The effect of dermatan sulfate on in vitro human plasma coagulation, platelet aggregation and βTG/PF4 release

1990 ◽  
Vol 57 (3) ◽  
pp. 405-414 ◽  
Author(s):  
E. Cofrancesco ◽  
M. Colombi ◽  
F. Gianese ◽  
M. Cortellaro
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Dermatan Sulfate ◽  
Plasma Coagulation

C0135 In vitro and in silico study of the effect of crocin and safranal on human plasma coagulation

2012 ◽  
Vol 130 ◽  
pp. S167
Author(s):  
Maria Ditsa ◽  
George Geromihalos ◽  
Eleftheria Tragoulia ◽  
Dimitra Markala ◽  
Chrisa Meleti ◽  
...  
Keyword(s):  
Human Plasma ◽  
In Silico ◽  
Plasma Coagulation ◽  
In Silico Study

Comparison of different anticoagulant associations on haemostasis and biochemical analyses in feline blood specimens

2016 ◽  
Vol 19 (4) ◽  
pp. 394-402 ◽  
Author(s):  
Fanny Granat ◽  
Céline Monzali ◽  
Elisabeth Jeunesse ◽  
Maud Guerlin ◽  
Catherine Trumel ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Divalent Cations ◽  
A Priori ◽  
Clinical Pathology ◽  
Reference Intervals ◽  
Poor Correlation ◽  
Aminotransferase Activity ◽  
Plasma Coagulation ◽  
Blood Specimens

Objectives Universal anticoagulant could be an alternative to the multiple blood sampling required for clinical pathology investigations in cats. An association of citrate, theophylline, adenosine and dipyridamole (CTAD) has been reported to be a good substitute for EDTA for haematology analysis in cats, limiting platelet clumping, and has also been shown to be valid for haematology, secondary haemostasis and some biochemical variables in humans. The aim of the study was therefore to investigate the effects of CTAD on in vitro platelet aggregation and compare results of secondary haemostasis and biochemistry tests, excluding a priori those variables not reliably measured in CTAD, such as sodium, chloride and divalent cations, in feline blood specimens collected in CTAD and paired citrate and heparin tubes. Methods Thirty blood specimens sampled in citrate and CTAD were analysed for in vitro platelet aggregation, and 60 blood specimens sampled in citrate or heparin and CTAD were analysed for plasma coagulation and a biochemistry panel. Results In vitro platelet aggregation was inhibited in CTAD compared with citrate specimens. Prothrombin time, activated partial thromboplastin time, antithrombin and fibrinogen results were similar, despite some significant differences. Measurements of triglycerides, cholesterol, glucose, urea, creatinine, phosphate, total proteins and alanine aminotransferase activity were similar and well correlated in CTAD and heparin plasmas, despite some significant differences and moderate biases. Albumin showed a marked positive proportional bias, and creatine kinase and alkaline phosphatase activities a moderate and marked negative mixed bias, respectively, but could be measured in CTAD if new reference intervals were calculated. Aspartate aminotransferase activity showed a marked negative proportional bias, along with a poor correlation and some clinical misclassifications just like the potassium concentration, and thus cannot be recommended to be measured in CTAD specimens. Conclusions and relevance In cats, CTAD cannot be used for primary haemostasis investigation but could be a suitable (almost) universal anticoagulant for routine haematology, as well as for plasma coagulation and many biochemistry variables.

Endothelial Microparticles Improve Primary and Secondary Hemostasis in Patients with Von-Willebrand Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2287-2287
Author(s):  
Arne Trummer ◽  
Ingvild Birschmann ◽  
Sonja Werwitzke ◽  
Arnold Ganser ◽  
Andreas Tiede
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Thrombin Generation ◽  
Conflicts Of Interest ◽  
Annexin V ◽  
Von Willebrand Disease ◽  
Endothelial Microparticles ◽  
Circulating Microparticles ◽  
Von Willebrand

Abstract Abstract 2287 The bleeding phenotype in patients with von Willebrand disease (vWD) type 1 and 3 can usually be correlated to the amount and function of von Willebrand factor (vWF:Ag, vWF:RCo) but also to the impairment of functional coagulation assays: the ristocetin-induced platelet aggregation (RIPA) for primary hemostasis and the parameters of thrombin generation in a calibrated automated thrombogram (CAT, Thrombinoscope®) for secondary hemostasis. We therefore evaluated whether addition and depletion of endothelial microparticles (EMP) might influence these assays for samples of vWD patients. EMP were obtained from stimulated endothelial cell lines, isolated either by ultracentrifugation or magnetic beads selection for Annexin V and detected and quantified by flow cytometry after labelling for Annexin V and vWF. For CAT, EMP concentration was adjusted to 3×103/μl, for RIPA to 2×104/μl. vWD patient samples were diluted 3:1 or 2:1 with control buffer (HEPES/CaCl) or EMP solution. For thrombin generation, there was a significant shortening of lag time (6.8min vs 16.5min, p=.029) and time-to-peak (13.6min vs. 23.0min, p=.049) in vWD type 3 plasma (n=4) after addition of EMP using no reagent or MP reagent while there was no significant effect on these parameters in normal plasma. After addition of a tissue factor blocking antibody, the EMP effect could be largely reversed. For RIPA, we found a median maximum aggregation of 4% in vWD patients (n=6, vWF-Ag <40%). After addition of EMP, aggregation levels increased to 17.3%, which was significantly higher compared to control buffer (9.8%, p=.028), but lower compared to 250 IU/ml of a plasma-derived vWF product (Humate P®, 88.7%). To evaluate if significant amounts of vWF are bound to circulating microparticles in human plasma, we used magnetic bead selection to reduce MP counts in plasma of DDAVP stimulated vWD patients (n=10), because depletion of microparticles by 0.2μm filtration showed significant disruption of large vWF multimers. After MP reduction (1464/μl vs. 1863/μl, p=.036), both vWF:Ag (134.7% vs 161.1%, p=.005) and vWF:RCo (131.8% vs. 167.2%, p=.017) were significantly decreased. In summary, we could show that in vitro generated endothelial microparticles are able to improve thrombin generation and platelet aggregation in vWD patients and that significant amounts of vWF are bound to circulating microparticles in human plasma after DDAVP stimulation. Thus, in vitro generated EMP might have the potential to improve replacement therapy for vWD patients. Disclosures: No relevant conflicts of interest to declare.

Experimental Venous Thrombosis in the Rat

1963 ◽  
Vol 10 (01) ◽  
pp. 202-213 ◽  
Author(s):  
Arne Nordöy
Keyword(s):  
Venous Thrombosis ◽  
Human Plasma ◽  
Jugular Vein ◽  
Thrombus Formation ◽  
Thrombocyte Count ◽  
Plasma Coagulation ◽  
Plasma Fraction ◽  
Global Tests ◽  
The Mean

Summary1. The effect of erythremia and thrombocythemia on thrombus formation has been examined in rats using a standardized operation on the jugular vein. In control animals the incidence of thrombosis was 30’% ( ± 4.6 S. E.).2. Hypoxic induced erythremia increased the incidence of thrombosis (53% — p <C 0.05). The mean hematocrit value in this group was 62.3. An increase in the thrombocyte count with 34%, produced by giving a thermostable human plasma fraction to normal rats, did not significantly increase the incidence of thrombosis (40%).4. An increase in the thrombocyte count with 26% in erythremic animals increased the incidence of thrombosis nearly twice (56%, p <C 0.05).5. The global tests for plasma coagulation, the fibrinogen levels and the antifibrinolytic activity of plasma were not significantly influenced by the conditions examined.6. The number of adhesive platelets measured in vitro increased in the animals with erythremia.

Effects of Puff Adder Venom on the Coagulation Mechanism

1973 ◽  
Vol 30 (03) ◽  
pp. 499-508 ◽  
Author(s):  
Louise L. Phillips ◽  
H. J Weiss ◽  
N. P Christy
Keyword(s):  
Platelet Aggregation ◽  
Human Plasma ◽  
Coagulation System ◽  
Factor Xi ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Normal Plasma ◽  
Coagulation Mechanism ◽  
In Vitro Effects

SummaryStudies of the in vitro effects of puff adder venom (Bitis arietans) on the coagulation system of human plasma have suggested this venom activates factor XI. Incubation with the venom results in a prolongation of the partial thromboplastin times in glass which is associated with a depletion of factors V, VIII, and fibrinogen. The latter may be due to the proteolytic properties of the venom. Soluble fibrin monomer complexes are formed rapidly after addition of the venom to normal plasma. The venom also causes platelet aggregation which is not inhibited by heparin.

Dermatan Sulfate and LMW Heparin Enhance the Anticoagulant Action of Activated Protein C

1999 ◽  
Vol 82 (11) ◽  
pp. 1462-1468 ◽  
Author(s):  
José Fernández ◽  
Jari Petäjä ◽  
John Griffin
Keyword(s):  
Molecular Weight ◽  
Unfractionated Heparin ◽  
Protein C ◽  
Dermatan Sulfate ◽  
Anticoagulant Activity ◽  
Activated Protein C ◽  
Factor V ◽  
Factor Va ◽  
Anticoagulant Action

SummaryUnfractionated heparin potentiates the anticoagulant action of activated protein C (APC) through several mechanisms, including the recently described enhancement of proteolytic inactivation of factor V. Possible anticoagulant synergism between APC and physiologic glycosaminoglycans, pharmacologic low molecular weight heparins (LMWHs), and other heparin derivatives was studied. Dermatan sulfate showed potent APC-enhancing effect. Commercial LMWHs showed differing abilities to promote APC activity, and the molecular weight of LMWHs correlated with enhancement of APC activity. Degree of sulfation of the glycosaminoglycans influenced APC enhancement. However, because dextran sulfates did not potentiate APC action, the presence of sulfate groups per se on a polysaccharide is not sufficient for APC enhancement. As previously for unfractionated heparin, APC anticoagulant activity was enhanced by glycosaminoglycans when factor V but not factor Va was the substrate. Thus, dermatan sulfate and LMWHs exhibit APC enhancing activity in vitro that could be of physiologic and pharmacologic significance.

Effect of Temperature on ADP-Induced Platelet Aggregation

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani
Keyword(s):  
Platelet Aggregation ◽  
Incubation Period ◽  
Room Temperature ◽  
Important Variable ◽  
Practical Significance ◽  
Effect Of Temperature ◽  
Induce Platelet Aggregation ◽  
Cuvette Holder ◽  
Exact Temperature

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.

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