WorldWideScience

Sample records for blood platelets

  1. Image analysis of blood platelets adhesion.

    Science.gov (United States)

    Krízová, P; Rysavá, J; Vanícková, M; Cieslar, P; Dyr, J E

    2003-01-01

    Adhesion of blood platelets is one of the major events in haemostatic and thrombotic processes. We studied adhesion of blood platelets on fibrinogen and fibrin dimer sorbed on solid support material (glass, polystyrene). Adhesion was carried on under static and dynamic conditions and measured as percentage of the surface covered with platelets. Within a range of platelet counts in normal and in thrombocytopenic blood we observed a very significant decrease in platelet adhesion on fibrin dimer with bounded active thrombin with decreasing platelet count. Our results show the imperative use of platelet poor blood preparations as control samples in experiments with thrombocytopenic blood. Experiments carried on adhesive surfaces sorbed on polystyrene showed lower relative inaccuracy than on glass. Markedly different behaviour of platelets adhered on the same adhesive surface, which differed only in support material (glass or polystyrene) suggest that adhesion and mainly spreading of platelets depends on physical quality of the surface. While on polystyrene there were no significant differences between fibrin dimer and fibrinogen, adhesion measured on glass support material markedly differed between fibrin dimer and fibrinogen. We compared two methods of thresholding in image analysis of adhered platelets. Results obtained by image analysis of spreaded platelets showed higher relative inaccuracy than results obtained by image analysis of platelets centres and aggregates.

  2. Mapuche Herbal Medicine Inhibits Blood Platelet Aggregation

    Directory of Open Access Journals (Sweden)

    Susan Skanderup Falkenberg

    2012-01-01

    Full Text Available 12 plant species traditionally used by the Mapuche people in Chile to treat wounds and inflammations have been evaluated for their direct blood platelet inhibition. Seven of the 12 tested plant species showed platelet inhibitory effect in sheep blood, and four of these were also able to inhibit the ADP- (5.0 μM and collagen- (2.0 μg/mL induced aggregations in human blood. These four species in respective extracts (in brackets were Blechnum chilense (MeOH, Luma apiculata (H2O, Amomyrtus luma (DCM : MeOH 1 : 1 and Cestrum parqui (DCM : MeOH 1 : 1. The platelet aggregating inhibitory effects of A. luma (DCM : MeOH 1 : 1, and L. apiculata (H2O were substantial and confirmed by inhibition of platelet surface activation markers.

  3. Platelets

    Science.gov (United States)

    ... tiny fraction of the blood volume. The principal function of platelets is to prevent bleeding. Red blood cells are ... forming a long string. This illustrates the basic function of platelets, to stick to any foreign surface and then ...

  4. Platelet dynamics in three-dimensional simulation of whole blood.

    Science.gov (United States)

    Vahidkhah, Koohyar; Diamond, Scott L; Bagchi, Prosenjit

    2014-06-03

    A high-fidelity computational model using a 3D immersed boundary method is used to study platelet dynamics in whole blood. We focus on the 3D effects of the platelet-red blood cell (RBC) interaction on platelet margination and near-wall dynamics in a shear flow. We find that the RBC distribution in whole blood becomes naturally anisotropic and creates local clusters and cavities. A platelet can enter a cavity and use it as an express lane for a fast margination toward the wall. Once near the wall, the 3D nature of the platelet-RBC interaction results in a significant platelet movement in the transverse (vorticity) direction and leads to anisotropic platelet diffusion within the RBC-depleted zone or cell-free layer (CFL). We find that the anisotropy in platelet motion further leads to the formation of platelet clusters, even in the absence of any platelet-platelet adhesion. The transverse motion, and the size and number of the platelet clusters are observed to increase with decreasing CFL thickness. The 3D nature of the platelet-RBC collision also induces fluctuations in off-shear plane orientation and, hence, a rotational diffusion of the platelets. Although most marginated platelets are observed to tumble just outside the RBC-rich zone, platelets further inside the CFL are observed to flow with an intermittent dynamics that alters between sliding and tumbling, as a result of the off-shear plane rotational diffusion, bringing them even closer to the wall. To our knowledge, these new findings are based on the fundamentally 3D nature of the platelet-RBC interaction, and they underscore the importance of using cellular-scale 3D models of whole blood to understand platelet margination and near-wall platelet dynamics.

  5. The synthesis of proteins in unnucleated blood platelets

    OpenAIRE

    Michał Bijak; Joanna Saluk; Michał Błażej Ponczek Ponczek; Paweł Nowak; Barbara Wachowicz

    2013-01-01

    Platelets are the smallest, unnucleated blood cells that play a key role in maintaining normal hemostasis. In the human body about 1x1011 platelets are formed every day, as a the result of complex processes of differentiation, maturation and fragmentation of megakaryocytes. Studies done over 4 decades ago demonstrated that circulating in blood mature platelets can synthesize proteins. Recent discoveries confirm protein synthesis by unnucleated platelets in response to activation. Moreover, pr...

  6. Platelet concentrates, from whole blood or collected by apheresis?

    Science.gov (United States)

    van der Meer, Pieter F

    2013-04-01

    Platelet concentrates can be isolated from donated whole blood with the platelet-rich plasma-method or the buffy coat-method. Alternatively, platelets can be obtained by apheresis, harvesting the platelets but returning all other cells to the donor. The quality and characteristics of platelets during storage are affected by a number of factors, such as anticoagulant, centrifugation and processing after collection, and pre- or post storage pooling, but when comparing literature on the various methods, most differences balance out. To have sufficient platelets to treat an adult patient, whole-blood-derived platelet concentrates need pooling of multiple donations, thereby increasing the risk of infectious agent transmission at least two-fold as compared with apheresis units. Allo immunization rates, acute reaction rates, and transfusion related acute lung injury rates are not different. Apheresis donation procedures have fewer adverse events. All these factors need to be considered and weighed when selecting a method of platelet collection for a blood center.

  7. The effects of selective serotonin reuptake inhibitors on platelet function in whole blood and platelet concentrates.

    Science.gov (United States)

    Reikvam, Anne-Grete; Hustad, Steinar; Reikvam, Håkon; Apelseth, Torunn Oveland; Nepstad, Ina; Hervig, Tor Audun

    2012-01-01

    Several studies report that patients who are treated with selective serotonin reuptake inhibitors (SSRIs) for depression may have increased risk of bleeding, particularly from the gastrointestinal tract. This may be related to low intraplatelet serotonin concentrations. Several blood banks do not store platelets from donors using SSRIs for transfusion, although the possible effects of SSRIs on platelet storage are not documented. We conducted a case-control pilot study of apheresis platelet concentrates prepared from donors using SSRIs (n=8) and from donors without medication (n=10). The platelet concentrates were stored for 5 days. Light transmission aggregometry (LTA), thrombelastography (TEG), and flow cytometric analyses were preformed for in vitro measurements of platelet function. Platelet function and platelet serotonin content were investigated in whole blood and in platelet concentrates stored for up to 5 days. LTA, TEG, and flow cytometric analysis of glycoprotein expression did not reveal any significant differences between the two groups. All 18 platelet concentrates performed well according to the standards set for platelet quality in relation to transfusion. Blood donors using SSRIs had significantly lower platelet serotonin compared to blood donors without medication. The results from our pilot study indicate that platelets from donors using SSRIs may be suitable for transfusion after storage for 5 days, but further laboratory and clinical studies are necessary to confirm this.

  8. Plasma functionalization of titanium surface for repulsion of blood platelets

    OpenAIRE

    Cvelbar, Uros; Modic, Martina; Kovac, J.; Lazovic, S; Filipic, G; Vujosevic, D; Junkar, Ita; Elersic, Kristina; Brühl, S.P.; Canal Barnils, Cristina; Belmonte, Thierry; Mozetic, Miran

    2012-01-01

    Thrombosis and restenosis are the most common problems during insertion of biocompatible implants like titanium stents into human blood, due to aggregation of platelets on their surfaces. Because of this reason, we studied the response of blood platelets to a plasma treated titanium surface. The aim was to design a functionalized surface which would repel blood platelets or prevent their adhesion. Therefore, we functionalized surfaces with low-temperature inductively coupled oxygen plasma tre...

  9. Platelet aggregation and quality control of platelet concentrates produced in the Amazon Blood Bank

    Directory of Open Access Journals (Sweden)

    Maria José Dantas Coêlho

    2011-01-01

    Full Text Available BACKGROUND: The study of platelet aggregation is essential to assess in vitro platelet function by different platelet activation pathways. OBJECTIVE: To assess aggregation and biochemical parameters of random platelet concentrates produced at the Fundação HEMOAM using the quality control tests defined by law. METHODS: Whole blood samples from 80 donors and the respective platelet concentrate units were tested. Platelet concentrates were tested (platelet count, aggregation and pH on days 1, 3 and 5 of storage. Additionally a leukocyte count was done only on day 1 and microbiological tests on day 5 of storage. Collagen and adenosine diphosphate were used as inducing agonists for platelet aggregation testing. RESULTS: Donor whole blood had normal aggregation (aggregation with adenosine diphosphate = 67% and with collagen = 78%. The median aggregation in platelet concentrates with adenosine diphosphate was low throughout storage (18% on day 1, 7% on day 3 and 6% on day 5 and the median aggregation with collagen was normal only on day 1 and low thereafter (54.4% on day 1, 20.5% on day 3 and 9% on day 5. CONCLUSION: Although the results were within the norms required by law, platelet concentrates had low aggregation rates. We suggest the inclusion of a functional assessment test for the quality control of platelet concentrates for a more effective response to platelet replacement therapy.

  10. Platelet Dynamics in Three-Dimensional Simulation of Whole Blood

    OpenAIRE

    Vahidkhah, Koohyar; Diamond, Scott L.; Bagchi, Prosenjit

    2014-01-01

    A high-fidelity computational model using a 3D immersed boundary method is used to study platelet dynamics in whole blood. We focus on the 3D effects of the platelet-red blood cell (RBC) interaction on platelet margination and near-wall dynamics in a shear flow. We find that the RBC distribution in whole blood becomes naturally anisotropic and creates local clusters and cavities. A platelet can enter a cavity and use it as an express lane for a fast margination toward the wall. Once near the ...

  11. [The synthesis of proteins in unnucleated blood platelets].

    Science.gov (United States)

    Bijak, Michał; Saluk, Joanna; Ponczek, Michał Błażej Ponczek; Nowak, Paweł; Wachowicz, Barbara

    2013-07-23

    Platelets are the smallest, unnucleated blood cells that play a key role in maintaining normal hemostasis. In the human body about 1x1011 platelets are formed every day, as a the result of complex processes of differentiation, maturation and fragmentation of megakaryocytes. Studies done over 4 decades ago demonstrated that circulating in blood mature platelets can synthesize proteins. Recent discoveries confirm protein synthesis by unnucleated platelets in response to activation. Moreover, protein synthesis alters the phenotype and function of platelets. Platelets synthesize several proteins involved in hemostasis (COX, αIIbβ3, TF PAI-1, Factor XI, protein C inhibitor) and in inflammatory process (IL-1β, CCL5/RANTES). In spite of lack of transcription platelets have a stable mRNA transcripts with a long life correlated with platelet life span. Platelets also show expression of two important key regulators of translation eIF4E and EIF-2α and have a variety of miRNA molecules responsible for translational regulation. This article describes the historical overview of research on protein synthesis by platelets and presents the molecular mechanisms of protein synthesis in activated platelets (and synthesis of the most important platelet proteins).

  12. Does bipolar pacemaker current activate blood platelets?

    DEFF Research Database (Denmark)

    Gjesdal, Grunde; Hansen, Annebirthe Bo; Brandes, Axel

    2009-01-01

    to the pacemaker can. METHODS: Platelet-rich plasma was prepared from two healthy subjects. Platelet reactivity to the agonist ADP was tested in paired samples in an aggregometer in a case/control setup. RESULTS: Eighteen of 46 tested pairs of platelet-rich plasma showed increased reactivity in the paced sample...

  13. Comparison of Platelet Transfusion as Fresh Whole Blood Versus Apheresis Platelets for Massively Transfused Combat Trauma patients

    Science.gov (United States)

    2011-02-01

    T R A N S F U S I O N P R A C T I C E Comparison of platelet transfusion as fresh whole blood versus apheresis platelets for massively transfused...is able to provide blood products to include apheresis platelets (aPLT), but also has extensive experience using fresh whole blood (FWB). In massively...bleeding, resuscitation with blood products is an ABBREVIATIONS: AIS(s) = Abbreviated Injury Scale(s); aPLT = apheresis platelets; ARDS = adult

  14. Namibia's transition from whole blood-derived pooled platelets to single-donor apheresis platelet collections

    NARCIS (Netherlands)

    Pitman, John P.; Basavaraju, Sridhar V.; Shiraishi, Ray W.; Wilkinson, Robert; von Finckenstein, Bjorn; Lowrance, David W.; Marfin, Anthony A.; Postma, Maarten; Mataranyika, Mary; Smit Sibinga, Cees Th.

    2015-01-01

    BACKGROUNDFew African countries separate blood donations into components; however, demand for platelets (PLTs) is increasing as regional capacity to treat causes of thrombocytopenia, including chemotherapy, increases. Namibia introduced single-donor apheresis PLT collections in 2007 to increase PLT

  15. Modifications of blood platelet proteins of patients with schizophrenia.

    Science.gov (United States)

    Dietrich-Muszalska, Anna; Olas, Beata

    2009-03-01

    Oxidative damage to lipids in plasma, blood platelets and neurons in patients with schizophrenia was described. The aim of our present study was to evaluate oxidative/nitrative modifications of blood platelets proteins by measurement the level of biomarkers of oxidative stress such as carbonyl groups, thiol groups and 3-nitrotyrosine in proteins in patients with schizophrenia and compare with a control group. Levels of carbonyl groups and 3-nitrotyrosine residues in platelet proteins were measured by ELISA and competition ELISA, respectively. The method with 5,5'-dithio-bis(2-nitro-benzoic acid) has been used to analyse thiol groups in platelet proteins. We demonstrated for the first time in platelet proteins from patients with schizophrenia a statistically significant increase of the level of biomarkers of oxidative/nitrative stress such as carbonyl groups or 3-nitrotyrosine; in schizophrenic patients the amount of thiol groups in platelet proteins was lower than in platelets from healthy subjects. Our results strongly indicate that in patients with schizophrenia reactive oxygen species and reactive nitrogen species induce not only peroxidation of lipids, but also may stimulate oxidative/nitrative modifications of platelet proteins. The consequence of these modifications may be the alteration of platelet protein structure and function.

  16. Determinants of ABH expression on human blood platelets.

    Science.gov (United States)

    Cooling, Laura L W; Kelly, Kathleen; Barton, James; Hwang, Debbie; Koerner, Theodore A W; Olson, John D

    2005-04-15

    Platelets express ABH antigens, which can adversely effect platelet transfusion recovery and survival in ABH-incompatible recipients. To date, there has been no large, comprehensive study comparing specific donor factors with ABH expression on platelet membranes and glycoconjugates. We studied ABH expression in 166 group A apheresis platelet donors by flow cytometry, Western blotting, and thin layer chromatography relative to donor age, sex, A1/A2 subgroup, and Lewis phenotype. Overall, A antigen on platelet membranes, glycoproteins, and glycosphingolipids was linked to an A1 red blood cell (RBC) phenotype. Among A1 donors, platelet ABH varied significantly between donors (0%-87%). Intradonor variability, however, was minimal, suggesting that platelet ABH expression is a stable, donor-specific characteristic, with 5% of A1 donors typing as either ABH high- or low-expressers. Group A2 donors, in contrast, possessed a Bombay-like phenotype, lacking both A and H antigens. Unlike RBCs, ABH expression on platelets may be determined primarily by H-glycosyltransferase (FUT1) activity. Identification of A2 and A1 low expressers may increase the availability and selection of crossmatched and HLA-matched platelets. Platelets from group A2 may also be a superior product for patients undergoing A/O major mismatch allogeneic progenitor cell transplantation.

  17. Inhibition of uptake of adenosine into human blood platelets

    NARCIS (Netherlands)

    Lips, J.P.M.; Sixma, J.J.; Trieschnigg, A.C.

    1980-01-01

    Adenosine transport into human blood platelets is mediated by two independent systems with different affinities. Both systems transport only purine nucleosides and no pyrimidine nucleosides. In experiments with differently substituted purine nucleosides, purines and analogues, differences in carrier

  18. Role of reactive nitrogen species in blood platelet functions.

    Science.gov (United States)

    Olas, Beata; Wachowicz, Barbara

    2007-12-01

    Blood platelets, in analogy to other circulating blood cells, can generate reactive oxygen/nitrogen species (ROS/RNS) that may behave as second messengers and may regulate platelet functions. Accumulating evidence suggest a role of ROS/RNS in platelet activation. On the other hand, an increased production of ROS/RNS causes oxidative stress, and thus, may contribute to the development of different diseases, including vascular complications, inflammatory and psychiatric illnesses. Oxidative stress in platelets leads to chemical changes in a wide range of their components, and platelet proteins may be initial targets of ROS/RNS action. It has been demonstrated that reaction of proteins with ROS/RNS results in the oxidation and nitration of some amino acid residues, formation of aggregates or fragmentation of proteins. In oxidized proteins new carbonyl groups and protein hydroperoxides are also formed. In platelets, low molecular weight thiols such as glutathione (GSH), cysteine and cysteinylglycine and protein thiols may be also target for ROS/RNS action. This review describes the chemical structure and biological activities of reactive nitrogen species, mainly nitric oxide ((*)NO) and peroxynitrite (ONOO(-)) and their effects on blood platelet functions, and the mechanisms involved in their action on platelets.

  19. Role of blood platelets in infection and inflammation.

    Science.gov (United States)

    Klinger, Matthias H F; Jelkmann, Wolfgang

    2002-09-01

    Blood platelets are here presented as active players in antimicrobial host defense and the induction of inflammation and tissue repair in addition to their participation in hemostasis. Megakaryopoiesis is inhibited after acute infection with viruses or bacteria. In contrast, chronic inflammation is often associated with reactive thrombocytosis. Platelets can bind and internalize pathogens and release microbicidal proteins that kill certain bacteria and fungi. By making cell-cell contacts with leukocytes and endothelial cells, platelets assist white blood cells in rolling, arrest and transmigration. On stimulation by bacteria or thrombin, platelets release the content of their alpha-granules, which include an arsenal of bioactive peptides, such as CC-chemokines and CXC-chemokines and growth factors for endothelial cells, smooth muscle cells and fibroblasts. Thus, integral to innate immunity, the tiny little platelets may become bombshells when irritated by pathogens.

  20. Single-step separation of platelets from whole blood coupled with digital quantification by interfacial platelet cytometry (iPC).

    Science.gov (United States)

    Basabe-Desmonts, L; Ramstrom, S; Meade, G; O'Neill, S; Riaz, A; Lee, L P; Ricco, A J; Kenny, D

    2010-09-21

    We report the efficient single-step separation of individual platelets from unprocessed whole blood, enabling digital quantification of platelet function using interfacial platelet cytometry (iPC) on a chip. iPC is accomplished by the precision micropatterning of platelet-specific protein surfaces on solid substrates. By separating platelets from whole blood using specific binding to protein spots of a defined size, iPC implements a simple incubate-and-rinse approach, without sample preparation, that enables (1) the study of platelets in the physiological situation of interaction with a protein surface, (2) the choice of the number of platelets bound on each protein spot, from one to many, (3) control of the platelet-platelet distance, including the possibility to study noninteracting single platelets, (4) digital quantification (counting) of platelet adhesion to selected protein matrices, enabling statistical characterization of platelet subpopulations from meaningfully large numbers of single platelets, (5) the study of platelet receptor expression and spatial distribution, and (6) a detailed study of the morphology of isolated single platelets at activation levels that can be manipulated. To date, we have demonstrated 1-4 of the above list. Platelets were separated from whole blood using iPC with fibrinogen, von Willebrand factor (VWF), and anti-CD42b antibody printed "spots" ranging from a fraction of one to several platelet diameters (2-24 μm). The number of platelets captured per spot depends strongly on the protein matrix and the surface area of the spot, together with the platelet volume, morphology, and activation state. Blood samples from healthy donors, a May-Hegglin-anomaly patient, and a Glanzmann's Thrombasthenia patient were analyzed via iPC to confirm the specificity of the interaction between protein matrices and platelets. For example, the results indicate that platelets interact with fibrinogen spots only through the fibrinogen receptor (

  1. Physiopathology of blood platelets and development of platelet substitutes. Progress report, August 1, 1975--July 31, 1976

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, M G

    1976-04-28

    Progress is reported on studies on the physiology of blood platelets in thrombocytopenic patients and rabbits. Methods for the detection of platelet antibodies and the preservation of platelets in vitro were investigated. Studies on the effect of low doses of x irradiation (up to 1000 R) on platelet function indicate that platelets exposed to ionizing radiation have increased functional activity. A list is included of publications that report the results of the studies in detail.

  2. [The role of blood platelets in infections].

    Science.gov (United States)

    Micota, Bartłomiej; Sadowska, Beata; Różalska, Barbara

    2015-05-17

    Platelets are primarily associated with their main function, hemostasis, although it is known that these cells also exhibit biological activity in cancer progression, inflammation and infectious processes. During infection platelets, due to the expression of specific receptors - Toll-like receptors (TLRs) - which recognize molecular patterns associated with pathogens - pathogen-associated molecular patterns (PAMPs) - are activated by the presence of microorganism components and/or substances released from damaged cells/tissue. Further antimicrobial activity of platelets is based on their capacity for phagocytosis, generation of reactive oxygen species (ROS), and the synthesis, storage and release of proteins/peptides with antimicrobial activity. Another mechanism of platelet action is their immunomodulatory activity. It is based mainly on the ability to secrete chemotactic factors allowing the accumulation of professional immunocompetent cells at the site of infection, thus enhancing the effective eradication of an infectious agent. In chronic infections, platelets, due to release of numerous growth factors and various cytokines, support mechanisms of acquired immunity. They accelerate the maturation of dendritic cells, stimulate B cells to be immunoglobulin-producing plasma cells and potentiate the activity of T cells. Unfortunately, in certain situations (the existence of specific risk factors) the interaction of microorganisms with activated platelets may also be the cause of pathology within the cardiovascular system.

  3. Flow cytometric assessment of activation of peripheral blood platelets in dogs with normal platelet count and asymptomatic thrombocytopenia.

    Science.gov (United States)

    Żmigrodzka, M; Guzera, M; Winnicka, A

    2016-01-01

    Platelets play a crucial role in hemostasis. Their activation has not yet been evaluated in healthy dogs with a normal and low platelet count. The aim of this study was to determine the influence of activators on platelet activation in dogs with a normal platelet count and asymptomatic thrombocytopenia. 72 clinically healthy dogs were enrolled. Patients were allocated into three groups. Group 1 consisted of 30 dogs with a normal platelet count, group 2 included 22 dogs with a platelet count between 100 and 200×109/l and group 3 consisted of 20 dogs with a platelet count lower than 100×109/l. Platelet rich-plasma (PRP) was obtained from peripheral blood samples using tripotassium ethylenediaminetetraacetic acid (K3-EDTA) as anticoagulant. Next, platelets were stimulated using phorbol-12-myristate-13-acetate or thrombin, stabilized using procaine or left unstimulated. The expression of CD51 and CD41/CD61 was evaluated. Co-expression of CD41/CD61 and Annexin V served as a marker of platelet activation. The expression of CD41/CD61 and CD51 did not differ between the 3 groups. Thrombin-stimulated platelets had a significantly higher activity in dogs with a normal platelet count than in dogs with asymptomatic thrombocytopenia. Procaine inhibited platelet activity in all groups. In conclusion, activation of platelets of healthy dogs in vitro varied depending on the platelet count and platelet activator.

  4. Blood flow simulation on a role for red blood cells in platelet adhesion

    Science.gov (United States)

    Shimizu, Kazuya; Sugiyama, Kazuyasu; Takagi, Shu

    2016-11-01

    Large-scale blood flow simulations were conducted and a role for red blood cells in platelet adhesion was discussed. The flow conditions and hematocrit values were set to the same as corresponding experiments, and the numerical results were compared with the measurements. Numerical results show the number of platelets adhered on the wall is increased with the increase in hematocrit values. The number of adhered platelets estimated from the simulation was approximately 28 (per 0.01 square millimeter per minute) for the hematocrit value of 20%. These results agree well with the experimental results qualitatively and quantitatively, which proves the validity of the present numerical model including the interaction between fluid and many elastic bodies and the modeling of platelet adhesion. Numerical simulation also reproduces the behavior of red blood cells in the blood flow and their role in platelet adhesion. Red blood cells deform to a flat shape and move towards channel center region. In contrast, platelets are pushed out and have many chances to contact with the wall. As a result, the large number of adhered platelets is observed as hematocrit values becomes high. This result indicates the presence of red blood cells plays a crucial role in platelet adhesion.

  5. Influence of caffeine on blood pressure and platelet aggregation

    Directory of Open Access Journals (Sweden)

    José Wilson S. Cavalcante

    2000-08-01

    Full Text Available OBJECTIVE: Studies have demonstrated that methylxanthines, such as caffeine, are A1 and A2 adenosine receptor antagonists found in the brain, heart, lungs, peripheral vessels, and platelets. Considering the high consumption of products with caffeine in their composition, in Brazil and throughout the rest of the world, the authors proposed to observe the effects of this substance on blood pressure and platelet aggregation. METHODS: Thirteen young adults, ranging from 21 to 27 years of age, participated in this study. Each individual took 750mg/day of caffeine (250mg tid, over a period of seven days. The effects on blood pressure were analyzed through the pressor test with handgrip, and platelet aggregation was analyzed using adenosine diphosphate, collagen, and adrenaline. RESULTS: Diastolic pressure showed a significant increase 24 hours after the first intake (p<0.05. This effect, however, disappeared in the subsequent days. The platelet aggregation tests did not reveal statistically significant alterations, at any time during the study. CONCLUSION: The data suggest that caffeine increases diastolic blood pressure at the beginning of caffeine intake. This hypertensive effect disappears with chronic use. The absence of alterations in platelet aggregation indicates the need for larger randomized studies.

  6. Adjusting MtDNA Quantification in Whole Blood for Peripheral Blood Platelet and Leukocyte Counts

    Science.gov (United States)

    Gonzalez-Lazaro, Monica; Moreno-Loshuertos, Raquel; Fernandez-Silva, Patricio; Enriquez, Jose Antonio; Laclaustra, Martin

    2016-01-01

    Alterations of mitochondrial DNA copy number (mtDNAcn) in the blood (mitochondrial to nuclear DNA ratio) appear associated with several systemic diseases, including primary mitochondrial disorders, carcinogenesis, and hematologic diseases. Measuring mtDNAcn in DNA extracted from whole blood (WB) instead of from peripheral blood mononuclear cells or buffy coat may yield different results due to mitochondrial DNA present in platelets. The aim of this work is to quantify the contribution of platelets to mtDNAcn in whole blood [mtDNAcn(WB)] and to propose a correction formula to estimate leukocytes' mtDNAcn [mtDNAcn(L)] from mtDNAcn(WB). Blood samples from 10 healthy adults were combined with platelet-enriched plasma and saline solution to produce artificial blood preparations. Aliquots of each sample were combined with five different platelet concentrations. In 46 of these blood preparations, mtDNAcn was measured by qPCR. MtDNAcn(WB) increased 1.07 (95%CI 0.86, 1.29; p<0.001) per 1000 platelets present in the preparation. We proved that leukocyte count should also be taken into account as mtDNAcn(WB) was inversely associated with leukocyte count; it increased 1.10 (95%CI 0.95, 1.25, p<0.001) per unit increase of the ratio between platelet and leukocyte counts. If hematological measurements are available, subtracting 1.10 the platelets/leukocyte ratio from mtDNAcn(WB) may serve as an estimation for mtDNAcn(L). Both platelet and leukocyte counts in the sample are important sources of variation if comparing mtDNAcn among groups of patients when mtDNAcn is measured in DNA extracted from whole blood. Not taking the platelet/leukocyte ratio into account in whole blood measurements, may lead to overestimation and misclassification if interpreted as leukocytes' mtDNAcn. PMID:27736919

  7. Effects of Antimalarial Tafenoquine on Blood Platelet Activity and Survival

    Directory of Open Access Journals (Sweden)

    Hang Cao

    2017-01-01

    Full Text Available Background/Aims: The 8-aminoquinoline tafenoquine has been shown to be effective against Plasmodia, Leishmania and Trypanosoma. The substance is at least in part effective by triggering apoptosis of the parasites. Moreover, tafenoquine has been shown to trigger eryptosis, the suicidal erythrocyte death characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. The effect of tafenoquine on eryptosis is in part due to stimulation of Ca2+ entry and oxidative stress. Ca2+ entry is a critical event in the activation of blood platelets by thrombin and collagen related peptide (CRP. The present study explored, whether tafenoquine influences Ca2+ entry, activation and apoptosis of blood platelets. Methods: Platelets isolated from wild-type mice were exposed for 30 minutes to tafenoquine (2.5 µg/ml without or with an additional treatment with thrombin (0.01 U/ml or CRP (2 µg/ml or 5 µg/ml. Flow cytometry was employed to estimate cytosolic Ca2+-activity ([Ca2+]i from Fluo-3 fluorescence, platelet degranulation from P-selectin abundance, integrin activation from αIIbβ3 integrin abundance, phosphatidylserine abundance from annexin-V-binding, relative platelet volume from forward scatter, reactive oxygen species (ROS from DCF fluorescence, caspase 3 activity with an active caspase-3 Staining kit, and aggregation utilizing staining with CD9-APC and CD9-PE. Results: Both, thrombin (0.01 U/ml and CRP (2 µg/ml or 5 µg/ml, significantly increased [Ca2+]i, P-selectin abundance, active αIIbβ3 integrin, and annexin-V-binding, and both significantly decreased platelet volume, activated caspase 3 and stimulated aggregation. Administration of tafenoquine (2.5 µg/ml, 30 min significantly decreased [Ca2+]i both, in the absence and presence of thrombin and CRP. Tafenoquine significantly blunted the effect of thrombin and CRP on [Ca2+]i, P-selectin abundance, and active αIIbβ3 integrin, but

  8. Evaluation of different sized blood sampling tubes for thromboelastometry, platelet function, and platelet count

    DEFF Research Database (Denmark)

    Andreasen, Jo Bønding; Pistor-Riebold, Thea Unger; Knudsen, Ingrid Hell;

    2014-01-01

    count remained stable using a 3.6 mL tube during the entire observation period of 120 min (p=0.74), but decreased significantly after 60 min when using tubes smaller than 3.6 mL (pblood sampling tubes. Therefore, 1.8 mL tubes should...... be preferred for RoTEM® analyses in order to minimise the volume of blood drawn. With regard to platelet aggregation analysed by impedance aggregometry tubes of different size cannot be used interchangeably. If platelet count is determined later than 10 min after blood sampling using tubes containing citrate......Background: To minimise the volume of blood used for diagnostic procedures, especially in children, we investigated whether the size of sample tubes affected whole blood coagulation analyses. Methods: We included 20 healthy individuals for rotational thromboelastometry (RoTEM®) analyses...

  9. Blood Platelet Production: Optimization by Dynamic Programming and Simulation

    NARCIS (Netherlands)

    Haijema, R.; Wal, van der J.; Dijk, van N.M.

    2007-01-01

    Blood platelets are precious, as voluntarily supplied by donors, and highly perishable, with limited lifetimes of 5¿7 days. Demand is highly variable and uncertain. A practical production and inventory rule is strived for that minimizes shortages and spill. The demand and production are periodic, as

  10. Stability of catecholamines in whole blood, plasma, and platelets.

    Science.gov (United States)

    Weir, T B; Smith, C C; Round, J M; Betteridge, D J

    1986-05-01

    Checking catecholamine stability in whole blood, plasma, and platelets, we found that specimens stored at room temperature or frozen for periods ranging from 1.5 h to three weeks show no significant difference in measured catecholamine concentration. The implications of these findings are discussed.

  11. Contribution of blood platelets to vascular pathology in Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Zhang W

    2013-11-01

    Full Text Available Wei Zhang,1,2 Wei Huang,1 Fang Jing11Department of Pharmacology, Institutes for Advanced Interdisciplinary Research, East China Normal University, Shanghai, People's Republic of China; 2Shanghai Engineering Research Center of Molecular Therapy and Pharmaceutical Innovation, Shanghai, People's Republic of ChinaAbstract: Cerebral amyloid angiopathy (CAA is a critical factor in the pathogenesis of Alzheimer's disease (AD. In the clinical setting, nearly 98% AD patients have CAA, and 75% of these patients are rated as severe CAA. It is characterized by the deposition of the β-amyloid peptide (mainly Aβ40 in the walls of cerebral vessels, which induces the degeneration of vessel wall components, reduces cerebral blood flow, and aggravates cognitive decline. Platelets are anuclear cell fragments from bone marrow megakaryocytes and their function in hemostasis and thrombosis has long been recognized. Recently, increasing evidence suggests that platelet activation can also mediate the onset and development of CAA. First, platelet activation and adhesion to a vessel wall is the initial step of vascular injury. Activated platelets contribute to more than 90% circulating Aß (mainly Aβ1-40, which in turn activates platelets and results in the vicious cycle of Aβ overproduction in damaged vessel. Second, the uncontrolled activation of platelets leads to a chronic inflammatory reaction by secretion of chemokines (eg, platelet factor 4 [PF4], regulated upon activation normal T-cell expressed and presumably secreted [RANTES], and macrophage inflammatory protein [MIP-1α], interleukins (IL-1 β, IL-7, and IL-8, prostaglandins, and CD40 ligand (CD40L. The interaction of these biological response modulators with platelets, endothelial cells, and leukocytes establishes a localized inflammatory response that contributes to CAA formation. Finally, activated platelets are the upholder of fibrin clots, which are structurally abnormal and resistant to degradation

  12. Effects of argon laser on in vitro aggregation of platelets in platelet rich plasma and whole blood

    Energy Technology Data Exchange (ETDEWEB)

    Doerger, P.T.; Glueck, H.I.; McGill, M.

    1988-06-01

    The effects of an Argon laser on platelet aggregation were studied, since platelets may be exposed to laser energy when used intravascularly. Various preparations of platelets in platelet rich plasma (PRP) and whole blood, with or without aspirin, were tested with the aggregating agents ADP, collagen, thrombin, and epinephrine. Simultaneous release of ATP was also measured in PRP. At relatively low levels of irradiation, platelet aggregation was potentiated. Enhancement was evidenced by an increase in percent aggregation, earlier onset of the reaction, and reduction in the amount of aggregating agent required. In PRP, the mechanism of laser potentiation appeared to be the release of endogenous ATP from platelets. At relatively high levels of irradiation, platelets were destroyed and aggregation abolished. In whole blood, the mechanism was somewhat more complicated since release of ATP occurred from RBCs as well as platelets. Spontaneous aggregation following laser treatment occurred in isolated instances in PRP and in every trial in whole blood preparations. Aspirin ingestion inhibited the laser's effects in PRP but not in whole blood. These results may have important clinical implications for laser angioplasty, and the potentiated aggregation response may prove useful in laboratory studies of platelet function.

  13. Blood mean platelet volume and platelet lymphocyte ratio as new predictors of hip osteoarthritis severity.

    Science.gov (United States)

    Taşoğlu, Özlem; Şahin, Ali; Karataş, Gülşah; Koyuncu, Engin; Taşoğlu, İrfan; Tecimel, Osman; Özgirgin, Neşe

    2017-02-01

    Osteoarthritis (OA) is a low grade systemic inflammatory disease in which many inflammatory mediators are known to be elevated in the peripheric blood. Blood platelet lymphocyte ratio (PLR) and mean platelet volume (MPV) are accepted as novel markers in many of the systemic inflammatory disorders, but have not been investigated in synovitis-free radiographic OA yet.The aim of this study was to evaluate the levels of blood PLR and MPV in radiographic hip OA. A total of 880 patients were evaluated retrospectively and after certain exclusion criteria, 237 of them who have primary hip OA were included. Age, sex, height, weight, body mass index, neutrophil, lymphocyte and platelet counts, erythrocyte sedimentation rate (ESR), PLR, and MPV levels were recorded, Kellgren-Lawrence (KL) grading of the hip joints were performed. Patients were then divided into 2 groups as KL grades 1 to 2 (mild-moderate) and KL grades 3 to 4 (severe) hip OA.Mean age, mean neutrophil, lymphocyte and platelet counts, mean MPV, mean PLR, and mean ESR were statistically significantly different between mild/moderate hip OA group and severe hip OA group. In univariate analysis, older age and higher MPV, PLR, and ESR were severely associated with severe hip OA. In multiple logistic regression analysis, MPV, PLR, and ESR emerged as independent predictors of severe hip OA.The results of the present study, for the first time in the literature, suggest blood PLR and MPV as novel inflammatory markers predicting the radiographic severity of hip OA in the daily practice.

  14. The Influence of Low Platelet Count on Whole Blood Aggregometry Assessed by Multiplate

    DEFF Research Database (Denmark)

    Stissing, Trine; Dridi, Nadia P; Ostrowski, Sisse R;

    2011-01-01

    The Multiplate, a whole blood (WB) platelet function test, has shown promising results identifying patients on antiplatelet therapy at increased risk of rethrombosis. In the present study, the influence of low platelet count on platelet aggregation was analyzed and compared with aggregation results...... in an artificial matrix, platelet-rich plasma (PRP). Heparinized and citrated blood was diluted with autologous plasma to platelet concentrations 200 to 25 × 10(9)/L in WB samples (n = 10) and 200 to 100 × 10(9)/L in PRP samples (n = 7). The platelet aggregation was investigated by the ADP-, ASPI-, COL-, and TRAP...

  15. Mesoscopic Modeling of Blood Clotting: Coagulation Cascade and Platelets Adhesion

    Science.gov (United States)

    Yazdani, Alireza; Li, Zhen; Karniadakis, George

    2015-11-01

    The process of clot formation and growth at a site on a blood vessel wall involve a number of multi-scale simultaneous processes including: multiple chemical reactions in the coagulation cascade, species transport and flow. To model these processes we have incorporated advection-diffusion-reaction (ADR) of multiple species into an extended version of Dissipative Particle Dynamics (DPD) method which is considered as a coarse-grained Molecular Dynamics method. At the continuum level this is equivalent to the Navier-Stokes equation plus one advection-diffusion equation for each specie. The chemistry of clot formation is now understood to be determined by mechanisms involving reactions among many species in dilute solution, where reaction rate constants and species diffusion coefficients in plasma are known. The role of blood particulates, i.e. red cells and platelets, in the clotting process is studied by including them separately and together in the simulations. An agonist-induced platelet activation mechanism is presented, while platelets adhesive dynamics based on a stochastic bond formation/dissociation process is included in the model.

  16. Mechanism of platelet activation induced by endocannabinoids in blood and plasma.

    Science.gov (United States)

    Brantl, S Annette; Khandoga, Anna L; Siess, Wolfgang

    2014-01-01

    Platelets play a central role in atherosclerosis and atherothrombosis, and circulating endocannabinoids might modulate platelet function. Previous studies concerning effects of anandamide (N-arachidonylethanolamide) and 2-arachidonoylglycerol (2-AG) on platelets, mainly performed on isolated cells, provided conflicting results. We therefore investigated the action of three main endocannabinoids [anandamide, 2-AG and virodhamine (arachidonoylethanolamine)] on human platelets in blood and platelet-rich plasma (PRP). 2-AG and virodhamine induced platelet aggregation in blood, and shape change, aggregation and adenosine triphosphate (ATP) secretion in PRP. The EC50 of 2-AG and virodhamine for platelet aggregation in blood was 97 and 160 µM, respectively. Lower concentrations of 2-AG (20 µM) and virodhamine (50 µM) synergistically induced aggregation with other platelet stimuli. Platelet activation induced by 2-AG and virodhamine resembled arachidonic acid (AA)-induced aggregation: shape change, the first platelet response, ATP secretion and aggregation induced by 2-AG and virodhamine were all blocked by acetylsalicylic acid (ASA) or the specific thromboxane A2 (TXA2) antagonist daltroban. In addition, platelet activation induced by 2-AG and virodhamine in blood and PRP were inhibited by JZL184, a selective inhibitor of monoacylglycerol lipase (MAGL). In contrast to 2-AG and virodhamine, anandamide, a substrate of fatty acid amidohydrolase, was inactive. Synthetic cannabinoid receptor subtype 1 (CB1) and 2 (CB2) agonists lacked stimulatory as well as inhibitory platelet activity. We conclude that 2-AG and virodhamine stimulate platelets in blood and PRP by a MAGL-triggered mechanism leading to free AA and its metabolism by platelet cyclooxygenase-1/thromboxane synthase to TXA2. CB1, CB2 or non-CB1/CB2 receptors are not involved. Our results imply that ASA and MAGL inhibitors will protect platelets from activation by high endocannabinoid levels, and that

  17. The influence of platelets, plasma and red blood cells on functional haemostatic assays.

    Science.gov (United States)

    Bochsen, Louise; Johansson, Pär I; Kristensen, Annemarie T; Daugaard, Gedske; Ostrowski, Sisse R

    2011-04-01

    Functional whole blood haemostatic assays are used increasingly to guide transfusion therapy and monitor medical treatment and are also applied for in-vitro evaluations of the haemostatic potential of stored platelets. We investigated how the cellular and plasmatic elements, both isolated and combined, influenced the two methodologically different assays, thrombelastography (TEG) and impedance aggregometry (Multiplate). Platelet-rich plasma (200 × 10/l) or pure plasma (0 platelets), with and without added red blood cells (RBCs), hematocrit 0, 0.15 or 0.29, were produced in vitro from platelet concentrates, fresh frozen plasma and stored RBC. Pure platelets were investigated by removing plasma components from platelet concentrates by diafiltration against the platelet storage solution Intersol. Plasma was readded by diafiltration against plasma in Intersol. Haemostatic function was evaluated by TEG and Multiplate. In the TEG, increasing amounts of RBC reduced clot strength and clot kinetics (α-angle), most markedly in plasma/RBC without platelets. In contrast, RBC in a platelet concentrate matrix enhanced Multiplate aggregation in response to weak agonists (ADP and arachidonic acid). Furthermore, removing plasma from platelet concentrates eliminated the TEG response and diminished the Multiplate aggregation response, but readding plasma to the pure platelet concentrates restored the response. Each of the elements in whole blood, plasma, platelets and RBC, affected the Multiplate and TEG results differently. The results emphasize that the concentrations of all cellular and plasmatic components in whole blood should be taken into account when interpreting results obtained by TEG and multiplate.

  18. The Influence of Low Platelet Count on Whole Blood Aggregometry Assessed by Multiplate

    DEFF Research Database (Denmark)

    Stissing, Trine; Dridi, Nadia P; Ostrowski, Sisse R

    2011-01-01

    in an artificial matrix, platelet-rich plasma (PRP). Heparinized and citrated blood was diluted with autologous plasma to platelet concentrations 200 to 25 × 10(9)/L in WB samples (n = 10) and 200 to 100 × 10(9)/L in PRP samples (n = 7). The platelet aggregation was investigated by the ADP-, ASPI-, COL-, and TRAP...

  19. Abnormal whole blood thrombi in humans with inherited platelet receptor defects.

    Directory of Open Access Journals (Sweden)

    Francis J Castellino

    Full Text Available To delineate the critical features of platelets required for formation and stability of thrombi, thromboelastography and platelet aggregation measurements were employed on whole blood of normal patients and of those with Bernard-Soulier Syndrome (BSS and Glanzmann's Thrombasthenia (GT. We found that separation of platelet activation, as assessed by platelet aggregation, from that needed to form viscoelastic stable whole blood thrombi, occurred. In normal human blood, ristocetin and collagen aggregated platelets, but did not induce strong viscoelastic thrombi. However, ADP, arachidonic acid, thrombin, and protease-activated-receptor-1 and -4 agonists, stimulated both processes. During this study, we identified the genetic basis of a very rare double heterozygous GP1b deficiency in a BSS patient, along with a new homozygous GP1b inactivating mutation in another BSS patient. In BSS whole blood, ADP responsiveness, as measured by thrombus strength, was diminished, while ADP-induced platelet aggregation was normal. Further, the platelets of 3 additional GT patients showed very weak whole blood platelet aggregation toward the above agonists and provided whole blood thrombi of very low viscoelastic strength. These results indicate that measurements of platelet counts and platelet aggregability do not necessarily correlate with generation of stable thrombi, a potentially significant feature in patient clinical outcomes.

  20. Abnormal whole blood thrombi in humans with inherited platelet receptor defects.

    Science.gov (United States)

    Castellino, Francis J; Liang, Zhong; Davis, Patrick K; Balsara, Rashna D; Musunuru, Harsha; Donahue, Deborah L; Smith, Denise L; Sandoval-Cooper, Mayra J; Ploplis, Victoria A; Walsh, Mark

    2012-01-01

    To delineate the critical features of platelets required for formation and stability of thrombi, thromboelastography and platelet aggregation measurements were employed on whole blood of normal patients and of those with Bernard-Soulier Syndrome (BSS) and Glanzmann's Thrombasthenia (GT). We found that separation of platelet activation, as assessed by platelet aggregation, from that needed to form viscoelastic stable whole blood thrombi, occurred. In normal human blood, ristocetin and collagen aggregated platelets, but did not induce strong viscoelastic thrombi. However, ADP, arachidonic acid, thrombin, and protease-activated-receptor-1 and -4 agonists, stimulated both processes. During this study, we identified the genetic basis of a very rare double heterozygous GP1b deficiency in a BSS patient, along with a new homozygous GP1b inactivating mutation in another BSS patient. In BSS whole blood, ADP responsiveness, as measured by thrombus strength, was diminished, while ADP-induced platelet aggregation was normal. Further, the platelets of 3 additional GT patients showed very weak whole blood platelet aggregation toward the above agonists and provided whole blood thrombi of very low viscoelastic strength. These results indicate that measurements of platelet counts and platelet aggregability do not necessarily correlate with generation of stable thrombi, a potentially significant feature in patient clinical outcomes.

  1. Fusaric acid, a mycotoxin, and its influence on blood coagulation and platelet function.

    Science.gov (United States)

    Devaraja, Sannaningaiah; Girish, Kesturu S; Santhosh, Martin S; Hemshekhar, Mahadevappa; Nayaka, Siddaiah C; Kemparaju, Kempaiah

    2013-06-01

    The current study intended to explore the effect of fusaric acid on blood coagulation including plasma coagulation and platelet aggregation. Fusaric acid exhibited biphasic effects on citrated human plasma recalcification time. At concentrations below 50 ng, fusaric acid decreased the clotting time of plasma dose-dependently from 130 ± 3s control value to 32 ± 3s; however, above 50 ng, fusaric acid increased the clotting time from 32 ± 3s and reached a maximum of 152 s at 100 ng and remained unaltered thereafter for the increased dose of fusaric acid. Fusaric acid without damaging red blood cells and platelets, inhibited agonists such as collagen, ADP, thrombin, and epinephrine-induced aggregation of both platelet-rich plasma (PRP) and washed platelets preparations of human. Interestingly, fusaric acid showed biphasic effects only in thrombin-induced platelet aggregation of washed platelets, and at lower concentration (below 900 ng) it activated platelet aggregation; however, in increased concentration (above 900 ng) it inhibited the platelet aggregation of washed platelets. In addition, fusaric acid also inhibited the agonist ADP-induced platelet aggregation of washed platelet suspension but did not show biphasic effect. Further, fusaric acid did not induce the platelets to generate reactive oxygen species (ROS) that clearly suggests that the induction of platelet function could be the result of the fusaric acid-mediated receptor interaction but not through the morphological shape change.

  2. Novel function for blood platelets and podoplanin in developmental separation of blood and lymphatic circulation.

    Science.gov (United States)

    Uhrin, Pavel; Zaujec, Jan; Breuss, Johannes M; Olcaydu, Damla; Chrenek, Peter; Stockinger, Hannes; Fuertbauer, Elke; Moser, Markus; Haiko, Paula; Fässler, Reinhard; Alitalo, Kari; Binder, Bernd R; Kerjaschki, Dontscho

    2010-05-13

    During embryonic development, lymph sacs form from the cardinal vein, and sprout centrifugally to form mature lymphatic networks. Separation of the lymphatic from the blood circulation by a hitherto unknown mechanism is essential for the homeostatic function of the lymphatic system. O-glycans on the lymphatic endothelium have recently been suggested to be required for establishment and maintenance of distinct blood and lymphatic systems, primarily by mediating proper function of podoplanin. Here, we show that this separation process critically involves platelet activation by podoplanin. We found that platelet aggregates build up in wild-type embryos at the separation zone of podoplanin(+) lymph sacs and cardinal veins, but not in podoplanin(-/-) embryos. Thus, podoplanin(-/-) mice develop a "nonseparation" phenotype, characterized by a blood-filled lymphatic network after approximately embryonic day 13.5, which, however, partially resolves in postnatal mice. The same embryonic phenotype is also induced by treatment of pregnant mice with acetyl salicylic acid, podoplanin-blocking antibodies, or by inactivation of the kindlin-3 gene required for platelet aggregation. Therefore, interaction of endothelial podoplanin of the developing lymph sac with circulating platelets from the cardinal vein is critical for separating the lymphatic from the blood vascular system.

  3. A whole blood model of thrombocytopenia that controls platelet count and hematocrit.

    Science.gov (United States)

    Bercovitz, R S; Brenner, M K; Newman, D K

    2016-10-01

    In patients with thrombocytopenia, it can be difficult to predict a patient's bleeding risk based on platelet count alone. Platelet reactivity may provide additional information; however, current clinical assays cannot reliably assess platelet function in the setting of thrombocytopenia. New methods to study platelet reactivity in thrombocytopenic samples are needed. In this study, we sought to develop a laboratory model of thrombocytopenia using blood from healthy subjects that preserves the whole blood environment and reproducibly produces samples with a specific platelet count and hematocrit. We compared the activation state of unstimulated and agonist-stimulated platelets in thrombocytopenic samples derived from this method with normocytic controls. Whole blood was diluted with autologous red blood cell concentrate and platelet-poor plasma, which were obtained via centrifugation, in specific ratios to attain a final sample with a predetermined platelet count and hematocrit. P-selectin exposure and GPIIbIIIa activation in unstimulated platelets and platelets stimulated with collagen-related peptide (CRP) or adenosine diphosphate (ADP) in thrombocytopenic samples and the normocytic control from which they were derived were quantified by flow cytometry. Our methodology reliably produced thrombocytopenic samples with a platelet count ≤50,000/μL and an accurately and precisely controlled hematocrit. P-selectin exposure and GPIIbIIIa activation on unstimulated platelets or on ADP- or CRP-stimulated platelets did not differ in thrombocytopenic samples compared to normocytic controls. We describe a new method for creating thrombocytopenic blood that can be used to better understand the contributions of platelet number and function to hemostasis.

  4. Platelet Function in Stored Heparinised Autologous Blood Is Not Superior to in Patient Platelet Function during Routine Cardiopulmonary Bypass

    NARCIS (Netherlands)

    Huet, Rolf C. G. Gallandat; de Vries, Adrianus J.; Cernak, Vladimir; Lisman, Ton

    2012-01-01

    Background: In cardiac surgery, cardiopulmonary bypass (CPB) and unfractionated heparin have negative effects on blood platelet function. In acute normovolemic haemodilution autologous unfractionated heparinised blood is stored ex-vivo and retransfused at the end of the procedure to reduce (allogene

  5. The influence of platelets, plasma and red blood cells on functional haemostatic assays

    DEFF Research Database (Denmark)

    Bochsen, Louise; Johansson, Pär I.; Kristensen, Annemarie Thuri

    2011-01-01

    and combined, influenced the two methodologically different assays, thrombelastography (TEG) and impedance aggregometry (Multiplate). Platelet-rich plasma (200 × 10/l) or pure plasma (0 platelets), with and without added red blood cells (RBCs), hematocrit 0, 0.15 or 0.29, were produced in vitro from platelet...... concentrates, fresh frozen plasma and stored RBC. Pure platelets were investigated by removing plasma components from platelet concentrates by diafiltration against the platelet storage solution Intersol. Plasma was readded by diafiltration against plasma in Intersol. Haemostatic function was evaluated by TEG...... and Multiplate. In the TEG, increasing amounts of RBC reduced clot strength and clot kinetics (α-angle), most markedly in plasma/RBC without platelets. In contrast, RBC in a platelet concentrate matrix enhanced Multiplate aggregation in response to weak agonists (ADP and arachidonic acid). Furthermore, removing...

  6. Alterations of adenine nucleotide metabolism and function of blood platelets in patients with diabetes.

    Science.gov (United States)

    Michno, Anna; Bielarczyk, Hanna; Pawełczyk, Tadeusz; Jankowska-Kulawy, Agnieszka; Klimaszewska, Joanna; Szutowicz, Andrzej

    2007-02-01

    Increased activity of blood platelets contributes to vascular complications in patients with diabetes. The aim of this work was to investigate whether persisting hyperglycemia in diabetic patients generates excessive accumulation of ATP/ADP, which may underlie platelet hyperactivity. Platelet ATP and ADP levels, thiobarbituric acid-reactive species synthesis, and aggregation of platelets from patients with diabetes were 18-82% higher than in platelets from healthy participants. In patients with diabetes, platelet stimulation with thrombin caused about two times greater release of ATP and ADP than in the healthy group while decreasing intraplatelet nucleotide content to similar levels in both groups. This indicates that the increased content of adenylate nucleotides in the releasable pool in the platelets of diabetic patients does not affect their level in metabolic cytoplasmic/mitochondrial compartments. Significant correlations between platelet ATP levels and plasma fructosamine, as well as between platelet ATP/ADP and platelet activities, have been found in diabetic patients. In conclusion, chronic hyperglycemia-evoked elevations of ATP/ADP levels and release from blood platelets of patients with diabetes may be important factors underlying platelet hyperactivity in the course of the disease.

  7. Low-power laser irradiation of blood inhibits platelet function: role of cyclic GMP

    Science.gov (United States)

    Brill, Alexander G.; Brill, Gregory E.; Shenkman, Boris; Tamarin, Ilya; Dardik, Rima; Varon, David; Savion, Naphtali

    1998-12-01

    The aim of the present work was to investigate effect of low power laser irradiation (LPLI) on platelet function in vitro. He-Ne laser (Optronix, USA; (lambda) - 632.8 nm, output power - 7 mW) was employed. Platelet adhesion and aggregation in whole blood (WB) under defined shear conditions were assayed by a Cone and Plate(let) Analyzer. Platelet activation was evaluated by flow cytometry. Level of platelet cGMP was estimated by immunoenzyme assay. Experiments performed showed that LPLI of WB resulted in decrease of platelet deposition on extracellular matrix at high shear rate (1300 s-1). Similar results were obtained using surfaces precoated with either collagen type I or von Willebrand factor. LPLI inhibited fibrinogen binding as well as P-selectin expression on the platelet membrane, induced by thrombin analogue. It was found out that primary acceptor of laser energy responsible for the effect on platelets was located in platelets themselves and not in blood plasma or in other blood cells. LPLI of gel- filtered platelets resulted in increase of intracellular level of cGMP both in the absence and in presence of izobutylmethylxantine (phosphodiesterase inhibitor) suggesting stimulation of synthesis rather than destruction of cGMP under the influence of LPLI. It is suggested that guanylate cyclase and/or NO-synthase might serve as primary acceptors of He-Ne laser light in platelets.

  8. Platelet-Rich Blood Derivatives for Stem Cell-Based Tissue Engineering and Regeneration

    NARCIS (Netherlands)

    Masoudi, E.A.; Ribas, J.; Kaushik, G.; Leijten, J.C.H.; Khademhosseini, A.

    2016-01-01

    Platelet-rich blood derivatives have been widely used in different fields of medicine and stem cell-based tissue engineering. They represent natural cocktails of autologous growth factors, which could provide an alternative for recombinant protein-based approaches. Platelet-rich blood derivatives, s

  9. Era of blood component therapy: time for mandatory pre-donation platelet count for maximizing donor safety and optimizing quality of platelets.

    Science.gov (United States)

    Das, Sudipta Sekhar; Zaman, R U; Biswas, Dipak

    2013-12-01

    Blood bank regulatory agencies including the Drug and Cosmetics Act (DCA) of India do not mandate a predonation platelet count in whole blood donation. Mandating such practice will definitely optimize the quality of random donor platelets (RDP) in terms of platelet yield and patient therapeutic benefit. We observed poor platelet yield in RDP concentrates prepared at our center with a significant number not meeting the DCA guideline of ≥ 4.5 × 10(10) per bag processed from 450 ml of whole blood. Therefore we planned this study to evaluate the pre-donation hematological values in our blood donor population and effect of these values on the quality of platelet concentrates. The prospective study included 221 blood donors eligible for donating 450 ml of whole blood (WB). Following the departmental standard operating procedure (SOP) RDPs were prepared using the 'Top & Bottom' quadruple bag system and automated component extractor. Quality of RDP was assessed as per departmental protocol. All results were recorded and subsequently transcribed to SPSS working sheet. A significant (pblood counts has been observed after WB donation. Mean donor Hb and platelets reduced by 0.72 g/dl and 22.1 × 10(6)/ml respectively. Quality of RDPs in terms of platelet yield was significantly better (pcount was >200 × 10(6)/ml. Although platelet yield significantly correlated with the donor platelet count however quality of RDPs in terms of red cell contamination showed no correlation with the donor hematocrit. Platelet yield in random donor platelets is a concern in Eastern India. A platelet yield of 4.5 × 10(10) per bag as mandated by the DCA of India was only achieved when the donor platelet count was >200 × 10(6)/ml. Posttransfusion platelet recovery (PPR) was unsatisfactory in the transfused patient. Introduction of pre-donation platelet count in whole blood donation will maximize donor safety and optimize patient platelet transfusion management.

  10. [Single-donor (apheresis) platelets and pooled whole-blood-derived platelets--significance and assessment of both blood products].

    Science.gov (United States)

    Hitzler, Walter E

    2014-01-01

    The transfusion efficacy of ATK, which contain fully functional platelets, is beyond all doubt. The equivalence of ATK and PTK has been subject of many studies. Some of those studies show the superiority of ATK's, while others do not, but there have been no studies that demonstrated a superiority of PTK's. The superiority of platelets stored in plasma and in third generation additive solution was demonstrated in clinical studies; therefore, it cannot be said that all the platelet concentrates on the German market are equivalent in efficacy. Of decisive importance, above all, is the risk of transfusion-transmitted infections with known pathogens, or those not yet discovered. This risk is different for ATK compared to PTK. Taking this difference in risk and the difference in donor exposure of transfused patients into account, it can definitely be said that ATK and PTK are not equivalent. In 2012, the Robert-Koch-Institute (RKI) published a mathematical risk model for different platelet concentrates and assessed the risk of transmitting known pathogens such as HIV, HCV, and HBV. The risk was higher for PTK compared to ATK. The relative risks for PTK derived from 4BCs were 2.2 (95%--CI: 2.1-2.4) for HIV, 2.7 (95%--CI: 2.5-3.0) for HCV, and 2.2 (95%--CI: 2.8-3.7) for HBV. At the present time, these are the relative risks of transfusion-transmitted infections with the traditional pathogens for PTK compared to ATK. In addition to the RKI assessed risks, there is the theoretical risk of a new, unknown agent, transmitted through blood exposure. The magnitude of this risk is hardly predictable for PTK. The experience gathered so far, especially in the last three decades, with the emergence of HIV, prions, and West Nil virus, shows that the biological nature of a next transfusion-transmissible infectious agent cannot be predictable. This agent, if we think at a conventional sexually transmissible agent with nucleic acid and long latent period, would spread first in areas with

  11. [Risk Assessment of Single-Donor (Apheresis) Platelet Concentrates and Pooled Whole-Blood-Derived Platelet Concentrates].

    Science.gov (United States)

    Hitzler, Walter; Hutschenreuter, Gabriele; Wartensleben, Herbert

    2015-01-01

    According to the risk estimates of the Robert-Koch-Institute (RKI) and the Paul Ehrlich-Institute (PEI) an equivalence cannot be assumed to exist between the two different platelet preparations. Differences between single-donor (apheresis) platelet concentrates (ATK) and pooled whole-blood-derived platelet concentrates (PTK) result from donor populations, donation intervals, and preparation techniques. There are no prospective randomized studies with regard to the clinical efficacy, which would unambiguously demonstrate equivalence of the therapeutic efficacy of PTK (buffy coat method) in comparison to ATK. The German Association of Blood Transfusion Services (StKB) points out that, due to the non-equivalence of PTK and ATK, it is incumbent on the transfusion physician to select the platelet concentrate, make the appropriate disclosures, and assume treatment responsibility. Proper compensation for ATK and PTK must be ensured by the health insurance companies, whereby a special indication for the selection of either PTK or ATK is not given. Exceptions are patients with known HLA antibodies in which only selected platelet concentrates may be administered. Otherwise, no indication exists in the selection of the different platelet concentrates (Article is in German).

  12. Vasopressin elevation of Na+/H+ exchange is inhibited by genistein in human blood platelets.

    Science.gov (United States)

    Aharonovits, O; Zik, M; Livne, A A; Granot, Y

    1992-12-01

    The regulation of intracellular Na+ and pHi in human blood platelets is known to be controlled by the function of the Na+/H+ exchanger. The phosphorylation state of the Na+/H+ exchanger which determines the exchanger activity in human blood platelets is regulated by the activities of protein kinases and protein phosphatases. Observations in this study indicate that arginine vasopressin (AVP) that interacts with a V1 receptor, activates the Na+/H+ exchange in human blood platelets through a genistein-inhibited mechanism. The AVP-activated Na+/H+ exchange is probably not regulated by protein kinase C (PKC), since this activation is not inhibited by staurosporine. The multiple ways in which platelet Na+/H+ exchange can be modulated may indicate the critical role played by this exchanger in the homeostasis control of pHi in human blood platelets.

  13. Homocysteine and its thiolactone may promote apoptotic events in blood platelets in vitro.

    Science.gov (United States)

    Olas, Beata; Malinowska, Joanna; Rywaniak, Joanna

    2010-01-01

    The actions of homocysteine and its major metabolite, cyclic thioester, homocysteine thiolactone on endothelial cells, blood platelets, plasmatic fibrinogen and plasminogen--the important major components of haemostasis, regulating the flowing properties of blood--are complex and sometimes controversial. Homocysteine (Hcys) can promote apoptosis in endothelial cells, but the role of Hcys and its thiolactone in the apoptotic process in blood platelets is unknown. In order to study the appearance of apoptosis in platelets after treatment with the reduced form of Hcys or its thiolactone different markers were chosen: annexin V binding (phosphatidylserine exposure), platelet microparticle formation, mitochondrial membrane depolarization and αIIbβ3 expression in vitro. Apoptotic events and platelet activation were measured by a flow cytometer. In gel-filtered platelets treated with different concentrations of the reduced form of Hcys (25, 50 and 100 µM, 10 min) a significant increase of phosphatidylserine exposure (about 37% at the highest concentration, p < 0.001) and platelet microparticle formation were observed. Homocysteine caused also a dose-dependent depolarization of mitochondrial potential. The same apoptotic markers appeared in HTL-treated platelets (0.2 and 1 µM). Moreover, resveratrol (25 µM), a well known antioxidant, distinctly reduced the level of apoptotic markers. The obtained results indicate that Hcys and its thiolactone may promote in vitro apoptotic events in human gel-filtered platelets.

  14. Investigating the fluid mechanics behind red blood cell-induced lateral platelet motion

    Science.gov (United States)

    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.

  15. Where do the platelets go? A simulation study of fully resolved blood flow through aneurysmal vessels

    NARCIS (Netherlands)

    Mountrakis, L.; Lorenz, E.; Hoekstra, A.G.

    2013-01-01

    Despite the importance of platelets in the formation of a thrombus, their transport in complex flows has not yet been studied in detail. In this paper we simulated red blood cells and platelets to explore their transport behaviour in aneurysmal geometries. We considered two aneurysms with different

  16. Helicobacter pylori urease activates blood platelets through a lipoxygenase-mediated pathway.

    Science.gov (United States)

    Wassermann, German E; Olivera-Severo, Deiber; Uberti, Augusto F; Carlini, Célia R

    2010-07-01

    The bacterium Helicobacter pylori causes peptic ulcers and gastric cancer in human beings by mechanisms yet not fully understood. H. pylori produces urease which neutralizes the acidic medium permitting its survival in the stomach. We have previously shown that ureases from jackbean, soybean or Bacillus pasteurii induce blood platelet aggregation independently of their enzyme activity by a pathway requiring platelet secretion, activation of calcium channels and lipoxygenase-derived eicosanoids. We investigated whether H. pylori urease displays platelet-activating properties and defined biochemical pathways involved in this phenomenon. For that the effects of purified recombinant H. pylori urease (HPU) added to rabbit platelets were assessed turbidimetrically. ATP secretion and production of lipoxygenase metabolites by activated platelets were measured. Fluorescein-labelled HPU bound to platelets but not to erythrocytes. HPU induced aggregation of rabbit platelets (ED(50) 0.28 microM) accompanied by ATP secretion. No correlation was found between platelet activation and ureolytic activity of HPU. Platelet aggregation was blocked by esculetin (12-lipoxygenase inhibitor) and enhanced approximately 3-fold by indomethacin (cyclooxygenase inhibitor). A metabolite of 12-lipoxygenase was produced by platelets exposed to HPU. Platelet responses to HPU did not involve platelet-activating factor, but required activation of verapamil-inhibitable calcium channels. Our data show that purified H. pylori urease activates blood platelets at submicromolar concentrations. This property seems to be common to ureases regardless of their source (plant or bacteria) or quaternary structure (single, di- or tri-chain proteins). These properties of HPU could play an important role in pathogenesis of gastrointestinal and associated cardiovascular diseases caused by H. pylori.

  17. Platelet adhesion from shear blood flow is controlled by near-wall rebounding collisions with erythrocytes.

    Science.gov (United States)

    Tokarev, A A; Butylin, A A; Ataullakhanov, F I

    2011-02-16

    The efficacy of platelet adhesion in shear flow is known to be substantially modulated by the physical presence of red blood cells (RBCs). The mechanisms of this regulation remain obscure due to the complicated character of platelet interactions with RBCs and vascular walls. To investigate this problem, we have created a mathematical model that takes into account shear-induced transport of platelets across the flow, platelet expulsion by the RBCs from the near-wall layer of the flow onto the wall, and reversible capture of platelets by the wall and their firm adhesion to it. This model analysis allowed us to obtain, for the first time to our knowledge, an analytical determination of the platelet adhesion rate constant as a function of the wall shear rate, hematocrit, and average sizes of platelets and RBCs. This formula provided a quantitative description of the results of previous in vitro adhesion experiments in perfusion chambers. The results of the simulations suggest that under a wide range of shear rates and hematocrit values, the rate of platelet adhesion from the blood flow is mainly limited by the frequency of their near-wall rebounding collisions with RBCs. This finding reveals the mechanism by which erythrocytes physically control platelet hemostasis.

  18. Platelets and white blood cells in acute coronary syndromes

    NARCIS (Netherlands)

    Smit, Jaap Jan Johannes

    2008-01-01

    In this thesis, we have studied the role of leukocytes and platelets as methods to measure platelets aggregation, in the clinical management of presenting with acute coronary syndromes. We have tried to incidence and to identify predictors of adverse cardiac events with function tests or inflammator

  19. Amikacin can be added to blood to reduce the fall in platelet count.

    Science.gov (United States)

    Zhou, Xiaomian; Wu, Xiaoli; Deng, Weixiong; Li, Jieqiu; Luo, Wenshen

    2011-10-01

    Our objective was to develop an effective method to prevent the fall in platelet count for patients with anticoagulant-dependent (AD) pseudothrombocytopenia, a spurious phenomenon due to anticoagulant-induced aggregation of platelets. We report a case of insidious multianticoagulant-dependent pseudothrombocytopenia in which AD pseudothrombocytopenia may be caused by 4 anticoagulants, eg, EDTA, sodium citrate, heparin, and sodium fluoride (NaF). Multianticoagulant-dependent pseudothrombocytopenia was confirmed by finding clumped platelets on microscopic evaluation in 4 anticoagulated blood samples. With this case, we tried a variety of reagents, including aminoglycosides, eg, gentamicin and amikacin, vitamin B(6), and aminophylline to inhibit pseudothrombocytopenia. Except for amikacin, all reagents failed to prevent pseudothrombocytopenia. Microscopic examination of K(2)-EDTA-, heparin-, sodium citrate-, and NaF-anticoagulated blood samples showed massive platelet clumping, but no aggregate was seen in the anticoagulated blood with amikacin. When amikacin was added within 1 hour after blood sample withdrawal, platelet, WBC, and RBC counts and hemoglobin level, mean corpuscular volume, and mean platelet volume remained unchanged for up to 4 hours at room temperature. These findings suggest that amikacin could inhibit and dissociate pseudo platelet aggregation in multianticoagulant-dependent pseudothrombocytopenia and EDTA-induced pseudothrombocytopenia.

  20. Proteomics meets blood banking: identification of protein targets for the improvement of platelet quality.

    Science.gov (United States)

    Schubert, Peter; Devine, Dana V

    2010-01-01

    Proteomics has brought new perspectives to the fields of hematology and transfusion medicine in the last decade. The steady improvement of proteomic technology is propelling novel discoveries of molecular mechanisms by studying protein expression, post-translational modifications and protein interactions. This review article focuses on the application of proteomics to the identification of molecular mechanisms leading to the deterioration of blood platelets during storage - a critical aspect in the provision of platelet transfusion products. Several proteomic approaches have been employed to analyse changes in the platelet protein profile during storage and the obtained data now need to be translated into platelet biochemistry in order to connect the results to platelet function. Targeted biochemical applications then allow the identification of points for intervention in signal transduction pathways. Once validated and placed in a transfusion context, these data will provide further understanding of the underlying molecular mechanisms leading to platelet storage lesion. Future aspects of proteomics in blood banking will aim to make use of protein markers identified for platelet storage lesion development to monitor proteome changes when alterations such as the use of additive solutions or pathogen reduction strategies are put in place in order to improve platelet quality for patients.

  1. Accurate measurement of volume and shape of resting and activated blood platelets from light scattering.

    Science.gov (United States)

    Moskalensky, Alexander E; Yurkin, Maxim A; Konokhova, Anastasiya I; Strokotov, Dmitry I; Nekrasov, Vyacheslav M; Chernyshev, Andrei V; Tsvetovskaya, Galina A; Chikova, Elena D; Maltsev, Valeri P

    2013-01-01

    We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 μM adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.

  2. Accurate measurement of volume and shape of resting and activated blood platelets from light scattering

    Science.gov (United States)

    Moskalensky, Alexander E.; Yurkin, Maxim A.; Konokhova, Anastasiya I.; Strokotov, Dmitry I.; Nekrasov, Vyacheslav M.; Chernyshev, Andrei V.; Tsvetovskaya, Galina A.; Chikova, Elena D.; Maltsev, Valeri P.

    2013-01-01

    We introduce a novel approach for determination of volume and shape of individual blood platelets modeled as an oblate spheroid from angle-resolved light scattering with flow-cytometric technique. The light-scattering profiles (LSPs) of individual platelets were measured with the scanning flow cytometer and the platelet characteristics were determined from the solution of the inverse light-scattering problem using the precomputed database of theoretical LSPs. We revealed a phenomenon of parameter compensation, which is partly explained in the framework of anomalous diffraction approximation. To overcome this problem, additional a priori information on the platelet refractive index was used. It allowed us to determine the size of each platelet with subdiffraction precision and independent of the particular value of the platelet aspect ratio. The shape (spheroidal aspect ratio) distributions of platelets showed substantial differences between native and activated by 10 μM adenosine diphosphate samples. We expect that the new approach may find use in hematological analyzers for accurate measurement of platelet volume distribution and for determination of the platelet activation efficiency.

  3. Interaction of inorganic nanoparticles of lunar soil simulant with blood platelets

    Science.gov (United States)

    Borisova, Tatiana; Kasatkina, Ludmila; Krisanova, Natalia; Sivko, Roman; Borisov, Arseniy; Slenzka, Klaus

    Blood platelets play a central role in the physiology of primary hemostasis and in the patholog-ical processes of arterial thrombosis. Also, blood platelets contain neuronal high-affinity Na+-dependent glutamate transporters (EAAT 1 -3) and are able to uptake glutamate, thereby playing possible physiological role in extracellular glutamate homeostasis in the mammalian CNS as an additional powerful target for excessive neurotoxic glutamate accumulation and storage. The health effects of lunar soil exposure are almost completely unknown, whereas the observations suggest that it can be deleterious to human physiology. It is important that the components of lunar soil may be internalized with lipid fractions of the lung epithelium, which in turn may help ions to overcome the blood-brain barrier. The study focused on the effects of JSC-1a Lunar Soil Simulant (LSS) (Orbital Technologies Corporation, Madison, USA) on platelets isolated from rabbit blood. We revealed that platelets were not indifferent to the expo-sure to LSS. Flow cytometric analysis showed that the incubation of platelets with LSS resulted in an upper shift of platelet spot in histograms presenting cell size (FS) and granularity (SS) as x and y coordinates, thereby demonstrating apparent increase in platelet granularity. Analysis of control platelet preparation did not reveal the alterations in platelet size and granularity during the same incubation period. LSS scatter per se did not cover area of platelet prepara-tion in histogram. Using Zetasizer Nanosystem (Malvern Instruments) with helium-neon laser for dynamic light scattering (DLS), the platelet size before and after the addition of LSS was measured. We have found the increase in the mean size of the population of platelets from 2.45 ±0.09 µm in control to 3.0 ± 0.25 µm in the presence of LSS. Thus, we report that inorganic nanoparticles of LSS bind to blood platelets and this fact may have considerable harmful conse-quences to human

  4. Catabolism of exogenously supplied thymidine to thymine and dihydrothymine by platelets in human peripheral blood

    Energy Technology Data Exchange (ETDEWEB)

    Pero, R.W.; Johnson, D.; Olsson, A.

    1984-11-01

    The interference of platelets with the estimation of unscheduled DNA synthesis in human peripheral mononuclear leukocytes following genotoxic exposure was studied. A 96% reduction in the unscheduled DNA synthesis value was achieved by incubating (/sup 3/H)thymidine with platelet-rich plasma for 5 hr at 37 degrees. Using radioactive thymine-containing compounds, together with quantitative analyses based on thin-layer and ion-exchange chromatographies, we have shown that thymidine was converted to thymine which, in turn, was converted to dihydrothymine in platelet-rich plasma. The enzymes responsible were separated from platelet lysates by gel filtration and were identified as thymidine phosphorylase and dihydrothymine dehydrogenase. The phosphorylase reversibly catalyzed the formation of thymine from thymidine and converted bromodeoxyuridine to bromouracil. The dehydrogenase reversibly catalyzed the interconversion of thymine and dihydrothymine in a reaction dependent on NADP(H), and it was inhibited by diazouracil and by thymine. Nearly all the thymidine-catabolizing activity found in whole blood samples supplied exogenously with thymidine was accounted for by the platelets. Since most genetic toxicological tests that use blood samples do not involve removing platelets from the blood cell cultures, then it is concluded that precautions should be taken in the future to determine the influence of platelets on these test systems. This is particularly true for methods dependent on thymidine pulses such as unscheduled DNA synthesis, or those dependent on bromodeoxyuridine, such as sister chromatid exchanges, since this nucleoside is also a substrate for thymidine phosphorylase.

  5. Determination of volume, shape and refractive index of individual blood platelets

    CERN Document Server

    Kolesnikova, Irina V; Yurkin, Maxim A; Hoekstra, Alfons G; Maltsev, Valeri P; Semyanov, Konstantin A

    2008-01-01

    Light scattering patterns (LSP) of blood platelets were theoretically and experimentally analyzed. We used spicular spheroids as a model for the platelets with pseudopodia. The discrete dipole approximation was employed to simulate light scattering from an individual spicular spheroid constructed from a homogeneous oblate spheroid and 14 rectilinear parallelepipeds rising from the cell centre. These parallelepipeds have a weak effect on the LSP over the measured angular range. Therefore, a homogeneous oblate spheroid was taken as a simplified optical model for platelets. Using the T-matrix method, we computed the LSP over a range of volumes, aspect ratios and refractive indices. Measured LSPs of individual platelets were compared one by one with the theoretical set and the best fit was taken to characterize the measured platelets, resulting in distributions of volume, aspect ratio and refractive index.

  6. Assessing anxiety levels and empathic tendency in blood and platelet donors.

    Science.gov (United States)

    Kılıç, Suar Çakı; Doğan, Erdoğan; Sevimligül, Gülgün; Yücel, Birsen; Bolat, Fatih; Kavakçı, Onder; Sencan, Mehmet

    2013-06-01

    In spite of a constantly-increasing requirement for blood transfusion in the world, blood donation does not exhibit an increase at the same rate. In Turkey with a population of 74 million, only 15 per 10,000 people donate blood regularly and rate of voluntary blood donation is very low compared to developed countries. The aim of this study is to determine empathic level of donors and anxiety levels of blood and platelet donors and also to enable comfort and motivation of donors by taking precautions for reducing their anxieties. This prospective and descriptive study was conducted with 100 voluntary donors (50 blood donors, 50 platelet donors) who admitted to Blood Centre of Cumhuriyet University Hospital between 15 March 2012 and 30 April 2012. Average age of these donors was 27 (19-48)years. The mean scores of donors from Empathic Tendency Scale (ETS), State Anxiety Invertory (SAI) and Trait Anxiety Inventory (TAI) were 70 (49-83), 40 (33-45) and 34 (30-44), respectively. ETS score of those donating blood/platelet for the first time was low, >1 is higher in those who donated previously. SAI and TAI scores of blood donors were higher than those of platelet donors (pempathy. Donation made during the continuous disclosure is an important factor for being a donor.

  7. Value of blood-pool subtraction in cardiac indium-111-labeled platelet imaging

    Energy Technology Data Exchange (ETDEWEB)

    Machac, J.; Vallabhajosula, S.; Goldman, M.E.; Goldsmith, S.J.; Palestro, C.; Strashun, A.; Vaquer, R.; Phillips, R.A.; Fuster, V. (Mt. Sinai Medical Center, New York, NY (USA))

    1989-09-01

    Blood-pool subtraction has been proposed to enhance {sup 111}In-labeled platelet imaging of intracardiac thrombi. We tested the accuracy of labeled platelet imaging, with and without blood-pool subtraction, in ten subjects with cardiac thrombi of varying age, eight with endocarditis being treated with antimicrobial therapy and ten normal controls. Imaging was performed early after labeled platelet injection (24 hr or less) and late (48 hr or more). Blood-pool subtraction was carried out. All images were graded subjectively by four experienced, blinded readers. Detection accuracy was measured by the sensitivity at three fixed levels of specificity estimated from receiver operator characteristic curve analysis and tested by three-way analysis of variance. Detection accuracy was generally improved on delayed images. Blood-pool subtraction did not improve accuracy. Although blood-pool subtraction increased detection sensitivity, this was offset by decreased specificity. For this population studied, blood-pool subtraction did not improve subjective detection of abnormal platelet deposition by 111In platelet imaging.

  8. Platelet proteomics and its advanced application for research of blood stasis syndrome and activated blood circulation herbs of Chinese medicine.

    Science.gov (United States)

    Liu, Yue; Yin, Huijun; Chen, Keji

    2013-11-01

    The development of novel and efficient antiplatelet agents that have few adverse effects and methods that improve antiplatelet resistance has long been the focus of international research on the prevention and treatment of cardiovascular and cerebrovascular diseases. Recent advances in platelet proteomics have provided a technology platform for high-quality research of platelet pathophysiology and the development of new antiplatelet drugs. The study of blood stasis syndrome (BSS) and activated blood circulation of traditional Chinese medicine (TCM) is one of the most active fields where the integration of TCM and western medicine in China has been successful. Activated blood circulation herbs (ABC herbs) of Chinese medicine are often used in the treatment of BSS. Most ABC herbs have antiplatelet and anti-atherosclerosis activity, but knowledge about their targets is lacking. Coronary heart disease (CHD), BSS, and platelet activation are closely related. By screening and identifying activated platelet proteins that are differentially expressed in BSS of CHD, platelet proteomics has helped researchers interpret the antiplatelet mechanism of action of ABC herbs and provided many potential biomarkers for BSS that could be used to evaluate the clinical curative effect of new antiplatelet drugs. In this article the progress of platelet proteomics and its advanced application for research of BSS and ABC herbs of Chinese medicine are reviewed.

  9. cAMP signaling in blood platelets - old friends and new players.

    Directory of Open Access Journals (Sweden)

    Zaher eRaslan

    2015-11-01

    Full Text Available Atherothrombosis, the pathology underlying numerous cardiovascular diseases, is a major cause of death globally. Hyperactive blood platelets play a key role in the atherothrombotic process through the release of inflammatory mediators and formation of thrombi. In healthy blood vessels, excessive platelet activation is restricted by endothelial-derived prostacyclin (PGI2 through cyclic adenosine-5’-monophosphate (cAMP and protein kinase A (PKA-dependent mechanisms. Elevation in intracellular cAMP is associated with the control of a number of distinct platelet functions including actin polymerisation, granule secretion, calcium mobilisation and integrin activation. Unfortunately, in atherosclerotic disease the protective effects of cAMP are compromised, which may contribute to pathological thrombosis. The cAMP signalling network in platelets is highly complex with the presence of multiple isoforms of adenylyl cyclase (AC, PKA and phosphodiesterases (PDE. However, a precise understanding of the relationship between specific AC, PKA and PDE isoforms, and how individual signalling substrates are targeted to control distinct platelet functions is still lacking. In other cells types, compartmentalisation of cAMP signalling has emerged as a key mechanism to allow precise control of specific cell functions. A-kinase anchoring proteins (AKAPs play an important role in this spatiotemporal regulation of cAMP signalling networks. Evidence of AKAP-mediated compartmentalisation of cAMP signalling in blood platelets has begun to emerge and is providing new insights into the regulation of platelet function. Dissecting the mechanisms that allow cAMP to control excessive platelet activity without preventing effective haemostasis may unleash the possibility of therapeutic targeting of the pathway to control unwanted platelet activity.

  10. Effect of Red Blood Cells on Platelet Activation and Thrombus Formation in Tortuous Arterioles.

    Science.gov (United States)

    Chesnutt, Jennifer K W; Han, Hai-Chao

    2013-01-01

    Thrombosis is a major contributor to cardiovascular disease, which can lead to myocardial infarction and stroke. Thrombosis may form in tortuous microvessels, which are often seen throughout the human body, but the microscale mechanisms and processes are not well understood. In straight vessels, the presence of red blood cells (RBCs) is known to push platelets toward walls, which may affect platelet aggregation and thrombus formation. However in tortuous vessels, the effects of RBC interactions with platelets in thrombosis are largely unknown. Accordingly, the objective of this work was to determine the physical effects of RBCs, platelet size, and vessel tortuosity on platelet activation and thrombus formation in tortuous arterioles. A discrete element computational model was used to simulate the transport, collision, adhesion, aggregation, and shear-induced platelet activation of hundreds of individual platelets and RBCs in thrombus formation in tortuous arterioles. Results showed that high shear stress near the inner sides of curved arteriole walls activated platelets to initiate thrombosis. RBCs initially promoted platelet activation, but then collisions of RBCs with mural thrombi reduced the amount of mural thrombus and the size of emboli. In the absence of RBCs, mural thrombus mass was smaller in a highly tortuous arteriole compared to a less tortuous arteriole. In the presence of RBCs however, mural thrombus mass was larger in the highly tortuous arteriole compared to the less tortuous arteriole. As well, smaller platelet size yielded less mural thrombus mass and smaller emboli, either with or without RBCs. This study shed light on microscopic interactions of RBCs and platelets in tortuous microvessels, which have implications in various pathologies associated with thrombosis and bleeding.

  11. Acquired platelet function defect

    Science.gov (United States)

    Acquired qualitative platelet disorders; Acquired disorders of platelet function ... blood clotting. Disorders that can cause problems in platelet function include: Idiopathic thrombocytopenic purpura Chronic myelogenous leukemia Multiple ...

  12. Simulation of the Effect of Red Blood Cell Collisions on Platelet Adsorption

    Science.gov (United States)

    Fitzgibbon, Sean; Zhao, Hong; Shaqfeh, Eric

    2012-11-01

    The adsorption of platelets to the endothelial wall is an important first step in the clotting process, which is critical to stopping blood loss after trauma. Initial platelet arrest is controlled by very short range interaction between two proteins, von Willibrand Factor and GPIb, so the rate of platelet adsorption is expected to be strongly dependent on the rate at which the platelets sample the wall. With Peclet numbers in the range (103 - 105) , simple diffusive arguments are not sufficient to explain the high rates of platelet adsorption. Using Stokes flow simulations, we show that the platelets' wall sampling rate is significantly increased by interactions with red blood cells. Our simulation models platelets as rigid bodies suspended in a Stokesian linear shear flow. We solve for the flow using standard boundary integral techniques with the appropriate single wall bounded Green's function. Receptor-ligand interactions are represented as Hookean springs with characteristic lifetimes, sizes, and stiffness coefficients. Drag forces are calculated with the reciprocal theorem, and RBC collisions are modelled as AR processes extracted from the large scale suspension simulations of Zhao et al.

  13. Statin-induced changes in mitochondrial respiration in blood platelets in rats and human with dyslipidemia.

    Science.gov (United States)

    Vevera, J; Fišar, Z; Nekovářová, T; Vrablík, M; Zlatohlávek, L; Hroudová, J; Singh, N; Raboch, J; Valeš, K

    2016-11-23

    3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins) are widely used drugs for lowering blood lipid levels and preventing cardiovascular diseases. However, statins can have serious adverse effects, which may be related to development of mitochondrial dysfunctions. The aim of study was to demonstrate the in vivo effect of high and therapeutic doses of statins on mitochondrial respiration in blood platelets. Model approach was used in the study. Simvastatin was administered to rats at a high dose for 4 weeks. Humans were treated with therapeutic doses of rosuvastatin or atorvastatin for 6 weeks. Platelet mitochondrial respiration was measured using high-resolution respirometry. In rats, a significantly lower physiological respiratory rate was found in intact platelets of simvastatin-treated rats compared to controls. In humans, no significant changes in mitochondrial respiration were detected in intact platelets; however, decreased complex I-linked respiration was observed after statin treatment in permeabilized platelets. We propose that the small in vivo effect of statins on platelet energy metabolism can be attributed to drug effects on complex I of the electron transport system. Both intact and permeabilized platelets can be used as a readily available biological model to study changes in cellular energy metabolism in patients treated with statins.

  14. Clinical and blood bank factors in the management of platelet refractoriness and alloimmunization.

    Science.gov (United States)

    Friedberg, R C; Donnelly, S F; Boyd, J C; Gray, L S; Mintz, P D

    1993-06-15

    Numerous independent and interdependent factors are involved in the posttransfusion platelet response. Factors such as ABO match and platelet age are related to circumstances potentially under the control of the blood bank physician and therefore may permit circumvention by an active transfusion service. On the other hand, factors such as fever or sepsis may be unavoidable, being related more to the individual patient or clinical condition. To evaluate which factors could be circumvented, we prospectively followed the 1-hour corrected count increments (CCIs) for 962 single-donor apheresis platelet transfusions to 71 refractory hematologic oncology inpatients, with concomitant recording of implicated factors. Stepwise regression analysis allowed for determination of which concurrent and confounding clinical-, patient-, and blood bank-related factors significantly affected the CCIs. Although many implicated factors proved to be independently associated with an increased or decreased CCI, we found that no single variable consistently explained the CCI variation across the patient population. Each patient appeared sensitive to one or a few particular factors, but because of marked intraindividual variation, it was not possible to identify a priori which factors were important for a given patient. The single exception was a solid-phase red blood cell adherence assay used to cross-match platelets, but only for alloimmunized patients. We also evaluated the utility of requesting HLA-matched platelets from the local suppliers and maintained a clear distinction between platelets simply ordered as HLA matched and actually HLA-identical platelets. Accounting for the confounding clinical-, patient-, and blood bank-related factors, the cross-match assay was a better predictor of an adequate CCI than ordering platelets as HLA matched.

  15. The influence of Rubus idaeus and Rubus caesius leaf extracts on platelet aggregation in whole blood. Cross-talk of platelets and neutrophils.

    Science.gov (United States)

    Dudzinska, Dominika; Bednarska, Katarzyna; Boncler, Magdalena; Luzak, Boguslawa; Watala, Cezary

    2016-07-01

    Recently, polyphenols have gained attention as potential natural cardioprotective therapeutics, due to their antiplatelet, anti-inflammatory and anticoagulant activity. Species belonging to the genus Rubus sp. have been reported to be a source of polyphenolic compounds with antioxidative proprieties and beneficial biological activities. This study investigates the effects of leaf extracts obtained from red raspberry (Rubus idaeus L.) and European dewberry (Rubus caesius L.) on the reactivity of blood platelets. In ADP-stimulated blood, raspberry and dewberry extracts (15 µg/ml) markedly decreased platelet surface membrane expression of activated GPIIbIIIa receptor by 16% and 21%, respectively (P raspberry and by 38-55% for dewberry, P raspberry and dewberry leaf extracts considerably modulated blood platelet reactivity in whole blood: they influenced blood platelet aggregation, possibly via the modulation of the redox status dependent on the oxidative activity of neutrophils.

  16. Morphological evaluation of canine platelets on Giemsa- and PAS-stained blood smears.

    Science.gov (United States)

    Halmay, Dóra; Sótonyi, P; Vajdovich, P; Gaál, T

    2005-01-01

    The morphology of canine platelets (changes in size, shape, staining characteristics, degree of activation and clump formation, distribution of granules, appearance of vacuoles on Giemsa-stained smears) was investigated in 20 healthy control and 181 diseased dogs. In the group of the sick dogs 84 animals suffered from disorders affecting directly the haematological parameters or the haematopoietic organs such as bleeding, thymic haemorrhage, haemolytic disorders, lymphoma, immune-mediated thrombocytopenia, and other 97 dogs were affected by other diseases (hepatopathy, nephropathy, hepatic, splenic or intestinal neoplasm, skin diseases, diabetes mellitus, Cushing's syndrome, sepsis). The alterations found in platelet morphology were not specific for any disorder. The most common platelet abnormalities were polychromasia and the presence of giant platelets. These changes occurred in a high number in disorders accompanied by bleeding or haemolysis. Anisocytosis was the most frequent finding in hepatic, splenic or intestinal neoplasms and in certain endocrinopathies. Microcytosis was observed in immune-mediated thrombocytopenia, hepatic neoplasms and endocrine disorders. Extreme platelet activation was common in haemolysis, hepatopathies, neoplastic diseases and sepsis. Vacuolisation was present in thymic haemorrhage, pancreatitis, diabetes mellitus and Cushing's syndrome. A new morphologic phenomenon, i.e. a ring-like formation of granules, was described in the cytoplasm of the platelets both in healthy and diseased animals. In addition, two forms of pathologic granulation were also described for the first time in Giemsa-stained blood smears: the pseudonuclear and the spot-like formation of granules, which were observed especially in disorders affecting the blood cells. The granulation and morphological characteristics of platelets on smears stained by periodic acid-Schiff reaction (PAS) were also studied. Three localisations of granulation were observed, such as

  17. Blood platelet and monocyte activations and relation to stages of liver cirrhosis

    Institute of Scientific and Technical Information of China (English)

    Anatol Panasiuk; Janusz Zak; Edwina Kasprzycka; Katarzyna Janicka; Danuta Prokopowicz

    2005-01-01

    AIM: Blood platelets (plt) and monocytes are the cells that play a crucial role in the pathogenesis of liver damage and liver cirrhosis (LC). In this paper, the analysis of mutual relationship between platelets and monocytes activation in LC was conducted.METHODS: Immunofluorescent flow cytometry was usedto measure the percentage of activated platelet populations(CD62P, CD63), the percentage of plt-monocyte aggregates (pma) (CD41/CD45), and activated monocytes (CD11b, CD14, CD16) in the blood of 20 volunteers and 40 patientswith LC. Platelet activation markers: sP-selectin, platelet factor 4 (PF4), beta-thromboglobulin (βTG) and monocyte chemotactic peptide-1 (MCP-1) were measured and compared in different stages of LC.RESULTS: Platelet activation with the increase in bothβTG serum concentration and elevation of plt population(CD62P and CD63 as well as MIF CD62P and CD63) is elevated as LC develops and thrombocytopenia rises. There is a positive correlation between medial intensityof fluorescence (MIF) CD62P and MIF CD63 in LC. We did not show any relationship between monocyte activation and pma level. SP-selectin concentration correlates positively with plt count and pma, and negatively with stage of plt activation and MIF CD62P and MIF CD63. There was no correlation between MCP-1 concentration andpit, monocyte activation as well as pma level in LC. CD16 monocytes and MIF CD16 populations are significantlyhigher in the end stage of LC. A positive correlation occurs between the value of CD11b monocyte population andMIF CD14 and MIF CD16 on monocytes in LC.CONCLUSION: Platelet and monocyte activation plays an important role in LC. Platelet activation stage does not influence monocyte activation and production of plt aggregates with monocytes in LC. With LC development, thrombocytopenia may be the result of plt consumption in platelet-monocyte aggregates.

  18. Fabricating bio-inspired micro/nano-particles by polydopamine coating and surface interactions with blood platelets

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Wei [Jiangsu Provincial Key Lab for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Shi, Qiang, E-mail: shiqiang@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Hou, Jianwen; Gao, Jian; Li, Chunming; Jin, Jing; Shi, Hengchong [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China); Yin, Jinghua, E-mail: yinjh@ciac.ac.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)

    2015-10-01

    Graphical abstract: The particles or particle aggregations activate the blood platelets and provide the physical adhesive sites for platelets adhesion. - Highlights: • Particles with varied sizes and surface properties were fabricated by facile polydopamine (PDA) coating on polystyrene microsphere. • The direct interaction between PDA particles and blood platelets was qualitatively investigated. • The knowledge on platelet–particle interactions provided the basic principle to select biocompatible micro/nano-particles in biomedical field. - Abstract: Although bio-inspired polydopamine (PDA) micro/nano-particles show great promise for biomedical applications, the knowledge on the interactions between micro/nano-particles and platelets is still lacking. Here, we fabricate PDA-coated micro/nano-particles and investigate the platelet–particle surface interactions. Our strategy takes the advantage of facile PDA coating on polystyrene (PS) microsphere to fabricate particles with varied sizes and surface properties, and the chemical reactivity of PDA layers to immobilize fibrinogen and bovine serum albumin to manipulate platelet activation and adhesion. We demonstrate that PS particles activate the platelets in the size-dependent manner, but PDA nanoparticles have slight effect on platelet activation; PS particles promote platelet adhesion while PDA particles reduce platelet adhesion on the patterned surface; Particles interact with platelets through activating the glycoprotein integrin receptor of platelets and providing physical sites for initial platelet adhesion. Our work sheds new light on the interaction between platelets and particles, which provides the basic principle to select biocompatible micro/nano-particles in biomedical field.

  19. PLATELET-LEUKOCYTE INTERACTIONS : MULTIPLE LINKS BETWEEN INFLAMMATION , BLOOD COAGULATION AND VASCULAR RISK

    Directory of Open Access Journals (Sweden)

    Chiara Cerletti

    2010-08-01

    Full Text Available The aim of this review is to summarize the contribution of platelets and leukocytes and their interactions in inflammation and blood coagulation and its possible relevance in the pathogenesis of  thrombosis. There is some evidence of an association between infection/inflammation and thrombosis. This is likely a bidirectional relationship. The presence of a thrombus may serve as a nidus of infection. Vascular injury indeed promotes platelet and leukocyte activation and thrombus formation and the thrombus and its components facilitate adherence of bacteria to the vessel wall. Alternatively, an infection and the associated inflammation can trigger platelet and leukocyte activation and thrombus formation. In either case platelets and leukocytes co-localize and interact in the area of vascular injury, at sites of inflammation and/or at sites of thrombosis. Following vascular injury, the subendothelial tissue, a thrombogenic surface, becomes available for interaction with these blood cells. Tissue factor, found not only in media and adventitia of the vascular wall, but also on activated platelets and leukocytes, triggers blood coagulation. Vascular-blood cell interactions, mediated by the release of preformed components of the endothelium, is modulated by both cell adhesion and production of soluble stimulatory or inhibitory molecules that alter cell function: adhesion molecules regulate cell-cell contact and facilitate the modulation of biochemical pathways relevant to inflammatory and/or thrombotic processes.

  20. Cathepsin G-dependent modulation of platelet thrombus formation in vivo by blood neutrophils.

    Directory of Open Access Journals (Sweden)

    Nauder Faraday

    Full Text Available Neutrophils are consistently associated with arterial thrombotic morbidity in human clinical studies but the causal basis for this association is unclear. We tested the hypothesis that neutrophils modulate platelet activation and thrombus formation in vivo in a cathepsin G-dependent manner. Neutrophils enhanced aggregation of human platelets in vitro in dose-dependent fashion and this effect was diminished by pharmacologic inhibition of cathepsin G activity and knockdown of cathepsin G expression. Tail bleeding time in the mouse was prolonged by a cathepsin G inhibitor and in cathepsin G knockout mice, and formation of neutrophil-platelet conjugates in blood that was shed from transected tails was reduced in the absence of cathepsin G. Bleeding time was highly correlated with blood neutrophil count in wildtype but not cathepsin G deficient mice. In the presence of elevated blood neutrophil counts, the anti-thrombotic effect of cathepsin G inhibition was greater than that of aspirin and additive to it when administered in combination. Both pharmacologic inhibition of cathepsin G and its congenital absence prolonged the time for platelet thrombus to form in ferric chloride-injured mouse mesenteric arterioles. In a vaso-occlusive model of ischemic stroke, inhibition of cathepsin G and its congenital absence improved cerebral blood flow, reduced histologic brain injury, and improved neurobehavioral outcome. These experiments demonstrate that neutrophil cathepsin G is a physiologic modulator of platelet thrombus formation in vivo and has potential as a target for novel anti-thrombotic therapies.

  1. Influence of storage conditions on the release of growth factors in platelet-rich blood derivatives

    Directory of Open Access Journals (Sweden)

    Düregger Katharina

    2016-09-01

    Full Text Available Thrombocytes can be concentrated in blood derivatives and used as autologous transplants e.g. for wound treatment due to the release of growth factors such as platelet derived growth factor (PDGF. Conditions for processing and storage of these platelet-rich blood derivatives influence the release of PDGF from the platelet-bound α-granules into the plasma. In this study Platelet rich plasma (PRP and Platelet concentrate (PC were produced with a fully automated centrifugation system. Storage of PRP and PC for 1 h up to 4 months at temperatures between −20°C and +37°C was applied with the aim of evaluating the influence on the amount of released PDGF. Storage at −20°C resulted in the highest release of PDGF in PRP and a time dependency was determined: prolonged storage up to 1 month in PRP and 10 days in PC increased the release of PDGF. Regardless of the storage conditions, the release of PDGF per platelet was higher in PC than in PRP.

  2. Platelet concentrates for topical use: bedside device and blood transfusion technology. Quality and versatility.

    Science.gov (United States)

    Borzini, Piero; Balbo, Valeria; Mazzucco, Laura

    2012-06-01

    More or less after a decade of experimental and pioneering manual procedures to prepare platelet-rich plasma (PRP) for topical use, several portable and bedside devices were made available to prepare the PRP at the point-of-care. This technical opportunity increased the number of patients who got access to the treatment with autologous PRP and PRP-gel. Since topical treatment of tissue with PRP and PRP-gel was restricted to autologous preparation, blood transfusion centers that professionally prepare donor-derived platelet concentrates were not able to cover the overwhelming request for autologous PRP supply. Principally for logistic and organization reasons blood transfusion centers usually fail the challenge of prompt delivery of PRP to the physician over large territory. Nevertheless the blood bank production of platelet concentrates is associated with high standardization and quality controls not achievable from bedside and portable devices. Furthermore it easy to demonstrate that high-volume blood bank-produced platelet concentrates are less expensive than low-volume PRP produced by portable and bedside devices. Taking also in consideration the ever-increasing safety of the blood components, the relationship between bedside device-produced and blood-bank-produced PRP might be reconsidered. Here we discuss this topic concluding that the variety of sources of PRP production is an opportunity for versatility and that, ultimately, versatility is an opportunity for the patient's care.

  3. Serotonin uptake in blood platelets of psychiatric patients

    Energy Technology Data Exchange (ETDEWEB)

    Meltzer, H.Y.; Arora, R.C.; Baber, R.; Tricou, B.J.

    1981-12-01

    Platelet serotonin (5-HT) uptake was determined in 72 newly admitted, unmedicated psychiatric patients. Decreased maximum velocity (Vmax) of 5-HT uptake was present in unipolar and bipolar depressed patients as well as schizoaffective depressed patients. The apparent Michaelis constant (km) of 5-HT uptake was normal in these groups, as was Vmax and Km in manic-depressive and chronic schizophrenic patients. Treatment of depressed patients with notriptyline hydrochloride or imipramine hydrochloride increased Km significantly. There was a trend for the increase in Km in the nortriptyline-treated patients to correlate with clinical improvement. Decreased 5-HT uptake in platelets provides additional evidence for the role of 5-HT in the pathophysiologic process of some forms of depression.

  4. Effect of flunarizine and calcium on serotonin uptake in human and rat blood platelets and rat synaptosomes

    DEFF Research Database (Denmark)

    Jensen, P N; Smith, D F; Poulsen, J H

    1994-01-01

    in blood platelets, whereas no effect was observed in synaptosomes. Flunarizine inhibited serotonin uptake in a concentration dependent manner with an IC50 value of 1 mumol/L in blood platelets and 5 mumol/L in synaptosomes. The inhibition did not depend on the presence of extracellular calcium indicating...

  5. Blood platelet-derived microparticles release and bubble formation after an open-sea air dive.

    Science.gov (United States)

    Pontier, Jean-Michel; Gempp, Emmanuel; Ignatescu, Mihaela

    2012-10-01

    Bubble-induced platelet aggregation offers an index for evaluating decompression severity in humans and in a rat model of decompression sickness. Endothelial cells, blood platelets, or leukocytes shed microparticles (MP) upon activation and during cell apoptosis. The aim was to study blood platelet MP (PMP) release and bubble formation after a scuba-air dive in field conditions. Healthy, experienced divers were assigned to 1 experimental group (n = 10) with an open-sea air dive to 30 msw for 30 min and 1 control group (n = 5) during head-out water immersion for the same period. Bubble grades were monitored with a pulsed doppler according to Kissman Integrated Severity Score (KISS). Blood samples for platelet count (PC) and PMP (annexin V and CD41) were taken 1 h before and after exposure in both groups. The result showed a decrease in post-dive PC compared with pre-dive values in experimental group with no significant change in the control group. We observed a significant increase in PMP values after the dive while no change was revealed in the control group. There was a significant positive correlation between the PMP values after the dive and the KISS bubble score. The present study highlighted a relationship between the post-dive decrease in PC, platelet MP release, and bubble formation. Release of platelet MPs could reflect bubble-induced platelet aggregation and could play a key role in alteration of the coagulation. Further studies must investigate endothelial and leukocyte MP release in the same field conditions.

  6. Classical scrapie prions in ovine blood are associated with B lymphocytes and platelet-rich plasma

    Directory of Open Access Journals (Sweden)

    Dassanayake Rohana P

    2011-11-01

    Full Text Available Abstract Background Classical scrapie is a naturally occurring transmissible spongiform encephalopathy of sheep and goats characterized by cellular accumulation of abnormal isoforms of prion protein (PrPSc in the central nervous system and the follicles of peripheral lymphoid tissues. Previous studies have shown that the whole blood and buffy coat blood fraction of scrapie infected sheep harbor prion infectivity. Although PrPSc has been detected in peripheral blood mononuclear cells (PBMCs, plasma, and more recently within a subpopulation of B lymphocytes, the infectivity status of these cells and plasma in sheep remains unknown. Therefore, the objective of this study was to determine whether circulating PBMCs, B lymphocytes and platelets from classical scrapie infected sheep harbor prion infectivity using a sheep bioassay. Results Serial rectal mucosal biopsy and immunohistochemistry were used to detect preclinical infection in lambs transfused with whole blood or blood cell fractions from preclinical or clinical scrapie infected sheep. PrPSc immunolabeling was detected in antemortem rectal and postmortem lymphoid tissues from recipient lambs receiving PBMCs (15/15, CD72+ B lymphocytes (3/3, CD21+ B lymphocytes (3/3 or platelet-rich plasma (2/3 fractions. As expected, whole blood (11/13 and buffy coat (5/5 recipients showed positive PrPSc labeling in lymphoid follicles. However, at 549 days post-transfusion, PrPSc was not detected in rectal or other lymphoid tissues in three sheep receiving platelet-poor plasma fraction. Conclusions Prion infectivity was detected in circulating PBMCs, CD72+ pan B lymphocytes, the CD21+ subpopulation of B lymphocytes and platelet-rich plasma of classical scrapie infected sheep using a sheep bioassay. Combining platelets with B lymphocytes might enhance PrPSc detection levels in blood samples.

  7. Trajectory of platelets in pregnancy - do low-risk women need an intrapartum full blood count prior to epidural?

    Science.gov (United States)

    Duong, Christine; Kidson-Gerber, Giselle; Peters, Nancy; Listijono, Dave R; Henry, Amanda

    2015-10-01

    This study aimed to investigate whether pregnant women with a normal 28-week gestation platelet count and no high-risk conditions for thrombocytopenia require a pre-epidural platelet count. All 1844 included women (platelet count > 150 × 10(9) /L at 28 weeks' gestation, term singleton birth, no thrombocytopenia risk conditions) had a platelet count > 100 × 10(9) /L prebirth, suggesting low-risk pregnant women do not require pre-epidural full blood count solely to check platelet count.

  8. Blood platelet production with breaks : optimization by SDP and simulation

    NARCIS (Netherlands)

    Haijema, Rene; van Dijk, Nico; van der Wal, Jan; Sibinga, Cees Smit

    2009-01-01

    The production and inventory management of blood products at blood banks and hospitals is it problem of general human interest. As a shortage may put lives at risk, shortages are to be kept to a minimum. As the supply is voluntary and costly, any spill of unused blood (products) is also to be minimi

  9. Response of blood platelets to resveratrol during a model of hyperhomocysteinemia.

    Science.gov (United States)

    Malinowska, Joanna; Olas, Beata

    2011-01-01

    Resveratrol (3,4',5-trihydroxystilben), a phenolic antioxidant synthesized in grapes and other plants, and also present in wine, has been suggested to help prevent cardiovascular events. In this study the influence of resveratrol on platelet aggregation during a model of hyperhomocysteinemia was investigated. We induced hyperhomocysteinemia using a reduced form of Hcys (final dose, 0.1 mM) and the most reactive form of Hcys, its cyclic thioester, homocysteine thiolactone (HTL, 1 µM). The aim of our study in vitro was also to investigate superoxide anion radical (O(2)(-)) generation after incubation of platelets with Hcys, HTL, and resveratrol. We have observed that HTL, like its precursor Hcys, stimulated the generation of (O(2)(-) in platelets and caused an augmentation of platelet aggregation induced by the strong physiological agonist thrombin. Our results in vitro also demonstrated that resveratrol reduced the toxic action of Hcys and HTL on blood platelet aggregation and superoxide anion radical production in platelets, suggesting its potential protective effects on hemostasis are negatively influenced by homocysteine and its derivatives.

  10. Effects of halopemide, a new psychotropic agent, on the uptake of serotonin by blood platelets

    NARCIS (Netherlands)

    Loonen, A.J.M.; Soudijn, W.

    1979-01-01

    The influence of halopemide, a new psychotropic agent, and some putative metabolites on the uptake of14C-5-HT into blood platelets of rat and man were studied and compared to the effects of imipramine, sulpiride and clozapine. Halopemide, its putative metabolites R 38570 and R 29676 and sulpiride in

  11. Dauricoside, a new glycosidal alkaloid having an inhibitory activity against blood-platelet aggregation.

    Science.gov (United States)

    Hu, S M; Xu, S X; Yao, X S; Cui, C B; Tezuka, Y; Kikuchi, T

    1993-10-01

    Dauricoside (1), a new glycosidal alkaloid, was isolated from the rhizomes of Menispermum dauricum DC. along with dauricine (2), daurisoline (3), dauriporphine (4), menisporphine (5), and 6-O-demethylmenisporphine (6), and its structure was determined by means of spectroscopic methods. Compounds 1, 2, and 3 inhibited blood-platelet aggregation induced by adenosine 5'-diphosphate (ADP).

  12. Effect of n-tyrosol on blood viscosity and platelet aggregation.

    Science.gov (United States)

    Plotnikov, M B; Chernysheva, G A; Smol'yakova, V I; Maslov, M Yu; Cherkashina, I V; Krysin, A P; Sorokina, I V; Tolstikova, T G

    2007-01-01

    Experiments on rats showed that n-tyrosol limited the increase in blood viscosity during thermal exposure at a shear rate of 5-300 sec(-1) and inhibited ADP-induced platelet aggregation. The effects of n-tyrosol are comparable to that of pentoxyphylline.

  13. Homocysteine and its thiolactone-mediated modification of fibrinogen affect blood platelet adhesion.

    Science.gov (United States)

    Malinowska, Joanna; Olas, Beata

    2012-01-01

    Homocysteine (Hcys) and homocysteine thiolactone (HTL) concentrations in organism are correlated with a number of serious pathologies. In the literature, there are few papers describing studies on the effects of homocysteine on proteins that participate in blood coagulation and fibrinolysis in human. However, mechanisms involved in the relationship between hyperhomocysteinemia and hemostatic process are still unclear. The role of N- or S-homocysteinylation (induced by Hcys and its derivatives) of different hemostatic proteins, including fibrinogen is also still poorly known. The aim of this study was to establish the functional changes of the fibrinogen molecule induced by Hcys (at final doses of 10-100 µM) and the most reactive form of Hcys - its cyclic thioester, homocysteine thiolactone (0.1-1 µM), and to examine the effects of these changes on the capability of fibrinogen to interact with human blood platelets (by measuring the platelet adhesion). Our present results demonstrated that Hcys-treated fibrinogen in comparison with native molecule had a distinct capability to mediate platelet adhesion. Both, unstimulated and thrombin-activated platelets showed a reduced ability to adhere to Hcys-mediated fibrinogen. HTL (at all tested concentrations) had similar properties when we used thrombin-activated platelets. In conclusion, the results reported in this study could be useful for a better understanding of changes in hemostasis during hyperhomocysteinemia.

  14. Changes in white blood cells and platelets in children with falciparum malaria: relationship to disease outcome.

    Science.gov (United States)

    Ladhani, Shamez; Lowe, Brett; Cole, Andrew O; Kowuondo, Ken; Newton, Charles R J C

    2002-12-01

    Little is known about the changes in white blood cells and platelets in children with falciparum malaria in endemic areas. We measured the white cell count (WCC) and platelets of 230 healthy children from the community, 1369 children admitted to hospital with symptomatic malaria, and 1461 children with other medical conditions. Children with malaria had a higher WCC compared with community controls, and leucocytosis was strongly associated with younger age, deep breathing, severe anaemia, thrombocytopenia and death. The WCC was not associated with a positive blood culture. In children with malaria, high lymphocyte and low monocyte counts were independently associated with mortality. A platelet count of less than 150 x 109/l was found in 56.7% of children with malaria, and was associated with age, prostration and parasite density, but not with bleeding problems or mortality. The mean platelet volume was also higher in children with malaria compared with other medical conditions. This may reflect early release from the bone marrow in response to peripheral platelet destruction. Thus, leucocytosis was associated with both severity and mortality in children with falciparum malaria, irrespective of bacteraemia, whereas thrombocytopenia, although very common, was not associated with adverse outcome.

  15. Estimation of platelet count in unstained peripheral blood smears in comparison with stained smears and evaluation of its efficacy.

    Science.gov (United States)

    Umashankar, T; Thomas, B M; Sahana, P

    2014-12-01

    Assessment of platelet count is an important diagnostic parameter in haematology. Automated blood cell counters have largely replaced the manual method. However, all abnormal platelet counts are verified in Leishman's stained peripheral blood smear. Platelets also can be identified in the unstained blood smears. The objective of this study is to compare the unstained peripheral blood smears with the stained smears and determination of the effectiveness of unstained smears in the estimation of platelet count. 250 Venous blood samples sent for blood cell counts were analyzed. Platelets were counted in the unstained smear under 100× objective in 10 fields without placing immersion oil and the average number of platelets was calculated. Same smear was stained by Leishman's stain and platelets were counted under 100× objective after placing a drop of immersion oil. Collected data were analyzed for intra-class correlation coefficient (ICC). ICC showed excellent agreement (ICC > 0.85). The unstained smears were found to be as effective as stained smears for platelet count in most of the cases. However, in case of doubt a stained preparation has to be made to confirm the count. The turnaround time was 3-5 minutes compared to 15-20 minutes by stained smear technique, thus this technique may be used as an initial screening method whenever there is large sample load.

  16. I am the 9%: Making the case for whole-blood platelets.

    Science.gov (United States)

    Seheult, J N; Triulzi, D J; Yazer, M H

    2016-06-01

    Over the last 15 years, there has been a trend in the United States towards the increasing use of apheresis platelet (AP) concentrates over whole-blood-derived platelets (WBP). Although 1-h- and 24-h-corrected count increments tend to be higher with AP, this does not translate into improved haemostatic efficiency when used to prevent bleeding in haematology/oncology patients. WBP expose the recipient to more donors than apheresis products. However, recent studies have shown no significant differences in the rates of bacterial contamination, human leukocyte antigen alloimmunisation, RhD alloimmunisation, transfusion-related acute lung injury or febrile non-haemolytic transfusion reactions between these two products. Given the overall low rates of virally contaminated units in the era of nucleic acid testing and rigorous donor screening, the difference in donor exposures of 4-6 vs 1 has minimal clinical relevance. Although studies point to a marginally increased risk of donor adverse events associated with WBP, the absolute risk is too miniscule to act as a deterrent to making whole-blood donations. Both types of platelet concentrates should therefore be considered clinically equivalent; in this light, the most responsible use of the community donor resource pool, which both optimises the utility of a whole-blood donation and meets the clinical needs of thrombocytopenic recipients, is to have a mix of both types of platelet products so as to mitigate the risk of shortages.

  17. The multifunctionality of berries toward blood platelets and the role of berry phenolics in cardiovascular disorders.

    Science.gov (United States)

    Olas, Beata

    2016-10-25

    Diet and nutrition have an important influence on the prophylaxis and progression of cardiovascular disease; one example is the inhibition of blood platelet functions by specific components of fruits and vegetables. Garlic, onion, ginger, dark chocolate and polyunsaturated fatty acids all reduce blood platelet aggregation. A number of fruits contain a range of cardioprotective antioxidants and vitamins, together with a large number of non-nutrient phytochemicals such as phenolic compounds, which may possess both antioxidant properties and anti-platelet activity. Fresh berries and berry extracts possess high concentrations of phenolic compounds, i.e. phenolic acid, stilbenoids, flavonoids and lignans. The aim of this review article is to provide an overview of current knowledge of the anti-platelet activity of berries, which form an integral part of the human diet. It describes the effects of phenolic compounds present in a number of berries, i.e. black chokeberries - aronia berries (Aronia melanocarpa), blueberries (Vaccinium myrtillus), cranberries (Vaccinium sect. Oxycoccus), sea buckthorn berries (Hippophae rhamnoides) and grapes (Vitis), as well as various commercial products from berries (i.e. juices), on platelets and underlying mechanisms. Studies show that the effects of berries on platelet activity are dependent on not only the concentrations of the phenolic compounds in the berries or the class of phenolic compounds, but also the types of berry and the form (fresh berry, juice or medicinal product). Different results indicate that berries may play a role in the prevention of cardiovascular disorders, but the development of well-controlled clinical studies with berries is encouraged.

  18. Platelet-neutrophil complex formation-a detailed in vitro analysis of murine and human blood samples.

    Science.gov (United States)

    Mauler, Maximilian; Seyfert, Julia; Haenel, David; Seeba, Hannah; Guenther, Janine; Stallmann, Daniela; Schoenichen, Claudia; Hilgendorf, Ingo; Bode, Christoph; Ahrens, Ingo; Duerschmied, Daniel

    2016-05-01

    Platelets form complexes with neutrophils during inflammatory processes. These aggregates migrate into affected tissues and also circulate within the organism. Several studies have evaluated platelet-neutrophil complexes as a marker of cardiovascular diseases in human and mouse. Although multiple publications have reported platelet-neutrophil complex counts, we noticed that different methods were used to analyze platelet-neutrophil complex formation, resulting in significant differences, even in baseline values. We established a protocol for platelet-neutrophil complex measurement with flow cytometry in murine and human whole blood samples. In vitro platelet-neutrophil complex formation was stimulated with ADP or PMA. We tested the effect of different sample preparation steps and cytometer settings on platelet-neutrophil complex detection and noticed false-positive counts with increasing acquisition speed. Platelet-neutrophil complex formation depends on platelet P-selectin expression, and antibody blocking of P-selectin consequently prevented ADP-induced platelet-neutrophil complex formation. These findings may help generating more comparable data among different research groups that examine platelet-neutrophil complexes as a marker for cardiovascular disease and novel therapeutic interventions.

  19. DYNAMIC MODEL AND SIMULATION OF THE PLATELETS' ROLE IN BLOOD COAGULATION

    Institute of Scientific and Technical Information of China (English)

    许传青; 曾衍钧; Hans Grgersen

    2002-01-01

    In order to confirm which process is the most important in the blood coagulation cascade, a dynamic model on the function of platelets in blood coagulation is presented based on biochemical experiments. Based on qualitative analysis and mathematical simulation, a series of conclusions about the influence of the activation rate of factor Ⅷ and factor Ⅸ on the generation of thrombin (Ⅱa) are drawn. It is evident that the pro-coagulation stimulus must exceed a threshold value to initiate the coagulation cascade. The value is related to the binding constant d2 of the platelet.The stability of the equilibrium value is also related to the pro-coagulation stimulus.This article also evaluates the influence of the stimulus strength and the activated rate parameter of platelets on thrombin. The proportion of platelets activated at any given time is designated c. To each c, we obtain a maximum concentration of thrombin. It is evident that when the level of factor IX is below 1% of the normal level, the rate of thrombin generation reduces dramatically, resulting in severe bleeding tendency.

  20. Interaction of nanoparticles of ferric oxide with brain nerve terminals and blood platelets

    Science.gov (United States)

    Borisova, Tatiana; Krisanova, Natalia; Sivko, Roman; Borisov, Arseniy

    2012-07-01

    Nanoparticles of ferric oxide are the components of Lunar and Martian soil simulants. The observations suggest that exposure to Lunar soli simulant can be deleterious to human physiology and the components of lunar soil may be internalized by lung epithelium and may overcome the blood-brain barrier. The study focused on the effects of nanoparticles of ferric oxide on the functional state of rat brain nerve terminals (synaptosomes) and rabbit blood platelets. Using photon correlation spectroscopy, we demonstrated the binding of nanoparticles of ferric oxide with nerve terminals and platelets. Nanoparticles did not depolarize the plasma membrane of nerve terminals and platelets that was shown by fluorimetry with potential-sensitive fluorescent dye rhodamine 6G. Using pH-sensitive fluorescent dye acridine orange, we revealed that the acidification of synaptic vesicles of nerve terminals and secretory granules of platelets did not change in the presence of nanoparticles. The initial velocity of uptake of excitatory neurotransmitter glutamate was not influenced by nanoparticles of ferric oxide, whereas glutamate binding to nerve terminals was altered. Thus, it was suggested that nanoparticles of ferric oxide might disturb glutamate transport in the mammalian CNS.

  1. Physiopathology of blood platelets and development of platelets substitutes. Progress report, August 1, 1976--October 31, 1977. [/sup 51/Cr

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, M G

    1977-07-31

    Progress is reported on the following research projects: the effect of estrogen on platelet aggregability and thrombus formation; the antithrombotic effect of platelet inhibiting agents in a bench model of artificial kidney; the arrest of hemorrhage in severely alloimmunized thrombocytopenic patients; and in vivo elution of /sup 51/Cr from labeled platelets induced by antibody. (HLW)

  2. Manipulation of oxygenation and flow-induced shear stress can increase the in vitro yield of platelets from cord blood.

    Science.gov (United States)

    Lasky, Larry C; Sullenbarger, Brent

    2011-11-01

    A method to produce clinically useful platelets in vitro would help overcome the frequent shortages, donor deferrals, disease transmission, and alloimmunization with volunteer donor-derived platelets. Using CD34 positively selected cord blood cells, we investigated ways to increase platelet quality and yield in a three-dimensional modular perfusion bioreactor system. We found a two- to threefold increase in platelet numbers produced only when the early phases of the culture process were carried out at 5% oxygen, versus when 20% oxygen was used throughout the culture period (pplatelets increased two- to threefold (pplatelet production from proplatelets. The use of altered oxygen levels and cross flow enhanced platelet numbers and quality, and will contribute to eventual in vitro platelet production for clinical use.

  3. Inhibition of glutamate receptors reduces the homocysteine-induced whole blood platelet aggregation but does not affect superoxide anion generation or platelet membrane fluidization.

    Science.gov (United States)

    Karolczak, Kamil; Pieniazek, Anna; Watala, Cezary

    2017-01-01

    Homocysteine (Hcy) is an excitotoxic amino acid. It is potentially possible to prevent Hcy-induced toxicity, including haemostatic impairments, by antagonizing glutaminergic receptors. Using impedance aggregometry with arachidonate and collagen as platelet agonists, we tested whether the blockade of platelet NMDA (N-methyl-D-aspartate), AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and kainate receptors with their inhibitors: MK-801 (dizocilpine hydrogen maleate, [5R,10S]-[+]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine), CNQX (7-nitro-2,3-dioxo-1,4-dihydroquinoxaline-6-carbonitrile) and UBP-302 (2-{[3-[(2S)-2-amino-2-carboxyethyl]-2,6-dioxo-3,6-dihydropyrimidin 1(2H)-yl]methyl}benzoic acid) may hamper Hcy-dependent platelet aggregation. All the tested compounds significantly inhibited Hcy-augmented aggregation of blood platelets stimulated either with arachidonate or collagen. Hcy stimulated the generation of superoxide anion in whole blood samples in a concentration-dependent manner; however, this process appeared as independent on ionotropic glutamate receptors, as well as on NADPH oxidase and protein kinase C, and was not apparently associated with the extent of either arachidonate- or collagen-dependent platelet aggregation. Moreover, Hcy acted as a significant fluidizer of surface (more hydrophilic) and inner (more hydrophobic) regions of platelet membrane lipid bilayer, when used at the concentration range from 10 to 50 µmol/l. However, this effect was independent on the Hcy action through glutamate ionotropic receptors, since there was no effects of MK-801, CNQX or UBP-302 on Hcy-mediated membrane fluidization. In conclusion, Hcy-induced changes in whole blood platelet aggregation are mediated through the ionotopic excitotoxic receptors, although the detailed mechanisms underlying such interactions remain to be elucidated.

  4. Nucleation of platelets with blood-borne pathogens on Kupffer cells precedes other innate immunity and contributes to bacterial clearance.

    Science.gov (United States)

    Wong, Connie H Y; Jenne, Craig N; Petri, Björn; Chrobok, Navina L; Kubes, Paul

    2013-08-01

    Through the use of intravital imaging of the liver, we demonstrate a collaborative role for platelets with Kupffer cells (KCs) in eradicating blood-borne bacterial infection. Under basal conditions, platelets, via the platelet-adhesion receptor GPIb, formed transient 'touch-and-go' interactions with von Willebrand factor (vWF) constitutively expressed on KCs. Bacteria such as Bacillus cereus and methicillin-resistant Staphylococcus aureus (MRSA) were rapidly caught by KCs and triggered platelets to switch from 'touch-and-go' adhesion to sustained GPIIb-mediated adhesion on the KC surface to encase the bacterium. Infected GPIbα-deficient mice had more endothelial and KC damage than did their wild-type counterparts, which led to more fluid leakage, substantial polycythemia and rapid mortality. Our study identifies a previously unknown surveillance mechanism by which platelets survey macrophages that rapidly converts to a critical host response to blood-borne bacteria.

  5. Variation of Red Blood Cell Distribution Width and Mean Platelet Volume after Moderate Endurance Exercise

    Directory of Open Access Journals (Sweden)

    Giuseppe Lippi

    2014-01-01

    Full Text Available Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217±32 min/week who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC, reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV; mean corpuscular hemoglobin (MCH; reticulocyte haemoglobin content (Ret CHR; RBC distribution width (RDW, mean platelet volume (MPV. No significant variations were observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These results may have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDW and MPV may be significantly associated with cardiovascular disease.

  6. Antioxidative properties of curcumin in the protection of blood platelets against oxidative stress in vitro.

    Science.gov (United States)

    Kolodziejczyk, Joanna; Olas, Beata; Saluk-Juszczak, Joanna; Wachowicz, Barbara

    2011-01-01

    The present in vitro study was designed to estimate the antioxidative activity of curcumin in the protection of human blood platelets and plasma against peroxynitrite (ONOO(-))-induced oxidative stress. The effects of curcumin (12.5-50 µg/ml) on ONOO(-)-induced damage of proteins and lipids were determined by the estimation of protein carbonyl groups, 3-nitrotyrosine formation, and thiobarbituric acid reactive substance (TBARS) generation. Exposure of blood platelets and plasma to 100 µM ONOO(-) resulted in an increased level of carbonyl groups, nitration of protein tyrosine residues, and enhanced lipid peroxidation. Curcumin inhibited carbonyl group formation in plasma and in platelet proteins. The highest dose of curcumin (50 µg/ml) reduced blood platelet protein carbonylation by approximately 40%. In the protection of blood plasma protein, the lower doses of curcumin (12.5 and 25 µg/ml) were more effective. Curcumin partially prevented 3-nitrotyrosine formation in plasma proteins; the effect of curcumin was only statistically significant in blood platelets at the highest dose (50 µg/ml). The antioxidative action of curcumin in the protection against lipid peroxidation caused by ONOO(-) was also observed. Curcumin suppressed the formation of TBARS both in blood platelets and in plasma samples. The highest concentration of curcumin (50 µg/ml) decreased the TBARS level by approximately 35% in both blood platelets and plasma samples. In conclusion, the present study demonstrates the antioxidative properties of curcumin and its protective effects against oxidative/nitrative changes of blood platelets and plasma components, especially proteins and lipids.

  7. Platelet matching for alloimmunized patients

    Institute of Scientific and Technical Information of China (English)

    S H.Hsu

    2010-01-01

    @@ Platelets play an essential role in blood coagulation,hemostasis and maintenance of vascular integrity.Platelets are utilized primarily to prevent or treat bleeding in thrombocytopenic patients and patients with impaired platelet production in the bone marrow and/or with dysfunctional platelets.In current practice,platelet transfusion begins with randomly selected platelet products:either pooled platelets prepared from whole blood derived platelets; or single donor platelets prepared by apheresis procedures.

  8. Shape changes induced by biologically active peptides and nerve growth factor in blood platelets of rabbits.

    Science.gov (United States)

    Gudat, F; Laubscher, A; Otten, U; Pletscher, A

    1981-11-01

    1 Nerve growth factor (NGF), substance P (SP) and thymopoietin all caused shape change reactions of rapid onset in rabbit platelets. NGF had the highest maximal effect, and SP the lowest EC50 (concentration causing half maximal shape change). The action of SP was reversible within 5 min, whereas that of NGF lasted for at least 1 h. A series of other peptides were inactive. 2 After preincubation of platelets with SP, a second application of SP no longer caused a shape change reaction, whereas the effect of NGF was not influenced. 3 An oxidized NGF-derivative without biological activity did not cause a shape change reaction, neither did epidermal growth factor. 4 Prostaglandin E1 (PGE1) and pretreatment of the platelets with 3% butanol, which counteract the shape changes caused by 5-hydroxytryptamine (5-HT) and adenosine 3',5'-diphosphate, also antagonized those induced by NGF and SP. Neither heparin nor methysergide, an antagonist of 5-HT-receptors, influenced the shape change induced by NGF or SP. The action of NGF was also antagonized by a specific antibody to NGF. 5 Thymopoietin, like the basic polypeptide polyornithine (mol. wt. 40,000) was not antagonized by PGE1 and butanol. Heparin, which counteracted the effect of polyornithine, did not influence that of thymopoietin. 6 In conclusion, different modes of action are involved in the shape change of blood platelets induced by polypeptides and proteins. SP and NGF may act by stimulating specific membrane receptors.

  9. Hippophae rhamnoides L. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma.

    Science.gov (United States)

    Olas, Beata; Kontek, Bogdan; Malinowska, Paulina; Żuchowski, Jerzy; Stochmal, Anna

    2016-01-01

    Effects of the phenolic fraction from Hippophae rhamnoides fruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation) and the generation of superoxide anion (O2 (-∙)) in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin) were studied in vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2) or H2O2/Fe (a donor of hydroxyl radicals). The tested fraction of H. rhamnoides (0.5- 50 µg/mL; the incubation time: 15 and 60 min) inhibited lipid peroxidation induced by H2O2 or H2O2/Fe. The H. rhamnoides phenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2 or H2O2/Fe. Moreover, the level of O2 (-∙) in platelets significantly decreased. In comparative experiments, the H. rhamnoides fraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL). The obtained results suggest that H. rhamnoides fruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.

  10. Hippophae rhamnoides L. Fruits Reduce the Oxidative Stress in Human Blood Platelets and Plasma

    Directory of Open Access Journals (Sweden)

    Beata Olas

    2016-01-01

    Full Text Available Effects of the phenolic fraction from Hippophae rhamnoides fruits on the production of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation and the generation of superoxide anion (O2-∙ in human blood platelets (resting platelets and platelets stimulated by a strong physiological agonist, thrombin were studied in vitro. We also examined antioxidant properties of this fraction against human plasma lipid peroxidation and protein carbonylation induced by a strong biological oxidant, hydrogen peroxide (H2O2 or H2O2/Fe (a donor of hydroxyl radicals. The tested fraction of H. rhamnoides (0.5– 50 µg/mL; the incubation time: 15 and 60 min inhibited lipid peroxidation induced by H2O2 or H2O2/Fe. The H. rhamnoides phenolic fraction inhibited not only plasma lipid peroxidation, but also plasma protein carbonylation stimulated by H2O2 or H2O2/Fe. Moreover, the level of O2-∙ in platelets significantly decreased. In comparative experiments, the H. rhamnoides fraction was a more effective antioxidant than aronia extract or grape seed extract (at the highest tested concentration, 50 µg/mL. The obtained results suggest that H. rhamnoides fruits may be a new, promising source of natural compounds with antioxidant and antiplatelet activity beneficial not only for healthy people, but also for those with oxidative stress-associated diseases.

  11. A multiple time stepping algorithm for efficient multiscale modeling of platelets flowing in blood plasma

    Science.gov (United States)

    Zhang, Peng; Zhang, Na; Deng, Yuefan; Bluestein, Danny

    2015-03-01

    We developed a multiple time-stepping (MTS) algorithm for multiscale modeling of the dynamics of platelets flowing in viscous blood plasma. This MTS algorithm improves considerably the computational efficiency without significant loss of accuracy. This study of the dynamic properties of flowing platelets employs a combination of the dissipative particle dynamics (DPD) and the coarse-grained molecular dynamics (CGMD) methods to describe the dynamic microstructures of deformable platelets in response to extracellular flow-induced stresses. The disparate spatial scales between the two methods are handled by a hybrid force field interface. However, the disparity in temporal scales between the DPD and CGMD that requires time stepping at microseconds and nanoseconds respectively, represents a computational challenge that may become prohibitive. Classical MTS algorithms manage to improve computing efficiency by multi-stepping within DPD or CGMD for up to one order of magnitude of scale differential. In order to handle 3-4 orders of magnitude disparity in the temporal scales between DPD and CGMD, we introduce a new MTS scheme hybridizing DPD and CGMD by utilizing four different time stepping sizes. We advance the fluid system at the largest time step, the fluid-platelet interface at a middle timestep size, and the nonbonded and bonded potentials of the platelet structural system at two smallest timestep sizes. Additionally, we introduce parameters to study the relationship of accuracy versus computational complexities. The numerical experiments demonstrated 3000x reduction in computing time over standard MTS methods for solving the multiscale model. This MTS algorithm establishes a computationally feasible approach for solving a particle-based system at multiple scales for performing efficient multiscale simulations.

  12. Effect of simvastatin combined amlodipine besylate on blood rheology and platelet activation in elderly patients with hypertension complicated with hyperlipemia

    Institute of Scientific and Technical Information of China (English)

    Ming-Zheng Jiang; Li Qiong; Hui Liu

    2016-01-01

    Objective:To investigate the effect of simvastatin combined amlodipine besylate on blood rheology and platelet activation in elderly patients with hypertension complicated with hyperlipemia.Methods: A total of 200 elderly patients with hypertension complicated with hyperlipemia were divided into hypertension group (n=64), hyperlipemia group (n=71) and combined (hypertension complicated with hyperlipemia) group (n=65). And alternate period health check-up 100 cases were selected as control group. The hypertension group was treated with amlodipine besylate monotherapy, hyperlipidemia group with simvastatin monotherapy, combined group received simvastatin combined with amlodipine besylate treatment, patients of three groups were treated for 12 weeks. Blood rheology and platelet activation before and after treatment were compared.Results: After treatment, blood pressure was significantly lower than that before treatment in hypertension and combined group (P<0.05), and the combined group reduced more significantly (P<0.05), blood fat was significantly lower than that before treatment in hyperlipemia and combined group (P<0.05), and combined group reduced more significantly (P<0.05); Before treatment, indexes of blood rheology (high shear whole blood viscosity, low shear whole blood viscosity, plasma viscosity, fibrinogen and platelet activation index (CD62p and CD63) of three groups were significantly higher than those in control group (P<0.05), and the combined group was increased more significantly than hypertension and hyperlipidemia group (P<0.05); After treatment, blood rheology (high shear whole blood viscosity, low shear whole blood viscosity, plasma viscosity, fibrinogen) and platelet activation index (CD62p and CD63) of hyperlipidemia group and combined group were significantly lower than before treatment (P<0.05), and the reduction combined group were more significant in amplitude (P<0.05).Conclusions: Simvastatin combined amlodipine besylate therapy can

  13. The extract from hop cones (Humulus lupulus) as a modulator of oxidative stress in blood platelets.

    Science.gov (United States)

    Olas, Beata; Kolodziejczyk, Joanna; Wachowicz, Barbara; Jędrejek, Dariusz; Stochmal, Anna; Oleszek, Wiesław

    2011-01-01

    The plant Humulus lupulus is known as the raw material of the brewing industry. Hop cones, rich in polyphenolic compounds and acyl phloroglucides, are widely used to preserve beer and to give it a characteristic aroma and flavor. Hop cones have long been used for medicinal purposes. In particular, hop preparations were mainly recommended for the treatment of sleeping disorders. The antioxidative action of hop cones, however, is poorly understood. The aim of our present study was to investigate in vitro changes in human blood platelets induced by peroxynitrite (ONOO(-), the compound of particular importance for vascular thrombosis and inflammatory process) in the presence of hop cone extract (Humulus lupulus). The antioxidative action of the extract was also compared with the properties of a well-characterized antioxidative commercial monomeric polyphenol, resveratrol (3,4',5-trihydroxystilbene) in a model system in vitro. Various biomarkers of oxidative/nitrative stress, such as carbonyl groups, 3-nitrotyrosine and thiobarbituric acid reactive substances (TBARS) were estimated. The 3-nitrotyrosine formation and carbonyl group generation was assessed by the use of a competition ELISA test and ELISA test, respectively. Tested plant extract (12.5-50 µg/ml), like resveratrol, significantly inhibited protein carbonylation and nitration in the blood platelets treated with ONOO(-) (0.1 mM). The extract from hop cones, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by ONOO(-). The present results indicate that the hope cone extract has in vitro protective effects against ONOO(-), such as induced oxidative/nitrative damage to the human platelet proteins and lipids. However, in comparative studies the extract was not found to be a more effective antioxidant than the solution of pure resveratrol.

  14. Proteomic methodological recommendations for studies involving human plasma, platelets, and peripheral blood mononuclear cells.

    Science.gov (United States)

    de Roos, Baukje; Duthie, Susan J; Polley, Abigael C J; Mulholland, Francis; Bouwman, Freek G; Heim, Carolin; Rucklidge, Garry J; Johnson, Ian T; Mariman, Edwin C; Daniel, Hannelore; Elliott, Ruan M

    2008-06-01

    This study was designed to develop, optimize and validate protocols for blood processing prior to proteomic analysis of plasma, platelets and peripheral blood mononuclear cells (PBMC) and to determine analytical variation of a single sample of depleted plasma, platelet and PBMC proteins within and between four laboratories each using their own standard operating protocols for 2D gel electrophoresis. Plasma depleted either using the Beckman Coulter IgY-12 proteome partitioning kit or the Amersham albumin and IgG depletion columns gave good quality gels, but reproducibility appeared better with the single-use immuno-affinity column. The use of the Millipore Filter Device for protein concentration gave a 16% ( p appears as a single abundant spot. The average within-laboratory coefficient of variation (CV) for each of the matched spots after automatic matching using either PDQuest or ProteomWeaver software ranged between 18 and 69% for depleted plasma proteins, between 21 and 55% for platelet proteins, and between 22 and 38% for PBMC proteins. Subsequent manual matching improved the CV with on average between 1 and 16%. The average between laboratory CV for each of the matched spots after automatic matching ranged between 4 and 54% for depleted plasma proteins, between 5 and 60% for platelet proteins, and between 18 and 70% for PBMC proteins. This variation must be considered when designing sufficiently powered studies that use proteomics tools for biomarker discovery. The use of tricine in the running buffer for the second dimension appears to enhance the resolution of proteins especially in the high molecular weight range.

  15. Compartmentalisation of cAMP-dependent signalling in blood platelets: The role of lipid rafts and actin polymerisation.

    Science.gov (United States)

    Raslan, Zaher; Naseem, Khalid M

    2015-01-01

    Prostacyclin (PGI2) inhibits blood platelets through the activation of membrane adenylyl cyclases (ACs) and cyclic adenosine 3',5'-monophosphate (cAMP)-mediated signalling. However, the molecular mechanism controlling cAMP signalling in blood platelet remains unclear, and in particular how individual isoforms of AC and protein kinase A (PKA) are coordinated to target distinct substrates in order to modulate platelet activation. In this study, we demonstrate that lipid rafts and the actin cytoskeleton may play a key role in regulating platelet responses to cAMP downstream of PGI2. Disruption of lipid rafts with methyl-beta-cyclodextrin (MβCD) increased platelet sensitivity to PGI2 and forskolin, a direct AC cyclase activator, resulting in greater inhibition of collagen-stimulated platelet aggregation. In contrast, platelet inhibition by the direct activator of PKA, 8-CPT-6-Phe-cAMP was unaffected by MβCD treatment. Consistent with the functional data, lipid raft disruption increased PGI2-stimulated cAMP formation and proximal PKA-mediated signalling events. Platelet inhibition, cAMP formation and phosphorylation of PKA substrates in response to PGI2 were also increased in the presence of cytochalasin D, indicating a role for actin cytoskeleton in signalling in response to PGI2. A potential role for lipid rafts in cAMP signalling is strengthened by our finding that a pool of ACV/VI and PKA was partitioned into lipid rafts. Our data demonstrate partial compartmentalisation of cAMP signalling machinery in platelets, where lipid rafts and the actin cytoskeleton regulate the inhibitory effects induced by PGI2. The increased platelet sensitivity to cAMP-elevating agents signalling upon raft and cytoskeleton disruption suggests that these compartments act to restrain basal cAMP signalling.

  16. Effect of the crude extract of Cestrum parqui on carrageenin-induced rat paw oedema and aggregation of human blood platelets.

    Science.gov (United States)

    Shehnaz, D; Hamid, F; Baqai, F T; Uddin Ahmad, V

    1999-08-01

    An extract of Cestrum parqui aerial parts in methanol:water (1:1) showed inhibition of carrageenin-induced oedema. The aggregation of human blood platelets induced by adenosine diphosphate and platelet activating factor was also inhibited (IC(50)s were 3 and 2 mg/mL, respectively). On the contrary, the extract did not inhibit arachidonic acid-mediated platelet aggregation.

  17. Extracts from Trifolium pallidum and Trifolium scabrum aerial parts as modulators of blood platelet adhesion and aggregation.

    Science.gov (United States)

    Kolodziejczyk-Czepas, Joanna; Olas, Beata; Malinowska, Joanna; Wachowicz, Barbara; Szajwaj, Barbara; Kowalska, Iwona; Oleszek, Wieslaw; Stochmal, Anna

    2013-01-01

    A growing number of reports indicate that some species of clover (Trifolium) may have remarkable medical importance; however, the effects of these plants on blood platelets and hemostasis are inadequately recognized. This work was designed to study the effects of Trifolium pallidum and Trifolium scabrum extracts on the functions of human blood platelets in vitro. Platelet suspensions were preincubated with extracts from aerial parts of T. pallidum (phenolic fraction and clovamide fraction) and T. scabrum (phenolic fraction) at the final concentrations of 12.5, 25, and 50 µg/ml. Then, for platelet activation thrombin (0.1 U/ml), thrombin receptor activating peptide (TRAP; 20 µM), or adenosine diphosphate (ADP; 1 µM) were used. The effects of Trifolium extracts on adhesion of blood platelets to fibrinogen and collagen were determined by enzyme-linked immunosorbent assay (ELISA) method. Platelet aggregation was monitored on a dual-channel Chronolog aggregometer. In these studies, we also compared the action of tested plant extracts with the effects of another antiplatelet plant-derived compound - resveratrol (3,4',5-trihydroxystilbene). The performed assays demonstrated that the tested extracts might influence the platelet functions in vitro. The inhibitory, concentration-dependent effects of all tested extracts on adhesion of thrombin-stimulated platelets to collagen was found. Both extracts from T. pallidum and from T. scabrum reduced the thrombin-induced platelet adhesion to fibrinogen. Furthermore, in the presence of all three extracts, the platelet aggregation induced by thrombin was slightly inhibited. Our results also indicate that the tested plant extracts (at the highest concentrations used of 50 µg/ml), similar to purified resveratrol, inhibit selected steps of platelet activation stimulated by both proteolytic (thrombin) and nonproteolytic agonists (TRAP or ADP). In the comparative studies, T. pallidum and T. scabrum extracts was not found

  18. The effect of protein corona composition on the interaction of carbon nanotubes with human blood platelets.

    Science.gov (United States)

    De Paoli, Silvia H; Diduch, Lukas L; Tegegn, Tseday Z; Orecna, Martina; Strader, Michael B; Karnaukhova, Elena; Bonevich, John E; Holada, Karel; Simak, Jan

    2014-08-01

    Carbon nanotubes (CNT) are one of the most promising nanomaterials for use in medicine. The blood biocompatibility of CNT is a critical safety issue. In the bloodstream, proteins bind to CNT through non-covalent interactions to form a protein corona, thereby largely defining the biological properties of the CNT. Here, we characterize the interactions of carboxylated-multiwalled carbon nanotubes (CNTCOOH) with common human proteins and investigate the effect of the different protein coronas on the interaction of CNTCOOH with human blood platelets (PLT). Molecular modeling and different photophysical techniques were employed to characterize the binding of albumin (HSA), fibrinogen (FBG), γ-globulins (IgG) and histone H1 (H1) on CNTCOOH. We found that the identity of protein forming the corona greatly affects the outcome of CNTCOOH's interaction with blood PLT. Bare CNTCOOH-induced PLT aggregation and the release of platelet membrane microparticles (PMP). HSA corona attenuated the PLT aggregating activity of CNTCOOH, while FBG caused the agglomeration of CNTCOOH nanomaterial, thereby diminishing the effect of CNTCOOH on PLT. In contrast, the IgG corona caused PLT fragmentation, and the H1 corona induced a strong PLT aggregation, thus potentiating the release of PMP.

  19. The increased level of COX-dependent arachidonic acid metabolism in blood platelets from secondary progressive multiple sclerosis patients.

    Science.gov (United States)

    Morel, Agnieszka; Miller, Elzbieta; Bijak, Michal; Saluk, Joanna

    2016-09-01

    Platelet activation is increasingly postulated as a possible component of the pathogenesis of multiple sclerosis (MS), especially due to the increased risk of cardiovascular events in MS. Arachidonic acid cascade metabolized by cyclooxygenase (COX) is a key pathway of platelet activation. The aim of our study was to investigate the COX-dependent arachidonic acid metabolic pathway in blood platelets from secondary progressive multiple sclerosis (SP MS) patients. The blood samples were obtained from 50 patients (man n = 22; female n = 28), suffering from SP MS, diagnosed according to the revised McDonald criteria. Platelet aggregation was measured in platelet-rich plasma after arachidonic acid stimulation. The level of COX activity and thromboxane B2 concentration were determined by ELISA method. Lipid peroxidation was assessed by measuring the level of malondialdehyde. The results were compared with a control group of healthy volunteers. We found that blood platelets obtained from SP MS patients were more sensitive to arachidonic acid and their response measured as platelet aggregation was stronger (about 14 %) relative to control. We also observed a significantly increased activity of COX (about 40 %) and synthesis of thromboxane B2 (about 113 %). The generation of malondialdehyde as a marker of lipid peroxidation was about 10 % higher in SP MS than in control. Cyclooxygenase-dependent arachidonic acid metabolism is significantly increased in blood platelets of patients with SP MS. Future clinical studies are required to recommend the use of low-dose aspirin, and possibly other COX inhibitors in the prevention of cardiovascular risk in MS.

  20. Effect of ginger (Zingiber officinale Rosc.) and fenugreek (Trigonella foenumgraecum L.) on blood lipids, blood sugar and platelet aggregation in patients with coronary artery disease.

    Science.gov (United States)

    Bordia, A; Verma, S K; Srivastava, K C

    1997-05-01

    In a placebo-controlled study the effect of ginger and fenugreek was examined on blood lipids, blood sugar, platelet aggregation, fibrinogen and fibrinolytic activity. The subjects included in this study were healthy individuals, patients with coronary artery disease (CAD), and patients with non-insulin-dependent diabetes mellitus (NIDDM) who either had CAD or were without CAD. In patients with CAD powdered ginger administered in a dose of 4 g daily for 3 months did not affect ADP- and epinephrine-induced platelet aggregation. Also, no change in the fibrinolytic activity and fibrinogen level was observed. However, a single dose of 10 g powdered ginger administered to CAD patients produced a significant reduction in platelet aggregation induced by the two agonists. Ginger did not affect the blood lipids and blood sugar. Fenugreek given in a dose of 2.5 g twice daily for 3 months to healthy individuals did not affect the blood lipids and blood sugar (fasting and post prandial). However, administered in the same daily dose for the same duration to CAD patients also with NIDDM, fenugreek decreased significantly the blood lipids (total cholesterol and triglycerides) without affecting the HDL-c. When administered in the same daily dose to NIDDM (non-CAD) patients (mild cases), fenugreek reduced significantly the blood sugar (fasting and post prandial). In severe NIDDM cases, blood sugar (both fasting and post prandial) was only slightly reduced. The changes were not significant. Fenugreek administration did not affect platelet aggregation, fibrinolytic activity and fibrinogen.

  1. Adhesion of blood platelets under flow to wettability gradient polyethylene surfaces made in a shielded gas plasma

    NARCIS (Netherlands)

    Spijker, HT; Busscher, HJ; Graaff, R; van Oeveren, W; Bos, R.R.M.

    2002-01-01

    Adhesion and activation of platelets are important steps in the thrombosis of blood after contact with a biomaterial surface and are governed, in part, by the wettability of the surface. Since most implanted devices are in contact with blood under flow conditions, it is important to study the effect

  2. The change and significance of platelet parameters and blood coagulation function index in patients with hypertensive disorder complicating pregnancy

    Institute of Scientific and Technical Information of China (English)

    Yu-Xia Shi; Yi-Xin Yang; Qian Xu; Yanhua Zhu

    2015-01-01

    Objective:To explore the change and significance of platelet parameters and blood coagulation function index in patients with hypertensive disorder complicating pregnancy.Methods: Chose 89 patients with HDCP, they were set as HDCP group, chose another 60 cases health late pregnancy women and 42 cases non pregnant female, they were set as late pregnant group and non-pregnant control group, detected the platelet parameters: the average blood platelet count (PLT), platelet volume (MPV), platelet distribution width (PDW) and blood coagulation indexes, plasma prothrombin time (PT), thrombin time (TT), fibrinogen (FIB), D-dimer (D-D), activated partial blood coagulation time (APTT) live enzymes in three groups.Results: (1) Compared with the non-pregnant group and late pregnant group, PLT was significantly lower, while the MPV and PDW were significantly higher in HDCP group; PLT in late pregnant group was significantly lower than that in non-pregnant group, and there were no significantly difference of MPV and PDW in the two groups; (2) Compared with the non-pregnant group and late pregnant group, PT and APTT levels were significantly lower, while FIB and D-D were significantly higher in HDCP group; The level of PT and APTT in late pregnant group were significantly lower, and FIB and D-D levels were significantly higher than that in non-pregnant group, However, The level of TT were no statistical significance difference among the three groups.Conclusion: HDCP existence phenomenon of platelet activation and apparent high coagulation state, dynamic detection of HDCP patients platelet parameters and blood coagulation indexes to prevent related complications, improve obstetrics safety is of great significance.

  3. Activation-dependent surface expression of gC1qR/p33 on human blood platelets.

    Science.gov (United States)

    Peerschke, Ellinor I B; Murphy, Tara K; Ghebrehiwet, Berhane

    2003-02-01

    GC1qR/p33 (gC1qR) is expressed by a variety of somatic and cultured cells, including blood platelets. It interacts with several cellular, viral, bacterial, and plasma proteins, suggesting a potential role in thrombosis, inflammation, and infection. Considerable controversy has surrounded the surface membrane localization of gC1qR, however, since its cDNA sequence does not predict a traditional membrane-anchoring domain, and bears a typical mitochondrial targeting sequence. The present study examined gC1qR expression on resting and activated human blood platelets using flow cytometry and confocal microscopy with two monoclonal antibodies, 74.5.2 and 60.11, directed against gC1qR C-terminal amino acids 204-218, and N-terminal amino acids 76-93, respectively. Unstimulated platelets reacted minimally with either antibody. In contrast, platelet activation with TRAP, epinephrine, or ADP produced markedly increased gC1qR expression as reflected by 74.5.2 binding but not 60.11 binding. Platelet activation was verified using PAC-1 and anti CD 62 antibodies. Whereas PAC-1 binding to activated platelets could be reversed following platelet incubation with PGE1, 74.5.2 binding remained unchanged, suggesting the sustained expression of gC1qR following platelet stimulation. The data further demonstrate that detection of cell surface gC1qR may be dependent on antibody specificity. The ability of gC1qR to bind proteins involved in complement, coagulation, and kinin systems, as well as viral and bacterial pathogens including S. aureus protein A, supports the hypothesis that gC1qR expressed on activated platelets may contribute directly to thrombosis, inflammation, and endovascular infections.

  4. Alkali treatment of microrough titanium surfaces affects macrophage/monocyte adhesion, platelet activation and architecture of blood clot formation

    Directory of Open Access Journals (Sweden)

    V Milleret

    2011-05-01

    Full Text Available Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties. Here, hyperhydrophilic sand-blasted and acid-etched (SBA titanium surfaces were produced by alkali treatment and their responses to partially heparinized whole human blood were analyzed. Blood clot formation, platelet activation and activation of the complement system was analyzed revealing that exposure time between blood and the material surface is crucial as increasing exposure time results in higher amount of activated platelets, more blood clots formed and stronger complement activation. In contrast, the number of macrophages/monocytes found on alkali-treated surfaces was significantly reduced as compared to untreated SBA Ti surfaces. Interestingly, when comparing untreated to modified SBA Ti surfaces very different blood clots formed on their surfaces. On untreated Ti surfaces blood clots remain thin (below 15 mm, patchy and non-structured lacking large fibrin fiber networks whereas blood clots on differentiated surfaces assemble in an organized and layered architecture of more than 30 mm thickness. Close to the material surface most nucleated cells adhere, above large amounts of non-nucleated platelets remain entrapped within a dense fibrin fiber network providing a continuous cover of the entire surface. These findings might indicate that, combined with findings of previous in vivo studies demonstrating that alkali-treated SBA Ti surfaces perform better in terms of osseointegration, a continuous and structured layer of blood components on the blood-facing surface supports later tissue integration of an endosseous implant.

  5. Efficient removal of platelets from peripheral blood progenitor cell products using a novel micro-chip based acoustophoretic platform.

    Directory of Open Access Journals (Sweden)

    Josefina Dykes

    Full Text Available BACKGROUND: Excessive collection of platelets is an unwanted side effect in current centrifugation-based peripheral blood progenitor cell (PBPC apheresis. We investigated a novel microchip-based acoustophoresis technique, utilizing ultrasonic standing wave forces for the removal of platelets from PBPC products. By applying an acoustic standing wave field onto a continuously flowing cell suspension in a micro channel, cells can be separated from the surrounding media depending on their physical properties. STUDY DESIGN AND METHODS: PBPC samples were obtained from patients (n = 15 and healthy donors (n = 6 and sorted on an acoustophoresis-chip. The acoustic force was set to separate leukocytes from platelets into a target fraction and a waste fraction, respectively. The PBPC samples, the target and the waste fractions were analysed for cell recovery, purity and functionality. RESULTS: The median separation efficiency of leukocytes to the target fraction was 98% whereas platelets were effectively depleted by 89%. PBPC samples and corresponding target fractions were similar in the percentage of CD34+ hematopoetic progenitor/stem cells as well as leukocyte/lymphocyte subset distributions. Median viability was 98%, 98% and 97% in the PBPC samples, the target and the waste fractions, respectively. Results from hematopoietic progenitor cell assays indicated a preserved colony-forming ability post-sorting. Evaluation of platelet activation by P-selectin (CD62P expression revealed a significant increase of CD62P+ platelets in the target (19% and waste fractions (20%, respectively, compared to the PBPC input samples (9%. However, activation was lower when compared to stored blood bank platelet concentrates (48%. CONCLUSION: Acoustophoresis can be utilized to efficiently deplete PBPC samples of platelets, whilst preserving the target stem/progenitor cell and leukocyte cell populations, cell viability and progenitor cell colony-forming ability

  6. Comparison of corneal epitheliotrophic capacities among human platelet lysates and other blood derivatives

    Science.gov (United States)

    Huang, Chien-Jung; Sun, Yi-Chen; Christopher, Karen; Pai, Amy Shih-I; Lu, Chia-Ju; Hu, Fung-Rong; Lin, Szu-Yuan; Chen, Wei-Li

    2017-01-01

    Purpose To evaluate the corneal epitheliotropic abilities of two commercialized human platelet lysates (HPLs) and to compare the results with other blood derivatives, including human peripheral serum (HPS) and bovine fetal serum (FBS). Methods In vitro, human corneal epithelial cells were incubated in various concentrations (0%, 3%, 5% and 10%) of blood derivatives. Two commercialized HPLs, including UltraGRO TM (Helios, Atlanta, GA) and PLTMax (Mill Creek, Rochester, MI), were tested and compared with HPS and FBS. Scratch-induced directional wounding assay was performed to evaluate cellular migration. MTS assay was used to evaluate cellular proliferation. Cellular differentiation was examined by scanning electron microscopy, inverted microscopy and transepithelial electrical resistance. Sprague-Dawley rats were used to evaluate the effects of the blood derivatives on corneal epithelial wound healing in vivo. Different blood derivatives were applied topically every 2 hours for 2 days after corneal epithelial debridement. The concentrations of epidermal growth factor (EGF), transforming growth factor -β1 (TGF-β1), fibronectin, platelet-derived growth factor-AB (PDGF-AB), PDGF-BB, and hyaluronic acid in different blood derivatives were evaluated by enzyme-linked immunosorbent assay (ELISA). Results In vitro experiments demonstrated statistically comparable epitheliotropic characteristics in cellular proliferation, migration, and differentiation for the two commercialized HPLs compared to FBS and HPS. Cells cultured without any serum were used as control group. The epitheliotropic capacities were statistically higher in the two commercialized HPLs compared to the control group (p<0.05). Among the different concentrations of blood derivatives, the preparations with 3% yielded better outcomes compared to 5% and 10%. In rats, HPLs also caused improved but not statistically significant wound healing compared to HPS. All the blood derivatives had better wound healing

  7. Effects of garcinol and guttiferone K isolated from Garcinia cambogia on oxidative/nitrative modifications in blood platelets and plasma.

    Science.gov (United States)

    Kolodziejczyk, Joanna; Masullo, Milena; Olas, Beata; Piacente, Sonia; Wachowicz, Barbara

    2009-11-01

    The effects of garcinol and guttiferone K, two polyisoprenylated benzophenones occurring a food plant called Garcinia cambogia, on oxidative/nitrative protein damage (determined by parameters such as levels of protein carbonyl groups and nitrotyrosine residues) in human blood platelets and plasma after treatment with peroxynitrite (ONOO(-)) were studied in vitro. We also investigated the effects of garcinol and guttiferone K on lipid peroxidation in blood platelets and plasma induced by ONOO(-) (100 microM). Exposure of blood platelets or plasma to peroxynitrite (100 microM) resulted in an increased level of carbonyl groups and nitrotyrosine residues in proteins, and an increase of lipid peroxidation measured by the level of thiobarbituric acid reactive species (TBARS). In the presence of garcinol and guttiferone K (0.1-25 microg/ml), a distinct reduction in the formation of carbonyl groups in plasma and platelet proteins together with the decrease of TBARS caused by 100 microM peroxynitrite, was observed. However, garcinol and guttiferone K did not inhibit plasma and platelet protein nitration induced by peroxynitrite. Polyisoprenylated benzophenones present in human diet such as garcinol or guttiferone K in vitro have protective effects against lipid and protein oxidation and may have some promising effects in vivo because they are good antioxidants in the tested models in vitro. Garcinol and guttiferone K can be also useful as protecting factors against diseases associated with oxidative stress.

  8. Validation of a P2Y12-receptor specific whole blood platelet aggregation assay.

    Science.gov (United States)

    Amann, Michael; Ferenc, Miroslaw; Valina, Christian M; Bömicke, Timo; Stratz, Christian; Leggewie, Stefan; Trenk, Dietmar; Neumann, Franz-Josef; Hochholzer, Willibald

    2016-11-01

    Testing of P2Y12-receptor antagonist effects can support clinical decision-making. However, most platelet function assays use only ADP as agonist which is not P2Y12-receptor specific. For this reason P2Y12-receptor specific assays have been developed by adding prostaglandin E1 (PGE1) to reduce ADP-induced platelet activation via the P2Y1-receptor. The present study sought to evaluate a P2Y12-receptor specific assay for determination of pharmacodynamic and clinical outcomes. This study enrolled 400 patients undergoing coronary stenting after loading with clopidogrel or prasugrel. ADP-induced platelet reactivity was assessed by whole blood aggregometry at multiple time points with a standard ADP assay (ADPtest) and a P2Y12-receptor specific assay (ADPtest HS, both run on Multiplate Analyzer, Roche Diagnostics). Patients were clinically followed for 1 month and all events adjudicated by an independent committee. In total, 2084 pairs of test results of ADPtest and ADPtest HS were available showing a strong correlation between results of both assays (r = 0.96, p < 0.001). These findings prevailed in multiple prespecified subgroups (e.g., age; body mass index; diabetes). Calculated cutoffs for ADPtest HS and the established cutoffs of ADPtest showed a substantial agreement for prediction of ischemic and hemorrhagic events with a Cohen's κ of 0.66 and 0.66, respectively. The P2Y12-receptor specific ADPtest HS assay appears similarly predictive for pharmacodynamic and clinical outcomes as compared to the established ADPtest assay indicating its applicability for clinical use. Further evaluation in large cohorts is needed to determine if P2Y12-receptor specific testing offers any advantage for prediction of clinical outcome.

  9. Effect of Desmopressin on Platelet Aggregation and Blood Loss in Patients Undergoing Valvular Heart Surgery

    Institute of Scientific and Technical Information of China (English)

    Lei Jin; Hong-Wen Ji

    2015-01-01

    Background:Blood loss after cardiac surgery can be caused by impaired platelet (PLT) function after cardiopulmonary bypass.Desmopressin or 1-deamino-8-D-arginine vasopressin (DDAVP) is a synthetic analog of vasopressin.DDAVP can increase the level of von Willebrand factor and coagulation factor Ⅷ,thus it may enhance PLT function and improve coagulation.In this study,we assessed the effects of DDAVP on PLT aggregation and blood loss in patients undergoing cardiac surgery.Methods:A total of 102 patients undergoing valvular heart surgery (from October 2010 to June 2011) were divided into DDAVP group (n =52) and control group (n =50).A dose of DDAVP (0.3 μtg/kg) was administered to the patients intravenously when they were being re-warmed.At the same time,an equal volume of saline was given to the patients in the control group.PLT aggregation rate was measured with the AggRAM four-way PLT aggregation measurement instrument.The blood loss and transfusion,hemoglobin levels,PLT counts,and urine outputs at different time were recorded and compared.Results:The postoperative blood loss in the first 6 h was significantly reduced in DDAVP group (202 ± 119 ml vs.258 ± 143 ml,P =0.023).The incidence of fresh frozen plasma (FFP) transfusion was decreased postoperatively in DDAVP group (3.8% vs.12%,P =0.015).There was no significant difference in the PLT aggregation,urine volumes,red blood cell transfusions and blood loss after 24 h between two groups.Conclusions:A single dose of DDAVP can reduce the first 6 h blood loss and FFP transfusion postoperatively in patients undergoing valvular heart surgery,but has no effect on PLT aggregation.

  10. A whole blood flow cytometric determination of platelet activation by unfractionated and low molecular weight heparin in vitro.

    Science.gov (United States)

    Klein, Bernd; Faridi, Andreé; von Tempelhoff, G F; Heilmann, Lothar; Mittermayer, Christian; Rath, Werner

    2002-12-15

    The influence of unfractionated (Heparin-Natrium) and low-molecular heparin (Fragmin(R)) on platelet activation in whole blood was investigated by FACS analysis in vitro using antibodies against glycoprotein (gp) IIb/IIIa (CD 41), GMP 140 (CD 62P), gp 53 (CD 63) and fibrinogen. Samples were also labeled with anti-gp Ib (CD 42b). Neither unfractionated heparin (UFH) nor low molecular weight heparin (LMWH) led to significant (i.e., p<0.05) changes in fluorescence intensities of platelets labeled with anti-gp IIb/IIIa or anti-gp 53. Significant platelet activation due to unfractionated heparin could be observed by labeling with anti-GMP 140 (UFH: p=0.009; LMWH: p=0.16). The proportion of platelets with surface-bound fibrinogen was significantly increased (UFH: p=0.00006; LMWH: p=0.008). After incubation with heparins, activation ability of platelets by adenosine diphosphate (ADP) was significantly increased. The potentiating action of unfractionated heparin was larger. Therefore, flow cytometric results of platelet activation in patients receiving heparin should be interpreted carefully.

  11. A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study

    Directory of Open Access Journals (Sweden)

    Isha Narang

    2015-01-01

    Full Text Available Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF, platelet-rich plasma (PRP, and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher′s exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2 which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot.

  12. Time-dependent effects of aspirin on blood pressure and morning platelet reactivity: a randomized cross-over trial

    NARCIS (Netherlands)

    Bonten, T.N.; Snoep, J.D.; Assendelft, W.J.; Zwaginga, J.J.; Eikenboom, J.; Huisman, M.V.; Rosendaal, F.R.; Bom, J.G. Van Der

    2015-01-01

    Aspirin is used for cardiovascular disease (CVD) prevention by millions of patients on a daily basis. Previous studies suggested that aspirin intake at bedtime reduces blood pressure compared with intake on awakening. This has never been studied in patients with CVD. Moreover, platelet reactivity an

  13. Seasonal variation of imipramine binding in the blood platelets of normal controls and depressed patients

    Energy Technology Data Exchange (ETDEWEB)

    Arora, R.C.; Meltzer, H.Y.

    1988-02-01

    Imipramine binding (IB) was studied in the blood platelets from normal controls and depressed patients over a 4-year period (1981-1984) to determine if seasonal variation was present in Bmax or KD. Bimonthly variation in the Bmax of IB was found in normal controls studied longitudinally. No such variation was found when individual values from normal controls were examined on a monthly or seasonal basis. Bmax in depressed patients showed a significant seasonal, but not monthly, variation. KD of IB varied in normal controls using monthly or seasonal data, but not in the probably more reliable bimonthly data. These results suggest that IB studies comparing groups of subjects should match groups for season of the year or, for greater accuracy, month of the year.

  14. Alcohol and polyphenolic grape extract inhibit platelet adhesion in flowing blood

    NARCIS (Netherlands)

    de Lange, DW; Scholman, WLG; Kraaijenhagen, RJ; Akkerman, JWN; van de Wiel, A

    2004-01-01

    Background Moderate and prolonged alcohol consumption has been associated with decreased cardiovascular morbidity and mortality. Inhibition of platelet function in suspension attributes to these effects. Whether alcohol, red wine, or polyphenolic grape extracts (PGE) inhibit platelet adhesion is not

  15. Epinephrine enhances platelet-neutrophil adhesion in whole blood in vitro.

    NARCIS (Netherlands)

    Horn, N.A.; Anastase, D.M.; Hecker, K.E.; Baumert, J.H.; Robitzsch, T.; Rossaint, R.

    2005-01-01

    Previous studies showed that alpha- or beta-adrenoceptor stimulation by catecholamines influenced neutrophil function, cytokine liberation, and platelet aggregability. We investigated whether adrenergic stimulation with epinephrine also alters platelet-neutrophil adhesion. This might be of specific

  16. The changes of blood platelet activation in breast cancer patients before surgery, after surgery, and in various phases of the chemotherapy.

    Science.gov (United States)

    Kedzierska, Magdalena; Czernek, Urszula; Szydłowska-Pazera, Katarzyna; Potemski, Piotr; Piekarski, Janusz; Jeziorski, Arkadiusz; Olas, Beata

    2013-01-01

    Blood platelets from patients with cancer (before or after the surgery) exhibit a variety of qualitative abnormalities. Different anti-cancer drugs may also induce the oxidative/nitrative stress in blood platelets and change their hemostatic properties. The aim of our study was to explain the effect of superoxide anion radicals ([Formula: see text]) production on hemostatic properties of blood platelets (activated by a strong physiological agonist - thrombin) from breast cancer patients before the surgery, after the surgery, and after various phases (I-IV) of chemotherapy (doxorubicin and cyclophosphamide). Patients were hospitalized in the Department of Oncological Surgery and at the Department of Chemotherapy, Medical University of Lodz, Poland. We measured the platelet aggregation as the marker of hemostatic activity of blood platelets. We observed an increase of [Formula: see text] in thrombin-activated blood platelets from patients with breast cancer (before or after the surgery and after various phases of the chemotherapy) compared to the healthy group. Our other experiments demonstrated that aggregation (induced by thrombin) of blood platelets from patients with breast cancer before the surgery, after the surgery, and after various phases of the chemotherapy differs from aggregation of platelets obtained from healthy volunteers. Moreover, our results showed the correlation between the [Formula: see text] generation and changes of platelet aggregation in breast cancer patients before the surgery, after the surgery, and after the chemotherapy (I and IV phases). Considering the data presented in this study, we suggest that the production of [Formula: see text] in blood platelets (activated by thrombin) obtained from breast cancer patients may induce the changes of platelet aggregation, which may contribute in thrombosis in these patients.

  17. The ultrastructure of camel blood platelets: a comparative study with human, bovine, and equine cells.

    Science.gov (United States)

    Gader, Abdel Galil M Abdel; Ghumlas, Abeer K Al; Hussain, Mansour F; Haidari, Ahmed Al; White, James G

    2008-02-01

    Previous studies indicated that the camel has a very active haemostatic mechanism with a short bleeding time and thrombocytosis. However, platelet function, when tested by agonist-induced aggregation and PFA 100 closure time, showed marked inhibition compared to humans. Since camels are also far more resistant to long exposure to excessive heat and high body temperature than humans, it seemed worthwhile to explore fundamental morphological differences between human and camel platelets and those from other species. The present study has examined the ultrastructure of camel platelets and compared them with the fine structures of human, bovine and equine thrombocytes. Camel platelets, like bovine and equine cells, are discoid in shape and about two-thirds the size of human platelets. A circumferential coil of microtubular supports the disk-like form of camel platelets. Their cytoplasm, like bovine and equine platelets, is filled with alpha granule twice as large as those in human platelets, but lacking the organized matrix of equine alpha granules. Dense bodies are present in camel platelets with whip-like extensions not present on bovine or equine thrombocytes, but found on occasional human platelet dense bodies. Camel platelets, like bovine and equine thrombocytes, lack an open canalicular system (OCS) and must secrete granule products by fusion with the cell wall rather than an OCS. Future studies will determine if the differences in ultrastructural anatomy protect camel platelets from heat more than human thrombocytes.

  18. Assessment of the influence of the inflammatory process on the activation of blood platelets and morphological parameters in patients with ulcerative colitis (colitis ulcerosa

    Directory of Open Access Journals (Sweden)

    Beata Polińska

    2011-04-01

    Full Text Available Ulcerative colitis (colitis ulcerosa is a non-specific inflammatory bowel disease of unknown etiology. Thesymptoms which are observed in the course of ulcerative colitis are: an increase in the number of leukocytes andblood platelets, an increase in the concentration of IL-6 and anemia. Blood platelets are the key element, linkingthe processes of hemostasis, inflammation and the repair of damaged tissues. Activation of blood platelets is connectedwith changes in their shape and the occurrence of the reaction of release. P-selectin appears on the surfacesof activated blood platelets and the concentration level of soluble P-selectin increases in the blood plasma. The aimof this study was to define whether the increased number of blood platelets in patients with ulcerative colitisaccompanies changes in their activation and morphology. A total of 16 subjects with ulcerative colitis and 32healthy subjects were studied. Mean platelet count, morphological parameters of platelets and MPC were measuredusing an ADVIA 120 hematology analyzer. Concentrations of sP-selectin and IL-6 in serum were marked byimmunoassay (ELISA. MPC, concentration of sP-selectin and IL-6 were significantly higher in subjects with ulcerativecolitis compared to those in the healthy group. There was a decrease of MPV in patients with ulcerativecolitis, which is statistically significant. Chronic inflammation in patients with ulcerative colitis causes an increase inthe number of blood platelets, a change in their morphology and activation. Decreased MPV value reflects activationand the role blood platelets play in the inflammatory process of the mucous membrane of the colon. A highconcentration of sP-selectin, which is a marker of blood platelet activation, demonstrates their part in the inflammatoryprocess. The increase in the concentration of sP-selectin correlated positively with the increase in concentrationof IL-6. This is why it may be a useful marker of the activity of

  19. The effect of occupational exposure to formaldehyde on blood platelets of employees in a wood industry company

    Directory of Open Access Journals (Sweden)

    2013-02-01

    Full Text Available Introduction: Existing literatures indicate that occupational exposure to formaldehyde may decrease blood platelets. In this study, the influences of occupational exposure to formaldehyde on the number of blood plateletsand clinical symptoms were studied while determining the occupational exposure of employees of a wood industry to formaldehyde. .Material and Method: In a case study, the occupational exposure to formaldehyde was determined among 30 workers from production line and 30 administrative staffs of a wood company using US-NIOSH method No 2541. The number of blood platelets was determined using the normal blood count method and related indices. Demographic data as well as the clinical symptoms of exposure to formaldehyde were collected using a standard questionnaire. The smokers and those using drugs interacting with similar symptoms and blood characteristics were excluded from the study. Ethical principles for medical research involving human subjects announced in Helsinki declaration were considered. The research proposal had been approved by the university committee of ethics prior to its execution. Details of tests were explained for all subjects and a written consent was signed by each subject. .Result: Occupational exposure of workers in various parts of particle board production line ranged from 0.5 ppm to 1.52 ppm which was higher than the ceiling level (0.3 ppm recommended by US-ACGIH. The prevalence of all studied symptoms from formaldehyde exposure in workers was significantly higher than the administrative staffs. In case group, tearing rate was the highest average 8.98 while the chest pain with an average rate of 3.20 was the lowest. In control group, the prevalence of coughing with an average rate of 6.62 was the highest and the chest pain with an average rate of 5.53 was the lowest. The average number and standard deviation of blood platelets of workers in production line and staffs were statistically different with the

  20. [Automated measurement of reticulocyte count by flow cytometry. II: Analysis of the blood containing abnormal erythrocytes or giant platelets].

    Science.gov (United States)

    Oyamatsu, T; Shimizu, N; Takeuchi, K; Yamamoto, M; Kawai, Y; Watanabe, K; Iri, H

    1989-07-01

    We have examined the influence of erythrocytes containing inclusion bodies, nucleated red cells or giant platelets on the measurement of reticulocyte count by automated machine, R-1000. Correlation of the reticulocyte count between automated and conventional method was extremely good in the blood containing red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling . However, correlation was poor when the sample contained the nucleated red cells. Reticulocyte count was decreased in the blood with significant amounts of nucleated red cells. Since nucleated red cells themselves are not counted as reticulocytes in the machine, this was considered to be due to increased young reticulocytes which frequently appeared with nucleated red cells. Both cold agglutinated red cells and giant platelets apparently influenced the reticulocyte count by the R-1000. These results suggest that red cells with Jolly bodies, Pappenheimer bodies or basophilic stippling do not influence the automatic counting of reticulocytes. Although nucleated red cells, cold agglutinated red cells and giant platelets affected the reticulocyte count, the machine shows abnormal flags in most of above cases (except highly agglutinated red cells), so that one can recount reticulocytes by conventional method. We conclude the machine can safely count the reticulocytes even in the blood containing abnormal red cells or platelets.

  1. Evaluation of polyphenolic fraction isolated from aerial parts of Tribulus pterocarpus on biological properties of blood platelets in vitro.

    Science.gov (United States)

    Olas, Beata; Morel, Agnieszka; Hamed, Arafa I; Oleszek, Wieslaw; Stochmal, Anna

    2013-01-01

    The antiplatelet and antioxidative activity of polyphenolic fraction isolated from aerial parts of Tribulus pterocarpus in blood platelets stimulated by thrombin was studied. Thrombin as a strong physiological agonist induces the enzymatic peroxidation of endogenous arachidonic acid, the formation of different reactive oxygen species, including superoxide anion radicals ([Formula: see text](·)) and the platelet aggregation. Therefore, the aim of our study was to assess if the polyphenolic fraction from aerial parts of T. pterocarpus may change the biological properties of blood platelets activated by thrombin. We used cytochrome c reduction method to test the ability of this fraction to change [Formula: see text](·) generation in platelets. Arachidonic acid metabolism was measured by the level of thiobarbituric acid reactive substances (TBARS) and by the production of 8-epi-prostaglandin (8-EPI) F(2). Moreover, we determined the effects of the fraction on blood platelet aggregation induced by thrombin. We observed that the polyphenolic fraction from T. pterocarpus reduced [Formula: see text](·), 8-EPI and TBARS production in these cells. The ability of the fraction to decrease the [Formula: see text](·) generation in blood platelets supports the importance of free radicals in platelet functions, including aggregation process. This study may suggest that the tested plant fraction might be a good candidate for protecting blood platelets against changes of their biological functions, which may be associated with the pathogenesis of different cardiovascular disorders.

  2. Venous levels of shear support neutrophil-platelet adhesion and neutrophil aggregation in blood via P-selectin and beta2-integrin

    Science.gov (United States)

    Konstantopoulos, K.; Neelamegham, S.; Burns, A. R.; Hentzen, E.; Kansas, G. S.; Snapp, K. R.; Berg, E. L.; Hellums, J. D.; Smith, C. W.; McIntire, L. V.; Simon, S. I.

    1998-01-01

    BACKGROUND: After activation, platelets adhere to neutrophils via P-selectin and beta2-integrin. The molecular mechanisms and adhesion events in whole blood exposed to venous levels of hydrodynamic shear in the absence of exogenous activation remain unknown. METHODS AND RESULTS: Whole blood was sheared at approximately 100 s(-1). The kinetics of neutrophil-platelet adhesion and neutrophil aggregation were measured in real time by flow cytometry. P-selectin was upregulated to the platelet surface in response to shear and was the primary factor mediating neutrophil-platelet adhesion. The extent of neutrophil aggregation increased linearly with platelet adhesion to neutrophils. Blocking either P-selectin, its glycoprotein ligand PSGL-1, or both simultaneously by preincubation with a monoclonal antibody resulted in equivalent inhibition of neutrophil-platelet adhesion (approximately 30%) and neutrophil aggregation (approximately 70%). The residual amount of neutrophil adhesion was blocked with anti-CD11b/CD18. Treatment of blood with prostacyclin analogue ZK36374, which raises cAMP levels in platelets, blocked P-selectin upregulation and neutrophil aggregation to baseline. Complete abrogation of platelet-neutrophil adhesion required both ZK36374 and anti-CD18. Electron microscopic observations of fixed blood specimens revealed that platelets augmented neutrophil aggregation both by forming bridges between neutrophils and through contact-mediated activation. CONCLUSIONS: The results are consistent with a model in which venous levels of shear support platelet adherence to neutrophils via P-selectin binding PSGL-1. This interaction alone is sufficient to mediate neutrophil aggregation. Abrogation of platelet adhesion and aggregation requires blocking Mac-1 in addition to PSGL-1 or P-selectin. The described mechanisms are likely of key importance in the pathogenesis and progression of thrombotic disorders that are exacerbated by leukocyte-platelet aggregation.

  3. Incidence of thrombocytopenia and changes in various platelet parameters, in blood culture positive neonatal sepsis

    Directory of Open Access Journals (Sweden)

    Sartaj Bhat

    2015-07-01

    Full Text Available Abstract Objective: To assess the incidence of thrombocytopenia and changes in various platelet parameters, in culture positive neonatal sepsis. Methods: This was prospective study conducted over a period of one year from December 2009 to November 2010 in neonatal intensive care unit of DDUH Hospital, a tertiary care hospital in Delhi, North India. All babies who were admitted during this period were evaluated prospectively for evidence of sepsis. Results: sepsis was diagnosed in 560 neonates. Among 560 neonates, 80/560 (14.28% had Culture positive sepsis. Out of 80 blood culture positive neonates 73 were term neonates and 7 were near term. Gram positive sepsis occurred in 21/80 (26.25%, gram negative sepsis in 54/80 (67.5%, and fungal sepsis in 5/80 (6.25%. Incidence of thrombocytopenia in Gram negative sepsis was (35/54 64.81%, in gram positive sepsis (15/21 71.41% and in fungal sepsis was (3/5 60%. Mean platelet count at the onset of sepsis in all the patients was 123287.5±49428.68. The mean duration of thrombocytopenia in gram positive sepsis was 4.66 ±2.6 days, in gram negative sepsis 4.39 ± 2.22 days and in fungal sepsis 5.2±1.3 days. MPV at the time of onset of sepsis (MPV was high in gram positive sepsis than in gram negative sepsis (11.57±0.88 Vs 11.29 ± 0.76. The MPV of thrombocytopenic neonates was significantly higher than that of non-thrombocytopenic neonates (p < 0.01.

  4. Increased platelet oxidative metabolism, blood oxidative stress and neopterin levels after ultra-endurance exercise.

    Science.gov (United States)

    de Lucas, Ricardo Dantas; Caputo, Fabrizio; Mendes de Souza, Kristopher; Sigwalt, André Roberto; Ghisoni, Karina; Lock Silveira, Paulo Cesar; Remor, Aline Pertile; da Luz Scheffer, Débora; Guglielmo, Luiz Guilherme Antonacci; Latini, Alexandra

    2014-01-01

    The purpose of the present investigation was to identify muscle damage, inflammatory response and oxidative stress blood markers in athletes undertaking the ultra-endurance MultiSport Brazil race. Eleven well-trained male athletes (34.3 ± 3.1 years, 74.0 ± 7.6 kg; 172.2 ± 5.1 cm) participated in the study and performed the race, which consisted of about 90 km of alternating off-road running, mountain biking and kayaking. Twelve hours before and up to 15 minutes after the race a 10 mL blood sample was drawn in order to measure the following parameters: lactate dehydrogenase and creatine kinase activities, lipid peroxidation, catalase activity, protein carbonylation, respiratory chain complexes I, II and IV activities, oxygen consumption and neopterin concentrations. After the race, plasma lactate dehydrogenase and creatine kinase activities were significantly increased. Erythrocyte TBA-RS levels and plasma protein carbonylation were markedly augmented in post-race samples. Additionally, mitochondrial complex II activity and oxygen consumption in post-race platelet-rich plasma were also increased. These altered biochemical parameters were accompanied by increased plasma neopterin levels. The ultra-endurance event provoked systemic inflammation (increased neopterin) accompanied by marked oxidative stress, likely by increasing oxidative metabolism (increased oxidative mitochondrial function). This might be advantageous during prolonged exercise, mainly for efficient substrate oxidation at the mitochondrial level, even when tissue damage is induced.

  5. Modeling HIV-1 Induced Neuroinflammation in Mice: Role of Platelets in Mediating Blood-Brain Barrier Dysfunction.

    Science.gov (United States)

    Jones, Letitia D; Jackson, Joseph W; Maggirwar, Sanjay B

    2016-01-01

    The number of HIV-1 positive individuals developing some form of HIV-associated neurocognitive disorder (HAND) is increasing. In these individuals, the integrity of the blood-brain barrier (BBB) is compromised due to an increase in exposure to pro-inflammatory mediators, viral proteins, and virus released from infected cells. It has been shown that soluble CD40L (sCD40L) is released upon platelet activation and is an important mediator of the pathogenesis of HAND but the underlying mechanisms are unclear, emphasizing the need of an effective animal model. Here, we have utilized a novel animal model in which wild-type (WT) mice were infected with EcoHIV; a derivative of HIV-1 that contains a substitution of envelope protein gp120 with that of gp80 derived from murine leukemia virus-1 (MuLV-1). As early as two-weeks post-infection, EcoHIV led to increased permeability of the BBB associated with decreased expression of tight junction protein claudin-5, in CD40L and platelet activation-dependent manner. Treatment with an antiplatelet drug, eptifibatide, in EcoHIV-infected mice normalized BBB function, sCD40L release and platelet activity, thus implicating platelet activation and platelet-derived CD40L in virally induced BBB dysfunction. Our results also validate and underscore the importance of EcoHIV infection mouse model as a tool to explore therapeutic targets for HAND.

  6. Modeling HIV-1 Induced Neuroinflammation in Mice: Role of Platelets in Mediating Blood-Brain Barrier Dysfunction.

    Directory of Open Access Journals (Sweden)

    Letitia D Jones

    Full Text Available The number of HIV-1 positive individuals developing some form of HIV-associated neurocognitive disorder (HAND is increasing. In these individuals, the integrity of the blood-brain barrier (BBB is compromised due to an increase in exposure to pro-inflammatory mediators, viral proteins, and virus released from infected cells. It has been shown that soluble CD40L (sCD40L is released upon platelet activation and is an important mediator of the pathogenesis of HAND but the underlying mechanisms are unclear, emphasizing the need of an effective animal model. Here, we have utilized a novel animal model in which wild-type (WT mice were infected with EcoHIV; a derivative of HIV-1 that contains a substitution of envelope protein gp120 with that of gp80 derived from murine leukemia virus-1 (MuLV-1. As early as two-weeks post-infection, EcoHIV led to increased permeability of the BBB associated with decreased expression of tight junction protein claudin-5, in CD40L and platelet activation-dependent manner. Treatment with an antiplatelet drug, eptifibatide, in EcoHIV-infected mice normalized BBB function, sCD40L release and platelet activity, thus implicating platelet activation and platelet-derived CD40L in virally induced BBB dysfunction. Our results also validate and underscore the importance of EcoHIV infection mouse model as a tool to explore therapeutic targets for HAND.

  7. Platelet proteomics.

    Science.gov (United States)

    Zufferey, Anne; Fontana, Pierre; Reny, Jean-Luc; Nolli, Severine; Sanchez, Jean-Charles

    2012-01-01

    Platelets are small cell fragments, produced by megakaryocytes, in the bone marrow. They play an important role in hemostasis and diverse thrombotic disorders. They are therefore primary targets of antithrombotic therapies. They are implicated in several pathophysiological pathways, such as inflammation or wound repair. In blood circulation, platelets are activated by several pathways including subendothelial matrix and thrombin, triggering the formation of the platelet plug. Studying their proteome is a powerful approach to understand their biology and function. However, particular attention must be paid to different experimental parameters, such as platelet quality and purity. Several technologies are involved during the platelet proteome processing, yielding information on protein identification, characterization, localization, and quantification. Recent technical improvements in proteomics combined with inter-disciplinary strategies, such as metabolomic, transcriptomics, and bioinformatics, will help to understand platelets biological mechanisms. Therefore, a comprehensive analysis of the platelet proteome under different environmental conditions may contribute to elucidate complex processes relevant to platelet function regarding bleeding disorders or platelet hyperreactivity and identify new targets for antiplatelet therapy.

  8. How do the full-generation poly(amido)amine (PAMAM) dendrimers activate blood platelets? Activation of circulating platelets and formation of "fibrinogen aggregates" in the presence of polycations.

    Science.gov (United States)

    Watala, Cezary; Karolczak, Kamil; Kassassir, Hassan; Talar, Marcin; Przygodzki, Tomasz; Maczynska, Katarzyna; Labieniec-Watala, Magdalena

    2016-04-30

    Direct use of poly(amido)amine (PAMAM) dendrimers as drugs may be limited, due to uncertain (cyto)toxicity. Peripheral blood components, which constitute the first line of a contact with administered pharmaceuticals, may become vastly affected by PAMAM dendrimers. The aim of this study was to explore how PAMAMs' polycationicity might affect blood platelet activation and reactivity, and thus trigger various haemostatic events. We monitored blood platelet reactivity in rats with experimental diabetes upon a long-term administration of the unmodified PAMAM dendrimers. In parallel, the effects on blood flow in a systemic circulation was recorded intravitally in mice administered with PAMAM G2, G3 or G4. Compounding was the in vitro approach to monitor the impact of PAMAM dendrimers on blood platelet activation and reactivity and on selected haemostatic and protein conformation parameters. We demonstrated the activating effects of polycations on blood platelets. Some diversity of the revealed outcomes considerably depended on the used approach and the particular technique employed to monitor blood platelet function. We discovered undesirable impact of plain PAMAM dendrimers on primary haemostasis and their prothrombotic influence. We emphasize the need of a more profound verifying of all the promising findings collected for PAMAMs with the use of well-designed in vivo preclinical studies.

  9. Genetically engineered blood pharming: generation of HLA-universal platelets derived from CD34+ progenitor cells.

    Science.gov (United States)

    Figueiredo, Constança; Blaszczyk, Rainer

    2014-01-01

    Blood pharming is a recently designed concept to enable in vitro production of blood cells that are safe, effective and readily available. This approach represents an alternative to blood donation and may contribute to overcome the shortage of blood products. However, the high variability of the human leukocyte antigen (HLA) loci remains a major hurdle to the application of off-the-shelf blood products. Refractoriness to platelet (PLT) transfusion caused by alloimmunization against HLA class I antigens constitutes a relevant clinical problem. Thus, it would be desirable to generate PLT units devoid of HLA antigens. To reduce the immunogenicity of cell-based therapeutics, we have permanently reduced HLA class I expression using an RNA interference strategy. Furthermore, we demonstrated that the generation of HLA class I-silenced (HLA-universal) PLTs from CD34+ progenitor cells using an shRNA targeting β2-microglobulin transcripts is feasible. CD34+ progenitor cells derived from G-CSF mobilised donors were transduced with a lentiviral vector encoding for the β2-microglobulin-specific shRNA and differentiated into PLTs using a liquid culture system. The functionality of HLA-silenced PLTs and their ability to escape HLA antibody-mediated cytotoxicity were evaluated in vitro and in vivo. Platelet activation in response to ADP and thrombin were assessed in vitro. The immune-evasion capability of HLA-universal megakaryocytes (MKs) and PLTs was tested in lymphocytotoxicity assays using anti-HLA antibodies. To assess the functionality of HLA-universal PLTs in vivo, HLA-silenced MKs were infused into NOD/SCID/IL-2Rγc(-/-) mice with or without anti-HLA antibodies. PLT generation was evaluated by flow cytometry using anti-CD42a and CD61 antibodies. HLA-universal PLTs demonstrated to be functionally similar to blood-derived PLTs. Lymphocytotoxicity assays showed that HLA-silencing efficiently protects MKs against HLA antibody-mediated complement-dependent cytotoxicity. 80

  10. Blood coagulation parameters and platelet indices: changes in normal and preeclamptic pregnancies and predictive values for preeclampsia.

    Directory of Open Access Journals (Sweden)

    Lei Han

    Full Text Available Preeclampsia (PE is an obstetric disorder with high morbidity and mortality rates but without clear pathogeny. The dysfunction of the blood coagulation-fibrinolysis system is a salient characteristic of PE that varies in severity, and necessitates different treatments. Therefore, it is necessary to find suitable predictors for the onset and severity of PE.We aimed to evaluate blood coagulation parameters and platelet indices as potential predictors for the onset and severity of PE.Blood samples from 3 groups of subjects, normal pregnant women (n = 79, mild preeclampsia (mPE (n = 53 and severe preeclampsia (sPE (n = 42, were collected during early and late pregnancy. The levels of coagulative parameters and platelet indices were measured and compared among the groups. The receiver-operating characteristic (ROC curves of these indices were generated, and the area under the curve (AUC was calculated. The predictive values of the selected potential parameters were examined in binary regression analysis.During late pregnancy in the normal pregnancy group, the activated partial thromboplastin time (APTT, prothrombin time (PT, thrombin time (TT and platelet count decreased, while the fibrinogen level and mean platelet volume (MPV increased compared to early pregnancy (p<0.05. However, the PE patients presented with increased APTT, TT, MPV and D-dimer (DD during the third trimester. In the analysis of subjects with and without PE, TT showed the largest AUC (0.743 and high predictive value. In PE patients with different severities, MPV showed the largest AUC (0.671 and ideal predictive efficiency.Normal pregnancy causes a maternal physiological hypercoagulable state in late pregnancy. PE may trigger complex disorders in the endogenous coagulative pathways and consume platelets and FIB, subsequently activating thrombopoiesis and fibrinolysis. Thrombin time and MPV may serve as early monitoring markers for the onset and severity of PE

  11. Protective action of proanthocyanidin fraction from Medemia argun nuts against oxidative/nitrative damages of blood platelet and plasma components.

    Science.gov (United States)

    Morel, Agnieszka; Hamed, Arafa I; Oleszek, Wieslaw; Stochmal, Anna; Głowacki, Rafał; Olas, Beata

    2014-01-01

    The oxidative/nitrative stress induced by different factors plays an important role in the pathogenesis of various disorders, including cardiovascular diseases and cancer. Proanthocyanidins have antioxidative properties and may protect biomolecules (lipids, DNA, and proteins) exposed to reactive oxygen and nitrogen species, including peroxynitrite (ONOO(-)). The effects of proanthocyanidin fraction from Medemia argun nuts on oxidative/nitrative protein damages (determined by such parameters as level of thiol groups, carbonyl groups, and nitrotyrosine residues) and on the amount of glutathione (as an important component of redox status; using HPLC) in human blood platelets and plasma after treatment with peroxynitrite were studied in vitro. The preincubation of blood platelets and plasma with proanthocyanidin fraction from M. argun nuts (0.5-50 µg/ml) reduced the formation of 3-nitrotyrosine, diminished oxidation of thiol groups, and decreased the level of carbonyl groups in proteins caused by 100 µM peroxynitrite. An action of tested plant fraction and ONOO(-) evoked a significant increase of GSH in platelets and plasma in comparison with platelets and plasma treated with ONOO(-) only. The proanthocyanidin fraction from M. argun nuts can be useful as a protecting factor against oxidative/nitrative stress associated with different diseases (cancer, cardiovascular, and neurodegenerative diseases) and proanthocyanidins of M. argun nuts may be promising antioxidants.

  12. Blood Types

    Science.gov (United States)

    ... maternity. Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells Platelets Plasma ... About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity ...

  13. [Morphology, ultrastructure and function of glycosylation-modified chilled blood platelets].

    Science.gov (United States)

    Guo, Yong; Han, Ying; Quan, Guo-Bo; Liu, Min-Xia; Liu, An

    2008-04-01

    The glycosylation of platelets may prolong their life-span when being transfused after preservation under 4 degrees C, therefore this study was aimed to investigate the effect of glycosylation on morphology, ultrastructure, function and membrane glycoprotein of platelets. The experiments were divided into 3 groups: group preserved in room temperature (RT group), group preserved in 4 degrees C (4T group) and group UDP-Gal glycosylated and preserved in 4 degrees C (U+4T group). The binding rate of RCA I lectin and expression of platelet surface markers CD62P, CD42b were determined by flow cytometry. Morphology and ultrastructure of platelets were observed by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Platelets aggregation was detected by aggregometer. The results showed that the binding rate of RCAI in U+4T group significantly higher than that in RT group (pplatelets, as compared with fresh platelets. Some morphologic changes, such as pseudopodium could be observed in 4T group. The aggregation rate of platelets in U+4T group reached to 50% of RT group. The expression levels of CD42b and CD62P, and the binding rate of annexin V in U+4T group were not significantly different from that in RT group. It is concluded that UDP-Gal can effectively cause galactosylation of platelets, and the platelets modified with UDP-Gal remain normal morphology, ultrastructure and function.

  14. Relationship between the Increased Haemostatic Properties of Blood Platelets and Oxidative Stress Level in Multiple Sclerosis Patients with the Secondary Progressive Stage

    Directory of Open Access Journals (Sweden)

    Agnieszka Morel

    2015-01-01

    Full Text Available Multiple sclerosis (MS is the autoimmune disease of the central nervous system with complex pathogenesis, different clinical courses and recurrent neurological relapses and/or progression. Despite various scientific papers that focused on early stage of MS, our study targets selective group of late stage secondary progressive MS patients. The presented work is concerned with the reactivity of blood platelets in primary hemostasis in SP MS patients. 50 SP MS patients and 50 healthy volunteers (never diagnosed with MS or other chronic diseases were examined to evaluate the biological activity of blood platelets (adhesion, aggregation, especially their response to the most important physiological agonists (thrombin, ADP, and collagen and the effect of oxidative stress on platelet activity. We found that the blood platelets from SP MS patients were significantly more sensitive to all used agonists in comparison with control group. Moreover, the platelet hemostatic function was advanced in patients suffering from SP MS and positively correlated with increased production of O2-∙ in these cells, as well as with Expanded Disability Status Scale. We postulate that the increased oxidative stress in blood platelets in SP MS may be primarily responsible for the altered haemostatic properties of blood platelets.

  15. Effects of red blood cell deformability on the non-uniform distribution of platelet-sized particles in blood flow through microchannels

    Science.gov (United States)

    Sugihara-Seki, Masako; Sakamoto, Keisuke; Itano, Tomoaki; Seki, Junji

    2016-11-01

    In blood flow through microvessels, platelets are known to have enhanced concentrations near the vessel wall, which is the so-called "near-wall excess (NWE)". This phenomenon is considered to be caused by the interaction with red blood cells (RBCs); since RBCs have a tendency to approach the vessel centerline due to their highly deformability, they may push away less deformable platelets toward the near-wall region. In order to examine this proposition by in vitro experiments, we measured the distribution of platelet-sized particles mixed in intact RBC or hardened RBC suspensions flowing through microchannels of 50 μm x 50 μm cross-section. Hardened RBCs were prepared by immersing human RBCs in glutaraldehayde solution of 40 - 4000 ppm. Fluorescent observations were conducted with the use of a confocal laser scanning microscope system with a high-speed video camera. It was found that platelet-sized particles exhibited high concentrations near the channel wall, i.e., NWE, when they were mixed in intact RBC suspensions. By contrast, the particles mixed in hardened RBC suspensions showed weak NWE or uniform distribution over the channel cross-section, indicating that deformability of RBCs plays an essential role in the NWE phenomenon.

  16. Whole blood coagulation and platelet activation in the athlete: A comparison of marathon, triathlon and long distance cycling

    Directory of Open Access Journals (Sweden)

    Hanke AA

    2010-02-01

    Full Text Available Abstract Introduction Serious thrombembolic events occur in otherwise healthy marathon athletes during competition. We tested the hypothesis that during heavy endurance sports coagulation and platelets are activated depending on the type of endurance sport with respect to its running fraction. Materials and Methods 68 healthy athletes participating in marathon (MAR, running 42 km, n = 24, triathlon (TRI, swimming 2.5 km + cycling 90 km + running 21 km, n = 22, and long distance cycling (CYC, 151 km, n = 22 were included in the study. Blood samples were taken before and immediately after completion of competition to perform rotational thrombelastometry. We assessed coagulation time (CT, maximum clot firmness (MCF after intrinsically activation and fibrin polymerization (FIBTEM. Furthermore, platelet aggregation was tested after activation with ADP and thrombin activating peptide 6 (TRAP by using multiple platelet function analyzer. Results Complete data sets were obtained in 58 athletes (MAR: n = 20, TRI: n = 19, CYC: n = 19. CT significantly decreased in all groups (MAR -9.9%, TRI -8.3%, CYC -7.4% without differences between groups. In parallel, MCF (MAR +7.4%, TRI +6.1%, CYC +8.3% and fibrin polymerization (MAR +14.7%, TRI +6.1%, CYC +8.3% were significantly increased in all groups. However, platelets were only activated during MAR and TRI as indicated by increased AUC during TRAP-activation (MAR +15.8% and increased AUC during ADP-activation in MAR (+50.3% and TRI (+57.5%. Discussion While coagulation is activated during physical activity irrespective of type we observed significant platelet activation only during marathon and to a lesser extent during triathlon. We speculate that prolonged running may increase platelet activity, possibly, due to mechanical alteration. Thus, particularly prolonged running may increase the risk of thrombembolic incidents in running athletes.

  17. The miRNA Profile of Platelets Stored in a Blood Bank and Its Relation to Cellular Damage from Storage.

    Science.gov (United States)

    Pontes, Thaís Brilhante; Moreira-Nunes, Caroline de Fátima Aquino; Maués, Jersey Heitor da Silva; Lamarão, Letícia Martins; de Lemos, José Alexandre Rodrigues; Montenegro, Raquel Carvalho; Burbano, Rommel Mário Rodriguez

    2015-01-01

    Millions of blood products are transfused each year, and many lives are directly affected by transfusion. Platelet concentrate (PC) is one of the main products derived from blood. Even under good storage conditions, PC is likely to suffer cell damage. The shape of platelets changes after 5 to 7 days of storage at 22°C. Taking into consideration that some platelet proteins undergo changes in their shape and functionality during PC storage. Sixteen PC bags were collected and each PC bag tube was cut into six equal pieces to perform experiments with platelets from six different days of storage. Thus, on the first day of storage, 1/6 of the tube was used for miRNA extraction, and the remaining 5/6 was stored under the same conditions until extraction of miRNAs on each the following five days. Samples were sequenced on an Illumina Platform to demonstrate the most highly expressed miRNAs. Three miRNAs, mir127, mir191 and mir320a were validated by real-time quantitative PCR (RQ-PCR) in 100 PC bags tubes. Our method suggests, the use of the miRNAs mir127 and mir320a as biomarkers to assess the "validity period" of PC bags stored in blood banks for long periods. Thus, bags can be tested on the 5th day of storage for the relative expression levels of mir127 and mir320a. Thus, we highlight candidate miRNAs as biomarkers of storage damage that can be used as tools to evaluate the quality of stored PC. The use of miRNAs as biomarkers of damage is unprecedented and will contribute to improved quality of blood products for transfusions.

  18. Hydroxyl-platelet-activating factor exists in blood of healthy volunteers and periodontal patients

    Directory of Open Access Journals (Sweden)

    Smaragdi Antonopoulou

    2003-01-01

    Full Text Available Periodontal diseases are localized chronic inflammatory conditions of the gingival and underlying bone and connective tissue. Platelet-activating factor (PAF, a potent inflammatory phospholipid mediator that has been previously detected in elevated levels in inflamed gingival tissues, in gingival crevicular fluid and in saliva, is implicated in periodontal disease. Our results from previous studies showed that the biologically active phospholipid detected in gingival crevicular fluid is a hydroxyl-PAF analogue. In this study, hydroxyl-PAF analogue was detected for the first time in human blood derived from patients with chronic periodontitis as well as from periodontally healthy volunteers. The hydroxyl-PAF analogue was purified by high-performance liquid chromatography, detected by biological assays and identified by electrospray analysis. In addition, the quantitative determination of PAF and hydroxyl-PAF analogue (expressed as PAF-like activity showed a statistically significant increase in the ratio of hydroxyl-PAF analogue levels to PAF levels in periodontal patients, suggesting that this bioactive lipid may play a role in oral inflammation.

  19. Human Platelet Antigen Alleles in 998 Taiwanese Blood Donors Determined by Sequence-Specific Primer Polymerase Chain Reaction

    Directory of Open Access Journals (Sweden)

    Shun-Chung Pai

    2013-01-01

    Full Text Available Polymorphism of human platelet antigens (HPAs leads to alloimmunizations and immune-mediated platelet disorders including fetal-neonatal alloimmune thrombocytopenia (FNAIT, posttransfusion purpura (PTP, and platelet transfusion refractoriness (PTR. HPA typing and knowledge of antigen frequency in a population are important in particular for the provision of HPA-matched blood components for patients with PTR. We have performed allele genotyping for HPA-1 through -6 and -15 among 998 platelet donors from 6 blood centers in Taiwan using sequence-specific primer polymerase chain reaction. The HPA allele frequency was 99.55, and 0.45% for HPA-1a and -1b; 96.49, and 3.51% for HPA-2a and -2b; 55.81, and 44.19% for HPA-3a and -3b; 99.75, and 0.25% for HPA-4a and -4b; 98.50, and 1.50% for HPA-5a and -5b; 97.75 and 2.25% for HPA-6a and -6b; 53.71 and 46.29% for HPA-15a and -15b. HPA-15b and HPA-3a, may be considered the most important, followed by HPA-2, -6, -1, -5, and -4 systems, as a cause of FNAIT, PTP, and PTR based on allele frequency. HPA-4b and HPA-5b role cannot be excluded based on their immunogenicity. A larger-scale study will now be conducted to confirm these hypotheses and to establish an apheresis donor database for the procurement of HPA-matched apheresis platelets for patients with PTR.

  20. Dopamine concentration in blood platelets is elevated in patients with head and neck paragangliomas

    NARCIS (Netherlands)

    Osinga, Thamara E.; van der Horst-Schrivers, Anouk N A; van Faassen, Martijn; Kerstens, Michiel N; Dullaart, Robin P F; Peters, Marloes A M; van der Laan, Bernard F A M; de Bock, Geertruida H; Links, Thera P; Kema, Ido P

    2015-01-01

    BACKGROUND: Plasma 3-methoxytyramine (3-MT), a metabolite of dopamine, is elevated in up to 28% of patients with head and neck paragangliomas (HNPGLs). As free dopamine is incorporated in circulating platelets, we determined dopamine concentration in platelets in patients with a HNPGL. METHODS: A si

  1. The effect of ticlopidine administration to humans on the binding of adenosine diphosphate to blood platelets

    NARCIS (Netherlands)

    Lips, J.P.M.; Sixma, J.J.; Schiphorst, M.E.

    1980-01-01

    Administration of Ticlopidine to human volunteers resulted in a prolonged bleeding time and decreased or absent aggregation of platelets with collagen and epinephrine. Adenosine diphosphate (ADP) induced platelet aggregation was initiated by a normal shape change, but the rate of the first wave of a

  2. Clovamide-rich extract from Trifolium pallidum reduces oxidative stress-induced damage to blood platelets and plasma.

    Science.gov (United States)

    Kolodziejczyk, Joanna; Olas, Beata; Wachowicz, Barbara; Szajwaj, Barbara; Stochmal, Anna; Oleszek, Wieslaw

    2011-09-01

    Numerous plants (including clovers) have been widely used in folk medicine for the treatment of different disorders. This in vitro study was designed to examine the antioxidative effects of the clovamide-rich fraction, obtained from aerial parts of Trifolium pallidum, in the protection of blood platelets and plasma against the nitrative and oxidative damage, caused by peroxynitrite (ONOO(-)). Carbonyl groups and 3-nitrotyrosine in blood platelet and plasma proteins were determined by ELISA tests. Thiol groups level was estimated by using 5,5'-dithio-bis(2-nitro-benzoic acid, DTNB). Plasma lipid peroxidation was measured spectrophotometrically as the production of thiobarbituric acid reactive substances. The results from our work indicate that clovamide-rich T. pallidum extract may reveal the protective properties in the prevention against oxidative stress. The presence of clovamide-rich T. pallidum extract (12.5-100 μg/ml) partly inhibited ONOO(-)-mediated protein carbonylation and nitration. All the used concentrations of T. pallidum extract reduced lipid peroxidation in plasma. The antioxidative action of the tested extract in the protection of blood platelet lipids was less effective; the extract at the lowest final concentration (12.5 μg/ml) had no protective effect against lipid peroxidation. The present results indicate that the extract from T. pallidum is likely to be a source of compounds with the antioxidative properties, useful in the prevention against the oxidative stress-related diseases.

  3. Platelet lipidomic.

    Science.gov (United States)

    Dolegowska, B; Lubkowska, A; De Girolamo, L

    2012-01-01

    Lipids account for 16-19 percent dry platelet matter and includes 65 percent phospholipids, 25 percent neutral lipids and about 8 percent glycosphingolipids. The cell membrane that surrounds platelets is a bilayer that contains different types phospholipids symmetrically distributed in resting platelets, such as phosphatidylserine (PS), phosphatidylethanolamine (PE), phosphatidylcholine, and sphingomyelin. The collapse of lipid asymmetry is exposure of phosphatidylserine in the external leaflet of the plasma bilayer, where it is known to serve at least two major functions: providing a platform for development of the blood coagulation cascade and presenting the signal that induces phagocytosis of apoptotic cells. During activation, this asymmetrical distribution becomes disrupted, and PS and PE become exposed on the cell surface. The transbilayer movement of phosphatidylserine is responsible for the platelet procoagulant activity. Exposure of phosphatidylserine is a flag for macrophage recognition and clearance from the circulation. Platelets, stored at room temperature for transfusion for more than 5 days, undergo changes collectively known as platelet storage lesions. Thus, the platelet lipid composition and its possible modifications over time are crucial for efficacy of platelet rich plasma therapy. Moreover, a number of substances derived from lipids are contained into platelets. Eicosanoids are lipid signaling mediators generated by the action of lipoxygenase and include prostaglandins, thromboxane A2, 12-hydroxyeicosatetraenoic acid. Isoprostanes have a chemical structure similar to this of prostanoids, but are differently produced into the particle, and are ligands for prostaglandins receptors, exhibiting biological activity like thromboxane A2. Endocannabinoids are derivatives from arachidonic acid which could reduce local pain. Phospholipids growth factors (sphingolipids, lysophosphatidic acid, platelet-activating factor) are involved in tissue

  4. Influence of red algal sulfated polysaccharides on blood coagulation and platelets activation in vitro.

    Science.gov (United States)

    Sokolova, Ekaterina V; Byankina, Anna O; Kalitnik, Alexandra A; Kim, Yong H; Bogdanovich, Larisa N; Solov'eva, Tamara F; Yermak, Irina M

    2014-05-01

    The influence of sulfated polysaccharides (λ-, κ-, and κ/β-carrageenan and porphyran) - on platelet activation was studied. Carrageenans were much weaker inhibitors of a coagulation process than heparin, while porphyran had not that effect. Results of the aPTT and PT assays suppose that carrageenans affected mostly intrinsic pathway of coagulation, while their effect on the extrinsic pathway is extremely low (λ and κ/β) or absent (κ, LMW derivative of κ-carrageenan). λ-Carrageenan was the most potent anticoagulant agent in TT, aPTT, PT, and anti-factor Xa activity. This sample was also the strongest inhibitor of collagen-induced platelet aggregation in PRP. Generally, the correlation of anticoagulant and antithrombotic action in PRP is preserved for carrageenans but not for heparin. Carrageenans and porphyran affected platelet adhesion to collagen by influencing glycoprotein VI. Low molecular weight κ-carrageenan had a similar effect on platelet adhesion mediated with both major collagen receptors: integrin α2 β1 and glycoprotein VI as native polysaccharide had. Carrageenans resulted in activation of platelets under platelet adhesion mediated by integrin αIIb β3 with less degree than heparin. The least sulfated κ/β-carrageenan that possessed an inhibiting effect on thrombin- and collagen-induced aggregation of washed platelets and on the PT test but it had no significant effect on TT was the weakest promoter of integrin αIIb β3 mediated platelet activation. In summary, our study showed that the polysaccharide action was complex, since it depended on its molecular mass, sulfation degree, and monosaccharide contents (3,6-anhydrogalactose).

  5. Metalloproteases Affecting Blood Coagulation, Fibrinolysis and Platelet Aggregation from Snake Venoms: Definition and Nomenclature of Interaction Sites

    Directory of Open Access Journals (Sweden)

    R. Manjunatha Kini

    2016-09-01

    Full Text Available Snake venom metalloproteases, in addition to their contribution to the digestion of the prey, affect various physiological functions by cleaving specific proteins. They exhibit their activities through activation of zymogens of coagulation factors, and precursors of integrins or receptors. Based on their structure–function relationships and mechanism of action, we have defined classification and nomenclature of functional sites of proteases. These metalloproteases are useful as research tools and in diagnosis and treatment of various thrombotic and hemostatic conditions. They also contribute to our understanding of molecular details in the activation of specific factors involved in coagulation, platelet aggregation and matrix biology. This review provides a ready reference for metalloproteases that interfere in blood coagulation, fibrinolysis and platelet aggregation.

  6. Metalloproteases Affecting Blood Coagulation, Fibrinolysis and Platelet Aggregation from Snake Venoms: Definition and Nomenclature of Interaction Sites

    Science.gov (United States)

    Kini, R. Manjunatha; Koh, Cho Yeow

    2016-01-01

    Snake venom metalloproteases, in addition to their contribution to the digestion of the prey, affect various physiological functions by cleaving specific proteins. They exhibit their activities through activation of zymogens of coagulation factors, and precursors of integrins or receptors. Based on their structure–function relationships and mechanism of action, we have defined classification and nomenclature of functional sites of proteases. These metalloproteases are useful as research tools and in diagnosis and treatment of various thrombotic and hemostatic conditions. They also contribute to our understanding of molecular details in the activation of specific factors involved in coagulation, platelet aggregation and matrix biology. This review provides a ready reference for metalloproteases that interfere in blood coagulation, fibrinolysis and platelet aggregation. PMID:27690102

  7. Bacillus pasteurii urease shares with plant ureases the ability to induce aggregation of blood platelets.

    Science.gov (United States)

    Olivera-Severo, D; Wassermann, G E; Carlini, C R

    2006-08-15

    Ureases (EC 3.5.1.5) are highly homologous enzymes found in plants, bacteria and fungi. Canatoxin, an isoform Canavalia ensiformis urease, has several biological properties unrelated to its ureolytic activity, like platelet-aggregating and pro-inflammatory effects. Here, we describe that Bacillus pasteurii urease (BPU) also induces aggregation of rabbit platelets, similar to the canatoxin-induced effect (ED(50) 0.4 and 0.015 mg/mL, respectively). BPU induced-aggregation was blocked in platelets pretreated with dexamethasone and esculetin, a phospholipase A(2) and a lipoxygenase inhibitor, respectively, while platelets treated with indomethacin, a cyclooxygenase inhibitor, showed increased response to BPU. Methoxyverapamil (Ca(2+) channel blocker) and AMP (ADP antagonist) abrogated urease-induced aggregation, whereas the PAF-acether antagonist Web2170 had no effect. We concluded that platelet aggregation induced by BPU is mediated by lipoxygenase-derived eicosanoids and secretion of ADP from the platelets through a calcium-dependent mechanism. Potential relevance of these findings for bacterium-plant interactions and pathogenesis of bacterial infections are discussed.

  8. Preparation, quality criteria, and properties of human blood platelet lysate supplements for ex vivo stem cell expansion.

    Science.gov (United States)

    Shih, Daniel Tzu-Bi; Burnouf, Thierry

    2015-01-25

    Most clinical applications of human multipotent mesenchymal stromal cells (MSCs) for cell therapy, tissue engineering, regenerative medicine, and treatment of immune and inflammatory diseases require a phase of isolation and ex vivo expansion allowing a clinically meaningful cell number to be reached. Conditions used for cell isolation and expansion should meet strict quality and safety requirements. This is particularly true for the growth medium used for MSC isolation and expansion. Basal growth media used for MSC expansion are supplemented with multiple nutrients and growth factors. Fetal bovine serum (FBS) has long been the gold standard medium supplement for laboratory-scale MSC culture. However, FBS has a poorly characterized composition and poses risk factors, as it may be a source of xenogenic antigens and zoonotic infections. FBS has therefore become undesirable as a growth medium supplement for isolating and expanding MSCs for human therapy protocols. In recent years, human blood materials, and most particularly lysates and releasates of platelet concentrates have emerged as efficient medium supplements for isolating and expanding MSCs from various origins. This review analyzes the advantages and limits of using human platelet materials as medium supplements for MSC isolation and expansion. We present the modes of production of allogeneic and autologous platelet concentrates, measures taken to ensure optimal pathogen safety profiles, and methods of preparing PLs for MSC expansion. We also discuss the supply of such blood preparations. Produced under optimal conditions of standardization and safety, human platelet materials can become the future 'gold standard' supplement for ex vivo production of MSCs for translational medicine and cell therapy applications.

  9. Assessment of the influence of the inflammatory process on the activation of blood platelets and morphological parameters in patients with ulcerative colitis (colitis ulcerosa

    Directory of Open Access Journals (Sweden)

    Halina Kemona

    2011-04-01

    Full Text Available Ulcerative colitis (colitis ulcerosa is a non-specific inflammatory bowel disease of unknown etiology. The symptoms which are observed in the course of ulcerative colitis are: an increase in the number of leukocytes and blood platelets, an increase in the concentration of IL-6 and anemia. Blood platelets are the key element, linking the processes of hemostasis, inflammation and the repair of damaged tissues. Activation of blood platelets is connected with changes in their shape and the occurrence of the reaction of release. P-selectin appears on the surfaces of activated blood platelets and the concentration level of soluble P-selectin increases in the blood plasma. The aim of this study was to define whether the increased number of blood platelets in patients with ulcerative colitis accompanies changes in their activation and morphology. A total of 16 subjects with ulcerative colitis and 32 healthy subjects were studied. Mean platelet count, morphological parameters of platelets and MPC were measured using an ADVIA 120 hematology analyzer. Concentrations of sP-selectin and IL-6 in serum were marked by immunoassay (ELISA. MPC, concentration of sP-selectin and IL-6 were significantly higher in subjects with ulcerative colitis compared to those in the healthy group. There was a decrease of MPV in patients with ulcerative colitis, which is statistically significant. Chronic inflammation in patients with ulcerative colitis causes an increase in the number of blood platelets, a change in their morphology and activation. Decreased MPV value reflects activation and the role blood platelets play in the inflammatory process of the mucous membrane of the colon. A high concentration of sP-selectin, which is a marker of blood platelet activation, demonstrates their part in the inflammatory process. The increase in the concentration of sP-selectin correlated positively with the increase in concentration of IL-6. This is why it may be a useful marker

  10. D-glucaro 1,4-lactone and resveratrol as antioxidants in blood platelets.

    Science.gov (United States)

    Olas, Beata; Saluk-Juszczak, Joanna; Wachowicz, Barbara

    2008-04-01

    The aim of our work was to study the anti-aggregatory and antioxidative effects of natural dietary products, D-glucaro 1,4-lactone (1,4-GL) in combination with phenolic compound resveratrol (trans-3,4',5-trihydroxystilbene). Our results in vitro showed that 1,4-GL alone slightly inhibits platelet aggregation induced by thrombin. The combination of resveratrol (0.1 microM) with 0.5 mM of 1,4-GL caused a significant decrease of thrombin-induced platelet aggregation; however separately, neither of studied compound at used concentrations was not effective. When platelets were treated with 1,4-GL (at the concentration of 0.1 mM and higher) and resveratrol (0.1 microM), similar synergistic action of both tested compound on markers of oxidative stress formation was observed. We measured the levels of different specific markers of oxidative stress, e.g., superoxide anion radicals O(2)(-)*, thiobarbituric acid-reactive substances and carbonyl group formation. Both tested compounds inhibited also the generation of O(2)(-)* and malondialdehyde that represents enzymatical peroxidation of arachidonic acid leading to thromboxane A(2) (TXA(2)) formation in platelets after thrombin stimulation. The obtained in vitro results demonstrate that anti-platelet and antioxidative properties of resveratrol may be significantly augmented by another dietary agent such as 1,4-GL, but mechanism synergistic action of these compounds is not yet known.

  11. Flow cytometric comparison of platelets from a whole blood and finger-prick sample: impact of 24 hours storage.

    Science.gov (United States)

    Swanepoel, Albe C; Stander, Andre; Pretorius, Etheresia

    2013-03-01

    In this study, we investigate the validity and laboratory utility of flow cytometry when analyzing platelet activation by studying CD41, CD42b, CD62P and CD63. We compare flow cytometry results from citrated whole-blood and finger-prick samples directly after collection and also after storing both a finger-prick and whole-blood sample for 24 hours. Citrated whole-blood and finger-prick samples were taken from three healthy individuals on two occasions, and a total of 60,000 cells were analyzed for each of the four phycoerythrin-labeled monoclonal antibodies. Half of each sample was analyzed immediately after sampling while the other half was kept in the fridge at 6 °C for 24 hours before analysis. No significant difference was found between the sampling methods or the period of time before analysis. Results therefore suggest that an appropriately prepared finger-prick sample can be used for platelet function analysis, and samples can be stored for 24 hours in the fridge at 6 °C before analysis.

  12. Shape changes induced by biologically active peptides and nerve growth factor in blood platelets of rabbits.

    OpenAIRE

    Gudat, F; Laubscher, A.; Otten, U; Pletscher, A

    1981-01-01

    1 Nerve growth factor (NGF), substance P (SP) and thymopoietin all caused shape change reactions of rapid onset in rabbit platelets. NGF had the highest maximal effect, and SP the lowest EC50 (concentration causing half maximal shape change). The action of SP was reversible within 5 min, whereas that of NGF lasted for at least 1 h. A series of other peptides were inactive. 2 After preincubation of platelets with SP, a second application of SP no longer caused a shape change reaction, whereas ...

  13. Platelet gene therapy corrects the hemophilic phenotype in immunocompromised hemophilia A mice transplanted with genetically manipulated human cord blood stem cells.

    Science.gov (United States)

    Shi, Qizhen; Kuether, Erin L; Chen, Yingyu; Schroeder, Jocelyn A; Fahs, Scot A; Montgomery, Robert R

    2014-01-16

    Our previous studies have demonstrated that platelet FVIII (2bF8) gene therapy can improve hemostasis in hemophilia A mice, even in the presence of inhibitory antibodies, but none of our studies has targeted human cells. Here, we evaluated the feasibility for lentivirus (LV)-mediated human platelet gene therapy of hemophilia A. Human platelet FVIII expression was introduced by 2bF8LV-mediated transduction of human cord blood (hCB) CD34(+) cells followed by xenotransplantation into immunocompromised NSG mice or NSG mice in an FVIII(null) background (NSGF8KO). Platelet FVIII was detected in all recipients that received 2bF8LV-transduced hCB cells as long as human platelet chimerism persisted. All NSGF8KO recipients (n = 7) that received 2bF8LV-transduced hCB cells survived tail clipping if animals had greater than 2% of platelets derived from 2bF8LV-transduced hCB cells, whereas 5 of 7 survived when human platelets were 0.3% to 2%. Whole blood clotting time analysis confirmed that hemostasis was improved in NSGF8KO mice that received 2bF8LV-transduced hCB cells. We demonstrate, for the first time, the feasibility of 2bF8LV gene delivery to human hematopoietic stem cells to introduce FVIII expression in human platelets and that human platelet-derived FVIII can improve hemostasis in hemophilia A.

  14. Decreased blood platelet volume and count in patients with liver disease

    DEFF Research Database (Denmark)

    Jørgensen, B; Fischer, E; Ingeberg, S;

    1984-01-01

    Mean platelet volume (MPV) and count (PLT) were assessed in patients with moderately affected liver function. PLT was significantly decreased in patients with liver disease (197 X 10(9)l-1 +/- 87 (SD), no. = 79) compared with that of controls (273 X 10(9)l-1 +/- 53 (SD), no. = 37, P less than 0...

  15. Effects of polyphenol-rich extract from berries of Aronia melanocarpa on the markers of oxidative stress and blood platelet activation.

    Science.gov (United States)

    Olas, Beata; Kedzierska, Magdalena; Wachowicz, Barbara; Stochmal, Anna; Oleszek, Wieslaw

    2010-01-01

    Bioactive substances found in numerous foods can be successfully and safely used to modify various cellular functions and affect the oxidative stress. Aronia melanocarpa fruits (Rosaceae) are one of the richest plant sources of phenolic substances shown to have anti-inflammatory, antitumor, antioxidative and antiplatelet activities. We investigated antioxidant properties of the extract from berries of A. melanocarpa by the estimation of the selected and other biomarkers of oxidative stress, i.e. the level of 8-epi-prostaglandin F(2) (8-EPI) (by immunoassay kit) and the amount of glutathione (by HPLC method) in control platelets and platelets treated with H(2)O(2). The expression of alpha(IIb)beta(3) (a marker of platelet activation) was measured by flow cytometer. The antioxidative and antiplatelet properties of the tested extract were also compared with the action of a well characterized antioxidative and antiplatelet commercial monomeric polyphenol-resveratrol. The extract from berries of A. melanocarpa (at the highest tested concentration -100 microg/ml) decreased the production of 8-EPI (a marker of lipid peroxidation) in control blood platelets and platelets treated with H(2)O(2) (2 mM). A combined action of the tested plant extract and H(2)O(2) evoked a significant increase of reduced form of glutathione in platelets compared with cells treated with H(2)O(2) only. Moreover, the tested plant extract (at the highest used concentration -100 microg/ml) reduced the expression of alpha(IIb)beta(3) on blood platelets. Comparative studies indicate that the tested plant extract was found to be more reactive in blood platelets than the solution of pure resveratrol.

  16. 献血者血小板数量及血容量对机采血小板采集量的影响%The Influence on Apheresis Platelets Collection Quantity of Platelets Counts and Blood Volume of Donors

    Institute of Scientific and Technical Information of China (English)

    蒋靓; 曹维娟; 王明元

    2014-01-01

    目的:分析献血员血小板数量及处理血量对机采血小板采集量的影响。方法应用Trima血细胞分离机采集100名献血者的双份血小板。结果通过多元回归分析发现,献血者采前的血小板计数(Plt)和血容量(BV)与血小板采集量之间存在回归关系,其标准偏回归系数β值分别为-0.370和-0.201,P<0.01。结论对采前的Plt和BV水平较低的献血者,可采用Trima血细胞分离机进行采集。%Objective To analyze the influence on apheresis platelets collection quantity of platelets count (Plt) and blood volume (BV) of donors. Methods Double platelets were collected from 100 donors using the Trima blood separator. Results By multivariate linear regression analysis, it was found that there were regression relationships between donors' Plt and BV before donation and platelets collection quantity (β=-0.370 and-0.201, P<0.01). Conclusion For donors with low level Plt or BV, Trima blood separator can be used.

  17. Platelet Donation

    Science.gov (United States)

    ... For Hospitals Home > Platelet Donation Printable Version Platelet Donation Sign Up to Donate Platelets Everything you need ... Platelets Explained in Two Minutes Why Your Platelet Donation Matters Cassie Brabb descibes how it felt to ...

  18. Consistency and proportionality in policy decision-making in blood safety: the case for an all-apheresis platelet supply in Germany.

    Science.gov (United States)

    Vamvakas, E C; Hitzler, W E

    2013-01-01

    Recently, German investigators presented the first mathematical model finding a significant increase in the risk of HIV, HCV, and HBV transmission when pools of 4 whole-blood-derived buffy-coat platelets, rather than 1 single-donor (apheresis) component, are used to provide one platelet dose. Based, in both cases, on mathematical models employing the incidence/window-period method, the relative risk of transmission from pooled versus apheresis platelets (2.2 or 2.75 for HIV, 2.7 or 3.375 for HCV, and 3.2 or 4.0 for HBV, with pools of 4 or 5 concentrates, respectively) is similar to the difference in risk before (versus after) introduction of HIV-1 and HCV RNA screening. The absolute increase in the risk from pools (1 to 2 HIV-, HCV-, or HBV-infectious platelet doses annually) is much smaller than the yield from HIV-1 and HCV RNA screening projected in the 1990s, but it becomes similar to that yield (with up to 88 infectious platelet doses intercepted) when we consider the next transfusion-transmitted pathogen to emerge in the future. Although pathogen reduction (PR) of platelets would eliminate the difference in risk between pooled and apheresis platelets vis-a-vis viral transmission, PR is not ready for implementation because the safety of PR needs to be investigated further. German transfusion guidelines should be revised to indicate the difference in risk associated with pooled versus apheresis platelets, and transition toward an all-apheresis platelet supply should commence. These actions are consistent with and proportionate to the action taken in the 1990s when screening for HIV-1 and HCV RNA was implemented.

  19. Comparison of platelet clumping and complete blood count results with Sysmex XT-2000iV in feline blood sampled on EDTA or EDTA plus CTAD (citrate, theophylline, adenosine and dipyridamole).

    Science.gov (United States)

    Granat, Fanny; Geffré, Anne; Braun, Jean-Pierre; Trumel, Catherine

    2011-12-01

    False thrombocytopenia may result from platelet aggregation, especially in feline ethylenediamine tetra-acetic acid (EDTA) blood specimens. Citrate, theophylline, adenosine and dipyridamole (CTAD) was added to 46 feline EDTA specimens to test its anti-aggregation action. Platelet aggregation was estimated from blood films and a complete blood count was performed with a Sysmex XT-2000iV analyser. Platelet aggregation score was >2 in 11/46 EDTA tubes and only in one EDTA+CTAD specimen. The platelet count was higher in all CTAD-supplemented tubes except one, medians measured by cytometry being 225.5 × 10(9)/l and 249.0 × 10(9)/l in EDTA and EDTA+CTAD, respectively (P = 0.007). Adding CTAD had statistically and analytically significant but moderate effects on other blood variables, the most intense variations being observed for reticulocytes (about 3% higher in EDTA specimens) and reticulocyte indexes. Addition of CTAD to EDTA when sampling feline blood is a useful option to reduce platelet clumping.

  20. Evaluation of the correlation between pH and MPV platelet concentrates prepared in Tirana Blood Transfusion Center.

    Directory of Open Access Journals (Sweden)

    MERITA XHETANI

    2014-06-01

    Full Text Available The quality of platelet concentrates is an important option in transfusion therapy. pH and platelet indices have been found to be valuable parameters for monitoring the in vitro quality of platelet concentrates. Platelet activation which leads to loss of its functionality has been demonstrated by changes in those two parameters. The aim of the study was to evaluate the correlation between pH and mean platelet volume (MPV in platelet concentrates in order to examine the quality of platelet concentrate. 150 units of platelet concentrates were produced by platelet reach plasma (PRP, and stored for 5 days. Then MPV and pH were analyzed by automated hematological cell counter and Ph meter respectively. Regression analysis showed that there was a significant influence of pH changes on the changes in MPV. On the other hand, increase in pH lead to decrease in MPV. Storing platelet concentrates up to 5 days may stimulate platelet activity, enhancing its size and resulted in its destruction, so the remaining platelet are those with significantly lower MPV. Also platelet activation was those with an increase in pH. As a result measurements of MPV and pH have a great potential as quality markers of platelet concentrates.

  1. Synergistic effects of high blood cholesterol and hypertension on leukocyte and platelet recruitment in the cerebral microcirculation.

    Science.gov (United States)

    Rodrigues, Stephen F; Almeida-Paula, Lidiana D; Granger, Daniel N

    2014-04-01

    Hypertension or hypercholesterolemia can induce a proinflammatory and prothrombogenic phenotype in the microcirculation of the brain; however, less is known about how the combination of these risk factors affects the vasculature. We recently reported that a moderate (60%) increase in plasma cholesterol blunts the recruitment of leukocytes and platelets in the cerebral microvessels elicited by hypertension. In this study, we examined whether larger increments in blood cholesterol (4-fold) exerts a similar modulating influence on the vasculature in the presence of hypertension. Apolipoprotein E-knockout mice with deoxycorticosterone acetate salt-induced hypertension were placed on a high-cholesterol diet and exhibited exaggerated leukocyte and platelet adhesion responses in cerebral microvessels. Intermittent feeding (every fourth day) with high-cholesterol diet yielded similar phenotypic changes in the vasculature. Once the mice were placed on high-cholesterol diet, 4 days on normal diet (ND) were needed to revert to a normal vascular phenotype. Angiotensin II type 1 receptors and reactive oxygen species seem to contribute to the vascular responses induced by hypercholesterolemia and hypertension. Our findings indicate that the combination of hypertension and large increases in plasma cholesterol concentration results in a severe, but reversible, inflammatory and thrombogenic phenotype in the cerebral microvasculature.

  2. Types of Blood Donations

    Science.gov (United States)

    ... blood' every 56 days. Back to Top Platelet Apheresis Platelet donations are collected at select American Red ... about Platelet Apheresis Donations » Back to Top Plasma Apheresis Plasma is collected simultaneously with a platelet donation ...

  3. Small for Gestational Age and Magnesium in Cord Blood Platelets: Intrauterine Magnesium Deficiency May Induce Metabolic Syndrome in Later Life

    Directory of Open Access Journals (Sweden)

    Junji Takaya

    2011-01-01

    Full Text Available Magnesium deficiency in pregnancy frequently occurs because of inadequate or low intake of magnesium. Magnesium deficiency during pregnancy can induce not only maternal and fetal nutritional problems, but also consequences that might last in offspring throughout life. Many epidemiological studies have disclosed that small for gestational age (SGA is associated with an increased risk of insulin resistance in adult life. We reported that intracellular magnesium of cord blood platelets is lower in SGA groups than that in appropriate for gestational age groups, suggesting that intrauterine magnesium deficiency may result in SGA. Taken together, intrauterine magnesium deficiency in the fetus may lead to or at least program insulin resistance after birth. In this review, we propose that intrauterine magnesium deficiency may induce metabolic syndrome in later life. We discuss the potential contribution of aberrant magnesium regulation to SGA and to the pathogenesis of metabolic syndrome.

  4. Effect of some saturated and unsaturated fatty acids on prostaglandin biosynthesis in washed human blood platelets from (1-/sup 14/ C)arachidonic acid

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, K.C.; Awasthi, K.K.; Lindegard, P.; Tiwari, K.P.

    1982-03-01

    The effects of some saturated (lauric, palmitic and stearic) an unsaturated (linoleic, gamma-linolenic, alpha-linolenic and oleic) fatty acids at 0.1. 0.25 and 0.5 mM concentrations on the in vitro metabolization of (1-14 C) arachidonic acid by washed human blood platelets have been studied. Effects of these fatty acids were studied with intact as well as lysed platelet preparations. With intact platelet preparations it was found that (i) all unsaturated fatty acids enhanced the biosynthesis of TxB2, PGE2, PGD2 and PGF2 alpha, (ii) unsaturated fatty acids reduced the formation of HHT and HETE with the exception of oleic acid which showed very little effect, (iii) unsaturated fatty acids reduced the formation of MDA, whereas palmitic and stearic acids increased its formation and (iv) all unsaturated fatty acids reduced the synthesis of prostaglandin endoperoxides. These results support our previous observations where effects of fatty acids were examined at higher concentrations (10). At 0.1 mM FA concentration, inconsistent results were obtained. With lysed platelet preparations all cyclooxygenase products were reduced in presence of unsaturated fatty acids, whereas HETE formation was reduced only in presence of linoleic and gamma-linolenic acids. Electron micrographs of washed platelet suspensions were obtained with untreated platelet preparations and platelet preparations treated with 0.25 and 0.5 mM linoleic acid concentrations. The results are discussed in the light of a possible soap-like effect of FA salt on platelets.

  5. Homocysteine is a novel risk factor for suboptimal response of blood platelets to acetylsalicylic acid in coronary artery disease: a randomized multicenter study.

    Science.gov (United States)

    Karolczak, Kamil; Kamysz, Wojciech; Karafova, Anna; Drzewoski, Jozef; Watala, Cezary

    2013-08-01

    The incomplete inhibition of platelet function by acetylsalicylic acid (ASA), despite the patients are receiving therapeutic doses of the drug ('aspirin-resistance'), is caused by numbers of risk factors. In this study we verified the idea that plasma homocysteine (Hcy) contributes to 'aspirin-resistance' in patients with coronary artery disease (CAD) and with or without type 2 diabetes mellitus (T2DM). A cross-designed randomized controlled intervention study has been performed (126 CAD pts incl. 26 with T2DM) to determine whether increasing ASA dose from 75mg to 150mg daily may result in the increased antiplatelet effect, in the course of four-week treatment. Platelet response to collagen (coll) or arachidonic acid (AA) was monitored with whole blood aggregometry, plasma thromboxane (Tx), and Hcy levels were determined immunochemically. The ASA-mediated reductions in platelet response to coll (by 12±3%) or AA (by 10±3%) and in plasma Tx (by 20±9%; p<0.02 or less) were significantly greater for higher ASA dose and significantly correlated with plasma Hcy, which was significantly lower in "good" ASA responders compared to "poor" responders (p<0.001). Higher plasma Hcy appeared a significant risk factor for blood platelet refractoriness to low ASA dose (OR=1.11; ±95%CI: 1.02-1.20, p<0.02, adjusted to age, sex and CAD risk factors). Hcy diminished in vitro antiplatelet effect of low ASA concentration and augmented platelet aggregation (by up to 62% (p<0.005) for coll and up to 15% (p<0.005) for AA), whereas its acetyl derivative acted oppositely. Otherwise, Hcy intensified antiplatelet action of high ASA. Hyperhomocysteinaemia may be a novel risk factor for the suppressed blood platelet response to ASA, and homocysteine may act as a specific sensitizer of blood platelets to some agonists. While homocysteine per se acts as a proaggregatory agent to blood platelets, its acetylated form is able to reverse this effect. Thus, these findings reveal a possibly new

  6. Red Blood Cell Distribution Width and the Platelet Count in Iron-deficient Children Aged 0.5-3 Years.

    Science.gov (United States)

    Akkermans, M D; Uijterschout, L; Vloemans, J; Teunisse, P P; Hudig, F; Bubbers, S; Verbruggen, S; Veldhorst, M; de Leeuw, T G; van Goudoever, J B; Brus, F

    2015-01-01

    Early detection of iron deficiency (ID) and iron deficiency anemia (IDA) in young children is important to prevent impaired neurodevelopment. Unfortunately, many biomarkers of ID are influenced by infection, thus limiting their usefulness. The aim of this study was to investigate the value of red blood cell distribution width (RDW) and the platelet count for detecting ID(A) among otherwise healthy children. A multicenter prospective observational study was conducted in the Netherlands to investigate the prevalence of ID(A) in 400 healthy children aged 0.5-3 years. ID was defined as serum ferritin (SF) count were determined in the complete blood cell count. RDW was inversely correlated with SF and not associated with CRP. Calculated cutoff values for RDW to detect ID and IDA gave a relatively low sensitivity (53.1% and 57.1%, respectively) and specificity (64.7% and 69.9%, respectively). Anemic children with a RDW >14.3% had a 2.7 higher odds (95% confidence interval [CI]: 1.2-6.3) to be iron deficient, compared with anemic children with a RDW count showed a large range in both ID and non-ID children. In conclusion, RDW can be helpful for identifying ID as the cause of anemia in 0.5- to 3-year-old children, but not as primary biomarker of ID(A). RDW values are not influenced by the presence of infection. There appears to be no role for the platelet count in diagnosing ID(A) in this group of children.

  7. Is Platelet-rich plasma superior to whole blood in the management of chronic tennis elbow: one year randomized clinical trial

    OpenAIRE

    Raeissadat, Seyed Ahmad; Rayegani, Seyed Mansoor; Hassanabadi, Hossein; Rahimi, Rosa; Sedighipour, Leyla; Rostami, Khalil

    2014-01-01

    Background Lateral humeral epicondylitis, or ‘tennis elbow’, is a common condition with a variety of treatment options. Platelet-rich plasma (PRP) and Autologous Whole Blood (AWB) represent new therapeutic options for chronic tendinopathies including tennis elbow. The aim of the present study was to compare the long term effects of PRP versus autologous whole blood local injection in patients with chronic tennis elbow. Methods Seventy six patients with chronic lateral humeral epicondylitis wi...

  8. Platelets and hemostasis

    Directory of Open Access Journals (Sweden)

    M. A. Panteleev

    2014-09-01

    Full Text Available Platelets are anuclear cell fragments playing important role in hemostasis, termination of bleeding after damage, as well as in pathological thrombus formation. The main action of platelets is the formation of aggregates, overlapping the injury. They obtained the ability to aggregate by the transition process called activation. Despite the relatively simple and definite function platelet structure is very difficult: they have almost a full set of organelles, including the endoplasmic reticulum, mitochondria and other entities. When activated platelets secrete various granules interact with plasma proteins and red blood cells and other tissues. Their activation is controlled by multiple receptors and complex signaling cascades. In this review platelet structure, mechanisms of its functioning in health and disease, diagnostic methods of platelet function and approaches to their correction were considered. Particular attention will be given to those areas of the science of platelets, which still lay hidden mysteries.

  9. Study on Relativity of Platelet Count of Platelet-rich Plasma and Platelet Count,Hematocrit of Whole Blood%富血小板血浆血小板浓度与全血血小板浓度和红细胞比容相关性探讨

    Institute of Scientific and Technical Information of China (English)

    李祖兰; 任军伟; 丛玉隆; 白洁; 邓新立; 马长生; 陈兴明; 杨亮程; 王海立

    2012-01-01

    目的 探讨富血小板血浆(PRP)血小板浓度与全血血小板浓度、红细胞比容(HCT)相关性.方法 随机收集162例门诊体检志愿者静脉血标本,以EDTA-K2,枸橼酸钠抗凝.枸橼酸钠抗凝血800 r/min(离心半径19 cm)离心5 min,分离富含血小板血浆(PRP),应用Sysmex XE-2100血液分析仪测定全血血小板浓度(X1)和HCT(X2),PRP血小板浓度(Y).以HCT 0.35为界,将数据分为正常组和低值组.结果 所得数据采用多元相关性统计分析得到回归方程Y总=1.309 51X1 +744.294 5X2-262.068(R2 =0.897 8);Y正常组=1.380 208X1 +855.884 8X2-323.374(R2=0.892 9);Y低值组=1.088 972X1 +465.228 8X2-123.101(R2=0.961 1).结论 全血血小板浓度、红细胞比容与富血小板血浆血小板浓度相关显著,由全血血小板浓度和红细胞比容可初步推算富血小板血浆血小板浓度.%Objective To explore relativity of platelet count of platelet-rich plasma, platelet count and hematocrit of whole blood. Methods Venous blood sample of outpatient volunteers were collected and anticoagulaged by EDTA-K2 and sodium citrate(n=162) ,and platelet-rich plasma(PRP) was obtained by centrifuging the blood anticoagulaged by sodium citrate at a low speed (800 r/min, r=19 cm) for 5 minute, then platelet number of PRP(Y) ,platelet number (X1 ) and hematocrit (X2) of whole blood were detected by Sysmex XE-2100 blood analyzer. The data was divided into normal and low group by 0. 35 of hematocrit. Results Regression equation analysed by multiple linear regression: Ytotal = 1.309 51X1 +744.294 5X2 - 262. 068(R2= 0.897 8) ;Ynormal= l. 380 208 X1+855. 884 8X2 -323. 374(R2 =0. 892 9);Ylow = l. 088 972X,+465. 228 8 X2 - 123. 101(R2 =0. 961 1). Conclusion Platelet count of the platelet-rich plasma,platelet count and hematocrit of the whole blood seem to relate significantly, and platelet count of platelet-rich plasma could be estimated approximately by platelet count and hematocrit of the whole blood.

  10. Effects of the commercial extract of aronia on oxidative stress in blood platelets isolated from breast cancer patients after the surgery and various phases of the chemotherapy.

    Science.gov (United States)

    Kedzierska, Magdalena; Olas, Beata; Wachowicz, Barbara; Glowacki, Rafal; Bald, Edward; Czernek, Urszula; Szydłowska-Pazera, Katarzyna; Potemski, Piotr; Piekarski, Janusz; Jeziorski, Arkadiusz

    2012-03-01

    Since the extract from berries of Aronia melanocarpa presents antioxidative properties in plasma and in blood platelets, not only from healthy group, but also from patients with benign breast diseases and in patients with invasive breast cancer before surgery, the aim of our present study was to evaluate the oxidative stress by measuring the level of various biomarkers of this process such as the generation of superoxide anion radicals (O(2)(-·)), the amount of carbonyl groups and 3-nitrotyrosine in proteins or the amount of glutathione in blood platelets isolated from breast cancer patients after the surgery and after various phases of the chemotherapy in the presence of A. melanocarpa extract (Aronox) in vitro. We demonstrated in platelet proteins from patients with invasive breast cancer (after the surgery and after various phases of the chemotherapy) higher level of carbonyl groups than in control healthy group. The level of 3-nitrotyrosine in platelet proteins from patients with invasive breast cancer was also significantly higher than in healthy subject group. We observed an increase of other biomarkers of oxidative stress such as O(2)(-·) and a decrease of GSH in platelets from patients with breast cancer (after the surgery and after various phases of the chemotherapy) compared to the healthy group. In model system in vitro our results showed that the commercial extract from berries of A. melanocarpa due to antioxidant action, significantly reduced the oxidative/nitrative stress in platelets from patients with invasive breast cancer caused by the surgery and various phases of the chemotherapy.

  11. Influence of acceleration voltage on scanning electron microscopy of human blood platelets.

    Science.gov (United States)

    Pretorius, E

    2010-03-01

    Scanning electron microscopy (SEM) is used to view a variety of surface structures, molecules, or nanoparticles of different materials, ranging from metals, dental and medical instruments, and chemistry (e.g. polymer analysis) to biological material. Traditionally, the operating conditions of the SEM are very important in the material sciences, particularly the acceleration voltage. However, in biological sciences, it is not typically seen as an important parameter. Acceleration voltage allows electrons to penetrate the sample; thus, the higher the acceleration voltage the more penetration into the sample will occur. As a result, ultrastructural information from deeper layers will interfere with the actual surface morphology that is seen. Therefore, ultimately, if acceleration voltage is lower, a better quality of the surface molecules and structures will be produced. However, in biological sciences, this is an area that is not well-documented. Typically, acceleration voltages of between 5 and 20 kV are used. This manuscript investigates the influence of acceleration voltages ranging from 5 kV to as low as 300 V, by studying surface ultrastructure of a human platelet aggregate. It is concluded that, especially at higher magnifications, much more surface detail is visible in biological samples when using an acceleration voltage between 2 kV and 300 V.

  12. Rheology Research of Red Blood Cell and Platelet in Elderly Patients During Perioperation%老年患者围术期红细胞、血小板流变性的研究

    Institute of Scientific and Technical Information of China (English)

    朱剑锋

    2002-01-01

    Objective To investigate the rheological changes of red blood cell and platelet and their clinical significant in elderlypatients. Methods Take preoperative and postoperative blood from the finger tip of 37 elderly patients and observe the clumping, fluidity,plastic of red blood cells and clumping of platelet with variable project microscope. Then calculate the intergral numbers and compare themwith that of adults. Results The numbers of the clumping, fluidity, plastic of red blood cells and clumping of platelet were increased afteroperation (P < 0.01 ). Compared to elderly patients, the clumping, fluidity, plastic of red blood cells and clumping of platelet in adultpatients were 1ow (P<0.05). There was no different rheology in two group before operation (P>0.05).Conclution There was distincttrouble of rhenlogy in patients during perioperation, especial in elderly patents.

  13. Studies on megakaryopoiesis and platelet function

    OpenAIRE

    Meinders, M.

    2015-01-01

    Platelets are blood circulating specialized subcellular fragments, which are produced by megakaryocytes. Platelets are essential for hemostasis and wound healing but also play a role in non-hemostatic processes such as the immune response or cancer metastasis. Considering the immediate precursors of platelets, normal megakaryocyte development is essential for normal platelet function. Although much is known about platelet development, some aspects of platelet production remain poorly understo...

  14. Platelet activation and aggregation

    DEFF Research Database (Denmark)

    Jensen, Maria Sander; Larsen, O H; Christiansen, Kirsten

    2013-01-01

    This study introduces a new laboratory model of whole blood platelet aggregation stimulated by endogenously generated thrombin, and explores this aspect in haemophilia A in which impaired thrombin generation is a major hallmark. The method was established to measure platelet aggregation initiated...

  15. Platelet alloimmunization after transfusion

    DEFF Research Database (Denmark)

    Taaning, E; Simonsen, A C; Hjelms, E;

    1997-01-01

    BACKGROUND AND OBJECTIVES: The frequency of platelet-specific antibodies after one series of blood transfusions has not been reported, and in multiply transfused patients is controversial. MATERIALS AND METHODS: We studied the frequency of alloimmunization against platelet antigens in 117 patient...

  16. Classical scrapie prions in ovine blood are associated with B lymphocytes and platelets-rich plasma

    Science.gov (United States)

    Classical scrapie is a naturally occurring fatal brain disease of sheep and goats which is caused by prions, a novel class of infectious agent, and is accompanied by the accumulation of abnormal isoforms of prion protein (PrP-Sc) in certain neural and lymphoid tissues. Although collection of a blood...

  17. Platelets as delivery systems for disease treatments

    OpenAIRE

    Shi, Qizhen; Montgomery, Robert R.

    2010-01-01

    Platelets are small, anucleate, discoid shaped blood cells that play a fundamental role in hemostasis. Platelets contain a large number of biologically active molecules within cytoplasmic granules that are critical to normal platelet function. Because platelets circulate in blood through out the body, release biological molecules and mediators on demand, and participate in hemostasis as well as many other pathophysiologic processes, targeting expression of proteins of interest to platelets an...

  18. In vitro function of random donor platelets stored for 7 days in composol platelet additive solution

    Directory of Open Access Journals (Sweden)

    Gupta Ashish

    2011-01-01

    Full Text Available Background and Aim: Platelets are routinely isolated from whole blood and stored in plasma for 5 days. The present study was done to assess the in vitro function of random donor platelets stored for 7 days in composol platelet additive solution at 22°C. Materials and Methods: The study sample included 30 blood donors of both sex in State Blood Bank, CSM Medical University, Lucknow. Random donor platelets were prepared by platelet rich plasma method. Whole blood (350 ml was collected in anticoagulant Citrate Phosphate Dextrose Adenine triple blood bags. Random donor platelets were stored for 7 days at 22°C in platelet incubators and agitators, with and without additive solution. Results: Platelet swirling was present in all the units at 22°C on day 7, with no evidence of bacterial contamination. Comparison of the mean values of platelet count, platelet factor 3, lactate dehydrogenase, pH, glucose and platelet aggregation showed no significant difference in additive solution, whereas platelet factor 3, glucose and platelet aggregation showed significant difference (P < 0.001 on day 7 without additive solution at 22°C. Conclusion: Our study infers that platelet viability and aggregation were best maintained within normal levels on day 7 of storage in platelet additive solution at 22°C. Thus, we may conclude that in vitro storage of random donor platelets with an extended shelf life of 7 days using platelet additive solution may be advocated to improve the inventory of platelets.

  19. Acetaminophen and Meloxicam Inhibit Platelet Aggregation and Coagulation in Blood Samples from Humans

    Science.gov (United States)

    2014-01-01

    participant was sampled once with a total of 100-ml blood volume. Exclusion criteria included pregnancy, on- going therapeutic anticoagulation , and use...of thromboxane A2 (TxA2) from prostaglandin H2, which is generated from arachidonic acid by cyclo-oxygenase (COX-1). The antiplatelet effects of...is acetaminophen? Some practical cautions with this widely used agent . Clin Pediatr (Phila) 1973; 12:692– 696. 3 Whyte IM, Buckley NA, Reith DM

  20. The effect of polyphenolic-polysaccharide conjugates from selected medicinal plants of Asteraceae family on the peroxynitrite-induced changes in blood platelet proteins.

    Science.gov (United States)

    Saluk-Juszczak, Joanna; Pawlaczyk, Izabela; Olas, Beata; Kołodziejczyk, Joanna; Ponczek, Michal; Nowak, Pawel; Tsirigotis-Wołoszczak, Marta; Wachowicz, Barbara; Gancarz, Roman

    2010-12-01

    Lots of plants belonging to Asteraceae family are very popular in folk medicine in Poland. These plants are also known as being rich in acidic polysaccharides, due to the presence of hexuronic acids or its derivatives. Our preliminary experiments have shown that the extract from Conyza canadensis L. possesses various biological activity, including antiplatelet, antiocoagulant and antioxidant properties. The aim of our study was to assess if macromolecular glycoconjugates from selected herbal plants of Asteraceae family: Achillea millefolium L., Arnica montana L., Echinacea purpurea L., Solidago virgaurea L., Chamomilla recutita (L.) Rauschert., and Conyza canadensis L. protect platelet proteins against nitrative and oxidative damage induced by peroxynitrite, which is responsible for oxidative/nitrative modifications of platelet proteins: the formation of 3-nitrotyrosine and carbonyl groups. These modifications may lead to changes of blood platelet functions and can have pathological consequences. The role of these different medicinal plants in the defence against oxidative/nitrative stress in human platelets is still unknown, therefore the oxidative damage to platelet proteins induced by peroxynitrite and protectory effects of tested conjugates by the estimation of carbonyl group level and nitrotyrosine formation (a marker of protein nitration) were studied in vitro. The antioxidative properties of the polyphenolic-polysaccharide conjugates from selected tested medicinal plants were also compared with the action of a well characterized antioxidative commercial polyphenol - resveratrol (3,4',5-trihydroxystilbene). The obtained results demonstrate that the compounds from herbal plants: A. millefolium, A. montana, E. purpurea, C. recutita, S. virgaurea, possess antioxidative properties and protect platelet proteins against peroxynitrite toxicity in vitro, similar to the glycoconjugates from C. canadensis. However, in the comparative studies, the polyphenolic

  1. 多次捐献机采血小板后献血者外周血象的变化%The changes of peripheral blood indexes in donors donating blood several times for apheresis platelet concentrates*

    Institute of Scientific and Technical Information of China (English)

    葛健民; 赵宏祥; 任素玲; 袁秀珍

    2011-01-01

    Objective To study the changes of peripheral blood several times indexes in donors donating blood for apheresis platelet concentrates. Methods 20 donors who donated blood for apheresis platelet concentrates 10 38 times (interval: 1- 2 months), were enrolled and detected for peripheral blood indexes respectively before the first and the last time for donating platelet,and the results were analyzed. Results Of all enrolled donors, the platelet number, red blood cell number, white blood cell number and haemoglobin concentrates and the average value before the last donating blood were not statistical different with those before the first donating(P>0.05) ,but mean platelet volume and platelet large cell rate were decreased(P<0.01). Conclusion Blood do nation could promote hematopoiesis of the bone marrow,and might not be harmful to the body health.%目的 研究多次捐献机采血小板后献血者外周血象的变化情况.方法 选择20名自愿捐献机采血小板达10~38次的献血者(每次间隔期为1~2个月),在首次和末次采集血小板前分别进行外周血象的检测,进行统计分析.结果 多次捐献机采血小板的献血者,末次采集前外周血小板数(PLT)与首次采集前PLT、正常值均数相比,差异均无统计学意义(P>0.05),外周血中的红细胞数(RBC)、白细胞数(WBC)、血红蛋白浓度(Hb)并未发生明显的变化,但血小板分布宽度(PDW)增加,血小板平均体积(MPV)、大形血小板比例(P-LCR)下降,且差异有统计学意义(P<0.01).结论 献血可以促进骨髓的造血功能,对机体并无明显不利的影响.

  2. Irradiation process of platelets and red blood cells: uncertainty values; Processo de irradiacao de bolsas contendo plaquetas e hemacias: fontes de incertezas

    Energy Technology Data Exchange (ETDEWEB)

    Pacifico, Leonardo, E-mail: leonardocpacifico@gmail.com [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil); Peixoto, Jose Gullherme P. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2016-07-01

    Irradiation of platelets and red blood cells is critical to prevent a disease called transfusion-associated graft versus host disease (TA-GVHD). An irradiator with source of Cesio-137 is used for this. During the irradiation process, input quantities contributing to the expanded uncertainty of the value of absorbed dose shown. The aim of our study was to identify the input quantities in the process. (author)

  3. Partial purification of the 5-hydroxytryptophan-reuptake system from human blood platelets using a citalopram-derived affinity resin

    Energy Technology Data Exchange (ETDEWEB)

    Biessen, E.A.L; Horn, A.S.; Robillard, G.T. (Univ. of Groningen (Netherlands))

    1990-04-03

    This paper describes a procedure for the synthesis and application of a citalopram-derived affinity resin in purifying the 5HT-reuptake system from human blood platelets. A two-step scheme has been developed for partial purification, based on wheat germ agglutinin-lectin (WGA) affinity and citalopram affinity chromatographies. Upon solubilization of the carrier with 1% digitonin, a 50-70-fold increase in specific ({sup 3}H) imipramine binding activity with a 70% recovery could be accomplished through WGA-lectin chromatography. The WGA pool was then subjected to affinity chromatography on citalopram-agarose. At least 90% of the binding capacity adsorbed to the column. Specific elution using 10 {mu}M citalopram resulted in a 22% recovery of binding activity. A 10,000-fold overall purification was obtained by using this two-step procedure. Analysis of the fractions on SDS-PAGE after {sup 125}I labeling revealed specific elution of 78- and 55-kDa proteins concomitant with the appearance of ({sup 3}H) imipramine binding activity. The pharmacological profile of the partially purified reuptake system correlated well with that derived from the crude membrane-bound reuptake system, suggesting a copurification of the 5HT binding activity and ({sup 3}H)imipramine binding activity.

  4. Lack of the specific influence of histamine and histamine H1, H2 and H3 receptor ligands on the serotonin uptake and release in rat blood platelets.

    Science.gov (United States)

    Pawlak, D; Malinowska, B; Wollny, T; Godlewski, G; Buczko, W

    1996-01-01

    This work was designed to investigate the influence of histamine, and H1 receptor agonist 2-(2-thiazolyl)ethylamine, H2 receptor agonist dimaprit and H3 receptor agonist R-(-)-alpha-methylhistamine on the serotonin uptake and release in rat blood platelets. Histamine and R-(-)-alpha-methylhistamine (up to 1 mmol/l), 2-(2-thiazolyl)ethylamine (up to 10 mumol/l) and dimaprit (up to 1 mumol/l) failed to affect the serotonin uptake. The concentration-dependent inhibitory effects of higher concentrations of 2-(2-thiazolyl)ethylamine and dimaprit (up to 1 mmol/l) were not diminished by the H1 receptor antagonist dimetindene and the H2 receptor antagonist ranitidine (1 and 100 mumol/l each), respectively. Histamine, 2-(2-thiazolyl)ethylamine, dimaprit and R-(-)-alpha-methylhistamine (up to 10 mumol/l) did not change the serotonin release from rat blood platelets. Our results demonstrate that histamine and histamine H1, H2 and H3 receptor agonists do not affect in a specific manner the serotonin uptake and release in rat blood platelets.

  5. A Study on the radiation effects for the function and structure of rabbit blood platelets in various dose rates

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, Kohichi (Nippon Dental Univ., Tokyo (Japan))

    1991-12-01

    Mature peripheral platelets in rabbits were irradiated with a total 10 Gy of {sup 60}Co-{gamma} rays at the average dose rates of 0.2, 0.5, 1.0, 1.5 and 1.7 Gy/min. The effects was evaluated from the functional aspect by determining the ability of platelets to aggregate and replease, and the metabolic aspect by examining the kinetics of prostaglandin in platelets. In addition, platelet structure was compared using an electron microscope. The ability of platelets to aggregate and release was accelerated in all irradiated groups, compared with a non-irradiated group, especially in groups with average dose rates of 0.5 Gy/min and 1.0 Gy/min. The amount of MDA, a final product of prostaglandin in platelets, increased in all irradiated groups in comparison with the non-irradiated group, especially in the 0.5 Gy/min, 1.0 Gy/min and 1.5 Gy/min groups. Observation with a scanning electron microscope revealed a clear rock-like appearance of the surface of aggregates of platelets and a larger number of pseudopodia with longer projections in the 1.0 Gy/min group than in the non-irradiated group. Moreover, the surfaces of the aggregates in the 1.7 Gy/min group, but the adhension between psudopodia of the platelet aggregates was weaker than that of 1.0 Gy/min group. In observation with a transmission electron microscope, dense bodies that released their contents were noticed in platelet aggregates, and a stenopeic appearance between psudopodia and between platelets, and density aggregated platelets were observed in the 1.0 Gy/min irradiated group. Vacuolation of granules in platelets was more marked in aggregates of 1.7 Gy/min group than in that of the non-irradiated group, and large numbers of platelets with uneven surfaces were observed. Therefore, the effects of dose rates were found to be closely related to changes in structures, as well as to the inner function of platelets. (author).

  6. What Happens to Donated Blood?

    Science.gov (United States)

    ... week. Learn About Blood Blood Facts and Statistics Blood Components Whole Blood and Red Blood Cells Platelets Plasma ... About Blood Blood Facts and Statistics Blood Types Blood Components What Happens to Donated Blood Blood and Diversity ...

  7. Function, expression and localization of annexin A7 in platelets and red blood cells: Insights derived from an annexin A7 mutant mouse

    Directory of Open Access Journals (Sweden)

    Zamparelli Carlotta

    2003-08-01

    Full Text Available Abstract Background Annexin A7 is a Ca2+- and phospholipid-binding protein expressed as a 47 and 51 kDa isoform, which is thought to be involved in membrane fusion processes. Recently the 47 kDa isoform has been identified in erythrocytes where it was proposed to be a key component in the process of the Ca2+-dependent vesicle release, a process with which red blood cells might protect themselves against an attack by for example complement components. Results The role of annexin A7 in red blood cells was addressed in erythrocytes from anxA7-/- mice. Interestingly, the Ca2+-mediated vesiculation process was not impaired. Also, the membrane organization appeared not to be disturbed as assessed using gradient fractionation studies. Instead, lack of annexin A7 led to an altered cell shape and increased osmotic resistance of red blood cells. Annexin A7 was also identified in platelets. In these cells its loss led to a slightly slower aggregation velocity which seems to be compensated by an increased number of platelets. The results appear to rule out an important role of annexin A7 in membrane fusion processes occurring in red blood cells. Instead the protein might be involved in the organization of the membrane cytoskeleton. Red blood cells may represent an appropriate model to study the role of annexin A7 in cellular processes. Conclusion We have demonstrated the presence of both annexin A7 isoforms in red blood cells and the presence of the small isoform in platelets. In both cell types the loss of annexin A7 impairs cellular functions. The defects observed are however not compatible with a crucial role for annexin A7 in membrane fusion processes in these cell types.

  8. Functional groups grafted nonwoven fabrics for blood filtration-The effects of functional groups and wettability on the adhesion of leukocyte and platelet

    Energy Technology Data Exchange (ETDEWEB)

    Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Cao Ye [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China); Sun Kang, E-mail: ksun@sjtu.edu.cn [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Liu Jiaxin; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610081 (China)

    2011-01-15

    In this work, the effects of grafted functional groups and surface wettability on the adhesion of leukocyte and platelet were investigated by the method of blood filtration. The filter materials, poly(butylene terephthalate) nonwoven fabrics bearing different functional groups including hydroxyl (OH), carboxyl (COOH), sulfonic acid group (SO{sub 3}H) and zwitterionic sulfobetaine group ({sup +}N((CH{sub 3}){sub 2})(CH{sub 2}){sub 3}SO{sub 3}{sup Circled-Minus }) with controllable wettability were prepared by UV radiation grafting vinyl monomers with these functional groups. Our results emphasized that both surface functional groups and surface wettability had significant effects on the adhesion of leukocyte and platelet. In the case of filter materials with the same wettability, leukocytes adhering to filter materials decreased in the order: the surface bearing OH only > the surface bearing both OH and COOH > the surface bearing sulfobetaine group > the surface bearing SO{sub 3}H, while platelets adhering to filter materials decreased as the following order: the surface bearing SO{sub 3}H > the surface bearing both OH and COOH > the surface bearing OH only > the surface bearing sulfobetaine group. As the wettability of filter materials increased, both leukocyte and platelet adhesion to filter materials declined, except that leukocyte adhesion to the surface bearing OH only remained unchanged.

  9. Effect of erythrocytes and prostacyclin production in the effect of fructose and sorbitol on platelet activation in human whole blood in vitro.

    Science.gov (United States)

    De la Cruz, J P; Maximo, M A; Blanco, E; Moreno, A; Sánchez de la Cuesta, F

    1997-06-15

    We analyzed the in vitro effects of sorbitol and fructose on platelet function. Sorbitol and fructose increased platelet aggregation induced with adenosine diphosphate (ADP) or collagen in whole blood, but had no effect in platelet-rich plasma. The concentration that increased basal aggregation by 50% with ADP as the inducer was 12.89 +/- 1.55 mmol/L for fructose, and 18.99 +/- 2.01 mmol/L for sorbitol. When collagen was the inducer, these concentrations were 15.02 +/- 0.98 mmol/L for fructose, and 12.94 +/- 1.57 mmol/L for sorbitol. Both sugars increased, in a concentration-dependent way, the proaggregatory effect of erythrocytes, and erythrocyte uptake of adenosine. Time to uptake of 50% adenosine was 2.1 +/- 0.3 min in control samples, 0.14 +/- 0.01 min in the presence of fructose, and 0.23 +/- 0.03 min with sorbitol. Both sugars reduced vascular prostacyclin synthesis, with 50% inhibitory concentrations of 26.48 +/- 1.97 mmol/L for fructose, and 39.53 +/- 2.81 mmol/L for sorbitol. Both sugars also increased arterial lipid peroxidation by 30% (sorbitol) and 23% (fructose). We conclude that these two sugars enhance platelet function and disrupt the thromboxane/prostacyclin ratio.

  10. Evaluation of coagulation factors and platelet function from an off-line modified ultrafiltration technique for post-cardiopulmonary bypass circuit blood recovery.

    Science.gov (United States)

    Beckmann, S; Lynn, P; Miller, S; Harris, R; DiMarco, R F; Ross, J E

    2013-05-01

    Modified ultrafiltration (MUF) is a technique that hemoconcentrates residual CPB circuit blood and the patient at the same time. Hemoconcentration and MUF are Class 1-A recommendations in the anesthesia and surgical blood conservation guidelines. This study evaluated the off-line MUF process of the Hemobag (HB, Global Blood Resources, Somers, CT, USA) to quantitate coagulation factor levels, platelet (PLT) count and function in one facility and cellular growth factor concentrations of the final product that were transfused to the patient in another facility In two cardiac surgery facilities, after decannulation, the extracorporeal circuit (ECC) blood from 22 patients undergoing cardiac surgery was processed with the HB device. In eleven patients from the first facility by the study design, blood samples for coagulation factor levels and PLT aggregation were drawn from the reservoir of the MUF device pre- and post-processing. The samples (n = 11) were sent to a reference laboratory where testing for prothrombin time (PT), international normalized ratio (INR), activated partial thromboplastin time (aPTT), reptilase time, fibrinogen, clotting factors II, V, VII, VIII, IX, X, ADAMTS-13, protein C, protein S, antithrombin III, von Willebrand Factor (vWF), and platelet (PLT) aggregation were performed. A portion of the final concentrated HB blood samples (n = 5-10) from the second facility by design were evaluated for transforming and platelet-derived cellular growth factor concentrations. On average, approximately 800 - 2000 mls of whole blood were removed from the ECC post-CPB for processing in the HB device. After processing, there was, on the average, approximately 300 - 950 mls of concentrated whole blood salvaged for reinfusion. The PT and INR were significantly lower in the post-processing product compared to the pre-processing samples while the aPTT times were not significantly different. All coagulation factors and natural anti-coagulants were significantly

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

    Science.gov (United States)

    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

  12. Imaging the interaction between dengue 2 virus and human blood platelets using atomic force and electron microscopy.

    Science.gov (United States)

    Ghosh, Kanjaksha; Gangodkar, Shobha; Jain, Preksha; Shetty, Shrimati; Ramjee, Sandhya; Poddar, Pankaj; Basu, Atanu

    2008-06-01

    Thrombocytopenia is frequently associated with dengue virus infection. Host factors such as anti-platelet immunopathogenic processes have been implicated in the origin of dengue-associated thrombocytopenia but the role of dengue virus in directly interacting with platelets and altering their hemostatic property remains incompletely understood. In the present study, we examined the effect of dengue 2 virus on the morphology and physiological activation profile of normal human platelets using atomic force microscopy, electron microscopy and flowcytometry. Platelets obtained from healthy donors were exposed to a cell culture-adapted 10(4) LD(50) dengue 2 virus isolate in vitro and the subsequent effect on morphology and activation biology studied. Our results show that dengue 2 virus exposure at doses comparable to natural viremic states in human infections can activate platelets with an increase in P-selectin expression and fibrinogen-binding property. Atomic force, scanning and transmission electron microscopy also showed typical activation-related morphological changes such as altered platelet membrane architecture, degranulation, presence of filopodia and dilatation of the open canalicular system in the dengue 2 virus-exposed platelets but not in the controls. Importantly, Japanese encephalitis virus exposure at the same dose did not activate platelets or show any morphological changes. Our findings suggest that dengue 2 virus may directly interact with and activate platelets - an event that might be important in the origin of dengue-associated thrombocytopenia. Detailed molecular characterization of this effect might provide key knowledge toward better prophylaxis of the hemostatic complications of dengue disease.

  13. Effect of Venous Blood and Peripheral Blood on Platelet Count%静脉采血和末梢采血对血小板计数的影响

    Institute of Scientific and Technical Information of China (English)

    薛可

    2015-01-01

    Objective Impact analysis of peripheral venous blood and blood platelet count. Methods 30 patients taking the hospital from October 2012 to October 2014 to detect blood of all patients receiving peripheral blood and blood collection. At the same time the use of automated blood cell analyzer for two kinds of venous blood and peripheral blood collection methods for scientiifc testing. Results The number of blood platelets would cause different types of methods of direct influence, t=6.57, significant statistical significance (P<0.05). Conclusion Thrombocytopenia, blood velocity, counting the number of cells and other factors are the main factors that affect platelet count results. Venous blood and peripheral blood platelet count also has a certain impact.%目的:研究分析静脉采血和末梢采血对血小板计数的影响。方法选取本院2012年10月~2014年10月检测血常规的30例患者,全部患者接受末梢血以及静脉血的采集。与此同时使用血细胞自动分析仪对静脉采血和末梢采血两种采集方法进行科学的检测。结果不同类型的采血方法会对血小板数目造成直接性的影响,t=6.57,具有显著性统计学意义(P<0.05)。结论血小板减少症、采血速度、计数格数等因素是影响小板计数结果的主要因素。静脉采血和末梢采血对血小板计数也具有一定的影响。

  14. Haemostasis monitored in stored red blood cells, plasma and platelet concentrates in the proportion of 4 :  4 :  1 diluted with crystalloids and colloids.

    Science.gov (United States)

    Ågren, Anna; Edgren, Gustaf; Ambrosio, Daniela; Gryfelt, Gunilla; Östlund, Anders; Wikman, Agneta

    2016-04-01

    The aim of this in-vitro study was to evaluate haemostasis analysed with thromboelastometry and blood gas and blood count variables, in stored blood components and the effects after dilution with Ringer[Combining Acute Accent]s acetate, albumin and hydroxyethyl starch (HES). Aliquots from stored red blood cells, plasma and platelet concentrates were mixed in the proportion of 4 : 4 : 1 and analysed with rotational thromboelastometry (ROTEM), blood count [haemoglobin (Hb), haematocrit, platelet count] and blood gas (pH, calcium, sodium, potassium, glucose levels). The blood mix was thereafter diluted 20 and 33% with Ringer's acetate, albumin or HES. The stored blood component mix in a ratio of 4 : 4 : 1 had a low pH (7.11 ± 0.03, mean ± standard deviation), nonmeasurable calcium level, and high concentrations of sodium, potassium and glucose but ROTEM curves within normal range after recalcification. With Ringer's acetate dilution, the ROTEM variables changed almost linearly with increasing dilution volume. When albumin was used in the 33% dilution, the clot firmness of the fibrin clot (FibTEM) was further reduced, and with HES dilution, there was a pronounced impairment. The stored blood mix had a low pH and calcium level, both of which might have a significant influence on the coagulation process but normal ROTEM curves after recalcification. Dilution with Ringer's acetate and albumin resulted in moderate deterioration, while dilution with HES showed severely impaired haemostasis.

  15. Blood storage time on platelet detection effect%全血放置时间对血小板检测的影响

    Institute of Scientific and Technical Information of China (English)

    李松涛

    2012-01-01

    目的:探讨全血放置不同时间对血细胞分析仪上检测血小板的影响.方法:使用EDTA-K2抗凝血放置不同时间检测血小板并用瑞氏染色不同时间抗凝血涂片观察血小板分布情况,与手工法检测结果进行t检验.结果:全血放置0分钟、5分钟、6小时时机测与手工法结果血小板< 90×109/L时t值<0.01,有极显著性差异.血小板>90×109/L时t值<0.05,有显著性差异.血小板检测结果均减少在10min、30min、90min、120min时机测与手工法结果均无显著性差异.结论:在使用血细胞分析仪检测时,EDTA-K2抗凝血在10min至120min之间检测,结果真实可靠.%Objective To investigate the whole blood placed at different time on blood cell analyzer on the detection of platelet effect. Method Use EDTA - K2 anticoagulant placed at different time for detection of platelet with Wright's staining at different time anticoagulant smears observed platelet distribution, and manual detection results were analyzed by t test. Results The whole blood placed 0 minutes, 5 minutes, 6 hour machine and manual method measurement results of platelet 90 × 109 /L T < 0.05, there was significant difference. Platelet detection, results were reduced in 10 minutes, 30 minutes, 90 minutes, 120 minutes of time measurement and the manual method the results showed no significant differences. Conclusions In the use of blood cell analyzer, EDTA, K2 anticoagulant in 10 to 120 minutes between detection, reliable results.

  16. Influence factors of handmade concentratd blood platelets%手工制备浓缩血小板影响因素探讨

    Institute of Scientific and Technical Information of China (English)

    唐泽萍

    2012-01-01

    Objective To analyze the influence factors of handmade concentrated blood platelets and to improve the quality and the clinical injection effect of handmade concentrated platelets. Methods The blood donors not taken aspirin before donating blood in 72 hours were randomly enrolled in this study. The peripheral blood platelets counts were normal; blood were collected smoothly; then platelets concentrate were reserved by same centrifuging method (platelet-rich plasma method). The influence of centrifugal conditions and whole blood specifications on collecting platelets were analyzed. Results The 400ml whole blood under 2000rp, 2100rpm, 2200rpm, centrifugalize 5min platelets (unit: 109/L) 84. 0±14、90. 5±10. 5, 3. 89±0. 48, and 6min platelets (unit: 10°/L 86. 3±11. 5, 121. 5±17. 7, 85.0±16. 5. There-suits under 2100rpm and centrifugalized 6min have significant difference, compared with other groups; There is no obvious difference between other groups (P>0. 5). The difference between the platelets (1. 46±0. 28, 3. 53±0. 66, 4. 86± 0.71) prepared with 400, 300, 200ml whole blood respectively was not obvious, however the difference is significant compared 200ml with 400, 30 0ml (P<0. 01). Conclusion Under the same separation method, but different centrifuga-tion conditions, type of blood, the platelet concentrate prepared with 400 ml of whole blood under the condition that the rotating speed is 2100 rpm, the centrifuging time is 6 min, and the centrifuging temperature is 22 degrees centigrade has the highest content and the best collecting effect.%目的 探讨手工制备浓缩血小板的影响因素,提高手工浓缩血小板的质量和临床输注效果.方法 随机选择献血者且献血前72小时内未服用过阿斯匹林类药物,外周血小板计数正常,采血顺畅,采用相同的分离方法(富含血小板血浆法)手工制备浓缩血小板,观察不同规格的全血,或不同的离心条件,对收集血小板的影响.结果 400ml

  17. 手工制备浓缩血小板影响因素的探讨%Influence factors of handmade blood platelets concentrate

    Institute of Scientific and Technical Information of China (English)

    唐泽萍

    2012-01-01

    目的 探讨手工制备浓缩血小板的影响因素,提高手工浓缩血小板的质量和临床输注效果.方法 随机选择献血前72小时内未服用过阿斯匹林类药物的献血者,外周血小板计数正常,采血顺畅,采用相同的分离方法(富含血小板血浆法)制备手工浓缩血小板,观察不同规格的全血,或不同的离心条件对收集血小板的影响.结果 400ml全血分别在2000、2100和2200 rpm,离心5 min血小板为(84.0±14)、(90.5±10.5)、(3.89±0.48) 109/L,离心6min血小板为(86.3±11.5)、(121.5±17.7)、(85.0±16.5)109/L,经统计学处理2100 rpm离心6 min结果与其它组比较差异显著(P<0.01);其它各组相互比较差异不显著(P>0.5).全血量分别为400、300、200ml时分离出的血小板为(1.46±0.28)、(3.53±0.66)、(4.86±0.71)109/L,400、300ml间比较差异不显著(P>0.5),200ml与400、300ml间比较差异显著(P<0.01).结论 采用相同的分离法,不同的离心条件、血液规格收集血小扳均有影响,400ml的全血,转速为2 100rpm/min,6min,22℃离心制备的浓缩血小板含量最高,收集效果最好.%Objective To analyze the influence factors of handmade blood platelets concentrate and improve the quality and the clinical injection effect of handmade platelets concentrate. Methods The blood donors who hadn't taken aspirin medicine before donating blood in 72 hours were randomly enrolled in this study: peripheral blood platelets counts were normal; blood were collected smoothly; then platelets concentrate were reserved by same centrifuging method ( platelet-rich plasma method) to discuss the influence of centrifugal conditions or whole blood specifications on collecting platelets. Results The 400ml whole blood under 2000rpp, 2100rpm, 2200rpm, centrifugalize 5min platelets (unit:109/ L) 84.0±14,90.5±10.5,3.89±0.48, and 6min platelets (unit: 109/L) 86. 3± 11. 5、121. 5± 17. 7、85. 0± 16. 5. The results under 2100rpm and centrifugalized 6min

  18. Platelet function in dogs

    DEFF Research Database (Denmark)

    Nielsen, Line A.; Zois, Nora Elisabeth; Pedersen, Henrik D.

    2007-01-01

    Background: Clinical studies investigating platelet function in dogs have had conflicting results that may be caused by normal physiologic variation in platelet response to agonists. Objectives: The objective of this study was to investigate platelet function in clinically healthy dogs of 4...... different breeds by whole-blood aggregometry and with a point-of-care platelet function analyzer (PFA-100), and to evaluate the effect of acetylsalicylic acid (ASA) administration on the results from both methods. Methods: Forty-five clinically healthy dogs (12 Cavalier King Charles Spaniels [CKCS], 12...... applied. However, the importance of these breed differences remains to be investigated. The PFA-100 method with Col + Epi as agonists, and ADP-induced platelet aggregation appear to be sensitive to ASA in dogs....

  19. Effect of Eggplant Stalk on Platelets, Red Blood Cells and White Blood Cells in Mice%茄杆对小鼠血小板红细胞白细胞的作用

    Institute of Scientific and Technical Information of China (English)

    蒙根; 李峰; 杜风珍; 张翠荣

    2001-01-01

    目的:用免疫性血小板减少小鼠模型观察了茄杆对小鼠血小板、红细胞和白细胞的影响。方法:采用昆明种小鼠分组给药。结果:茄杆煎剂能明显增加小鼠的血小板,但对其红细胞和白细胞没有明显影响。结论:该药具有增加血小板的作用。%In this paper, the effect of eggplant stalk on platelets, redblood cells and white blood cells in mice suffering from immune thrombocytopenia was observed. The result showed that the decoction of eggplant stalk could obviously increase the number of platelet of mice, but it had no distinct influence on the white blood cells and red blood cells of mice. It suggested that the drug could raise the number of platelet.

  20. A randomized trial of washed red blood cell and platelet transfusions in adult acute leukemia [ISRCTN76536440

    Directory of Open Access Journals (Sweden)

    Rowe Jacob M

    2004-12-01

    Full Text Available Abstract Background Platelet transfusion is universally employed in acute leukemia. Platelet concentrate supernatants contain high concentrations of biologic mediators that might impair immunity. We investigated whether washed platelet and red cell transfusions could improve clinical outcomes in adult patients with acute leukemia. Methods A pilot randomized trial of washed, leukoreduced ABO identical transfusions versus leukoreduced ABO identical transfusions was conducted in 43 adult patients with acute myeloid or lymphoid leukemia during 1991–94. Primary endpoints to be evaluated were platelet transfusion refractoriness, infectious and bleeding complications and overall survival. Results There were no significant differences in infectious or major bleeding complications and only one patient required HLA matched platelet transfusions. Minor bleeding was more frequent in the washed, leukoreduced arm of the study. Confirmed transfusion reactions were more frequent in the leukoreduced arm of the study. Overall survival was superior in the washed arm of the study (40% versus 22% at 5 years, but this difference was not statistically significant (p = 0.36. A planned subset analysis of those ≤50 years of age found that those in the washed, leukoreduced arm (n = 12 had a 75% survival at five years compared with 30% in the leukoreduced arm (n = 10 (p = 0.037 Conclusion This study provides the first evidence concerning the safety and efficacy of washed platelets, and also raises the possibility of improved survival. We speculate that transfusion of stored red cell and platelet supernatant may compromise treatment, particularly in younger patients with curable disease. Larger trials will be needed to assess this hypothesis.

  1. Investigation of platelet function and platelet disorders using flow cytometry.

    Science.gov (United States)

    Rubak, Peter; Nissen, Peter H; Kristensen, Steen D; Hvas, Anne-Mette

    2016-01-01

    Patients with thrombocytopenia or platelet disorders are at risk of severe bleeding. We report the development and validation of flow cytometry assays to diagnose platelet disorders and to assess platelet function independently of platelet count. The assays were developed to measure glycoprotein levels (panel 1) and platelet function (panel 2) in sodium citrated blood. Twenty healthy volunteers and five patients diagnosed with different platelet disorders were included. Glycoprotein expression levels of the receptors Ia, Ib, IIb, IIIa and IX were measured and normalised with forward scatter (FS) as a measurement of platelet size. Platelet function was assessed by CD63, P-selectin and bound fibrinogen in response to arachidonic acid, adenosine diphosphate (ADP), collagen-related peptide, ristocetin and thrombin receptor-activation peptide-6. All patients except one with suspected δ-granule defect showed aberrant levels of glycoproteins in panel 1. Glanzmann's thrombasthenia and genetically verified Bernard-Soulier syndrome could be diagnosed using panel 1. All patients showed reduced platelet function according to at least one agonist. Using panel 2 it was possible to diagnose Bernard-Soulier syndrome, δ-granule defect and GPVI disorder. By combining the two assays, we were able to diagnose different platelet disorders and investigate platelet function independent of platelet count.

  2. Reproducibility of Manual Platelet Estimation Following Automated Low Platelet Counts

    Directory of Open Access Journals (Sweden)

    Zainab S Al-Hosni

    2016-11-01

    Full Text Available Objectives: Manual platelet estimation is one of the methods used when automated platelet estimates are very low. However, the reproducibility of manual platelet estimation has not been adequately studied. We sought to assess the reproducibility of manual platelet estimation following automated low platelet counts and to evaluate the impact of the level of experience of the person counting on the reproducibility of manual platelet estimates. Methods: In this cross-sectional study, peripheral blood films of patients with platelet counts less than 100 × 109/L were retrieved and given to four raters to perform manual platelet estimation independently using a predefined method (average of platelet counts in 10 fields using 100× objective multiplied by 20. Data were analyzed using intraclass correlation coefficient (ICC as a method of reproducibility assessment. Results: The ICC across the four raters was 0.840, indicating excellent agreement. The median difference of the two most experienced raters was 0 (range: -64 to 78. The level of platelet estimate by the least-experienced rater predicted the disagreement (p = 0.037. When assessing the difference between pairs of raters, there was no significant difference in the ICC (p = 0.420. Conclusions: The agreement between different raters using manual platelet estimation was excellent. Further confirmation is necessary, with a prospective study using a gold standard method of platelet counts.

  3. Gasotransmitters and platelets.

    Science.gov (United States)

    Truss, Nicola J; Warner, Timothy D

    2011-11-01

    Platelets are essential to prevent blood loss and promote wound healing. Their activation comprises of several complex steps which are regulated by a range of mediators. Over the last few decades there has been intense interest in a group of gaseous mediators known as gasotransmitters; currently comprising nitric oxide (NO), carbon monoxide (CO) and hydrogen sulphide (H(2)S). Here we consider the action of gasotransmitters on platelet activity. NO is a well established platelet inhibitor which mediates its effects predominantly through activation of soluble guanylyl cyclase leading to a decrease in intraplatelet calcium. More recently CO has been identified as a gasotransmitter with inhibitory actions on platelets; CO acts through the same mechanism as NO but is less potent. The in vivo and platelet functions of the most recently identified gasotransmitter, H(2)S, are still the subject of investigations, but they appear generally inhibitory. Whilst there is evidence for the individual action of these mediators, it is also likely that combinations of these mediators are more relevant regulators of platelets. Furthermore, current evidence suggests that these mediators in combination alter the production of each other, and so modify the circulating levels of gasotransmitters. The use of gasotransmitters as therapeutic agents is also being explored for a range of indications. In conclusion, the importance of NO in the regulation of vascular tone and platelet activity has long been understood. Other gasotransmitters are now establishing themselves as mediators of vascular tone, and recent evidence suggests that these other gasotransmitters may also modulate platelet function.

  4. Effects of the platelet-activating factor receptor antagonist BN 52021 on hematologic variables and blood loss during and after cardiopulmonary bypass.

    Science.gov (United States)

    Nathan, N; Mercury, P; Denizot, Y; Cornu, E; Laskar, M; Arnoux, B; Feiss, P

    1994-08-01

    Cardiopulmonary bypass (CPB)-induced thrombocytopenia and leukopenia is augmented after heparin reversal of protamine. Platelet-activating factor (PAF) might be implicated in these disorders. To evaluate the effects of PAF on the hematologic disorders and blood loss during and after CPB, patients were pretreated with BN 52021, a PAF receptor antagonist, or a placebo. BN 52021 (120 mg) (n = 13) or placebo (n = 15) were infused intravenously before vascular cannulation and before cross-clamp release. Platelet and leukocyte counts were assessed in venous blood before and after the first dose of BN 52021 or placebo, 2 min after the beginning of CPB (at the entry of the oxygenator), at the end of CPB, 1, 15, and 30 min after protamine infusion, and 6 and 24 h after CPB. The decrease in platelet and leukocyte counts were the same between groups during and after CPB and after protamine infusion. Bleeding times were not modified by the pretreatment of patients with BN 52021. During surgery, blood loss reached 1660 +/- 297 mL in the BN 52021 group and 1599 +/- 283 mL in the placebo group (P > 0.05). Forty-eight hours postoperatively, the chest tube outputs were not different between groups (1460 +/- 418 mL vs 1640 +/- 362 mL in the BN 52021 and placebo groups, respectively). This study shows that BN 52021 infusion did not change the hematologic variables studied. Moreover, a PAF antagonist pretreatment did not protect the patients against CPB- or protamine-induced hematologic changes.

  5. Disruption and activation of blood platelets in contact with an antimicrobial composite coating consisting of a pyridinium polymer and AgBr nanoparticles.

    Science.gov (United States)

    Stevens, Kris N; Knetsch, Menno L; Sen, Ayusman; Sambhy, Varun; Koole, Leo H

    2009-09-01

    Composite materials made up from a pyridinium polymer matrix and silver bromide nanoparticles embedded therein feature excellent antimicrobial properties. Most probably, the antimicrobial activity is related to the membrane-disrupting effect of both the polymer matrix and Ag(+) ions; both may work synergistically. One of the most important applications of antimicrobial materials would be their use as surface coatings for percutaneous (skin-penetrating) catheters, such as central venous catheters (CVCs). These are commonly used in critical care, and serious complications due to bacterial infection occur frequently. This study aimed at examining the possible effects of a highly antimicrobial pyridinium polymer/AgBr composite on the blood coagulation system, i.e., (i) on the coagulation cascade, leading to the formation of thrombin and a fibrin cross-linked network, and (ii) on blood platelets. Evidently, pyridinium/AgBr composites could not qualify as coatings for CVCs if they trigger blood coagulation. Using a highly antimicrobial composite of poly(4-vinylpyridine)-co-poly(4-vinyl-N-hexylpyridinium bromide) (NPVP) and AgBr nanoparticles as a thin adherent surface coating on Tygon elastomer tubes, it was found that contacting blood platelets rapidly acquire a highly activated state, after which they become substantially disrupted. This implies that NPVP/AgBr is by no means blood-compatible. This disqualifies the material for use as a CVC coating. This information, combined with earlier findings on the hemolytic effects (i.e., disruption of contacting red blood cells) of similar materials, implies that this class of antimicrobial materials affects not only bacteria but also mammalian cells. This would render them more useful outside the biomedical field.

  6. Adhesion, activation, and aggregation of blood platelets and biofilm formation on the surfaces of titanium alloys Ti6Al4V and Ti6Al7Nb.

    Science.gov (United States)

    Walkowiak-Przybyło, M; Klimek, L; Okrój, W; Jakubowski, W; Chwiłka, M; Czajka, A; Walkowiak, B

    2012-03-01

    Titanium alloys are still on the top list of fundamental materials intended for dental, orthopedics, neurological, and cardiovascular implantations. Recently, a special attention has been paid to vanadium-free titanium alloy, Ti6Al7Nb, that seems to represent higher biocompatibility than traditional Ti6Al4V alloy. Surprisingly, these data are not thoroughly elaborated in the literature; particularly there is a lack of comparative experiments conducted simultaneously and at the same conditions. Our study fills these shortcomings in the field of blood contact and microbiological colonization. To observe platelets adhesion and biofilm formation on the surfaces of compared titanium alloys, fluorescence microscope Olympus GX71 and scanning electron microscope HITACHI S-3000N were used. Additionally, flow cytometry analysis of platelets aggregation and activation in the whole blood after contact with sample surface, as an essential tool for biomaterial thrombocompatibility assessment, was proposed. As a result of our study it was demonstrated that polished surfaces of Ti6Al7Nb and Ti6Al4V alloys after contact with whole citrated blood and E. coli bacterial cells exhibit a considerable difference. Overall, it was established that Ti6Al4V has distinct tendency to higher thrombogenicity, more excessive bacterial biofilm formation and notable cytotoxic properties in comparison to Ti6Al7Nb. However, we suggest these studies should be extended for other types of cells and biological objects.

  7. Extracting Biological Meaning From Global Proteomic Data on Circulating-Blood Platelets: Effects of Diabetes and Storage Time

    Energy Technology Data Exchange (ETDEWEB)

    Miller, John H.; Suleiman, Atef; Daly, Don S.; Springer, David L.; Spinelli, Sherry L.; Blumberg, Neil; Phipps, Richard P.

    2008-11-25

    Transfusion of platelets into patients suffering from trauma and a variety of disease is a common medical practice that involves millions of units per year. Partial activation of platelets can result in the release of bioactive proteins and lipid mediators that increase the risk of adverse post-transfusion effects. Type-2 diabetes and storage are two factors known to cause partial activation of platelets. A global proteomic study was undertaken to investigate these effects. In this paper we discuss the methods used to interpret these data in terms of biological processes affected by diabetes and storage. The main emphasis is on the processing of proteomic data for gene ontology enrichment analysis by techniques originally designed for microarray data.

  8. Blood Platelet Disorder and Laboratory Examination%血小板疾病及实验室检查

    Institute of Scientific and Technical Information of China (English)

    台虹

    2006-01-01

    血小板是一个多功能的细胞,它的主要生理功能是参与止血与血栓的形成。血小板疾病依据血小板质和量异常被分为血小板功能异常性疾病(Platelet Function Disorder)和血小板数量异常性疾病(Platelet Quantity Disorder)。血小板数量异常包括血小板减少症(Thrombocytopenia)和血小板增多症(Throbocythemia)。

  9. Effects of bemiparin and heparin on blood pressure, renal and liver function tests and platelet indices of salt-loaded uninephrectomized rats

    Directory of Open Access Journals (Sweden)

    K. Dizaye

    2011-01-01

    Full Text Available Low-molecular-weight Heparins (LMWHs are being preferred to unfractionated Heparin (UFH because of their superior convenience and comparable or slightly better toxicity profile. This study was designed to investigate and compare the effects of LMWH (Bemiparin and Heparin on hemodynamic parameters, liver and renal function tests and platelet indices of salt-loaded uninephrectomized hypertensive rats. The experimental rats divided into two groups. The first group included 18 hypertensive rats. Hypertension induced by unilateral nephrectomy and high NaCl loading with 4% NaCl in diet for 4 weeks. The rat models were subdivided into three groups, each subgroup consists of six rats. The first subgroup served as a positive control. The second subgroup received a daily intraperitoneal (I.P injection (250 unit/kg of Bemiparin for thirty days. The third sub group received daily I.P injection (250 unit/kg of Heparin for thirty days. The second group included six rats underwent sham operated surgery and served as a control group. Blood pressure was recorded in conscious rats by the tail-cuff plethmography method. At the end of the experiments, blood samples were collected from the rats for determination of serum creatinine, blood urea nitrogen, serum total bilirubin, serum sodium, potassium, calcium, aspartate aminotransferase (AST, alanine aminotransferase (ALT, alkaline phosphatase (ALP concentrations and platelet indices. Compared to sham control rats, Systolic blood pressure in uninephrectomized loaded with a high salt was significantly reduced by administration of both Bemiparin and Heparin. Serum K+ and Na+ levels of hypertensive rats were significantly increased. Bemiparin significantly lowered serum K+ and Na+ levels of uninephrectomized rats, while Heparin did not change serum K+ and Na+ levels. The rise in both blood urea and serum creatinine of salt-loaded uninephrectomized hypertensive rats were significantly (P<0.05 reduced by Bemiparin and

  10. 配型血小板输注在血液病患者中的应用%The Application of Cross-matched Platelet in Patients with Blood Diseases

    Institute of Scientific and Technical Information of China (English)

    叶静梅; 许志晟; 李翊泉; 李碧珊; 谭获

    2015-01-01

    目的:通过对比血小板配型前后血小板的输注效果,评估配型血小板在血液病患者中的疗效。方法以临床出血症状改善的情况、血小板计数增高指数(CCI)及血小板恢复百分率(PPR)为标准,对比配型前后血小板的输注效果。另外以临床输注血小板的次数分组,比较不同输注次数的患者出现血小板输注无效的差异。结果与配型前相比,配型血小板大大提高输注疗效(P <0.01),临床上输注5次血小板以上的患者比5次以下者出现血小板输注无效(PTR)的机率大大提高(P <0.01)。结论 PTR 的出现与血小板输注次数有关。在出现 PTR 的血液病患者中使用配型血小板输注,可提高输注效果。%Objective To evaluate the clinical significance of platelets cross-matched on platelet trans-fusion refractoriness of blood diseases by comparing the efficiency of transfusion before and after platelets cross-matched. Methods Regarding the improvement of haemorrhage symptom,corrected count increment (CCI),percent platelet recovery(PPR)as the standard,the efficiency of transfusion of before and after plate-lets cross-matched were compared. And comparing the difference of platelet transfusion refractoriness(PTR)by regarding on different times of platelet transfusion. Results Compare with before cross- matched,after cross-matched platelet transfusion was greatly improve curative effect( P < 0. 01). And the more times of platelet transfusion(≥5),the more probability of PTR was appearing(P < 0. 01). Conclusion PTR was related to the number of platelet transfusion. Cross- matched platelet transfusionis an effective method in those patients refractory to random platelet transfusions. It should advocate to use cross-matched platelet in blood diseases.

  11. Platelet Count

    Science.gov (United States)

    ... their spleen removed surgically Use of birth control pills (oral contraceptives) Some conditions may cause a temporary (transitory) increased ... increased platelet counts include estrogen and birth control pills (oral contraceptives). Mildly decreased platelet counts may be seen in ...

  12. Platelet mimicry

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Hunter, Alan Christy; Peer, Dan

    2016-01-01

    Here we critically examine whether coating of nanoparticles with platelet membranes can truly disguise them against recognition by elements of the innate immune system. We further assess whether the "cloaking technology" can sufficiently equip nanoparticles with platelet-mimicking functionalities...

  13. PREGNANCY WITH PLATELET FUNCTION DISORDER

    Directory of Open Access Journals (Sweden)

    Sheila K

    2014-01-01

    Full Text Available latelets play a vital role in haemostasis . Antenatal patients with platelet function disorders should be managed in tertiary care centres that are well equipped to tackle any obstetric haemorrhage that can ensue during labour and delivery . Primi gravida was admitted for safe confinement . She had been evaluated earlier for complaints of multiple episodes of mucosal bleeding . On evaluation she had nor mal platelet counts and coagulation factor assay was normal . Platelet aggregometry revealed mild disorder of platelet aggregation . She was planned for induction of labour after arranging enough blood and blood products . She got into active labour and was p ut on syntocinon augmentation . She had emergency Caesarean section for foetal distress . Oxytocics were given proactively . Intraoperatively platelet transfusions and tranexamic acid infusion were given . Complete haemostasis was achieved . She had an uneventf ul postoperative period . Patients with functional platelet disorders can be successfully managed with local application of antifibrinolytic agents like tranexamic acid , in case of minor bleeds . Platelet transfusions are very effective in tackling major ble eds , especially during surgeries and for obstetric indications . If a patient has the history of clinically significant bleeding suggestive of platelet dysfunction , appropriate platelet function tests should be obtained so that the risk of bleeding can be adequately assessed and therapy chosen more rationally . . In obstetric practice the response of such patients to platelet transfusions has been excellent

  14. Human platelets produced in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice upon transplantation of human cord blood CD34(+) cells are functionally active in an ex vivo flow model of thrombosis.

    Science.gov (United States)

    Salles, Isabelle I; Thijs, Tim; Brunaud, Christine; De Meyer, Simon F; Thys, Johan; Vanhoorelbeke, Karen; Deckmyn, Hans

    2009-12-01

    Xenotransplantation systems have been used with increasing success to better understand human hematopoiesis and thrombopoiesis. In this study, we demonstrate that production of human platelets in nonobese diabetic/severe combined immunodeficient mice after transplantation of unexpanded cord-blood CD34(+) cells was detected within 10 days after transplantation, with the number of circulating human platelets peaking at 2 weeks (up to 87 x 10(3)/microL). This rapid human platelet production was followed by a second wave of platelet formation 5 weeks after transplantation, with a population of 5% still detected after 8 weeks, attesting for long-term engraftment. Platelets issued from human hematopoietic stem cell progenitors are functional, as assessed by increased CD62P expression and PAC1 binding in response to collagen-related peptide and thrombin receptor-activating peptide activation and their ability to incorporate into thrombi formed on a collagen-coated surface in an ex vivo flow model of thrombosis. This interaction was abrogated by addition of inhibitory monoclonal antibodies against human glycoprotein Ibalpha (GPIbalpha) and GPIIb/IIIa. Thus, our mouse model with production of human platelets may be further explored to study the function of genetically modified platelets, but also to investigate the effect of stimulators or inhibitors of human thrombopoiesis in vivo.

  15. Off-target effect of the Epac agonist 8-pCPT-2'-O-Me-cAMP on P2Y12 receptors in blood platelets.

    Science.gov (United States)

    Herfindal, Lars; Nygaard, Gyrid; Kopperud, Reidun; Krakstad, Camilla; Døskeland, Stein Ove; Selheim, Frode

    2013-08-09

    The primary target of the cAMP analogue 8-pCPT-2'-O-Me-cAMP is exchange protein directly activated by cAMP (Epac). Here we tested potential off-target effects of the Epac activator on blood platelet activation signalling. We found that the Epac analogue 8-pCPT-2'-O-Me-cAMP inhibits agonist-induced-GPCR-stimulated, but not collagen-stimulated, P-selectin surface expression on Epac1 deficient platelets. In human platelets, 8-pCPT-2'-O-Me-cAMP inhibited P-selectin expression elicited by the PKC activator PMA. This effect was abolished in the presence of the extracellular ADP scavenger system CP/CPK. In silico modelling of 8-pCPT-2'O-Me-cAMP binding into the purinergic platelet receptor P2Y12 revealed that the analogue docks similar to the P2Y12 antagonist 2MeSAMP. The 8-pCPT-2'-O-Me-cAMP analogue per se, did not provoke Rap 1 (Rap 1-GTP) activation or phosphorylation on the vasodilator-stimulated phosphoprotein (VASP) at Ser-157. In addition, the protein kinase A (PKA) antagonists Rp-cAMPS and Rp-8-Br-cAMPS failed to block the inhibitory effect of 8-pCPT-2'-O-Me-cAMP on thrombin- and TRAP-induced Rap 1 activation, thus suggesting that PKA is not involved. We conclude that the 8-pCPT-2'-O-Me-cAMP analogue is able to inhibit agonist-induced-GPCR-stimulated P-selectin independent from Epac1; the off-target effect of the analogue appears to be mediated by antagonistic P2Y12 receptor binding. This has implications when using cAMP analogues on specialised system involving such receptors. We found, however that the Epac agonist 8-Br-2'-O-Me-cAMP did not affect platelet activation at similar concentrations.

  16. Physiopathology of blood platelets: a model system for studies of cell-to-cell interaction. Progress report, November 1, 1978-October 31, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, M G

    1979-01-01

    In this report, we will limit ourselves to the detailed description of four major sections of our research done during the past year: platelet interaction with tumor cells; studies of the interaction of platelets with macrophages; interaction of platelets with vessel walls; and further studies of cyclic nucleotides on stored platelets.

  17. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part II: platelet-related biologic features.

    Science.gov (United States)

    Dohan, David M; Choukroun, Joseph; Diss, Antoine; Dohan, Steve L; Dohan, Anthony J J; Mouhyi, Jaafar; Gogly, Bruno

    2006-03-01

    Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this second article, we investigate the platelet-associated features of this biomaterial. During PRF processing by centrifugation, platelets are activated and their massive degranulation implies a very significant cytokine release. Concentrated platelet-rich plasma platelet cytokines have already been quantified in many technologic configurations. To carry out a comparative study, we therefore undertook to quantify PDGF-BB, TGFbeta-1, and IGF-I within PPP (platelet-poor plasma) supernatant and PRF clot exudate serum. These initial analyses revealed that slow fibrin polymerization during PRF processing leads to the intrinsic incorporation of platelet cytokines and glycanic chains in the fibrin meshes. This result would imply that PRF, unlike the other platelet concentrates, would be able to progressively release cytokines during fibrin matrix remodeling; such a mechanism might explain the clinically observed healing properties of PRF.

  18. Dengue platelets meet Sir Arthur Conan Doyle.

    Science.gov (United States)

    Bray, Paul F

    2013-11-14

    In this issue of Blood, Hottz et al provide compelling evidence that dengue virus (DV) induces (1) platelet synthesis of interleukin-1b (IL-1b); (2) platelet-derived IL-1b–containing microvesicles (MVs) that increase vascular permeability; and (3) DV-triggered inflammasome activation in platelets.

  19. Molecular Basis Linking Platelet to Inflammation

    Institute of Scientific and Technical Information of China (English)

    马丽萍

    2010-01-01

    @@ Introduction Blood platelets not only play an important role in hemostasis and thrombosis,but increasing evidence show that they participate in the induction of inflammation.Firstly,platelets contain and release cytokines and immune mediators.And platelets are able to modulate and regulate the function of surrounding cells by adhesion molecules or by the release of various factors.

  20. The Implementation of 2U Platelets Collected at the Huaian Blood Center%2U单采血小板的采集在淮安市中心血站的实施

    Institute of Scientific and Technical Information of China (English)

    滕平; 谢峰

    2015-01-01

    目的 为了保证献血者在捐献双份血小板后,体内剩余血小板仍能达到正常人水平,保障献血者的健康;另外也要使终产品符合国标的质量要求,达到患者的安全治疗需要的剂量. 方法 依据献血者体重和采前血小板计数,确定采集双份血小板的标准,对双份献血者体重的最低要求是:男≥60 kg,女≥55 kg;采前计数血小板的最低值为≥200×109/L.结果 经血细胞分离机采集后,对献血者重新抽样检查和对终产品进行验证,采集双份血小板后,献血者体内剩余血小板≥1.0×1011/L的正常人水平;采集后的终产品血小板计数≥5.0×1011/袋,白细胞≤5×108/袋,红细胞≤8× 109/袋,都能达到国标要求.结论 符合条件的献血者1次采集双份血小板安全可行,这样既能解决单采血小板供者的不足,减少患者输注血小板后抗体产生的机会,同时也可大大节约单采血小板成本.%Objective To ensure blood donors after double platelet donation, remaining in vivo platelet can still reach nor-mal level, to keep the donors of health;in addition to the final products to meet the requirements of the national standard of quality, to reach the safe treatment of the patients required dose. Methods According to the blood donation weight and re-covery of platelet count, the criteria for determining double samples of platelet, double blood donation is the weight of the minimum requirements: male is more than or equal to 60 kg, female is more than or equal to 55 kg. The lowest values of platelet count is equal or more than 200×109/L. Results Blood cell separator after collection, the blood donors to sampling inspection and the final product verification, after double platelet collection and normal human level of blood donors in residual platelet is more than or equal to 1.0×1011/L; after collection of the final products platelet count is greater than or e-qual to 5.0 ×1011/bag, white blood cell is less than or

  1. Effect of Platelet-Rich Plasma (PRP versus Autologous Whole Blood on Pain and Function Improvement in Tennis Elbow: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Seyed Ahmad Raeissadat

    2014-01-01

    Full Text Available Background. Autologous whole blood and platelet-rich plasma (PRP have been both suggested to treat chronic tennis elbow. The aim of the present study was to compare the effects of PRP versus autologous whole blood local injection in chronic tennis elbow. Methods. Forty patients with tennis elbow were randomly divided into 2 groups. Group 1 was treated with a single injection of 2 mL of autologous PRP and group 2 with 2 mL of autologous blood. Tennis elbow strap, stretching, and strengthening exercises were administered for both groups during a 2-month followup. Pain and functional improvements were assessed using visual analog scale (VAS, modified Mayo Clinic performance index for the elbow, and pressure pain threshold (PPT at 0, 4, and 8 weeks. Results. All pain and functional variables including VAS, PPT, and Mayo scores improved significantly in both groups 4 weeks after injection. No statistically significant difference was noted between groups regarding pain scores in 4-week follow-up examination (P>0.05. At 8-week reevaluations, VAS and Mayo scores improved only in PRP group (P<0.05. Conclusion. PRP and autologous whole blood injections are both effective to treat chronic lateral epicondylitis. PRP might be slightly superior in 8-week followup. However, further studies are suggested to get definite conclusion.

  2. Fate in humans of the plasticizer, DI (2-ethylhexyl) phthalate, arising from transfusion of platelets stored in vinyl plastic bags. [plasticizer migration into human blood from vinyl plastic bags during transfusion

    Science.gov (United States)

    Rubin, R. J.; Schiffer, C. A.

    1975-01-01

    Platelet concentrates were shown to contain 18-38 mg/100 ml of a phthalate plasticizer (DEHP) which arose by migration from the vinyl plastic packs in which the plateletes were prepared and stored. Transfusion of these platelets into 6 adult patients with leukemia resulted in peak blood plasma levels of DEHP ranging from 0.34 - 0.83 mg/100 ml. The blood levels fell mono-exponentially with a mean rate of 2.83 percent per minute and a half-life of 28.0 minutes. Urine was assayed by a method that would measure unchanged DEHP as well as all phthalic acid-containing metabolities. In two patients, at most 60 and 90% of the infused dose, respectively, was excreted in the urine collected for 24 hours post-transfusion. These estimates, however, could be high due to the simultaneous excretion of DEHP remaining from previous transfusions or arising from uncontrolled environmental exposures.

  3. Platelets and infection — an emerging role of platelets in viral infection

    Directory of Open Access Journals (Sweden)

    Alice eAssinger

    2014-12-01

    Full Text Available Platelets are anucleate blood cells that play a crucial role in the maintenance of hemostasis. While platelet activation and elevated platelet counts (thrombocytosis are associated with increased risk of thrombotic complications, low platelet counts (thrombocytopenia and several platelet function disorders increase the risk of bleeding. Over the last years more and more evidence has emerged that platelets and their activation state can also modulate innate and adaptive immune responses and low platelet counts have been identified as a surrogate marker for poor prognosis in septic patients.Viral infections often coincide with platelet activation. Host inflammatory responses result in the release of platelet activating mediators and a pro-oxidative and pro-coagulant environment, which favours platelet activation. However, viruses can also directly interact with platelets and megakaryocytes and modulate their function. Furthermore, platelets can be activated by viral antigen-antibody complexes and in response to some viruses B-lymphocytes also generate anti-platelet antibodies.All these processes contributing to platelet activation result in increased platelet consumption and removal and often lead to thrombocytopenia, which is frequently observed during viral infection. However, virus-induced platelet activation does not only modulate platelet count, but also shapes immune responses. Platelets and their released products have been reported to directly and indirectly suppress infection and to support virus persistence in response to certain viruses, making platelets a double-edged sword during viral infections. This review aims to summarize the current knowledge on platelet interaction with different types of viruses, the viral impact on platelet activation and platelet-mediated modulations of innate and adaptive immune responses.

  4. Platelets and infection - an emerging role of platelets in viral infection.

    Science.gov (United States)

    Assinger, Alice

    2014-01-01

    Platelets are anucleate blood cells that play a crucial role in the maintenance of hemostasis. While platelet activation and elevated platelet counts (thrombocytosis) are associated with increased risk of thrombotic complications, low platelet counts (thrombocytopenia) and several platelet function disorders increase the risk of bleeding. Over the last years, more and more evidence has emerged that platelets and their activation state can also modulate innate and adaptive immune responses and low platelet counts have been identified as a surrogate marker for poor prognosis in septic patients. Viral infections often coincide with platelet activation. Host inflammatory responses result in the release of platelet activating mediators and a pro-oxidative and pro-coagulant environment, which favors platelet activation. However, viruses can also directly interact with platelets and megakaryocytes and modulate their function. Furthermore, platelets can be activated by viral antigen-antibody complexes and in response to some viruses B-lymphocytes also generate anti-platelet antibodies. All these processes contributing to platelet activation result in increased platelet consumption and removal and often lead to thrombocytopenia, which is frequently observed during viral infection. However, virus-induced platelet activation does not only modulate platelet count but also shape immune responses. Platelets and their released products have been reported to directly and indirectly suppress infection and to support virus persistence in response to certain viruses, making platelets a double-edged sword during viral infections. This review aims to summarize the current knowledge on platelet interaction with different types of viruses, the viral impact on platelet activation, and platelet-mediated modulations of innate and adaptive immune responses.

  5. 双份机采血小板采集前后血常规结果分析%Study on the changes of the donor's blood cell counts before and after double apheresis platelets

    Institute of Scientific and Technical Information of China (English)

    伍娟; 孙革; 庄乃保; 熊恺轩; 王霞; 孙雄飞

    2015-01-01

    Objective To study the changes of the donor's blood routine indexes before and after double apheresis platelets, and then to explore the efficiency and the safety of double apheresis platelets. Methods The blood cell counts of 50 donors were examined by blood counting instrument before and after double apheresis plate-lets, and the data was analyzed on Paired Samples t-Test. Results After double apheresis platelets, PLT was signifi-cantly lower than that before double apheresis platelets (P0.05). And examination confirmed that the quality of the apheresis platelets products was up to specification, with the amount of platelets reaching 250 × 109/L and the qualification rate of 100%. Conclusion Double apheresis platelets can improve the efficiency and safety of platelets donation, and it would not affect the blood routine indexes of the donors.%目的:通过分析捐献双份机采血小板捐献者捐献前后血常规参数的变化,评价捐献双份机采血小板的效率和安全性。方法随机抽取本中心双份机采血小板捐献者50例,应用血细胞计数仪分别检测其献血前后血常规主要参数水平,并进行配对t检验。结果献血前与献血后PLT计数比较差异有统计学意义(P0.05),采集的血小板均能达到250×109/L,机采血小板合格率为100%,献血者无不适反应。结论双份机采血小板可以提高血小板采集效率,但不会明显影响捐献者血常规各主要参数的水平,机采双份血小板对捐献者不会有明显影响。

  6. Effect of desipramine treatment on /sup 3/H-imipramine binding in the blood platelets of depressed patients

    Energy Technology Data Exchange (ETDEWEB)

    Arora, R.C.; Meltzer, H.Y.

    1988-02-15

    Platelet imipramine binding (IB) was studied in depressed patients before and after treatment with desipramine for 17-28 days. Administration of desipramine was associated with a significant increase in Bmax. There was a trend for an increase in Kd, but it did not reach statistical significance. The net result of the changes in Bmax and Kd was an increase in IB. There were significant correlations between the change in depression ratings and pretreatment Kd, as well as the change in Kd during treatment. These results suggest that decreased IB is not a trait-dependent marker, but a state-dependent marker for depression. 46 references.

  7. Stability and reproducibility of ADVIA 120-measured red blood cell and platelet parameters in dogs, cats, and horses, and the use of reticulocyte haemoglobin content (CH(R)) in the diagnosis of iron deficiency

    NARCIS (Netherlands)

    Prins, M.; van Leeuwen, M.W.; Teske, E.

    2009-01-01

    Tijdschr Diergeneeskd. 2009 Apr 1;134(7):272-8. Stability and reproducibility of ADVIA 120-measured red blood cell and platelet parameters in dogs, cats, and horses, and the use of reticulocyte haemoglobin content (CH(R)) in the diagnosis of iron deficiency. Prins M, van Leeuwen MW, Teske E. Departm

  8. TISSUE-TYPE PLASMINOGEN-ACTIVATOR AND FIBRIN MONOMERS SYNERGISTICALLY CAUSE PLATELET DYSFUNCTION DURING RETRANSFUSION OF SHED BLOOD AFTER CARDIOPULMONARY BYPASS

    NARCIS (Netherlands)

    DEHAAN, J; SCHONBERGER, J; HAAN, J; VANOEVEREN, W; EIJGELAAR, A

    1993-01-01

    Reduced hemostasis and bleeding tendency after cardiopulmonary bypass results from platelet dysfunction induced by the bypass procedure. The causes of this acquired platelet dysfunction are still subject to discussion, although, recently, greater emphasis has been placed on an overstimulated fibrino

  9. Non-enzymatic modifications of prostaglandin H synthase 1 affect bifunctional enzyme activity - Implications for the sensitivity of blood platelets to acetylsalicylic acid.

    Science.gov (United States)

    Kassassir, Hassan; Siewiera, Karolina; Talar, Marcin; Stec-Martyna, Emilia; Pawlowska, Zofia; Watala, Cezary

    2016-06-25

    Due to its ability to inhibit the blood platelet PGHS-1, acetylsalicylic acid (ASA, Aspirin(®)) is widely used as a preventive agent in atherothrombotic diseases. However, its beneficial effects seem to be lower in diabetic patients, suggesting that protein glycation may impair effective ASA-mediated acetylation process. On the other hand, it is proposed that ASA can prevent some of the late complications of diabetes by lowering the extent of glycation at protein free amino groups. The aim of this work was to evaluate the extents of non-enzymatic N-glycosylation (glycation) and acetylation of blood platelet PGHS-1 (COX-1) and the competition between glycation and acetylation was investigated in order to demonstrate how these two reactions may compete against platelet PGHS-1. When PGHS-1 was incubated with glycating/acetylating agents (glucose, Glu; 1,6-bisphosphofructose, 1,6-BPF; methylglyoxal, MGO, acetylsalicylic acid, ASA), the enzyme was modified in 13.4 ± 1.6, 5.3 ± 0.5, 10.7 ± 1.2 and 6.4 ± 1.1 mol/mol protein, respectively, and its activity was significantly reduced. The prior glycation/carbonylation of PGHS-1 with Glu, 1,6-BPF or MGO decreased the extent of acetylation from 6.4 ± 1.1 down to 2.5 ± 0.2, 3.6 ± 0.3 and 5.2 ± 0.2 mol/mol protein, respectively, but the enzyme still remained susceptible to the subsequent inhibition of its activity with ASA. When PGHS-1 was first acetylated with ASA and then incubated with glycating/carbonylating agents, we observed the following reductions in the enzyme modifications: from 13.4 ± 1.6 to 8.7 ± 0.6 mol/mol protein for Glu, from 5.3 ± 0.5 to 3.9 ± 0.3 mol/mol protein for 1,6-BPF and from 10.7 ± 1.2 to 7.5 ± 0.5 mol/mol protein for MGO, however subsequent glycation/carbonylation did not significantly affect PGHS-1 function. Overall, our outcomes allow to better understand the structural aspects of the chemical competition between glycation and acetylation of PGHS-1.

  10. One size doesn’t fit all: Should we reconsider the introduction of cold-stored platelets in blood bank inventories?

    Science.gov (United States)

    Berzuini, Alessandra; Spreafico, Marta; Prati, Daniele

    2017-01-01

    Platelet concentrates are universally prepared with a standard method and stored for 5 days at room temperature (20–24°C) in gentle agitation. Currently, there is a renewed interest in the possibility of storing platelet concentrates below the standard temperatures. In fact, cold platelets might be more effective in bleeding patients and have a lower risk of bacterial transmission. Inventories including platelets at different temperatures may favour patient-centred strategies for prophylactic or therapeutic transfusions.

  11. Single Double Apheresis Platelets Collected Before and After the Change of Blood Routine%单双份机采血小板采集前后血常规变化

    Institute of Scientific and Technical Information of China (English)

    王芳; 龚宏伟

    2016-01-01

    Objective Through the monitoring of the single and double apheresis platelet donors before and after blood collection, evaluation of effects of one or two of platelet donors. Methods From the station in 2015 September, a single double apheresis platelet donors in 30 cases, were measured before and after blood collection with platelet count instrument, And the main parameters of the blood platelet (Hb, Hct, Plt) analysis.Results Blood collection by one or two platelets before and after blood were compared respectively, the hemoglobin concentration (Hb), hematocrit (Hct), there was no statistically signiifcant difference (P>0.05), The difference of platelet count (Plt) was statistically signiifcant (P<0.05), especially double platelets, peripheral blood platelet decreased more, but still in the normal range.Conclusion The acquisition of one or two platelets is reasonable and feasible, there was no signiifcant effect on the health of blood, has important signiifcance to relieve the tension of clinical platelet supply.%目的:通过对单份、双份机采血小板的献血者采集前、后血常规的监测,评价采单份或双份血小板对献血者的影响。方法抽取本站2015年9月份的单份、双份机采血小板的献血者各30例,用血小板计数仪分别检测其采集前、后的血常规,并对血小板血常规的主要参数(Hb、Hct、Plt)进行分析。结果采单份或双份血小板的献血者采集前、后的血常规分别比较,其中血红蛋浓度(Hb)、红细胞比容(Hct),差异无统计学意义(P>0.05),血小板计数(Plt)差异有统计学意义(P<0.05),特别是采双份血小板,外周血的血小板相对下降较多,但仍在正常范围。结论采集单份或双份血小板都是合理可行的,对献血者身体健康无明显影响,对缓解临床血小板供应的紧张局面具有重要意义。

  12. Platelet Function Tests in Bleeding Disorders.

    Science.gov (United States)

    Lassila, Riitta

    2016-04-01

    Functional disorders of platelets can involve any aspect of platelet physiology, with many different effects or outcomes. These include platelet numbers (thrombocytosis or thrombocytopenia); changes in platelet production or destruction, or capture to the liver (Ashwell receptor); altered adhesion to vascular injury sites and/or influence on hemostasis and wound healing; and altered activation or receptor functions, shape change, spreading and release reactions, procoagulant and antifibrinolytic activity. Procoagulant membrane alterations, and generation of thrombin and fibrin, also affect platelet aggregation. The above parameters can all be studied, but standardization and quality control of assay methods have been limited despite several efforts. Only after a comprehensive clinical bleeding assessment, including family history, information on drug use affecting platelets, and exclusion of coagulation factor, and tissue deficits, should platelet function testing be undertaken to confirm an abnormality. Current diagnostic tools include blood cell counts, platelet characteristics according to the cell counter parameters, peripheral blood smear, exclusion of pseudothrombocytopenia, whole blood aggregometry (WBA) or light transmission aggregometry (LTA) in platelet-rich plasma, luminescence, platelet function analysis (PFA-100) for platelet adhesion and deposition to collagen cartridges under blood flow, and finally transmission electron microscopy to exclude rare structural defects leading to functional deficits. The most validated test panels are included in WBA, LTA, and PFA. Because platelets are isolated from their natural environment, many simplifications occur, as circulating blood and interaction with vascular wall are omitted in these assays. The target to reach a highly specific platelet disorder diagnosis in routine clinical management can be exhaustive, unless needed for genetic counseling. The elective overall assessment of platelet function disorder

  13. 单双份机采血小板采集前后血常规对比分析%Contrastive analysis of blood routine results before and after single and double apheresis platelet in donors

    Institute of Scientific and Technical Information of China (English)

    伍娟; 熊恺轩; 孙革; 王霞; 田怡; 张琳; 孙雄飞

    2015-01-01

    Objective To evaluate the efficiency and safety of double apheresis platelets by analyzing the changes of blood routine parameters results before and after single and double apheresis platelet in donors. Methods Each 50 donors of sin-gle and double apheresis platelet were respectively extracted in the Shenzhen Municipal Blood Center from June 2013 to June 2014 and the levels of blood routine main parameters were detected by the blood counting instrument before and after double a-pheresis platelets. The obtained data were performed the contrastive analysis by the SPSS software. Results The peripheral blood WBC count had no statistical difference between before and after single and double apheresis platelet (P>0.05),while Hb concen-tration,peripheral red blood cell(RBC) count,Hct and Plt had statistical differences(P0.05);WBC,Hb,RBC and Hct after single and double aphere sis platelets also had no statistical differences(P>0.05),but Plt had statistical difference between single and double apheresis platelet(P0.05),而血红蛋白浓度(Hb)、外周血红细胞计数(RBC)、血细胞比容(Hct)、血小板计数(Plt)比较,差异均有统计学意义(P<0.05);单、双份机采血小板前,WBC、Hb、RBC、Hct、Plt比较,差异均无统计学意义(P>0.05);单、双份机采血小板后,WBC、Hb、RBC、Hct比较,差异均无统计学意义(P>0.05),而二者Plt比较,差异有统计学意义(P<0.05)。单、双份机采血小板合格率均达到100%,且献血者无不适反应。结论定期双份机采血小板对献血者是安全的,可以提高血小板采集效率,但不会明显影响献血者血常规各主要参数的水平。

  14. Blood Count Tests

    Science.gov (United States)

    Your blood contains red blood cells (RBC), white blood cells (WBC), and platelets. Blood count tests measure the number and types of cells in your blood. This helps doctors check on your overall health. ...

  15. Platelets, inflammation and tissue regeneration.

    Science.gov (United States)

    Nurden, Alan T

    2011-05-01

    Blood platelets have long been recognised to bring about primary haemostasis with deficiencies in platelet production and function manifesting in bleeding while upregulated function favourises arterial thrombosis. Yet increasing evidence indicates that platelets fulfil a much wider role in health and disease. First, they store and release a wide range of biologically active substances including the panoply of growth factors, chemokines and cytokines released from a-granules. Membrane budding gives rise to microparticles (MPs), another active participant within the blood stream. Platelets are essential for the innate immune response and combat infection (viruses, bacteria, micro-organisms). They help maintain and modulate inflammation and are a major source of pro-inflammatory molecules (e.g. P-selectin, tissue factor, CD40L, metalloproteinases). As well as promoting coagulation, they are active in fibrinolysis; wound healing, angiogenesis and bone formation as well as in maternal tissue and foetal vascular remodelling. Activated platelets and MPs intervene in the propagation of major diseases. They are major players in atherosclerosis and related diseases, pathologies of the central nervous system (Alzheimers disease, multiple sclerosis), cancer and tumour growth. They participate in other tissue-related acquired pathologies such as skin diseases and allergy, rheumatoid arthritis, liver disease; while, paradoxically, autologous platelet-rich plasma and platelet releasate are being used as an aid to promote tissue repair and cellular growth. The above mentioned roles of platelets are now discussed.

  16. Platelet-rich plasma preparation using three devices : Implications for platelet activation and platelet growth factor release

    NARCIS (Netherlands)

    Everts, Peter A. M.; Mahoney, Christine Brown; Hoffmann, Johannes J. M. L.; Schonberger, Jacques P. A. M.; Box, Henk A. M.; Van Zundert, Andre; Knape, Johannes T. A.

    2006-01-01

    Background: In this study, three commercial systems for the preparation of platelet-rich plasma (PRP) were compared and platelet growth factors release was measured. Methods: Ten healthy volunteers donated whole blood that was fractionated by a blood cell separator, and a table-top centrifuge to pre

  17. Determination of vascular endothelial growth factor (VEGF) in circulating blood: significance of VEGF in various leucocytes and platelets

    DEFF Research Database (Denmark)

    Werther, K; Christensen, Ib Jarle; Nielsen, Hans Jørgen

    2002-01-01

    . In corresponding blood samples, automated complete blood count was performed, and the number of each cell type was correlated to VEGF concentrations in plasma, serum and lysed whole blood. Finally, the impact of increasing clotting time on the release of VEGF to serum was analysed. RESULTS: Isolated neutrophils......AIM: The sources of increased vascular endothelial growth factor (VEGF) concentrations in peripheral blood from cancer patients are not known in detail. The aim of the present study was to evaluate correlations between the VEGF content in isolated leucocyte subpopulations and VEGF concentrations...... in plasma, serum and lysed whole blood. METHODS: In 51 colorectal cancer (CRC) patients, circulating T-lymphocytes, B-lymphocytes, monocytes, and granulocytes were isolated by means of immunomagnetic separation. Subsequently, the isolated cells were lysed and VEGF contents in the lysates were determined...

  18. Platelet satellitism in infectious disease?

    Science.gov (United States)

    Laskaj, Renata; Sikiric, Dubravka; Skerk, Visnja

    2015-01-01

    Background Platelet satellitism is a phenomenon of unknown etiology of aggregating platelets around polymorphonuclear neutrophils and other blood cells which causes pseudothrombocytopenia, visible by microscopic examination of blood smears. It has been observed so far in about a hundred cases in the world. Case subject and methods Our case involves a 73-year-old female patient with a urinary infection. Biochemical serum analysis (CRP, glucose, AST, ALT, ALP, GGT, bilirubin, sodium, potassium, chloride, urea, creatinine) and blood cell count were performed with standard methods on autoanalyzers. Serum protein fractions were examined by electrophoresis and urinalysis with standard methods on autoanalyzer together with microscopic examination of urine sediment. Erythrocyte sedimentation rate, blood culture and urine culture tests were performed with standard methods. Results Due to typical pathological values for bacterial urinary infection, the patient was admitted to the hospital. Blood smear examination revealed phenomenon, which has persisted for three weeks after the disease has been cured. Blood smears with EDTA as an anticoagulant had platelet satellitism whereas the phenomenon was not observed in tubes with different anticoagulants (Na, Li-heparin) and capillary blood. Discussion We hypothesize that satellitism was induced by some immunological mechanism through formation of antibodies which have mediated platelets binding to neutrophil membranes and vice versa. Unfortunately we were unable to determine the putative trigger for this phenomenon. To our knowledge this is the second case of platelet satellitism ever described in Croatia. PMID:26110042

  19. Platelet aggregation following trauma

    DEFF Research Database (Denmark)

    Windeløv, Nis A; Sørensen, Anne M; Perner, Anders

    2014-01-01

    We aimed to elucidate platelet function in trauma patients, as it is pivotal for hemostasis yet remains scarcely investigated in this population. We conducted a prospective observational study of platelet aggregation capacity in 213 adult trauma patients on admission to an emergency department (ED......). Inclusion criteria were trauma team activation and arterial cannula insertion on arrival. Blood samples were analyzed by multiple electrode aggregometry initiated by thrombin receptor agonist peptide 6 (TRAP) or collagen using a Multiplate device. Blood was sampled median 65 min after injury; median injury...... severity score (ISS) was 17; 14 (7%) patients received 10 or more units of red blood cells in the ED (massive transfusion); 24 (11%) patients died within 28 days of trauma: 17 due to cerebral injuries, four due to exsanguination, and three from other causes. No significant association was found between...

  20. Stability and reproducibility of ADVIA 120-measured red blood cell and platelet parameters in dogs, cats, and horses, and the use of reticulocyte haemoglobin content (CH(R)) in the diagnosis of iron deficiency.

    Science.gov (United States)

    Prins, M; van Leeuwen, M W; Teske, E

    2009-04-01

    Modern laser-based haematology analysers such as the ADVIA 120 have species-specific software and offer the possibility of assessing new haematological parameters. These parameters have yet to be evaluated, and as these analysers are often used in referral laboratories, it is important to know whether the values of haematological parameters change during sample transport. Therefore, samples of EDTA-anticoagulated blood from nine healthy dogs and EDTA- and citrate-anticoagulated blood from six healthy horses were collected and stored at room temperature for 72 and 48 hours, respectively. In canine samples, WBC and the red blood cell parameters Hb, Hb(cell), Ht, MCV, and MCHC changed significantly after only 24 hours of storage. Thus if canine blood samples need to be stored for 24 hours or longer, Hb, RBC, and MCH would appear to be more reliable parameters than Ht, Hb(cell), MCV, and MCHC. The cytoplasmic haemoglobin content (CH(R)) remained stable up to 48 hours. Both dog and horse platelet numbers were stable over time when blood was anticoagulated with EDTA. Of the platelet-derived parameters, MPC was already significantly lower 2 hours after collection of equine blood samples and was also significantly lower 24 hours after collection of canine blood samples. In contrast, MPV levels were significantly higher 48 hours after sample collection. Initial platelet numbers and platelet parameters were significantly different in citrate-anticoagulated blood and EDTA-anticoagulated blood, and platelet numbers and MPM decreased significantly in citrate-anticoagulated blood samples after only 4 hours of storage. After reference intervals for CH(R) had been established using samples from 53 non-anaemic dogs and 150 non-anaemic cats, the use of CH(R) to detect iron deficiency anaemia was tested in 63 dogs and 55 cats with different diseases. With the help of ROC curves, the optimal cut-off point was determined to be 1.22 fmol in dogs and 0.88 fmol in cats, resulting in a

  1. Could mean platelet volume among complete blood count parameters be a surrogate marker of metabolic syndrome in pre-pubertal children?

    Science.gov (United States)

    Aypak, Cenk; Türedi, Ozlem; Bircan, Mustafa A; Yüce, Adnan

    2014-01-01

    Interest in childhood metabolic syndrome (MetS) has increased substantially due to the increasing prevalence of childhood obesity on a global scale. Early recognition of MetS is critical in order to delay the development of cardiovascular disease (CVD). In this study, we evaluated the relationship between complete blood count (CBC) parameters and MetS among pre-pubertal children which may provide evidence in support of using low cost, readily available clinical haematological parameters for the detection of MetS. A retrospective analysis was carried out on 330 (125 lean vs. 205 overweight) Turkish pre-pubertal children who attend to a paediatric outpatient clinic. Age, gender, puberty, body mass index, CBC parameters, cardiometabolic risk factors including lipid profiles, high sensitive serum reactive protein (hsCRP) and insulin resistance index calculated by homeostasis model assessment (HOMA-IR) were evaluated and compared among lean, overweight children and children with MetS. The mean age of the study population was 7.4 ± 1.9 years. In both gender, the mean values of mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were significantly lower and red blood cell (RBC), platelet (PLT) counts were significantly higher in overweight children. Overall, 8.4% (n = 28) of patients met the criteria of MetS. Children with MetS had higher levels of PLT and lower levels of mean platelet volume (MPV). Of all the haematological parameters analysed, PLT was positively, whereas MPV was negatively correlated with MetS in girls. In addition, MPV was inversely correlated with fasting blood glucose, HOMA-IR, low density lipoprotein-cholesterol (LDL-C) and low density lipoprotein-cholesterol/high density lipoprotein-cholesterol (LDL-C/HDL-C) ratio in girls after adjusting for confounding factors. The risk analyses of MetS in terms of MPV quartiles showed that the adjusted OR (95% CI) for the lowest vs. the

  2. Effects of Xuezhikang Capsule(血脂康胶囊) on Blood Lipids,Platelet Activation and Coagulation-Fibrinolysis Activity in Patients with Hyperlipidemia

    Institute of Scientific and Technical Information of China (English)

    刘志高; 余细勇

    2004-01-01

    Objective: To investigate the effects of Xuezhikang capsule (XZK, 血脂康胶囊) on blood lipids level, platelet activation and coagulation-fibrinolysis activity in patients with hyerlipidemia. Methods:Seventy-six patients of hyperlipidemia were randomly divided into two groups, the XZK group (n = 38) treated with XZK 600mg, taken two times per day and the Simvastatin (SIM) group (n = 38) treated with SIM 20mg per day, with the treatment lasting 8 weeks for both groups. Levels of fasting serum lipids, including total cholesterol (TC), triglyceride (TG), high and low density l ipoprotein cholesterol (HDL-C and LDL-C),plasma GMP-140, fibrinogen (FIB), tissue plasminogen activator (t-PA), plasminogen activator inhibitor type-1 (PAl-) and prothrombin time (PT) were all measured before and 8 weeks after treatment. Data were compared before and after treatment and also compared with those measured in 20 healthy subjects of control. Results: Before treantment the levels of TC, TG and LDL-C were obviously higher and HDL-C level was significantly lower in hyperlipidemia patients than those in healthy subjects ( P<0.05 or P<0.01). After 4-8 weeks of XZK treatment, the levels of TC, TG, LDL-C and FIB and activities of GMP-140 and PAl-1 were obviously lowered (P<0.05 or P<0.01). But in the SIM group there was no obvious change in FIB (P>0.05), instead it showed obvious increase of HDL-C and decrease of TC and LDL-C after treatment ( P<0.05 or P<0.01). Conclusion: XZK could inhibit platelet activity and improve coagulation-fibrinolysis function, besides its lipids lowering effect.

  3. Platelets: crossroads of immunity and hemostasis.

    Science.gov (United States)

    Jenne, Craig N

    2014-07-31

    In this issue of Blood, Koupenova and colleagues report that platelets express functional TOLL-like receptor 7 (TLR7) and contribute to host survival during viral infection. Through a series of experiments utilizing mice deficient for TLR7 together with adoptive transfer of wild-type platelets, Koupenova et al demonstrate that platelets specifically respond to viral analogs and intact virus, leading to platelet activation and binding to various leukocyte subsets. Perhaps most importantly, this platelet activation appears absolutely essential for host survival during infection with some viral pathogens such as encephalomyocarditis virus (EMCV).

  4. The relationship between the level of activation markers of platelets in peripheral blood around operation and lung cancer%肺癌患者外周血血小板活化标志物水平及其临床意义

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective: To investigate the relationship between the activation markers of platelets and the lung cancer.Methods: Based on international stages of lung cancer in 1997, lung cancer patients of 120 cases diagnosed by pathology as well as with operation indication were selected as the experimental group.During the process of experiment, 60 cases concluded as healthy in the physical examination were chosen as control group.The activation markers of platelets were detected by FCM method.The experimental result would be processed by SPSS 11.5.Results: The level of activation markers of platelets in peripheral blood of lung cancer patients was significantly higher than those healthy people(P<0.01).The level of activation markers of platelets in peripheral blood of lung cancer patients on the seventh postoperative day was significantly lower than that before operation and on the first postoperative day(P<0.01).The level of activation markers of platelets in peripheral blood of lung cancer patients was closely related to the size of the primary tumor, lymph node status and stages, but not to the grade of cell differentiation, type of tumor, age, sex of the patients(P>0.05).Conclusion: Elevation of the level of activation markers of platelets in peripheral blood exists in lung cancer patients and the levels of activation marker of platelets plays an important role in tumor growth and lymphatic metastasis.The levels of activation markers of platelets maybe a predictor for prognosis.

  5. 围产期妇女外周血大血小板与纤维蛋白原相关性分析%Analysis of the relationship between peripheral blood platelet and fibrinogen of perinatal women

    Institute of Scientific and Technical Information of China (English)

    张燕; 李飞

    2014-01-01

    Objective To investigate the relationship between peripheral blood platelet and fibrinogen of peri-natal women.Methods 309 cases of perinatal women were collected,peripheral blood platelet and fibrinogen tested by manual method and VASTECCA7000 coagulation analyzer.Results The large platelets positive rate was 53.39%in 309 cases ,122 cases of normal women′s big platelet positive rate was 13.11%.It′s a significant difference be-tween two group(P<0.05).90 cases of patients with large platelet and fibrinogen increased.75 cases of patients with large platelet and fibrinogen was not increased .52 cases of patients with negative large platelet and fibrinogen in-creased.92 cases of patients with negative large platelet and fibrinogen was not increased .There were significantly different between large platelet and fibrinogen (P<0.05).Conclusion the perinatal maternal peripheral blood plate-let than normal women,perinatalmaternal peripheral blood platelet increased along with the increased fiberprotein.%目的:对围产期妇女外周血大血小板和纤维蛋白原的分析探讨。方法运用手工法和 VASTEC CA7000凝血分析仪分别对309例围产期妇女外周血进行直接涂片镜检和纤维蛋白原的检测。结果309例围产期妇女大血小板阳性率为53.39%,122例正常妇女大血小板阳性率为13.11%。围产组与正常组差异有统计学意义(P <0.05);大血小板阳性,纤维蛋白原增高的为90例,大血小板阳性,纤维蛋白原不增高的为75例,大血小板阴性,纤维蛋白原增高的为52例,大血小板阴性,纤维蛋白原不增高的为92例。大血小板与纤维蛋白原的相关分析差异有统计学意义(P <0.05)。结论围产期孕妇外周血中大血小板较正常妇女多,围产期孕妇外周血大血小板增多伴随着纤维蛋白增高。

  6. Blood platelets and coagulation. Annual progress report, June 1, 1975--May 31, 1976. [/sup 75/Se tracer study of effects of thrombopoietin on platelet production in mice and rabbits

    Energy Technology Data Exchange (ETDEWEB)

    1976-01-01

    The primary emphasis during the past year has been extension of studies of platelet production and demonstration of a humoral agent (i.e., thrombopoietin) that regulates the production of platelets by megakaryocytes. Incorporation of selenomethionine-/sup 75/Se (/sup 75/SeM) into platelets was used to study the effect of partially purified fractions of plasma proteins upon platelet production in normal mice and rabbits. Significant increases in levels of /sup 75/SeM in circulating platelets were observed in mice that had received fractions prepared from the plasma of thrombocytopenic donors, that precipitated at (NH/sub 4/)/sub 2/SO/sub 4/ saturations of 60 to 80% and subsequently were eluted from DEAE cellulose and Sephadex G-100 columns under the conditions described. These data suggest that thrombopoiesis stimulating factor(s) (thrombopoietin), obtained from rabbits, is present in the plasma of thrombocytopenic donors, is not species specific, can be partially purified as described above, and can be detected by the production of increased rates of appearance of /sup 75/SeM in the platelets of normal mice.

  7. The accuracy of platelet counting in thrombocytopenic blood samples distributed by the UK National External Quality Assessment Scheme for General Haematology.

    Science.gov (United States)

    De la Salle, Barbara J; McTaggart, Paul N; Briggs, Carol; Harrison, Paul; Doré, Caroline J; Longair, Ian; Machin, Samuel J; Hyde, Keith

    2012-01-01

    A knowledge of the limitations of automated platelet counting is essential for the effective care of thrombocytopenic patients and management of platelet stocks for transfusion. For this study, 29 external quality assessment specimen pools with platelet counts between 5 and 64 × 10(9)/L were distributed to more than 1,100 users of 23 different hematology analyzer models. The same specimen pools were analyzed by the international reference method (IRM) for platelet counting at 3 reference centers. The IRM values were on average lower than the all-methods median values returned by the automated analyzers. The majority (~67%) of the automated analyzer results overestimated the platelet count compared with the IRM, with significant differences in 16.5% of cases. Performance differed between analyzer models. The observed differences may depend in part on the nature of the survey material and analyzer technology, but the findings have implications for the interpretation of platelet counts at levels of clinical decision making.

  8. Platelets in inflammation and infection.

    Science.gov (United States)

    Jenne, Craig N; Kubes, Paul

    2015-01-01

    Although platelets are traditionally recognized for their central role in hemostasis, many lines of research clearly demonstrate these rather ubiquitous blood components are potent immune modulators and effectors. Platelets have been shown to directly recognize, sequester and kill pathogens, to activated and recruit leukocytes to sites of infection and inflammation, and to modulate leukocyte behavior, enhancing their ability to phagocytose and kill pathogens and inducing unique effector functions, such as the production of Neutrophil Extracellular Traps (NETs). This multifaceted response to infection and inflammation is due, in part, to the huge array of soluble mediators and cell surface molecules expressed by platelets. From their earliest origins as primordial hemocytes in invertebrates to their current form as megakaryocyte-derived cytoplasts, platelets have evolved to be one of the key regulators of host intravascular immunity and inflammation. In this review, we present the diverse roles platelets play in immunity and inflammation associated with autoimmune diseases and infection. Additionally, we highlight recent advances in our understanding of platelet behavior made possible through the use of advanced imaging techniques that allow us to visualize platelets and their interactions, in real-time, within the intact blood vessels of a living host.

  9. Transfusion of platelets, but not of red blood cells, is independently associated with nosocomial infections in the critically ill

    NARCIS (Netherlands)

    Engele, Leo J.; Straat, Marleen; van Rooijen, Ingeborg H M; de Vooght, Karen M K; Cremer, Olaf L.; Schultz, Marcus J.; Bos, Lieuwe D J; Juffermans, Nicole P.

    2016-01-01

    Background: Red blood cell (RBC) transfusion has been associated with nosocomial infection in the critically ill patients. However, this association may be confounded by length of stay, as prolonged intensive care unit (ICU stay) increases both risk of infection and risk of transfusion. Also, it is

  10. Platelets kill intraerythrocytic malarial parasites and mediate survival to infection.

    Science.gov (United States)

    McMorran, Brendan J; Marshall, Vikki M; de Graaf, Carolyn; Drysdale, Karen E; Shabbar, Meriam; Smyth, Gordon K; Corbin, Jason E; Alexander, Warren S; Foote, Simon J

    2009-02-01

    Platelets play a critical role in the pathogenesis of malarial infections by encouraging the sequestration of infected red blood cells within the cerebral vasculature. But platelets also have well-established roles in innate protection against microbial infections. We found that purified human platelets killed Plasmodium falciparum parasites cultured in red blood cells. Inhibition of platelet function by aspirin and other platelet inhibitors abrogated the lethal effect human platelets exert on P. falciparum parasites. Likewise, platelet-deficient and aspirin-treated mice were more susceptible to death during erythrocytic infection with Plasmodium chabaudi. Both mouse and human platelets bind malarial-infected red cells and kill the parasite within. These results indicate a protective function for platelets in the early stages of erythrocytic infection distinct from their role in cerebral malaria.

  11. Platelet inhibition by nitrite is dependent on erythrocytes and deoxygenation.

    Directory of Open Access Journals (Sweden)

    Sirada Srihirun

    Full Text Available BACKGROUND: Nitrite is a nitric oxide (NO metabolite in tissues and blood, which can be converted to NO under hypoxia to facilitate tissue perfusion. Although nitrite is known to cause vasodilation following its reduction to NO, the effect of nitrite on platelet activity remains unclear. In this study, the effect of nitrite and nitrite+erythrocytes, with and without deoxygenation, on platelet activity was investigated. METHODOLOGY/FINDING: Platelet aggregation was studied in platelet-rich plasma (PRP and PRP+erythrocytes by turbidimetric and impedance aggregometry, respectively. In PRP, DEANONOate inhibited platelet aggregation induced by ADP while nitrite had no effect on platelets. In PRP+erythrocytes, the inhibitory effect of DEANONOate on platelets decreased whereas nitrite at physiologic concentration (0.1 µM inhibited platelet aggregation and ATP release. The effect of nitrite+erythrocytes on platelets was abrogated by C-PTIO (a membrane-impermeable NO scavenger, suggesting an NO-mediated action. Furthermore, deoxygenation enhanced the effect of nitrite as observed from a decrease of P-selectin expression and increase of the cGMP levels in platelets. The ADP-induced platelet aggregation in whole blood showed inverse correlations with the nitrite levels in whole blood and erythrocytes. CONCLUSION: Nitrite alone at physiological levels has no effect on platelets in plasma. Nitrite in the presence of erythrocytes inhibits platelets through its reduction to NO, which is promoted by deoxygenation. Nitrite may have role in modulating platelet activity in the circulation, especially during hypoxia.

  12. Platelet function tests: a comparative review

    Directory of Open Access Journals (Sweden)

    Paniccia R

    2015-02-01

    Full Text Available Rita Paniccia,1,2 Raffaella Priora,1,2 Agatina Alessandrello Liotta,2 Rosanna Abbate1,2 1Department of Experimental and Clinical Medicine, Thrombosis Center, University of Florence, Florence, Italy; 2Department of Heart and Vessels, Azienda Ospedaliero-Universitaria Careggi, Florence, Italy Abstract: In physiological hemostasis a prompt recruitment of platelets on the vessel damage prevents the bleeding by the rapid formation of a platelet plug. Qualitative and/or quantitative platelet defects promote bleeding, whereas the high residual reactivity of platelets in patients on antiplatelet therapies moves forward thromboembolic complications. The biochemical mechanisms of the different phases of platelet activation – adhesion, shape change, release reaction, and aggregation – have been well delineated, whereas their complete translation into laboratory assays has not been so fulfilled. Laboratory tests of platelet function, such as bleeding time, light transmission platelet aggregation, lumiaggregometry, impedance aggregometry on whole blood, and platelet activation investigated by flow cytometry, are traditionally utilized for diagnosing hemostatic disorders and managing patients with platelet and hemostatic defects, but their use is still limited to specialized laboratories. To date, a point-of-care testing (POCT dedicated to platelet function, using pertinent devices much simpler to use, has now become available (ie, PFA-100, VerifyNow System, Multiplate Electrode Aggregometry [MEA]. POCT includes new methodologies which may be used in critical clinical settings and also in general laboratories because they are rapid and easy to use, employing whole blood without the necessity of sample processing. Actually, these different platelet methodologies for the evaluation of inherited and acquired bleeding disorders and/or for monitoring antiplatelet therapies are spreading and the study of platelet function is strengthening. In this review, well

  13. Recombinant human thrombopoietin in combination with granulocyte colony-stimulating factor enhances mobilization of peripheral blood progenitor cells, increases peripheral blood platelet concentration, and accelerates hematopoietic recovery following high-dose chemotherapy.

    Science.gov (United States)

    Somlo, G; Sniecinski, I; ter Veer, A; Longmate, J; Knutson, G; Vuk-Pavlovic, S; Bhatia, R; Chow, W; Leong, L; Morgan, R; Margolin, K; Raschko, J; Shibata, S; Tetef, M; Yen, Y; Forman, S; Jones, D; Ashby, M; Fyfe, G; Hellmann, S; Doroshow, J H

    1999-05-01

    Lineage-specific growth factors mobilize peripheral blood progenitor cells (PBPC) and accelerate hematopoietic recovery after high-dose chemotherapy. Recombinant human thrombopoietin (rhTPO) may further increase the progenitor-cell content and regenerating potential of PBPC products. We evaluated the safety and activity of rhTPO as a PBPC mobilizer in combination with granulocyte colony-stimulating factor (G-CSF) in 29 breast cancer patients treated with high-dose chemotherapy followed by PBPC reinfusion. Initially, patients received escalating single doses of rhTPO intravenously (IV) at 0.6, 1.2, or 2.4 micrograms/kg, on day 1. Subsequent patients received rhTPO 0.6 or 0.3 micrograms/kg on days -3, -1, and 1, or 0.6 micrograms/kg on days -1 and 1. G-CSF, 5 micrograms/kg IV or subcutaneously (SC) twice daily, was started on day 3 and continued through aphereses. Twenty comparable, concurrently and identically treated patients (who were eligible and would have been treated on protocol but for the lack of study opening) mobilized with G-CSF alone served as comparisons. CD34(+) cell yields were substantially higher with the first apheresis following rhTPO and G-CSF versus G-CSF alone: 4.1 x 10(6)/kg (range, 1.3 to 17.6) versus 0.8 x 10(6)/ kg (range, 0.3 to 4.2), P =.0003. The targeted minimum yield of 3 x 10(6) CD34(+) cells/kg was procured following a single apheresis procedure in 61% of the rhTPO and G-CSF-mobilized group versus 10% of G-CSF-mobilized patients (P =.001). In rhTPO and G-CSF mobilized patients, granulocyte (day 8 v 9, P =.0001) and platelet recovery (day 9 v 10, P =.07) were accelerated, and fewer erythrocyte (3 v 4, P =.02) and platelet (4 v 5, P =.02) transfusions were needed compared with G-CSF-mobilized patients. Peripheral blood platelet counts, following rhTPO and G-CSF, were increased by greater than 100% and the platelet content of PBPC products by 60% to 110% on the first and second days of aphereses (P rhTPO at 0.6 microgram/kg. rhTPO is

  14. [Four cases of pseudothrombocytopenia due to platelet cold agglutinins].

    Science.gov (United States)

    Kurata, Yoshiyuki; Hayashi, Satoru; Jouzaki, Kiyoshi; Konishi, Ichirou; Kashiwagi, Hirokazu; Tomiyama, Yoshiaki

    2006-08-01

    We report 4 cases of pseudothrombocytopenia due to platelet cold agglutinins. Case 1 was a 57 y.o. female whose platelet count was 97 x 10(3)/microl. Case 2 was a 37 y.o. male with a platelet count of 96 x 10(3)/microl. Case 3 was a 74 y.o. male with a platelet count of 28 x 10(3)/microl. Case 4 was a 62 y.o. female whose platelet count was 34 x 10(3)/microl. The platelet counts in these 4 cases were decreased and blood smears showed platelet clumping in blood drawn in a tube without anticoagulant just after withdrawal, as well as in blood drawn in a tube with anticoagulant. The platelets from these patients agglutinated at a temperature below 10 degrees C (case 1 and 4) and 24 degrees C (case 2). The immunoglobulin class of the platelet cold agglutinins in cases 1, 2 and 4 was IgM. Agglutinated platelets showed no activation marker, such as CD62P, CD63 or CD40L, on the surface of the platelets. The target antigen of cold agglutinins was GPIIb-IIIa in cases 1 and 2. We considered that the detection of platelet agglutination in blood without anticoagulant is important to diagnose pseudothrombocytopenia due to platelet cold agglutinins. Although this disease is considered to be very rare, we suspect that this disease may be misdiagnosed as pseudothrombocytopenia due to the presence of an anticoagulant, and overlooked.

  15. Platelet-rich fibrin: Evolution of a second-generation platelet concentrate

    Directory of Open Access Journals (Sweden)

    Sunitha Raja V

    2008-01-01

    Full Text Available Platelet-rich plasma (PRP is a platelet concentrate that has been used widely to accelerate soft-tissue and hard-tissue healing. The preparation of PRP has been described by several authors. Platelet-rich fibrin (PRF was first described by Choukroun et al. in France. It has been referred to as a second-generation platelet concentrate, which has been shown to have several advantages over traditionally prepared PRP. Its chief advantages include ease of preparation and lack of biochemical handling of blood, which makes this preparation strictly autologous. This article describes the evolution of this novel platelet concentrate, referred to as PRF.

  16. 人体静脉血样采集管的不同内表面状态对血小板活化的影响%Effects of different inner face of human venous blood container on platelet activation

    Institute of Scientific and Technical Information of China (English)

    周迎春; 汤习锋; 许铭飞

    2008-01-01

    目的 研究人体静脉血样采集管的不同内表面状态对血小板活化的影响.方法 用聚环氧烷-聚二甲基硅氧烷共聚物(L722)、硅烷偶联剂对塑料管(PET)和玻璃管制膜,对L722玻璃管、L722 PET管、玻璃管、PET管、硅烷偶联剂制膜玻璃管及聚丙烯管(PP)内表面进行接触角分析.用上述材料的血样采集管采集血液标本并在室温下滚动混匀孵育110~60 min.用流式细胞术(FCM)检测血小板激活标志物CD62p.结果 不同材质及表面处理血液采集管的内表面的接触角大小在一定程度上反映了血小板活化率,但并不呈线性关系.PET管经L722表面改性后表达CD62p阳性的活化血小板百分率由(37.4±14.8)%下降到(21.9±12.4)%.玻璃管对表达CD62p阳性的活化血小板百分率为(54.5±18.6)%,明显大于PET管.玻璃管制膜后对血小板的激活明显减少,用硅烷偶联剂制膜的玻璃管表达CD62p阳性的活化血小板百分率为(28.3±8.2)%,明显低于L722制膜玻璃管.用PET作为基体材料经过L722表面处理后对血小板活化明显低于L722制膜的玻璃管的(41.5 ±15.9)%和用硅烷偶联剂制膜的玻璃管的(22.0±12.8)%.不同管对血小板活化时间进程显示:60 min L722 PET管和聚丙烯管的血小板活化与30 min的结果差异无统计学意义.结论 不同材质及表面处理血液盛装管所导致的不同表面能状态对血小板活化的影响有明显差异,硅油表面处理能有效改善血液采集管的血液相容性.FCM检测CD62p是评价血液收集管材料介导的血小板活化的灵敏指标,对建立血液盛装材料表面处理模型及筛选临床应用材料具有重要意义.%Objective To study the effects of different inner face status of human venous blood container on platelet activation. Methods The plastic( polyethene terephthalate,PET) and glass tubes were coated with polyalkyleneoxide modified polydimethylsiloxane(L722). The contact angles of L722

  17. Analysis on reasons of unqualified blood test results on apheresis platelets donors%机采血小板献血者血液检测不合格原因分析

    Institute of Scientific and Technical Information of China (English)

    邹韬; 杨松; 陈臻

    2015-01-01

    ObjectiveTo analyze the reasons of unqualified blood test results on apheresis platelets donors in Nanchong; to improve the recruitment strategy and pre-donor screening program.MethodsBlood test results on apheresis platelets donors in Nanchong from 2010 to 2014 were analyzed and counted.ResultsTotal unqualified rate of blood test on platelet from 2010 to 2014 was 2.09%, wherein unqualified rate of new donors was 5.51% and that of repeated donors was 1.36%. Unqualified rates of ALT, HBsAg, anti-HCV, anti-HIV, and anti-TP were 0.87%, 0.51%, 0.13%, 0.21% and 0.44%.ConclusionsApheresis platelets donors are recruited from stationary voluntary unpaid donors. Strengthening blood screening of blood donors can decrease unqualified rate of platelet detection.%目的:分析南充市机采血小板血液检测不合格原因,改进招募策略和献血前筛查方案。方法:对本市2010-2014年机采血小板血液检测结果进行分析统计。结果:2010-2014年血小板血液检测总不合格率为2.09%,其中首次献血者的不合格率为5.51%,重复献血者的不合格率为1.36%,不合格原因中ALT、HBsAg、抗-HCV、抗-HIV、抗-TP的不合格率分别为0.87%、0.51%、0.13%、0.21%、0.44%。结论:从固定自愿无偿献血者中招募机采血小板献血者、加强献血者血液筛查可降低机采血小板检测不合格率。

  18. 妊娠期糖尿病孕妇血小板活化指标变化研究%The study of the changes in the indexes of blood platelet activation of pregnant women with gestational diabetes

    Institute of Scientific and Technical Information of China (English)

    刘玉芝

    2014-01-01

    Objective:To study and analyze the changes in the indexes of blood platelet activation of pregnant women with gestational diabetes. Method:Selected 52 pregnant women with gestational diabetes in our hospital from July 2011 to April 2013 into the observation group and other 52 healthy patients of the same age and at the same period were selected into the control group.Compare the indexes of blood platelet activation of the two groups, and compare the detection level of pregnant women with different glycated hemoglobin level.Result:the indexes of blood platelet activation of the pregnant women in the observation group was higher than that of the control group. In the observation group, the detection level of pregnant women whose glycated hemoglobin level≥8.0%was higher than those whose glycated hemoglobin level<8.0%,P<0.05. The difference was statistically significant.Conclusion:the indexes of blood platelet activation of pregnant women with gestational diabetes presents a state of abnormally high and those whose glycated hemoglobin level was high have a high index of blood platelet activation.%目的:研究分析妊娠期糖尿病孕妇血小板活化指标的变化情况。方法:选取2011年7月~2013年8月本院的52例妊娠期糖尿病孕妇为观察组,并以同期同龄的52例健康孕妇为对照组,然后将两组孕妇的血小板活化指标进行比较,并比较不同糖化血红蛋白水平孕妇的检测水平。结果:观察组孕妇的血小板活化指标均高于对照组孕妇,且观察组孕妇中糖化血红蛋白≥8.0%者的检测水平高于糖化血红蛋白<8.0%者,P 均<0.05,均有显著性差异。结论:妊娠期糖尿病孕妇的血小板活化指标呈现异常升高的状态,且糖化血红蛋白较高者的血小板活化指标水平也较高。

  19. Platelet reactions to modified surfaces under dynamic conditions.

    Science.gov (United States)

    Rhodes, N P; Shortland, A P; Rattray, A; Williams, D F

    1998-12-01

    The influence of surfaces on the reactions of platelets in whole blood under laminar flow was investigated in a cone and plate viscometer. Citrated whole blood was exposed to steel, PMMA and PMMA modified with PEO at low (500 s(-1)) and high (4000 s(-1)) wall shear rates at room temperature for a period of 100 s. Treated blood samples were fixed with paraformaldehyde, stained with a monoclonal antibody for CD41 (platelet GPIIb/IIIa) conjugated with phycoerythrin and analyzed by flow cytometry. The reactions of platelets (microparticle generation and formation of platelet-platelet, platelet-red blood cell and red blood cell-microparticle aggregates) to these environments were quantified. Additionally, the size of platelet-platelet aggregates was assessed. The percentage platelet aggregation and numbers of microparticles generated were independent of surface type at any shear rate. The composition of the aggregates formed was influenced by the surface: at low and high shear rates PMMA caused the generation of platelet-platelet aggregates of the greatest size. The numbers of red blood cell-platelet and red blood cell-microparticle aggregates also varied depending on the surface. Fewer red blood cell-platelet aggregates were formed at higher shear rates, whereas the reverse was true for red blood cell-microparticle aggregates. It is concluded that these variations may help to explain the differential effects of surfaces to the induction of distant thrombotic events: microparticles may be protected from loss from the blood stream by their association with red blood cells at high shear rates.

  20. 攀枝花市机采血小板互助献血研究%Study on Apheresis Platelets under Mutual Assistance Blood Donation Pat-tern in Panzhihua City

    Institute of Scientific and Technical Information of China (English)

    左涛

    2014-01-01

    Objective To investigate the advantages and disadvantages of blood donation pattern of mutual assistance for apheresis platelet in Panzhihua City and provide basis for recruitment strategy on apheresis platelet. Methods The situations of 1089 cases of apheresis platelet blood donation from 2008 to 2013 were retrospectively analyzed. Results The retest failure rate for the 476 case of apheresis platelet blood donation under mutual assistance pattern was 3.15%, and that for the 613 cases under voluntary pattern was 0.82%. The former is significantly higher than the latter (χ2=8.107,P<0.01), among which the difference in anti-TP failure rate was statistically significant (χ2=10.379,P<0.005). The initial blood donation ratio for mutual assistance blood donation pattern reached 71.46%(341/476), while that for the voluntary apheresis platelet blood donation pattern was 0.98%(6/613), which differed significantly (χ2=616.180,P<0.001). Conclusion Blood donation pattern of mutual assistance for apheresis platelet relieves the shortage situation in platelet by certain degree, but also brings some hidden safety hazards.%目的:研究攀枝花市机采血小板互助献血模式的利弊,为机采血小板招募策略提供依据。方法对2008-2013年1089人次机采血小板献血情况进行回顾性分析。结果机采互助献血者476人次复检不合格率3.15%,自愿机采献血者613人次复检不合格率0.82%,前者明显大于后者(χ2=8.107,P<0.01),其中抗-TP不合格率差异有显著意义(χ2=10.379,P<0.005)。机采互助献血中初次献血率达71.64%(341/476),自愿机采献血中初次献血率仅0.98%(6/613),两种献血者的初次献血率差异有显著意义(χ2=616.180,P<0.001)。结论机采血小板互助献血在一定程度上缓解了血小板紧缺的状况,也带来一些安全隐患。

  1. Platelets promote bacterial dissemination in a mouse model of streptococcal sepsis.

    Science.gov (United States)

    Kahn, Fredrik; Hurley, Sinead; Shannon, Oonagh

    2013-01-01

    Platelets have been reported to contribute to inflammation and inflammatory disorders. In the present study, we demonstrate that platelets contribute to the acute response to bacterial infection in a mouse model of invasive Streptococcus pyogenes infection. Thrombocytopenia occurred rapidly in infected animals and this was associated with platelet activation, formation of platelet-neutrophil complexes and neutrophil activation. In order to assess the role of platelets during infection, platelets were depleted prior to infection. Platelet-depleted animals had significantly decreased platelet-neutrophil complex formation and neutrophil activation in response to infection. Importantly, significantly fewer bacteria disseminated to the blood, lungs, and spleen of platelet-depleted animals. Platelet-depleted animals did not decrease as significantly in weight as the infected control animals. The results demonstrate a previously unappreciated role for platelets during the pathophysiological response to infection, whereby S. pyogenes bacteria bind to platelets and platelets facilitate bacterial dissemination.

  2. Bone Augmentation in Rabbit Tibia Using Microfixed Cobalt-Chromium Membranes with Whole Blood and Platelet-Rich Plasma

    Directory of Open Access Journals (Sweden)

    Oscar A. Decco

    2015-07-01

    Full Text Available Background: Bone augmentation is a subject of intensive investigation in regenerative bone medicine and constitutes a clinical situation in which autogenous bone grafts or synthetic materials are used to aid new bone formation. Method: Based on a non-critical defect, Co-Cr barrier membranes were placed on six adult Fauve de Bourgogne rabbits, divided into two groups: whole blood and PRP. Three densitometric controls were performed during the experiment. The animals were euthanized at 30, 45, 60, and 110 days. The presence of newly formed bone was observed. Samples for histological studies were taken from the augmentation center. Results: External and internal bone tissue augmentation was observed in almost all cases. Significant differences between PRP- and whole blood–stimulated bone augmentation were not observed. At 60 days, bones with PRP presented higher angiogenesis, which may indicate more proliferation and cellular activity. Conclusion: PRP activates the bone regeneration process under optimized conditions by stimulation of osteoblast proliferation after six weeks, when a significant difference in cellular activity was observed. Membranes could stimulate bone augmentation at the site of placement and in the surrounding areas.

  3. Performance evaluation of PL-11 platelet analyzer

    Institute of Scientific and Technical Information of China (English)

    张有涛

    2013-01-01

    Objective To evaluate and report the performance of PL-11 platelet analyzer. Methods Intravenous blood sam-ples anticoagulated with EDTA-K2 and sodium citrate were tested by the PL-11 platelet analyzer to evaluate the intra-assay and interassay coefficient of variation(CV),

  4. Platelets in liver transplantation : Friend or foe?

    NARCIS (Netherlands)

    Pereboom, Ilona T. A.; Lisman, Ton; Porte, Robert J.

    2008-01-01

    Apart from the well-known role of blood platelets in hemostasis, there is emerging evidence that platelets have various nonhemostatic properties that play a critical role in inflammation, angiogenesis, tissue repair and regeneration, and ischemia/reperfusion (I/R) injury. All these processes may be

  5. Studies on megakaryopoiesis and platelet function

    NARCIS (Netherlands)

    Meinders, M.

    2015-01-01

    Platelets are blood circulating specialized subcellular fragments, which are produced by megakaryocytes. Platelets are essential for hemostasis and wound healing but also play a role in non-hemostatic processes such as the immune response or cancer metastasis. Considering the immediate precursors of

  6. Surface modification of ultrahigh molecular weight polyethylene by the poly(ethylene glycol)-grafted method and its effect on the adsorption of proteins and the adhesion of blood platelets.

    Science.gov (United States)

    Xia, Bing; Xie, Meiju; Yang, Bangcheng

    2013-01-01

    With the help of a silane coupling agent, poly(ethylene glycol) (PEG), a well-biocompatable agent, was grafted onto the surface of ultrahigh molecular weight polyethylene (UHMWPE) by ultraviolet initiation. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis proved the success of PEG grafting. Water contact angle measurement showed that the modified UHMWPE was obviously improved in surface hydrophilicity and thermogravimetric analysis result showed that its thermostability did not decline even it was pretreated by strong acids. Then, the protein adsorption of the modified UHMWPE was investigated using three model proteins including bovine serum albumin, lysozyme, and fibrinogen. Rabbit blood was used to study the platelet adhesion on the surface of modified UHMWPE. The results indicated that the quantity of protein adsorption on the modified UHMWPE grafted PEG reduced apparently for all the model proteins while there was some specific differences or exceptions among them. It was ascribed to the changed surface chemical composition, surface hydrophilicity and surface topography after modification. The adhesive ability of blood platelets on the modified surface of UHMWPE decreased after PEG grafting. Owing to the improved resistance to fibrinogen adsorption and platelet adhesion, the surface modification might endow the UHWMPE surface better anticoagulation ability according to clotting mechanism.

  7. Effects of dermatan sulfate derivatives on platelet surface P-selectin expression and protein C activity in blood of inflammatory bowel disease patients

    Institute of Scientific and Technical Information of China (English)

    Sheng-Li Ji; Hai-Yan Du; Yan-Qing Chi; Hui-Fei Cui; Ji-Chao Cao; Mei-Yu Geng; Hua-Shi Guan

    2004-01-01

    AIM: To investigate the effect of dermatan sulfate (DS)derivatives on platelet surface P-selectin expression and blood activated protein C (APC) activity in patients with inflammatory bowel disease (IBD), and to clarity the antiinflammatory mechanism of DS derivatives.METHODS: Dermatan sulfate (DS) was sulfated with chlorosulfonic acid to prepare polysulfated dermatan sulfate (PSDS). The major disaccharides of DS and PSDS were determined by 1H nuclear magnetic resonance spectroscopy (1H-NMR) and 13C-NMR. Both DS and PSDS were depolymerized with hydrogen peroxide. The fragments were separated by gel filtration chromatography. The effects of DS derivatives on P-selectin expression were assayed by ELISA method,and blood APC activity was assayed by the synthetic chromogenic substrate method.RESULTS: The major disaccharides of DS and PSDS were IdoA-1→3-GalNAc-4-SO3 and IdoA-2SO3-1→3-GalNAc4, 6-diSO3, respectively. Compared with the adenosine diphosphate stimulated group and IBD control group, DS and its derivatives all had significant inhibitory effects on P-selectin expression (P<0.01), but there was no difference between DS-derived oligosaccharides (DSOSs) and PSDS-derived oligosaccharides (PSDSOSs). The experiments on APC activity showed that DS and its derivatives all enhanced APC activity. The most active DSOS was the one with a relative molecular weight (Mr) of 4 825, which enhanced the APC activity from 106.5±11.5% to 181.8±22.3% (P<0.01). With the decrease of Mr, the activity of DSOSs decreased gradually. The effect of PSDS on APC activity enhancement was more significant than that of DS, and the APC activity was raised to 205.2±22.1% (P<0.01). All the PSDSOSs were more active than DSOSs on the basis of comparable Mr. With the decrease of Mr, the activity of PSDSOSs increased gradually, and the most active PSDSOS was PSDSOS3 with Mr of 2 749, which enhanced the APC activity to 331.2±27.8% (P<0.01), then the activity of PSDSOSs decreased gradually

  8. CFU-Mk content of immunoselected CD34+ peripheral blood progenitor cells, evaluated with an adapted serum-free methylcellulose assay, is predictive of platelet lineage reconstitution in children with solid tumors.

    Science.gov (United States)

    Boiret, N; Kanold, J; Fouassier, M; Bons, J M; Halle, P; Rapatel, C; Berger, J; Pireyre, P; Blanzat, V; Travade, P; Bonhomme, J; Demeocq, F; Berger, M G

    2000-08-01

    Immunoselected CD34+ peripheral blood progenitor cell (PBPC) transplantation is now frequently used to support autologous hematopoiesis after myeloablative therapy, its feasability having been proved by several groups. However, we and others observed delayed platelet recovery. We hypothesized that immunoselection processing might induce selective loss of megakaryocyte progenitors, or a decrease in their proliferation. We used a colony-forming units megakaryocyte (CFU-Mk) assay to evaluate these consequences and predict platelet recovery in patients. In CD34+ PBPCs from 10 children with solid tumors, we observed no selective loss in CFU-Mk numbers during immunoselection processing and no impairment of clonogenicity. The CFU-Mk yield (59.2 +/- 11.3%) was at least similar to the CD34+ yield (44.2 +/- 3.8%). We assessed the predictive value of CFU-Mk numbers infused for recovery of platelet lineage. We found an inverse correlation between the time taken to reach a platelet count greater than 50 x 10(9)/L and only the CFU-Mk dose (r = -0.71; p = 0.022) among the different type of progenitors, including colony-forming units granulocyte-macrophage (CFU-GM), burst-forming units erythrocyte (BFU-E) and colony-forming units-mixed (CFU-Mix). These findings suggest that CFU-Mk number could be used as sole predictive functional parameter for platelet reconstitution in children after immunoselection of CD34+ cells, in particular for low CD34+ cell dose, and thus as an indicator for initial quality of hematopoietic cells before in vitro expansion.

  9. Glycoprotein Ibα clustering in platelet storage and function

    NARCIS (Netherlands)

    Gitz, E.

    2013-01-01

    Platelets are anucleated, discoid-shaped cells that play an essential role in the formation of a hemostatic plug to prevent blood loss from injured vessels. Initial platelet arrest at the damaged arterial vessel wall is mediated through the interaction between the platelet receptor glycoprotein (GP)

  10. Ultrastructural studies of the gray platelet syndrome.

    Science.gov (United States)

    White, J G

    1979-05-01

    The gray platelet syndrome (GPS) is a rare inherited disorder in which peripheral blood platelets are relatively large, vacuolated, and almost devoid of cytoplasmic granulation. In the present study we have evaluated the ultrastructure and cytochemistry of platelets from 2 patients with the GPS to determine precisely which organelles are missing from their cells. The findings indicate that gray platelets contain normal numbers of mitochondria, dense bodies, peroxisomes, and lysosomes but specifically lack alpha-granules. Preliminary studies of megakaryocytes from 1 of the 2 patients suggest that the defect in granule formation may lie at the level of the Golgi zone.

  11. Platelet-TLR7 mediates host survival and platelet count during viral infection in the absence of platelet-dependent thrombosis.

    Science.gov (United States)

    Koupenova, Milka; Vitseva, Olga; MacKay, Christopher R; Beaulieu, Lea M; Benjamin, Emelia J; Mick, Eric; Kurt-Jones, Evelyn A; Ravid, Katya; Freedman, Jane E

    2014-07-31

    Viral infections have been associated with reduced platelet counts, the biological significance of which has remained elusive. Here, we show that infection with encephalomyocarditis virus (EMCV) rapidly reduces platelet count, and this response is attributed to platelet Toll-like receptor 7 (TLR7). Platelet-TLR7 stimulation mediates formation of large platelet-neutrophil aggregates, both in mouse and human blood. Intriguingly, this process results in internalization of platelet CD41-fragments by neutrophils, as assessed biochemically and visualized by microscopy, with no influence on platelet prothrombotic properties. The mechanism includes TLR7-mediated platelet granule release, translocation of P-selectin to the cell surface, and a consequent increase in platelet-neutrophil adhesion. Viral infection of platelet-depleted mice also led to increased mortality. Transfusion of wild-type, TLR7-expressing platelets into TLR7-deficient mice caused a drop in platelet count and increased survival post EMCV infection. Thus, this study identifies a new link between platelets and their response to single-stranded RNA viruses that involves activation of TLR7. Finally, platelet-TLR7 stimulation is independent of thrombosis and has implications to the host immune response and survival.

  12. Donor demographic and laboratory predictors of single donor platelet yield

    Directory of Open Access Journals (Sweden)

    R. Arun

    2013-10-01

    Full Text Available Background: Platelet transfusions are essential to prevent morbidity and mortality in patients who are severely thrombocytopenic and are at risk of spontaneous bleeding. Platelets are currently obtained either by fractionation of whole blood or by platelet apheresis. The quality of single donor platelets (SDP in terms of yield influences platelet recovery in the recipient and allows prolonging intervals between transfusions. Material and Methods: Donor demographic and laboratory data were analyzed prior to performing plateletpheresis to identify donor factors that influence platelet yield. The study was conducted on 130 healthy, first-time plateletpheresis donors over a period of 4 years. The plateletpheresis procedures were performed using Fresenius Kabi COM.TEC and Hemonetics MCS plus separator. A relationship between pre-donation donor variables and yield of platelets was studied using the Pearson correlation. Results: The mean platelet yield was 3.160.62x1011 per unit. A positive correlation was observed between platelet yield and pre-donation platelet count, body mass index (BMI; Kg/m2 of the donor, while a negative correlation was observed between age and the platelet yield. Conclusion: Donor pre-donation platelet count, BMI and donor age influence platelet yield. Young healthy donors with a high platelet count and better BMI can give a better platelet yield in the SDP.

  13. Comparative studies of the antioxidant effects of a naturally occurring resveratrol analogue -- trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and resveratrol -- against oxidation and nitration of biomolecules in blood platelets.

    Science.gov (United States)

    Olas, Beata; Wachowicz, Barbara; Nowak, Pawel; Stochmal, Anna; Oleszek, Wieslaw; Glowacki, Rafal; Bald, Edward

    2008-08-01

    The action of two phenolic compounds isolated from the bark of Yucca schidigera: trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and its analogue -- resveratrol (trans-3,4',5-trihydroxystilbene, present also in grapes and wine) on oxidative/nitrative stress induced by peroxynitrite (ONOO(-), which is strong physiological oxidant and inflammatory mediator) in human blood platelets was compared. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, significantly inhibited protein carbonylation and nitration (measured by enzyme-linked immunosorbent assay method) in the blood platelets treated with peroxynitrite (0.1 mM) and markedly reduced an oxidation of thiol groups of proteins (estimated with 5,5'-dithio-bis(2-nitro-benzoic acid)] or glutathione (measured by high performance liquid chromatography method) in these cells. The trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene, like resveratrol, also caused a distinct reduction of platelet lipid peroxidation induced by peroxynitrite. The obtained results indicate that in vitro trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene and resveratrol have very similar protective effects against peroxynitrite-induced oxidative/nitrative damage to the human platelet proteins and lipids. Moreover, trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene proved to be even more potent than resveratrol in antioxidative tests. We conclude that the novel tested phenolic compound -- trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene isolated from Y. schidigera bark possessing Generally Recognized As Safe label given by the Food and Drug Administration and allows their human dietary use -- seems to be a promising candidate for future evaluations of its antioxidative activity and may be a good candidate for scavenging peroxynitrite.

  14. Relationship between Platelet Activation Related Factors and Polymorphism of Related Genes in Patients with Coronary Heart Disease of Blood-stasis Syndrome

    Institute of Scientific and Technical Information of China (English)

    XUE Mei; CHEN Ke-ji; YIN Hui-jun

    2008-01-01

    Objective: To comparatively study the expressive conditions of platelet activation related factors (GP Ⅰ b, GP Ⅱ b-Ⅲ a and GMP-140) in healthy subjects and patients with coronary heart disease (CHD) of blood-stasis (BS) or non-blood-stasis (non-BS) syndrome, and to analyze the relationship between the activities of various glycoproteins and the polymorphism of genes. Methods: With case control design adopted, patients with the CHD (40 of BS, 37 of non-BS) and 39 healthy subjects for control, all fitting to the inclusion criteria, were selected in this study. The number of affected coronary branches was recorded by the contrast examination. The mean fluorescence intensity (MFI) of GP Ⅰ b, GP Ⅱ b-Ⅲ a, and GMP-140 (CD42b, CD61, CD62p) in patients and healthy persons was measured with flow cytometry, the polymorphism of HPA-3 gene was detected by Taqman probe technique and that of HPA-2 gene was determined by gene sequencing. Results: MFI of CD61 and CD62p was higher in the CHD patients than in the healthy control, which was also higher in patients of BS syndrome than in patients of non-BS syndrome (P0.05); at the same time, no significant difference of all the above-mentioned three MFI could be found in patients with various numbers of affected coronary branches, neither in patients with different genotypes at GP Ⅱ b HPA-3 and GP Ⅰ b HPA-2 polymorphism loci (P>0.05). Conclusion: (1) The activities of GP Ⅱ b-Ⅲ a and GMP-140 were obviously increased in the genesis and developing process of CHD and CHD of BS syndrome, and so they could be taken as one of the objective indexes for microscopic diagnosis of BS syndrome. (2) The level of GP Ⅰ b was lower in CHD patients than in healthy persons, but it was not a sensitive indicator for BS syndrome of CHD. (3) Levels of GP Ⅱ b-Ⅲ a, GP Ⅰ b and GMP-140 were not related with the number of affected coronary branches in CHD patients. (4) The changes in amino-acids expression induced by the two loci

  15. IgG platelet antibodies in EDTA-dependent pseudothrombocytopenia bind to platelet membrane glycoprotein IIb.

    Science.gov (United States)

    Fiorin, F; Steffan, A; Pradella, P; Bizzaro, N; Potenza, R; De Angelis, V

    1998-08-01

    EDTA-dependent pseudothrombocytopenia (PTCP) consists of an inappropriate low platelet count caused by autoantibodies present in the serum samples reacting with platelets only in EDTA-anticoagulated blood. By using immunoprecipitation and Western blot techniques, we studied the immunochemical specificity of platelet agglutinating autoantibodies in the serum samples of 10 patients with PTCP. Furthermore, to evaluate a possible role of PTCP-associated IgG autoantibodies in increased platelet turnover, we assayed the plasma glycocalicin (GC) level and calculated the GC index for every patient. Our results provide direct evidence that an epitope located on platelet membrane glycoprotein IIb is recognized by PTCP-associated IgG antibodies; moreover GC levels in patients with EDTA-dependent PTCP were similar to control levels, thus excluding an increased platelet turnover. We conclude that antiplatelet antibodies directed against platelet cryptantigens are unlikely to have a major role in the increased removal of cells from circulation.

  16. Laboratory testing for platelet function disorders.

    Science.gov (United States)

    Israels, S J

    2015-05-01

    Platelet function testing is both complex and labor intensive. A stepwise approach to the evaluation of patients with suspected platelet disorders will optimize the use of laboratory resources, beginning with an appropriate clinical evaluation to determine whether the bleeding is consistent with a defect of primary hemostasis. Bleeding assessment tools, evaluation of platelet counts, and review of peripheral blood cell morphology can aid the initial assessment. For patients requiring further laboratory testing, platelet aggregometry, secretion assays, and von Willebrand factor assays are the most useful next steps and will direct further specialized testing including flow cytometry, electron microscopy, and molecular diagnostics. Guidelines and recommendations for standardizing platelet function testing, with a particular focus on light transmission aggregometry, are available and can provide a template for clinical laboratories in establishing procedures that will optimize diagnosis and assure quality results. This review outlines an approach to platelet function testing and reviews testing methods available to clinical laboratories.

  17. Mean platelet volume in acute rheumatic fever.

    Science.gov (United States)

    Sert, Ahmet; Aypar, Ebru; Odabas, Dursun

    2013-01-01

    Acute rheumatic fever (ARF) is still an endemic disease, especially among school-aged children in developing countries. Mean platelet volume (MPV), which is commonly used as a measure of platelet size, indicates the rate of platelet production and platelet activation. We aimed to investigate MPV in children with ARF. The study population consisted of 40 children with ARF (32 patients with carditis and 8 patients without carditis) and 40 healthy control subjects. White blood cell (WBC) and platelet counts were significantly higher and MPV values were significantly lower in patients with ARF during the acute stage when compared to controls. Erythrocyte sedimentation rate (ESR) and C-reactive protein values significantly decreased in patients with ARF after the treatment when compared to baseline, whereas MPV values increased. MPV values were negatively correlated with ESR and WBC, and platelet counts. In conclusion, during the acute stage of ARF, MPV values were lower when compared to controls.

  18. 血小板聚集影响因素在血细胞计数中的临床应用%Clinical application of platelet aggregation for white blood cell count

    Institute of Scientific and Technical Information of China (English)

    胡恩亮; 赵媛; 王妍; 樊爱琳; 郑善銮

    2016-01-01

    Objective To analyze the cause of platelet aggregation in blood specimens ,so as to provide basis for reducing platelet aggregation ,and avoiding false positive of platelet count ,false report ,misdiagnosis and mistreatment .Methods The blood speci-mens which platelet was below 80 × 109 /L ,below 125 × 109 /L with histogram hinted platelet aggregation ,were smeared ,stained with Wright-Giemsa ,and observed by microscope for platelet morphological changes .The data between each groups were calculated and analyzed by statistical software SPSS version 18 .0 .Results A total of 184 cases of ethylenediaminetetraacetic acid dependent pseudothrombocytopenia(EDTA-PTCP) were found ,accounted for 0 .444 ‰ totally ,including 0 .244 ‰ of out-patients (101 cases) , 0 .159 ‰ of hospitalized patients (66 cases) ,and 0 .041 ‰ of health examination personnel (17 cases) .3 cases of multi-dependent pseudothrombocytopenia and 25 cases of pseudo platelet aggregation were found ,and accounted for 0 .007 ‰ and 0 .060 ‰ respec-tively .Conclusion The discovery of platelet aggregation which caused mainly by EDTA-PTCP ,still relies on microscopy ,and pseu-do platelet aggregation comes mainly from sampling ,so it needs to strengthen the skills training .%目的:分析血小板聚集影响因素,为降低血小板聚集所致血小板假性减低、实验室规避报告风险及减低误诊误治提供依据。方法对血小板小于80×109/L 、小于125×109/L 合并直方图提示血小板凝集标本进行推片、瑞氏-吉姆萨染色后显微镜下观察是否聚集,并采用统计软件 SPSS 18.0进行统计分析。结果乙二胺四乙酸依赖性血小板减少症(EDTA-PTCP)共计184例,占0.444‰,其中门诊患者101例,占0.244‰,住院患者66例,占0.159‰,体检者17例,占0.041‰;多重抗凝剂依赖性血小板假性减少共计3例,占0.007‰,假性血小板聚集共计25例,占0.060‰。结论血小

  19. The effect of centrifugation speed and time on pre-analytical platelet activation

    DEFF Research Database (Denmark)

    Söderström, Anna Cecilia; Nybo, Mads; Nielsen, Christian

    2016-01-01

    . METHODS: Citrate- and EDTA-anticoagulated blood from healthy volunteers were centrifuged at 80-10,000 g for 5-15 min to prepare plasma and platelet-rich plasma. Pre-analytical platelet activation was assessed by flow cytometric measurement of platelet P-selectin (CD62p) expression. Blood cell counts, mean...... platelet volume (MPV), immature platelet fraction (IPF), and platelet distribution width (PDW) were measured. Platelet aggregation in platelet-rich plasma induced by arachidonic acid (AA), ADP or thrombin receptor activator peptide-6 (TRAP) was tested by 96-well aggregometry. RESULTS: The median percentage...... of platelets expressing P-selectin in citrate- and EDTA-plasma centrifuged at 2000 g for 10 min were 43% [interquartile range (IQR), 38%-53%] and 56% (IQR, 31%-78%), respectively (p=0.82). Platelet-rich plasma prepared at 100-250 g for 10 min had significantly lower platelet P-selectin expression (11%-15%), p...

  20. Platelet Lysates Produced from Expired Platelet Concentrates Support Growth and Osteogenic Differentiation of Mesenchymal Stem Cells

    OpenAIRE

    Sandra Mjoll Jonsdottir-Buch; Ramona Lieder; Olafur Eysteinn Sigurjonsson

    2013-01-01

    BACKGROUND: Mesenchymal stem cells are promising candidates in regenerative cell therapy. Conventional culture methods involve the use of animal substances, specifically fetal bovine serum as growth supplement. Since the use of animal-derived products is undesirable for human applications, platelet lysates produced from human platelets are an attractive alternative. This is especially true if platelet lysates from already approved transfusion units at blood banks can be utilized. The purpose ...

  1. The Role of Inflammation in Regulating Platelet Production and Function: Toll-like Receptors in Platelets and Megakaryocytes

    OpenAIRE

    Beaulieu, Lea M.; Freedman, Jane E.

    2009-01-01

    Platelets have been extensively studied as hemostatic regulators, stopping uncontrolled flow of blood from an injured vessel and allowing for repair. However, multiple studies have shown that platelets can interact with bacterial proteins, particularly seen during sepsis and inflammation. Immune cells recognize pathogens through Toll-like Receptors (TLRs). These same receptors allow platelets to recognize bacterial proteins and regulate platelet immunity and function. This review examines the...

  2. Thrombopoietin induces p-selectin expression on platelets and subsequent platelet/leukocyte interactions.

    Science.gov (United States)

    Tibbles, Heather E; Navara, Christopher S; Hupke, Michael A; Vassilev, Alexei O; Uckun, Fatih M

    2002-04-12

    Ligation of thrombopoietin (TPO) to the platelet c-Mpl receptor induces numerous biochemical pathways in the absence of aggregation. Two forms of recombinant TPO are currently in clinical trials for the treatment of thrombocytopenia. This study focuses on the effects of the full-length recombinant human TPO (rhTPO) on platelets in a whole blood system. Platelet-leukocyte associations (PLAs) were visualized following rhTPO stimulation as CD42b/CD 45 double positive clusters by FACS analysis. Treatment of washed platelets with rhTPO induced granule release and expression of the leukocyte adhesion receptor P-selectin (CD 62P) in the absence of aggregation and calcium mobilization. RhTPO also induced platelet-leukocyte interactions in whole blood. Following stimulation, leukocytes were recruited by platelets through P-selectin in a calcium-dependent manner. rhTPO stimulates platelet-leukocyte associations in whole blood through expression of platelet P-selectin. To our knowledge, this is the first report that identifies TPO as a promoter of platelet-leukocyte interactions.

  3. Functional platelet defects in children with severe chronic ITP as tested with 2 novel assays applicable for low platelet counts.

    Science.gov (United States)

    van Bladel, Esther R; Laarhoven, Annemieke G; van der Heijden, Laila B; Heitink-Pollé, Katja M; Porcelijn, Leendert; van der Schoot, C Ellen; de Haas, Masja; Roest, Mark; Vidarsson, Gestur; de Groot, Philip G; Bruin, Marrie C A

    2014-03-06

    Immune thrombocytopenia (ITP) is an autoimmune disease with a complex heterogeneous pathogenesis and a bleeding phenotype that is not necessarily correlated to platelet count. In this study, the platelet function was assessed in a well-defined cohort of 33 pediatric chronic ITP patients. Because regular platelet function test cannot be performed in patients with low platelet counts, 2 new assays were developed to determine platelet function: first, the microaggregation test, measuring in platelets isolated from 10 mL of whole blood the platelet potential to form microaggregates in response to an agonist; second, the platelet reactivity assay, measuring platelet reactivity to adenosine diphosphate (ADP), convulxin (CVX), and thrombin receptor activator peptide in only 150 μL of unprocessed whole blood. Patients with a severe bleeding phenotype demonstrated a decreased aggregation potential upon phorbol myristate acetate stimulation, decreased platelet degranulation following ADP stimulation, and a higher concentration of ADP and CVX needed to activate the glycoprotein IIbIIIa complex compared with patients with a mild bleeding phenotype. In conclusion, here we have established 2 functional tests that allow for evaluation of platelet function in patients with extremely low platelet counts (platelet function is related to bleeding phenotype in chronic ITP.

  4. Platelet Function Tests

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Platelet Function Tests Share this page: Was this page helpful? ... their patients by ordering one or more platelet function tests. Platelet function testing may include one or more of ...

  5. Congenital platelet function defects

    Science.gov (United States)

    ... storage pool disorder; Glanzmann's thrombasthenia; Bernard-Soulier syndrome; Platelet function defects - congenital ... Congenital platelet function defects are bleeding disorders that ... function, even though there are normal platelet numbers. Most ...

  6. Stability of lyophilized human platelets loaded with small molecule carbohydrates.

    Science.gov (United States)

    Wang, J X; Yang, C; Wan, W; Liu, M X; Ren, S P; Quan, G B; Han, Y

    2011-01-01

    Long-term preservation of platelets is a great challenge for blood transfusion centers, due to the required narrow storage temperature arange (22 ± 2 degree C). Short shelf life and potential bacterial growth often lead to the shortage of high-quality platelets. Freeze-dried preservation is thus believed to be a potential solution for long-term platelet storage without losing the hemostasis function. Here we report a new platelet preservation method, which uses small molecule carbohydrates to extend storage time and to maintain platelet function. The activities of lyophilized platelets that were stabilized with small molecule carbohydrate (e.g., cell viability, mean platelet volume, activation characteristics, and aggregation kinetics) were maintained after storage of 30, 60, and 90 days at room temperature, 4 degree C, and -20 degree C. The recovery of freeze-dried platelets was 87 percent in comparison to fresh platelets. The mean platelet volume of rehydrated platelets increased (from 6.8 fl to 8.0 fl). About 40 percent of rehydrated platelets was in the early-activated stage (PCA-1 positive) and 30 percent was in the terminal-activated stage (CD62P positive). The cell viability was about 60 percent as measured with CMFDA vital probes. The aggregation rate of rehydrated platelets after 90-day storage was similar to fresh platelets stored at 22 degree C ± 2 degree C.

  7. Platelets and erythrocyte-bound platelets bind infectious HIV-1 in plasma of chronically infected patients.

    Science.gov (United States)

    Beck, Zoltan; Jagodzinski, Linda L; Eller, Michael A; Thelian, Doris; Matyas, Gary R; Kunz, Anjali N; Alving, Carl R

    2013-01-01

    Chronic HIV-1 infection is associated with persistent viremia in most patients, but it remains unclear how free virus may survive the potential hostile effects of plasma. We investigated whether sites might exist on the surfaces of circulating blood cells for protection of infectious HIV-1 particles. Red blood cells (RBC) either from blood of uninfected normal individuals, or from blood obtained without EDTA from chronically infected HIV-1 patients, invariably contained a small number of RBC having attached platelets as determined by flow cytometry, light microscopy, and immunofluorescence microscopy. After mixing normal RBC with platelet-rich plasma, discrete populations of RBC, platelets, and complexes of platelets attached to RBC were purified by fluorescence-activated cell sorting. Upon incubation of purified cells or platelets with HIV-1 followed by washing and co-incubation with CD4-positive peripheral blood mononuclear cells (PBMC), platelets, and platelet-RBC complexes, but not platelet-free RBC, caused infection of PBMC. Infection was prevented by pre-treating the platelet-RBC complexes with EDTA. Plasma and RBC (comprising a RBC/platelet-RBC mixture) from chronically infected patients with low viral loads were also co-incubated with PBMC ex vivo to determine the presence of infectious HIV-1. All freshly isolated plasmas from the HIV-1-infected donors, obtained in the absence of anticoagulant, were noninfectious. Interestingly, the RBC from most of the patients caused cell-cell infection of PBMC that was prevented by stripping the RBC with EDTA. A monoclonal antibody to DC-SIGN partially inhibited cell-cell HIV-1 infection of PBMC by normal RBC pre-incubated with platelets and HIV-1. We conclude: (a) platelet-free EDTA-free plasma from chronically infected HIV-1 patients, although containing viral RNA, is an environment that lacks detectable infectious HIV-1; (b) platelets and platelet-RBC complexes, but not purified RBC, bind infectious HIV-1; (c) DC

  8. Platelets and erythrocyte-bound platelets bind infectious HIV-1 in plasma of chronically infected patients.

    Directory of Open Access Journals (Sweden)

    Zoltan Beck

    Full Text Available Chronic HIV-1 infection is associated with persistent viremia in most patients, but it remains unclear how free virus may survive the potential hostile effects of plasma. We investigated whether sites might exist on the surfaces of circulating blood cells for protection of infectious HIV-1 particles. Red blood cells (RBC either from blood of uninfected normal individuals, or from blood obtained without EDTA from chronically infected HIV-1 patients, invariably contained a small number of RBC having attached platelets as determined by flow cytometry, light microscopy, and immunofluorescence microscopy. After mixing normal RBC with platelet-rich plasma, discrete populations of RBC, platelets, and complexes of platelets attached to RBC were purified by fluorescence-activated cell sorting. Upon incubation of purified cells or platelets with HIV-1 followed by washing and co-incubation with CD4-positive peripheral blood mononuclear cells (PBMC, platelets, and platelet-RBC complexes, but not platelet-free RBC, caused infection of PBMC. Infection was prevented by pre-treating the platelet-RBC complexes with EDTA. Plasma and RBC (comprising a RBC/platelet-RBC mixture from chronically infected patients with low viral loads were also co-incubated with PBMC ex vivo to determine the presence of infectious HIV-1. All freshly isolated plasmas from the HIV-1-infected donors, obtained in the absence of anticoagulant, were noninfectious. Interestingly, the RBC from most of the patients caused cell-cell infection of PBMC that was prevented by stripping the RBC with EDTA. A monoclonal antibody to DC-SIGN partially inhibited cell-cell HIV-1 infection of PBMC by normal RBC pre-incubated with platelets and HIV-1. We conclude: (a platelet-free EDTA-free plasma from chronically infected HIV-1 patients, although containing viral RNA, is an environment that lacks detectable infectious HIV-1; (b platelets and platelet-RBC complexes, but not purified RBC, bind infectious HIV

  9. Analysis of Red Blood Cell Spill over in Platelet Apheresis Collection%机采血小板红细胞混入量超标原因分析

    Institute of Scientific and Technical Information of China (English)

    侯晓岩; 张轶

    2012-01-01

    Objective Proper process controls should be applied to decrease percentage of red blood cell spill over, to avoid loss of platelet products, and to maintain a high quality of platelet apheresis collection. Methods Using a statistical method to analyze 33 cases of red cell spill over tested out of the total 18019 platelet apheresis products in Taiyuan Blood Center from 2005 to 2009. Results Red cell spill over is related to the process of platelet apheresis collection and the maintenance condition of relevant machine. Conclusion Good pre-screening based on practical experience as a first pass, excellent technical operation to ensure whole collection process and careful maintenance of apheresis machine could help minimize the chance of red cell spill over and guarantee the effectiveness of platelets product.%目的 在机采血小板采集工作中采取相应措施,减少产品冲红几率,避免制品在二次分离出红细胞的同时丢失血小板,确保机采血小板的质量.方法 通过对2005 ~ 2009年太原血液中心机采血小板18019人次中33例红细胞混入量超标的原因经统计学处理进行分析.结果 献血者的筛选、操作人员技术的熟练程度、仪器设备是否处于良好的运行状态与血小板制品的冲红有关.结论 根据实际工作经验力争在献血者筛选上把好第一关,在仪器设备的维护保养上做到细致到位,在工作人员操作技术上做到精益求精,将血小板制品冲红几率降到最低,确保机采血小板的有效成分.

  10. [A case of pseudothrombocytopenia due to platelet cold agglutinins].

    Science.gov (United States)

    Hayashi, Satoru; Nishiyama, Miho; Jouzaki, Kiyoshi; Tomiyama, Yoshiaki; Kurata, Yoshiyuki

    2005-08-01

    We report a case of pseudothrombocytopenia due to platelet cold agglutinins. Platelet counts were decreased in blood drawn in a tube without anti-coagulant just after withdrawal as well as in blood drawn in a tube with anti-coagulant, such as EDTA-2K, MgSO4, citrate or heparin. In our case, platelet aggregates were noted on blood-smear made from blood samples obtained with and without anti-coagulant. RBC and WBC counts were within the normal range. Platelet aggregates mainly consisted of 2-5 platelets. Patient plasma agglutinated normal platelets at a temperature below 10 degrees C. Immunoglobulin class was determined as IgM by flow cytometry.

  11. Platelet lysates produced from expired platelet concentrates support growth and osteogenic differentiation of mesenchymal stem cells.

    Directory of Open Access Journals (Sweden)

    Sandra Mjoll Jonsdottir-Buch

    Full Text Available BACKGROUND: Mesenchymal stem cells are promising candidates in regenerative cell therapy. Conventional culture methods involve the use of animal substances, specifically fetal bovine serum as growth supplement. Since the use of animal-derived products is undesirable for human applications, platelet lysates produced from human platelets are an attractive alternative. This is especially true if platelet lysates from already approved transfusion units at blood banks can be utilized. The purpose of this study was to produce human platelet lysates from expired, blood bank-approved platelet concentrates and evaluate their use as growth supplement in the culture of mesenchymal stem cells. METHODOLOGY/PRINCIPAL FINDINGS: In this study, bone marrow-derived mesenchymal stem cells were cultured with one of three culture supplements; fetal bovine serum, lysates from freshly prepared human platelet concentrates, or lysates from expired human platelet concentrates. The effects of these platelet-derived culture supplements on basic mesenchymal stem cell characteristics were evaluated. All cultures maintained the typical mesenchymal stem cell surface marker expression, trilineage differentiation potential, and the ability to suppress in vitro immune responses. However, mesenchymal stem cells supplemented with platelet lysates proliferated faster than traditionally cultured cells and increased the expression of the osteogenic marker gene RUNX-2; yet no difference between the use of fresh and expired platelet concentrates was observed. CONCLUSION/SIGNIFICANCE: Our findings suggest that human platelet lysates produced from expired platelet concentrates can be used as an alternative to fetal bovine serum for mesenchymal stem cell culture to the same extent as lysates from fresh platelets.

  12. Effect of polytetrafluoroethylene artificial blood vessels on platelet aggregation and its cytocompatibility%聚四氟乙烯人工血管对血小板聚集的影响及细胞相容性

    Institute of Scientific and Technical Information of China (English)

    姜正明; 陈魁; 胡彩娜

    2016-01-01

    背景:聚四氟乙烯人工血管是临床常用的医用材料,但其具体的基础研究内容尚未完善。目的:观察聚四氟乙烯人工血管对血小板聚集的作用及细胞相容性。方法:①对血小板聚集的作用:检测聚四氟乙烯人工血管的凝血时间、复钙时间。将生理盐水、蒸馏水及聚四氟乙烯人工血管分别加入兔红细胞悬液中,计算溶血率;②细胞生物相容性:将SD大鼠原代心肌细胞分别接种于普通玻璃爬片与聚四氟乙烯人工血管片上,3 d后,检测细胞乳酸脱氢酶释放;5 d后,检测细胞增殖。结果与结论:①聚四氟乙烯人工血管对兔血的动态凝血时间、复钙时间没有影响;聚四氟乙烯人工血管的溶血率为2.3%;②与接种于普通玻璃爬片上的心肌细胞相比,接种于聚四氟乙烯人工血管片上的心肌细胞增殖及乳酸脱氢酶释放无明显变化;③结果表明,聚四氟乙烯人工血管血小板聚集无影响,具有良好的血液相容性与细胞相容性。%BACKGROUND:Polytetrafluoroethylene artificial blood vessels have been extensively used in clinic. However, there is stil a lack of basic study on it. OBJECTIVE:To observe the effect of polytetrafluoroethylene artificial blood vessels on platelet aggregation and its cytocompatibility. METHODS:Effect on platelet aggregation:Dynamic platelet clotting time and plasma recalcification time were detected. Normal saline, distil ed water and polytetrafluoroethylene artificial blood vessels were added into the rabbit red cel suspensions, respectively, to count the hemolysis ratio. Cytocompatibility:Primary myocardial cel s from Sprague-Dawley rats were respectively seeded onto the common round coverslip and polytetrafluoroethylene artificial blood vessels, and the lactate deshydrogenase release and cel proliferation were detected at 3 and 5 days, respectively. RESULTS AND CONCLUSION:Polytetrafluoroethylene artificial

  13. The Percentage Variation of Platelets in Multiple Donator Apheresis Platelets in Peripheral Blood Reticulocytes%多次单采血小板献血者外周血网织血小板百分比水平的变化

    Institute of Scientific and Technical Information of China (English)

    周爱国; 李继红; 周宁; 孟德伍; 祝峰; 范恩勇

    2016-01-01

    目的:了解单采血小板献血者外周血网织血小板百分比水平的变化情况。方法按照单采血小板捐献情况分为2组,实验组为参加过单采血小板的献血者153例,对照组为以往无献血史,首次来血站献血且符合献血条件,共189例,利用全自动血球分析仪检测WBC、RBC、Hb、HCT、PLT、PDW、PCT、MPV及IPF比例等项目。结果与对照组相比,实验组中男性献血者WBC、PCT的差异均无统计学意义(P>0.05),RBC、Hb、HCT、PLT明显升高,有统计学意义(P<0.05),PDW、MPV、IPF下降,有统计学意义(P<0.05);实验组中女性献血者WBC、RBC、Hb、HCT、PLT、PCT、MPV的差异均无统计学意义(P>0.05),PDW、IPF明显升高,有统计学意义(P<0.05)。结论多次进行单采血小板捐献,对于男性献血者除加快RBC、PLT的骨髓造血功能外,并未加速IPF上升,相反促进PLT成熟。对于女性献血者则由于自身早期的生理性周期性失血,女性献血者的RBC、PLT等指标已受自身免疫负反馈调节而耐受,但对于多次捐献血小板的女性献血者,可能血小板生成能力较男性献血小板者增加有关。%Objective To understand reticulated platelet level changes in apheresis platelet donors. Methods The platelets donators were divided into experimental group (A) and control group(B). Group A comprised 153 cases of apheresis platelet donors and group B included 189 cases without the experience of blood donation. Automated blood analyzer was used for testing WBC,RBC,Hb,HCT,PLT,PDW,PCT,MPV and IPF proportions and other items. Results No significant difference was seen of WBC and PCT(P>0.05) in the male blood donors in Group A,whereas RBC,Hb,HCT,and PLT were obviously elavated(P0.05)whereas PDW and IPF were significantly increased(P<0.05). Conclusion Repeated apheresis platelet donations may accelerate RBC and PLT rather than IPF production in bone marrow

  14. Erythrocyte-platelet interaction in uncomplicated pregnancy.

    Science.gov (United States)

    Swanepoel, Albe C; Pretorius, Etheresia

    2014-12-01

    Maternal and fetal requirements during uncomplicated pregnancy are associated with changes in the hematopoietic system. Platelets and erythrocytes [red blood cells (RBCs)], and especially their membranes, are involved in coagulation, and their interactions may provide reasons for the changed hematopoietic system during uncomplicated pregnancy. We review literature regarding RBC and platelet membrane structure and interactions during hypercoagulability and hormonal changes. We then study interactions between RBCs and platelets in uncomplicated pregnancy, as their interactions may be one of the reasons for increased hypercoagulability during uncomplicated pregnancy. Scanning electron microscopy was used to study whole blood smears from 90 pregnant females in different phases of pregnancy. Pregnancy-specific interaction was seen between RBCs and platelets. Typically, one or more platelets interacted through platelet spreading and pseudopodia formation with a single RBC. However, multiple interactions with RBCs were also shown for a single platelet. Specific RBC-platelet interaction seen during uncomplicated pregnancy may be caused by increased estrogen and/or increased fibrinogen concentrations. This interaction may contribute to the hypercoagulable state associated with healthy and uncomplicated pregnancy and may also play a fundamental role in gestational thrombocytopenia.

  15. Pooled platelet concentrates: an alternative to single donor apheresis platelets?

    Science.gov (United States)

    Pietersz, R N I

    2009-10-01

    Three types of platelet concentrates (PC) are compared: PC either processed with the platelet-rich plasma (PRP) or the Buffy coat (BC) method from whole blood units and PC obtained by apheresis. Leuko-reduction (LR) pre-storage is advocated to improve quality of the PC during storage and reduce adverse reactions in recipients. Standardization of methods allow preparation of PC with comparable yields of approximately 400 x 10(9) platelets in pooled non-LR-PRP, approximately 370 x 10(9) in pooled LR-BC-PC and in LR apheresis PC the number of platelets can be targeted on 350 x 10(9) or more with devices of various manufacturers. While viral transmission can be prevented by outstanding laboratory tests, the risk of bacterial contamination should be reduced by improved arm disinfection, deviation of the first 20-30 ml of blood and culture or rapid detection assays of the PC pre-issue. In a large prospective multicenter trial no significant difference was observed between cultures of apheresis PC (n = 15,198): 0.09% confirmed positive units versus 0.06% in pooled BC-PC (n = 37,045), respectively. Though platelet activation as measured by CD62 expression may differ in vitro in PC obtained with various apheresis equipment, and also between PC processed with the two whole blood methods there is scarce literature about the clinical impact of these findings. In conclusion the final products of LR-PC derived from whole blood or obtained by apheresis can be comparable, provided the critical steps of the processing method are identified and covered and the process is in control.

  16. The causes and coping manners in the blood donation reaction of the apheresis platelet%机采血小板献血反应的原因分析与对策

    Institute of Scientific and Technical Information of China (English)

    林菊; 桑列勇; 杜冬芬; 李素娥

    2016-01-01

    Objective To investigate the causes and the treatments in the blood donation reaction of the apheresis platelet. Methods The intervention and nursing measures of 9 903 cases of apheresis platelet donors from January 2012 to November 2015 were summarized. A total of 53 blood donation responders′ data such as gender were collected, and the data were analyzed. Results From January 2012 to November 2015 blood donation reaction rate was 0.54% (53/903), which was lower than that reported in the literature. Among them, 41 cases were female and 12 were male, female blood donation reaction rate was higher than the male (χ2=78.36,P0.05). Blood donation reactions occurred in 34 cases within 5 minutes before the end of the program, accounting for 64.2%(34/53) of the total. Conclusions The sex and blood cell separator and coping of blood volume and the spiritual factors are related to blood donation reaction. Providing quality nursing and services, and creating a good environment for blood donors are conducive to prevent and reduce the occurrence of blood donation reaction.%目的:探讨机采血小板献血反应的发生原因及对策。方法总结2012年1月至2015年11月9903人次机采血小板献血者的干预及护理方法,收集53人次献血反应者性别等资料进行统计分析。结果2012年1月至2015年11月献血反应发生率为0.54%(53/9903);其中男12人次,女41人次,女性献血反应发生率高于男性(χ2=78.36,P0.05)。程序运行结束前5 min内发生献血反应34人次占64.2%。结论献血反应与性别、分离机型、处理血量、精神因素等有关,为献血者提供优质护理和服务,创造良好的献血环境,有利于预防和减少献血反应的发生。

  17. Investigation of the thrombin-generating capacity, evaluated by thrombogram, and clot formation evaluated by thrombelastography of platelets stored in the blood bank for up to 7 days

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Svendsen, M.S.; Salado, J.

    2008-01-01

    , in part, depend on its reflection of the dynamics of thrombin generation. MATERIAL AND METHODS: The kinetics of thrombin generation of platelets stored for 2 and 7 days, respectively, was assessed by calibrated automated thrombogram (CAT) and the lag time (min), time to peak (ttPeak; min), peak (nm...

  18. Roll, adhere, spread and contract: structural mechanics of platelet function.

    Science.gov (United States)

    Sorrentino, Simona; Studt, Jan-Dirk; Medalia, Ohad; Tanuj Sapra, K

    2015-01-01

    Platelets are involved in life-sustaining processes such as hemostasis, wound healing, atherothrombosis and angiogenesis. Mechanical trauma to blood vessels causes platelet activation resulting in their adherence and clot formation at the damaged site, culminating in clot retraction and tissue repair. Two of the major players underlying this process are the cytoskeleton, i.e., actin and microtubules, and the membrane integrin receptors. Rare congenital bleeding disorders such as Glanzmann thrombasthenia and Bernard-Soulier syndrome are associated with genetic alterations of platelet surface receptors, also affecting the platelet cytoskeletal structure. In this review, we summarize the current knowledge about platelet structure and adhesion, and delve into the mechanical aspects of platelet function. Platelets lack a nucleus, and can thus provide a minimal model of a biological cell. New biophysical tools may help to scrutinize platelets anew and to extend the existing knowledge on cell biology.

  19. The prowess of platelets in immunity and inflammation.

    Science.gov (United States)

    Koenen, Rory R

    2016-09-27

    Platelets not only serve as essential haemostatic cells, they also have important roles in immune defence and inflammation. Despite not having a nucleus, platelets contain physiologically relevant amounts of RNA, which can be spliced and translated into functional proteins. In addition, platelets have the ability to bind to numerous other cells, such as leukocytes and vascular cells. During those interactions, platelets can modulate cellular responses, resulting in e. g. inflammatory activation or apoptosis. Recent studies have demonstrated that platelets can influence the outcomes of bacterial and viral infection, as well as the extent of tissue injury after ischaemia. Platelets also carry considerable amounts of cytokines and growth factors in their secretory granules, preformed for rapid secretion. Those properties in combination with the sheer amount of platelets circulating in the blood stream make them an important force in the immune response during health and disease. In this overview, recent findings concerning those interesting properties of platelets beyond haemostasis are discussed.

  20. The Role of Platelets in Cardiovascular Disease: Molecular Mechanisms.

    Science.gov (United States)

    Papapanagiotou, Angeliki; Daskalakis, Georgios; Siasos, Gerasimos; Gargalionis, Antonios; Papavassiliou, Athanasios G

    2016-01-01

    The role of platelets in atherosclerotic process and subsequently in the pathophysiology of cardiovascular disease is essential as platelets in addition to their contribution to thrombosis and hemostasis modulating inflammatory reactions and immune response. Platelets after adhesion on the injured vascular endothelium and activation release a wide range of molecules stored in platelets granules such as chemokines, proinflammatory molecules and other biological response modulators accelerating interaction among platelets, endothelial cells and leukocytes. These interactions establish a localized inflammatory response that promotes the atherosclerotic process. Moreover, activated platelets give rise to microparticles another active participant within the blood stream. The purpose of this review is to present the role of platelets in the above mechanisms giving an emphasis on the nature of the platelet derived- molecules and their contribution to the atherosclerotic process.

  1. Insights into Platelet Storage and the Need for Multiple Approaches.

    Science.gov (United States)

    Handigund, Mallikarjun; Cho, Yong Gon

    2015-01-01

    Upon accidental injury and the treatment of many diseases, patients may need a transfusion of blood components in order to achieve hemostasis. Platelets are small enucleated cells derived from bone marrow megakaryocytes that undergo change upon activation at sites of vascular injury and play a vital role in vascular repair and antimicrobial host defense, collectively contributing to hemostasis. They are the common blood components transfused whenever there is need, but supplies do not equal the demand as platelets are required in many medical and surgical procedures. In addition, surplus supplies of platelet concentrate are often discarded as they have a short shelf life. Currently, platelet concentrates are stored at room temperature for a maximum of 5 days from the date of collection; the temporal aspect is an added hurdle in the growing demand for platelet concentrates. Many investigations have been carried out in attempt to improve the quality and lengthen the shelf life of platelets, but the few that have succeeded are not commercially viable. Moreover, currently there is a declining trend in platelet research, quelling the hope of platelet storage improvement. Successful strategies would be a boon for medicine in particular and humanity in general. This review deals with past and current efforts toward improving the quality of platelet concentrates by reducing platelet storage lesions and increasing the viable storage period for platelets. Also presented are new perspectives based on past and current efforts, which should be investigated for platelet research in this decade.

  2. A Multicenter study on preparation of Leukodepleted Platelet Concentrates from Pooled whole blood-derived platelets%全血制备浓缩血小板的汇集及滤除白细胞的多中心研究

    Institute of Scientific and Technical Information of China (English)

    王红; 吴瑕; 钟锐; 贺曾; 曹晔; 何语良; 陈洁; 刘嘉馨

    2012-01-01

    Objective To cooperate with a number of blood centers and evaluate the quality of pooled platelet and leukocyte depletion, which aims to supply basis for establishing operating procedures and quality standard of pooled platelet and leukocyte depletion. Methods PCs was prepared from 400 ml fresh whole blood by platelet-rich plasma (PRP) or buffy-coat (BC) method. 10 to 16 units of ABO-matched PCs were pooled, and then filtered with two types of domestic filters (namely group A and B) randomly. The conventional and functional indicators of platelet were evaluated before and after filtering, and the total samples were 202. Results The total of cases that number of platelet was more than 2. 4 × 1011 was 147, including 77 cases in group A and 70 cases in group B. In group A the number of platelet and leukocyte before and after filtering were (2. 90 ±0.45) xlO" 75(2.60±0.43) × 1011 ,(176.45 ±135.67) × 106 VS( 1.00 ±2.29) ×106 respectively ,and in group B the number of platelet and leukocyte before and after filtering were(2. 80 ±0. 36) × 1011 VS(2. 40 ± 0.37) × 1011, (175. 76 ±147. 84) × 106 VS(0. 30 ±0. 72) × 106 respectively. While the total of cases that number of platelet was less than 2. 4 × 1011 was 55, including 29 cases in group A and 26 cases in group B. In group A the number of platelet and leukocyte before and after filtering were (1. 71 ±0.39)×1011 VS( 1.43 ±0.42) × 1011 ,(65. 85 ±110. 97) ×106 VS (3. 7 ±3. 98) × 106 respectively,and in group B the number of platelet and leukocyte before and after filtering were(l. 79 ±0.48) ×1011 VS(1.42±0.46) × 1011 ,(70. 63 ±145. 55) × 106 VS(1. 45 ±2. 66) × 106 respectively. There were no significant difference(P>0. 05) of these indicators such as pH value,hypotonic shock response (HSR) ,CD62p expression ( % ) and platelet aggregation after filtering in group A and B. Conclusion Pooling and filtering platelet concentrates prepared by PRP and BC method can remove leukocyte effectively and

  3. Modified expression of surface glyconjugates in stored human platelets

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, A.; Ganguly, P.

    1987-05-01

    Platelets are anucleated cells which play an important part in blood coagulation and thrombosis. These cells may be stored in the blood bank for only 4/5 days. In order to improve the storage of platelets, it is essential to first understand the changes in these cells due to storage. In this work, human platelets were stored in autologous plasma at 4/sup 0/ or 22/sup 0/ and their surface changes were monitored with three lectins - wheat germ afflutinin (WGA), concanavalin A (Con A) and lentil lectin (LL). Blood was drawn from healthy donors and platelet rich plasma (PRP) was collected by slow speed centrifugation. Platelets stored at either temperature for different times showed increased sensitivity to agglutination by WGA after 34-48 hrs. Lectins, Con A and LL, which were not agglutinating to fresh platelets readily caused agglutination after 48-72 hrs. The platelets stored for 25 hrs or longer period were insensitive to thrombin but showed enhanced aggregation with WGA. Labelling of surface glycoconjugates of stored platelets with /sup 3/H-boro-hydride revealed progressive loss of a glycoprotein of Mr 150,000 (GPIb infinity) together with the appearance of components of Mr 69,000; Mr 60,000; Mr 25,000. New high molecular weight glycoproteins were also detected only in stored platelets. The author studies clearly indicate that modification or altered expression of platelets surface glycoproteins may be one factor of storage related dysfunction of platelets.

  4. Multiwavelength UV/visible spectroscopy for the quantitative investigation of platelet quality

    Science.gov (United States)

    Mattley, Yvette D.; Leparc, German F.; Potter, Robert L.; Garcia-Rubio, Luis H.

    1998-04-01

    The quality of platelets transfused is vital to the effectiveness of the transfusion. Freshly prepared, discoid platelets are the most effective treatment for preventing spontaneous hemorrhage or for stopping an abnormal bleeding event. Current methodology for the routine testing of platelet quality involves random pH testing of platelet rich plasma and visual inspection of platelet rich plasma for a swirling pattern indicative of the discoid shape of the cells. The drawback to these methods is that they do not provide a quantitative and objective assay for platelet functionality that can be used on each platelet unit prior to transfusion. As part of a larger project aimed at characterizing whole blood and blood components with multiwavelength UV/vis spectroscopy, isolated platelets and platelet in platelet rich plasma have been investigated. Models based on Mie theory have been developed which allow for the extraction of quantitative information on platelet size, number and quality from multi-wavelength UV/vis spectra. These models have been used to quantify changes in platelet rich plasma during storage. The overall goal of this work is to develop a simple, rapid quantitative assay for platelet quality that can be used prior to platelet transfusion to ensure the effectiveness of the treatment. As a result of this work, the optical properties for isolated platelets, platelet rich plasma and leukodepleted platelet rich plasma have been determined.

  5. Decrease in platelet activating factor stimulated phosphoinositide turnover during storage of human platelets in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Carter, M.G.; Shukla, S.D. (Univ. of Missouri School of Medicine, Columbia (USA))

    1987-05-01

    Human platelet concentrate from the American Red Cross Blood Center was stored at 24{degree}C in a shaker and aliquots were taken out at time intervals aseptically. Platelet activating factor (PAF) stimulated turnover of phosphoinositide (PPI) was monitored by assaying {sup 32}P incorporation into phosphoinositides using platelet rich plasma (PRP). Platelets in PRP were incubated with 1 {times} 10{sup {minus}7} M PAF at 37{degree}C with gentle shaking and after 5 min their lipids were extracted and analysed by TLC for {sup 32}P-phosphoinositides. The percent stimulation of {sup 32}P incorporation by PAF (over control) into PPI was approximately 250, 100, 60, 25 and 20 on days 1, 2, 3, 5 and 6, respectively. This indicated a dramatic decrease in PAF responsive turnover of platelet PPI during storage. These findings have important implications in relation to PAF receptor activity and viability of platelets at different periods of storage.

  6. 延续护理对单采血小板献血者持续献血的效果研究%Study on effects of continuing nursing on sustained blood donation of apheresis platelets donators

    Institute of Scientific and Technical Information of China (English)

    卢丽霞; 龙雪芳; 骆小青; 林巧核

    2016-01-01

    Objective:To discuss effects of continuing nursing on sustained blood donation of first - time apheresis platelets donators. Methods:Selected 120 first - time apheresis platelets donators in our hospital from August 2014 to August 2015,and randomly divided these study objects into control group and experimental group equally;control group donors received usual nursing while experimental group donors received intervention nursing under the continuing nursing mode,which included cognitive intervention,mental intervention and behavioral intervention. Sustained blood donation conditions of both groups were assessed within one year after the interventions. The assessed fields included number of platelet donors,number of volunteers,number of successfully recruited blood donors,number of donors who donated whole - blood and platelets alternately and number of donors who no longer donated platelets. Then changes in life styles of both group donors and their masteries of relevant knowledge were observed through analysis reports,so as to know about intervention effects. Results:Within 1 year after interventions,experimental group had more sustained apheresis platelets donator,volunteers,successfully recruited do-nors,but fewer donors who donated whole - blood and platelets alternately and donors who no longer donated platelets,the differences had statistical signifi-cances(P < 0. 05). Cognitive behaviors of donors,masteries of relevant knowledge and changes in life styles were compared between both groups,and the comparisons had statistical differences(P < 0. 05). Conclusion:Continuing nursing can encourage sustained blood donations of apheresis platelets donators, help them to change unhealthy living habits and increase their compliances. It plays an active role in recruitment,call back and conservation of donors.%目的:探讨延续护理对首次单采血小板献血者持续献血的效果。方法:选取我院2014年8月~2015年8月120名首次单采血小板献血

  7. Quality evaluation of red blood cell suspension and platelet concentrate separated and prepared from whole blood stored at 22℃ for 24 hours%全血于22℃保存24h分离制备悬浮红细胞及浓缩血小板的质量评价

    Institute of Scientific and Technical Information of China (English)

    黄彦; 符雪丽; 李诗敏; 梁若鹄; 高艳; 陈龙菊

    2016-01-01

    细胞混入量、储存期末pH值均符合《全血及成分血质量要求》(GB18469-2012)的相关规定;两组浓缩血小板的血小板含量、红细胞混入量、FHb水平、血小板黏附率、血小板聚集率,储存期末pH值,以及K+、Na+、Cl-浓度比较,差异均无统计学意义(t=0.17、0.16、0.56、2.43、0.36、2.50、1.85、1.75、0.32,P>0.05).结论 22℃保存24 h制备的悬浮红细胞、浓缩血小板的质量符合国家标准,全血22℃保存过夜分离制备悬浮红细胞、浓缩血小板的方法可行.%Objective To evaluate the quality of red blood cell suspension and platelet concentrate separated and prepared from whole blood stored at 22℃ for 24 h.Methods From May 2014 to February 2015,a total of 60 voluntary blood donors who were recruited by Maoming Central Blood Station of Guangdong Province were included into this study,using simple random sampling method.The inclusion criterion for subjects was that the physical examination and related hematology tests results of all blood donors before blood donation met the relevant regulations in the Whole Blood and Blood Component Donor Selection Requirements (GB18467-2011).All the 60 donors were randomly divided into study group (n =30) and control group (n=30).A total of 60 bags of whole blood (400 mL) were collected from the blood donors in the two groups,using quintuple blood collection bags.In the study group,the whole blood was stored and transported at 22 ℃,and prepared into red blood cell suspension and platelet concentrate 24 h after blood collection.In the control group,the whole blood was also stored and transported at 22 ℃,and prepared into red blood cell suspension and platelet concentrate within 8 h after blood collection.The preparation of red blood cell suspension and platelet concentrate in both groups was conducted by the buffy coat method.Red blood cell suspension was stored at 4 ℃ until the end of the storage period (35 d after preparation),and its

  8. State Analysis of the Apheresis Platelet Donors in Dali Blood Center%大理州中心血站机采血小板献血者结构状况分析

    Institute of Scientific and Technical Information of China (English)

    李剑波; 杨天富; 王永均; 杨宇珠; 季雯婕

    2015-01-01

    目的:了解大理州无偿机采血小板献血人群的结构及分布特征,为无偿献血招募提供科学依据,确保本地区机采血小板的临床供应.方法:用穿越血站管理信息系统中统计模块收集2005年至2013年在血站无偿捐献机采血小板的献血者资料,进行数据统计分析.结果:2005年至2013年共有机采血小板献血者889人次.其中,男性显著多于女性,占89.31%;年龄以25~35岁、36~45岁两个年龄段为主;初中及以下学历所占比例较大,占66.14%;职业以农民为主,占62.77%;血型分布特征为A>O>B>AB.结论:有针对性地做好无偿机采血小板献血宣传招募工作,建立一支稳定的机采血小板献血者队伍,以满足临床需要.%Objective:To understand the state and distribution of the voluntary apheresis platelet donors in Dali;to provide scientific basis for the recruitment of blood donation without compensation; and to ensure the local clinical supply of the apheresis platelet. Methods: The statistical module in the through blood stations management information system was used to collect the data from the apheresis platelet donors who voluntarily donated in our blood bank from 2005 to 2013 for statistical analysis. Results:The number of the blood donors from 2005 to 2013 is 889. Among them, the number of the men is obviously larger than that of women , accounting for 89.31%. There are two main age groups:aged from 25 to 35 and from 36 to 45. Most of them are junior school graduates and below, accounting for 66.14%;About 62.77%of them are famers;The characteristic of blood type distribution is A>O>B>AB. Conclusion:To satisfy clinical needs good recruitment of free donors and stable donation populator are important.

  9. Evaluation of storage performance of special plastic blood bags for apheresis platelets%血小板保存专用塑料血袋的储存性能评价

    Institute of Scientific and Technical Information of China (English)

    王捷熙; 韩颖; 周倩; 刘敏霞; 王艳; 柴丽娜; 卓海龙; 易晓阳; 周建伟; 王建卫

    2015-01-01

    Objective To evaluate the storage performance of storage bags for apheresis platelets produced by Shandong Weigao Group Medical Polymer Co .,Ltd ( experimental bags ) with Trima set platelet storage bags produced by the U .S. Gambro BCT as the control .Method One unit of apheresis platelets was divided into two equal parts , added to control blood bags and experimental blood bags respectively .All samples were stored at ( 22 ±2 )℃ with consecutive oscillation . The platelets′count, mean volume, aggregate activity (ADP, THR), pH, glucose, lactate concentration, lactate dehydro-genase concentration , hypotonic shock reaction , expression of CD62P and phosphatidyl serine on surface of cell membrane were detected at 0,3,5 and 7 d respectively.Results There was no significant difference in platelet quality after five days of storage between the experimental group and the control group (t-test, P>0.05).Conclusion Two types of platelet stor-age blood bags have similar storage performance for apheresis platelets .%目的:以美国Gambro BCT公司生产的Trima set血小板保存袋为对照,评价山东威高集团医用高分子制品股份有限公司生产的血小板保存袋对单采血小板的储存性能。方法将1U单采血小板平分成两份,分别加入实验血袋和对照血袋中,于血小板恒温振荡保存箱中保存。分别于保存0、3、5、7d取样,比较分析两组的血小板含量和血小板平均体积、pH值、体外聚集活性、氧分压和二氧化碳分压、葡萄糖、乳酸和乳酸脱氢酶浓度、低渗休克反应、血小板活化和凋亡、血小板形态结构及细菌培养试验。结果两种保存袋保存的血小板在保存期内,相同保存时间实验组与对照组之间各项检测结果差异无统计学意义(P>0.05);无菌试验均为阴性。结论国产血小板专用塑料血袋与美国Trima set血小板保存袋对该实验使用的15份单采血小板具有相似的储存性能。

  10. Modulatory effect of coffee on platelet function.

    Science.gov (United States)

    Bhaskar, Shobha; Rauf, Arun A

    2010-01-01

    Blood platelets play a major role in cardiovascular disease (CVD) and thrombosis. Conflicting information exists regarding the effect of coffee consumption on the cardiovascular system. We have investigated whether the consumption of moderate amount of coffee affect platelet functions and primary hemostasis in vivo in normal and high fat diet fed rats. Coffee fed group showed significant (P production from membrane arachidonic acid and it was decreased in coffee treated group. Platelet aggregation studies with ADP, collagen, arachidonic acid and epinephrine showed significant (P coffee fed group. Scanning electron microscopic studies revealed that platelet aggregation tendency increased in HFD group and was reduced in coffee fed group. These results indicate that coffee is active in inhibiting platelet aggregation, a critical step involved in thrombosis.

  11. P-selectin-mediated platelet adhesion promotes tumor growth.

    Science.gov (United States)

    Qi, Cuiling; Wei, Bo; Zhou, Weijie; Yang, Yang; Li, Bin; Guo, Simei; Li, Jialin; Ye, Jie; Li, Jiangchao; Zhang, Qianqian; Lan, Tian; He, Xiaodong; Cao, Liu; Zhou, Jia; Geng, Jianguo; Wang, Lijing

    2015-03-30

    Blood platelets foster carcinogenesis. We found that platelets are accumulated in human tumors. P-selectin deficiency and soluble P-selectin abolish platelet deposition within tumors, decreasing secretion of vascular endothelial growth factor and angiogenesis, thereby suppressing tumor growth. Binding of the P-selectin cytoplasmic tail to talin1 triggers the talin1 N-terminal head to interact with the β3 cytoplasmic tail. This activates αIIbβ3 and recruits platelets into tumors. Platelet infiltration into solid tumors occurs through a P-selectin-dependent mechanism.

  12. Platelets as immune mediators: Their role in host defense responses and sepsis

    OpenAIRE

    Li, Zhenyu; Yang, Fanmuyi; Dunn, Steve; Gross, A. Kendall; Smyth, Susan S.

    2010-01-01

    Platelets occupy a central role at the interface between thrombosis and inflammation. At sites of vascular damage, adherent platelets physically and functionally interact with circulating leukocytes. Activated platelets release soluble factors into circulation that may have local and systemic effects on blood and vascular cells. Platelets can also interact with a wide variety of microbial pathogens. Emerging evidence from animal models suggests that platelets may participate in a wide variety...

  13. Breaking the mold: transcription factors in the anucleate platelet and platelet-derived microparticles

    Directory of Open Access Journals (Sweden)

    Katie L Lannan

    2015-02-01

    Full Text Available Platelets are small anucleate blood cells derived from megakaryocytes. In addition to their pivotal roles in hemostasis, platelets are the smallest, yet most abundant, immune cell and regulate inflammation, immunity, and disease progression. Although platelets lack DNA, and thus no functional transcriptional activities, they are nonetheless rich sources of RNAs, possess an intact spliceosome, and are thus capable of synthesizing proteins. Previously, it was thought that platelet RNAs and translational machinery were remnants from the megakaryocyte. We now know that the initial description of platelets as cellular fragments is an antiquated notion, as mounting evidence suggests otherwise. Therefore, it is reasonable to hypothesize that platelet transcription factors are not vestigial remnants from megakaryoctes, but have important, if only partly understood functions. Proteins play multiple cellular roles to minimize energy expenditure for maximum cellular function; thus, the same can be expected for transcription factors. In fact, numerous transcription factors have non-genomic roles, both in platelets and in nucleated cells. Our lab and others have discovered the presence and nongenomic roles of transcription factors in platelets, such as the nuclear factor kappa β (NFκB family of proteins and peroxisome proliferator activated receptor gamma (PPARγ. In addition to numerous roles in regulating platelet activation, functional transcription factors can be transferred to vascular and immune cells through platelet microparticles. This method of transcellular delivery of key immune molecules may be a vital mechanism by which platelet transcription factors regulate inflammation and immunity. At the very least, platelets are an ideal model cell to dissect out the nongenomic roles of transcription factors in nucleated cells. There is abundant evidence to suggest that transcription factors in platelets play key roles in regulating inflammatory and

  14. Platelet function in brown bear (Ursus arctos compared to man

    Directory of Open Access Journals (Sweden)

    Särndahl Eva

    2010-06-01

    Full Text Available Abstract Background Information on hemostasis and platelet function in brown bear (Ursus arctos is of importance for understanding the physiological, protective changes during hibernation. Objective The study objective was to document platelet activity values in brown bears shortly after leaving the den and compare them to platelet function in healthy humans. Methods Blood was drawn from immobilized wild brown bears 7-10 days after leaving the den in mid April. Blood samples from healthy human adults before and after clopidogrel and acetylsalicylic acid administration served as control. We analyzed blood samples by standard blood testing and platelet aggregation was quantified after stimulation with various agonists using multiple electrode aggregometry within 3 hours of sampling. Results Blood samples were collected from 6 bears (3 females between 1 and 16 years old and from 10 healthy humans. Results of adenosine diphosphate, aspirin, and thrombin receptor activating peptide tests in bears were all half or less of those in humans. Platelet and white blood cell counts did not differ between species but brown bears had more and smaller red blood cells compared with humans. Conclusion Using three different tests, we conclude that platelet function is lower in brown bears compared to humans. Our findings represent the first descriptive study on platelet function in brown bears and may contribute to explain how bears can endure denning without obvious thrombus building. However, the possibility that our findings reflect test-dependent and not true biological variations in platelet reactivity needs further studies.

  15. Low-affinity FcγR interactions can decide the fate of novel human IgG-sensitised red blood cells and platelets.

    Science.gov (United States)

    Armour, Kathryn L; Smith, Cheryl S; Turner, Craig P; Kirton, Christopher M; Wilkes, Anthony M; Hadley, Andrew G; Ghevaert, Cedric; Williamson, Lorna M; Clark, Michael R

    2014-03-01

    G1Δnab is a mutant human IgG1 constant region with a lower ability to interact with FcγR than the natural IgG constant regions. Radiolabelled RBCs and platelets sensitised with specific G1Δnab Abs were cleared more slowly from human circulation than IgG1-sensitised counterparts. However, non-destructive splenic retention of G1Δnab-coated RBCs required investigation and plasma radioactivities now suggest this also occurred for platelets sensitised with an IgG1/G1Δnab mixture. In vitro assays with human cells showed that G1Δnab-sensitised RBCs did not cause FcγRI-mediated monocyte activation, FcγRIIIa-mediated antibody-dependent cell-mediated cytotoxicity (ADCC) or macrophage phagocytosis although they did adhere to macrophages. Thus, FcγRII was implicated in the adhesion despite the Δnab mutation reducing the already low-affinity binding to this receptor class. Additional contacts via P-selectin enhance the interaction of sensitised platelets with monocytes and this system provided evidence of FcγRII-dependent activation by G1Δnab. These results emphasise the physiological relevance of low-affinity interactions: It appears that FcγRII interactions of G1Δnab allowed splenic retention of G1Δnab-coated RBCs with inhibitory FcγRIIb binding preventing RBC destruction and that FcγRIIb engagement by G1Δnab on IgG1/G1Δnab-sensitised platelets overcame activation by IgG1. Considering therapeutic blocking Abs, G1Δnab offers lower FcγR binding and a greater bias towards inhibition than IgG2 and IgG4 constant regions.

  16. Influence of danazol on blood platelet counts of ITP patients%达那唑对ITP患者血小板数量的影响

    Institute of Scientific and Technical Information of China (English)

    蔡艳

    2012-01-01

    目的 观察达那唑对血小板减少性紫癜(ITP)患者血小板数量的影响,并探讨其机制.方法 回顾性分析31例ITP患者,以达那唑为主进行治疗,疗程为3个月,并于治疗前、后行血小板计数检测及疗效判定.结果 治疗后,完全反应17例,部分反应7例,微小反应5例,无反应2例,总有效率为93%.患者的血小板数目提升.结论 达那唑治疗ITP的临床疗效满意,能有效提升患者血小板数量.%Objective To observe the effect of danazol on platelet count of thrombocytopenic purpura pa tients, and investigate the mechanism. Methods 31 cases of ITP patients were analyzed retrospectively. The treatment ( main with danazol ) lasted for 3 months,the platelet counts and efficacy were determined. Results After treatment, there were 17 cases of complete response,7 cases of partial response,5 cases of minor response,2 cases without re sponse, the total effective rate was 93 % . The number of platelet was improved. Conclusion The effect of danazol on ITP is good,danazol can effectively increase the number of platelets of ITP patients.

  17. Reference intervals for platelet aggregation assessed by multiple electrode platelet aggregometry

    DEFF Research Database (Denmark)

    Rubak, Peter; Villadsen, Kirsten; Hvas, Anne-Mette

    2012-01-01

    Abstract Introduction Analyses of platelet aggregation in hirudin whole blood using Multiplate® was validated. Reference intervals for the most commonly used agonists were established, and the association between platelet aggregation, age, gender and haematological values was analysed. Material...... and methods We included 121 healthy individuals to establish reference intervals and six healthy individuals for evaluation of the day-to-day variation. Platelet aggregation was evaluated on hirudin whole blood employing Multiplate® induced by arachidonic acid, ADP, collagen and ristocetin (RISTOlow...... reference interval is presented as 95% confidence interval suitable for any age and both sex. Day-to-day variation was

  18. Platelet-Related Variants Identified by Exomechip Meta-analysis in 157,293 Individuals

    NARCIS (Netherlands)

    Eicher, J.D. (John D.); Chami, N. (Nathalie); T. Kacprowski (Tim); Nomura, A. (Akihiro); M.-H. Chen (Ming-Huei); L.R. Yanek (Lisa); Tajuddin, S.M. (Salman M.); U.M. Schick (Ursula); Slater, A.J. (Andrew J.); V.S. Pankratz (Shane); Polfus, L. (Linda); C. Schurmann (Claudia); Giri, A. (Ayush); J. Brody (Jennifer); L.A. Lange (Leslie); A. Manichaikul (Ani); W.D. Hill (W. David); R. Pazoki (Raha); Elliot, P. (Paul); E. Evangelou (Evangelos); I. Tzoulaki; Gao, H. (He); Vergnaud, A.-C. (Anne-Claire); J. Mathias (Jasmine); D.M. Becker (Diane); L.C. Becker (Lewis); A.D. Burt (Alastair); D.R. Crosslin (David); L.-P. Lyytikäinen (Leo-Pekka); K. Nikus (Kjell); Hernesniemi, J. (Jussi); M. Kähönen (Mika); Raitoharju, E. (Emma); K. Mononen (Kari); O.T. Raitakari (Olli T.); T. Lehtimäki (Terho); M. Cushman (Mary Ann); N.A. Zakai (Neil); D.A. Nickerson (Deborah); Raffield, L.M. (Laura M.); Quarells, R. (Rakale); C.J. Willer (Cristen); G.M. Peloso (Gina); G.R. Abecasis (Gonçalo); D. Liu (Dajiang); P. Deloukas (Panagiotis); N.J. Samani (Nilesh); H. Schunkert (Heribert); J. Erdmann (Jeanette); M. Fornage (Myriam); Richard, M. (Melissa); J.-C. Tardif (Jean-Claude); Rioux, J.D. (John D.); Dube, M.-P. (Marie-Pierre); de Denus, S. (Simon); Y. Lu (Yingchang); E.P. Bottinger (Erwin); R.J.F. Loos (Ruth); A.V. Smith (Albert Vernon); T.B. Harris (Tamara); Launer, L.J. (Lenore J.); V. Gudnason (Vilmundur); Velez Edwards, D.R. (Digna R.); Torstenson, E.S. (Eric S.); Y. Liu (Yongmei); R.P. Tracy (Russell); Rotter, J.I. (Jerome I.); S.S. Rich (Stephen); H. Highland (Heather); E.A. Boerwinkle (Eric); Li, J. (Jin); E.M. Lange (Ethan); J.F. Wilson (James); E. Mihailov (Evelin); R. Mägi (Reedik); J.N. Hirschhorn (Joel); A. Metspalu (Andres); T. Esko (Tõnu); Vacchi-Suzzi, C. (Caterina); M.A. Nalls (Michael); A.B. Zonderman; M. Evans (Michele); G. Engström; M. Orho-Melander (Marju); O. Melander (Olle); M.L. O'Donoghue (Michelle L.); D. Waterworth (Dawn); L.C. Wallentin (Lars); White, H.D. (Harvey D.); J. Floyd (James); T.M. Bartz (Traci M.); K.M. Rice (Kenneth); B.M. Psaty (Bruce); J.M. Starr (John); D.C. Liewald (David C.); C. Hayward (Caroline); I.J. Deary (Ian J.); A. Greinacher (Andreas); U. Völker (Uwe); Thiele, T. (Thomas); H. Völzke (Henry); F.J.A. van Rooij (Frank); A.G. Uitterlinden (André); O.H. Franco (Oscar); A. Dehghan (Abbas); T.L. Edwards (Todd L.); S.K. Ganesh (Santhi); S. Kathiresan (Sekar); Faraday, N. (Nauder); P. Auer (Paul); A. Reiner (Alexander); G. Lettre (Guillaume); A.D. Johnson (Andrew)

    2016-01-01

    textabstractPlatelet production, maintenance, and clearance are tightly controlled processes indicative of platelets’ important roles in hemostasis and thrombosis. Platelets are common targets for primary and secondary prevention of several conditions. They are monitored clinically by complete blood

  19. Evaluation of platelet thromboxane radioimmunoassay method to measure platelet life-span: Comparison with /sup 111/indium-platelet method

    Energy Technology Data Exchange (ETDEWEB)

    Vallabhajosula, S.; Machac, J.; Badimon, L.; Lipszyc, H.; Goldsmith, S.J.; Fuster, V.

    1985-05-01

    The platelet activation during radiolabeling in vitro with Cr-51 and In-111 may affect the platelet life-span (PLS) in vivo. A new RIA method to measure PLS is being evaluated. Aspirin inhibits platelet thromboxane (TxA/sub 2/) by acetylating cyclooxygenase. The time required for the TxA/sub 2/ levels to return towards control values depends on the rate of new platelets entering circulation and is a measure of PLS. A single dose of aspirin (150mg) was given to 5 normal human subjects. Blood samples were collected for 2 days before aspirin and daily for 10 days. TxA/sub 2/ production in response to endogenous thrombin was studied by allowing 1 ml blood sample to clot at 37/sup 0/C for 90 min. Serum TxB/sub 2/ (stable breakdown product of Tx-A/sub 2/) levels determined by RIA technique. The plot of TxB/sub 2/ levels (% control) against time showed a gradual increase. The PLS calculated by linear regression analysis assuming a 2-day lag period before cyclooxygenase recovery is 9.7 +- 2.37. In the same 5 subjects, platelets from a 50ml blood sample were labeled with /sup 111/In-tropolone in 2 ml autologous plasma. Starting at 1 hr after injection of labeled platelets, 10 blood samples were obtained over a 8 day period. The PLS calculated based on a linear regression analysis is 10.2 +. 1.4. The PLS measured from the rate of platelet disappearance from circulation and the rate of platelet regeneration into circulation are quite comparable in normal subjects. TxA/sub 2/ regeneration RIA may provide a method to measure PLS without administering radioactivity to patient.

  20. Propranolol modifies platelet serotonergic mechanisms in rats.

    Science.gov (United States)

    Zółtowski, R; Pawlak, R; Matys, T; Pietraszek, M; Buczko, W

    2002-06-01

    Though the mechanisms for the vascular actions of vasodilatory beta-blockers are mostly determined, some of their interactions with monoaminergic systems are not elucidated. Because there are evidences supporting a possible involvement of serotonin (5-HT) in the actions of beta-blockers, we studied the effect of propranolol on peripheral serotonergic mechanisms in normotensive and Goldblatt two-kidney - one clip (2K1C) hypertensive rats. In both groups of animals propranolol decreased systolic blood pressure, significantly increased whole blood serotonin concentration and at the same time it decreased platelet serotonin level. The uptake of the amine by platelets from hypertensive animals was lower than that of normotensive animals and it was decreased by propranolol only in the latter. In both groups propranolol inhibited potentiation of ADP-induced platelet aggregation by serotonin. In conclusion, this study provides evidence that propranolol modifies platelet serotonergic mechanisms in normotensive and renal hypertensive rats.

  1. Detection of dengue virus in platelets isolated from dengue patients.

    Science.gov (United States)

    Noisakran, Sansanee; Gibbons, Robert V; Songprakhon, Pucharee; Jairungsri, Aroonroong; Ajariyakhajorn, Chuanpis; Nisalak, Ananda; Jarman, Richard G; Malasit, Prida; Chokephaibulkit, Kulkanya; Perng, Guey Chuen

    2009-03-01

    Though thrombocytopenia or dysfunction of platelets is common in dengue virus infection, the role of platelets has not been established. We enrolled 33 hospitalized children with serologically confirmed dengue virus infection. Blood specimens were collected during hospitalization. Platelets and plasma were isolated from the whole blood. Detection of dengue virus in plasma and platelets was carried out by RT-PCR with primers that can differentiate different dengue serotypes simultaneously, and by electron transmission microscopy (EM). Dengue viral RNA was detected in the platelets and plasma by conventional RT-PCR. A significantly higher percentage of dengue viral RNA was detected in platelets than in plasma (p = 0.03). Platelets isolated 5 days after onset of fever were most likely positive for viral RNA. Concurrent infection or co-circulation with multiple dengue serotypes was observed in 12% of patients. Infrequently, negative-stranded dengue viral RNA was detected in platelets and in plasma. Importantly, EM confirmed the presence of dengue viral-like particles inside platelets prepared from dengue patients. Our findings suggest the presence of dengue virus in platelets may be associated with the dysfunction of platelets observed in dengue patients.

  2. Platelet satellitism in a trauma patient

    Science.gov (United States)

    Kopcinovic, Lara Milevoj; Pavic, Marina

    2012-01-01

    Platelet satellitism (PS) is a rare phenomenon observed in blood smears obtained from blood anticoagulated with EDTA. It is characterised by platelet rosetting around polymorphonuclear neutrophils and in rare cases around other blood cells. PS is a rare cause of pseudothrombocytopenia. References about the phenomenon of PS in medical literature are few. In this report we describe a case of PS fortunately noticed in one trauma patient. Furthermore, we discuss the possible pathophysiological mechanisms of PS proposed in the literature. To our knowledge this is the first case of PS reported in Croatia. PMID:22384529

  3. 献血者机采血小板后外周血细胞的变化分析%Analysis of the changes of peripheral blood cells of apheresis platelet donors before and after donation

    Institute of Scientific and Technical Information of China (English)

    贾春媛; 赵庆伟; 庞桂芝

    2015-01-01

    目的:分析机采血小板后献血者外周血细胞的变化情况,保障捐献者安全。方法随机选择51名机采血小板捐献者,对比分析机采血小板前后捐献者外周血液中WBC、RBC、Hct、HGB、RKW、PLT、MPV、PKW等指标。结果机采血小板后献血者WBC、RBC、Hct、HGB、PLT降低,MPV变大,PKW、RKW升高,但都在不影响捐献者个体健康的可控范围内,并且10 d后上述指标基本上都恢复到献血前的水平。结论机采血小板献血不会影响捐献者身体健康,可以促进骨髓的造血功能和血液的新陈代谢。%Objective To analyze the changes of peripheral blood cells of apheresis platelet donors before and after donation for protecting the safety of donors. Methods Fifty -one healthy donors were selected and detected WBC,RBC,Hct,HGB, RKW,PLT,MPV,PKW before and after donation. Results WBC, RBC,Hct,HGB and PLT were decreased,MPV,PKW and RKW of all enrolled donors were increased after donation. But it did not affect donors’health within a controllable range,and peripher-al blood indexes restored to pre-donation levels at 10th day after donation. Conclusion Apheresis platelet donation has no bad effect on the health of individuals and can promote hematopoiesis of the bone marrow and the metabolism of blood.

  4. The expression levels of platelet adhesive receptors in PRP derived platelet concentrates during storage

    Directory of Open Access Journals (Sweden)

    Fatemeh Nassaji

    2016-04-01

    Full Text Available Background: Major platelet adhesive receptors that contribute significantly to thrombus formation include platelet receptor glycoprotein Ibα (GPIbα of the GPIb-IX-V complex and platelet glycoprotein VI (GPVI. GPIbα plays a crucial role in platelet tethering to sub-endothelial matrix, which initiates thrombus formation at arterial shear rates, whereas GPVI is critically involved in platelets firm adhesion to the site of injury regardless of shear condition. During storage, platelets experience some changes that deleteriously affect the expression levels of platelet receptors, which in turn can alter platelet functional behaviors. Considering the important roles of GPIbα and GPVI in platelet adhesion, it seems that any dramatic changes in the expression levels of these receptors can influence adhesive function of transfused platelets. Thereby examining GPIbα and GPVI expression during the storage of platelet concentrates may provide some useful information about the functional quality of these products after transfusion. Methods: In our experimental study, 5 PRP-platelet concentrates were randomly obtained from Iranian Blood Transfusion Organization (IBTO. All the platelet products met the standard quality assessment based on AABB (American Association of Blood Banks guidelines. Washed platelets were subjected to flowcytometry analysis for the evaluation of GPIbα and GPVI receptor expression in day 1, 3 and 5 after storage. Data were presented as mean fluorescence intensity (MFI and analyzed by Kruskal-Wallis test with Dunn’s multiple comparison test. Results: The GPIbα expression on first day (MFI=86±5.9 was reduced three days after storage (MFI= 69±6.9. The expression levels continued to reduce until day 5 in which GPIbα expression was markedly decreased to (MFI= 61±7.7 (P= 0.0094. GPVI expression on the days 1, 3 and 5 after storage were 20.6±3.3, 24±2.5 and 14±4.9, respectively. The results showed a significant decrease of

  5. Understanding platelet generation from megakaryocytes: implications for in vitro-derived platelets.

    Science.gov (United States)

    Sim, Xiuli; Poncz, Mortimer; Gadue, Paul; French, Deborah L

    2016-03-10

    Platelets are anucleate cytoplasmic discs derived from megakaryocytes that circulate in the blood and have major roles in hemostasis, thrombosis, inflammation, and vascular biology. Platelet transfusions are required to prevent the potentially life-threatening complications of severe thrombocytopenia seen in a variety of medical settings including cancer therapy, trauma, and sepsis. Platelets used in the clinic are currently donor-derived which is associated with concerns over sufficient availability, quality, and complications due to immunologic and/or infectious issues. To overcome our dependence on donor-derived platelets for transfusion, efforts have been made to generate in vitro-based platelets. Work in this area has advanced our understanding of the complex processes that megakaryocytes must undergo to generate platelets both in vivo and in vitro. This knowledge has also defined the challenges that must be overcome to bring in vitro-based platelet manufacturing to a clinical reality. This review will focus on our understanding of committed megakaryocytes and platelet release in vivo and in vitro, and how this knowledge can guide the development of in vitro-derived platelets for clinical application.

  6. The phenotype of platelet CD36 deficiency in the blood donors of Shenzhen, China%深圳地区无偿献血者群体CD36抗原缺失型的表型分析

    Institute of Scientific and Technical Information of China (English)

    李大成; 蓝欲晓; 鲍自谦; 孙革; 钟福玲; 苏宇清

    2012-01-01

    Objective To analyze the phenotype and frequency of the CD36 deficiency among the volunteer blood donors in Shenzhen. Methods The phenotypes of CD36 deficiency were analyzed by monoclonal antibodies and flow cytome-try (FCM). Platelet-reactive antibodies in the plasmas of suspected donors were screened by the antigen capture enzyme-linked immmnosorbent assay and platelet suspension immunofluorescence test Results The frequency of CD36 deficiency among blood donors was found to be 3.06% (10/327 ), and the frequencies of type Ⅰ and Ⅱ deficiencies were found in 0. 31% (1/327) and 2.75% (9/327) .respectively. No platelet-reactive antibodies were detected in the plasmas of 3 female donors with CD36 deficiency. Conclusion The frequencies of CD36 deficiency in blood donors of Shenzhen are found that the same ranges with the other Asians. These results suggest the necessity to concern the clinical effects of isoimmunization caused by CD36 deficiency in transfusion medicine.%目的 分析深圳地区无偿献血者群体CD36抗原缺失型的筛查和表型情况.方法 应用单克隆抗体和流式细胞技术在327名献血者中检测CD36抗原缺失型个体,应用血小板单克隆抗体捕获酶联免疫技术和流式细胞术筛查献血者血浆中的血小板抗体.结果 此次筛查得到的深圳献血者的CD36抗原缺失型频率为3.06%( 10/327),其中Ⅰ型占0.31% (1/327),Ⅱ型占2.75% (9/327);在3名女性CD36抗原缺失型献血者的血浆中,均未检出血小板反应性抗体,包括抗-CD36.结论 深圳地区献血者群体中存在CD36抗原缺失型个体,其频率与亚洲其他地区人群的频率相当;对CD36的同簇免疫应该予以重视.

  7. 血液病患者单采血小板输注无效的原因及对策%Reasons for apheresis platelet transfusion refractory on patients with blood disorder and its countermeasures

    Institute of Scientific and Technical Information of China (English)

    沈胜建; 赵明峰; 张宇辰

    2014-01-01

    目的:探讨血液病患者单采血小板输注无效( PTR)发生率及其影响因素,为临床正确应用血小板制剂提供指导。方法回顾性分析单采血小板输注的70例患者318例次输注资料,通过计算血小板计数增加指数和血小板恢复百分率结合患者出血状况有无改善,判断血小板输注有效性,并讨论其影响因素及处理措施。结果急性白血病、再生障碍性贫血、骨髓异常综合征和特发性血小板减少性紫癜患者PTR发生率分别为22.1%、25.5%、38.3%和51.2%,四种类型的血液病患者血小板PTR发生率差别有统计学意义(P均<0.05);同种疾病无并发症患者PTR发生率低于有并发症者(P<0.05);无并发症患者PTR发生率随着输注次数的增加而上升(P<0.05)。未过滤白细胞与过滤白细胞患者PTR发生率比较差异有统计学意义( P<0.05)。结论疾病类型、有无并发症等因素影响血液病患者血小板输注的治疗效果,减少并发症、过滤白细胞可提高血小板的输注效果。%Objective To explore incidence rate and influence factor of apheresis platelet transfusion refractory ( PTR) on patients with blood disorder .Methods The data of 318 infusions for 70 patients subject to apheresis platelet infusion were retrospectively analyzed , by calculating corrected Count increment ( CCI ) and percent platelet recovery ( PPR) and combining hemorrhage improvement condition in patients , the effect of platelet transfusion were determined and influence factors and treatment measures were discussed .Results ①The PTR occurrence rate of acute leukemia (AL), aplastic anemia (AA), bone marrow abnormalities syndrome (MDS) and idiopathic thrombocytopenic purpura (ITP) in patients hit 22.1%, 25.5%, 38.3%and 22.1%respectively, the difference in platelet PTR rate in four types of blood diseases was statistically significant (P<0.05).②The difference

  8. Gut Microbial Metabolite TMAO Enhances Platelet Hyperreactivity and Thrombosis Risk.

    Science.gov (United States)

    Zhu, Weifei; Gregory, Jill C; Org, Elin; Buffa, Jennifer A; Gupta, Nilaksh; Wang, Zeneng; Li, Lin; Fu, Xiaoming; Wu, Yuping; Mehrabian, Margarete; Sartor, R Balfour; McIntyre, Thomas M; Silverstein, Roy L; Tang, W H Wilson; DiDonato, Joseph A; Brown, J Mark; Lusis, Aldons J; Hazen, Stanley L

    2016-03-24

    Normal platelet function is critical to blood hemostasis and maintenance of a closed circulatory system. Heightened platelet reactivity, however, is associated with cardiometabolic diseases and enhanced potential for thrombotic events. We now show gut microbes, through generation of trimethylamine N-oxide (TMAO), directly contribute to platelet hyperreactivity and enhanced thrombosis potential. Plasma TMAO levels in subjects (n > 4,000) independently predicted incident (3 years) thrombosis (heart attack, stroke) risk. Direct exposure of platelets to TMAO enhanced sub-maximal stimulus-dependent platelet activation from multiple agonists through augmented Ca(2+) release from intracellular stores. Animal model studies employing dietary choline or TMAO, germ-free mice, and microbial transplantation collectively confirm a role for gut microbiota and TMAO in modulating platelet hyperresponsiveness and thrombosis potential and identify microbial taxa associated with plasma TMAO and thrombosis potential. Collectively, the present results reveal a previously unrecognized mechanistic link between specific dietary nutrients, gut microbes, platelet function, and thrombosis risk.

  9. Evaluation of platelet aggregation in platelet concentrates: storage implications

    Directory of Open Access Journals (Sweden)

    Neiva Teresinha J.C.

    2003-01-01

    Full Text Available The use of hemo-derivatives is nowadays a fundamentally important therapeutic modality in the exercise of medicine. Among the various hemo-components employed, we have the platelet concentrate (PC, indicated in cases of hemorrhagic disturbances. We previously showed that platelet function in blood donors is reduced in their screening phase and after the separation process of PCs. Currently, we are providing evidence for the existence of biochemical and functional changes in PC preparations stored for three days at temperatures of 20 ± 2 ºC. Platelet concentrates from 40 healthy donors, collected in CPD anticoagulant and PL-146 polyvinylchloride containers, were examined in order to determine the pH value, pCO2 ,pO2 and lactate concentrations. In addition, the aggregation of platelets with thrombin and collagen were examined to evaluate platelet function. A pH increase from 7.07 ± 0.04 to 7.36 ± 0.07 (p < 0.01 was observed. The pCO2 concentration decreased progressively from 69.2 ± 7.7 mmHg to 28.8 ± 6.2 mmHg (p < 0.001 during the storage period. In contrast, pO2 value increase from 103.4 ± 30.6 to 152.3 ± 24.6 mmHg (p < 0.001 was evidenced during the 48 hours of storage. The lactate concentration increased from 17.97 ± 5.2 to 57.21 ± 5.7 mg/dl (p < 0.001. Platelet aggregation using 0.25 U/ml-thrombin and 2.0 µg/ml-collagen showed significant hypofunction from 61.8 ± 2.7% to 24.8 ± 9.8% and 62.7±5.0 to 33.4± 6.2 (p < 0.001, respectively. We concluded that the evaluated biochemical parameters and the platelet function changed significantly when the platelets were kept under routine storage conditions.

  10. Blood

    Science.gov (United States)

    ... Also, blood is either Rh-positive or Rh-negative. So if you have type A blood, it's either A positive or A negative. Which type you are is important if you need a blood transfusion. And your Rh factor could be important ...

  11. Heparin platelet factor 4 antibody positivity in pseudothrombocytopenia.

    Science.gov (United States)

    Balcik, Ozlem Sahin; Akdeniz, Derya; Cipil, Handan; Uysal, Sema; Isik, Ayse; Kosar, Ali

    2012-01-01

    Pseudothrombocytopenia (PTCP) is a laboratory event of platelet clustering related to drugs used for anticoagulation. This condition is engendered by autoantibodies against platelets in usually EDTA-anticoagulated blood. Pseudothrombocytopenia has no clinical significance but when evaluated as true thrombocytopenia, this misconception may lead to unnecessary diagnostic procedures. Heparin-induced thrombocytopenia with thrombosis (HITT) is a complication of heparin treatment caused by heparin platelet factor 4 (HPF-4) antibodies, leading to platelet activation and hypercoagulability. In our study, 48 patients with PTCP and 36 healthy volunteers were included. Heparin platelet factor 4 antibody positivity was detected in 12 patients from PTCP group; nobody from control group had. Citrated serum samples and peripheral blood smears showed normal platelet count. Of the 4 patients using heparin derivative, 1 (2.1%) had antibody positivity but without any bleeding symptoms. In conclusion, HPF-4 antibody positivity might be a risk factor for PTCP. Clinicians should be aware of this kind of condition.

  12. An Evaluation of the Accuracy of the Subtraction Method Used for Determining Platelet Counts in Advanced Platelet-Rich Fibrin and Concentrated Growth Factor Preparations

    Directory of Open Access Journals (Sweden)

    Taisuke Watanabe

    2017-01-01

    Full Text Available Platelet concentrates should be quality-assured of purity and identity prior to clinical use. Unlike for the liquid form of platelet-rich plasma, platelet counts cannot be directly determined in solid fibrin clots and are instead calculated by subtracting the counts in other liquid or semi-clotted fractions from those in whole blood samples. Having long suspected the validity of this method, we herein examined the possible loss of platelets in the preparation process. Blood samples collected from healthy male donors were immediately centrifuged for advanced platelet-rich fibrin (A-PRF and concentrated growth factors (CGF according to recommended centrifugal protocols. Blood cells in liquid and semi-clotted fractions were directly counted. Platelets aggregated on clot surfaces were observed by scanning electron microscopy. A higher centrifugal force increased the numbers of platelets and platelet aggregates in the liquid red blood cell fraction and the semi-clotted red thrombus in the presence and absence of the anticoagulant, respectively. Nevertheless, the calculated platelet counts in A-PRF/CGF preparations were much higher than expected, rendering the currently accepted subtraction method inaccurate for determining platelet counts in fibrin clots. To ensure the quality of solid types of platelet concentrates chairside in a timely manner, a simple and accurate platelet-counting method should be developed immediately.

  13. Synthesis, characterizations and applications of some nanomaterials (TiO2 and SiC nanostructured films, organized CNT structures, ZnO structures and CNT{blood platelet clusters)

    Indian Academy of Sciences (India)

    O N Srivastava; A Srivastava; D Dash; D P Singh; R M Yadava; P R Mishra; J Singh

    2005-10-01

    TiO2 nanostructured films have been synthesized by the hydrolysis of Ti[OCH(CH3)2]4 as the precursor. These films have been utilized for the dissociation of phenol contaminant in water. Free-standing nanostructured film of silicon carbide (SiC) has been synthesized, employing a simple and new route of spray pyrolysis technique utilizing a slurry of Si in hexane. Another study is done on organized carbon nanotube (CNT) structures. These are made in the form of hollow cylinders (50 mm length, 4 mm diameter and 1.5 mm wall thickness). These CNT-based cylinders are made of conventional CNT and bamboo-shaped CNT. The filtrations of heavy hydrocarbons and . coli bacteria from water have been carried out. In addition to this, ZnO nanostructures have also been studied. Another study concerns CNT-blood platelet clusters.

  14. Pegylated G-CSF Inhibits Blood Cell Depletion, Increases Platelets, Blocks Splenomegaly, and Improves Survival after Whole-Body Ionizing Irradiation but Not after Irradiation Combined with Burn

    Directory of Open Access Journals (Sweden)

    Juliann G. Kiang

    2014-01-01

    Full Text Available Exposure to ionizing radiation alone (radiation injury, RI or combined with traumatic tissue injury (radiation combined injury, CI is a crucial life-threatening factor in nuclear and radiological accidents. As demonstrated in animal models, CI results in greater mortality than RI. In our laboratory, we found that B6D2F1/J female mice exposed to 60Co-γ-photon radiation followed by 15% total-body-surface-area skin burns experienced an increment of 18% higher mortality over a 30-day observation period compared to irradiation alone; that was accompanied by severe cytopenia, thrombopenia, erythropenia, and anemia. At the 30th day after injury, neutrophils, lymphocytes, and platelets still remained very low in surviving RI and CI mice. In contrast, their RBC, hemoglobin, and hematocrit were similar to basal levels. Comparing CI and RI mice, only RI induced splenomegaly. Both RI and CI resulted in bone marrow cell depletion. It was observed that only the RI mice treated with pegylated G-CSF after RI resulted in 100% survival over the 30-day period, and pegylated G-CSF mitigated RI-induced body-weight loss and depletion of WBC and platelets. Peg-G-CSF treatment sustained RBC balance, hemoglobin levels, and hematocrits and inhibited splenomegaly after RI. The results suggest that pegylated G-CSF effectively sustained animal survival by mitigating radiation-induced cytopenia, thrombopenia, erythropenia, and anemia.

  15. Genetic engineering of platelets to neutralize circulating tumor cells.

    Science.gov (United States)

    Li, Jiahe; Sharkey, Charles C; Wun, Brittany; Liesveld, Jane L; King, Michael R

    2016-04-28

    Mounting experimental evidence demonstrates that platelets support cancer metastasis. Within the circulatory system, platelets guard circulating tumor cells (CTCs) from immune elimination and promote their arrest at the endothelium, supporting CTC extravasation into secondary sites. Neutralization of CTCs in blood circulation can potentially attenuate metastases to distant organs. Therefore, extensive studies have explored the blockade of platelet-CTC interactions as an anti-metastatic strategy. Such an intervention approach, however, may cause bleeding disorders since the platelet-CTC interactions inherently rely on the blood coagulation cascade including platelet activation. On the other hand, platelets have been genetically engineered to correct inherited bleeding disorders in both animal models and human clinical trials. In this study, inspired by the physical association between platelets and CTCs, platelets were genetically modified to express surface-bound tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), a cytokine known to induce apoptosis specifically in tumor cells. The TRAIL-expressing platelets were demonstrated to kill cancer cells in vitro and significantly reduce metastases in a mouse model of prostate cancer metastasis. Our results suggest that using platelets to produce and deliver cancer-specific therapeutics can provide a Trojan-horse strategy of neutralizing CTCs to attenuate metastasis.

  16. Platelet adhesion studies on dipyridamole coated polyurethane surfaces

    Directory of Open Access Journals (Sweden)

    Aldenhoff Y. B.J.

    2003-06-01

    Full Text Available Surface modification of polyurethanes (PUs by covalent attachment of dipyridamole (Persantinregistered is known to reduce adherence of blood platelets upon exposure to human platelet rich plasma (PRP. This effect was investigated in further detail. First platelet adhesion under static conditions was studied with four different biomaterial surfaces: untreated PU, PU immobilised with conjugate molecule 1, PU immobilised with conjugate molecule 2, and PU immobilised with conjugate molecule 3. In PU immobilised with 1 dipyridamole is directly linked to the surface, in PU immobilised with 2 there is a short hydrophilic spacer chain in between the surface and the dipyridamole, while conjugate molecule 3 is merely the spacer chain. Scanning electron microscopy (SEM was used to characterise platelet adhesion from human PRP under static conditions, and fluorescence imaging microscopy was used to study platelet adhesion from whole blood under flow. SEM experiments encompassed both density measurements and analysis of the morphology of adherent platelets. In the static experiments the surface immobilised with 2 showed the lowest platelet adherence. No difference between the three modified surfaces emerged from the flow experiments. The surfaces were also incubated with washed blood platelets and labeled with Oregon-Green Annexin V. No capture of Oregon-Green Annexin V was seen, implying that the adhered platelets did not expose any phosphatidyl serine at their exteriour surface.

  17. Platelets of patients with chronic kidney disease demonstrate deficient platelet reactivity in vitro

    Directory of Open Access Journals (Sweden)

    van Bladel Esther R

    2012-09-01

    Full Text Available Abstract Background In patients with chronic kidney disease studies focusing on platelet function and properties often are non-conclusive whereas only few studies use functional platelet tests. In this study we evaluated a recently developed functional flow cytometry based assay for the analysis of platelet function in chronic kidney disease. Methods Platelet reactivity was measured using flow cytometric analysis. Platelets in whole blood were triggered with different concentrations of agonists (TRAP, ADP, CRP. Platelet activation was quantified with staining for P-selectin, measuring the mean fluorescence intensity. Area under the curve and the concentration of half-maximal response were determined. Results We studied 23 patients with chronic kidney disease (9 patients with cardiorenal failure and 14 patients with end stage renal disease and 19 healthy controls. Expression of P-selectin on the platelet surface measured as mean fluorescence intensity was significantly less in chronic kidney disease patients compared to controls after maximal stimulation with TRAP (9.7 (7.9-10.8 vs. 11.4 (9.2-12.2, P = 0.032, ADP (1.6 (1.2-2.1 vs. 2.6 (1.9-3.5, P = 0.002 and CRP (9.2 (8.5-10.8 vs. 11.5 (9.5-12.9, P = 0.004. Also the area under the curve was significantly different. There was no significant difference in half-maximal response between both groups. Conclusion In this study we found that patients with chronic kidney disease show reduced platelet reactivity in response of ADP, TRAP and CRP compared to controls. These results contribute to our understanding of the aberrant platelet function observed in patients with chronic kidney disease and emphasize the significance of using functional whole blood platelet activation assays.

  18. Effects of irradiation on platelet function

    Energy Technology Data Exchange (ETDEWEB)

    Rock, G.; Adams, G.A.; Labow, R.S.

    1988-09-01

    Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products.

  19. Platelet Adhesion to Podoplanin Under Flow is Mediated by the Receptor CLEC-2 and Stabilised by Src/Syk-Dependent Platelet Signalling

    Science.gov (United States)

    Pollitt, Alice Y.; Lowe, Kate; Latif, Arusa; Nash, Gerard B.

    2015-01-01

    Summary Platelet-specific deletion of CLEC-2, which signals through Src and Syk kinases, or global deletion of its ligand podoplanin results in blood-filled lymphatics during mouse development. Platelet-specific Syk deficiency phenocopies this defect, indicating that platelet activation is required for lymphatic development. In the present study, we investigated whether CLEC-2-podoplanin interactions could support platelet arrest from blood flow and whether platelet signalling is required for stable platelet adhesion to lymphatic endothelial cells (LECs) and recombinant podoplanin under flow. Perfusion of human or mouse blood over human LEC monolayers led to platelet adhesion and aggregation. Following αIIbβ3 blockade, individual platelets still adhered. Platelet binding occurred at venous but not arterial shear rates. There was no adhesion using CLEC-2-deficient blood or to vascular endothelial cells (which lack podoplanin). Perfusion of human blood over human Fc-podoplanin (hFcPDPN) in the presence of monoclonal antibody IV.3 to block FcγRIIA receptors led to platelet arrest at similar shear rates to those used on LECs. Src and Syk inhibitors significantly reduced global adhesion of human or mouse platelets to LECs and hFcPDPN. A similar result was seen using Syk-deficient mouse platelets. Reduced platelet adhesion was due to a decrease in the stability of binding. In conclusion, our data reveal that CLEC-2 is an adhesive receptor that supports platelet arrest to podoplanin under venous shear. Src/Syk-dependent signalling stabilises platelet adhesion to podoplanin, providing a possible molecular mechanism contributing to the lymphatic defects of Syk-deficient mice. PMID:25694214

  20. Assessment of quality of platelets preserved in plasma and platelet additive solution: A Malaysian experience

    Directory of Open Access Journals (Sweden)

    Munirah Binti Mokhtar

    2016-01-01

    Full Text Available Background: A use of platelet additives solution (PAS improves storage conditions so as to give increased shelf life to platelets and to maintain hemostatic function. Objective: The present study was aimed to compare in vitro quality of platelet rich plasma (PRP-derived platelet concentrate (PC during extended period of storage in plasma and in additive solution (Composol PS and Fresenius. Study Design: Randomized 19 PCs each were used in the study for plasma and PAS as the storage medium. The measurement parameters, including pH, total white blood cell (WBC count, total platelet count, and platelet activation rate, were studied on day 1, day 5, and day 8 of the storage period. The sterility test was carried out on the eighth day of storage. Results: pH of PC suspended in PAS was significantly lower as compared to that in plasma (P < 0.001 for all the three days of sampling. The WBC count, both in plasma and in PAS, showed an acceptable values of being <0.2 Χ 10 9 /unit during the storage period. Platelet count in PAS was higher as compared to that in plasma, though it was not statistically significant. While both the groups showed increased platelet activation rate during the storage, the PCs suspended in PAS showed significantly higher platelet activation rate (p0.001. Results from sterility test showed no bacterial growth in the PCs in both the groups. Conclusion: Most parameters studied on platelet storage in suspending medium of native plasma and PAS remained well within the acceptable limits. However, the pH values and platelet activation rate significantly differed in PAS as compared with plasma.

  1. Effects of drugs on platelet function.

    Science.gov (United States)

    Morse, E E

    1977-01-01

    Numerous drugs and chemicals affect the function of human blood platelets. The mechanism of action of some medications is partly understood. Aspirin is the most frequently involved drug. It appears to interfere with the platelet release reaction by acetylation of a platelet membrane protein which may be involved in the synthesis of prostaglandins. Other anti-inflammatory drugs, including indomethacin, phenylbutazone, ibuprophen (Motrin) and clonixin, also interfere with the release reaction but have a shorter acting course than aspirin. Some drugs stimulate adenylcyclase (gliclazide) or block phosphodiesterase, (dipyridamole, caffeine) both of which actions lead to an increase in adenosine cyclic 3':5' monophosphate (cAMP) and decrease aggregation by adenosine diphosphate (ADP). These interactions should be known to clinical scientists since patients using these medicaments may manifest abnormal platelet function tests in the laboratory and mild hemorrhagic syndromes in the clinic.

  2. Analysis of Platelet-Rich Plasma Extraction

    Science.gov (United States)

    Fitzpatrick, Jane; Bulsara, Max K.; McCrory, Paul Robert; Richardson, Martin D.; Zheng, Ming Hao

    2017-01-01

    Background: Platelet-rich plasma (PRP) has been extensively used as a treatment in tissue healing in tendinopathy, muscle injury, and osteoarthritis. However, there is variation in methods of extraction, and this produces different types of PRP. Purpose: To determine the composition of PRP obtained from 4 commercial separation kits, which would allow assessment of current classification systems used in cross-study comparisons. Study Design: Controlled laboratory study. Methods: Three normal adults each donated 181 mL of whole blood, some of which served as a control and the remainder of which was processed through 4 PRP separation kits: GPS III (Biomet Biologics), Smart-Prep2 (Harvest Terumo), Magellan (Arteriocyte Medical Systems), and ACP (Device Technologies). The resultant PRP was tested for platelet count, red blood cell count, and white blood cell count, including differential in a commercial pathology laboratory. Glucose and pH measurements were obtained from a blood gas autoanalyzer machine. Results: Three kits taking samples from the “buffy coat layer” were found to have greater concentrations of platelets (3-6 times baseline), while 1 kit taking samples from plasma was found to have platelet concentrations of only 1.5 times baseline. The same 3 kits produced an increased concentration of white blood cells (3-6 times baseline); these consisted of neutrophils, leukocytes, and monocytes. This represents high concentrations of platelets and white blood cells. A small drop in pH was thought to relate to the citrate used in the sample preparation. Interestingly, an unexpected increase in glucose concentrations, with 3 to 6 times greater than baseline levels, was found in all samples. Conclusion: This study reveals the variation of blood components, including platelets, red blood cells, leukocytes, pH, and glucose in PRP extractions. The high concentrations of cells are important, as the white blood cell count in PRP samples has frequently been ignored

  3. [Erythrocytes infected by Plasmodium falciparum activate human platelets].

    Science.gov (United States)

    Polack, B; Peyron, F; Sheick Zadiuddin, I; Kolodié, L; Ambroise-Thomas, P

    1990-01-01

    Blood platelets are involved in Plasmodium falciparum malaria pathology as shown by thrombocytopenia and increased plasma level of two alpha granule proteins: beta thromboglobulin (beta TG) and platelet factor 4 (PF4). In this study we demonstrate that Plasmodium falciparum parasitized erythrocytes activate directly the secretion of beta TG and PF4 by human platelets. This secretion is related to parasitemia and occurs immediately after contact. Treatment of parasited erythrocytes by trypsin and diffusion chamber experiments suggest that platelet activation is triggered by parasitic substances shed on erythrocyte membrane and released in the culture medium.

  4. A General Aspect of Platelet Rich Plasma

    Directory of Open Access Journals (Sweden)

    Onur ORAL

    2015-08-01

    Full Text Available The aim of this scientific paper is to introduce Platelet Rich Plasma (PRP cure method by people who never heard about it. People can hurt their selves, thus they can have damaged tissue; for instance broken bone, a scar or a wounded area. Furthe rmore damaged tissue can be a cartilage tissue, which takes very long time to heal. Platelets, those exist in the veins as thrombus, come up to repair those damaged tissues. However, platelets would be insufficient to cure damaged area in a short time. At this point PRP cure method give a hand to the healing process. By centrifuging people’s own blood via special kits, platelets can be separated from blood cells as plasma. That plasma’s platelet density is 3 - 5 times greater than that blood’s platelet densit y. Afterwards PRP method is implemented by injection of plasma to the damaged area or tissue. After implementation of 2 - 4 sessions per week, damaged tissue can be regenerated. It is fast healing method because densified platelet plasma is used; and it is s afe because that plasma is obtained from people’s own blood. PRP can be implemented on many areas; for instance on dentistry, sports medicine, different kind of surgeries such as plastic, vascular or orthopedic and so on. When soccer players brake their le gs, their sports life come to the end, but what if their broken legs was healed better and faster than general healing process? To sum up, PRP is very safe and the future of healing process.

  5. Effects of pathogen reduction systems on platelet microRNAs, mRNAs, activation, and function.

    Science.gov (United States)

    Osman, Abdimajid; Hitzler, Walter E; Meyer, Claudius U; Landry, Patricia; Corduan, Aurélie; Laffont, Benoit; Boilard, Eric; Hellstern, Peter; Vamvakas, Eleftherios C; Provost, Patrick

    2015-01-01

    Pathogen reduction (PR) systems for platelets, based on chemically induced cross-linking and inactivation of nucleic acids, potentially prevent transfusion transmission of infectious agents, but can increase clinically significant bleeding in some clinical studies. Here, we documented the effects of PR systems on microRNA and mRNA levels of platelets stored in the blood bank, and assessed their impact on platelet activation and function. Unlike platelets subjected to gamma irradiation or stored in additive solution, platelets treated with Intercept (amotosalen+ ultraviolet-A [UVA] light) exhibited significantly reduced levels of 6 of the 11 microRNAs, and 2 of the 3 anti-apoptotic mRNAs (Bcl-xl and Clusterin) that we monitored, compared with platelets stored in plasma. Mirasol (riboflavin+ UVB light) treatment of platelets did not produce these effects. PR neither affected platelet microRNA synthesis or function nor induced cross-linking of microRNA-sized endogenous platelet RNA species. However, the reduction in the platelet microRNA levels induced by Intercept correlated with the platelet activation (p platelet aggregation response to ADP (p platelet activation, resulting in the release of microRNAs and mRNAs from platelets. The clinical implications of this reduction in platelet nucleic acids secondary to Intercept remain to be established.

  6. Effects of clopidogrel therapy on whole blood platelet aggregation, the Plateletworks® assay and coagulation parameters in cats with asymptomatic hypertrophic cardiomyopathy : a pilot study

    NARCIS (Netherlands)

    den Toom, M L; van Leeuwen, M W; Szatmári, V; Teske, E

    2017-01-01

    BACKGROUND: Although scientific evidence is limited, clopidogrel is frequently used as prophylaxis for arterial thromboembolism in cats with hypertrophic cardiomyopathy (HCM). OBJECTIVES: Evaluating effects of clopidogrel therapy in asymptomatic cats with HCM on (1) conventional whole blood aggregat

  7. Comparison Between Human and Porcine Thromboelastograph Parameters in Response to Ex-Vivo Changes to Platelets, Plasma, and Red Blood Cells

    Science.gov (United States)

    2013-01-01

    and angle that confirmed that the swine are hypercoagulable compared with humans. Superficially similar TEG tracing patterns can be produced by divergent mechanisms associated with altered concentrations of blood components .

  8. Beyond the platelet count: immature platelet fraction and thromboelastometry correlate with bleeding in patients with immune thrombocytopenia.

    Science.gov (United States)

    Greene, Lindsey A; Chen, Siqi; Seery, Caroline; Imahiyerobo, Allison M; Bussel, James B

    2014-08-01

    Platelet counts (PC) estimate bleeding risk in Immune Thrombocytopenia (ITP). We investigated whether measures of thromboelastometry and absolute immature platelet fraction (A-IPF) would correlate better with acute bleeding score (ABS) than PC or mean platelet volume (MPV). Simultaneous determination of ABS, complete blood count and thromboelastometry was performed in 141 ITP patients; 112 underwent A-IPF testing. Subgroup analyses were performed for paediatric subjects, PC children with PC children and children with PC platelet function, contribute to ITP bleeding pathophysiology. Thromboelastometry, A-IPF and ABS can be incorporated into routine or acute visits.

  9. Platelet serotonin content and uptake in spontaneously hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Guicheney, P.; Legros, M.; Marcel, D.; Kamal, L.; Meyer, P.

    1985-02-18

    Platelet serotonin (5-HT) content and uptake were studied in male SHR and WKY at various ages. Blood was withdrawn from the carotid artery under anesthesia and 5-HT levels determined from platelet rich plasma (PRP) using a HPLC technique coupled with an electrochemical detection method. Platelet 5-HT uptake was studied by incubating PRP at 37/sup 0/C for 10 sec with increasing concentrations of /sup 3/H-5HT. Lineweaver-Burk plots of /sup 3/H-5HT uptake were linear suggesting simple Michaelis-Menten uptake kinetics. The SHR had more platelets than age-matched controls and consequently a higher blood circulating pool of 5-HT. Nevertheless, the 5-HT platelet levels were similar to those of their age-matched rats. The 5 week-old SHR and WKY had greater numbers of platelets and higher 5-HT platelet levels than the older rats of both strains. The affinity constants (Km) and the maximal velocities (Vmax) of platelet 5-HT uptake did not differ significantly between the 12 week- and the 6 month-old SHR and WKY. These data suggest that the SHR do not show the same impairment in platelet 5-HT metabolism as observed in essential hypertension in man.

  10. Generation of functional platelets from canine induced pluripotent stem cells.

    Science.gov (United States)

    Nishimura, Toshiya; Hatoya, Shingo; Kanegi, Ryoji; Sugiura, Kikuya; Wijewardana, Viskam; Kuwamura, Mitsuru; Tanaka, Miyuu; Yamate, Jyoji; Izawa, Takeshi; Takahashi, Masahiro; Kawate, Noritoshi; Tamada, Hiromichi; Imai, Hiroshi; Inaba, Toshio

    2013-07-15

    Thrombocytopenia (TTP) is a blood disease common to canines and human beings. Currently, there is no valid therapy for this disease except blood transfusion. In this study, we report the generation of canine induced pluripotent stem cells (ciPSCs) from canine embryonic fibroblasts, and a novel protocol for creating mature megakaryocytes (MKs) and functional platelets from ciPSCs. The ciPSCs were generated using lentiviral vectors, and differentiated into MKs and platelets on OP9 stromal cells supplemented with growth factors. Our ciPSCs presented in a tightly domed shape and showed expression of a critical pluripotency marker, REX1, and normal karyotype. Additionally, ciPSCs differentiated into cells derived from three germ layers via the formation of an embryoid body. The MKs derived from ciPSCs had hyperploidy and transformed into proplatelets. The proplatelets released platelets early on that expressed specific MK and platelet marker CD41/61. Interestingly, these platelets, when activated with adenosine diphosphate or thrombin, bind to fibrinogen. Moreover, electron microscopy showed that the platelets had the same ultrastructure as peripheral platelets. Thus, we have demonstrated for the first time the generation of ciPSCs that are capable of differentiating into MKs and release functional platelets in vitro. Our system for differentiating ciPSCs into MKs and platelets promises a critical therapy for canine TTP and appears to be extensible in principle to resolve human TTP.

  11. Single-platelet nanomechanics measured by high-throughput cytometry

    Science.gov (United States)

    Myers, David R.; Qiu, Yongzhi; Fay, Meredith E.; Tennenbaum, Michael; Chester, Daniel; Cuadrado, Jonas; Sakurai, Yumiko; Baek, Jong; Tran, Reginald; Ciciliano, Jordan C.; Ahn, Byungwook; Mannino, Robert G.; Bunting, Silvia T.; Bennett, Carolyn; Briones, Michael; Fernandez-Nieves, Alberto; Smith, Michael L.; Brown, Ashley C.; Sulchek, Todd; Lam, Wilbur A.

    2016-10-01

    Haemostasis occurs at sites of vascular injury, where flowing blood forms a clot, a dynamic and heterogeneous fibrin-based biomaterial. Paramount in the clot's capability to stem haemorrhage are its changing mechanical properties, the major drivers of which are the contractile forces exerted by platelets against the fibrin scaffold. However, how platelets transduce microenvironmental cues to mediate contraction and alter clot mechanics is unknown. This is clinically relevant, as overly softened and stiffened clots are associated with bleeding and thrombotic disorders. Here, we report a high-throughput hydrogel-based platelet-contraction cytometer that quantifies single-platelet contraction forces in different clot microenvironments. We also show that platelets, via the Rho/ROCK pathway, synergistically couple mechanical and biochemical inputs to mediate contraction. Moreover, highly contractile platelet subpopulations present in healthy controls are conspicuously absent in a subset of patients with undiagnosed bleeding disorders, and therefore may function as a clinical diagnostic biophysical biomarker.

  12. [Indications and surveillance of platelet transfusions in surgery].

    Science.gov (United States)

    Coffe, C; Bardiaux, L; Couteret, Y; Devillers, M; Leroy, M; Morel, P; Pouthier-Stein, F; Hervé, P

    1995-01-01

    Surgery, after hematology, is the biggest consumer of homologous platelet concentrates. Platelet transfusion is indicated to prevent or control bleeding associated with deficiencies in platelet number or function. In surgery, general patterns (in function of pre-surgery platelet count) can be adopted in most of the indications for platelets. In emergency situations, and in some particular cases (related to the patient, the type of operation, etc.), the transfusion procedure depends on the team's experience, the results of the available clinical and biological tests, and the drugs. Strict monitoring is required during the transfusion procedure. The efficacy of the transfusion must be controlled 1 h and 24 hours after the transfusion, and a number of factors must be assessed, namely the immunological impact of the transfusion (on red blood cells, leukocytes and platelets) and the occurrence of infectious diseases transmitted via transfusion. In addition, for a possible future transfusion, a strategy must be proposed.

  13. ROLE OF PLATELET TRANSFUSIONS IN DENGUE HEMORRHAGIC FEVER- 6 MONTHS REPORT

    Directory of Open Access Journals (Sweden)

    Geeta

    2012-08-01

    Full Text Available ABSTRACT: BACKGROUND: Allogenic platelet transfusion plays a major role in the management of thrombocytopenia. The study includes details of pla telet transfusion over a period of 6 months from January-2011 to June-2011 at blood bank of Gan dhi Hospital. Total number of patients who received were 487 and proportionate use of total un its of RDP (Random Donor Platelets issued from blood bank were as follows; dengue hemorrhagic fever (38% and remaining for acute leukemia (12%, Aplastic anemia (10%, sepsis (10% , DIC (Disseminated Intravascular Coagulation (10%, cardiac surgery (10%. In dengu e hemorrhagic fever, correlation of platelet count with platelet transfusion and platelet increm ent have been evaluated.

  14. The functional role of platelets in the regulation of angiogenesis.

    Science.gov (United States)

    Walsh, Tony G; Metharom, Pat; Berndt, Michael C

    2015-01-01

    Functionally, platelets are primarily recognized as key regulators of thrombosis and hemostasis. Upon vessel injury, the typically quiescent platelet interacts with subendothelial matrix to regulate platelet adhesion, activation and aggregation, with subsequent induction of the coagulation cascade forming a thrombus. Recently, however, newly described roles for platelets in the regulation of angiogenesis have emerged. Platelets possess an armory of pro- and anti-angiogenic proteins, which are actively sequestered and highly organized in α-granule populations. Platelet activation facilitates their release, eliciting potent angiogenic responses through mechanisms that appear to be tightly regulated. In conjunction, the release of platelet-derived phospholipids and microparticles has also earned merit as synergistic regulators of angiogenesis. Consequently, platelets have been functionally implicated in a range of angiogenesis-dependent processes, including physiological roles in wound healing, vascular development and blood/lymphatic vessel separation, whilst facilitating aberrant angiogenesis in a range of diseases including cancer, atherosclerosis and diabetic retinopathy. Whilst the underlying mechanisms are only starting to be elucidated, significant insights have been established, suggesting that platelets represent a promising therapeutic strategy in diseases requiring angiogenic modulation. Moreover, anti-platelet therapies targeting thrombotic complications also exert protective effects in disorders characterized by persistent angiogenesis.

  15. Heat shock protein 70 regulates platelet integrin activation, granule secretion and aggregation.

    Science.gov (United States)

    Rigg, Rachel A; Healy, Laura D; Nowak, Marie S; Mallet, Jérémy; Thierheimer, Marisa L D; Pang, Jiaqing; McCarty, Owen J T; Aslan, Joseph E

    2016-04-01

    Molecular chaperones that support protein quality control, including heat shock protein 70 (Hsp70), participate in diverse aspects of cellular and physiological function. Recent studies have reported roles for specific chaperone activities in blood platelets in maintaining hemostasis; however, the functions of Hsp70 in platelet physiology remain uninvestigated. Here we characterize roles for Hsp70 activity in platelet activation and function. In vitro biochemical, microscopy, flow cytometry, and aggregometry assays of platelet function, as well as ex vivo analyses of platelet aggregate formation in whole blood under shear, were carried out under Hsp70-inhibited conditions. Inhibition of platelet Hsp70 blocked platelet aggregation and granule secretion in response to collagen-related peptide (CRP), which engages the immunoreceptor tyrosine-based activation motif-bearing collagen receptor glycoprotein VI (GPVI)-Fc receptor-γ chain complex. Hsp70 inhibition also reduced platelet integrin-αIIbβ3 activation downstream of GPVI, as Hsp70-inhibited platelets showed reduced PAC-1 and fibrinogen binding. Ex vivo, pharmacological inhibition of Hsp70 in human whole blood prevented the formation of platelet aggregates on collagen under shear. Biochemical studies supported a role for Hsp70 in maintaining the assembly of the linker for activation of T cells signalosome, which couples GPVI-initiated signaling to integrin activation, secretion, and platelet function. Together, our results suggest that Hsp70 regulates platelet activation and function by supporting linker for activation of T cells-associated signaling events downstream of platelet GPVI engagement, suggesting a role for Hsp70 in the intracellular organization of signaling systems that mediate platelet secretion, "inside-out" activation of platelet integrin-αIIbβ3, platelet-platelet aggregation, and, ultimately, hemostatic plug and thrombus formation.

  16. Transcellular lipoxygenase metabolism between monocytes and platelets

    Energy Technology Data Exchange (ETDEWEB)

    Bigby, T.D.; Meslier, N. (Univ. of California, San Francisco (USA))

    1989-09-15

    We have examined the effects of co-culture and in vitro co-stimulation on lipoxygenase metabolism in monocytes and platelets. Monocytes were obtained from the peripheral blood of normal volunteers by discontinuous gradient centrifugation and adherence to tissue culture plastic. Platelets were obtained from the platelet-rich plasma of the same donor. When 10(9) platelets and 2.5 x 10(6) monocytes were co-stimulated with 1 microM A23187, these preparations released greater quantities of 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid, 5(S),12-(S)dihydroxy-6,10-trans-8,14-cis-eicosatetraenoic acid, and leukotriene C4, 5(S)-hydroxy-6(R)-S-glutathionyl-7,9-trans-11,14-cis-eicosatetraenoic (LTC4) when compared with monocytes alone. Release of arachidonic acid, 5-HETE, delta 6-trans-LTB4, and delta 6-trans-12-epi-LTB4 from monocytes was decreased in the presence of platelets. A dose-response curve was constructed and revealed that the above changes became evident when the platelet number exceeded 10(7). Dual radiolabeling experiments with 3H- and 14C-arachidonic acid revealed that monocytes provided arachidonic acid, 5-HETE, and LTA4 for further metabolism by the platelet. Monocytes did not metabolize platelet intermediates detectably. In addition, as much as 1.2 microM 12(S)-hydroxy-10-trans-5,8,14-cis-eicosatetraenoic acid and 12(S)-hydroperoxy-10-trans-5,8,14-cis-eicosatetraenoic acid had no effect on monocyte lipoxygenase metabolism. Platelets were capable of converting LTA4 to LTC4, but conversion of LTA4 to LTB4 was not detected. We conclude that the monocyte and platelet lipoxygenase pathways undergo a transcellular lipoxygenase interaction that differs from the interaction of the neutrophil and platelet lipoxygenase pathways. In this interaction monocytes provide intermediate substrates for further metabolic conversion by platelets in an unidirectional manner.

  17. Influence of Cardiopulmonary Bypass on the Interaction of Recombinant Factor VIIa with Activated Platelets

    OpenAIRE

    Kjalke, Marianne; Runge, Marx; Rojkjaer, Rasmus; Steinbruchel, Daniel; Johansson, Pär I

    2009-01-01

    Recombinant factor VIIa (rFVIIa) interacts preferentially with coated platelets characterized by a high exposure of phosphatidyl serine (PS), FV, FVIII, FIX, and FX binding, and fibrinogen. Cardiopulmonary bypass (CPB) is known to impair platelet function. In this study, the influence of CPB on formation of coated platelets and the interaction of rFVIIa with the platelets were studied. Blood was either exposed to a closed CPB circuit or obtained from patients undergoing CPB-assisted cardiac s...

  18. miR-326 Targets Antiapoptotic Bcl-xL and Mediates Apoptosis in Human Platelets

    OpenAIRE

    Shifang Yu; Huicong Huang; Gang Deng; Zuoting Xie; Yincai Ye; Ruide Guo; Xuejiao Cai; Junying Hong; Dingliang Qian; Xiangjing Zhou; Zhihua Tao; Bile Chen; Qiang Li

    2015-01-01

    Platelets play crucial roles in hemostasis, thrombosis, wound healing, inflammation, angiogenesis, and tumor metastases. Because they are anucleated blood cells, platelets lack nuclear DNA, but they do contain mitochondrial DNA, which plays a key role in regulating apoptosis. Recent evidence has suggested that miRNAs are also involved in regulating gene expression and apoptosis in platelets. Our previous study showed that the expression of miR-326 increased visibly when apheresis platelets we...

  19. Full-facial rejuvenation with autologous platelet-derived growth factors

    OpenAIRE

    2012-01-01

    The platelets used in oral, maxillofacial and plastic surgery are generally grouped as concentrated platelet rich plasma. The general principle of production consists of a centrifugation, making it possible to eliminate red blood cells, then acellular plasma, to preserve only the concentrated platelets. Aim to evaluate the efficacy of a three session of injections of autologous platelet-derived growth factors for full-face rejuvenation including the perioral and periorbital regions; 16 patien...

  20. Monocyte-Platelet Interaction Induces a Pro-Inflammatory Phenotype in Circulating Monocytes

    OpenAIRE

    2011-01-01

    BACKGROUND: Activated platelets exert a pro-inflammatory action that can be largely ascribed to their ability to interact with leukocytes and modulate their activity. We hypothesized that platelet activation and consequent formation of monocyte-platelet aggregates (MPA) induces a pro-inflammatory phenotype in circulating monocytes. METHODOLOGY/PRINCIPAL FINDINGS: CD62P(+) platelets and MPA were measured, and monocytes characterized, by whole blood flow cytometry in healthy subjects, before an...

  1. The long-term effects of pitavastatin on blood lipids and platelet activation markers in stroke patients: impact of the homocysteine level.

    Directory of Open Access Journals (Sweden)

    Hideki Sugimoto

    Full Text Available To examine the impact of the plasma homocysteine level on the anti-atherosclerotic effects of pitavastatin treatment, we retrospectively examined 59 patients who had a history of stroke and had been prescribed pitavastatin for the treatment of dyslipidemia at the Neurology department of Toho University Ohashi Medical Center Hospital. The patients were classified into two groups according to their homocysteine levels. Carotid artery plaque progression was determined before and after pitavastatin treatment. Plasma levels of high-sensitivity C-reactive protein, platelet molecular markers, and von Willebrand factor were measured. Pitavastatin treatment had beneficial effects on the lipid profiles of these patients and slowed atherosclerosis progression. These effects were observed in both the high and low homocysteine groups. Proactive lipid intervention using pitavastatin may inhibit the progression of atherosclerosis and contribute to secondary prevention of stroke in high-risk patients. We conclude that this statin could inhibit progression at any stage of disease and should therefore be proactively administered to these patient groups, regardless of disease severity.

  2. Cellular origin of platelet-derived microparticles in vivo

    NARCIS (Netherlands)

    A. Rank; R. Nieuwland; R. Delker; A. Köhler; B. Toth; V. Pihusch; R. Wilkowski; R. Pihusch

    2010-01-01

    Introduction: Microparticles (MP), presumably of platelet origin, are the most abundant microparticles in blood. To which extent such MP may also directly originate from megakaryocytes, however, is unknown. During hematopoietic stem cell transplantation, patients undergo total body irradiation which

  3. Platelet serotonin transporter function predicts default-mode network activity.

    Directory of Open Access Journals (Sweden)

    Christian Scharinger

    Full Text Available The serotonin transporter (5-HTT is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence.A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (Vmax was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD activity and platelet Vmax.The present study demonstrates that increases in platelet Vmax significantly predict default-mode network (DMN suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet Vmax is related to global DMN activation and not intrinsic DMN connectivity.This study provides evidence that platelet Vmax predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal Vmax coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.

  4. Effect on umbilical cord blood platelet - rich plasma promoting proliferation of umbilical cord blood mesenchymal stem cells%脐血来源富血小板血浆对脐血间充质干细胞增殖的影响

    Institute of Scientific and Technical Information of China (English)

    胡资兵; 孙杰聪; 刘田丰

    2016-01-01

    Objective To explore the best concentration of umbilical cord blood derived platelet rich plasma for promoting the proliferation and proliferation of umbilical cord blood mesenchymal stem cells. Method Umbilical cord blood was collected in term health cesarean selection newborn. Separation of umbilical cord blood mesenchymal stem cells was performed by using the tissue pieces culture. Platelet - rich plasma from umbilical cord blood was extracted with the use of secondary centrifuga-tion. Transforming growth factor - beta 1 in platelet - rich plasma was detected with the method of ELISA. In this experiment, platelet rich plasma combined 10% fetal bovine serum was used to cultivate umbilical cord blood mesenchymal stem cells. According to the concentration of TGF - beta 1 in platelet - rich plasma,the experiment was divided into 6 groups:2 000 pg/ ml,1 000 pg/ ml,750 pg/ ml,500 pg/ ml,250 pg/ ml,10% fetal bovine serum group. Umbilical cord blood mesenchy-mal stem cells were incubated in 96 - well plates,and cultured for 7 days. After 1,3,5,and 7 days later,CCK8 kit was used to determinate the proliferation effect of mesenchymal stem cells. Meanwhile,statistical analysis was performed to select the best concentration. Results Different concentrations of platelet - rich plasma combined 10% fetal bovine serum resulted in varied proliferation rate from umbilical cord blood mesenchymal stem cells. The findings suggested that the proliferation rate in 500 ~1 000 pg/ ml concentration groups was superior to that of other groups. It was not 5 - day cultured until there was statistically significant(P ﹤ 0. 05). Conclusion Platelet - rich plasma can improve proliferation of the umbilical cord blood mesenchymal stem cells. Furthermore,the activity shows a dose dependent.%目的:初步探讨脐血来源富血小板血浆促进脐血间充质干细胞增殖及增殖最佳浓度。方法:收集足月健康剖宫产新生儿脐带血,采用组织块培养法进行脐血间

  5. Effects of local application of platelet-rich plasma and guided tissue regeneration on stability of implants

    OpenAIRE

    Duka Miloš; Lazić Z.; Bubalo Marija; Tatić Z.; Đurđević D.; Matić Smiljana

    2010-01-01

    Osseointegration is a result of cellular migration, differentiation, bone formation, and bone remodelling on the surface of an implant. Each of these processes depends on platelets and blood coagulum. Platelet-rich plasma (PRP) is used to improve osseointegration and stability of implants. It is a blood fraction produced in a centrifuge which contains a high concentration of platelets. Platelets contain numerous growth factors which influence tissue reactions. The aim of the research is to te...

  6. EVALUATION OF PLATELET COUNTS AND PLATELET INDICES AND THEIR SIGNIFICANT ROLE IN PRE-ECLAMPSIA AND ECLAMPSIA

    Directory of Open Access Journals (Sweden)

    Vijaya

    2014-03-01

    Full Text Available BACKGROUND: Preeclampsia and eclampsia are the most leading cause of maternal mortality in developing countries like ours. The aim of our study is to find out the relation between platelet indices and platelet counts with preeclampsia and eclampsia and their significance as prognostic indicator. MATERIALS AND METHOD: 82 cases of preeclampsia and 63 cases of eclampsia diagnosed between September 2010 to December 2013 were evaluated prospectively. One hundred healthy pregnant women with similar demographic features and gestational age without diagnosis of preeclampsia were included in the study of control group. Blood samples were analyzed by automated hematology analyzer. The platelet count, mean platelet volume and platelet distribution width were compared. RESULTS: The platelet counts were lower while mean platelet volume, platelet distribution width were increased in preeclampsia and eclampsia as compared to control group. CONCLUSION: We found an association between platelet indices and severity of preeclampsia. The estimation of platelet indices can be considered as an early, simple and rapid procedure in the assessment of severity of preeclampsia and eclampsia which can be used as a prognostic marker.

  7. Application of the extended nursing care in blood donors after the first apheresis platelet col ection%延续护理在首次单采血小板后献血者中的应用

    Institute of Scientific and Technical Information of China (English)

    龙雪芳; 卢丽霞; 黎添华; 梁静仪; 赖许肖

    2016-01-01

    Objective:To explore the application of the extended nursing care in blood donors after the first apheresis platelet collection. Methods:120 blood donors were randomly divided into the observation group and the control group(60 donors in each group),the routine nursing care was given to the donors in the control group and the extra extended nursing care was provided in the observation group,the change of thrombopoietin and platelet activating factor,life quality and satisfaction of the donors were compared between the two groups. Results:There were statistically significant differences in the comparison of the change of thrombopoietin and platelet activating factor be-tween the two groups before and after the intervention(P ﹤ 0. 05);the scores of life quality of the donors were superior in the observation group to the control group(P ﹤ 0. 01). Conclusion:The extended nursing care can relieve the psychological concerns of blood donors and improve their safety.%目的:探讨延续护理在首次单采血小板后献血者中的应用。探讨延续护理对首次单采血小板后献血者血小板生成素与血小板活化因子的影响。方法:将120名首次单采血小板献血者随机分为观察组和对照组各60名。对照组采用常规护理方式,观察组在此基础上采用延续护理模式,比较两组血小板生成素、血小板活化因子变化情况、干预后生活质量及服务满意度。结果:观察组干预前后血小板生成素及血小板活化因子变化比较差异有统计学意义( P ﹤0.05),观察组生活质量评分优于对照组(P ﹤0.01);观察组满意度较高。结论:通过延续护理可提高献血者献血安全,不会引起献血者的身体伤害,解除献血者心理顾虑,对招募起积极作用。

  8. Comparison of TGF and PDGF Levels in Platelet Rich Plasma Extracted From the Blood and Venous Blood of Fracture%骨折断端血与静脉血提取的富血小板血浆中TGF及PDGF含量比较

    Institute of Scientific and Technical Information of China (English)

    赫兰学; 马震卓; 丁雪峰; 李建杰

    2016-01-01

    Objective To analysis of fracture end and venous blood from the blood platelet rich plasma TGF and PDGF content. Methods 11 big white rabbit as experimental object,take the blood of fracture end,as the experimental group,7 venous blood was taken as the control group randomly. The same method to extract the PRP,compare two groups of PDGF and TGF-beta content in PRP. Results The extraction of TGF PRP of fracture end blood and PDGF were higher than in venous blood extract concentration of PRP TGF and PDGF. Conclusion Extracted from the fracture end blood PRP PDGF and TGF-beta content is higher than that of venous blood in PRP.%目的:分析骨折断端血与静脉血提取的富血小板血浆中TGF及PDGF含量。方法将11只大白兔作为实验对象,取骨折断端血,为实验组,随机抽取7只采取静脉血作为对照组。相同方法提取PRP,比较两组PRP中的PDGF及TGF-β含量。结果骨折断端血提取的PRP中的TGF与PDGF均高于静脉血提取PRP中的TGF与PDGF浓度。结论从骨折断端血中提取的PRP中的PDGF及TGF-β含量高于静脉血PRP。

  9. Clopidogrel resistance of patients with coronary artery disease and its correlation with platelet count and mean platelet volume

    Institute of Scientific and Technical Information of China (English)

    李蕾

    2013-01-01

    Objective To explore the association between clopidogrel resistance(CR)as assessed by whole blood electrical impedance aggregometry(EIA) and platelet parameters.Methods The prospective study comprised 152 patients

  10. Platelet receptor expression and shedding: glycoprotein Ib-IX-V and glycoprotein VI.

    Science.gov (United States)

    Gardiner, Elizabeth E; Andrews, Robert K

    2014-04-01

    Quantity, quality, and lifespan are 3 important factors in the physiology, pathology, and transfusion of human blood platelets. The aim of this review is to discuss the proteolytic regulation of key platelet-specific receptors, glycoprotein(GP)Ib and GPVI, involved in the function of platelets in hemostasis and thrombosis, and nonimmune or immune thrombocytopenia. The scope of the review encompasses the basic science of platelet receptor shedding, practical aspects related to laboratory analysis of platelet receptor expression/shedding, and clinical implications of using the proteolytic fragments as platelet-specific biomarkers in vivo in terms of platelet function and clearance. These topics can be relevant to platelet transfusion regarding both changes in platelet receptor expression occurring ex vivo during platelet storage and/or clinical use of platelets for transfusion. In this regard, quantitative analysis of platelet receptor profiles on blood samples from individuals could ultimately enable stratification of bleeding risk, discrimination between causes of thrombocytopenia due to impaired production vs enhanced clearance, and monitoring of response to treatment prior to change in platelet count.

  11. A novel inflammatory role for platelets in sickle cell disease.

    Science.gov (United States)

    Davila, Jennifer; Manwani, Deepa; Vasovic, Ljiljana; Avanzi, Mauro; Uehlinger, Joan; Ireland, Karen; Mitchell, W Beau

    2015-01-01

    The severe pain, ischemia and organ damage that characterizes sickle cell disease (SCD) is caused by vaso-occlusion, which is the blockage of blood vessels by heterotypic aggregates of sickled erythrocytes and other cells. Vaso-occlusion is also a vasculopathy involving endothelial cell dysfunction, leukocyte activation, platelet activation and chronic inflammation resulting in the multiple adhesive interactions between cellular elements. Since platelets mediate inflammation as well as thrombosis via release of pro- and anti-inflammatory molecules, we hypothesized that platelets may play an active inflammatory role in SCD by secreting increased amounts of cytokines. Since platelets have been shown to contain mRNA and actively produce proteins, we also hypothesized that SCD platelets may contain increased cytokine mRNA. In this cross-sectional study, we sought to compare both the quantity of cytokines secreted and the cytokine mRNA content, between SCD and control platelets. We measured the secretion of Th1, Th2, and Th17-related cytokines from platelets in a cohort of SCD patients. We simultaneously measured platelet mRNA levels of those cytokines. Platelets from SCD patients secreted increased quantities of IL-1β, sCD40L, and IL-6 compared to controls. Secretion was increased in patients with alloantibodies. Additionally, mRNA of those cytokines was increased in SCD platelets. Platelets from sickle cell patients secrete increased amounts of inflammatory cytokines, and contain increased cytokine mRNA. These findings suggest a novel immunological role for platelets in SCD vasculopathy, in addition to their thrombotic role, and strengthen the rationale for the use of anti-platelet therapy in SCD.

  12. Selective inhibition of the platelet phosphoinositide 3-kinase p110beta as promising new strategy for platelet protection during extracorporeal circulation.

    Science.gov (United States)

    Straub, Andreas; Wendel, Hans Peter; Dietz, Klaus; Schiebold, Daniela; Peter, Karlheinz; Schoenwaelder, Simone M; Ziemer, Gerhard

    2008-03-01

    Extracorporeal circulation (ECC) is used in cardiac surgery for cardiopulmonary bypass as well as in ventricular assist devices and for extracorporeal membrane oxygenation. Blood contact with the artificial surface and shear stress of ECC activates platelets and leukocytes resulting in a coagulopathy and proinflammatory events. Blockers of the platelet glycoprotein (GP) IIb/IIIa (CD41/CD61) can protect platelet function during ECC, a phenomenon called "platelet anaesthesia", but may be involved in post-ECC bleeding. We hypothesized that the new selective phosphoinositide 3-kinase p110beta inhibitor TGX-221 that inhibits shear-induced platelet activation without prolonging the bleeding time in vivo may also protect platelet function during ECC. Heparinized blood of healthy volunteers (n = 6) was treated in vitro with either the GP IIb/IIIa blocker tirofiban, TGX-221 or as control and circulated in an ECC model. Before and after 30 minutes circulation CD41 expression on the ECC-tubing as measure for platelet-ECC binding and generation of the platelet activation marker beta-thromboglobulin were determined using ELISA. Platelet aggregation and platelet-granulocyte binding were analysed in flow cytometry. After log-transforming the data statistical evaluation was performed using multifactor ANOVA in combination with Tukey's HSD test (global alpha = 5%). Tirofiban and TGX-221 inhibited platelet-ECC interaction, platelet aggregation and platelet-granulocyte binding. Tirofiban also inhibited ECC-induced beta-thromboglobulin release. The observed inhibition of platelet-ECC interaction and platelet activation by tirofiban contributes to explain the mechanism of "platelet anaesthesia". TGX-221 represents a promising alternative to GP IIb/IIIa blockade and should be further investigated for use during ECC in vivo.

  13. Dengue virus binding and replication by platelets.

    Science.gov (United States)

    Simon, Ayo Y; Sutherland, Michael R; Pryzdial, Edward L G

    2015-07-16

    Dengue virus (DENV) infection causes ∼200 million cases of severe flulike illness annually, escalating to life-threatening hemorrhagic fever or shock syndrome in ∼500,000. Although thrombocytopenia is typical of both mild and severe diseases, the mechanism triggering platelet reduction is incompletely understood. As a probable initiating event, direct purified DENV-platelet binding was followed in the current study by quantitative reverse transcription-polymerase chain reaction and confirmed antigenically. Approximately 800 viruses specifically bound per platelet at 37°C. Fewer sites were observed at 25°C, the blood bank storage temperature (∼350 sites), or 4°C, known to attenuate virus cell entry (∼200 sites). Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) and heparan sulfate proteoglycan were implicated as coreceptors because only the combination of anti-DC-SIGN and low-molecular-weight heparin prevented binding. Interestingly, at 37°C and 25°C, platelets replicated the positive sense single-stranded RNA genome of DENV by up to ∼4-fold over 7 days. Further time course experiments demonstrated production of viral NS1 protein, which is known to be highly antigenic in patient serum. The infectivity of DENV intrinsically decayed in vitro, which was moderated by platelet-mediated generation of viable progeny. This was shown using a transcription inhibitor and confirmed by freeze-denatured platelets being incapable of replicating the DENV genome. For the first time, these data demonstrate that platelets directly bind DENV saturably and produce infectious virus. Thus, expression of antigen encoded by DENV is a novel consideration in the pathogen-induced thrombocytopenia mechanism. These results furthermore draw attention to the possibility that platelets may produce permissive RNA viruses in addition to DENV.

  14. Investigation of platelet margination phenomena at elevated shear stress.

    Science.gov (United States)

    Zhao, Rui; Kameneva, Marina V; Antaki, James F

    2007-01-01

    Thrombosis is a common complication following the surgical implantation of blood contacting artificial organs. Platelet transport, which is an important process of thrombosis and strongly modulated by flow dynamics, has not been investigated under the shear stress level associated with these devices, which may range from tens to several hundred Pascal.The current research investigated platelet transport within blood under supra-physiological shear stress conditions through a micro flow visualization approach. Images of platelet-sized fluorescent particles in the blood flow were recorded within microchannels (2 cm x 100 microm x 100 microm). The results successfully demonstrated the occurrence of platelet-sized particle margination under shear stresses up to 193 Pa, revealing a platelet near-wall excess up to 8.7 near the wall (within 15 microm) at the highest shear stress. The concentration of red blood cells was found to influence the stream-wise development of platelet margination which was clearly observed in the 20% Ht sample but not the 40% Ht sample. Shear stress had a less dramatic effect on the margination phenomenon than did hematocrit. The results imply that cell-cell collision is an important factor for platelet transport under supra-physiologic shear stress conditions. It is anticipated that these results will contribute to the future design and optimization of artificial organs.

  15. Diagnostic usefulness of thrombus imaging scintigraphy for blood coagulopathy in the patients with aortic aneurysm. The comparison of /sup 111/In-oxine labelled platelet and sup(99m)Tc-fibrinogen scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Sakakibara, Yuzuru; Takeda, Toru; Ijima, Hiroshi; Nose, Tadao; Ishikawa, Nobuyoshi; Hori, Motokazu

    1984-07-01

    Eighteen patients with aortic aneurysm were studied to identify intraluminal thrombi using /sup 111/In-oxine labelled platelet and /sup 99m/Tc-fibrinogen scintigraphy. Reliability in the detection of thrombi with /sup 111/In-oxine labelled platelet scintigraphy was higher than that with /sup 99m/Tc-fibrinogen scintigraphy (94.1% vs 76.9%, respectively). Measurement of mean platelet survival time with /sup 111/In-oxine labelled autologous platelets were carried out in eight patients. Seven of them showed focal accumulation of the labelled platelets at the site of aortic aneurysm and mean platelet survival time (6.64 + 1.46 days) was shorter than normal. In the case of abdominal aneurysm, thrombocytopenia was present, his mean platelet survival time was 4.01 days and RI was accumulated at the site of aneurysm. His hematological pathophysiology could be explained as consumption coagulopathy in the abdominal aneurysm. Using scanning electron-microscopy, we found entrapped platelets with fine fibrin network were found indicating platelet consumption at the site of intraluminal thrombi. It was concluded that these imaging techniques using radioisotopes were very useful not only for detecting intraluminal thrombi but for diagnosing consumption coagulopathy and disseminated intravascular coagulation even where there is no clinical manifestation.

  16. Comparison of cytotoxic and anti-platelet activities of polyphenolic extracts from Arnica montana flowers and Juglans regia husks.

    Science.gov (United States)

    Rywaniak, Joanna; Luzak, Boguslawa; Podsedek, Anna; Dudzinska, Dominika; Rozalski, Marcin; Watala, Cezary

    2015-01-01

    Polyphenolic compounds of plant origin are well known to be beneficial to human health: they exert protective effects on haemostasis and have a particular influence on blood platelets. However, the anti-platelet properties of polyphenolic compounds observed so far have not been weighed against their potential cytotoxic action against platelets. The aim of this study was to demonstrate that anti-platelet and cytotoxic effects on blood platelets may interfere and therefore, may often lead to confusion when evaluating the properties of plant extracts or other agents towards blood platelets. The anti-platelet and cytotoxic in vitro effects of plant extracts obtained from the husks of walnuts (J. regia) and flowers of arnica (A. montana) on platelet reactivity and viability were examined. Platelet function was assessed using standard methods (flow cytometry: P-selectin expression, activation of GPIIbIIIa complex, vasodilator-stimulated phosphoprotein, VASP index; turbidimetric and impedance aggregometry) and newly set assays (flow cytometric monitoring of platelet cytotoxicity). The results reveal that none of the studied plant extracts demonstrated cytotoxicity towards blood platelets. The phenolic acid-rich extract of A. montana (7.5 and 15 µg/ml) significantly reduced the ADP-induced aggregation in both whole blood and PRP, and decreased the platelet reactivity index (PRI; VASP phosphorylation) in whole blood, while showing excellent antioxidant capacity. The extract of J. regia husks significantly reduced ADP-induced platelet aggregation in whole blood when applied at 7.5 µg/ml, and only slightly decreased the PRI at 15 µg/ml. Both examined extracts suppressed platelet hyper-reactivity, and such influence did not interfere with cytotoxic effects of the extracts. Thus, its high polyphenol content, excellent antioxidant capacity and distinct anti-platelet properties, in combination with its lack of toxicity, make the extract of A. montana flowers a possible

  17. In vitro platelet activation, aggregation and platelet-granulocyte complex formation induced by surface modified single-walled carbon nanotubes.

    Science.gov (United States)

    Fent, János; Bihari, Péter; Vippola, Minnamari; Sarlin, Essi; Lakatos, Susan

    2015-08-01

    Surface modification of single-walled carbon nanotubes (SWCNTs) such as carboxylation, amidation, hydroxylation and pegylation is used to reduce the nanotube toxicity and render them more suitable for biomedical applications than their pristine counterparts. Toxicity can be manifested in platelet activation as it has been shown for SWCNTs. However, the effect of various surface modifications on the platelet activating potential of SWCNTs has not been tested yet. In vitro platelet activation (CD62P) as well as the platelet-granulocyte complex formation (CD15/CD41 double positivity) in human whole blood were measured by flow cytometry in the presence of 0.1mg/ml of pristine or various surface modified SWCNTs. The effect of various SWCNTs was tested by whole blood impedance aggregometry, too. All tested SWCNTs but the hydroxylated ones activate platelets and promote platelet-granulocyte complex formation in vitro. Carboxylated, pegylated and pristine SWCNTs induce whole blood aggregation as well. Although pegylation is preferred from biomedical point of view, among the samples tested by us pegylated SWCNTs induced far the most prominent activation and a well detectable aggregation of platelets in whole blood.

  18. Duration of exposure to high fluid shear stress is critical in shear-induced platelet activation-aggregation.

    Science.gov (United States)

    Zhang, Jian-ning; Bergeron, Angela L; Yu, Qinghua; Sun, Carol; McBride, Latresha; Bray, Paul F; Dong, Jing-fei

    2003-10-01

    Platelet functions are increasingly measured under flow conditions to account for blood hydrodynamic effects. Typically, these studies involve exposing platelets to high shear stress for periods significantly longer than would occur in vivo. In the current study, we demonstrate that the platelet response to high shear depends on the duration of shear exposure. In response to a 100 dyn/cm2 shear stress for periods less than 10-20 sec, platelets in PRP or washed platelets were aggregated, but minimally activated as demonstrated by P-selectin expression and binding of the activation-dependent alphaIIbbeta3 antibody PAC-1 to sheared platelets. Furthermore, platelet aggregation under such short pulses of high shear was subjected to rapid disaggregation. The disaggregated platelets could be re-aggregated by ADP in a pattern similar to unsheared platelets. In comparison, platelets that are exposed to high shear for longer than 20 sec are activated and aggregated irreversibly. In contrast, platelet activation and aggregation were significantly greater in whole blood with significantly less disaggregation. The enhancement is likely via increased collision frequency of platelet-platelet interaction and duration of platelet-platelet association due to high cell density. It may also be attributed to the ADP release from other cells such as red blood cells because increased platelet aggregation in whole blood was partially inhibited by ADP blockage. These studies demonstrate that platelets have a higher threshold for shear stress than previously believed. In a pathologically relevant timeframe, high shear alone is likely to be insufficient in inducing platelet activation and aggregation, but acts synergistically with other stimuli.

  19. Platelets miRNA as a Prediction Marker of Thrombotic Episodes

    Directory of Open Access Journals (Sweden)

    Michal Bijak

    2016-01-01

    Full Text Available The blood platelets are crucial for the coagulation physiology to maintain haemostatic balance and are involved in various pathologies such as atherosclerosis and thrombosis. The studies of recent years have shown that anucleated platelets are able to succeed protein synthesis. Additionally, mRNA translation in blood platelets is regulated by miRNA molecules. Recent works postulate the possibility of using miRNAs as biomarkers of atherosclerosis and ischemic episodes. This review article describes clinical studies that presented blood platelets miRNAs expression profile changes in different thrombotic states, which suggest use of these molecules as predictive biomarkers.

  20. Blood Donation Process

    Science.gov (United States)

    ... types, such as platelets, red cells or plasma ( apheresis donations ) can take up to 2 hours. When ... Disease Testing Reimbursement Resources Educational Resources PACS Therapeutic Apheresis Our Supporters Blood App HS Leadership Program SleevesUp ...

  1. Are Platelets Cells? And if Yes, Are They Immune Cells?

    Directory of Open Access Journals (Sweden)

    Fabrice eCOGNASSE

    2015-02-01

    Full Text Available Small fragments circulating in the blood were formally identified by the end of the 19th century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the 20th century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such however, they were acknowledged as immunizing (to specific HPA and HLA markers: the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as the 1930s, platelets entered the arsenal of medicines; were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an immune cell? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages. The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of

  2. Effects of Suilysin on Streptococcus suis-induced platelet aggregation

    Directory of Open Access Journals (Sweden)

    Shengwei Zhang

    2016-10-01

    Full Text Available Blood platelets play important roles during pathological thrombocytopenia in streptococcal toxic shock syndrome (STSS. Streptococcus suis (S. suis an emerging human pathogen, can cause STSS similarly to S. pyogenes. However, S. suis interactions with platelets are poorly understood. Here, we found that suilysin (SLY, different from other bacterial cholesterol-dependent cytolysins (CDCs, was the sole stimulus that induced platelet aggregation. Furthermore, the inside-out activation of GPIIb/IIIa of platelets mediated SLY-induced platelet aggregation. This process was triggered by Ca2+ influx that depend on the pore forming on platelets by SLY. Additionally, although SLY induced α-granule release occurred via the MLCK-dependent pathway, PLC-β-IP3/DAG-MLCK and Rho-ROCK-MLCK signaling were not involved in SLY-induced platelet aggregation. Interestingly, the pore dependent Ca2+ influx was also found to participate in the induction of platelet aggregation with pneumolysin (PLY and streptolysin O (SLO, two other CDCs. It is possible that the CDC-mediated platelet aggregation we observed in S. suis is a similar response mechanism to that used by a wide range of bacteria. These findings might lead to the discovery of potential therapeutic targets for S. suis-associated STSS.

  3. Effects of Suilysin on Streptococcus suis-Induced Platelet Aggregation

    Science.gov (United States)

    Zhang, Shengwei; Wang, Junping; Chen, Shaolong; Yin, Jiye; Pan, Zhiyuan; Liu, Keke; Li, Lin; Zheng, Yuling; Yuan, Yuan; Jiang, Yongqiang

    2016-01-01

    Blood platelets play important roles during pathological thrombocytopenia in streptococcal toxic shock syndrome (STSS). Streptococcus suis (S. suis) an emerging human pathogen, can cause STSS similarly to S. pyogenes. However, S. suis interactions with platelets are poorly understood. Here, we found that suilysin (SLY), different from other bacterial cholesterol-dependent cytolysins (CDCs), was the sole stimulus that induced platelet aggregation. Furthermore, the inside-out activation of GPIIb/IIIa of platelets mediated SLY-induced platelet aggregation. This process was triggered by Ca2+ influx that depend on the pore forming on platelets by SLY. Additionally, although SLY induced α-granule release occurred via the MLCK-dependent pathway, PLC-β-IP3/DAG-MLCK and Rho-ROCK-MLCK signaling were not involved in SLY-induced platelet aggregation. Interestingly, the pore dependent Ca2+ influx was also found to participate in the induction of platelet aggregation with pneumolysin (PLY) and streptolysin O (SLO), two other CDCs. It is possible that the CDC-mediated platelet aggregation we observed in S. suis is a similar response mechanism to that used by a wide range of bacteria. These findings might lead to the discovery of potential therapeutic targets for S. suis-associated STSS. PMID:27800304

  4. Radiation-induced volatile hydrocarbon production in platelets. Scientific report

    Energy Technology Data Exchange (ETDEWEB)

    Radha, E.; Vaishnav, Y.N.; Kumar, K.S.; Weiss, J.F.

    1989-01-01

    Thrombocytopenia plays an important role in the development of the post-irradiation hemorrhagic syndrome. Although destruction of platelet precursors in bone marrow is a major effect of high-dose radiation exposure, the effects of radiation on preformed platelets are unclear. The latter is also of concern with respect to blood-banking practices since platelets are often irradiated at doses in the range of 20-50 Gy before transfusions to prevent graft-versus-host disease. With increasing emphasis on allogenic and autologous bone-marrow transplantation, transfusions of irradiated platelets are likely to rise. Generation of volatile hydrocarbons (ethane, pentane) as a measure of lipid peroxidation was followed in preparations from platelet-rich plasma irradiated in vitro. The hydrocarbons in the headspace of sealed vials containing irradiated and nonirradiated washed platelets, platelet-rich plasma, or platelet-poor plasma increased with time. The major hydrocarbon, pentane, increased linearly and significantly with increasing log radiation dose, suggesting that reactive oxygen species induced by ionizing radiation result in lipid peroxidation. Measurements of lipid peroxidation products may give an indication of suboptimal quality of stored and/or irradiated platelets.

  5. Platelets protect lung from injury induced by systemic inflammatory response

    Science.gov (United States)

    Luo, Shuhua; Wang, Yabo; An, Qi; Chen, Hao; Zhao, Junfei; Zhang, Jie; Meng, Wentong; Du, Lei

    2017-01-01

    Systemic inflammatory responses can severely injure lungs, prompting efforts to explore how to attenuate such injury. Here we explored whether platelets can help attenuate lung injury in mice resulting from extracorporeal circulation (ECC)-induced systemic inflammatory responses. Mice were subjected to ECC for 30 min, then treated with phosphate-buffered saline, platelets, the GPIIb/IIIa inhibitor Tirofiban, or the combination of platelets and Tirofiban. Blood and lung tissues were harvested 60 min later, and lung injury and inflammatory status were assessed. As expected, ECC caused systemic inflammation and pulmonary dysfunction, and platelet transfusion resulted in significantly milder lung injury and higher lung function. It also led to greater numbers of circulating platelet-leukocyte aggregates and greater platelet accumulation in the lung. Platelet transfusion was associated with higher production of transforming growth factor-β and as well as lower levels of tumour necrosis factor-α and neutrophil elastase in plasma and lung. None of these platelet effects was observed in the presence of Tirofiban. Our results suggest that, at least under certain conditions, platelets can protect lung from injury induced by systemic inflammatory responses. PMID:28155889

  6. Enhancement by platelets of oxygen radical responses of human neutrophils

    Energy Technology Data Exchange (ETDEWEB)

    McCulloch, K.K.; Powell, J.; Johnson, K.J.; Ward, P.A.

    1986-03-01

    When human blood neutrophils were incubated with immune complexes (consisting of IgG antibody) in the presence of platelets, there was a 2 to 10 fold enhancement in the generation of O-/sub 2/ and H/sub 2/O/sub 2/. This enhancement phenomenon was proportional to the dose of immune complex added and the number of platelets present. The response was not agonist specific since similar enhancement also occurred with the following agonists: phorbol myristate acetate, opsonized zymosan particles and the chemotactic peptide N-formyl-met-leu-phe. The platelet related phenomenon of enhanced O-/sub 2/ generation could not be reproduced by the addition of serotonin, histamine or platelet-derived growth factor and was not affected by prior treatment of platelets with cyclooxygenase inhibitors (indomethacin, piroxicam) or lipoxygenase inhibitors (nafazatrom, BW755C or nordihydroguaiaretic acid). However, activation of platelets by thrombin caused release into the platelet supernatant fluid of a factor that, only in the presence of immune complexes, caused enhanced O-/sub 2/ responses to neutrophils. These data indicate that platelets potentiate oxygen radical responses of human neutrophils and suggest a mechanisms by which platelets may participate in tissue injury which is mediated by oxygen radical products from activated neutrophils.

  7. EDTA dependent pseudothrombocytopenia caused by antibodies against the cytoadhesive receptor of platelet gpIIB-IIIA.

    OpenAIRE

    1994-01-01

    AIMS--To clarify the mechanisms involved in the development of EDTA dependent pseudothrombocytopenia, particularly the platelet receptors. METHODS--Platelets were measured in 33 patients with pseudothrombocytopenia, using different anticoagulants to collect blood samples (direct test). The results were compared with the counts obtained by adding patients' serum or immunoglobulins to normal blood samples (indirect test). The role of platelet function was explored using ASA, PGE1, and apyrase a...

  8. The effects of ropivacaine hydrochloride on platelet function: an assessment using the platelet function analyser (PFA-100).

    LENUS (Irish Health Repository)

    Porter, J

    2012-02-03

    Amide local anaesthetics impair blood clotting in a concentration-dependent manner by inhibition of platelet function and enhanced fibrinolysis. We hypothesised that the presence of ropivacaine in the epidural space could decrease the efficacy of an epidural blood patch, as this technique requires that the injected blood can clot in order to be effective. Ropivacaine is an aminoamide local anaesthetic used increasingly for epidural analgesia during labour. The concentration of local anaesthetic in blood achieved in the epidural space during the performance of an epidural blood patch is likely to be the greatest which occurs (intentionally) in any clinical setting. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur: (i) clinically in the epidural space and (ii) in plasma during an epidural infusion of ropivacaine, alter platelet function. A platelet function analyser (Dade PFA-100, Miami) was employed to assess the effects of ropivacaine-treated blood on platelet function. The greater concentrations of ropivacaine studied (3.75 and 1.88 mg x ml(-1)), which correspond to those which could occur in the epidural space, produced significant inhibition of platelet aggregation. We conclude that the presence of ropivacaine in the epidural space may decrease the efficacy of an early or prophylactic epidural blood patch.

  9. A Novel Platelet Concentrate: Titanium-Prepared Platelet-Rich Fibrin

    Directory of Open Access Journals (Sweden)

    Mustafa Tunalı

    2014-01-01

    Full Text Available We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF. The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun’s leukocyte- and platelet-rich fibrin (L-PRF method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF was processed with a scanning electron microscope (SEM. The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

  10. A novel platelet concentrate: titanium-prepared platelet-rich fibrin.

    Science.gov (United States)

    Tunalı, Mustafa; Özdemir, Hakan; Küçükodacı, Zafer; Akman, Serhan; Yaprak, Emre; Toker, Hülya; Fıratlı, Erhan

    2014-01-01

    We developed a new product called titanium-prepared platelet-rich fibrin (T-PRF). The T-PRF method is based on the hypothesis that titanium may be more effective in activating platelets than the silica activators used with glass tubes in Chouckroun's leukocyte- and platelet-rich fibrin (L-PRF) method. In this study, we aimed to define the structural characteristics of T-PRF and compare it with L-PRF. Blood samples were collected from 10 healthy male volunteers. The blood samples were drawn using a syringe. Nine milliliters was transferred to a dry glass tube, and 9 mL was transferred to a titanium tube. Half of each clot (i.e., the blood that was clotted using T-PRF or L-PRF) was processed with a scanning electron microscope (SEM). The other half of each clot was processed for fluorescence microscopy analysis and light microscopy analysis. The T-PRF samples seemed to have a highly organized network with continuous integrity compared to the other L-PRF samples. Histomorphometric analysis showed that T-PRF fibrin network covers larger area than L-PRF fibrin network; also fibrin seemed thicker in the T-PRF samples. This is the first human study to define T-PRF as an autogenous leukocyte- and platelet-rich fibrin product. The platelet activation by titanium seems to offer some high characteristics to T-PRF.

  11. Flavanols and Platelet Reactivity

    Directory of Open Access Journals (Sweden)

    Debra A. Pearson

    2005-01-01

    Full Text Available Platelet activity and platelet-endothelial cell interactions are important in the acute development of thrombosis, as well as in the pathogenesis of cardiovascular disease. An increasing number of foods have been reported to have platelet-inhibitory actions, and research with a number of flavanol-rich foods, including, grape juice, cocoa and chocolate, suggests that these foods may provide some protection against thrombosis. In the present report, we review a series of in vivo studies on the effects of flavanol-rich cocoa and chocolate on platelet activation and platelet-dependent primary hemostasis. Consumption of flavanol-rich cocoa inhibited several measures of platelet activity including, epinephrine- and ADP-induced glycoprotein (GP IIb/IIIa and P-Selectin expression, platelet microparticle formation, and epinephrine-collagen and ADP-collagen induced primary hemostasis. The epinephrine-induced inhibitory effects on GP IIb/IIIa and primary hemostasis were similar to, though less robust than those associated with the use of low dose (81 mg aspirin. These data, coupled with information from other studies, support the concept that flavanols present in cocoa and chocolate can modulate platelet function through a multitude of pathways.

  12. Alloimmune refractoriness to platelet transfusions.

    Science.gov (United States)

    Sandler, S G

    1997-11-01

    Patients who are transfused on multiple occasions with red cells or platelets may develop platelet-reactive alloantibodies and experience decreased clinical responsiveness to platelet transfusion. This situation, conventionally described as "refractoriness to platelet transfusions," is defined by an unsatisfactory low post-transfusion platelet count increment. If antibodies to HLAs are detected, improved clinical outcomes may result from transfusions of HLA-matched or donor-recipient cross-matched platelets. Because refractoriness is an expected, frequently occurring phenomenon, prevention of HLA alloimmunization is an important management strategy. Prevention strategies include efforts to decrease the number of transfusions, filtration of cellular components to reduce the number of HLA-bearing leukocytes, or pretransfusion ultraviolet B irradiation of cellular components to decrease their immunogenicity. Other investigational approaches include reducing the expression of HLAs on transfused platelets, inducing a transient reticuloendothelial system blockade by infusions of specialized immunoglobulin products, or transfusing semisynthetic platelet substitutes (thromboerythrocytes, thrombospheres) or modified platelets (infusible platelet membranes, lyophilized platelets).

  13. Role of platelets in the pathogenesis of antiphospholipid syndrome

    Directory of Open Access Journals (Sweden)

    NK Singh

    2013-07-01

    Full Text Available AimTo delineate the role of platelets in thrombotic process in APS patients.BackgroundPathogenesis of APS is an ongoing area of research and studying the role of platelets will be helpful in developing newer diagnostic and therapeutic strategies.Materials and methodsForty patients with APS, diagnosed as per modified 2006 Sapporo’s Criteria and who were not on aspirin or any other antiplatelet drug, were included. The same number of age- and sex-matched healthy controls was also recruited for comparison. The following platelet function studies were performed using the blood samples collected from APS patients as well as healthy controls: platelet aggregation studies, platelet secretion of dense granules (a. total degranulation b. platelet secretion of granules in relation to time c. visualization of platelet degranulation, clot retraction studies, and western blot studies on clot retracted samples for demonstration of activated proteomes.ResultsA significant increase (P < 0.001 in the platelet aggregation in APS patients as compared to healthy controls was noted. The subjects also showed a significant increase (P < 0.05 in the platelet granule release as well as more degranulation (P < 0.001 in relation to time at stored condition, which were well-visualized under phase-contrast microscope. Sixty-five percent of APS patients showed lesser as well as delayed clot retraction as compared to healthy controls, signifying that the platelet clots are less retractile in APS patients.ConclusionThe study clearly demonstrates the hyperactivity of platelets in APS patients in each step of their activation as compared to the controls. This indicates the major role played by platelets in APS pathogenesis.

  14. Cisplatin triggers platelet activation.

    Science.gov (United States)

    Togna, G I; Togna, A R; Franconi, M; Caprino, L

    2000-09-01

    Clinical observations suggest that anticancer drugs could contribute to the thrombotic complications of malignancy in treated patients. Thrombotic microangiopathy, myocardial infarction, and cerebrovascular thrombotic events have been reported for cisplatin, a drug widely used in the treatment of many solid tumours. The aim of this study is to explore in vitro cisplatin effect on human platelet reactivity in order to define the potentially active role of platelets in the pathogenesis of cisplatin-induced thrombotic complications. Our results demonstrate that cisplatin increases human platelet reactivity (onset of platelet aggregation wave and thromboxane production) to non-aggregating concentrations of the agonists involving arachidonic acid metabolism. Direct or indirect activation of platelet phospholipase A(2) appears to be implicated. This finding contributes to a better understanding of the pathogenesis of thrombotic complications occurring during cisplatin-based chemotherapy.

  15. The quantitative and qualitative responses of platelets in pediatric patients undergoing cardiopulmonary bypass surgery.

    Science.gov (United States)

    Ignjatovic, Vera; Than, Jenny; Summerhayes, Robyn; Newall, Fiona; Horton, Steve; Cochrane, Andrew; Monagle, Paul

    2012-01-01

    This prospective, single-center study aimed to evaluate the platelet response during cardiopulmonary bypass (CPB) surgery in a large cohort of children up to 6 years of age. Blood samples were drawn at four time points: after induction of anesthesia, after initiation of the CPB, before protamine, and immediately after chest closure. The study recruited 60 children requiring CPB for surgical repair of congenital heart defects. The platelet count decreased throughout CPB surgery, but during the same period, platelet activity increased. The more pronounced decrease in platelet count observed in children younger than 1 year compared with that of children 1 to 6 years of age was not associated with an age-specific change in platelet activity. The overall increase in platelet function observed in this study could provide a mechanism that compensates for the decrease in platelet count. This study provides a new foundation for future studies investigating requirements of platelet supplementation in the setting of pediatric CPB surgery.

  16. Evaluation of electrical aggregometry: comparison with optical aggregometry, secretion of ATP, and accumulation of radiolabeled platelets

    Energy Technology Data Exchange (ETDEWEB)

    Ingerman-Wojenski, C.; Smith, J.B.; Silver, M.J.

    1983-01-01

    Platelet aggregation has been most commonly studied in vitro by measuring increases in light transmission as platelets aggregate in PRP (platelet-rich plasma). Recently, an electrical impedance method for measuring platelet aggregation has been introduced. This method can be used with either PRP or whole blood and measures an increase in impedance across electrodes placed in the blood samples as platelets accumulate on them. Results obtained by the two methods were compared using ADP and collagen as aggregating agents, and also have measured the secretion of platelet ATP simultaneously. Although the aggregometry results were similar, recordings obtained by the electrical method did not distinguish two waves of platelet aggregation or correlate with secretion as well as recordings obtained by the optical method. When PGI/sub 2/ (prostacyclin) or PGE/sub 1/ (prostaglandin E/sub 1/) was added to the PRP, both the rate and extent of the increase in light transmittance were inhibited, but the main effect on the increase in impedance was a decrease in its rate and not in its extent. Increases in impedance and secretion of ATP were also measured in whole blood after the platelets had been labeled with a /sup 125/I-containing antibody specific for platelet surface glycoproteins. It appeared that the increases in impedance lagged several minutes behind the formation of platelet aggregates and the secretion of platelet ATP.

  17. 21 CFR 864.9575 - Environmental chamber for storage of platelet concentrate.

    Science.gov (United States)

    2010-04-01

    ... to hold platelet-rich plasma within a preselected temperature range. (b) Classification. Class II... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Environmental chamber for storage of platelet... Establishments That Manufacture Blood and Blood Products § 864.9575 Environmental chamber for storage of...

  18. Erythrocyte and platelet proteomics in hematological disorders.

    Science.gov (United States)

    Chakrabarti, Abhijit; Halder, Suchismita; Karmakar, Shilpita

    2016-04-01

    Erythrocytes undergo ineffective erythropoesis, hemolysis, and premature eryptosis in sickle cell disease and thalassemia. Abnormal hemoglobin variants associated with hemoglobinopathy lead to vesiculation, membrane instability, and loss of membrane asymmetry with exposal of phosphatidylserine. This potentiates thrombin generation resulting in activation of the coagulation cascade responsible for subclinical phenotypes. Platelet activation also results in the release of microparticles, which express and transfer functional receptors from platelet membrane, playing key roles in vascular reactivity and activation of intracellular signaling pathways. Over the last decade, proteomics had proven to be an important field of research in studies of blood and blood diseases. Blood cells and its fluidic components have been proven to be easy systems for studying differential expressions of proteins in hematological diseases encompassing hemoglobinopathies, different types of anemias, myeloproliferative disorders, and coagulopathies. Proteomic studies of erythrocytes and platelets reported from several groups have highlighted various factors that intersect the signaling networks in these anucleate systems. In this review, we have elaborated on the current scenario of anucleate blood cell proteomes in normal and diseased individuals and the cross-talk between the two major constituent cell types of circulating blood.

  19. Mice lacking the SLAM family member CD84 display unaltered platelet function in hemostasis and thrombosis.

    Directory of Open Access Journals (Sweden)

    Sebastian Hofmann

    Full Text Available BACKGROUND: Platelets are anuclear cell fragments derived from bone marrow megakaryocytes that safeguard vascular integrity by forming thrombi at sites of vascular injury. Although the early events of thrombus formation--platelet adhesion and aggregation--have been intensively studied, less is known about the mechanisms and receptors that stabilize platelet-platelet interactions once a thrombus has formed. One receptor that has been implicated in this process is the signaling lymphocyte activation molecule (SLAM family member CD84, which can undergo homophilic interactions and becomes phosphorylated upon platelet aggregation. OBJECTIVE: The role of CD84 in platelet physiology and thrombus formation was investigated in CD84-deficient mice. METHODS AND RESULTS: We generated CD84-deficient mice and analyzed their platelets in vitro and in vivo. Cd84(-/- platelets exhibited normal activation and aggregation responses to classical platelet agonists. Furthermore, CD84 deficiency did not affect integrin-mediated clot retraction and spreading of activated platelets on fibrinogen. Notably, also the formation of stable three-dimensional thrombi on collagen-coated surfaces under flow ex vivo was unaltered in the blood of Cd84(-/- mice. In vivo, Cd84(-/- mice exhibited unaltered hemostatic function and arterial thrombus formation. CONCLUSION: These results show that CD84 is dispensable for thrombus formation and stabilization, indicating that its deficiency may be functionally compensated by other receptors or that it may be important for platelet functions different from platelet-platelet interactions.

  20. Platelet-collagen adhesion enhances platelet aggregation induced by binding of VWF to platelets

    Energy Technology Data Exchange (ETDEWEB)

    Laduca, F.M.; Bell, W.R.; Bettigole, R.E. (Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA) State Univ. of New York, Buffalo (USA))

    1987-11-01

    Ristocetin-induced platelet aggregation (RIPA) was evaluated in the presence of platelet-collagen adhesion. RIPA of normal donor platelet-rich plasma (PRP) demonstrated a primary wave of aggregation mediated by the binding of von Willebrand factor (VWF) to platelets and a secondary aggregation wave, due to a platelet-release reaction, initiated by VWF-platelet binding and inhibitable by acetylsalicylic acid (ASA). An enhanced RIPA was observed in PRP samples to which collagen had been previously added. These subthreshold concentrations of collagen, which by themselves were insufficient to induce aggregation, caused measurable platelet-collagen adhesion. Subthreshold collagen did not cause microplatelet aggregation, platelet release of ({sup 3}H)serotonin, or alter the dose-responsive binding of {sup 125}I-labeled VWF to platelets, which occurred with increasing ristocetin concentrations. However, ASA inhibition of the platelet release reaction prevented collagen-enhanced RIPA. These results demonstrate that platelet-collagen adhesion altered the platelet-release reaction induced by the binding of VWF to platelets causing a platelet-release reaction at a level of VWF-platelet binding not normally initiating a secondary aggregation. These findings suggest that platelet-collagen adhesion enhances platelet function mediated by VWF.

  1. Megakaryocytes and platelets express nicotinic acetylcholine receptors but nicotine does not affect megakaryopoiesis or platelet function.

    Science.gov (United States)

    Schedel, Angelika; Kaiser, Kerstin; Uhlig, Stefanie; Lorenz, Florian; Sarin, Anip; Starigk, Julian; Hassmann, Dennis; Bieback, Karen; Bugert, Peter

    2016-01-01

    In our previous investigations we have shown that platelets and their precursors express nicotinic α7 acetylcholine receptors (nAChRα7) that are involved in platelet function and in vitro differentiation of the megakaryoblastic cell line MEG-01. In this study, we were interested in the expression analysis of additional nAChR and the effects of nicotine in an ex vivo model using megakaryocytic cells differentiated from cord blood derived CD34(+) cells (CBMK) and an in vivo model using blood samples from smokers. CBMK were differentiated with thrombopoietin (TPO) for up to 17 days. Quantitative real-time PCR (QRT-PCR), Western blot analysis and flow cytometry were used to investigate nAChR expression (nAChRα7, nAChRα4, nAChRβ2) and nicotine effects. In blood samples of 15 nonsmokers and 16 smokers platelet parameters (count, mean platelet volume--MPV and platelet distribution width--PDW) were determined as indicators for changes of in vivo megakaryopoiesis. Platelet function was determined by the use of whole blood aggregometry and flow cytometry. The functional role of nAChR was evaluated using specific antagonists in aggregometry. CHRNA7, CHRNA4 and CHRNB2 gene transcripts and the corresponding proteins could be identified in CBMK during all stages of differentiation. Platelets contain nAChRα7 and nAChRβ2 but not nAChRα4. Nicotine had no effect on TPO-induced differentiation of CBMK. There was no significant difference in all platelet parameters of the smokers compared to the nonsmokers. In line with this, cholinergic gene transcripts as well as the encoded proteins were equally expressed in both the study groups. Despite our observation of nAChR expression in megakaryopoiesis and platelets, we were not able to detect effects of nicotine in our ex vivo and in vivo models. Thus, the functional role of the nAChR in these cells remains open.

  2. Effect of Composite Salvia Injection on Platelet Parameters in Children with Anaphylactoid Purpura

    Institute of Scientific and Technical Information of China (English)

    谢雪兰; 寇素茹; 许月红; 李朝英

    2009-01-01

    Objective:To explore the effect of composite salvia injection(CSI) on platelet parameters in children with anaphylactoid purpura(AP) and its clinical significance.Methods:One hundred and fifty children with AP were assigned to two groups,80 in Group A and 70 in Group B.They were treated,respectively,with conventional therapy only or conventional therapy combined with CSI.Their platelet parameters,including blood platelet count(BPC),mean platelet volume(MPV),platelet distribution width(PDW) and plateletcr...

  3. A new type of pseudothrombocytopenia: EDTA-mediated agglutination of platelets bearing Fab fragments of a chimaeric antibody.

    Science.gov (United States)

    Christopoulos, C G; Machin, S J

    1994-07-01

    In vitro agglutination of platelets leading to low automated platelet counts was observed in EDTA-anticoagulated blood from human volunteers receiving infusions of Fab fragments of a chimaeric monoclonal antibody to platelet glycoprotein IIb-IIIa. This pseudothrombocytopenia depended on the presence of chimaeric Fab on the platelet surface and was not seen when sodium citrate was used as anticoagulent. Preliminary evidence suggests that this phenomenon might be mediated by immunoglobulin G reactive with the human component of the chimaeric Fab. It is important to exclude pseudothrombocytopenia when low automated platelet counts are reported in association with the administration of chimaeric anti-platelet antibodies.

  4. Pressure-aided transfusion of platelets: does it affect the platelets?

    DEFF Research Database (Denmark)

    Fischer-Nielsen, Anne; Stissing, Trine; Maansson, Charlotte;

    2010-01-01

    In massively bleeding patients, pressure infusers are used for transfusion of red blood cells and plasma but not for platelets (PLTs) due to an assumed negative effect on the PLTs. This study examined whether pressure-aided in vitro transfusion affected the number, activation state, and/or function...

  5. Transfused stored platelets have the same haemostatic function as circulating native platelets

    NARCIS (Netherlands)

    Roeloffzen, W. W. H.; Kluin-Nelemans, H. C.; Veeger, N. J. G. M.; de Wolf, J. Th. M.

    2010-01-01

    Background and objectives As thrombelastography (R) (TEG) measures haemostasis in whole blood, we used this instrument to study whether transfused platelets (PLTs) have the same haemostatic function compared to native circulating PLTs. Further, we studied the effect of storage time on the haemostati

  6. Defining Platelet Function During Polytrauma

    Science.gov (United States)

    2013-02-01

    using calibrated automated thrombography ( CAT ). 3. Platelet-induced clot contraction and using viscoelastic measures such as TEG with Platelet Mapping...using calibrated automated thrombography ( CAT ) in platelet-rich plasma. 3. Platelet-induced clot contraction and effect on clot structure by platelet...if injury with stable vital signs on initial evaluation.  Pregnancy (confirmed with urine pregnancy testing)  Documented do not resuscitate order

  7. Migration distance-based platelet function analysis in a microfluidic system.

    Science.gov (United States)

    Song, Suk-Heung; Lim, Chae-Seung; Shin, Sehyun

    2013-01-01

    Aggregation and adhesion of platelets to the vascular wall are shear-dependent processes that play critical roles in hemostasis and thrombosis at vascular injury sites. In this study, we designed a simple and rapid assay of platelet aggregation and adhesion in a microfluidic system. A shearing mechanism using a rotating stirrer provided adjustable shear rate and shearing time and induced platelet activation. When sheared blood was driven through the microchannel under vacuum pressure, shear-activated platelets adhered to a collagen-coated surface, causing blood flow to significantly slow and eventually stop. To measure platelet adhesion and aggregation, the migration distance (MD) of blood through the microchannel was monitored. As the microstirrer speed increased, MD initially decreased exponentially but then increased beyond a critical rpm. For platelet-excluded blood samples, there were no changes in MD with increasing stirrer speed. These findings imply that the stirrer provided sufficiently high shear to activate platelets and that blood MD is a potentially valuable index for measuring the shear-dependence of platelet activation. Our microfluidic system is quick and simple, while providing a precise assay to measure the effects of shear on platelet aggregation and adhesion.

  8. Increased platelet expression of FcGammaRIIa and its potential impact on platelet reactivity in patients with end stage renal disease

    Directory of Open Access Journals (Sweden)

    Sobel Burton E

    2007-06-01

    Full Text Available Abstract Background Increased platelet reactivity has been implicated in cardiovascular disease – the major cause of death in patients with end stage renal disease (ESRD. FcGammaRIIA is a component of glycoprotein VI and Ib-IX-V that mediate activation of platelets by collagen and von Willebrand factor. To determine whether expression of FcGammaRIIA impacts platelet reactivity we quantified its expression and platelet reactivity in 33 patients with ESRD who were undergoing hemodialysis. Methods Blood samples were obtained from patients immediately before hemodialysis and before administration of heparin. Platelet expression of FcGammaRIIA and the activation of platelets in response to low concentrations of convulxin (1 ng/ml, selected to mimic effects of collagen, thrombin (1 nM, adenosine diphosphate (ADP, 0.2 uM, or platelet activating factor (PAF, 1 nM were determined with the use of flow cytometry in samples of whole blood anticoagulated with corn trypsin inhibitor (a specific inhibitor of Factor XIIa. Results Patients were stratified with respect to the median expression of FcGammaRIIA. Patients with high platelet expression of FcGammaRIIA exhibited 3-fold greater platelet reactivity compared with that in those with low expression in response to convulxin (p Conclusion Increased platelet reactivity in response to low concentrations of diverse agonists is associated with high expression of FcGammaRIIA and may contribute to an increased risk of thrombosis in patients with ESRD.

  9. Effect of a Korean traditional formulation, Hwaotang, on superoxide generation in human neutrophils, platelet aggregation in human blood, and nitric oxide, prostaglandin E2 production and paw oedema induced by carrageenan in mice.

    Science.gov (United States)

    Park, Won-Hwan; Park, Soo-Young; Kim, Hyung-Min; Kim, Cheorl-Ho

    2004-02-01

    Hwaotang, a traditional Korean medicinal formulation, is a dried decoctum of a mixture of 7 herbal medicines, consisting of Angelica gigantis Radix, Rehmanniae radix, Paeoniae radix, Ciniamomi cortex, Cnidii rhizoma, Persicae semen and Carthami flos. We have investigated that Hwaotang water extract (HOT) has various effects on stimulus-induced superoxide generation in human neutrophils. The effects of HOT on superoxide generation in human neutrophils were investigated. HOT significantly inhibited N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced superoxide generation in a concentration-dependent manner, but not that induced by arachidonic acid (AA). On the other hand, HOT enhanced superoxide generation induced by phorbol 12-myristate 13-acetate (PMA) in a concentration-dependent manner. The superoxide generation induced by PMA with HOT was suppressed by staurosporine, an inhibitor of protein kinase C, but was not suppressed by genistein, an inhibitor of protein tyrosine kinase. Tyrosyl phosphorylation of a 58 kDa protein, which was increased by fMLP, was inhibited by HOT. HOT also inhibited the generation of a 47 kDa protein and platelet aggregation in human blood. The results suggest that protein tyrosine kinase participates in fMLP-mediated superoxide generation by HOT-treated human neutrophils. HOT inhibited neutrophil functions, including degranulation, superoxide generation, and leukotriene B4 production, without any effect on 5-lipoxygenase activity. HOT reduced nitric oxide (NO) and prostaglandin E2 production in mouse peritoneal macrophages stimulated with lipopolysaccharide, whereas no influence on the activity of iNOS, COX-2 or COX-1 was observed. HOT significantly reduced mouse paw oedema induced by carrageenan. Western blot analysis showed that HOT reduced the expression of iNOS and COX-2. The results indicate that HOT exerts anti-inflammatory effects related to the inhibition of neutrophil functions and of NO and prostaglandin E2 production, which

  10. Platelet adhesion to polyurethane urea under pulsatile flow conditions.

    Science.gov (United States)

    Navitsky, Michael A; Taylor, Joshua O; Smith, Alexander B; Slattery, Margaret J; Deutsch, Steven; Siedlecki, Christopher A; Manning, Keefe B

    2014-12-01

    Platelet adhesion to a polyurethane urea surface is a precursor to thrombus formation within blood-contacting cardiovascular devices, and platelets have been found to adhere strongly to polyurethane surfaces below a shear rate of approximately 500 s(-1). The aim of the current work is to determine the properties of platelet adhesion to the polyurethane urea surface as a function of time-varying shear exposure. A rotating disk system was used to study the influence of steady and pulsatile flow conditions (e.g., cardiac inflow and sawtooth waveforms) for platelet adhesion to the biomaterial surface. All experiments were conducted with the same root mean square angular rotation velocity (29.63 rad/s) and waveform period. The disk was rotated in platelet-rich bovine plasma for 2 h, with adhesion quantified by confocal microscopy measurements of immunofluorescently labeled bovine platelets. Platelet adhesion under pulsating flow was found to decay exponentially with increasing shear rate. Adhesion levels were found to depend upon peak platelet flux and shear rate, regardless of rotational waveform. In combination with flow measurements, these results may be useful for predicting regions susceptible to thrombus formation within ventricular assist devices.

  11. Sources of variability in platelet accumulation on type 1 fibrillar collagen in microfluidic flow assays.

    Directory of Open Access Journals (Sweden)

    Keith B Neeves

    Full Text Available Microfluidic flow assays (MFA that measure shear dependent platelet function have potential clinical applications in the diagnosis and treatment of bleeding and thrombotic disorders. As a step towards clinical application, the objective of this study was to measure how phenotypic and genetic factors, as well as experimental conditions, affect the variability of platelet accumulation on type 1 collagen within a MFA. Whole blood was perfused over type 1 fibrillar collagen at wall shear rates of 150, 300, 750 and 1500 s⁻¹ through four independent channels with a height of 50 µm and a width of 500 µm. The accumulation of platelets was characterized by the lag time to 1% platelet surface coverage (Lag(T, the rate of platelet accumulation (V(PLT, and platelet surface coverage (SC. A cohort of normal donors was tested and the results were correlated to plasma von Willebrand factor (VWF levels, platelet count, hematocrit, sex, and collagen receptors genotypes. VWF levels were the strongest determinant of platelet accumulation. VWF levels were positively correlated to V(PLT and SC at all wall shear rates. A longer Lag(T for platelet accumulation at arterial shear rates compared to venous shear rates was attributed to the time required for plasma proteins to adsorb to collagen. There was no association between platelet accumulation and hematocrit or platelet count. Individuals with the AG genotype of the GP6 gene had lower platelet accumulation than individuals with the AA genotype at 150 s⁻¹ and 300 s⁻¹. Recalcified blood collected into sodium citrate and corn trypsin inhibitor (CTI resulted in diminished platelet accumulation compared to CTI alone, suggesting that citrate irreversibly diminishes platelet function. This study the largest association study of MFA in healthy donors (n = 104 and will likely set up the basis for the determination of the normal range of platelet responses in this type of assay.

  12. The Impact of Platelet Transfusion in Massively Transfused Trauma Patients

    Science.gov (United States)

    2010-11-01

    packed red blood cells [PRBC] within 24 hours of admission). Mortality was evaluated according to 4 apheresis platelet (aPLT):PRBC ratios: Low ratio (1...a massive transfusion, as the apheresis platelet-to-red cell ratio increased, a stepwise improvement in survival was seen. Prospective evaluation of...6.6 9.9 5.5 9.6 0.001 *FFP:PRBC ratio (%) (units FFP/units PRBC) 100. aPLT, apheresis platelets; FFP, fresh frozen plasma; PRBC, packed red

  13. Human platelet glycoprotein Ia. One component is only expressed on the surface of activated platelets and may be a granule constituent

    Energy Technology Data Exchange (ETDEWEB)

    Bienz, D.; Clemetson, K.J.

    1989-01-05

    Glycoprotein Ia (GP Ia) is a relatively minor component of human blood platelets thought to be a receptor involved in collagen-induced platelet activation. However, some difficulties exist with the definition of this glycoprotein. The expression of GP Ia on resting (prostacyclin analogue-treated) and thrombin-activated platelets was compared by surface labeling with /sup 125/I-lactoperoxidase. Intact platelets or platelets solubilized in sodium dodecyl sulfate were labeled with periodate/(/sup 3/H)NaBH/sub 4/. Analysis on two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels showed that GP Ia is very poorly labeled in resting platelets. After activation a new spot (GP Ia*) appears with the same relative molecular mass as GP Ia under reducing conditions. GP Ia and Ia* can be clearly separated by two-dimensional nonreduced/reduced gel electrophoresis. Therefore, two glycoproteins which have been termed GP Ia exist in platelets with similar molecular weight and pI under reducing conditions. One of these (GP Ia*) is only surface-labeled when platelets are activated, indicating that it is only exposed on the surface of activated platelets. Supernatant from activated platelets contains this glycoprotein as well as other granule components. This glycoprotein is missing in platelets from two patients with collagen-response defects.

  14. Evaluation of a BED-SIDE Platelet Function Assay : Performance and Clinical Utility.

    Directory of Open Access Journals (Sweden)

    Lau Wei

    2002-01-01

    Full Text Available Platelets have a pivotal role in the initial defense against insult to the vasculature and are also recognized of critical importance in the acute care settings of percutaneous coronary intervention and cardiopulmonary bypass. In these environments both platelet count and function may be markedly compromised. Unfortunately, current assays to evaluate the parameters of platelet count and function are of limited utility for bed-side testing. Moreover, it is suggested that there may be significant inter patient variation in response to antiplatelet therapy that may be exacerbated by other agents (e.g. heparin that are routinely administered during cardiac intervention. Here we describe a practical, rapid and user-friendly whole blood platelet function assay that has been developed for use in bed-side settings. Platelet agonists were formulated with an anticoagulant and lyophilized in blood collection tubes standardised to receive a l mL fresh whole blood sample. In the presence of an agonist, platelets are activated and interact (aggregate. Using traditional cell counting principles, non-aggregated platelets are counted whereas aggregated platelets are not. The percentage (% of functional platelets in reference to a baseline tube may then be determined. Results are available within four minutes. Platelet aggregation in whole blood demonstrated good correlation with turbidometric aggregometry for both ADP (r=0.91 and collagen (r=0.88. Moreover, in clinical settings where antiplatelet agents were administered, this rapid, bed-side, platelet function assay demonstrated utility in monitoring patient response to these therapies. This novel bed-side assay of platelet function is extremely suitable for the clinical environment with a rapid turn-around time. In addition, it provides a full haematology profile, including platelet count, and should permit enhancement of transfusion and interventional decisions.

  15. Refractory platelet transfusion in a patient with CD36 deficiency due to pseudothrombocytopenia.

    Science.gov (United States)

    Yin, Xiao-Lin; Shen, Wei-Dong; Chen, Yong-Sheng; Zhou, Yan; Zhang, Xin-Huan

    2011-01-01

    Type I CD36 deficiency is defined by the absence of CD36 on both platelets and monocytes. Pseudothrombocytopenia (PTCP) is characterized by a false reduction in the number of platelets in ethylenediaminetetraacetic acid (EDTA)-anticoagulated blood. Here we report a rare case of concomitant CD36 deficiency and PTCP. The patient was a 7-year-old boy who suffered comminuted fractures of the left humeral condyle. In the pre-operative examination, he was found to have thrombopenia and assumed to have idiopathic thrombocytopenic purpura. After immunotherapy and platelet transfusion, the platelet count remained low, suggesting that the patient was refractory to platelet transfusion. Serum was collected for the detection of platelet antibodies, and antibodies against CD36 were found. Flow cytometry verified the absence of CD36 on both the platelets and monocytes of this patient. However, the platelet count was normal when capillary blood smears were analysed; in addition, platelet coagulation was noted under the microscope when EDTA-anticoagulated peripheral blood was used. The patient underwent surgery without platelet transfusion and recovered uneventfully.

  16. Platelet-rich fibrin (PRF): a second-generation platelet concentrate. Part III: leucocyte activation: a new feature for platelet concentrates?

    Science.gov (United States)

    Dohan, David M; Choukroun, Joseph; Diss, Antoine; Dohan, Steve L; Dohan, Anthony J J; Mouhyi, Jaafar; Gogly, Bruno

    2006-03-01

    Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. In this third article, we investigate the immune features of this biomaterial. During PRF processing, leucocytes could also secrete cytokines in reaction to the hemostatic and inflammatory phenomena artificially induced in the centrifuged tube. We therefore undertook to quantify 5 significant cell mediators within platelet poor plasma supernatant and PRF clot exudate serum: 3 proinflammatory cytokines (IL-1beta, IL-6, and TNF-alpha), an antiinflammatory cytokine (IL-4), and a key growth promoter of angiogenesis (VEGF). Our data are correlated with that obtained in plasma (nonactivated blood) and in sera (activated blood). These initial analyses revealed that PRF could be an immune regulation node with inflammation retrocontrol abilities. This concept could explain the reduction of postoperative infections when PRF is used as surgical additive.

  17. PLATELET RICH PLASMA (PRP) APPLICATION IN TOTAL KNEE ARTHROPLASTY (TKA)

    OpenAIRE

    2015-01-01

    PURPOSE: To find out the PRP application effects in TKA on pain syndrome, wound healing, postoperative blood loss, range of motion and the knee circumference (centimetry). MATERIAL AND METHOD: The preparation of the platelet-rich plasma is based on our treatment algorithm. 20 patients have been subject to TKA within the period from October 2012 to November 2014 and underwent TKA, as platelet rich plasma was used intraoperatively. The average patient age is 72,3; 9 male and 11 female patien...

  18. Platelets in the neonatal period: developmental differences in platelet production, function, and hemostasis and the potential impact of therapies.

    Science.gov (United States)

    Sola-Visner, Martha

    2012-01-01

    Thrombocytopenia is a common problem among sick neonates admitted to the neonatal intensive care unit. Frequently, platelet transfusions are given to thrombocytopenic infants in an attempt to decrease the incidence or severity of hemorrhage, which is often intracranial. Whereas there is very limited evidence to guide platelet transfusion practices in this population, preterm infants in the first week of life (the highest risk period for bleeding) are nearly universally transfused at higher platelet counts than older infants or children. To a large extent, this practice has been influenced by the observation that neonatal platelets are hyporeactive in response to multiple agonists in vitro, although full-term infants exhibit normal to increased primary hemostasis. This apparently paradoxical finding is due to factors in the neonatal blood that enhance the platelet-vessel wall interaction and counteract the platelet hyporeactivity. Relatively few studies have evaluated the platelet function and primary hemostasis of preterm infants, the subset of neonates at highest risk of bleeding and those most frequently transfused. Current understanding of platelet production and function in preterm and full-term neonates, how these factors affect their response to thrombocytopenia and their primary hemostasis, and the implications of these developmental differences to transfusion medicine are reviewed herein.

  19. Platelet preservation: agitation and containers.

    Science.gov (United States)

    van der Meer, Pieter F; de Korte, Dirk

    2011-06-01

    For platelets to maintain their in vitro quality and in vivo effectiveness, they need to be stored at room temperature with gentle agitation in gas-permeable containers. The mode of agitation affects the quality of the platelets, and a gentle method of agitation, either a circular or a flat bed movement, provides the best results. Tumblers or elliptical agitators induce platelet activation and subsequent damage. As long as the platelets remain in suspension, the agitation speed is not important. Agitation of the platelet concentrates ensures that the platelets are continuously oxygenated, that sufficient oxygen can enter the storage container and that excess carbon dioxide can be expelled. During transportation of platelet concentrates, nowadays over long distances where they are held without controlled agitation, platelets may tolerate a certain period without agitation. However, evidence is accumulating that during the time without agitation, local hypoxia surrounding the platelets may induce irreversible harm to the platelets. Over the decades, more gas-permeable plastics have been used to manufacture platelet containers. The use of different plastics and their influence on the platelet quality both in vitro and in vivo is discussed. The improved gas-permeability has allowed the extension of platelet storage from 3 days in the early 1980s, to currently at least 7 days. In the light of new developments, particularly the introduction of pathogen reduction techniques, the use of platelet additive solutions and the availability of improved automated separators, further (renewed) research in this area is warranted.

  20. Platelets Roll on Stimulated Endothelium in vivo: An Interaction Mediated by Endothelial P-Selectin

    Science.gov (United States)

    Frenette, Paul S.; Johnson, Robert C.; Hynes, Richard O.; Wagner, Denisa D.

    1995-08-01

    P-selectin, found in storage granules of platelets and endothelial cells, can be rapidly expressed upon stimulation. Mice lacking this membrane receptor exhibit a severe impairment of leukocyte rolling. We observed that, in addition to leukocytes, platelets were rolling in mesenteric venules of wild-type mice. To investigate the role of P-selectin in this process, resting or activated platelets from wild-type or P-selectin-deficient mice were fluorescently labeled and transfused into recipients of either genotype. Platelet-endothelial interactions were monitored by intravital microscopy. We observed rolling of either wild-type or P-selectin-deficient resting platelets on wild-type endothelium. Endothelial stimulation with the calcium ionophore A23187 increased the number of platelets rolling 4-fold. Activated P-selectin-deficient platelets behaved similarly, whereas activated wild-type platelets bound to leukocytes and were seen rolling together. Platelets of either genotype, resting or activated, interacted minimally with mutant endothelium even after A23187 treatment. The velocity of platelet rolling was 6- to 9-fold greater than that of leukocytes. Our results demonstrate that (i) platelets roll on endothelium in vivo, (ii) this interaction requires endothelial but not platelet P-selectin, and (iii) platelet rolling appears to be independent of platelet activation, indicating constitutive expression of a P-selectin ligand(s) on platelets. We have therefore observed an interesting parallel between platelets and leukocytes in that both of these blood cell types roll on stimulated vessel wall and that this process is dependent on the expression of endothelial P-selectin.

  1. Dogs with hearth diseases causing turbulent high-velocity blood flow have changes in patelet function and von Willebrand factor multimer distribution

    DEFF Research Database (Denmark)

    Tarnow, Inge; Kristensen, Annemarie Thuri; Olsen, Lisbeth Høier

    2005-01-01

    and echocardiography were performed in all dogs. PFA100 closure times (the ability of platelets to occlude a hole in a membrane at high shear rates), platelet activation markers (plasma thromboxane B2 concentration, platelet surface P-selectin expression), platelet aggregation (in whole blood and platelet-rich plasma...

  2. Blood Donation Population Human Platelet Antigen of 1~5 System Gene Polymorphism Distribution Characteristics%献血人群人类血小板抗原1~5系统基因多态性分布特点

    Institute of Scientific and Technical Information of China (English)

    徐向华

    2015-01-01

    目的:探讨献血人群人类血小板抗原1~5系统基因多态性分布特点。方法采用聚合酶链-序列特异性引物技术(PCR-SSP)对200例无血缘关系的健康献血者进行HPA-1-5系统基因分型,分别计算献血人群的基因型及基因频率,分析其基因的多态性分布特点。结果该研究中献血人群HPA-1a、2a、3a、4a、5a基因频率分别为:0.942、0.741、0.926、0.945、0.773,HPA-1b、2b、3b、4b、5b基因频率分别为:0.058、0.286、0.084、0.045、0.227,各系统均呈多态性分布, ab杂合子依次为64和30例,-2bb4例;HPA-3和-15高度杂合,aa基因型依次为112和80例,很多献血人群属于bb基因型。结论该地区献血人群HPA-1-5系统基因均呈多态性分布,以HPA-3、-2和-5的a与b基因杂合率较高。%Objective To investigate the blood donation population human platelet antigen of 1 ~ 5 system gene polymorphism distribution characteristics.Methods Polymerase chain - sequence specific primers (PCR SSP) technology to the health of 200 cases of unrelated donors to HPA genotyping-1-5 system, gene frequency and genotype of the blood donation population are calculated respectively, analyze its gene polymorphism distribution characteristics.Results The study of blood donation population HPA - 1 a、2 a、3 a、4 a、5 a gene frequency are: 0.942、0.741、0.926、 0.741、0.926,HPA - 1 b、2 b、3 b、4 b、5 b gene frequencies are: 0.058、 0.286、0.084、0.286、0.084, are distributed in each system are polymorphism, ab heterozygous for 64 and 30 cases, in turn - 2 bb4 cases; HPA - 3 and 15 highly heterozygous, aa genotype was followed by 242 and 210, many line but people belong to the bb genotype. Conclusion This area crowd HPA - 1-5 blood donation system in gene polymorphism distribution of HPA - 3, 2 and 5 a and b gene hybrid rate is higher.

  3. Platelets and cardiac arrhythmia

    Directory of Open Access Journals (Sweden)

    Jonas S De Jong

    2010-12-01

    Full Text Available Sudden cardiac death remains one of the most prevalent modes of death in industrialized countries, and myocardial ischemia due to thrombotic coronary occlusion is its primary cause. The role of platelets in the occurrence of SCD extends beyond coronary flow impairment by clot formation. Here we review the substances released by platelets during clot formation and their arrhythmic properties. Platelet products are released from three types of platelet granules: dense core granules, alpha-granules, and platelet lysosomes. The physiologic properties of dense granule products are of special interest as a potential source of arrhythmic substances. They are released readily upon activation and contain high concentrations of serotonin, histamine, purines, pyrimidines, and ions such as calcium and magnesium. Potential arrhythmic mechanisms of these substances, e.g. serotonin and high energy phosphates, include induction of coronary constriction, calcium overloading, and induction of delayed after-depolarizations. Alpha-granules produce thromboxanes and other arachidonic acid products with many potential arrhythmic effects mediated by interference with cardiac sodium, calcium and potassium channels. Alpha-granules also contain hundreds of proteins that could potentially serve as ligands to receptors on cardiomyocytes. Lysosomal products probably do not have an important arrhythmic effect. Platelet products and ischemia can induce coronary permeability, thereby enhancing interaction with surrounding cardiomyocytes. Antiplatelet therapy is known to improve survival after myocardial infarction. Although an important part of this effect results from prevention of coronary clot formation, there is evidence to suggest that antiplatelet therapy also induces anti-arrhythmic effects during ischemia by preventing the release of platelet activation products.

  4. Inhibiting platelets aggregation could aggravate the acute infection caused by Staphylococcus aureus.

    Science.gov (United States)

    Zhang, Xin; Liu, Yu; Gao, Yaping; Dong, Jie; Mu, Chunhua; Lu, Qiang; Shao, Ningsheng; Yang, Guang

    2011-01-01

    Several fibrinogen binding proteins (Fibs) play important roles in the pathogenesis of Staphylococcus aureus (S. aureus). Most Fibs can promote the aggregation of platelets during infection, but the extracellular fibrinogen-binding protein (Efb) is an exception. It is reported that Efb can specifically bind fibrinogen and inhibit the aggregation of platelet with its N terminal. However, the biological significance of platelet aggregation inhibition in the infection caused by S. aureus is unclear until now. Here, we demonstrated that the persistence and aggregation of platelets were important for killing S. aureus in whole blood. It was found that the N terminal of Efb (EfbN) and platelets inhibitors could increase the survival of S. aureus in whole blood. The study in vivo also showed that EfbN and platelets inhibitors could reduce the killing of S. aureus and increase the lethality rate of S. aureus in the acute infection mouse model.

  5. Reduced platelet-mediated and enhanced leukocyte-mediated fibrinolysis in experimentally induced diabetes in rats

    Energy Technology Data Exchange (ETDEWEB)

    Winocour, P.D.; Colwell, J.A.

    1985-05-01

    Studies of fibrinolytic activity in diabetes mellitus have produced conflicting results. This may be a result of methodologic insensitivity or of variable contributions of the different blood components to whole blood fibrinolysis. To explore these two possibilities, the authors used a sensitive solid-phase radiometric assay to examine the fibrinolytic activity of whole blood, platelet-rich plasma, leukocytes, and platelet- and leukocyte-poor plasma prepared from control rats and rats with streptozocin-induced diabetes at various times after induction of diabetes. Fibrinolytic activity of whole blood from diabetic rats after 7 days was significantly reduced, and remained reduced after longer durations of diabetes up to 28 days. Platelet-rich plasma from diabetic rats had decreased fibrinolytic activity, which followed the same time course of changes as in whole blood. The platelet contribution to whole blood fibrinolysis was further reduced in vivo after 14 days of diabetes by a reduced whole blood platelet count. In contrast, fibrinolytic activity of leukocytes from diabetic rats became enhanced after 7 days of diabetes. After 49 days of diabetes, the whole blood leukocyte count was reduced, and in vivo would offset the enhanced activity. Plasma fibrinolytic activity was small compared with that of whole blood and was unaltered in diabetic rats. The authors conclude that altered platelet function contributes to decreased fibrinolytic activity of whole blood in diabetic rats, and that this may be partially offset by enhanced leukocyte-mediated fibrinolysis.

  6. Platelets stimulate fibroblast-mediated contraction of collagen gels

    Directory of Open Access Journals (Sweden)

    Lundahl Joachim

    2003-10-01

    Full Text Available Abstract Background Platelets are thought to play a role in a variety of inflammatory conditions in the lung, some of which may lead to fibrosis. In the current study we tested the hypothesis that whole platelets and platelet lysate can mediate remodelling of extracellular matrix in vitro by affecting fibroblast-mediated contraction of a collagen gel. We also sought to determine to what extent platelet-derived growth factor (PDGF and transforming growth factor-β (TGF-β contribute to this effect. Methods Washed platelets, isolated from healthy blood donors, and platelet lysate (freezing and thawing, were cast together with human lung fibroblasts in three-dimensional collagen gels. The gels were then released and cultured for four days. PDGF and TGF-β1 concentrations were measured in culture supernatants by ELISA. Results Both platelets and platelet lysate augmented fibroblast-mediated gel contraction in a time and concentration dependent manner (19.9% ± 0.1 (mean ± SEM of initial area vs. 48.0% ± 0.4 at 48 hours; P 1 and PDGF-AA/AB were released in co-culture. PDGF-AA/AB had a maximum release at 24 hours whereas TGF-β1 release increased with longer culture periods. Neutralising antibodies to these mediators partially inhibited platelet-induced gel contraction. Conclusion We conclude that platelets may promote remodelling of extracellular matrix in vitro and that PDGF and TGF-β partially mediate this effect, also indicating a role for other mediators. The findings may be an important mechanism in regulating repair processes after injury.

  7. A novel thrombopoietin signaling defect in polycythemia vera platelets.

    Science.gov (United States)

    Moliterno, A R; Siebel, K E; Sun, A Y; Hankins, W D; Spivak, J L

    1998-01-01

    The pathogenesis of polycythemia vera (PV), a disease involving a multipotent hematopoietic progenitor cell, is unknown. Thrombopoietin (TPO) is a newly characterized hematopoietic growth factor which regulates the production of multipotent hematopoietic progenitor cells as well as platelets. To evaluate the possibility that an abnormality in TPO-mediated signal transduction might be involved in the pathogenesis of PV, we examined TPO-induced protein tyrosine phosphorylation using platelets as a surrogate model system. Platelets were isolated from the blood of patients with PV as well as from patients with other chronic myeloproliferative disorders and control subjects. Impaired TPO-mediated platelet protein tyrosine phosphorylation was a consistent observation in patients with PV as well as those with idiopathic myelofibrosis (IMF), in contrast to patients with essential thrombocytosis, chronic myelogenous leukemia, secondary erythrocytosis, iron deficiency anemia, hemochromatosis, or normal volunteers. Thrombin-mediated platelet protein tyrosine phosphorylation was intact in PV platelets as was expression of the appropriate tyrosine kinases and their cognate substrates. However, expression of the platelet TPO receptor, Mpl, as determined by immunoblotting, chemical crosslinking or flow cytometry was markedly reduced or absent in 34 of 34 PV patients and also in 13 of 14 IMF patients. Impaired TPO-induced protein tyrosine phosphorylation in PV and IMF platelets was uniformly associated with markedly reduced or absent expression of Mpl. We conclude that reduced expression of Mpl is a phenotypic characteristic of platelets from patients with PV and IMF. The abnormality appears to distinguish PV from other forms of erythrocytosis and may be involved in the platelet function defect associated with PV.

  8. HMGB1 binds to activated platelets via the receptor for advanced glycation end products and is present in platelet rich human coronary artery thrombi.

    Science.gov (United States)

    Ahrens, Ingo; Chen, Yung-Chih; Topcic, Danijal; Bode, Michael; Haenel, David; Hagemeyer, Christoph E; Seeba, Hannah; Duerschmied, Daniel; Bassler, Nicole; Jandeleit-Dahm, Karin A; Sweet, Matthew J; Agrotis, Alex; Bobik, Alex; Peter, Karlheinz

    2015-11-01

    High mobility group box 1 (HMGB1) acts as both a nuclear protein that regulates gene expression, as well as a pro-inflammatory alarmin that is released from necrotic or activated cells. Recently, HMGB1-expression in human atherosclerotic plaques was identified. Therapeutic blockade of HMGB1 reduced the development of diet-induced atherosclerosis in ApoE knockout mice. Thus, we hypothesised an interaction between HMGB1 and activated platelets. Binding of recombinant HMGB1 to platelets was assessed by flow cytometry. HMGB1 bound to thrombin-activated human platelets (MFI 2.49 vs 25.01, p=0.0079). Blood from wild-type, TLR4 and RAGE knockout mice was used to determine potential HMGB1 receptors on platelets. HMGB1 bound to platelets from wild type C57Bl6 (MFI 2.64 vs 20.3, p 0.05). RAGE expression on human platelets was detected by RT-PCR with mRNA extracted from highly purified platelets and confirmed by Western blot and immunofluorescence microscopy. Platelet activation increased RAGE surface expression (MFI 4.85 vs 6.74, p< 0.05). Expression of HMGB1 in human coronary artery thrombi was demonstrated by immunohistochemistry and revealed high expression levels. Platelets bind HMGB1 upon thrombin-induced activation. Platelet specific expression of RAGE could be detected at the mRNA and protein level and is involved in the binding of HMGB1. Furthermore, platelet activation up-regulates platelet surface expression of RAGE. HMGB1 is highly expressed in platelet-rich human coronary artery thrombi pointing towards a central role for HMGB1 in atherothrombosis, thereby suggesting the possibility of platelet targeted anti-inflammatory therapies for atherothrombosis.

  9. Effects of the breed, sex and age on cellular content and growth factor release from equine pure-platelet rich plasma and pure-platelet rich gel

    OpenAIRE

    Giraldo Carlos E; López Catalina; Álvarez María E; Samudio Ismael J; Prades Marta; Carmona Jorge U

    2013-01-01

    Abstract Background There is no information on the effects of the breed, gender and age on the cellular content and growth factor (GF) release from equine pure-platelet rich plasma (P-PRP) and pure-platelet rich gel (P-PRG). The objectives of this study were: 1) to compare the cellular composition of P-PRP with whole blood and platelet poor plasma (PPP); 2) to compare the concentration of transforming GF beta 1 (TGF-β1) and platelet derived GF isoform BB (PDGF-BB) between P-PRP treated with n...

  10. Platelet Activation in Human Immunodeficiency Virus Type-1 Patients Is Not Altered with Cocaine Abuse.

    Directory of Open Access Journals (Sweden)

    Michelle Kiebala

    Full Text Available Recent work has indicated that platelets, which are anucleate blood cells, significantly contribute to inflammatory disorders. Importantly, platelets also likely contribute to various inflammatory secondary disorders that are increasingly associated with Human Immunodeficiency Virus Type-1 (HIV infection including neurological impairments and cardiovascular complications. Indeed, HIV infection is often associated with increased levels of platelet activators. Additionally, cocaine, a drug commonly abused by HIV-infected individuals, leads to increased platelet activation in humans. Considering that orchestrated signaling mechanisms are essential for platelet activation, and that nuclear factor-kappa B (NF-κB inhibitors can alter platelet function, the role of NF-κB signaling in platelet activation during HIV infection warrants further investigation. Here we tested the hypothesis that inhibitory kappa B kinase complex (IKK activation would be central for platelet activation induced by HIV and cocaine. Whole blood from HIV-positive and HIV-negative individuals, with or without cocaine abuse was used to assess platelet activation via flow cytometry whereas IKK activation was analyzed by performing immunoblotting and in vitro kinase assays. We demonstrate that increased platelet activation in HIV patients, as measured by CD62P expression, is not altered with reported cocaine use. Furthermore, cocaine and HIV do not activate platelets in whole blood when treated ex vivo. Finally, HIV-induced platelet activation does not involve the NF-κB signaling intermediate, IKKβ. Platelet activation in HIV patients is not altered with cocaine abuse. These results support the notion that non-IKK targeting approaches will be better suited for the treatment of HIV-associated inflammatory disorders.

  11. Kinetics and sites of sequestration of indium 111-labeled human platelets during cardiopulmonary bypass

    Energy Technology Data Exchange (ETDEWEB)

    Hope, A.F.; Heyns, A.D.; Loetter, M.G.; van Reenen, O.R.; de Kock, F.; Badenhorst, P.N.; Pieters, H.; Kotze, H.; Meyer, J.M.; Minnaar, P.C.

    1981-06-01

    A new approach for the study of the kinetics and quantification of the in vivo and ex vivo sites of sequestration of platelets during cardiopulmonary bypass (CPB) is described. Autologous platelets of four patients were labeled with /sup 111/In-oxine and reinfused on the day prior to CPB for coronary artery bypass grafting. Changes in blood /sup 111/In-labeled platelet radioactivity and blood platelet counts were monitored during the operation. In vivo /sup 111/In-labeled platelet redistribution was quantified with a scintillation camera and a computer-assisted imaging system before and after CPB. Sequestration of /sup 111/In-labeled platelets in the bubble oxygenator was measured. /sup 111/In-labeled platelet activity in the blood decreased by 46% +/- 5% within 5 minutes of CPB, but this decrease was mostly due to hemodilution; the true loss of platelets from the circulation was 13% +/- 4%. Intraoperatively, whole body /sup 111/In activity decreased by oxygenator 10.8% +/- 1.3% of administered platelets were sequestered, especially in the innermost active layers of the defoaming mesh of the bubble oxygenator. Mean survival time of circulating platelets was 58 +/- 8 hours and fitted an exponential function best. The bleeding time increased to 40 minutes during operation and returned to normal within 24 hours. During operation /sup 111/In-labeled platelets accumulated somewhat in the liver (10.7%) but not in the spleen, thorax, or head. In the 48 hours after operation, platelets were sequestered mainly in the liver. The scintillation camera with computer-assisted imaging allows in vivo quantitative studies of platelet kinetics of a type which has not been possible with previous techniques.

  12. The Platelet and Platelet Function Testing in Liver Disease

    NARCIS (Netherlands)

    Hugenholtz, Greg G. C.; Porte, Robert J.; Lisman, Ton

    2009-01-01

    Patients who have liver disease commonly present with alterations in platelet number and function. Recent data have questioned the contribution of these changes to bleeding complications in these patients. Modern tests of platelet function revealed compensatory mechanisms for the decreased platelet

  13. Migration distance-based platelet function analysis in a microfluidic system

    OpenAIRE

    Song, Suk-Heung; Lim, Chae-Seung; Shin, Sehyun

    2013-01-01

    Aggregation and adhesion of platelets to the vascular wall are shear-dependent processes that play critical roles in hemostasis and thrombosis at vascular injury sites. In this study, we designed a simple and rapid assay of platelet aggregation and adhesion in a microfluidic system. A shearing mechanism using a rotating stirrer provided adjustable shear rate and shearing time and induced platelet activation. When sheared blood was driven through the microchannel under vacuum pressure, shear-a...

  14. Incidence of platelet dysfunction by thromboelastography-platelet mapping in children supported with ECMO: A Pilot Retrospective Study.

    Directory of Open Access Journals (Sweden)

    Arun eSaini

    2016-01-01

    Full Text Available Background: Bleeding complications are common and decrease the odds of survival in children supported with extracorporeal membrane oxygenation (ECMO. The role of platelet dysfunction on ECMO-induced coagulopathy and resultant bleeding complications is not well understood. The primary objective of this pilot study was to determine the incidence and magnitude of platelet dysfunction according to thromboelastography (TEG®-platelet mapping (PM testing. Methods: Retrospective chart review of children <18 years old who required ECMO at a tertiary level hospital. We collected TEG®-PM and conventional coagulation tests data. We also collected demographic, medications, blood products administered, and clinical outcome data. We defined severe platelet</