ABSTRACT
OBJECTIVE: The main objective was to study the relationships of the molecular defects in 38 dysfibrinogens with their fibrin networks. METHODS AND RESULTS: Scanning electron microscopic analyses revealed that all the fibrins formed under the same conditions had networks composed of either normal thickness fibers or thin fibers, accompanied by a variety of alterations in the network structure and characteristics. We classified these fibrin networks into five classes, designated normal, less-ordered, porous A, porous B and lace-like networks. The dysfibrinogens with defects in fibrinopeptide A release or the E:D binding sites formed normal or less-ordered networks, while those with defects in the D:D association formed porous A networks composed of many tapered terminating fibers, despite having fibers of normal width, and containing many pores or spaces. The porous B and lace-like networks were composed of highly branched thin fibers because of defects in the lateral association among protofibrils, and the major difference between them was the porosity of the porous B networks. All the porous B networks were easily damaged by mechanical stress, whereas the lace-like networks retained high resistance to such stress, indicating that the network strength was not dependent on the fiber width, but on the porosity that led to fragility of the network. CONCLUSION: Impairment of the D:D association is the major disturbing factor that leads to the formation of porous fibrin networks. The porosity may be introduced by severe impairment of the D:D association, as well as the lateral association, as has often been observed by extra glycosylation or defects in Ca2+ binding.
Subject(s)
Afibrinogenemia/blood , Fibrin/chemistry , Fibrin/ultrastructure , Fibrinogen/chemistry , Fibrinogens, Abnormal/genetics , Blood Coagulation , Fibrin/classification , Fibrinogens, Abnormal/classification , Fibrinogens, Abnormal/ultrastructure , Heterozygote , Homozygote , Humans , Microscopy, Electron, Scanning , Time FactorsABSTRACT
Esta revisión hace referencia a la epidemiología de los estados trombofílicos más importantes, con todas las dificultades para establecer su verdadera prevalencia, la cual se halla influenciada por diversos factores: demográficos, diagnósticos, poblacionales, entre otros. De los pacientes con antecedentes trombóticos recurrentes y/o historia familiar, sólo un 10 por ciento obedece a una trombofilia, existiendo alrededor de un 25 por ciento que posiblemente la presente, pero en donde su etiología no ha podido ser determinada con los métodos hoy disponibles. Las alteraciones fibrinolíticas continúan siendo objeto de discusión, con respecto a la relevancia clínica y a su carácter hereditario (AU)
Subject(s)
Humans , Thrombosis/epidemiology , Thrombosis/classification , Thrombosis/physiopathology , Antithrombin III/deficiency , Protein C/deficiency , Fibrinogens, Abnormal/classification , Fibrinogens, Abnormal/physiology , Thrombophlebitis/etiology , Thrombophlebitis/physiopathology , Plasminogen/deficiency , Plasminogen Inactivators/deficiency , Plasminogen Activators/deficiency , Homocystinuria/physiopathologyABSTRACT
Esta revisión hace referencia a la epidemiología de los estados trombofílicos más importantes, con todas las dificultades para establecer su verdadera prevalencia, la cual se halla influenciada por diversos factores: demográficos, diagnósticos, poblacionales, entre otros. De los pacientes con antecedentes trombóticos recurrentes y/o historia familiar, sólo un 10 por ciento obedece a una trombofilia, existiendo alrededor de un 25 por ciento que posiblemente la presente, pero en donde su etiología no ha podido ser determinada con los métodos hoy disponibles. Las alteraciones fibrinolíticas continúan siendo objeto de discusión, con respecto a la relevancia clínica y a su carácter hereditario
