scholarly journals Validation of the relationship between coagulopathy and localization of hydroxyethyl starch on the vascular endothelium in a rat hemodilution model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryu Azumaguchi ◽  
Yasuyuki Tokinaga ◽  
Satoshi Kazuma ◽  
Motonobu Kimizuka ◽  
Kosuke Hamada ◽  
...  
Keyword(s):  
Hydroxyethyl Starch ◽  
Shear Viscosity ◽  
Formation Rate ◽  
Physiological Saline ◽  
Coagulation Factors ◽  
High Shear ◽  
Fibrin Gel ◽  
Isolated Aorta ◽  
Blood Coagulability ◽  
Von Willebrand

AbstractVarious anticoagulant properties have been associated with hydroxyethyl starch (HES). However, the mechanism remains unclear and it has not been fully considered whether these properties are beyond the dilutional effect itself. The aim of this study was to reproduce the coagulopathy induced by HES and to test the hypothesis that the coagulopathy is caused by endothelial or glycocalyx damage due to localization of HES on the endothelium, which is caused by the high shear viscosity of dilutional blood. Using a rat model, we compared blood coagulability measured by Sonoclot, levels of endothelial and glycocalyx damage markers and coagulation factors, and blood shear viscosity when hemodilution was performed with physiological saline (PS), 6% HES 130/0.4 in PS, and 10% HES 200/0.5 in PS. We also evaluated the localization rates of fluorescently labeled HES on endothelium in the isolated aorta. HES decreased the fibrin gel formation rate more than did PS. HES was shown to cover the endothelium, possibly due to its high shear viscosity, and this mechanism potentially acted to protect, rather than damage, the endothelium and glycocalyx. However, this covering effect may be the cause of coagulopathy due to inhibition of von Willebrand factor secretion from the endothelium.

scholarly journals Validation of the Relationship Between Coagulopathy and Localization of Hydroxyethyl Starch on the Vascular Endothelium in a Rat Hemodilution Model

2021 ◽  
Author(s):  
Ryu Azumaguchi ◽  
Yasuyuki Tokinaga ◽  
Satoshi Kazuma ◽  
Motonobu Kimizuka ◽  
Kosuke Hamada ◽  
...  
Keyword(s):  
Hydroxyethyl Starch ◽  
Von Willebrand Factor ◽  
Shear Viscosity ◽  
Formation Rate ◽  
Coagulation Factor ◽  
Coagulation Factors ◽  
High Shear ◽  
Membrane Glycoproteins ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract BackgroundVarious anticoagulant properties have been associated with hydroxyethyl starch (HES), including coagulation disorders measured by point-of-care devices, decreases in von Willebrand factor and coagulation factor VIII, and inhibition of the interactions between platelet-membrane glycoproteins and of coagulation factors by coating of platelets. However, the mechanism for these properties remains unclear. The aim of this study was to test the hypothesis that coagulopathy induced by HES is caused by endothelial or glycocalyx damage as a result of localization of HES on the endothelium, due to the high shear viscosity of blood, using a rat model.MethodsWe compared blood coagulability measured by Sonoclot®, levels of endothelial and glycocalyx damage markers and coagulation factors, and blood shear viscosity when hemodilution was performed with physiological saline (PS), 6% HES 130/0.4 in PS (HES130) and 10% HES 200/0.5 in PS (HES200). To precisely evaluate the basic mechanism of coagulopathy induced by HES, we performed hemodilution with an emphasis on dilutional equality by taking into consideration the intravascular residual rates of the infusion preparations. We also evaluated the localization rates of fluorescently labeled HES on endothelium in the isolated aorta. Statistical analyses were performed by one-way ANOVA followed by Tukey’s test or Kruskal–Wallis test, and then Dunn’s test for multiple comparisons.ResultsSonoclot® measurements revealed that HES130 and HES200 decreased the fibrin gel formation rate to a greater extent than PS, and HES200 decreased the rate more than HES130. Similarly, HES130 and HES200 decreased von Willebrand factor levels to a greater extent than PS. HES130 and HES200 had a more protective effect than PS, with no evidence of damage to the endothelium or glycocalyx. Shear viscosity was variable between all pairs, and was lowest for PS and highest for HES200. HES130 and HES200 demonstrated comparable degrees of localization on the endothelium.ConclusionsHES was shown to cover the endothelium, possibly due to its high shear viscosity, and this mechanism potentially acted to protect the endothelium and glycocalyx. However, this covering effect may be the cause of coagulopathy due to inhibition of von Willebrand factor secretion from the endothelium.

Transient Ischemic Attack in a Hemophilia Patient with Severe Preeclampsia after Preoperative Administration of Tranexamic Acid and Factor VIII Replacement for Cesarean Section

2021 ◽  
Vol 9 (2) ◽  
Author(s):  
D’Onofrio JD ◽  
◽  
Hoffman CR ◽  
Goldberg SF ◽  
◽  
...  
Keyword(s):  
Tranexamic Acid ◽  
Transient Ischemic Attack ◽  
Hemophilia A ◽  
Coagulation Factors ◽  
Background Information ◽  
Preoperative Administration ◽  
Increased Risk ◽  
Pharmacologic Prophylaxis ◽  
Ischemic Attack ◽  
Von Willebrand

Hemophilia A in females accounts for few cases due to hemophilia A and B having X-linked recessive inheritance patterns. Hemostatic changes in pregnancy include an increase in coagulation factors and von Willebrand activity, placing hemophilia patients at an increased risk for Postpartum Hemorrhage (PPH). General recommendations include considering pharmacologic prophylaxis, including tranexamic acid and factor replacement when necessary. The ultimate goal is to prevent uncontrolled bleeding during vaginal or operative delivery. Benefits of prophylactic therapies must be weighed with relevant risk profiles of each intervention. We present a case where a parturient with hemophilia prophylactically treated with TXA and FVIII experienced a transient ischemic attack. We discuss the background information known regarding tranexamic acid and factor replacement, and the subsequent recommendations for their use in this patient population. We consider recommendations to expand the multidisciplinary team incorporated in the assessment and planning for the peripartum care of such a patient.

scholarly journals Platelet von Willebrand factor: evidence for its involvement in platelet adhesion to collagen

Blood ◽  
1987 ◽  
Vol 70 (4) ◽  
pp. 1214-1217
Author(s):  
E Fressinaud ◽  
D Baruch ◽  
C Rothschild ◽  
HR Baumgartner ◽  
D Meyer
Keyword(s):  
Shear Rate ◽  
Von Willebrand Factor ◽  
Platelet Adhesion ◽  
Von Willebrand Disease ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Von Willebrand ◽  
Willebrand Factor

Although it is well established that plasma von Willebrand Factor (vWF) is essential to platelet adhesion to subendothelium at high shear rates, the role of platelet vWF is less clear. We studied the respective role of both plasma and platelet vWF in mediating platelet adhesion to fibrillar collagen in a parallel-plate perfusion chamber. Reconstituted blood containing RBCs, various mixtures of labeled washed platelets and plasma from controls or five patients with severe von Willebrand disease (vWD), was perfused through the chamber for five minutes at a shear rate of 1,600 s-1. Platelet-collagen interactions were estimated by counting the radioactivity in deposited platelets and by quantitative morphometry. When the perfusate consisted of normal platelets suspended in normal plasma, platelet deposition on the collagen was 24.7 +/- 3.6 X 10(6)/cm2 (mean +/- SEM, n = 6). Significantly less deposition (16 +/- 2.3) was observed when vWD platelets were substituted for normal platelets. In mixtures containing vWD plasma, significantly greater deposition (9 +/- 2.2) was obtained with normal than with vWD platelets (1 +/- 0.4) demonstrating a role for platelet vWF in mediating the deposition of platelets on collagen. Morphometric analysis confirmed these data. Our findings indicate that platelet, as well as plasma, vWF mediates platelet-collagen interactions at a high shear rate.

scholarly journals Assessment Mixing and Compaction Temperatures for Modified HMA Using Superpave High Shear Viscosity Methods

2018 ◽  
Vol 21 (4) ◽  
pp. 516-522 ◽  
Author(s):  
Alaa Hussein Abed ◽  
Ali Hwaidi Nasser
Keyword(s):  
Shear Viscosity ◽  
Asphalt Mixture ◽  
High Shear ◽  
Compaction Temperature ◽  
Modified Asphalt ◽  
Performance Grade ◽  
Modified Binders ◽  
Different Temperatures ◽  
Marshall Stability

The objective of this study is determining the mixing and compaction temperature of the modified asphalt mixture. Results of binder tests showed that the addition of 3% SBS  to control asphalt (PG 64-16) would achieve the desired performance level (PG 76-16) a performance grade that fits our climate with traffic loads. When using 5% SBS the performance grade of binder increased three grades (PG 82-16) and when increasing SBS content to 8% the performance grade increased four grades (PG 88-16). At shear rate of 500 (s-1), the modified asphalt viscosity can be obtained at different temperatures and the viscosity temperature curve can be achieved. As a result, the mixing and compaction temperature of modified asphalt can be determined to reach 0.17 ± 0.02 Pa.s and 0.28 ± 0.03 Pa.s for mixing and compaction, respectively. It is noted that SBS modified reached a viscosity of 3 Pa.s when 8 % additive. Additive contents above these values may not be suitable for good workability and pump ability according to Superpave specifications. While addition of 5% SBS with control asphalt, more than 3.7times at 135°C Increase the viscosity. Marshall Stability test indicated that the strength for the SBS specimens increases as compared to the conventional specimens. An increase of about 39%, 74%, 102%, was observed with 3%SBS 5%SBS 8%SBS modified binders, respectively. The Marshall test results for 8%SBS binders required compaction temperatures above 175°C need to keep up quality of HMA item while limiting natural effect amid development, these proposals are unsatisfactory Modified mixtures the 5% SBS modification was determined to be the maximum useful content. The Superpave method to estimate mixing and compaction temperatures show are not practical for use with modified binders. Also,  it is observed that good agreement values between the average Marshall compaction temperature and the High Shear Viscosity Method (HSRV) and   lower than Superpave methods Where the decline ranges from 15 ºC to 17 ºC.

Effect of recombinant von Willebrand factor reproducing type 2B or type 2M mutations on shear-induced platelet aggregation

Blood ◽  
2000 ◽  
Vol 95 (12) ◽  
pp. 3796-3803 ◽  
Author(s):  
Nadine Ajzenberg ◽  
Anne-Sophie Ribba ◽  
Ghassem Rastegar-Lari ◽  
Dominique Meyer ◽  
Dominique Baruch
Keyword(s):  
Platelet Aggregation ◽  
Von Willebrand Factor ◽  
Von Willebrand Disease ◽  
High Shear ◽  
Shear Rates ◽  
High Shear Rates ◽  
Consistent Increase ◽  
A1 Domain ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The aim was to better understand the function of von Willebrand factor (vWF) A1 domain in shear-induced platelet aggregation (SIPA), at low (200) and high shear rate (4000 seconds-1) generated by a Couette viscometer. We report on 9 fully multimerized recombinant vWFs (rvWFs) expressing type 2M or type 2B von Willebrand disease (vWD) mutations, characterized respectively by a decreased or increased binding of vWF to GPIb in the presence of ristocetin. We expressed 4 type 2M (-G561A, -E596K, -R611H, and -I662F) and 5 type 2B (rvWF-M540MM, -V551F, -V553M, -R578Q, and -L697V). SIPA was strongly impaired in all type 2M rvWFs at 200 and 4000 seconds-1. Decreased aggregation was correlated with ristocetin binding to platelets. In contrast, a distinct effect of botrocetin was observed, since type 2M rvWFs (-G561A, -E596K, and -I662F) were able to bind to platelets to the same extent as wild type rvWF (rvWF-WT). Interestingly, SIPA at 200 and 4000 seconds-1 confirmed the gain-of-function phenotype of the 5 type 2B rvWFs. Our data indicated a consistent increase of SIPA at both low and high shear rates, reaching 95% of total platelets, whereas SIPA did not exceed 40% in the presence of rvWF-WT. Aggregation was completely inhibited by monoclonal antibody 6D1 directed to GPIb, underlining the importance of vWF-GPIb interaction in type 2B rvWF. Impaired SIPA of type 2M rvWF could account for the hemorrhagic syndrome observed in type 2M vWD. Increased SIPA of type 2B rvWF could be responsible for unstable aggregates and explain the fluctuant thrombocytopenia of type 2B vWD.

scholarly journals Direct radioimmune detection in human plasma of the association between factor VIII procoagulant protein and von Willebrand factor, and the interaction of von Willebrand factor-bound procoagulant VIII with platelets

Blood ◽  
1983 ◽  
Vol 61 (6) ◽  
pp. 1163-1173 ◽  
Author(s):  
JL Moake ◽  
MJ Weinstein ◽  
JH Troll ◽  
LE Chute ◽  
NM Colannino
Keyword(s):  
Factor Viii ◽  
Human Plasma ◽  
Von Willebrand Factor ◽  
Sodium Dodecylsulfate ◽  
Coagulation Factors ◽  
Cysteine Protease Inhibitors ◽  
Proteolytic Activation ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract The predominant procoagulant factor VIII (VIII:C) form in normal human plasma containing various combinations of anticoagulants and serine/cysteine protease inhibitors is a protein with mol wt 2.6 +/- 0.2 X 10(5). This protein can be detected by 125I-anti-VIII:C Fab binding and gel electrophoresis in the presence and absence of sodium dodecylsulfate (SDS) and is distinct from the subunit of factor VIII/von Willebrand factor (VIII:vWF) multimers. No larger VIII:C form is present in plasma from patients with severe congenital deficiencies of each of the coagulation factors, other than VIII:C. The mol wt approximately 2.6 X 10(5) VIII:C form is, therefore, likely to be the in vivo procoagulant form of VIII:C, rather than a partially proteolyzed, partially activated derivative of a larger precursor. About 60% of this procoagulant mol wt approximately 2.6 X 10(5) VIII:C form in plasma is present in noncovalent complexes with larger VIII:vWF multimers, which attach reversibly to platelet surfaces in the presence of ristocetin. This VIII:vWF-bound protein of mol wt approximately 2.6 X 10(5) may be the plasma procoagulant form of VIII:C which, after proteolytic activation, accelerates the IXa-mediated cleavage and activation of X postulated to occur on platelet surfaces.

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