Assuntos
Doença de Fabry/complicações , Heterozigoto , Oclusão da Artéria Retiniana/etiologia , Adolescente , Adulto , Cegueira/diagnóstico , Doença de Fabry/enzimologia , Doença de Fabry/genética , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Oclusão da Artéria Retiniana/enzimologia , Oclusão da Artéria Retiniana/genética , Adulto Jovem , alfa-Galactosidase/metabolismoRESUMO
PURPOSE: An insertion/deletion (I/D) polymorphism of the gene for angiotensin-converting enzyme (ACE) is associated with higher ACE plasma levels and activity. This enzyme is known to play an important role in blood pressure regulation and the ACE I/D gene polymorphism has been suggested as a risk factor for atherosclerotic vascular diseases. The purpose of the present study was to investigate a hypothesized association between the ACE I/D polymorphism and retinal artery occlusion (RAO). METHODS: A total of 159 patients with RAO and 304 control subjects were enrolled in the present retrospective case-control study. ACE I/D genotypes were determined by polymerase chain reaction. RESULTS: Allelic frequencies and genotype distribution of the ACE I/D polymorphism did not significantly differ between patients and control subjects (ACE DD 25.8% versus 28.0%; p = 0.36). A logistic regression analysis predicted the presence of RAO by arterial hypertension and current smoking status, but not by ACE I/D genotypes. CONCLUSION: Our data suggest that the ACE I/D polymorphism is not a major risk factor for RAO.
Assuntos
Deleção de Genes , Mutagênese Insercional/genética , Peptidil Dipeptidase A/genética , Polimorfismo Genético , Oclusão da Artéria Retiniana/genética , Idoso , Estudos de Casos e Controles , DNA/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Hipertensão/genética , Masculino , Reação em Cadeia da Polimerase , Oclusão da Artéria Retiniana/enzimologia , Estudos Retrospectivos , Fatores de Risco , Fumar/genéticaRESUMO
PURPOSE: To analyze the potential cause of retinal arterial occlusion in a 9-year-old child. METHODS: Case report. Antithrombin III, protein C, free protein S, activated protein C resistance, and antiphospholipid antibodies in plasma were determined. Determination of factor V R506Q (Leiden mutation), thermolabile methylene tetrahydrofolate reductase by polymerase chain reaction, and restriction enzyme analysis were performed. RESULTS: The patient was found to be heterozygous for factor V R506Q (Leiden mutation) and homozygous for thermolabile methylene tetrahydrofolate reductase. CONCLUSION: Coexistence of two mild hereditary thrombophilic states may result in severe thrombotic manifestations in young people.
Assuntos
Fator V/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-NH/genética , Mutação Puntual/genética , Oclusão da Artéria Retiniana/genética , Criança , Ativação Enzimática , Feminino , Angiofluoresceinografia , Fundo de Olho , Heterozigoto , Humanos , Metilenotetra-Hidrofolato Redutase (NADPH2) , Reação em Cadeia da Polimerase , Proteína C/metabolismo , Oclusão da Artéria Retiniana/enzimologia , Oclusão da Artéria Retiniana/patologia , Transtornos da Visão/enzimologia , Transtornos da Visão/genética , Transtornos da Visão/patologiaRESUMO
PURPOSE: To describe a patient with peripheral retinal neovascularization and vascular occlusion associated with activated protein C resistance. METHODS: Case report. A 63-year-old woman was examined for acute loss of vision in both eyes. She was noted to have macular edema in both eyes as well as a macular branch vein occlusion in the right eye and a central retinal vein occlusion in the left eye. Peripheral retinal neovascularization was present in both eyes. RESULT: Extensive systemic evaluation disclosed a heterozygous state for the factor V Leiden indicating activated protein C resistance. CONCLUSION: Activated protein C resistance may be associated with peripheral retinal neovascularization.
Assuntos
Proteína C/metabolismo , Oclusão da Artéria Retiniana/enzimologia , Neovascularização Retiniana/enzimologia , Oclusão da Veia Retiniana/enzimologia , Ativação Enzimática , Fator V/genética , Feminino , Angiofluoresceinografia , Fundo de Olho , Humanos , Pessoa de Meia-Idade , Mutação Puntual/genética , Oclusão da Artéria Retiniana/genética , Neovascularização Retiniana/genética , Oclusão da Veia Retiniana/genéticaRESUMO
PURPOSE: Nitric oxide synthase (NOS) plays an essential role in neuronal function and is critical in the brain for normal and pathologic responses to glutamate. The role of NOS in the retina is less well understood. The retina provides an experimental system in which the intrinsic circuitry is well defined; retinal excitotoxic damage has been well characterized. METHODS: To determine whether neuronal NOS (nNOS) and endothelial NOS (eNOS) are critical in excitotoxic damage in the retina, nNOS- and eNOS-deficient mice were subjected to intravitreal injections of N-methyl-D-aspartate (NMDA) or to arterial occlusions. RESULTS: Retinal ganglion cells in the nNOS-deficient mouse were relatively resistant to NMDA and to arterial occlusion. In contrast, the damage in the eNOS-deficient mouse retina was not distinguishable from that in control animals. Preinjection with an NOS inhibitor was partially protective. CONCLUSIONS: The presence of nNOS is a prerequisite for the full expression of excitotoxicity in the retina; eNOS does not appear to play a significant role.
