Arterial and venous thrombosis are interrelated disorders at the interplay of platelets and fibrin. Arterial thrombi are platelet-rich and occur at sites vulnerable to atherosclerotic plaque rupture where blood shear rates are high; on the contrary, venous thrombi occur in association with slow blood flow and shear rates. These differences may underlie why anti-platelet agents are more effectiv...

THE significance of the fibrinogen content of the blood in the clotting mechanism has received little consideration except for the effects of obvious hypofibrinogenemia in hemorrhagic states. Hyperfibrinogenemia occurs in many conditions that are associated with thrombotic complications and may be a factor in their formation. The purpose of the present study has been to compare the response of ...

A central tenet of fibrinolysis is that tissue plasminogen activator-dependent (t-PA- dependent) conversion of plasminogen to active plasmin requires the presence of the cofactor/substrate fibrin. However, previous in vitro studies have suggested that the endothelial cell surface protein annexin II can stimulate t-PA-mediated plasminogen activation in the complete absence of fibrin. Here, homoz...

This book describes the fibrinolytic enzymes of microbial origin that are able to dissolve endogenous thrombi in vivo. The fibrinolytic enzyme streptokinase for example, is produced by b-hemolytic streptococci and exerts its enzyme action indirectly by activating plasminogen. On the other hand, staphylokinase is produced by Staphylococcus aureus by stoichiometric complexation with plasmin(ogen)...

Shiga toxin 1 (Stx-1) and Stx-2 produced by enterohemorrhagic Escherichia coli cause the diarrhea-associated hemolytic uremic syndrome (HUS). This type of HUS is characterized by obstruction of the glomeruli and renal microvasculature by platelet-fibrin thrombi, acute renal failure, thrombocytopenia, microvascular hemolytic anemia, and plasma levels of von Willebrand factor (VWF)-cleaving prote...

OBJECTIVE Placental factors and hypoxemia are the keys to intrauterine growth restriction (IUGR) and stillbirth. The aim of the study is to analyze histological changes in placentas of IUGR fetuses in pregnancies with no apparent etiologic factor and unexplained intrauterine fetal deaths. MATERIAL AND METHODS A total of 110 placentas were collected; 26 placentas of IUGR fetuses with no appare...

BACKGROUND Flavone-8-acetic acid (FAA; [Flavonoid]), an adjuvant antitumor drug, inhibits ristocetin-induced aggregation of human platelets. The effect of FAA on platelet-dependent thrombosis was studied in vivo in the porcine carotid artery after deep arterial injury by balloon angioplasty. METHODS AND RESULTS (111)In-labeled autologous platelet and (125)I-labeled porcine fibrin(ogen) deposi...

OBJECTIVE Wegener's granulomatosis (WG) can cause endothelial cell damage and thromboembolic events. Nevertheless, there have been few studies on the pulmonary microcirculation--small and medium-sized pulmonary arteries (SMSPA)--in patients with WG. The objective of this study was to quantify fibrin thrombi in the SMSPA of patients with WG. METHODS We analyzed 24 SMSPA samples collected from ...

OBJECTIVE Bone marrow-derived progenitor cells play a role in vascular regeneration. However, their homing to areas of vascular injury is poorly understood. One of the earliest responses to an injury is the activation of coagulation and platelets. In this study we assessed the role of hemostatic components in the recruitment of CD34+ cells to sites of injury. METHODS AND RESULTS Using an ex v...

BACKGROUND Dysfunction of haemodialysis catheters is most commonly due to a narrowing of the catheter lumen and/or formation of a fibrin sheath around the catheter tip. Reported methods for restoring patency of the catheter lumen include passage of a J-tipped guide wire, passage of a biopsy brush through the catheter, or infusion of a thrombolytic agent into the catheter. While these methods ar...