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1.
Free Radic Biol Med ; 40(10): 1869-73, 2006 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-16678024

RESUMO

Chronic venous stasis determines red blood cell extravasation and either dermal hemosiderin deposits or iron-laden phagocytes. Several authors have suspected that iron could play a role in the pathogenesis of venous leg ulcers. They hypothesized that local iron overload could generate free radicals or activate a proteolytic hyperactivity on the part of metalloproteinases (MMPs) or else down-regulate tissue inhibitors of MMPs. However, they were unable to explain why iron deposits, visible in the legs of patients with chronic venous disease (CVD), cause lesions in only some individuals, whereas in others they do not. We hypothesized that such individual differences could be genetically determined and investigated the role of the C282Y and H63D mutations of the HFE gene. C282Y mutation significantly increases the risk of ulcer in primary CVD more than six times (OR = 6.69; 1.45-30.8; p = 0.01). Patients carrying the H63D variant have an earlier age of ulcer onset, by almost 10 years (p > 0.004). The increased risk of skin lesion and the early age of onset of the disease in HFE carriers confirm in a clinical setting that intracellular iron deposits of mutated macrophages have less stability than those of the wild type. We hypothesize that the physiologic iron protective mechanisms are affected by the HFE mutations and should be investigated in all diseases characterized by the combination of iron overload and inflammation.


Assuntos
Antígenos de Histocompatibilidade Classe I/genética , Sobrecarga de Ferro/patologia , Proteínas de Membrana/genética , Úlcera Varicosa/genética , Feminino , Proteína da Hemocromatose , Humanos , Sobrecarga de Ferro/fisiopatologia , Masculino , Mutação , Prevalência , Úlcera Varicosa/epidemiologia , Úlcera Varicosa/fisiopatologia
2.
Transfus Med ; 21(4): 280-4, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21733006
3.
J Am Coll Cardiol ; 48(11): 2178-85, 2006 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17161242

RESUMO

OBJECTIVES: The purpose of this study was to evaluate the value of platelet reactivity (PR) in predicting the response to treatment and outcome in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention assisted by glycoprotein (GP) IIb/IIIa inhibition. BACKGROUND: There is limited prognostic information on the role of spontaneous or drug-modulated PR in STEMI patients. METHODS: The PR was measured with Platelet Function Analyzer (PFA)-100 and light transmission aggregometry (LTA) using adenosine diphosphate as agonist in 70 consecutive STEMI patients at entry (PR-T0), 10 min after GP IIb/IIIa bolus (PR-T1), and discharge (PR-T2) and in 30 stable angina (SA) patients (PR-SA). Complete platelet inhibition (CPI) was based on closure time >300 s by PFA-100 and percentage inhibition of platelet aggregation >95% by LTA. Clinical, electrocardiographic, and angiographic responses to treatment during 1-year follow-up were collected. RESULTS: According to both techniques, PR-T0 was higher than: 1) PR-T2 and PR-SA; 2) in those without CPI at T1; and 3) in patients with final Thrombolysis In Myocardial Infarction (TIMI) flow grade <3. The PR-T0 assessed with PFA-100 correlated with: 1) corrected TIMI frame count (r = -0.6, p < 0.001); 2) ST-segment resolution (r = 45, p < 0.001); and 3) creatine kinase-MB (r = -0.47, p < 0.001). At 1 year, patients with high PR-T0 showed an adjusted 5- to 11-fold increase in the risk of death, reinfarction, and target vessel revascularization (hazard ratio [HR] 11, 95% confidence interval [CI] 1.5 to 78 [p = 0.02] in PFA-100; HR 5.2, 95% CI 1.1 to 23 [p = 0.03] in LTA). CONCLUSIONS: The PR at entry affects response to GP IIb/IIIa inhibition, mechanical treatment, and long-term outcome in STEMI patients undergoing primary intervention.


Assuntos
Angioplastia Coronária com Balão , Plaquetas , Eletrocardiografia , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/terapia , Complexo Glicoproteico GPIIb-IIIa de Plaquetas/antagonistas & inibidores , Stents , Abciximab , Idoso , Anticorpos Monoclonais/uso terapêutico , Angiografia Coronária , Creatina Quinase Forma MB/sangue , Feminino , Humanos , Fragmentos Fab das Imunoglobulinas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Agregação Plaquetária , Valor Preditivo dos Testes , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Tempo , Tirofibana , Resultado do Tratamento , Troponina I/sangue , Tirosina/análogos & derivados , Tirosina/uso terapêutico
4.
Dermatol Surg ; 31(6): 644-9; discussion 649, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15996413

RESUMO

BACKGROUND: Severe chronic venous disease (CVD) is characterized by both dermal hemosiderin accumulation and matrix metalloproteinase (MMP) hyperactivation. The iron-driven pathway is one of the recognized mechanisms of MMP hyperactivation. OBJECTIVE: To investigate the potential consequences of leg hemosiderin deposits on both iron metabolism and activation of MMPs. METHODS: We contemporaneously assessed the following in the serum of the arm and ankle veins of 30 patients (C4-6) with CVD and 14 normal subjects: ferritin, transferrin, iron, percentage of transferrin iron binding capacity (%TIBC), and MMP-9. Optical microscopy examinations with Perls' staining of chronic wounds were also performed. RESULTS: Histology consistently revealed iron deposits. Serum ferritin, iron, and %TIBC were significantly increased in the legs affected by severe CVD compared with the arm of the same subjects or the controls. In addition, iron and %TIBC were significantly elevated in the legs of ulcer patients. The rate of activation of MMP-9 was significantly elevated in CVD. CONCLUSIONS: The increased iron deposition in legs affected by CVD seems to be more instable in ulcer patients, leading to iron release in the serum of the affected leg. Our data suggest the iron-driven pathway as a further mechanism for MMP hyperexpression leading to tissue lesion.


Assuntos
Ferro/sangue , Úlcera da Perna/sangue , Metaloproteinase 9 da Matriz/sangue , Doenças Vasculares/sangue , Doença Crônica , Feminino , Ferritinas/sangue , Haptoglobinas/análise , Humanos , Macrófagos/fisiologia , Masculino , Pessoa de Meia-Idade , Transferrina/análise , Doenças Vasculares/fisiopatologia
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