thrombotic events in polycythemia vera patients may be related to increased oxidative stress

This study was designed to compare the oxidative stress parameters of patients with polycythemia vera [PV] to those of healthy volunteers and to investigate the probable relationship between vascular events and parameters of oxidative status such as total oxidative status [TOS], total antioxidant status, oxidative stress index [OSI] and malondialdehyde [MDA] in PV patients. Thirty-five PV patients [20 males and 15 females] and 20 healthy volunteers [11 males and 9 females] were enrolled. The oxidative status parameters of the patients were measured by spectrophotometric analyses at the time of diagnosis and at 6 months after treatment which consisted of phlebotomy and 100 mg/day acetyl salicylic acid with or without hydroxyurea for the high- and low-risk disease group, respectively. These parameters were compared both to healthy controls and to each other, in order to obtain the values before and after treatment. In addition, during diagnosis, the oxidative status parameters of patients with PV and a history of a vascular event were compared with those of patients with no history of a vascular event. The TOS, OSI and MDA values were significantly higher in the patients than in the control group at the time of diagnosis. At 6 months after phlebotomy and 100 mg/day acetyl salicylic acid therapy, the TOS, OSI and MDA values were significantly lower in the patients when compared to the pretreatment values. The TOS and OSI levels were notably higher in the patients with a vascular-event history than in those without this history. Oxidative stress parameters were increased in PV patients

Effect of early or delayed administration of warfarin with heparin on thrombosis in pulmonary thromboembolism

The aim of this study was to investigate the effect of early or delayed warfarin administration with unfrac-tionated heparin [UFH] on coagulation parameters in pulmonary thromboembolism [PTE]. This study was performed between November 2006 and July 2007. Thirty-three patients with PTE were sequentially slotted to early [n = 16] and delayed [n = 17] warfarin treatment groups. In the early group, both UFH infusion and warfarin were started simultaneously and in the delayed group, warfarin was added [1-3 days later] based on when partial thromboplastin time reached the therapeutic level with UFH. The proteins C and S, D-dimer, hematocrit levels, and platelet counts for all patients were studied prior to treatment and 6.24, and 48 h after warfarin treatment. In order to determine the overall effect of early and delayed warfarin treatment on clot formation, a thromboelastogram was performed simultaneously. In both groups, a similar chronological decrease in protein C levels reaching maximum at 24 h with warfarin treatment was observed. However, intragroup or intergroup decreases in protein S levels were not different. On thromboelastogram, INTEM and EXTEM clotting times were significantly prolonged chronologically, but this prolongation was not different between groups. The suppressor effect of warfarin on proteins C and S in the early period of double anticoagulant treatment did not appear to aggravate the risk of thrombosis in patients with PTE in whom warfarin was started simultaneously with UFH