Biomedical subjects

Marta Frigerio

Publications and source records attributed to Marta Frigerio.

3 recordsLinked to original sources

PubMed2005

Increased prothrombotic state lasting as long as one month after on-pump and off-pump coronary surgery.

OBJECTIVE: This study investigated whether the activation of coagulation, fibrinolysis, and endothelium occurring during the first postoperative month after on-pump coronary artery bypass surgery differs from that after off-pump coronary artery bypass grafting. METHODS: Thirty-five patients candidates to coronary surgery were randomized to undergo on-pump (n = 18) or off-pump (n = 17) coronary artery bypass grafting. Blood samples were collected before the intervention and to 1 month after surgery. RESULTS: Prothrombin fragment F1.2, thrombin-antithrombin complex, and D-dimer increased after surgery and were persistently higher than preoperative values as late as 30 postoperative days in both on- and off-pump groups; higher levels of these variables were detected after on-pump surgery relative to off-pump surgery only at the time point after termination of cardiopulmonary bypass (fragment F1.2 and thrombin-antithrombin complex) or from bypass end to 8 postoperative days (D-dimer). Fibrinogen levels decreased after surgery and then increased in parallel in both groups to 8 days after surgery. The von Willebrand factor level increased postoperatively in both groups and returned to baseline 30 days after surgery; it was higher after on-pump surgery from bypass end to 8 postoperative days. Soluble vascular cell adhesion molecule 1 was increased significantly from baseline in both groups 30 days after surgery, with no difference between groups. CONCLUSION: Patients undergoing off-pump surgery showed protection against activation of coagulation and fibrinolysis and against endothelial injury only during the intraoperative period; this was followed by the development of a prothrombotic pattern comparable to that of patients undergoing on-pump surgery lasting at least as late as 30 days after surgery.

Blood Coagulation↗

PubMed2005

The role of tissue factor and P-selectin in the procoagulant response that occurs in the first month after on-pump and off-pump coronary artery bypass grafting.

BACKGROUND: It has been previously shown that a persistent (up to 1 month) prothrombotic status occurs after coronary bypass surgery performed both on pump and off pump. To assess the pathways involved in the occurrence of postoperative prothrombotic state, in this study we evaluated plasma, monocyte-bound, and platelet-bound tissue factor expression, as well as platelet and soluble P-selectin expression, up to 1 month after off-pump and on-pump coronary artery bypass grafting. METHODS: Thirty patient candidates for coronary surgery were randomized to undergo off-pump coronary artery bypass grafting (n = 15) or on-pump coronary artery bypass grafting (n = 15). Blood samples were collected before the intervention, after protamine administration, and 4, 8, and 30 days after surgical intervention. RESULTS: Plasma tissue factor levels were significantly higher than baseline both in the on-pump coronary artery bypass grafting group (from protamine administration up to 4 postoperative days) and in the off-pump coronary artery bypass grafting group (at 4 postoperative days), with no differences between groups. Basal and lipopolysaccharide-stimulated monocyte tissue factor expression, as well as basal and adenosine diphosphate-stimulated platelet tissue factor expression, did not show significant variations over time and were similar in the on-pump and off-pump coronary artery bypass grafting groups throughout the course of the study. Platelet expression of P-selectin, both basal and after adenosine diphosphate stimulation, did not significantly change over time and was not different in the on-pump and off-pump coronary artery bypass grafting groups. Soluble P-selectin levels in plasma were significantly higher in patients receiving on-pump coronary artery bypass grafting only at the time point after protamine administration, whereas this variable behaved similarly in the on-pump and off-pump coronary artery bypass grafting groups for the whole postoperative period. CONCLUSIONS: The postoperative tissue factor and P-selectin expression did not differ between the on-pump and off-pump coronary artery bypass grafting groups. The distinct increase of plasma tissue factor occurring after both surgical procedures might represent a mechanism that might explain, in part, the early postoperative prothrombotic state occurring after on-pump and off-pump coronary artery bypass grafting.

Aged↗

PubMed2003

Platelet activation induces cell-surface immunoreactive tissue factor expression, which is modulated differently by antiplatelet drugs.

OBJECTIVE: Tissue factor (TF) is the main activator of the coagulation cascade occurring in physiologic and pathologic conditions. Recent data suggest that human platelets might contain TF that is possibly derived from leukocytes. In this study, we investigated whether intraplatelet TF can be exposed on the membrane by platelet agonists. The modulation of this process by antiplatelet drugs has been evaluated as well. METHODS AND RESULTS: Flow cytometric analysis of unstimulated platelets showed a small amount of membrane-associated immunoreactive TF (irTF) in whole blood, platelet-rich plasma, and washed platelets isolated from healthy subjects. ADP, thrombin receptor-activating peptide, and epinephrine significantly increased functionally active, membrane-associated irTF. ADP induced irTF exposure in a concentration- and time-dependent fashion. Agonist-induced irTF expression was completely inhibited by iloprost but not by aspirin. Interestingly, glycoprotein IIb/IIIa antagonists did not inhibit but rather potentiated the stimulatory effect of ADP on platelet irTF expression. Real-time polymerase chain reaction experiments showed detectable amounts of TF mRNA in unstimulated platelets. CONCLUSIONS: These findings indicate that platelet agonists and antiplatelet drugs might modulate platelet-associated irTF expression. Regulated TF expression establishes the potential for a previously unrecognized role for platelets in sustaining thrombus formation and growth via coagulation-mediated mechanisms.

Antigens, Surface↗