Journal of thrombosis and haemostasis : JTH
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J. Thromb. Haemost. · Mar 2005
Review Comparative StudyPrimary and secondary prophylaxis of venous thromboembolism with low-molecular-weight heparins: prolonged thromboprophylaxis, an alternative to vitamin K antagonists.
Low-molecular-weight heparins (LMWHs) are used widely in the treatment and prevention of venous thromboembolism (VTE). The LMWHs dalteparin and enoxaparin reduce the rate of VTE by at least 50% if administered for 4-5 weeks following major orthopedic surgery, compared with in-hospital prophylaxis for 7-15 days. Meta-analyses have confirmed that the size of the reduction is similar for both clinical and asymptomatic VTE. ⋯ However, clinical trial data have confirmed that the LMWH dalteparin, when administered for 6 months, is significantly more effective than VKA in preventing recurrence, cutting the rate of VTE by 52% without increasing the risk of bleeding. A new and intriguing area of interest is whether LMWH can enhance survival in patients with cancer. Preliminary data suggest that a biological effect of LMWH may act to prolong survival in patients with cancer.
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J. Thromb. Haemost. · Mar 2005
Platelets adhered to endothelial cell-bound ultra-large von Willebrand factor strings support leukocyte tethering and rolling under high shear stress.
Leukocyte rolling on vascular endothelium is mediated by an interaction between P-selectin expressed on endothelial cells and P-selectin glycoprotein ligand-1 on leukocytes. This interaction reduces the velocity of leukocyte movements to allow subsequent firm adhesion and transmigration. However, the interaction has so far been observed only under low venous shear stress and cannot explain the accumulation of monocytes in atherosclerotic plaques found in arteries, where shear stress is much higher. ⋯ We also found that leukocytes tethered to and rolled on these platelet-decorated ULVWF strings, but not directly on endothelial cells, under high shear stresses of 20 and 40 dyn/cm(2) in a P-selectin dependent manner. These results suggest that the endothelial cell-bound ULVWF provide an ideal matrix to aggregate platelets and recruit leukocytes to endothelial cells under high shear stress. The observed phenomenon delineates a mechanism for leukocytes to be tethered to arterial endothelial cells under high shear, providing a potential link between inflammation and thrombosis.
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J. Thromb. Haemost. · Jan 2005
Multicenter StudyAccuracy of single-detector spiral CT in the diagnosis of pulmonary embolism: a prospective multicenter cohort study of consecutive patients with abnormal perfusion scintigraphy.
Spiral computed tomography (CT) has emerged as a potentially conclusive diagnostic test to exclude pulmonary embolism (PE) in patients with non-high probability scintigraphy and is already widely used-sometimes as the sole primary diagnostic test in the diagnosis of suspected PE. Its true sensitivity and specificity has, however, not been evaluated previously in a large cohort of consecutive patients. ⋯ The overall sensitivity of spiral CT for PE is too low to endorse its use as the sole test to exclude PE. This holds true even if one limits the discussion to patients with larger PE in segmental or larger pulmonary artery branches. We conclude that, in patients with clinically suspected PE and an abnormal perfusion scintigraphy, single-slice detector spiral CT is not sensitive enough to be used as the sole test to exclude PE.