Thromboembolic Risks with Concurrent Direct Oral Anticoagulants and Antiseizure Medications: A Population-Based Analysis.

Background And Objective: Drug-drug interactions between direct oral anticoagulants (DOAC) and antiseizure medications via the cytochrome P450 (CYP) or the P-glycoprotein (P-gp) systems may lead to under-anticoagulation. The clinical relevance of these interactions is unclear. We aimed to elucidate the risk of thromboembolism with concurrent DOAC and CYP/P-gp modulating antiseizure medications.

Thrombotic complications of neonates and children with congenital nephrotic syndrome.

Congenital nephrotic syndrome (CNS) refers to a disease presenting with massive proteinuria in association with hypoalbuminemia, hyperlipidemia, and edema at birth or within the first three months of life. In the past, most children with CNS had extremely poor prognosis and succumbed to various complications, usually within the first 6 months. Recent advancements in protein supplementation and nutritional support, renal replacement therapy and renal transplantation in infancy, render these patients to have much better outcomes.

Reversal of new, factor-specific oral anticoagulants by rFVIIa, prothrombin complex concentrate and activated prothrombin complex concentrate: a review of animal and human studies.

Introduction: Recombinant activated factor VII (rFVIIa), prothrombin complex concentrate (PCC) and activated PCC (aPCC) are three non-specific haemostatic agents sometimes employed to reverse new, factor-specific oral anticoagulants.

Methods: We conducted a review in the literature to compare the abilities of rFVIIa, PCC and aPCC to reverse factor-specific anticoagulants. MEDLINE and EMBASE databases were searched up to Oct 2013.

Phenotype presentation for a novel mutation affecting a conserved cysteine residue in exon 63 of fibrillin-1 (Cys2633Arg).

Marfan syndrome is an autosomal dominant disease caused by mutations in the gene encoding for fibrillin-1 (FBN1). More than 1,000 FBN1 mutations have been identified, which may lead to multiple organ involvement, particularly of the ocular, skeletal, and cardiovascular systems. Mutations in exons 59-65 have been reported in the past to cause mild Marfan-like fibrillinopathies.

Zn2+ mediates high affinity binding of heparin to the αC domain of fibrinogen.

The nonspecific binding of heparin to plasma proteins compromises its anticoagulant activity by reducing the amount of heparin available to bind antithrombin. In addition, interaction of heparin with fibrin promotes formation of a ternary heparin-thrombin-fibrin complex that protects fibrin-bound thrombin from inhibition by the heparin-antithrombin complex. Previous studies have shown that heparin binds the E domain of fibrinogen.

Covalently linking heparin to antithrombin enhances prothrombinase inhibition on activated platelets.

Factor (F)Xa within the prothrombinase complex is protected from inhibition by unfractionated heparin (UFH), enoxaparin and fondaparinux. We have developed a covalent antithrombin-heparin complex (ATH) with enhanced anticoagulant activity. We have also demonstrated that ATH is superior at inhibiting coagulation factors when assembled on artificial surfaces.

Selective D-dimer testing for diagnosis of a first suspected episode of deep venous thrombosis: a randomized trial.

Background: D-Dimer testing is sensitive but not specific for diagnosing deep venous thrombosis (DVT). Changing the use of testing and the threshold level for a positive test result on the basis of risk for DVT might improve the tradeoff between sensitivity and specificity and reduce the need for testing.

Objective: To determine whether using a selective D-dimer testing strategy based on clinical pretest probability (C-PTP) for DVT is safe and reduces diagnostic testing compared with using a single D-dimer threshold for all patients.

Inhibition of the prothrombinase complex on red blood cells by heparin and covalent antithrombin-heparin complex.

The role of red blood cells (RBCs) in coagulation is not well understood. Overt exposure of phosphatidylserine on surfaces of RBCs provide docking sites for formation of the prothrombinase complex, which further aids in amplification of coagulation leading to subsequent thrombosis. No studies to date have evaluated heparin inhibition of the RBC-prothrombinase system.

By increasing the affinity of heparin for fibrin, Zn(2+) promotes the formation of a ternary heparin-thrombin-fibrin complex that protects thrombin from inhibition by antithrombin.

Heparin binds fibrin and, by bridging thrombin onto fibrin, promotes the formation of a ternary heparin-thrombin-fibrin complex that protects thrombin from inhibition by antithrombin. Because thrombin binds γ(A)/γ'-fibrin, a variant with an extended γ-chain, with higher affinity than the bulk γ(A)/γ(A)-fibrin, γ(A)/γ'-fibrin affords bound thrombin more protection from inhibition by antithrombin-heparin. We examined the effect of Zn(2+) on heparin-thrombin-fibrin complex formation because Zn(2+) modulates heparin-protein interactions.

Carotid artery dissections: thrombosis of the false lumen.

Carotid artery dissections are the second leading cause of stroke in young adults. The hemostatic response to a dissection involves exposure of the subendothelium to the intravascular environment. Platelet activation/aggregation superimposed by secondary coagulation cascade activity attempts to heal the injury.