scholarly journals Features of Microparticle-Associated Procoagulant Activity in Patients with Thrombocytopenias of Immune and Central Origin

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1462-1462
Author(s):  
Nora V. Butta ◽  
M T Alvarez Román ◽  
Ihosvany Fernández Bello ◽  
Elena Arias-Salgado ◽  
Raquel de Paz ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Platelet Count ◽  
Plasma Levels ◽  
Procoagulant Activity ◽  
Monocyte Count ◽  
Red Cell ◽  
Control Groups ◽  
Platelet Destruction ◽  
Central Origin ◽  
And Control

Abstract Introduction: The risk of bleeding in patients with thrombocytopenia is increased with platelet counts less than 20 or 30 x 109/L. Nevertheless, some patients with thrombocytopenia of peripheral and central origin (immune thrombocytopenia [ITP] and myelodysplastic syndromes [MDS] respectively) have fewer bleeding symptoms than expected. This fact suggests there may be compensatory mechanisms for the thrombocytopenia, such as the presence of microparticles (MPs). Objective: The aim of this study was to evaluate and characterize the microparticle-associated procoagulant activity in ITP and MDS patients with thrombocytopenia. Methods: Thirty-five patients with chronic ITP and twenty-six patients with MDS with a platelet count less than 50 x109/L and twenty-five healthy controls were included. Blood cell counts were determined with a Coulter Ac. T Diff cell counter (Beckman Coulter, Madrid, Spain). Citrated blood was centrifuged at 1,500 g for 15 min at 23°C. Platelet-poor plasma obtained was additionally centrifuged twice at 23°C (15 min at 1,500 g, and 2 min at 13,000 g, [PFP]) and aliquots were stored at -70ºC until analysis. Phosphatidylserine-MP (Ph-MP) and tissue factor-MP (TF-MP)-dependent procoagulant activities were determined with the ZYMUPHEN kits (Hyphen BioMed, Neuville sur Oise, France) following the manufacturer’s instructions. The identification of MP’s cell origin was determined by flow cytometry labeling MPs with Annexin-V-fluorescein and the following specific monoclonal antibodies (mAb) conjugated with phycoerythrin: anti CD41 mAb for platelets, anti CD14 mAb for monocytes, anti CD144 mAb for endothelial cells, anti CD235 mAb for red cells and anti CD45 mAb for leukocytes. APRIL plasma levels were determined by ELISA (DuoSet ELISA, R&D Systems, Minneapolis, MN, USA). Results: Ph-MP associated procoagulant capacity in MDS and ITP patients was higher than in controls (p<0.01) whereas MP-TF associated procoagulant activity was only increased in MDS patients and practically negligible in ITP and control groups (p<0.01). MPs analysis by flow cytometry of seventeen controls, twenty ITP and six MDS patients showed that ITP patients had an increased percentage of MPs from platelets and red cells, whereas MDS had an increased percentage of monocytes derived MPs. Proportion of MPs derived from other cell types were similar to the control group. Increased percentage of monocyte-derived MPs in MDS patients is in accordance with the higher MP-TF-associated capacity observed in this group since monocytes are tissue factor rich cells. Nevertheless, no differences were found in monocyte count with control and ITP groups and monocyte count did not correlate with MPs associated procoagulant activity and the percentage of monocyte-derived MPs. In the ITP group neither MP-Ph-associated procoagulant activity nor the percentage of red cell-derived MPs correlated with red cell count. On the contrary, MP-Ph-associated procoagulant activity and the percentage of platelet-derived MPs inversely correlated with platelet count. ITP is an antibody-mediated autoimmune disease characterized by accelerated platelet destruction. A proliferation-inducing ligand (APRIL) is a factor that promotes B-cell maturation and survival. All patients with ITP and thrombocytopaenia showed higher APRIL plasma levels than MDS and control groups (p<.01), which inversely correlated with platelet count and correlated to MP-Ph-associated procoagulant activity. These observations support the proposed pathogenic role of APRIL in the development of this disease and that the increase in platelet-derived MPs was due to peripheral platelet destruction. Conclusion: Peripheral and central thrombocytopenias might present a MP-associated procoagulant activity to compensate bleeding risk present in these patients. Cellular origin of these MPs differed according to thrombocytopaenia etiology. Disclosures No relevant conflicts of interest to declare.

scholarly journals Full-Length Transcriptome Sequencing: An Insight Into the Dog Model of Heart Failure

2021 ◽  
Vol 8 ◽  
Author(s):  
Xiaoyan Liang ◽  
Zechen Bai ◽  
Feifei Wang ◽  
Yafan Han ◽  
Huaxin Sun ◽  
...  
Keyword(s):  
Heart Failure ◽  
Flow Cytometry ◽  
Th17 Cell ◽  
Transcriptome Sequencing ◽  
Full Length ◽  
Control Groups ◽  
Qrt Pcr ◽  
Dog Model ◽  
Th17 Cell Differentiation ◽  
And Control

Heart failure (HF) leads to a progressive increase in morbidity and mortality rates. This study aimed to explore the transcriptional landscape during HF and identify differentially expressed transcripts (DETs) and alternative splicing events associated with HF. We generated a dog model of HF (n = 3) using right ventricular pacemaker implantation. We performed full-length transcriptome sequencing (based on nanopore platform) on the myocardial tissues and analyzed the transcripts using differential expression analysis and functional annotation methods [Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses]. Additionally, we estimated the expression of the selected genes by quantitative real-time PCR (qRT-PCR) and detected the proportion of immune cells using flow cytometry. We found that increased B-type natriuretic peptide reduced ejection fraction, and apparent clinical signs were observed in the dog model of HF. We identified 67,458 transcripts using full-length transcriptome sequencing. A total of 785 DETs were obtained from the HF and control groups. These DETs were mainly enriched in the immune responses, especially Th1, Th2, and Th17 cell differentiation processes. Furthermore, flow cytometry results revealed that the proportion of Th1 and Th17 cells increased in patients with HF compared to controls, while the proportion of Th2 cells decreased. Differentially expressed genes in the HF and control groups associated with Th1, Th2, and Th17 cell differentiation were quantified using qRT-PCR. We also identified variable splicing events of sarcomere genes (e.g., MYBPC3, TNNT2, TTN, FLNC, and TTNI3). In addition, we detected 4,892 transcription factors and 406 lncRNAs associated with HF. Our analysis based on full-length transcript sequencing provided an analysis perspective in a dog model of HF, which is valuable for molecular research in an increasingly relevant large animal model of HF.

scholarly journals Assessment of Platelet Indices Profile of Pregnant Women Attending University of Abuja Teaching Hospital, Nigeria

2021 ◽  
Vol 3 (2) ◽  
pp. 99-108
Author(s):  
Amos Dangana ◽  
Anthony Uchenna Emeribe ◽  
Hezekiah Alkali Isah ◽  
Sanusi Musa ◽  
Joel Monday Abu ◽  
...  
Keyword(s):  
Platelet Count ◽  
Pregnant Women ◽  
Teaching Hospital ◽  
Control Group ◽  
Control Groups ◽  
Distribution Width ◽  
Significant Difference ◽  
Endothelial Integrity ◽  
The University ◽  
And Control

Platelets initiate hemostasis by aggregating at the site of injury and participate in ensuring endothelial integrity. A defect in this process could lead to intravascular blood loss. This case-control study sought to determine the platelet counts and indices among pregnant women in the University of Abuja Teaching Hospital Gwagwalada, Abuja, Nigeria. A total of 120 pregnant women as case and 60 non-pregnant women as control were enrolled for this study. Blood samples were collected in EDTA tubes, and complete platelet count and indices were carried out using an automated five-part haematology analyzer. The mean ± standard deviation of the platelets count among the pregnant women, 226.54 ± 69.76 109 cells/L was not significantly different from that of the non-pregnant women, 214.95 ± 52.22x 109 cells/L (p=0.295). There was a significant differences in mean platelets volume (MPV) of the case and control groups (p=0.036). After post-hoc test, the significant difference was between the  pregnant women in 3rd trimester and the control group (p=0.014). However, there was no diffences in the mena platelets larger cell ratio and platelet distribution width in the case and control groups. Fifteen (11.0%) and 7 (12.1%) of the case and control control groups, respectively had mild thrombocytopenia. However, there was no significant association between pregnant status and thrombocytopenia (p=0.836). Based on these findngs, it can be infered that platelet count and MPV decreases while PDW increase with the progression of gestation age compared to the non-pregnant women.

scholarly journals Platelet Features from ITP Patients Responders to Different Therapeutic Treatments

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4648-4648
Author(s):  
Nora Butta ◽  
María Isabel Rivas Pollmar ◽  
María Teresa Álvarez Román ◽  
Monica Martín Salces ◽  
Ihosvany Fernandez Bello ◽  
...  
Keyword(s):  
Platelet Count ◽  
Plasma Levels ◽  
Conflicts Of Interest ◽  
Annexin V ◽  
Procoagulant Activity ◽  
Control Group ◽  
Severe Bleeding ◽  
Healthy Controls ◽  
Platelet Counts ◽  
Before And After

Abstract Background: Patients with ITP have a wide variation in the presentation of the disease, platelet count and their clinical course. The decision to begin treatment is based on the hemorrhagic symptoms and platelet count. Intravenous immunoglobulin (IVIG) is usually associated with glucocorticoid administration in patients with severe bleeding or platelet counts <20x109/L and a quick response is required. Agonists of thrombopoietin receptor (TPO-AR) and splenectomy are other therapeutic tools for these patients. Materials and Methods: We recruited patients with ITP before and after responding to treatment with IVIG (n = 11) and AR-TPO (4 patients with romiplostim and 10 with eltrombopag), 5 splenectomized patients and 82 healthy controls. The percentage of reticulated platelets, platelet activation and binding of annexin-V were evaluated by flow cytometry. Plasma levels of TPO and "a proliferation-inducing ligand" (APRIL) were determined by ELISA. Procoagulant activity associated microparticles (MP) and the ability of plasma to generate thrombin were determined, respectively, with Zymuphen kit and calibrated automated thrombinography (CAT) triggered by 1 pM tissue factor and 4 micromolar phospholipid (PPP-low reagent, Diagnostica Stago, Spain). Results: Patients with ITP that respond to IGIV and AR-TPO treatments recovered platelet counts without reaching the levels of the control group, whereas the platelet count in splenectomized patients did not differ from it. Plasma levels of TPO and the number of immature platelets in the first two groups were higher than in controls before responding to treatment. Despite recovering platelet count, platelet capacity of being activated by agonists such as TRAP (thrombin receptor agonist for PAR-1) was less than that of the controls in all groups. This decrease was not due to a reduction in the expression of the fibrinogen receptor on platelets from ITP patients. Platelets from ITP patients before and after responding to all treatments studied, showed more phosphatidylserine exposure and greater microparticles-associated and plasma-associated procoagulant activity. Plasma levels of APRIL, a factor that stimulates B cells and antibody production, decreased in ITP patients who responded to the AR-TPO, reaching the levels observed in the control group. In the group of splenectomized patients a decrease of APRIL was also observed, but still remained higher than in healthy controls. Conclusions: ITP patients who respond to treatment with IVIG and AR-TPO and undergoing splenectomy recovered platelet count but not its function. The treatments did not modify the microparticles- and plasma-associated thrombogenic capacity. Among all the treatments studied, AR-TPO and splenectomy had an addittional benefical effect reducing APRIL plasma levels Disclosures No relevant conflicts of interest to declare.

Conjugated Linoleic Acid Causes a Marked Increase in Liver α-Tocopherol and Liver α-Tocopherol Transfer Protein in C57BL/6 J Mice

2010 ◽  
Vol 80 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pei-Min Chao ◽  
Wan-Hsuan Chen ◽  
Chun-Huei Liao ◽  
Huey-Mei Shaw
Keyword(s):  
Antioxidant Enzymes ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Thiobarbituric Acid ◽  
Control Group ◽  
Thiobarbituric Acid Reactive Substances ◽  
Control Groups ◽  
Protein Levels ◽  
Transfer Protein ◽  
And Control

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.

PAICA: A Method for Characterizing Platelet-Associated Antibodies - Its Application to the Study of Idiopathic Thrombocytopenic Purpura and to the Detection of Platelet-bound c7E3

1996 ◽  
Vol 76 (06) ◽  
pp. 1020-1029 ◽  
Author(s):  
Laurent Macchi ◽  
Gisèle Clofent-Sanchez ◽  
Gérald Marit ◽  
Claude Bihour ◽  
Catherine Durrieu-Jais ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Idiopathic Thrombocytopenic Purpura ◽  
Antithrombotic Therapy ◽  
Membrane Glycoproteins ◽  
Serum Antibodies ◽  
Platelet Destruction ◽  
Thrombocytopenic Purpura ◽  
Capture Assay ◽  
Specific Membrane

SummaryIn idiopathic thrombocytopenic purpura (ITP), autoantibodies reacting with antigens on the platelet membrane bring about accelerated platelet destruction. We now report PAICA (“Platelet-Associated IgG Characterization Assay”), a method for detecting autoantibodies bound to specific membrane glycoproteins in total platelet lysates. This monoclonal antibody (MAb) capture assay takes into account the fact that antibodies on circulating platelets may be translocated to internal pools as well as being on the surface. A total of twenty ITP patients were examined by PAICA, and the results compared with those obtained by measuring (i) serum antibodies bound to paraformaldehyde-fixed control platelets by ELISA, (ii) IgG bound to the surface of the patient’s own platelets by flow cytometry (PSIgG), (iii) total platelet-associated IgG (PAIgG) by ELISA and (iv) serum antibodies reacting with control platelets by MAIPA (“Monoclonal Antibody-specific Immobilization of Platelet Antigens”). Of twelve patients with elevated PAIgG, nine had increased PSIgG yet eleven reacted positively in PAICA. Of these, eight possessed antibodies directed against GP Ilb-IIIa, two against GP Ib-IX and one patient possessed antibodies directed against GP Ilb-IIIa and GP Ia-IIa respectively. Only seven of the patients possessed serum antibodies detectable by MAIPA. PAICA was also able to detect platelet-associated c7E3 (the chimeric form of Fab fragments of the MAb 7E3) following its infusion during antithrombotic therapy, when it proved more sensitive over a seven-day period than a MAIPA assay adapted for assessing surface-bound antibody. We propose that PAICA provides added sensitivity to the detection of platelet-associated antibodies in immune thrombocytopenias or following therapy with humanized MAbs.

A Simple and Rapid Method to Determine GPIIb/IIIa-Receptor Inhibitor Activity in Whole Blood

1999 ◽  
Vol 19 (03) ◽  
pp. 134-138
Author(s):  
Gitta Kühnel ◽  
A. C. Matzdorff
Keyword(s):  
Flow Cytometry ◽  
Platelet Count ◽  
Blood Sample ◽  
Platelet Activation ◽  
Whole Blood ◽  
Receptor Occupancy ◽  
Aggregate Formation ◽  
Inhibitor Activity ◽  
Receptor Inhibitor

SummaryWe studied the effect of GPIIb/IIIa-inhibitors on platelet activation with flow cytometry in vitro. Citrated whole blood was incubated with increasing concentrations of three different GPIIb/IIIa-inhibitors (c7E3, DMP728, XJ757), then thrombin or ADP were added and after 1 min the sample was fixed. Samples without c7E3 but with 0.1 U/ml thrombin had a decrease in platelet count. Samples with increasing concentrations of c7E3 had a lesser or no decrease in platelet count. The two other inhibitors (DMP 725, XJ757) gave similar results. GPIIb/IIIa-inhibitors prevent aggregate formation and more single platelets remain in the blood sample. The agonist-induced decrease in platelet count correlates closely with the concentration of the GPIIb/IIIa inhibitor and receptor occupancy. This correlation may be used as a simple measure for inhibitor activity in whole blood.

The Involvement of Platelets and the Coronary Vasculature in Collagen-Induced Sudden Death in Rabbits

1985 ◽  
Vol 53 (01) ◽  
pp. 070-074 ◽  
Author(s):  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Platelet Count ◽  
Sudden Death ◽  
Myocardial Ischaemia ◽  
Plasma Levels ◽  
Sodium Citrate ◽  
Plasma Samples ◽  
Calcium Entry Blockers

SummaryThe mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TxB2) and 6-keto prostaglandin Fia (6-keto PGF1α). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBs), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TxB2 levels. 6-keto PGF1α could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TxB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KC1, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBs physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death.

The Prospects and Risks Connected with Increasing the Level of Self-Organisation in Students

2020 ◽  
pp. 75-81
Author(s):  
Svetlana Alexandrovna Kosareva ◽  
Keyword(s):  
Higher Education ◽  
Professional Competence ◽  
Initial Level ◽  
Education Institution ◽  
Diagnostic Methods ◽  
Study Guide ◽  
Learning Approaches ◽  
Control Groups ◽  
Self Organisation ◽  
And Control

The paper describes the method for increasing the level of self-organisation in students which has been developed by the author. It also contains the method testing results and presents the prospects and risks teachers could face while applying the method in a higher education institution. The purpose of this study is to find out the prospects and risks of applying the method for increasing the level of self-organisation in students and to determine the ways of reducing the risks. Methodology. The author points out the learning approaches which were the basis of developing the method and describes diagnostic methods for determining students’ self-organisation levels. The work focused on increasing each student’s initial level consists of a theoretical and a practical part and includes project activities on creating a study guide. The results of the study. The method developed proved to be effective. It was established by diagnosing the final level of self-organisation in students in the experimental and control groups. The paper considers the advantages of the method among which there is universal character, flexibility, improvements to teacher’s and students’ professional competence, etc. At the same time it is necessary to be aware of the risks due to the increased amount of teacher’s work and the fact that students’ work within the project tends to be monotonous. In conclusion, the prospects of the method for increasing the level of self-organisation in students are related to its advantages and the final results of the work. The risks of its use can be reduced with the help of the measures proposed in the paper.

Sri Lankan Cleft Lip and Palate Study Model Analysis: Clefts of the Secondary Palate

1993 ◽  
Vol 30 (2) ◽  
pp. 227-230 ◽  
Author(s):  
Andrew Mccance ◽  
David Roberts-Harry ◽  
Martyn Sherriff ◽  
Michael Mars ◽  
William J.B. Houston
Keyword(s):  
Cleft Lip ◽  
Cleft Lip And Palate ◽  
Model Analysis ◽  
Control Group ◽  
Tooth Size ◽  
Sri Lankan ◽  
Control Groups ◽  
Secondary Palate ◽  
Comparable Control ◽  
And Control

The study models of a group of adult Sri Lankan patients with clefts of the secondary palate were investigated. Tooth-size and arch-dimension comparisons were made with a comparable control group. Significant differences were found between the cleft and control groups in tooth sizes, chord lengths, and arch widths. The cleft group dimensions were generally smaller than those of the control group. Overjets were larger in the cleft group.

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