vitamin-k-semiquinone-radical and Blood-Platelet-Disorders

Our understanding of haemostatic mechanisms has increased in the last decades. This knowledge at the cellular and molecular levels has helped us to appreciate the complexity of haemostatic mechanisms and their disturbance in various disorders. The advance in techniques to measure early activation of coagulation and platelets opens hope of treating acquired bleeding disorders e.g., disseminated intravascular coagulation before the full blown picture. More study needs to be done to define what constitutes normal haemostasis in newborns. The better understanding of control mechanisms of haemostasis will help us in diagnosis and treatment.

Topics: Antithrombin III; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelet Disorders; Blood Platelets; Blood Vessels; Child; Factor VIII; Fibrinolysis; Glycoproteins; Hemophilia A; Hemostasis; Humans; Infant, Newborn; Platelet Storage Pool Deficiency; Prostaglandins; Protein C; Vitamin K; von Willebrand Diseases; von Willebrand Factor

Topics: Abruptio Placentae; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelet Disorders; Blood Transfusion; Disseminated Intravascular Coagulation; Embolism, Amniotic Fluid; Factor XIII Deficiency; Female; Fetal Death; Fetal Diseases; Fibrin; Fibrinogen; Fibrinolysis; Hemophilia A; Humans; Liver Diseases; Pre-Eclampsia; Pregnancy; Pregnancy Complications, Hematologic; Sepsis; Uterine Hemorrhage; Vitamin K

Topics: Blood Coagulation Disorders; Blood Coagulation Factors; Blood Flow Velocity; Blood Platelet Disorders; Blood Transfusion; Cholestasis; Chronic Disease; Diagnosis, Differential; Factor V; Fibrinolysis; Hemorrhage; Hemostasis; Humans; Liver; Liver Diseases; Platelet Adhesiveness; Prognosis; Prothrombin Time; Vitamin K

Recurrent bleeding can complicate the treatment of thrombosis patients with vitamin K antagonists (VKA), even at a well-regulated level of anticoagulation. In this proof-of-principle study, we investigated whether alterations in platelet function or von Willebrand factor (vWf) contribute to a bleeding phenotype in these patients.. In this case-control study 33 well-regulated patients without bleeding events (controls) and 33 patients with recurrent bleeding (cases) were retrospectively included. Thrombin generation and vWf were determined in plasma. Platelet function was assessed by light transmission aggregometry and flow cytometry using a validated panel of agonists.. Thrombin generation was similarly reduced in controls and cases, in comparison to normal plasma. Plasma vWf level was above the normal range in 85% of controls and 67% of the cases. vWf activity was similarly increased in all patients in comparison to healthy volunteers. Platelet aggregation was in the normal range for almost all patients irrespective of the type of agonist. However, in response to a low collagen dose, platelets from 21% of controls and 27% of cases showed diminished responses. Agonist-induced secretion of alpha- and dense-granules or integrin αIIbβ3 activation were affected in platelets from neither controls nor cases.. Recurrent bleeding in well-controlled patients on VKA therapy is not explained by anti-hemostatic changes in platelet or vWf function.

Topics: Aged; Blood Platelet Disorders; Blood Platelets; Case-Control Studies; Female; Hemorrhage; Humans; Integrins; Male; Platelet Aggregation; Recurrence; Thrombin; Thrombosis; Vitamin K; von Willebrand Factor

Topics: Antithrombins; Aspirin; Blood Coagulation Disorders; Blood Platelet Disorders; Hemorrhagic Disorders; Humans; Receptors, Cytoplasmic and Nuclear; Thrombocytopenia; Vitamin K

Topics: Blood Coagulation Tests; Blood Platelet Disorders; Blood Platelets; Blood Vessels; Hemostasis; Humans; Platelet Aggregation; Vitamin K

Topics: Animals; Ascorbic Acid; Ascorbic Acid Deficiency; Blood Coagulation Factors; Blood Platelet Disorders; Blood Platelets; Dicumarol; Factor VII; Glycine max; Hemorrhage; Hemostatics; Humans; Pedigree; Phospholipids; Plasma; Prothrombin; Prothrombin Time; Rabbits; Thrombocytopenia; Thromboplastin; Vitamin K; Vitamin K Deficiency

Topics: Blood Coagulation Disorders; Blood Coagulation Factors; Blood Coagulation Tests; Blood Platelet Disorders; Brain Damage, Chronic; Factor V; Factor VII; Female; Fibrinogen; Fibrinolysis; Germany, West; Humans; Infant, Newborn; Pregnancy; Pregnancy Complications; Prothrombin; Prothrombin Time; Retrospective Studies; Vitamin K; Vitamin K Deficiency Bleeding

Topics: Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelet Disorders; Consanguinity; Diagnosis, Differential; Factor XIII; Female; Hemorrhage; Humans; Infant, Newborn; Infant, Newborn, Diseases; Male; Umbilical Cord; Vitamin K; Vitamin K Deficiency Bleeding

Topics: Anticoagulants; Antithrombin III; Blood Coagulation; Blood Coagulation Disorders; Blood Coagulation Tests; Blood Platelet Disorders; Factor IX; Factor VII; Factor X; Fibrinogen; Hemostasis; Heparin; Humans; Prothrombin; Thrombelastography; Thrombin; Thromboplastin; Thrombosis; Vitamin K

Topics: Aging; Anticoagulants; Blood Coagulation Disorders; Blood Coagulation Factors; Blood Platelet Disorders; Blood Platelets; Blood Preservation; Blood Specimen Collection; Blood Transfusion; Exchange Transfusion, Whole Blood; Humans; Isoantibodies; Plasmapheresis; Thrombocythemia, Essential; Thrombocytopenia; Vitamin K

Topics: Anemia; Anemia, Macrocytic; Anemia, Megaloblastic; Blood Platelet Disorders; Factor VII Deficiency; Female; Humans; Hypoprothrombinemias; Pregnancy; Pregnancy Complications; Pregnancy Complications, Hematologic; Thrombocytopenia; Vitamin K