Detection of Abnormal Platelet Functions with an in vitro Model of Primary Haemostasis

Kratzer, M. A. A.; Bellucci, Sylvia; Caen, J

doi:10.1159/000215174

Cited by 32 publications

(27 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…When blood is passed through the aperture of the chamber bearing the collagen-coated membrane, plate let adhesion and growth of platelet thrombi are observed, similar to those events in in vivo hemostasis. The Thrombostat 4000 is an excellent device for detecting defects in pri mary hemostasis with a good reproducibility, and it was reported to detect abnormal plate let function at the time of platelet transfusion [15,16], thrombocytopenia [17,18], von Willebrand's disease [19] and in treatments with antiplatelet medications [20][21][22], Moreover, abnormal platelet function has been shown to correlate with an increased bleeding time in patients [23], Therefore, in this study, we compared the hemorrhage complications of heparin and APC with respect to platelet function after intravenous infusion of these anticoagulants into rabbits.…”

Section: Discussionmentioning

confidence: 99%

Comparison of Hemorrhagic Effect of Heparin and Human Activated Protein C with Use of Thrombostat 4000

Katsuura¹,

Tanabe²,

Kiyoki³

et al. 1996

Pathophysiol Haemos Thromb

View full text Add to dashboard Cite

The importance of bleeding as a complication of anticoagulant therapy is clearly recognized. We previously reported that amelioration of hemorrhage associated with disseminated in-travascular coagulation by the human activated protein C (APC) was greater than that by heparin. In this study, we compared the bleeding complication of intravenously administered APC and heparin in rabbits, and also estimated primary hemostasis. When both anticoagulants were intravenously infused, the bleeding time from a punctured ear vein was prolonged dose-dependently. However, at doses which prolonged the activated partial thromboplastin time nearly equally, the prolongation of bleeding was greater in heparin-administered rabbits. Blood withdrawn from heparin-administered animals showed increases in in vitro bleeding parameters which correlated with the in vivo bleeding time. However, only small changes were observed in the blood withdrawn from APC-administered animals. Both drugs induced either no change or only a slight decrease in the platelet count, hematocrit and fibrinogen content. These observations suggest that APC may be a more useful anticoagulant than heparin since it causes less bleeding tendency.

show abstract

Section: Discussionmentioning

confidence: 99%

Comparison of Hemorrhagic Effect of Heparin and Human Activated Protein C with Use of Thrombostat 4000

Katsuura¹,

Tanabe²,

Kiyoki³

et al. 1996

Pathophysiol Haemos Thromb

View full text Add to dashboard Cite

show abstract

“…When blood comes into contact with the membrane, platelets adhere, aggregate and form a plug that occludes the aperture and stops the blood flow. The time required to occlude the aperture is automatically reported as the closure time (CT) [27, 28]. …”

Section: Methodsmentioning

confidence: 99%

“…As aspirin does not prolong the ADP-induced CT [27, 30], we measured the collagen-ADP-induced CT in 9 patients receiving aspirin. The ADP-induced CT was also determined in 10 controls.…”

Section: Methodsmentioning

confidence: 99%

Statin Potentiates Human Platelet eNOS Activity without Enhancing eNOS mRNA and Protein Levels

Yemişçi

Kocaefe³

et al. 2008

Cerebrovasc Dis

View full text Add to dashboard Cite

Background/Aims: Experimental studies suggest an enhanced endothelial and platelet nitric oxide (NO) generation after statin treatment, possibly due to increased endothelial NO synthase (eNOS) activity and protein levels. In parallel with experimental research, statins were shown to increase the forearm blood flow independently of serum cholesterol in humans. However, it was not possible to correlate blood flow changes with eNOS levels in these studies due to limitations in obtaining arterial samples. Hence, we investigated changes in eNOS activity, mRNA and protein levels after statin treatment in human platelets, which are readily accessible unlike arteries. Methods: In vitro bleeding times were measured in 22 patients by stimulating platelets with collagen-epinephrine or collagen-ADP. To assess platelet eNOS activity, the bleeding times were also determined after incubating platelets with L-arginine. The measurements were repeated following 14 days of pravastatin (40 mg/day) treatment. Platelet-rich plasma was collected before and after statin treatment to evaluate eNOS mRNA (semiquantitative RT-PCR) and protein levels (Western blotting). Results: The basal bleeding time was prolonged by 24 ± 3% (mean ± SE) when the samples were incubated with 500 µM of L-arginine. The NOS inhibitor L-N⁵-(I-iminoethyl)ornithine reversed this effect, suggesting that it was mediated by NO. After statin treatment, the NO-mediated prolongation of the bleeding time with 500 µM of L-arginine was significantly potentiated (to 44 ± 10%). Despite enhanced eNOS activity, there was no significant change in platelet eNOS mRNA and protein levels after statin treatment. Conclusion: These data demonstrate that platelet eNOS activity is potentiated after statin treatment in humans in parallel with experimental studies.

show abstract

“…For this pur pose, the in vivo bleeding time (Ivy bleeding time test) has so far been the only reasonably accurate test. In 1985, Kratz erand Born [8] and Kratzer et al [9] described a new meth od for the determination of platelet function, the in vitro bleeding time (1VBT), mimicking the bleeding time. Citrated whole blood is passed through a capillary and a filter coated with collagen.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Platelet Function Using the in vitro Bleeding Time and Corrected Count Increment of Transfused Platelets

Eriksson¹,

Kristensen²,

Olsson³

et al. 1996

Vox Sanguinis

View full text Add to dashboard Cite

The functional capacity of transfused platelets was evaluated with in vitro bleeding time (IVBT) and corrected count increment (CCI) in order to compare platelet concentrates (PCs) derived from pooled buffy coats (BC-PCs) with PCs collected by apheresis (A-PCs). The suspension medium in the BC-PCs was 30% CPD plasma and 70% of an additive solution (containing sodium and potassium chloride, sodium citrate and phosphate, mannitol), and in the A-PCs the medium was 100% CPD plasma. IVBT was evaluated using a Thrombostat 4000/2. BC-PC and A-PC were transfused 57 and 41 times, respectively to 36 patients with chemotherapy- induced thrombocytopenia. PCs transfused within 2 days of donation were considered fresh, and those transfused within 3-5 days were considered stored. IVBT was determined before, as well as 10-30 min and 24 h after transfusion; CCI was determined 10-30 min and 24 h after transfusion. The median pretransfusion IVBT value was 486 s. It was measurable in 21 of 98 (21%) of the transfusions, i.e. below the cutoff limit of 486 s. Ten to 30 min after transfusion, the IVBT showed a measurable reduction in 90% of the transfusions with fresh BC-PCs, 92% of those with fresh A-PCs, 63% of those with stored BC-PCs and 79% of those with stored A-PCs. After 24 h, the corresponding values were 63% for fresh BC-PCs, 50% for fresh A-PCs, 26% for stored BC-PCs and 38% for stored A-PCs. The median value of CCI 10- 30 min after transfusion was 20 for fresh BC-PCs, 17 for fresh A-PCs, 16 for stored BC-PCs and 14 for stored A-PCs. The difference in IVBT between fresh and stored BC-PCs was significant (p = 0. 032), unlike that between fresh and stored A-PC. After 24 h the corresponding values were 7 for fresh BC-PCs, 4 for fresh A-PCs, 4 for stored BC-PCs and 3 for stored A-PCs. When all transfusions with fresh PCs (BC-PCs + A-PCs) were compared with all transfusions with stored PCs, a statistical difference was demonstrated in both CCI (p = 0.027) and IVBT (p = 0.043). Spearman’s rank correlation coefficient (rs) was -0.41 between CCI and IVBT 10-30 min after transfusion, and -0.55 between the posttransfusion plateled count and IVBT, indicating a relatively poor correlation between CCI and IVBT, and a slightly better correlation between platelet count and IVBT. In conclusion, BC-PCs showed a slightly higher CCI and a better response in IVBT than A-PCs. No statistical difference was demonstrated between BC-PCs and A-PCs transfused within 2 days after donation, with respect to function and recovery in vivo. BC-PCs stored for 3 days or more showed about the same CCI and IVBT as stored A-PC but significantly lower CCI and higher IVBT than fresh BC-PCs. This may indicate that the preparation and/or storage conditions were not optimal. IVBT seems to be a useful possibility to test the in vivo behavior of transfused platelets.

show abstract

Detection of Abnormal Platelet Functions with an in vitro Model of Primary Haemostasis

Cited by 32 publications

References 3 publications

Comparison of Hemorrhagic Effect of Heparin and Human Activated Protein C with Use of Thrombostat 4000

Comparison of Hemorrhagic Effect of Heparin and Human Activated Protein C with Use of Thrombostat 4000

Statin Potentiates Human Platelet eNOS Activity without Enhancing eNOS mRNA and Protein Levels

Evaluation of Platelet Function Using the in vitro Bleeding Time and Corrected Count Increment of Transfused Platelets

Contact Info

Product

Resources

About