system
Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, RESULTS. Meshes: Aged, Blood Coagulation, Case-Control Studies, Circular Dichroism, Female, Fibrinogen, Fibrinolysis, Humans, Male, Microscopy, Electron, Transmission, Microscopy, Interference, Middle Aged, Myocardial Infarction, Oxidation-Reduction, Oxidative Stress, Percutaneous Coronary Intervention, Platelet Aggregation Inhibitors, Protein Carbonylation, Protein Structure, Secondary, Structure-Activity Relationship, Time Factors.
user
Is oxidative modification of fibrinogen associated with altered function and structure in the subacute phase of myocardial infarction? Context: Among plasma proteins, fibrinogen represents a major target of oxidative modifications. In patients with post-acute myocardial infarction (6 months after the acute event), fibrinogen oxidation-induced carbonyls and fibrinogen function were estimated using in vitro and ex vivo approaches. Fibrinogen structural features and clot architecture were also explored. In 39 patients with post-acute myocardial infarction and 28 age-, sex-, and risk factor-matched controls, oxidative stress markers (in plasma and in purified fibrinogen fractions), thrombin-catalyzed fibrin polymerization, and plasmin-induced fibrin lysis were estimated. Circular dichroism spectra of purified fibrinogen extracts, electron microscopy, and differential interference contrast microscopy analyses of fibrin clots were also performed. Marked signs of oxidative stress in plasma (P<0.01 versus controls) and, correspondingly, an increased extent of fibrinogen carbonylation (3.5-fold over control values; P<0.01 versus controls) were observed in patients. Furthermore, fibrinogen fractions purified from patients exhibited significantly reduced clotting ability and decreased susceptibility to plasmin-induced lysis (P<0.01 versus controls). Alterations in fibrinogen secondary structure, as suggested by circular dichroism spectroscopy, and in fibrin clot architecture, as analyzed by electron and differential interference contrast microscopy, were also identified.
assistant
Here, we report for the first time that patients with post-acute myocardial infarction present with an overall imbalance in redox status and marked fibrinogen carbonylation associated with altered fibrinogen function, thus suggesting a role for carbonylation as a direct mechanism of fibrinogen function. The observed features occur along with modifications in protein structure and in clot architecture. Final Decision: yes