fibrin and Retinal-Vein-Occlusion

To evaluate (ex vivo) the characteristic of fibrin clotting in patients with retinal vein occlusion.. Fifty nine patients with a history of retinal vein occlusion were enrolled in the study. The diagnosis of retinal vein occlusion was based on the typical fundus appearance, supplemented by digital photography, fluorescein angiography, and optical coherence tomography. The control group consisted of 59 subjects matched for age, sex, body mass index, medications, and cardiovascular risk factors. The ex vivo fibrin clots obtained from citrate plasma samples from all patients were used for the measurement of clot permeation, expressed as the permeability coefficient, Ks (Darcy constant). The turbidity of fibrin clot formation, reflected by the "lag phase" of the turbidity curve and maximum absorbance at plateau (deltaAb(max)), tissue-plasminogen activator (t-PA) - induced fibrinolysis characterized by maximum rates of increase in D-dimer levels (D-Drate) and maximum D-dimer concentrations (D-Dmax) were evaluated. The time required for 50% decrease in maximum clot absorption (t50%) was chosen as an additional marker of clot susceptibility to fibrinolysis.. Patients with retinal vein occlusion were characterized by the unfavourable plasma fibrin clot properties. Clot permeability was 30% lower, as compared to the controls (p < 0.0001), the "lag phase" was 11% shorter (p < 0.0001) indicating faster fibrin formation, and the deltaAb(max) was 19% higher (p < 0.0001), indicating thicker fibrin fibers. The D-Dmax indicating thrombotic mass available for fibrinolytic agents was 22% higher in the RVO group (p < 0.0001) and the t50% was 29% longer (p < 0.0001) compared with controls. Only the D-Drate was similar in both groups (p = 0.223). The differences remained statistically significant after adjustment for fibrinogen, glucose, and platelet count.. The results indicate that in patients with retinal vein occlusion, less porous plasma fibrin clots composed of thicker fibrils with the reduced permeability and susceptibility to lysis are found, as compared to controls. Plasma fibrinogen and C-reactive protein levels are recognized as the most important modulators of fibrin function. retinal vein occlusion, pathogenesis.

Topics: Adolescent; Adult; Aged; C-Reactive Protein; Female; Fibrin; Fibrinogen; Fibrinolysis; Humans; Male; Middle Aged; Retinal Vein Occlusion; Young Adult

Branch Retinal Vein Occlusion (BRVO) is the second chronic branch retinal vascular disease that causes abnormal vision loss after acute branch retinal disease in type 2 diabetes. There is no scientific conclusion about its specific pathogenic mechanism at present. Most clinical scholars generally support the theory that the partial human anatomical structure and various systemic risk psychological factors cause insufficient oxygen supply and hemostasis in the local branch retinal arteries. The research results of this article aim to reconstruct a non-nanocell-targeted thrombolytic drug delivery system without modification of rtPA without polyethylene glycol-methyl polycaprolactone and to re-evaluate its thrombus targeting and dissolution. The effect and safety of thrombus provide a new strategy for realizing combined treatment of thrombus. It is a study on the targeting of rtPA-NP to thrombus and its thrombolytic properties. HPLC method was used to detect the binding of fibrin clot prepared in vitro with coumarin-6 labeled NP and rtPA-NP; immunofluorescence technique was used to observe the location of nanomedicine and fibrin clot in branch retinal vein occlusion model Condition. The rtPA-NP drug delivery system constructed in this study not only retains the activity of rtPA and good thrombus targeting but also significantly prolongs its half-life and simplifies the way of administration. The therapeutic efficiency of rtPA-NP thrombus targeted administration on branch retinal vein occlusion reached 85.64%. The successful construction of the rtPA-NP thrombus targeted drug delivery system provides a new way for thrombosis treatment and lays the foundation for the future combination of anticoagulants and vascular protection drugs to achieve the combined treatment of thrombosis and the development of safe and efficient thrombolytic drugs.

Topics: Diabetes Mellitus, Type 2; Fibrin; Fibrinolytic Agents; Humans; Nanoparticles; Recombinant Proteins; Retinal Vein Occlusion; Thrombolytic Therapy; Thrombosis; Tissue Plasminogen Activator

Topics: C-Reactive Protein; Coronary Artery Disease; Female; Fenofibrate; Fibrin; Fibrinolysis; Heptanoic Acids; Homocysteine; Humans; Hypersensitivity, Immediate; Laser Coagulation; Lipoprotein(a); Male; Pyrroles; Retinal Vein; Retinal Vein Occlusion; Simvastatin; Tetrahydroisoquinolines; Thrombosis; Venous Thromboembolism; Venous Thrombosis

To describe a novel missense mutation in the antithrombin gene associated with antithrombin deficiency type I in a 40-year-old man with retinal vein occlusion.. Investigational case report.. Ophthalmoscopy of the right eye showed hemicentral retinal vein occlusion. The patient's medical history was negative for glaucoma or cardiovascular risk factors. Screening for thrombophilic disorders revealed antithrombin deficiency type I. Based on a genetic analysis, a novel missense mutation of a transition of guanosine to cytosine at nucleotide position 9840 was detected, predicting the replacement of aspartic acid by histidine encoded by codon 366 (D366H) in exon 5.. Selective screening may be helpful in identifying patients with retinal vein occlusion with thrombophilic defects. When ordering laboratory tests in patients with retinal vein occlusion, antithrombin deficiency type I should be considered in the differential diagnosis.. Our results contribute to a better understanding of the molecular bases of antithrombin deficiency, adding a novel entry for the molecular defects causing antithrombin deficiency type I. Moreover, the identification of this thrombophilic disorder in retinal vein occlusion may be relevant to the issue of the initiation and duration of oral anticoagulant therapy.

Topics: Adult; DNA Mutational Analysis; Fibrin; Humans; Immunoelectrophoresis; Male; Mutation, Missense; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Retinal Vein Occlusion; Sequence Analysis, DNA