SciCombinator

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Journal: Thrombosis research

141

The diagnostic work-up for heparin induced thrombocytopenia (HIT) can take several days. Consequently patients may be speculatively switched onto replacement anticoagulant therapy before a diagnosis is confirmed. On-demand immunoassay diagnostic testing enables timely treatment decisions, based on test results.

Concepts: Medical terms, Diagnosis, Anticoagulant, Heparin, Thrombocytopenia, Immunoassay, Medical test, Heparin-induced thrombocytopenia

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Host cell lines used for recombinant protein expression differ in their ability to perform post-translational modifications (PTMs). The currently available recombinant human FVIII (rhFVIII) products are produced in mammalian, non-human cell lines. For rhFVIII, glycosylation and sulfation are vital for functionality and von Willebrand factor (VWF)-binding affinity. Here we present the characterisation of the PTMs of a novel, human cell line-derived recombinant human FVIII (human-cl rhFVIII). rhFVIII expression in a human cell line avoids expression of undesirable mammalian glycoforms like Galα1-3Galβ1-GlcNAc-R (α-Gal) and N-glycolylneuraminic acid (Neu5Gc), which constitute epitopes antigenic to humans.

Concepts: DNA, Cell, Human, Cell biology, Biotechnology, Posttranslational modification, Von Willebrand factor, Factor VIII

28

Idiopathic avascular necrosis (AVN) of bone causes significant morbidity in adults although the pathophysiology is unknown. The present treatment options include systemic biphosphonate therapy and local bone drilling decompression, ameliorating the healing process and their by render the weight bearing femur head less vulnerable to collapse. In the present study we demonstrate the involvement of heparanase in AVN and in the acceptable treatments.

Concepts: Inflammation, Present, Healing, Heart, Femur, Avascular necrosis, 2006 albums, Femur head

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INTRODUCTION: Warfarin treatment with a high time in therapeutic range (TTR) is correlated to fewer complications. The TTR in Sweden is generally high but varies partly depending on local expertise and traditions. A dosing algorithm could minimize variations and increase treatment quality. Here we evaluate the performance of a computerized dosing algorithm. MATERIALS AND METHODS: 53.779 warfarin treated patients from 125 centers using the Swedish national quality registry AuriculA. If certain criteria are met, the algorithm gives one of seven possible dose suggestions, which can be unchanged, decreased or increased weekly dose by 5, 10 or 15%. The outcome evaluated by the resulting INR value was compared between dose suggestions arising from the algorithm that were accepted and those that were manually changed. There were no randomization, and outcomes were retrospectively analyzed. RESULTS: Both the algorithm-based and the manually changed doses had worse outcome if only two instead of three previous INR values were available. The algorithm suggestions were superior to manual dosing regarding percent samples within the target range 2-3 (hit-rate) or deviation from INR 2.5 (mean error). Of the seven possible outcomes from the algorithm, six were significantly superior and one equal to the manually changed doses when three previous INR:s were present. CONCLUSIONS: The algorithm-based dosing suggestions show better outcome in most cases. This can make dosing of warfarin easier and more efficient. There are however cases where manual dosing fares better. Here the algorithm will be improved to further enhance its dosing performance in the future.

Concepts: Algorithm, Warfarin, Dose, Computer-aided design, Outcome, Equals sign, Prothrombin time, Manual transmission

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INTRODUCTION: Hyperfibrinolysis is observed during and immediately after major orthopedic surgery. The kinetics and duration of this phase should be defined to adjust the duration of antifibrinolytic treatment with tranexamic acid (TXA). OBJECTIVE: We aimed to quantify the duration of postoperative fibrinolysis and to assess the biological impact of TXA administration. MATERIALS AND METHODS: Fourteen patients undergoing total hip replacement (THR) and 10 patients undergoing total knee replacement (TKR) with tourniquet were included in an observational, prospective, single-center study. Among these patients, 7 THR patients and 5 TKR patients received TXA (15mg/kg IV intraoperatively, followed by continuous infusion of 15mg/kg/h until end of surgery, then every 4hours until 16±2hours after surgery). D-dimers, euglobulin lysis time (ELT), and thrombin generation time (TGT) were measured prior to surgery as well as 6, 18 and 24hours (H) after. RESULTS: No significant difference in ELT was observed between the groups. In contrast, D-dimers significantly increased postoperatively in patients not treated with TXA (p<0.001), while such an increase was prevented in patients receiving TXA, as measured at H0, H6, H18 and H24 after THR, and at H6 and H18 after TKR (p<0.001). No significant between-group change in TGT, was observed (peak thrombin and endogenous thrombin potential) all along the study. CONCLUSION: This study shows that fibrinolysis peaked 6hours after end of surgery and maintained about 18hours after surgery, as evidenced by an increase in D-dimers. When administered for up to 16±2hours after surgery, TXA reduced postoperative fibrinolysis.

Concepts: Hip replacement, Orthopedic surgery, Joint replacement, Knee replacement, Polyethylene, Antifibrinolytic, John Charnley

27

Apart from TTP, ADAMTS13 may be an important player in those conditions where Von Willebrand Factor and the Platelet Glycoprotein GP Ib axis have a part to play in the pathogenesis. This includes stroke, myocardial infarction, sepsis and inflammatory condition. This article reviews the literature in these conditions.

Concepts: Myocardial infarction, Atherosclerosis, Platelet, Von Willebrand factor, Von Willebrand disease, Aspirin, Thrombotic thrombocytopenic purpura, Heyde's syndrome

27

Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study.

Concepts: Pharmacology, Understanding, Effectiveness, Distribution, Pharmacokinetics, Factor VII

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The coagulation pattern and the determinants of portal vein thrombosis (PVT), both in patients with and without cirrhosis, are still largely unknown. The aim of this study was to evaluate whole blood thromboelastometry profile, performed by ROTEM®, of both cirrhotic and non-cirrhotic subjects with PVT. Two different groups were considered: i) 14 non-cirrhotic PVT patients, ii) 35 cirrhotic patients with PVT. Controls were sex- and age-matched healthy volunteers and cirrhotic subjects without PVT, respectively. ROTEM® assays (i.e. INTEM, EXTEM, NATEM, and FIBTEM) and traditional coagulative parameters (i.e. platelet count, PT/INR, aPTT, and fibrinogen) were performed on blood samples from each subject. There were no significant differences in ROTEM® profile, as for INTEM, EXTEM, and NATEM assays, and in traditional coagulative parameters, between PVT patients, both with and without cirrhosis, and control groups. Interestingly, Maximum Clot Firmness (MCF) in FIBTEM was significantly higher in non-cirrhotic PVT patients (19mm) than in healthy volunteers (11mm, p<0.05). The amplitude of MCF in FIBTEM revealed to be a useful tool to discriminate non-cirrhotic subjects with PVT from those without thrombotic events. Larger prospective studies are needed to evaluate the relevance of the association between the alterations of ROTEM® profiles and PVT in cirrhotic patients.

Concepts: Blood, Thrombosis, Coagulation, Platelet, Vein, Hepatic portal vein, Portal vein thrombosis, Portal venous system

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INTRODUCTION: The objective of this study was to compare wound and bleeding complications between women who received anticoagulation after cesarean delivery due to history of prior venous thromboembolic disease, arterial disease, or being a thrombophilia carrier with adverse pregnancy outcome, to women not receiving anticoagulation. METHODS: Women in the Duke Thrombosis Center Registry who underwent cesarean delivery during 2003-2011 and received postpartum anticoagulation (anticoagulation group, n=77), were compared with a subset of women who delivered during the same time period, but did not receive anticoagulation (no anticoagulation group, n=77). The no anticoagulation group comprised women who were matched to the anticoagulation group by age, body mass index, type of cesarean (no labor vs. labor), and date of delivery. Bleeding and wound complications were compared between the two groups. A multivariable logistic regression model was constructed to determine if anticoagulation was an independent predictor of wound complication. RESULTS: Women who received anticoagulation during pregnancy had a greater incidence of wound complications compared to those who did not (30% vs. 8%, p<0.001). Using multivariable logistic regression, while controlling for race, diabetes, chorioamnionitis, and aspirin use, anticoagulation predicted the development of any wound complication (OR 5.8, 95% CI 2.2, 17.6), but there were no differences in the mean estimated blood loss at delivery (782 vs. 778ml, p=0.91), change in postpartum hematocrit (5.4 vs. 5.2%, p=0.772), or percent of women receiving blood products (6.5 vs. 1.3%, p=0.209) between the two groups. CONCLUSIONS: Anticoagulation following cesarean delivery is associated with an increased risk of post-cesarean wound complications, but not other postpartum bleeding complications.

Concepts: Regression analysis, Childbirth, Blood, Thrombosis, Obstetrics, Body mass index, Vein, Caesarean section

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The present study aimed to compare characteristics related to selection of a P2Y12 antagonist, investigate initiation of therapy with new-generation drugs, and identify predictors of high on-treatment platelet reactivity (HTPR) in patients with acute coronary syndrome treated with stent percutaneous coronary intervention (PCI).

Concepts: Present, Cardiology, Percutaneous coronary intervention, Clopidogrel, Stent, Acute coronary syndrome