mitral cells and ruffed cells have been published by T. Kosaka and K. Hama in three teleost species. Physiological responses from both types of relay neurons were recorded extracellularly and simultaneously in the plexiform layer, using a single tungsten microelectrode. During interstimulus intervals mitral cells responded with higher, frequently burst-like impulse rates triggered by the activity of epithelial receptor neurons. Mitral cell activity could be totally suppressed by local anaesthesia of the olfactory epithelium. Ruffed cell impulse rates were low, and each action potential triggered a long-lasting (3-5 ms), continuously varying, summed granule cell potential. During olfactory stimulation with non-familiar stimuli and important biological stimuli such as amino acids, preovulatory and ovulatory pheromones, and a probable alarm pheromone, contrasting interactions between mitral cells and ruffed cells were recorded frequently, which resulted in a drastic intensification of centrally transmitted information. An excitation of mitral cells' activity via granule cells laterally inhibited the ruffed cells' activity, and an inhibition of mitral cells' activity simultaneously 'released' an excitation of ruffed cells. PMID:11079404

  14. Multiplexed fluidic plunger mechanism for the measurement of red blood cell deformability.

    PubMed

    Myrand-Lapierre, Marie-Eve; Deng, Xiaoyan; Ang, Richard R; Matthews, Kerryn; Santoso, Aline T; Ma, Hongshen

    2015-01-01

    The extraordinary deformability of red blood cells gives them the ability to repeatedly transit through the microvasculature of the human body. The loss of this capability is part of the pathology of a wide range of diseases including malaria, hemoglobinopathies, and micronutrient deficiencies. We report on a technique for multiplexed measurements of the pressure required to deform individual red blood cell through micrometer-scale constrictions. This measurement is performed by first infusing single red blood cells into a parallel array of ~1.7 μm funnel-shaped constrictions. Next, a saw-tooth pressure waveform is applied across the constrictions to squeeze each cell through its constriction. The threshold deformation pressure is then determined by relating the pressure-time data with the video of the deformation process. Our key innovation is a self-compensating fluidic network that ensures identical pressures are applied to each cell regardless of its position, as well as the presence of cells in neighboring constrictions. These characteristics ensure the consistency of the measurement process and robustness against blockages of the constrictions by rigid cells and debris. We evaluate this technique using in vitro cultures of RBCs infected with P. falciparum, the parasite that causes malaria, to demonstrate the ability to profile the deformability signature of a heterogeneous sample. PMID:25325848

  15. Method and kit for the selective labeling of red blood cells in whole blood with Tc-99m

    DOEpatents

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1988-07-05

    Disclosed herein are a method and kit for the preparation of [sup 99m]Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available for the reduction of technetium. No Drawings

  16. Method and kit for the selective labeling of red blood cells in whole blood with TC-99M

    DOEpatents

    Srivastava, Suresh C.; Babich, John W.; Straub, Rita; Richards, Powell

    1988-01-01

    Disclosed herein are a method and kit for the preparation of .sup.99m Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for the reduction of technetium.

  17. Active Sodium and Potassium Transport in High Potassium and Low Potassium Sheep Red Cells

    PubMed Central

    Hoffman, P. G.; Tosteson, D. C.

    1971-01-01

    The kinetic characteristics of the ouabain-sensitive (Na + K) transport system (pump) of high potassium (HK) and low potassium (LK) sheep red cells have been investigated. In sodium medium, the curve relating pump rate to external K is sigmoid with half maximal stimulation (K1/2) occurring at 3 mM for both cell types, the maximum pump rate in HK cells being about four times that in LK cells. In sodium-free media, both HK and LK pumps are adequately described by the Michaelis-Menten equation, but the K1/2 for HK cells is 0.6 ± 0.1 mM K, while that for LK is 0.2 ± 0.05 mM K. When the internal Na and K content of the cells was varied by the PCMBS method, it was found that the pump rate of HK cells showed a gradual increase from zero at very low internal Na to a maximum when internal K was reduced to nearly zero (100% Na). In LK cells, on the other hand, no pump activity was detected if Na constituted less than 70% of the total (Na + K) in the cell. Increasing Na from 70 to nearly 100% of the internal cation composition, however, resulted in an exponential increase in pump rate in these cells to about ⅙ the maximum rate observed in HK cells. While changes in internal composition altered the pump rate at saturating concentrations of external K, it had no effect on the apparent affinity of the pumps for external K. These results lead us to conclude that the individual pump sites in the HK and LK sheep red cell membranes must be different. Moreover, we believe that these data contribute significantly to defining the types of mechanism which can account for the kinetic characteristics of (Na + K) transport in sheep red cells and perhaps in other systems. PMID:5112660

  18. Splenic red pulp macrophages are intrinsically superparamagnetic and contaminate magnetic cell isolates.

    PubMed

    Franken, Lars; Klein, Marika; Spasova, Marina; Elsukova, Anna; Wiedwald, Ulf; Welz, Meike; Knolle, Percy; Farle, Michael; Limmer, Andreas; Kurts, Christian

    2015-01-01

    A main function of splenic red pulp macrophages is the degradation of damaged or aged erythrocytes. Here we show that these macrophages accumulate ferrimagnetic iron oxides that render them intrinsically superparamagnetic. Consequently, these cells routinely contaminate splenic cell isolates obtained with the use of MCS, a technique that has been widely used in immunological research for decades. These contaminations can profoundly alter experimental results. In mice deficient for the transcription factor SpiC, which lack red pulp macrophages, liver Kupffer cells take over the task of erythrocyte degradation and become superparamagnetic. We describe a simple additional magnetic separation step that avoids this problem and substantially improves purity of magnetic cell isolates from the spleen. PMID:26260698

  19. Splenic red pulp macrophages are intrinsically superparamagnetic and contaminate magnetic cell isolates

    PubMed Central

    Franken, Lars; Klein, Marika; Spasova, Marina; Elsukova, Anna; Wiedwald, Ulf; Welz, Meike; Knolle, Percy; Farle, Michael; Limmer, Andreas; Kurts, Christian

    2015-01-01

    A main function of splenic red pulp macrophages is the degradation of damaged or aged erythrocytes. Here we show that these macrophages accumulate ferrimagnetic iron oxides that render them intrinsically superparamagnetic. Consequently, these cells routinely contaminate splenic cell isolates obtained with the use of MCS, a technique that has been widely used in immunological research for decades. These contaminations can profoundly alter experimental results. In mice deficient for the transcription factor SpiC, which lack red pulp macrophages, liver Kupffer cells take over the task of erythrocyte degradation and become superparamagnetic. We describe a simple additional magnetic separation step that avoids this problem and substantially improves purity of magnetic cell isolates from the spleen. PMID:26260698

  20. Discovery of molecular markers to discriminate corneal endothelial cells in the human body.

    PubMed

    Yoshihara, Masahito; Ohmiya, Hiroko; Hara, Susumu; Kawasaki, Satoshi; Hayashizaki, Yoshihide; Itoh, Masayoshi; Kawaji, Hideya; Tsujikawa, Motokazu; Nishida, Kohji

    2015-01-01

    The corneal endothelium is a monolayer of hexagonal corneal endothelial cells (CECs) on the inner surface of the cornea. CECs are critical in maintaining corneal transparency through their barrier and pump functions. CECs in vivo have a limited capacity in proliferation, and loss of a significant number of CECs results in corneal edema called bullous keratopathy which can lead to severe visual loss. Corneal transplantation is the most effective method to treat corneal endothelial dysfunction, where it suffers from donor shortage. Therefore, regeneration of CECs from other cell types attracts increasing interests, and specific markers of CECs are crucial to identify actual CECs. However, the currently used markers are far from satisfactory because of their non-specific expression in other cell types. Here, we explored molecular markers to discriminate CECs from other cell types in the human body by integrating the published RNA-seq data of CECs and the FANTOM5 atlas representing diverse range of cell types based on expression patterns. We identified five genes, CLRN1, MRGPRX3, HTR1D, GRIP1 and ZP4 as novel markers of CECs, and the specificities of these genes were successfully confirmed by independent experiments at both the RNA and protein levels. Notably none of them have been documented in the context of CEC function. These markers could be useful for the purification of actual CECs, and also available for the evaluation of the products derived from other cell types. Our results demonstrate an effective approach to identify molecular markers for CECs and open the door for the regeneration of CECs in vitro. PMID:25807145

  1. Discovery of Molecular Markers to Discriminate Corneal Endothelial Cells in the Human Body

    PubMed Central

    Yoshihara, Masahito; Ohmiya, Hiroko; Hara, Susumu; Kawasaki, Satoshi; Hayashizaki, Yoshihide; Itoh, Masayoshi; Kawaji, Hideya; Tsujikawa, Motokazu; Nishida, Kohji

    2015-01-01

    The corneal endothelium is a monolayer of hexagonal corneal endothelial cells (CECs) on the inner surface of the cornea. CECs are critical in maintaining corneal transparency through their barrier and pump functions. CECs in vivo have a limited capacity in proliferation, and loss of a significant number of CECs results in corneal edema called bullous keratopathy which can lead to severe visual loss. Corneal transplantation is the most effective method to treat corneal endothelial dysfunction, where it suffers from donor shortage. Therefore, regeneration of CECs from other cell types attracts increasing interests, and specific markers of CECs are crucial to identify actual CECs. However, the currently used markers are far from satisfactory because of their non-specific expression in other cell types. Here, we explored molecular markers to discriminate CECs from other cell types in the human body by integrating the published RNA-seq data of CECs and the FANTOM5 atlas representing diverse range of cell types based on expression patterns. We identified five genes, CLRN1, MRGPRX3, HTR1D, GRIP1 and ZP4 as novel markers of CECs, and the specificities of these genes were successfully confirmed by independent experiments at both the RNA and protein levels. Notably none of them have been documented in the context of CEC function. These markers could be useful for the purification of actual CECs, and also available for the evaluation of the products derived from other cell types. Our results demonstrate an effective approach to identify molecular markers for CECs and open the door for the regeneration of CECs in vitro. PMID:25807145

  2. Light spectrum regulates cell accumulation during daytime in the raphidophyte Chattonella antiqua causing noxious red tides.

    PubMed

    Shikata, Tomoyuki; Matsunaga, Shigeru; Kuwahara, Yusuke; Iwahori, Sho; Nishiyama, Yoshitaka

    2016-07-01

    Most marine raphidophyte species cause noxious red tides in temperate coastal areas around the world. It is known that swimming abilities enable raphidophytes to accumulation of cells and to actively acquire light at surface layers and nutrients over a wide depth range. However, it remains unclear how the swimming behavior is affected by environmental conditions, especially light condition. In the present study, we observed the accumulation of the harmful red-tide raphidophyte Chattonella antiqua under various light conditions during the daytime in the laboratory. When exposed to ultraviolet-A/blue light (320-480nm) or red light (640-680nm) from above, cells moved downward. In the case of blue light (455nm), cells started to swim downward after 5-15min of irradiation at a photon flux density≥10μmolm(-2)s(-1). When exposed to monochromatic lights (400-680nm) from the side, cells moved away from the blue light source and then descended, but just moved downward under red light. However, mixing of green/orange light (520-630nm) diminished the effects of blue light. When exposed to a mixture of 30μmolm(-2)s(-1) of blue light (440nm) and ≥6μmolm(-2)s(-1) of yellow light (560nm) from above, cells did not move downward. These results indicate that blue light induces negative phototaxis and ultraviolet-A/blue and red lights induce descending, and green/orange light cancels out their effects in C. antiqua. PMID:27107332

  3. Paper-based assay for red blood cell antigen typing by the indirect antiglobulin test.

    PubMed

    Yeow, Natasha; McLiesh, Heather; Guan, Liyun; Shen, Wei; Garnier, Gil

    2016-07-01

    A rapid and simple paper-based elution assay for red blood cell antigen typing by the indirect antiglobulin test (IAT) was established. This allows to type blood using IgG antibodies for the important blood groups in which IgM antibodies do not exist. Red blood cells incubated with IgG anti-D were washed with saline and spotted onto the paper assay pre-treated with anti-IgG. The blood spot was eluted with an elution buffer solution in a chromatography tank. Positive samples were identified by the agglutinated and fixed red blood cells on the original spotting area, while red blood cells from negative samples completely eluted away from the spot of origin. Optimum concentrations for both anti-IgG and anti-D were identified to eliminate the washing step after the incubation phase. Based on the no-washing procedure, the critical variables were investigated to establish the optimal conditions for the paper-based assay. Two hundred ten donor blood samples were tested in optimal conditions for the paper test with anti-D and anti-Kell. Positive and negative samples were clearly distinguished. This assay opens up new applications of the IAT on paper including antibody detection and blood donor-recipient crossmatching and extends its uses into non-blood typing applications with IgG antibody-based diagnostics. Graphical abstract A rapid and simple paper-based assay for red blood cell antigen typing by the indirect antiglobulin test. PMID:27185543

  4. Network-of-queues approach to B-cell-receptor affinity discrimination

    NASA Astrophysics Data System (ADS)

    Felizzi, Federico; Comoglio, Federico

    2012-06-01

    The immune system is one of the most complex signal processing machineries in biology. The adaptive immune system, consisting of B and T lymphocytes, is activated in response to a large spectrum of pathogen antigens. B cells recognize and bind the antigen through B-cell receptors (BCRs) and this is fundamental for B-cell activation. However, the system response is dependent on BCR-antigen affinity values that span several orders of magnitude. Moreover, the ability of the BCR to discriminate between affinities at the high end (e.g., 109M-1-1010M-1) challenges the formulation of a mathematical model able to robustly separate these affinity-dependent responses. Queuing theory enables the analysis of many related processes, such as those resulting from the stochasticity of protein binding and unbinding events. Here we define a network of queues, consisting of BCR early signaling states and transition rates related to the propensity of molecular aggregates to form or disassemble. By considering the family of marginal distributions of BCRs in a given signaling state, we report a significant separation (measured as Jensen-Shannon divergence) that arises from a broad spectrum of antigen affinities.

  5. Network-of-queues approach to B-cell-receptor affinity discrimination.

    PubMed

    Felizzi, Federico; Comoglio, Federico

    2012-06-01

    The immune system is one of the most complex signal processing machineries in biology. The adaptive immune system, consisting of B and T lymphocytes, is activated in response to a large spectrum of pathogen antigens. B cells recognize and bind the antigen through B-cell receptors (BCRs) and this is fundamental for B-cell activation. However, the system response is dependent on BCR-antigen affinity values that span several orders of magnitude. Moreover, the ability of the BCR to discriminate between affinities at the high end (e.g., 10^{9}M^{-1}-10^{10}M^{-1}) challenges the formulation of a mathematical model able to robustly separate these affinity-dependent responses. Queuing theory enables the analysis of many related processes, such as those resulting from the stochasticity of protein binding and unbinding events. Here we define a network of queues, consisting of BCR early signaling states and transition rates related to the propensity of molecular aggregates to form or disassemble. By considering the family of marginal distributions of BCRs in a given signaling state, we report a significant separation (measured as Jensen-Shannon divergence) that arises from a broad spectrum of antigen affinities. PMID:23005146

  6. Long-term remission of pure red cell aplasia after plasma exchange and lymphocytapheresis.

    PubMed

    Berlin, G; Liedén, G

    1986-01-01

    A 57-year-old man with idiopathic pure red cell aplasia went into remission after plasma exchange. He relapsed after 5 months and then failed to respond to treatment with intensive plasma exchange and immunosuppressive agents. Because of a high proportion of T-suppressor cells in the peripheral blood he was treated with lymphocytapheresis in addition to the previous treatment. The patient achieved a long-term haematological remission which has now persisted for more than 3 yr. PMID:2937136

  7. The effect of osmotic pressure of aqueous PEG solutions on red blood cells.

    PubMed

    Herrmann, A; Arnold, K; Pratsch, L

    1985-08-01

    A drastic increase of the intracellular microviscosity of red blood cells in the presence of polyethylene glycol (PEG) was established by electron spin resonance using the small spin label molecule 2,2,6,6-tetramethyl-piperidine-N-oxyl-4-one (TEMPONE). The effective osmotic pressure of PEG solutions stressing the cells was estimated by comparison with those cytoplasmic rotational correlation times of TEMPONE measured in NaCl or sucrose containing media of known osmotic pressure. PMID:2998502

  8. Healthy and unhealthy red blood cell detection in human blood smears using neural networks.

    PubMed

    Elsalamony, Hany A

    2016-04-01

    One of the most common diseases that affect human red blood cells (RBCs) is anaemia. To diagnose anaemia, the following methods are typically employed: an identification process that is based on measuring the level of haemoglobin and the classification of RBCs based on a microscopic examination in blood smears. This paper presents a proposed algorithm for detecting and counting three types of anaemia-infected red blood cells in a microscopic coloured image using circular Hough transform and morphological tools. Anaemia cells include sickle, elliptocytosis, microsite cells and cells with unknown shapes. Additionally, the resulting data from the detection process have been analysed by a prevalent data analysis technique: the neural network. The experimental results for this model have demonstrated high accuracy for analysing healthy/unhealthy cells. This algorithm has achieved a maximum detection of approximately 97.8% of all cells in 21 microscopic images. Effectiveness rates of 100%, 98%, 100%, and 99.3% have been achieved using neural networks for sickle cells, elliptocytosis cells, microsite cells and cells with unknown shapes, respectively. PMID:26867209

  9. Cell-to-Cell Trafficking of Macromolecules through Plasmodesmata Potentiated by the Red Clover Necrotic Mosaic Virus Movement Protein.

    PubMed

    Fujiwara, T.; Giesman-Cookmeyer, D.; Ding, B.; Lommel, S. A.; Lucas, W. J.

    1993-12-01

    Direct evidence is presented for cell-to-cell trafficking of macromolecules via plasmodesmata in higher plants. The fluorescently labeled 35-kD movement protein of red clover necrotic mosaic virus (RCNMV) trafficked rapidly from cell to cell when microinjected into cowpea leaf mesophyll cells. Furthermore, this protein potentiated rapid cell-to-cell trafficking of RCNMV RNA, but not DNA. Electron microscopic studies demonstrated that the 35-kD movement protein does not unfold the RCNMV RNA molecules. Thus, if unfolding of RNA is necessary for cell-to-cell trafficking, it may well involve participation of endogenous cellular factors. These findings support the hypothesis that trafficking of macromolecules is a normal plasmodesmal function, which has been usurped by plant viruses for their cell-to-cell spread. PMID:12271056

  10. Autologous red blood cells potentiate antibody synthesis by unfractionated human mononuclear cell cultures.

    PubMed

    Rugeles, M T; La Via, M; Goust, J M; Kilpatrick, J M; Hyman, B; Virella, G

    1987-08-01

    We have tried to determine the most favourable conditions for the in vitro induction of specific antibody (Ab) responses to tetanus toxoid (TT) and keyhole limpet haemocyanin (KLH). Human peripheral blood mononuclear cells (PBMNC) were obtained from normal volunteers and stimulated with PWM, TT, KLH, and mixtures of PWM and antigens in the presence or absence of autologous red blood cells (RBC) (1:50 ratio of PBMNC/RBC). The cultures were harvested on day 11; immunoglobulins were determined immunonephelometrically and Ab levels by ELISA with human antibodies used for calibration. While anti-TT responses were easy to induce with PBMNC from recently boosted individuals, the production of anti-TT from PBMNC obtained from non-recently boosted individuals was only possible when PBMNC were stimulated with TT and PWM in the presence of autologous RBC. Similarly, anti-KLH responses were easier to induce with PBMNC from an immune donor; maximal response was observed after stimulation with PWM + KLH in the presence of autologous RBC. Stimulation of primary anti-KLH responses with PBMNC from non-immune donors was only successful when the cells were stimulated with KLH + PWM in the presence of autologous RBC. The potentiation of human B-cell responses with autologous RBC can be abrogated by pretreatment of PBMNC with anti-CD2 antibodies and is associated with increased expression of IL-2 receptors and increased production of gamma interferon (IFN-gamma). However, addition of IFN-gamma in different doses and at different times to PWM-stimulated PBMNC cultures was not as effective as addition of RBC in enhancing the production of immunoglobulin and antibody. PMID:3114872

  11. Activated polymorphonuclear cells increase sickle red blood cell retention in lung: role of phospholipids.

    PubMed

    Haynes, Johnson; Obiako, Boniface

    2002-01-01

    This study investigates the role of the activated polymorphonuclear cell (APMN) products on sickle red blood cell (SRBC) retention/adherence in the pulmonary circulation. Isolated rat lungs were perfused with (51)Cr-labeled normal RBCs (NRBC) or SRBCs (10% hematocrit) suspensions +/- PMNs. Specific activities of lung and perfusate were measured and retention (the number of SRBC/g lung) was calculated. SRBC retention was 3.5 times greater than NRBC retention. PMN activation was required to increase SRBC retention. Supernatants from APMN increased SRBC retention, which suggested soluble products such as oxidants, PAF, and/or leukotriene (LTB(4)) are involved. Heat inactivation of PMN NADPH oxidase had no effect on retention. Whereas neither platelet-activating factor (PAF) nor LTB(4) (secreted by APMN) increased SRBC retention, PAF+LTB(4) did. The PAF antagonist, WEB-2170, attenuated SRBC retention mediated by PAF+LTB(4) and APMNs. Similarly, zileuton (5-lipoxygenase inhibitor) attenuated APMN-mediated SRBC retention. We conclude the concomitant release of PAF and LTB(4) from APMN is involved in the initiation of microvascular occlusion by SRBCs in the perfused rat lung. PMID:11748055

  12. Effectiveness of two synthetic fiber filters for removing white cells from AS-1 red cells.

    PubMed

    Pikul, F J; Farrar, R P; Boris, M B; Estok, L; Marlo, D; Wildgen, M; Chaplin, H

    1989-09-01

    Two commercially available synthetic fiber filters were studied for their effectiveness at removing white cells (WBCs) from AS-1-preserved red cells (RBCs) stored less than or equal to 14 days. In all, 65 filtrations were performed. An automated microprocessor-controlled hydraulic system designed for use with cellulose acetate fiber filters was employed to prepare filtered RBCs before release for transfusion. Studies were also carried out on polyester fiber filters, which are designed to be used in-line during transfusion. Residual WBCs were below the accurate counting range of Coulter counters and of conventional manual chamber counts. An isosmotic ammonium chloride RBC lysis method, plus a modified chamber counting technique, permitted a 270-fold increase over the number of WBCs counted by the conventional manual method. For the polyester fiber-filtered products, residual WBCs per unit were not affected by speed of filtration, prior length of storage, or mechanical tapping during filtration. The effectiveness of WBC removal (mean 99.7%), total residual WBCs (means, 4.8 and 5.5 x 10(6], and RBC recovery (mean, 93%) was the same for both filters. The majority of residual WBCs were lymphocytes. WBC removal and RBC recovery were strikingly superior to results reported with nonfiltration methods. PMID:2505411

  13. Cell morphology-based classification of red blood cells using holographic imaging informatics

    PubMed Central

    Yi, Faliu; Moon, Inkyu; Javidi, Bahram

    2016-01-01

    We present methods that automatically select a linear or nonlinear classifier for red blood cell (RBC) classification by analyzing the equality of the covariance matrices in Gabor-filtered holographic images. First, the phase images of the RBCs are numerically reconstructed from their holograms, which are recorded using off-axis digital holographic microscopy (DHM). Second, each RBC is segmented using a marker-controlled watershed transform algorithm and the inner part of the RBC is identified and analyzed. Third, the Gabor wavelet transform is applied to the segmented cells to extract a series of features, which then undergo a multivariate statistical test to evaluate the equality of the covariance matrices of the different shapes of the RBCs using selected features. When these covariance matrices are not equal, a nonlinear classification scheme based on quadratic functions is applied; otherwise, a linear classification is applied. We used the stomatocyte, discocyte, and echinocyte RBC for classifier training and testing. Simulation results demonstrated that 10 of the 14 RBC features are useful in RBC classification. Experimental results also revealed that the covariance matrices of the three main RBC groups are not equal and that a nonlinear classification method has a much lower misclassification rate. The proposed automated RBC classification method has the potential for use in drug testing and the diagnosis of RBC-related diseases. PMID:27375953

  14. Cell morphology-based classification of red blood cells using holographic imaging informatics.

    PubMed

    Yi, Faliu; Moon, Inkyu; Javidi, Bahram

    2016-06-01

    We present methods that automatically select a linear or nonlinear classifier for red blood cell (RBC) classification by analyzing the equality of the covariance matrices in Gabor-filtered holographic images. First, the phase images of the RBCs are numerically reconstructed from their holograms, which are recorded using off-axis digital holographic microscopy (DHM). Second, each RBC is segmented using a marker-controlled watershed transform algorithm and the inner part of the RBC is identified and analyzed. Third, the Gabor wavelet transform is applied to the segmented cells to extract a series of features, which then undergo a multivariate statistical test to evaluate the equality of the covariance matrices of the different shapes of the RBCs using selected features. When these covariance matrices are not equal, a nonlinear classification scheme based on quadratic functions is applied; otherwise, a linear classification is applied. We used the stomatocyte, discocyte, and echinocyte RBC for classifier training and testing. Simulation results demonstrated that 10 of the 14 RBC features are useful in RBC classification. Experimental results also revealed that the covariance matrices of the three main RBC groups are not equal and that a nonlinear classification method has a much lower misclassification rate. The proposed automated RBC classification method has the potential for use in drug testing and the diagnosis of RBC-related diseases. PMID:27375953

  15. The Laser-assisted Optical Rotational Cell Analyzer (LORCA) as red blood cell aggregometer.

    PubMed

    Hardeman, M R; Dobbe, J G; Ince, C

    2001-01-01

    The Laser-assisted Optical Rotational Cell Analyzer (LORCA) is unique in its capacity to measure at least two important hemorheological parameters, i.e., deformability of red blood cells (RBC) as well as their aggregation behaviour. In this communication the main principles and characteristics of the aggregometer mode of this instrument are described. Via syllectometry (i.e., laser backscatter versus time), the method allows the measure of both static and kinetic parameters of the aggregation process, e.g., total extent of aggregation, aggregation half time and a combination of these, defined as aggregation index. When the syllectogram deviates from that representing normal rouleaux formation, e.g., in the case of RBC clump formation, this is signalled by a fit error. Maximal flexibility is obtained by various options like an automated re-iteration procedure (which enables to measure the aggregation tendency and/or the aggregate stability) and aggregation at low shear rate. Experiments dealing with reproducibility, stability and sensitivity of the instrument are described. The latter include a few "classic" methods for inducing subtle changes in RBC aggregation behaviour both regarding cellular factors (heat treatment) and changes in medium constituents (fibrinogen, dextrans).It can be concluded that the aggregometer mode of the LORCA considerably increases the feasibility of this instrument for hemorheological investigations. PMID:11790865

  16. Removal of malaria-infected red blood cells using magnetic cell separators: A computational study.

    PubMed

    Kim, Jeongho; Massoudi, Mehrdad; Antaki, James F; Gandini, Alberto

    2012-02-15

    High gradient magnetic field separators have been widely used in a variety of biological applications. Recently, the use of magnetic separators to remove malaria-infected red blood cells (pRBCs) from blood circulation in patients with severe malaria has been proposed in a dialysis-like treatment. The capture efficiency of this process depends on many interrelated design variables and constraints such as magnetic pole array pitch, chamber height, and flow rate. In this paper, we model the malaria-infected RBCs (pRBCs) as paramagnetic particles suspended in a Newtonian fluid. Trajectories of the infected cells are numerically calculated inside a micro-channel exposed to a periodic magnetic field gradient. First-order stiff ordinary differential equations (ODEs) governing the trajectory of particles under periodic magnetic fields due to an array of wires are solved numerically using the 1(st) -5(th) order adaptive step Runge-Kutta solver. The numerical experiments show that in order to achieve a capture efficiency of 99% for the pRBCs it is required to have a longer length than 80 mm; this implies that in principle, using optimization techniques the length could be adjusted, i.e., shortened to achieve 99% capture efficiency of the pRBCs. PMID:22345827

  17. Relative deformability of red blood cells in sickle cell trait and sickle cell anemia by trapping and dragging

    NASA Astrophysics Data System (ADS)

    Solomon, Rance; Cooper, James; Welker, Gabriel; Aguilar, Elaura; Flanagan, Brooke; Pennycuff, Chelsey; Scott, David; Farone, Anthony; Farone, Mary; Erenso, Daniel; Mushi, Robert; del Pilar Aguinaga, Maria

    2013-06-01

    Genetic mutation of the β-globin gene or inheritance of this mutated gene changes the chemical composition of the oxygen-carrying hemoglobin molecule that could lead to either the heterozygote genotype, resulting in sickle cell trait (SCT), or the homozygote genotype, resulting in sickle cell anemia (SCA). These mutations could affect the reversible elastic deformations of the red blood cells (RBCs) which are vital for biological functions. We have investigated this effect by studying the differences in the deformability of RBCs from blood samples of an individual with SCT and an untreated patient with SCA along with hemoglobin quantitation of each blood sample. Infrared 1064 nm laser trap force along with drag shear force are used to induce deformation in the RBCs. Ultra2-High Performance Liquid Chromatography (UHPLC) is used for the hemoglobin quantitation.

  18. Strengths and Weaknesses of Recently Engineered Red Fluorescent Proteins Evaluated in Live Cells Using Fluorescence Correlation Spectroscopy

    PubMed Central

    Siegel, Amanda P.; Baird, Michelle A.; Davidson, Michael W.; Day, Richard N.

    2013-01-01

    The scientific community is still looking for a bright, stable red fluorescent protein (FP) as functional as the current best derivatives of green fluorescent protein (GFP). The red FPs exploit the reduced background of cells imaged in the red region of the visible spectrum, but photophysical short comings have limited their use for some spectroscopic approaches. Introduced nearly a decade ago, mCherry remains the most often used red FP for fluorescence correlation spectroscopy (FCS) and other single molecule techniques, despite the advent of many newer red FPs. All red FPs suffer from complex photophysics involving reversible conversions to a dark state (flickering), a property that results in fairly low red FP quantum yields and potential interference with spectroscopic analyses including FCS. The current report describes assays developed to determine the best working conditions for, and to uncover the shortcoming of, four recently engineered red FPs for use in FCS and other diffusion and spectroscopic studies. All five red FPs assayed had potential shortcomings leading to the conclusion that the current best red FP for FCS is still mCherry. The assays developed here aim to enable the rapid evaluation of new red FPs and their smooth adaptation to live cell spectroscopic microscopy and nanoscopy. PMID:24129172

  19. Men with Sickle Cell Anemia and Priapism Exhibit Increased Hemolytic Rate, Decreased Red Blood Cell Deformability and Increased Red Blood Cell Aggregate Strength

    PubMed Central

    Cita, Kizzy-Clara; Brureau, Laurent; Lemonne, Nathalie; Billaud, Marie; Connes, Philippe; Ferdinand, Séverine; Tressières, Benoit; Tarer, Vanessa; Etienne-Julan, Maryse; Blanchet, Pascal; Elion, Jacques; Romana, Marc

    2016-01-01

    Objectives To investigate the association between priapism in men with sickle cell anemia (SCA) and hemorheological and hemolytical parameters. Materials and Methods Fifty-eight men with SCA (median age: 38 years) were included; 28 who had experienced priapism at least once during their life (priapism group) and 30 who never experienced this complication (control group). Twenty-two patients were treated with hydroxycarbamide, 11 in each group. All patients were at steady state at the time of inclusion. Hematological and biochemical parameters were obtained through routine procedures. The Laser-assisted Optical Rotational Cell Analyzer was used to measure red blood cell (RBC) deformability at 30 Pa (ektacytometry) and RBC aggregation properties (laser backscatter versus time). Blood viscosity was measured at a shear rate of 225 s-1 using a cone/plate viscometer. A principal component analysis was performed on 4 hemolytic markers (i.e., lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), total bilirubin (BIL) levels and reticulocyte (RET) percentage) to calculate a hemolytic index. Results Compared to the control group, patients with priapism exhibited higher ASAT (p = 0.01), LDH (p = 0.03), RET (p = 0.03) levels and hemolytic indices (p = 0.02). Higher RBC aggregates strength (p = 0.01) and lower RBC deformability (p = 0.005) were observed in patients with priapism compared to controls. After removing the hydroxycarbamide-treated patients, RBC deformability (p = 0.01) and RBC aggregate strength (p = 0.03) were still different between the two groups, and patients with priapism exhibited significantly higher hemolytic indices (p = 0.01) than controls. Conclusion Our results confirm that priapism in SCA is associated with higher hemolytic rates and show for the first time that this complication is also associated with higher RBC aggregate strength and lower RBC deformability. PMID:27145183

  20. Direct Cytoskeleton Forces Cause Membrane Softening in Red Blood Cells

    PubMed Central

    Rodríguez-García, Ruddi; López-Montero, Iván; Mell, Michael; Egea, Gustavo; Gov, Nir S.; Monroy, Francisco

    2015-01-01

    Erythrocytes are flexible cells specialized in the systemic transport of oxygen in vertebrates. This physiological function is connected to their outstanding ability to deform in passing through narrow capillaries. In recent years, there has been an influx of experimental evidence of enhanced cell-shape fluctuations related to metabolically driven activity of the erythroid membrane skeleton. However, no direct observation of the active cytoskeleton forces has yet been reported to our knowledge. Here, we show experimental evidence of the presence of temporally correlated forces superposed over the thermal fluctuations of the erythrocyte membrane. These forces are ATP-dependent and drive enhanced flickering motions in human erythrocytes. Theoretical analyses provide support for a direct force exerted on the membrane by the cytoskeleton nodes as pulses of well-defined average duration. In addition, such metabolically regulated active forces cause global membrane softening, a mechanical attribute related to the functional erythroid deformability. PMID:26083919

  1. Collective synchronization of self/non-self discrimination in T cell activation, across multiple spatio-temporal scales

    NASA Astrophysics Data System (ADS)

    Altan-Bonnet, Gregoire

    The immune system is a collection of cells whose function is to eradicate pathogenic infections and malignant tumors while protecting healthy tissues. Recent work has delineated key molecular and cellular mechanisms associated with the ability to discriminate self from non-self agents. For example, structural studies have quantified the biophysical characteristics of antigenic molecules (those prone to trigger lymphocyte activation and a subsequent immune response). However, such molecular mechanisms were found to be highly unreliable at the individual cellular level. We will present recent efforts to build experimentally validated computational models of the immune responses at the collective cell level. Such models have become critical to delineate how higher-level integration through nonlinear amplification in signal transduction, dynamic feedback in lymphocyte differentiation and cell-to-cell communication allows the immune system to enforce reliable self/non-self discrimination at the organism level. In particular, we will present recent results demonstrating how T cells tune their antigen discrimination according to cytokine cues, and how competition for cytokine within polyclonal populations of cells shape the repertoire of responding clones. Additionally, we will present recent theoretical and experimental results demonstrating how competition between diffusion and consumption of cytokines determine the range of cell-cell communications within lymphoid organs. Finally, we will discuss how biochemically explicit models, combined with quantitative experimental validation, unravel the relevance of new feedbacks for immune regulations across multiple spatial and temporal scales.

  2. Efficient two-photon fluorescent probe with red emission for imaging of thiophenols in living cells and tissues.

    PubMed

    Liu, Hong-Wen; Zhang, Xiao-Bing; Zhang, Jing; Wang, Qian-Qian; Hu, Xiao-Xiao; Wang, Peng; Tan, Weihong

    2015-09-01

    Thiophenols, a class of highly toxic and pollutant compounds, are widely used in industrial production. Some aliphatic thiols play important roles in living organisms. Therefore, the development of efficient methods to discriminate thiophenols from aliphatic thiols is of great importance. Although several one-photon fluorescent probes have been reported for thiophenols, two-photon fluorescent probes are more favorable for biological imaging due to its low background fluorescence, deep penetration depth, and so on. In this work, a two-photon fluorescent probe for thiophenols, termed NpRb1, has been developed for the first time by employing 2,4-dinitrobenzene-sulfonate (DNBS) as a recognition unit (also a fluorescence quencher) and a naphthalene-BODIPY-based through-bond energy transfer (TBET) cassette as a fluorescent reporter. The TBET system consists of a D-π-A structured two-photon naphthalene fluorophore and a red-emitting BODIPY. It displayed highly energy transfer efficiency (93.5%), large pseudo-Stokes shifts upon one-photon excitation, and red fluorescence emission (λem = 586 nm), which is highly desirable for bioimaging applications. The probe exhibited a 163-fold thiophenol-triggered two-photon excited fluorescence enhancement at 586 nm. It showed a high selectivity and excellent sensitivity to thiophenols, with a detection limit of 4.9 nM. Moreover, it was successfully applied for practical detection of thiophenol in water samples with a good recovery, two-photon imaging of thiophenol in living cells, and tissues with tissue-imaging depths of 90-220 μm, demonstrating its practical application in environmental samples and biological systems. PMID:26228351

  3. Surface-emitting superconductor laser spectroscopy for characterizing normal and sickled red blood cells

    SciTech Connect

    Gourley, P.L.; Meissner, K.E.; Brennan, T.M.; Hammons, B.E.; Gourley, M.F.

    1995-02-01

    We have developed a new intracavity laser technique that uses a living or a fixed cell as an integral component of the laser. The cells are placed on an AlGaAs/GaAs surface-emitting semiconductor wafer and covered with a glass dielectric mirror to form a laser resonator. In this arrangement, the cells serve as optical waveguides (or lens elements) to confine (or focus) light generated in the resonator by the semiconductor. Because of the high transparency, the cells aid the lasing process to generate laser light. This ultra sensitive laser provides a novel imaging/spectroscopic technique for histologic examination which we demonstrate with normal and sickled human red blood cells. Extremely high contrast microscopic images of the cells are observed near 830-850 nm. These images correspond to electromagnetic modes of cell structures and are sensitive to shape of the cell. Using a high resolution spectrometer, we resolve the light emitted from these images into very narrow spectral peaks associated with the lasing modes. Analysis of the spectra reveals that the distribution of peaks is quite different for normal and sickled red blood cells. This technique, in a more developed form, may be useful for the rapid analysis of other kinds of normal and abnormal cells.

  4. Efficient Dye-Sensitized Solar Cells Using Red Turnip and Purple Wild Sicilian Prickly Pear Fruits

    PubMed Central

    Calogero, Giuseppe; Di Marco, Gaetano; Cazzanti, Silvia; Caramori, Stefano; Argazzi, Roberto; Di Carlo, Aldo; Bignozzi, Carlo Alberto

    2010-01-01

    Dye-sensitized solar cells (DSSCs) were assembled by using the bougainvillea flowers, red turnip and the purple wild Sicilian prickly pear fruit juice extracts as natural sensitizers of TiO2 films. The yellow orange indicaxanthin and the red purple betacyanins are the main components in the cocktail of natural dyes obtained from these natural products. The best overall solar energy conversion efficiency of 1.7% was obtained, under AM 1.5 irradiation, with the red turnip extract, that showed a remarkable current density (Jsc = 9.5 mA/cm2) and a high IPCE value (65% at λ = 470 nm). Also the purple extract of the wild Sicilian prickly pear fruit showed interesting performances, with a Jsc of 9.4 mA/cm2, corresponding to a solar to electrical power conversion of 1.26%. PMID:20162014

  5. Application of DNA-based forensic analysis for the detection of homologous transfusion of whole blood and of red blood cell concentrates in doping control.

    PubMed

    Stampella, Alessandra; Di Marco, Sabrina; Pirri, Daniela; de la Torre, Xavier; Botrè, Francesco; Donati, Francesco

    2016-08-01

    In this work we present the application of a method for the identification of homologous blood transfusions using forensic genetic techniques based on DNA typing. Ex vivo mixtures of human blood samples - either whole blood or red blood cell concentrates - simulating homologous blood transfusions at different percentages of the donor were typed for a panel of 16 highly variable DNA short tandem repeats (STR). Tested samples included also mixtures, which gave false-negative results if assayed by the reference flow cytofluorimetric method, which is based on the recognition of target antigens located on the membrane of the red blood cell. The recognition of triplets and quadruplets at various loci gave information of the presence of cells belonging to different individuals, as it is the case for homologous blood transfusions. Specificity and sensitivity of the method were assessed in the validation study. The method proved to be unequivocally specific since it was able to recognize all single profiles of each individual, clearly discriminating them from mixtures. Sensitivity resulted as a consequence of the percentage of the donor aliquot in the total volume of the mixture. Although the source of DNA in a blood sample is represented only by nucleated white blood cells, the same procedure resulted effective also in detecting mixtures of red blood cell concentrates (RBCC) from leukodepletion procedure: DNA of the donor from the residual white blood cells resulted still detectable, even if with an expected loss of sensitivity. The proposed approach may contribute to reduce the risk of false-negative results, which may occur using the reference cytofluorimetric method. PMID:27175858

  6. A mesoscopic simulation on distributions of red blood cells in a bifurcating channel

    NASA Astrophysics Data System (ADS)

    Inoue, Yasuhiro; Takagi, Shu; Matsumoto, Yoichiro

    2004-11-01

    Transports of red blood cells (RBCs) or particles in bifurcated channels have been attracting renewed interest since the advent of concepts of MEMS for sorting, analyzing, and removing cells or particles from sample medium. In this talk, we present a result on a transport of red blood cells (RBCs) in a bifurcating channel studied by using a mesoscale simulation technique of immiscible droplets, where RBCs have been modeled as immiscible droplets. The distribution of RBCs is represented by the fractional RBC flux into two daughters as a function of volumetric flow ratio between the daughters. The data obtained in our simulations are examined with a theoretical prediction, in which, we assume an exponential distribution for positions of RBCs in the mother channel. The theoretical predictions show a good agreement with simulation results. A non-uniform distribution of RBCs in the mother channel affects disproportional separation of RBC flux at a bifurcation.

  7. Assessment of oxidant susceptibility of red blood cells in various species based on cell deformability.

    PubMed

    Simmonds, Michael J; Meiselman, Herbert J; Marshall-Gradisnik, Sonya M; Pyne, Michael; Kakanis, Michael; Keane, James; Brenu, Ekua; Christy, Rhys; Baskurt, Oguz K

    2011-01-01

    The present study was designed to investigate the oxidant susceptibility of red blood cells (RBC) from four species (echidna, human, koala, Tasmanian devil) based on changes in cellular deformability. These species were specifically chosen based on differences in lifestyle and/or biology associated with varied levels of oxidative stress. The major focus was the influence of superoxide radicals generated within the cell (phenazine methosulfate, PMS, 50 μM) or in the extracellular medium (xanthine oxidase-hypoxanthine, XO-HX, 0.1 U/ml XO) on RBC deformability at various shear stresses (SS). RBC deformability was assessed by laser-diffraction analysis using a "slit-flow ektacytometer". Both superoxide-generating treatments resulted in significant increases of methemoglobin for all species (p < 0.01), with Tasmanian devil RBC demonstrating the most sensitivity to either treatment. PMS caused impaired RBC deformability for all species, but vast interspecies variations were observed: human and koala cells exhibited a similar sigmoid-like response to SS, short-beaked echidna values were markedly lower and only increased slightly with SS, while Tasmanian devil RBC were extremely rigid. The effect of XO-HX on RBC deformability was less when compared with PMS (i.e., smaller increase in rigidity) with the exception of Tasmanian devil RBC which exhibited essentially no deformation even at the highest SS; Tasmanian devil RBC response to XO-HX was thus comparable to that observed with PMS. Our findings indicate that ektacytometry can be used to determine the oxidant susceptibility of RBC from different species which varies significantly among mammals representing diverse lifestyles and evolutionary histories. These differences in susceptibility are consistent with species-specific discrepancies between observed and allometrically-predicted life spans and are compatible with the oxidant theory of aging. PMID:22433570

  8. Red blood cells initiate leukocyte rolling in postcapillary expansions: a lattice Boltzmann analysis.

    PubMed

    Sun, Chenghai; Migliorini, Cristiano; Munn, Lance L

    2003-07-01

    Leukocyte rolling on the vascular endothelium requires initial contact between leukocytes circulating in the blood and the vessel wall. Although specific adhesion mechanisms are involved in leukocyte-endothelium interactions, adhesion patterns in vivo suggest other rheological mechanisms also play a role. Previous studies have proposed that the abundance of leukocyte rolling in postcapillary venules is due to interactions between red blood cells (RBCs) and leukocytes as they enter postcapillary expansions, but the details of the fluid dynamics have not been elucidated. We have analyzed the interactions of red and white blood cells as they flow from a capillary into a postcapillary venule using a lattice Boltzmann approach. This technique provides the complete solution of the flow field and quantification of the particle-particle forces in a relevant geometry. Our results show that capillary-postcapillary venule diameter ratio, RBC configuration, and RBC shape are critical determinants of the initiation of cell rolling in postcapillary venules. The model predicts that an optimal configuration of the trailing red blood cells is required to drive the white blood cell to the wall. PMID:12829477

  9. Influence of Dietary Capsaicin on Redox Status in Red Blood Cells During Human Aging

    PubMed Central

    Kumar, Prabhanshu; Chand, Subhash; Chandra, Pranjal; Maurya, Pawan Kumar

    2015-01-01

    Purpose: Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is a major pungent compound found in hot peppers of the plant genus Capsicum. In vitro effects of dietary capsaicin on redox status in red blood cells during human aging have been explored. Methods: Total antioxidant potential of capsaicin was evaluated using Ferric reducing ability of plasma (FRAP) assay. GSH was measured as per standard protocol. The in vitro effect of capsaicin was evaluated by incubation of the cells in the assay medium with 10-5M capsaicin (final concentration) for 60 min at 37°C. Results: Treatment with capsaicin (10-5M) caused a significant (p < 0.01) increase in GSH level in all age groups. Reduced glutathione (GSH) / Oxidized glutathione (GSSG) ratio measures the redox status of the red blood cell. Significant increase in GSH level due to capsaicin, shift the GSH/GSSG ratio, thus alters the redox status of the cell. Conclusion: The results conclusively prove the efficacy of the antioxidant property of capsaicin and its role in modulating the redox status of red blood cells. This evidence suggests that dietary factors that act as antioxidants to increase GSH level may contribute to a protective effect against age related diseases. This antioxidant effect may, in part, explain the high consumption of capsicum in certain regions of the world. PMID:26819932

  10. Red Blood Cells Initiate Leukocyte Rolling in Postcapillary Expansions: A Lattice Boltzmann Analysis

    PubMed Central

    Sun, Chenghai; Migliorini, Cristiano; Munn, Lance L.

    2003-01-01

    Leukocyte rolling on the vascular endothelium requires initial contact between leukocytes circulating in the blood and the vessel wall. Although specific adhesion mechanisms are involved in leukocyte-endothelium interactions, adhesion patterns in vivo suggest other rheological mechanisms also play a role. Previous studies have proposed that the abundance of leukocyte rolling in postcapillary venules is due to interactions between red blood cells (RBCs) and leukocytes as they enter postcapillary expansions, but the details of the fluid dynamics have not been elucidated. We have analyzed the interactions of red and white blood cells as they flow from a capillary into a postcapillary venule using a lattice Boltzmann approach. This technique provides the complete solution of the flow field and quantification of the particle-particle forces in a relevant geometry. Our results show that capillary-postcapillary venule diameter ratio, RBC configuration, and RBC shape are critical determinants of the initiation of cell rolling in postcapillary venules. The model predicts that an optimal configuration of the trailing red blood cells is required to drive the white blood cell to the wall. PMID:12829477

  11. Shear Stress induced Stretching of Red Blood Cells by Oscillating Bubbles within a Narrow Gap

    NASA Astrophysics Data System (ADS)

    Li, Fenfang; Mohammadzadeh, Milad; Ohl, Claus-Dieter; Claus-Dieter Ohl Team

    2013-11-01

    The flow pattern, especially the boundary layer caused by the expanding/contracting bubble in a narrow gap (15 μm) and the resultant stretching of red blood cells is investigated in this work. High speed recordings show that a red blood cell (biconcave shape, thickness of 1-2 μm) can be elongated to five times its original length by a laser-induced cavitation bubble within the narrow gap. However, flexible cancer cells in suspension (RKO, spherical shape, diameter of 10-15 μm) are hardly elongated under the same experimental condition. We hypothesize that the shear stress at the boundary layer is crucial for this elongation to occur. Therefore, in order to resolve the related fluid dynamics, we conducted numerical simulations using the finite element method (Fluent). The rapidly expanding/contracting vapor bubble is successfully modeled by employing viscosity and surface tension. The transient pressure inside the bubble and the velocity profile of the flow is obtained. We observe strong shear near the upper and lower boundary during the bubble oscillation. The flow fields are compared with analytical solutions to transient and pulsating flows in 2D. In the experiment the red blood cells sit within the lower boundary layer, thus are probably elongated by this strong shear flow. In contrast, the spherical cancer cells are of comparable size to the gap height so that they are lesser affected by this boundary layer flow.

  12. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles

    PubMed Central

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-01-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c+, CD141+ and CD16+ myeloid DCs and CD123+ plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141+ DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  13. Human blood dendritic cell subsets exhibit discriminative pattern recognition receptor profiles.

    PubMed

    Lundberg, Kristina; Rydnert, Frida; Greiff, Lennart; Lindstedt, Malin

    2014-06-01

    Dendritic cells (DCs) operate as the link between innate and adaptive immunity. Their expression of pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and C-type lectin receptors (CLRs), enables antigen recognition and mediates appropriate immune responses. Distinct subsets of human DCs have been identified; however their expression of PRRs is not fully clarified. Expressions of CLRs by DC subpopulations, in particular, remain elusive. This study aimed to identify and compare PRR expressions on human blood DC subsets, including CD1c(+) , CD141(+) and CD16(+) myeloid DCs and CD123(+) plasmacytoid DCs, in order to understand their capacity to recognize different antigens as well as their responsiveness to PRR-directed targeting. Whole blood was obtained from 13 allergic and six non-allergic individuals. Mononuclear cells were purified and multi-colour flow cytometry was used to assess the expression of 10 CLRs and two TLRs on distinct DC subsets. PRR expression levels were shown to differ between DC subsets for each PRR assessed. Furthermore, principal component analysis and random forest test demonstrated that the PRR profiles were discriminative between DC subsets. Interestingly, CLEC9A was expressed at lower levels by CD141(+) DCs from allergic compared with non-allergic donors. The subset-specific PRR expression profiles suggests individual responsiveness to PRR-targeting and supports functional specialization. PMID:24444310

  14. Network-selectivity and stimulus-discrimination in the primary visual cortex: cell-assembly dynamics.

    PubMed

    Bharmauria, Vishal; Bachatene, Lyes; Cattan, Sarah; Brodeur, Simon; Chanauria, Nayan; Rouat, Jean; Molotchnikoff, Stéphane

    2016-01-01

    Visual neurons coordinate their responses in relation to the stimulus; however, the complex interplay between a stimulus and the functional dynamics of an assembly still eludes neuroscientists. To this aim, we recorded cell assemblies from multi-electrodes in the primary visual cortex of anaesthetized cats in response to randomly presented sine-wave drifting gratings whose orientation tilted in 22.5° steps. Cross-correlograms revealed the functional connections at all the tested orientations. We show that a cell-assembly discriminates between orientations by recruiting a 'salient' functional network at every presented orientation, wherein the connections and their strengths (peak-probabilities in the cross-correlogram) change from one orientation to another. Within these assemblies, closely tuned neurons exhibited increased connectivity and connection-strengths compared with differently tuned neurons. Minimal connectivity between untuned neurons suggests the significance of neuronal selectivity in assemblies. This study reflects upon the dynamics of functional connectivity, and brings to the fore the importance of a 'signature' functional network in an assembly that is strictly related to a specific stimulus. It appears that an assembly is the major 'functional unit' of information processing in cortical circuits, rather than the individual neurons. PMID:26469525

  15. Cellular Interrogation: Exploiting Cell-to-Cell Variability to Discriminate Regulatory Mechanisms in Oscillatory Signalling.

    PubMed

    Estrada, Javier; Andrew, Natalie; Gibson, Daniel; Chang, Frederick; Gnad, Florian; Gunawardena, Jeremy

    2016-07-01

    The molecular complexity within a cell may be seen as an evolutionary response to the external complexity of the cell's environment. This suggests that the external environment may be harnessed to interrogate the cell's internal molecular architecture. Cells, however, are not only nonlinear and non-stationary, but also exhibit heterogeneous responses within a clonal, isogenic population. In effect, each cell undertakes its own experiment. Here, we develop a method of cellular interrogation using programmable microfluidic devices which exploits the additional information present in cell-to-cell variation, without requiring model parameters to be fitted to data. We focussed on Ca2+ signalling in response to hormone stimulation, which exhibits oscillatory spiking in many cell types and chose eight models of Ca2+ signalling networks which exhibit similar behaviour in simulation. We developed a nonlinear frequency analysis for non-stationary responses, which could classify models into groups under parameter variation, but found that this question alone was unable to distinguish critical feedback loops. We further developed a nonlinear amplitude analysis and found that the combination of both questions ruled out six of the models as inconsistent with the experimentally-observed dynamics and heterogeneity. The two models that survived the double interrogation were mathematically different but schematically identical and yielded the same unexpected predictions that we confirmed experimentally. Further analysis showed that subtle mathematical details can markedly influence non-stationary responses under parameter variation, emphasising the difficulty of finding a "correct" model. By developing questions for the pathway being studied, and designing more versatile microfluidics, cellular interrogation holds promise as a systematic strategy that can complement direct intervention by genetics or pharmacology. PMID:27367445

  16. Developing red cell flow orientation shown by changes in blood reflectivity.

    PubMed

    McMillan, D E; Utterback, N G; Lee, M M

    1988-01-01

    The rate of onset of erythrocyte flow orientation at normal concentration has not previously been established. Reflectivity of blood and resuspended non-aggregated red cells at normal (41%) and elevated (60%) hematocrit has been used to examine this process. Video recordings were made before, during, and after shearing by bob motion in a cylinder-in-cylinder viscometer at shear rates ranging from 4 to 100 inverse seconds. Unaggregated erythrocytes in PBS, already more reflective than blood before shearing, became even more reflective during shearing even at the lowest shear rate studied. The time required for the increased reflectivity to stabilize was observed to be inversely proportional to shear rate for both blood and resuspended red cells. Reflection became constant after a total shear strain (bob shear rate x time) from 4 to 10 at all shear rates studied. Onset of increased reflection expressed in total shear strain units (an index of overall bob movement) was independent of shear rate in the absence of aggregation. When red cells were studied in native plasma, reflectivity increased as much as 30% during shearing, but always remained below unaggregated red cell reflectivity for the same hematocrit and shear rate. Greater reflectivity of unaggregated red cells persisted after cessation of shearing, while blood's reflectivity dropped progressively over several seconds to its pre-shearing value. The geometry chosen for study and insensitivity to light source composition indicate that specular reflection by red cells near the cup's inner surface is responsible for the increased light return during flow. Maximal rate of rise in reflectivity at all shear rates studied was observed to coincide with blood's previously reported transient shear stress overshoot and to correspond with an overall bob motion that would rotate suspended particles approximately 45 degrees. The close relation of both reflectivity increase and shear stress overshoot to such modest overall

  17. Cardiopulmonary Function following Transfusion of Three Red Blood Cell Products in Elective Abdominal Aortic Aneurysmectomy

    PubMed Central

    Krausz, Michael M.; Dennis, Richard C.; Utsunomiya, Takayoshi; Grindlinger, Gene A.; Vegas, Armando M.; Churchill, W. Hallowell; Mannick, John A.; Valeri, C. Robert; Hechtman, Herbert B.

    1981-01-01

    In order to evaluate the importance of red cell O2 affinity of transfused blood on cardiac performance and adverse effects of transfusion on lung function, a prospective double-blind protocol was used in 27 patients undergoing abdominal aortic aneurysmectomy. Three types of blood were administered: packed red cells (PC), washed red cells (WC) and high 2,3 DPG red cells (2,3 DPG). An average of 4.5 units of blood was used per patient. Transfusion of 2,3 DPG blood resulted in maintenance of in vivo P50 during surgery and an increase to 31.2 torr after operation (p < 0.001). An intraoperative fall in in vivo P50 to 23.2 ± 2.0 torr was observed in patients who were transfused with PC (p < 0.001) and to 25.1 ± 2.6 torr with WC (p < 0.005). A fall in body temperature averaging 2.2 C intraoperatively was noticed in all three groups. After operation, in vitro P50 decreased in patients transfused with PC (p < 0.005) and WC (p < 0.005) while it remained unchanged in the high 2,3 DPG group. This was consistent with the decrease of red cell 2,3 DPG in the PC (p < 0.001) and WC groups (p < 0.01) and maintenance in the 2,3 DPG group. Left ventricular stroke work and volume loading Starling type myocardial performance curves were similar for the three groups. Microaggregates measured by Coulter counting and screen filtration pressure were the same for all three products in samples drawn on both sides of the 40 µm transfusion filter. There was no relationship of transfusion volumes or type of blood product to changes in lung function (physiologic shunting, dynamic compliance and pulmonary arterial pressure) in the three groups of patients. The false negative, β, error of missing a true 25% difference was less than 10%. It is concluded that 2,3 DPG enriched red cells improved oxygen availability, but that a 4.5 unit transfusion of any of the three blood products did not influence lung function or myocardial performance following aneurysmectomy. ImagesFig. 2. PMID:7294931

  18. Ornamental comb colour predicts T-cell-mediated immunity in male red grouse Lagopus lagopus scoticus

    NASA Astrophysics Data System (ADS)

    Mougeot, Francois

    2008-02-01

    Sexual ornaments might reliably indicate the ability to cope with parasites and diseases, and a better ability to mount a primary inflammatory response to a novel challenge. Carotenoid-based ornaments are amongst the commonest sexual signals of birds and often influence mate choice. Because carotenoids are immuno-stimulants, signallers may trade-off allocating these to ornamental colouration or using them for immune responses, so carotenoid-based ornaments might be particularly useful as honest indicators of immuno-compentence. Tetraonid birds, such as the red grouse Lagopus lagopus scoticus, exhibit supra-orbital yellow red combs, a conspicuous ornament which functions in intra- and inter-sexual selection. The colour of combs is due to epidermal pigmentation by carotenoids, while their size is testosterone-dependent. In this study, I investigated whether comb characteristics, and in particular, comb colour, indicated immuno-competence in free-living male red grouse. I assessed T-cell-mediated immunity using a standardised challenge with phytohaemagglutinin. Red grouse combs reflect in the red and in the ultraviolet spectrum of light, which is not visible to humans but that grouse most likely see, so I measured comb colour across the whole bird visible spectrum (300 700 nm) using a reflectance spectrometer. I found that males with bigger and redder combs, but with less ultraviolet reflectance, had greater T-cell-mediated immune response. Comb colour predicted T-cell-mediated immune response better than comb size, indicating that the carotenoid-based colouration of this ornament might reliably signal this aspect of male quality.

  19. Diagnosing basal cell carcinoma in vivo by near-infrared Raman spectroscopy: a Principal Components Analysis discrimination algorithm

    NASA Astrophysics Data System (ADS)

    Silveira, Landulfo, Jr.; Silveira, Fabrício L.; Bodanese, Benito; Pacheco, Marcos Tadeu T.; Zângaro, Renato A.

    2012-02-01

    This work demonstrated the discrimination among basal cell carcinoma (BCC) and normal human skin in vivo using near-infrared Raman spectroscopy. Spectra were obtained in the suspected lesion prior resectional surgery. After tissue withdrawn, biopsy fragments were submitted to histopathology. Spectra were also obtained in the adjacent, clinically normal skin. Raman spectra were measured using a Raman spectrometer (830 nm) with a fiber Raman probe. By comparing the mean spectra of BCC with the normal skin, it has been found important differences in the 800-1000 cm-1 and 1250-1350 cm-1 (vibrations of C-C and amide III, respectively, from lipids and proteins). A discrimination algorithm based on Principal Components Analysis and Mahalanobis distance (PCA/MD) could discriminate the spectra of both tissues with high sensitivity and specificity.

  20. Mechanical Response of Red Blood Cells Entering a Constriction

    NASA Astrophysics Data System (ADS)

    Zeng, Nancy; Ristenpart, William

    2013-11-01

    Most work on RBC dynamic response to hydrodynamic stress has focused on linear velocity gradients. Relatively little experimental work has examined how RBCs respond to pressure driven flow in more complex geometries, such as in an abrupt contraction. Here, we establish the mechanical behaviors of RBCs undergoing a sudden increase in shear stress at the entrance of a narrow constriction. We pumped RBCs through a constriction in an ex vivo microfluidic device and used high speed video to visualize and track the flow behavior of more than 4,000 RBCs. We show that approximately 90% of RBCs undergo one of four distinct modes of motion: stretching, twisting, tumbling, or rolling. Intriguingly, almost 40% of the cells exhibited twisting (rotation around the major axis parallel to the flow direction), a mechanical behavior that is not typically observed in linear velocity gradients. We present detailed statistical analyses on the dynamics of each motion and demonstrate that the behavior is highly sensitive to the location of the RBC within the channel. Finally, we show that the tumbling and rolling motions can be rationalized qualitatively in terms of rigid body rotation, whereas twisting motion cannot, suggesting that twisting is a consequence of the viscoelastic nature of the RBCs.

  1. Red cell genotyping and the future of pretransfusion testing.

    PubMed

    Anstee, David J

    2009-07-01

    Over the past 20 years the molecular bases of almost all the major blood group antigens have been determined. This research has enabled development of DNA-based methods for determining blood group genotype. The most notable application of these DNA-based methods has been for determining fetal blood group in pregnancies when the fetus is at risk for hemolytic disease of the fetus and newborn. The replacement of all conventional serologic methods for pretransfusion testing by molecular methods is not straightforward. For the majority of transfusion recipients matching beyond ABO and D type is unnecessary, and the minority of untransfused patients at risk of alloimmunization who would benefit from more extensively blood group-matched blood cannot be identified reliably. Even if a method to identify persons most likely to make alloantibodies were available, this would not of itself guarantee the provision of extensively phenotype-matched blood for these patients because this is determined by the size and racial composition of blood donations available for transfusion. However, routine use of DNA-based extended phenotyping to provide optimally matched donations for patients with preexisting antibodies or patients with a known predisposition to alloimmunization, such as those with sickle cell disease, is widely used. PMID:19411635

  2. A rapid method to screen for cell-wall mutants using discriminant analysis of Fourier transform infrared spectra.

    PubMed

    Chen, L; Carpita, N C; Reiter, W D; Wilson, R H; Jeffries, C; McCann, M C

    1998-11-01

    We have developed a rapid method to screen large numbers of mutant plants for a broad range of cell wall phenotypes using Fourier transform infrared (FTIR) microspectroscopy of leaves. We established and validated a model that can discriminate between the leaves of wild-type and a previously defined set of cell-wall mutants of Arabidopsis. Exploratory principal component analysis indicated that mutants deficient in different cell-wall sugars can be distinguished from each other. Discrimination of cell-wall mutants from wild-type was independent of variability in starch content or additional unrelated mutations that might be present in a heavily mutagenised population. We then developed an analysis of FTIR spectra of leaves obtained from over 1000 mutagenised flax plants, and selected 59 plants whose spectral variation from wild-type was significantly out of the range of a wild-type population, determined by Mahalanobis distance. Cell wall sugars from the leaves of selected putative mutants were assayed by gas chromatography-mass spectrometry and 42 showed significant differences in neutral sugar composition. The FTIR spectra indicated that six of the remaining 17 plants have altered ester or protein content. We conclude that linear discriminant analysis of FTIR spectra is a robust method to identify a broad range of structural and architectural alterations in cell walls, appearing as a consequence of developmental regulation, environmental adaptation or genetic modification. PMID:9881159

  3. Microfluidic cell sorter for use in developing red fluorescent proteins with improved photostability

    PubMed Central

    Davis, Lloyd M.; Lubbeck, Jennifer L.; Dean, Kevin M.; Palmer, Amy E.; Jimenez, Ralph

    2014-01-01

    This paper presents a novel microfluidic cytometer for mammalian cells that rapidly measures the irreversible photobleaching of red fluorescent proteins expressed within each cell and achieves high purity (>99%) selection of individual cells based on these measurements. The selection is achieved by using sub-millisecond timed control of a piezo-tilt mirror to steer a focused 1064-nm laser spot for optical gradient force switching following analysis of the fluorescence signals from passage of the cell through a series of 532-nm laser beams. In transit through each beam, the fluorescent proteins within the cell undergo conversion to dark states, but the microfluidic chip enables the cell to pass sufficiently slowly that recovery from reversible dark states occurs between beams, thereby enabling irreversible photobleaching to be quantified separately from the reversible dark-state conversion. The microfluidic platform achieves sorting of samples down to sub-millilitre volumes with minimal loss, wherein collected cells remain alive and can subsequently proliferate. The instrument provides a unique first tool for rapid selection of individual mammalian cells on the merits of photostability and is likely to form the basis of subsequent lab-on-a-chip platforms that combine photobleaching with other spectroscopic measurements for on-going research to develop advanced red fluorescent proteins by screening of genetic libraries. PMID:23636097

  4. Characterizations of individual mouse red blood cells parasitized by Babesia microti using 3-D holographic microscopy

    PubMed Central

    Park, HyunJoo; Hong, Sung-Hee; Kim, Kyoohyun; Cho, Shin-Hyeong; Lee, Won-Ja; Kim, Youngchan; Lee, Sang-Eun; Park, YongKeun

    2015-01-01

    Babesia microti causes “emergency” human babesiosis. However, little is known about the alterations in B. microti invaded red blood cells (Bm-RBCs) at the individual cell level. Through quantitative phase imaging techniques based on laser interferometry, we present the simultaneous measurements of structural, chemical, and mechanical modifications in individual mouse Bm-RBCs. 3-D refractive index maps of individual RBCs and in situ parasite vacuoles are imaged, from which total contents and concentration of dry mass are also precisely quantified. In addition, we examine the dynamic membrane fluctuation of Bm-RBCs, which provide information on cell membrane deformability. PMID:26039793

  5. Optical tweezers study of red blood cell aggregation and disaggregation in plasma and protein solutions

    NASA Astrophysics Data System (ADS)

    Lee, Kisung; Kinnunen, Matti; Khokhlova, Maria D.; Lyubin, Evgeny V.; Priezzhev, Alexander V.; Meglinski, Igor; Fedyanin, Andrey A.

    2016-03-01

    Kinetics of optical tweezers (OT)-induced spontaneous aggregation and disaggregation of red blood cells (RBCs) were studied at the level of cell doublets to assess RBC interaction mechanics. Measurements were performed under in vitro conditions in plasma and fibrinogen and fibrinogen + albumin solutions. The RBC spontaneous aggregation kinetics was found to exhibit different behavior depending on the cell environment. In contrast, the RBC disaggregation kinetics was similar in all solutions qualitatively and quantitatively, demonstrating a significant contribution of the studied proteins to the process. The impact of the study on assessing RBC interaction mechanics and the protein contribution to the reversible RBC aggregation process is discussed.

  6. Permeability and reflection coefficients of urea and small amides in the human red cell.

    PubMed

    Toon, M R; Solomon, A K

    1996-09-01

    Measurement of the transport parameters that govern the passage of urea and amides across the red cell membrane leads to important questions about transport of water. It had initially been thought that small protein channels, permeable to water and small solutes, traversed the membrane (see Solomon, 1987). Recently, however, very strong evidence has been presented that the 28 kDa protein, CHIP28, found in the red cell membrane, is the locus of the water channel (see Agre et al., 1993). CHIP28 transports water very rapidly but does not transport small nonelectrolytes such as urea. The irreversible thermodynamic parameter, sigma i, the reflection coefficient, is a measure of the relationship between the permeability of the solute and that of water. If a solute permeates by dissolution in the membrane, sigma i = 1.0; if it permeates by passage through an aqueous channel, sigma i < 1.0. For urea, Goldstein and Solomon (1960) found that sigma urea = 0.62 +/- 0.03 which meant that urea crosses the red cell membrane in a water-filled channel. This result and many subsequent observations that showed that sigma urea < 1.0 are at variance with the observation that CHIP28 is impermeable to urea. In view of this problem, we have made a new series of measurements of sigma i for urea and other small solutes by a different method, which obviates many of the criticisms Macey and Karan (1993) have made of our earlier method. The new method (Chen et al., 1988), which relies upon fluorescence of the intracellular dye, fluorescein sulfonate, leads to the corrected value, sigma urea,corr = 0.64 +/- 0.03 for ghosts, in good agreement with earlier data for red cells. Thus, the conclusion on irreversible thermodynamic and other grounds that urea and water share a common channel is in disagreement with the view that CHIP28 provides the sole channel for water entrance into the cell. PMID:8703203

  7. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    PubMed Central

    Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects. PMID:24614613

  8. Equilibrium physics breakdown reveals the active nature of red blood cell flickering

    NASA Astrophysics Data System (ADS)

    Turlier, Herve; Fedosov, Dmitry; Auth, Thorsten; Gov, Nir S.; Sykes, Cecile; Joanny, Jean-Francois; Gompper, Gerhard; Betz, Timo

    2015-03-01

    Red blood cell membrane flickering stimulated an abundant biological, biophysical and biochemical literature over the past 50 years. While the phenomenon has been interpreted as thermal fluctuations of the cell membrane, recent results suggest the involvement of metabolic processes. However, to date there is no direct and conclusive evidence that an active force drives membrane flickering. By comparing membrane undulations and active microrheology measurements on single human erythrocytes, we show that flickering is partly driven by an active metabolic process, as it does not satisfy the equilibrium fluctuation-dissipation relation on timescales slower than 100ms. Analytical and numerical models of the red blood cell reproduce experimental results. The analytical model assumes that membrane activity results from reversible binding of the elastic spectrin network to the lipid bilayer and predicts active fluctuations to increase with local curvature and extensional prestress in the cytoskeleton. Our mean-field calculation shows that the strength and kinetics of the binding activity regulates thereupon both passive and active mechanical properties of the red blood cell. Numerical simulations explore other possible origins of active forces on the membrane and predict coherent timescales for the molecular underlying metabolic processes.

  9. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows

    NASA Astrophysics Data System (ADS)

    Brust, M.; Aouane, O.; Thiébaud, M.; Flormann, D.; Verdier, C.; Kaestner, L.; Laschke, M. W.; Selmi, H.; Benyoussef, A.; Podgorski, T.; Coupier, G.; Misbah, C.; Wagner, C.

    2014-03-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects.

  10. The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows.

    PubMed

    Brust, M; Aouane, O; Thiébaud, M; Flormann, D; Verdier, C; Kaestner, L; Laschke, M W; Selmi, H; Benyoussef, A; Podgorski, T; Coupier, G; Misbah, C; Wagner, C

    2014-01-01

    The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects. PMID:24614613

  11. Early occurrence of red blood cell alloimmunization in patients with sickle cell disease.

    PubMed

    Sins, Joep W R; Biemond, Bart J; van den Bersselaar, Sil M; Heijboer, H; Rijneveld, Anita W; Cnossen, Marjon H; Kerkhoffs, Jean-Louis H; van Meurs, Alfred H; von Ronnen, F B; Zalpuri, Saurabh; de Rijke, Yolanda B; Ellen van der Schoot, C; de Haas, Masja; van der Bom, Johanna G; Fijnvandraat, Karin

    2016-08-01

    Red blood cell (RBC) alloimmunization is a major complication of transfusion therapy in sickle cell disease (SCD). Identification of high-risk patients is hampered by lack of studies that take the cumulative transfusion exposure into account. In this retrospective cohort study among previously non-transfused SCD patients in the Netherlands, we aimed to elucidate the association between the cumulative transfusion exposure, first alloimmunization and independent risk factors. A total of 245 patients received 11 952 RBC units. Alloimmunization occurred in 43 patients (18%), half of them formed their first alloantibody before the 8th unit. In patients with exposure to non-extended matched transfusions (ABO and RhD) the cumulative alloimmunization risk increased up to 35% after 60 transfused units. This was significantly higher compared to a general transfused population (HR 6.6, CI 4.2-10.6). Receiving the first transfusion after the age of 5 was an independent risk factor for alloimmunization (HR 2.3, CI 1.0-5.1). Incidental, episodic transfusions in comparison to chronic scheme transfusions (HR 2.3, CI 0.9-6.0), and exposure to non-extended matched units in comparison to extended matching (HR 2.0, CI 0.9-4.6) seemed to confer a higher alloimmunization risk. The majority of first alloantibodies are formed after minor transfusion exposure, substantiating suggestions of a responder phenotype in SCD and stressing the need for risk factor identification. In this study, older age at first transfusion, episodic transfusions and non-extended matched transfusions appeared to be risk factors for alloimmunization. Am. J. Hematol. 91:763-769, 2016. © 2016 Wiley Periodicals, Inc. PMID:27102719

  12. Alloimmunization is associated with older age of transfused red blood cells in sickle cell disease

    PubMed Central

    Desai, Payal C.; Deal, Allison M.; Pfaff, Emily R.; Qaqish, Bahjat; Hebden, Leyna M.; Park, Yara A.; Ataga, Kenneth I.

    2016-01-01

    Red blood cell (RBC) alloimmunization is a significant clinical complication of sickle cell disease (SCD). It can lead to difficulty with cross-matching for future transfusions and may sometimes trigger life-threatening delayed hemolytic transfusion reactions. We conducted a retrospective study to explore the association of clinical complications and age of RBC with alloimmunization in patients with SCD followed at a single institution from 2005 to 2012. One hundred and sixty six patients with a total of 488 RBC transfusions were evaluated. Nineteen patients (11%) developed new alloantibodies following blood transfusions during the period of review. The median age of RBC units was 20 days (interquartile range: 14–27 days). RBC antibody formation was significantly associated with the age of RBC units (P = 0.002), with a hazard ratio of 3.5 (95% CI: 1.71–7.11) for a RBC unit that was 7 days old and 9.8 (95% CI: 2.66–35.97) for a unit that was 35 days old, 28 days after the blood transfusion. No association was observed between RBC alloimmunization and acute vaso-occlusive complications. Although increased echocardiography-derived tricuspid regurgitant jet velocity (TRV) was associated with the presence of RBC alloantibodies (P = 0.02), TRV was not significantly associated with alloimmunization when adjusted for patient age and number of transfused RBC units. Our study suggests that RBC antibody formation is significantly associated with older age of RBCs at the time of transfusion. Prospective studies in patients with SCD are required to confirm this finding. PMID:25963831

  13. Cellular Interrogation: Exploiting Cell-to-Cell Variability to Discriminate Regulatory Mechanisms in Oscillatory Signalling

    PubMed Central

    Gibson, Daniel; Chang, Frederick; Gnad, Florian; Gunawardena, Jeremy

    2016-01-01

    The molecular complexity within a cell may be seen as an evolutionary response to the external complexity of the cell’s environment. This suggests that the external environment may be harnessed to interrogate the cell’s internal molecular architecture. Cells, however, are not only nonlinear and non-stationary, but also exhibit heterogeneous responses within a clonal, isogenic population. In effect, each cell undertakes its own experiment. Here, we develop a method of cellular interrogation using programmable microfluidic devices which exploits the additional information present in cell-to-cell variation, without requiring model parameters to be fitted to data. We focussed on Ca2+ signalling in response to hormone stimulation, which exhibits oscillatory spiking in many cell types and chose eight models of Ca2+ signalling networks which exhibit similar behaviour in simulation. We developed a nonlinear frequency analysis for non-stationary responses, which could classify models into groups under parameter variation, but found that this question alone was unable to distinguish critical feedback loops. We further developed a nonlinear amplitude analysis and found that the combination of both questions ruled out six of the models as inconsistent with the experimentally-observed dynamics and heterogeneity. The two models that survived the double interrogation were mathematically different but schematically identical and yielded the same unexpected predictions that we confirmed experimentally. Further analysis showed that subtle mathematical details can markedly influence non-stationary responses under parameter variation, emphasising the difficulty of finding a “correct” model. By developing questions for the pathway being studied, and designing more versatile microfluidics, cellular interrogation holds promise as a systematic strategy that can complement direct intervention by genetics or pharmacology. PMID:27367445

  14. Cerebral blood flow and red cell delivery in normal subjects and in multiple sclerosis

    SciTech Connect

    Swank, R.L.; Roth, J.G.; Woody, D.C. Jr.

    1983-01-01

    Regional cerebral blood flow (rCBF) was determined in 77 normal females and 53 normal males of different ages and in 26 men and 45 women with multiple sclerosis by the inhalation of radioactive Xe133 method. In the normal subjects the CBF was relatively high in the teens and fell, at first rapidly and then slowly in both sexes with age. During adult life the flow in females was significantly higher than in males. The delivery of packed red cells (RCD) was determined by multiplying the CBF by the percentage concentration of red cells (HCT). The RCD for both sexes was nearly the same. In the patients with multiple sclerosis there occurred a progressive generalized decrease in CBF and in RCD with age which was significantly greater than observed in normal subjects. The rate of decrease in CBF and RCD correlated directly with the rate of progress of the disease.

  15. An improved automated method for the measurement of red cell 2,3-diphosphoglycerate.

    PubMed Central

    Purcell, Y; Brozović, B

    1976-01-01

    A modified automated colorimetric micromethod for the determination of red cell 2,3-diphosphoglycerate (2,3-DPG) adapted from that of Grisolia et al (1969) is described. In the modified method, ethylenediaminetetra-acetic acid (EDTA) is not used and consequently concentrations of several reagents are changed. During the development of the method it was found that the presence of EDTA, either in the blood or in reagents, consistently reduced the measured value of 2,3-DPG by 15%. This effect of EDTA, not previously recognized, is independent of the EDTA concentration within the range of 5 to 50 mmol/1 and is at present unexplianed. In normal subjects (41 men and 30 women) the mean red cell 2,3-DPG was 14-5 mol/g haemoglobin (range 12-1-18-1 mol/g haemoglobin). There was no significant difference in 2,3-DPG concentrations between male and female subjects. PMID:827552

  16. Self-Monitoring Artificial Red Cells with Sufficient Oxygen Supply for Enhanced Photodynamic Therapy

    NASA Astrophysics Data System (ADS)

    Luo, Zhenyu; Zheng, Mingbin; Zhao, Pengfei; Chen, Ze; Siu, Fungming; Gong, Ping; Gao, Guanhui; Sheng, Zonghai; Zheng, Cuifang; Ma, Yifan; Cai, Lintao

    2016-03-01

    Photodynamic therapy has been increasingly applied in clinical cancer treatments. However, native hypoxic tumoural microenvironment and lacking oxygen supply are the major barriers hindering photodynamic reactions. To solve this problem, we have developed biomimetic artificial red cells by loading complexes of oxygen-carrier (hemoglobin) and photosensitizer (indocyanine green) for boosted photodynamic strategy. Such nanosystem provides a coupling structure with stable self-oxygen supply and acting as an ideal fluorescent/photoacoustic imaging probe, dynamically monitoring the nanoparticle biodistribution and the treatment of PDT. Upon exposure to near-infrared laser, the remote-triggered photosensitizer generates massive cytotoxic reactive oxygen species (ROS) with sufficient oxygen supply. Importantly, hemoglobin is simultaneously oxidized into the more active and resident ferryl-hemoglobin leading to persistent cytotoxicity. ROS and ferryl-hemoglobin synergistically trigger the oxidative damage of xenograft tumour resulting in complete suppression. The artificial red cells with self-monitoring and boosted photodynamic efficacy could serve as a versatile theranostic platform.

  17. Validation of a model for investigating red cell mass changes during weightlessness

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1976-01-01

    The model, both the conceptual model and simulation model, provided a convenient framework on which to demonstrate the commonality between such diverse stresses as descent from altitude, red cell infusions, bed rest, and weightlessness. The results suggest that all of these stresses induce an increased blood hematocrit leading to tissue hyperoxia and eventual inhibition of the erythyocyte producing circuit until the hyperoxic condition is relieved. The erythropoietic system was acting, in these situations, as if it were an hematocrit sensor and regulator. In these terms the decreases in red cell mass during Skylab may be explained in terms of normal feedback regulation of the erythropoietic system in the face of sustained decreases in plasma colume.

  18. Delayed cord clamping in red blood cell alloimmunization: safe, effective, and free?

    PubMed Central

    2016-01-01

    Hemolytic disease of the newborn (HDN), an alloimmune disorder due to maternal and fetal blood type incompatibility, is associated with fetal and neonatal complications related to red blood cell (RBC) hemolysis. After delivery, without placental clearance, neonatal hyperbilirubinemia may develop from ongoing maternal antibody-mediated RBC hemolysis. In cases refractory to intensive phototherapy treatment, exchange transfusions (ET) may be performed to prevent central nervous system damage by reducing circulating bilirubin levels and to replace antibody-coated red blood cells with antigen-negative RBCs. The risks and costs of treating HDN are significant, but appear to be decreased by delayed umbilical cord clamping at birth, a strategy that promotes placental transfusion to the newborn. Compared to immediate cord clamping (ICC), safe and beneficial short-term outcomes have been demonstrated in preterm and term neonates receiving delayed cord clamping (DCC), a practice that may potentially be effective in cases RBC alloimmunization. PMID:27186530

  19. Use of remote blood releasing system for red cell transfusion in hospice care center

    PubMed Central

    Chan, Kwok Ying; Leung, Rock Yuk Yan; Cheung, Ka Chi; Lam, Clarence; Koo, Eleanor; Ng, Sylvia

    2016-01-01

    Objectives: It is quite common to have advanced cancer or end-stage renal disease patients for regular or even frequent blood transfusion in palliative care. However, due to geographical reason in some hospice centers, blood transfusion is sometimes difficult if blood bank is closed during non-office hour or not available. Methods: Here, we reported a new blood releasing system, that is, remote blood releasing system, that could be used safely by nursing staff alone when the blood bank was closed during the night time and holiday. Results: On-call nursing staff could collect red cells successful in these two cases. Conclusion: The new blood releasing system seems useful. However, larger sample sizes and longer period of study are required to estimate its efficacy and safety. The provision of antibody-positive red cells and platelet remained a limitation of this system. PMID:27489720

  20. Experiment on aggregation of red cells under microgravity on STS 51-C

    NASA Astrophysics Data System (ADS)

    Dintenfass, L.; Osman, P.; Maguire, B.; Jedrzejczyk, H.

    Kinetics and morphology of aggregation of red cells were studied using automatic slit-capillary photo-viscometers, one situated on the middeck of the space shuttle `Discovery', and the other in the ground laboratory at KSC. Experiments were run simultaneously, blood samples being adjusted to haematocrit of 0.30 using native plasma, at temp. of 25°C, and anticoagulated by EDTA. Donors included patients with myocardial infarction, insulin-dependent diabetes, hyperlipidaemia and hypertension. Macro and microphotographs were obtained during flow and statis. There was a striking difference in the morphology of aggregates formed in space and on the ground. Aggregates formed under zero gravity showed rouleaux formation, while the same blood samples showed severe clumping on the ground, in all patients blood. Normal blood showed rouleaux on the ground, but a random swarm-like pattern in space. The shape of the red cells remained normal under zero gravity.