eral biến chứng động mạch, chảy máu, giảm bạch cầu trung tính, giảm tiểu cầu, hoặc ngưng thuốc sớm vì một sự kiện bất lợi không do tim. Thiết bị đầu cuối này xảy ra ở 4,6% bệnh nhân trong nhóm clopidogrel so với 9,1% những người được chỉ định để ticlopidine. | 216 Goldhaber Dietary intake methionine synthase Homocysteine methyltransferase betaine liver tetrahydrofolate X c e s s I Tetrahydrofolate J cps B6 i Cystathionine - r .-- y-cystathionase ị Cysteine Urinary excretion Auto-oxidised homocysteine highly reactive oxygen species Lipid peroxidation vascular matrix damage smooth muscle .cell proliferation I Vascular endothelial injury I impaired vasomotor I regulation I prothrombotic surface Atherogenesls Thrombogenesls Ị Figure 2 Homocysteine metabolism and possible mechanism of atherothrombotic disease. Reprinted with permission from Ref. 30. tients with newly diagnosed VTE I usually screen for factor V Leiden and the prothrombin gene mutation which are more common than other inherited thrombophilias 29 as well as acquired hyperhomocysteinemia Fig. 2 and anticardiolipin antibodies. Elevated levels of homocysteine are usually easily treated with folate 30 31 and the presence of anticardiolipin antibodies suggests the possible need for prolonged and intensive anticoagulation 32 33 . B. Cancer Data from the Danish National Registry of Patients were used to investigate the risk of a diagnosis of cancer following the detection of VTE not associated with Venous Thromboembolism 217 Figure 3 Cumulative probability of newly diagnosed cancer after a first VTE episode according to whether the VTE was idiopathic or nonidiopathic. Reprinted with permission from Ref. 35. surgery known cancer or pregnancy 34 . There was a 30 increased risk of a diagnosis of cancer among those with newly detected VTE. The risk was substantially elevated only during the first 6 months of follow-up and declined rapidly thereafter. Of those diagnosed with cancer within 1 year after the initial VTE hospitalization 40 had distant metastases at the time of the cancer diagnosis. The association between cancer and VTE was most pronounced for cancers of the pancreas ovary liver primary hepatic cancer and brain. In the Swedish Cancer Registry the risk of .