摘要:

Cancer and increased age are risk factors for coagulation activation. Patients with advanced prostate cancer, which usually presents in the seventh to eighth decade of life, are likely to be at increased risk for thrombosis. We report results of a controlled study of changes in specific and sensitive markers of coagulation activation in patients with prostate cancer. Complete blood count, prothrombin time, partial thromboplastin time, prothrombin fragment 1 + 2 (F1 + 2), thrombin–antithrombin complex (TAT) and quantitative D-dimers (DD) were measured in 30 patients of advanced prostate cancer (androgen ablated), in 30 newly diagnosed localized prostate cancer patients, in 30 healthy age-matched volunteers, and in 20 healthy young volunteers. Plasma F1 + 2 (P< 0.05) and DD (P< 0.05), but not TAT, were significantly elevated in healthy elderly males (mean age, 77 years) when compared with healthy young volunteers (mean age, 35 years). F1 + 2, TAT and DD were significantly elevated in advanced prostate cancer when compared with healthy age-matched controls (P< 0.001). In conclusion, advanced prostate cancer patients have significantly increased levels of sensitive markers of coagulation activation compared with healthy age-matched controls. This data can be used to plan studies to determine the risk of clinically significant coagulopathy and the role of primary prophylaxis in patients with advanced prostate cancer.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Transmittance waveforms are the optical data generated during clot formation on photo-optical coagulation analyzers and are used to define specific events of the clotting reactions. Thus, a prothrombin time (PT) or an activated partial thromboplastin time (aPTT) can be divided into a pre-coagulation phase, a coagulation phase, and a post-coagulation phase. These phases are further characterized by parameters that define the timing, the rate, the ‘slope', and the magnitude of the signal change of the reactions. We investigated the transmittance waveform parameters obtained during PT and aPTT of patients with antiphospholipid antibodies (APLA) who were or were not taking warfarin, normal donors, and non-APLA patients taking warfarin. An abnormal deflection in the pre-coagulation phase of the PT (calledslope 1) was observed in 61.5% of the patients with APLA, in contrast to 5.9% of non-APLA patients taking warfarin (P= 0.0015). The presence of an abnormal PTslope 1was reagent specific and was inversely correlated with the anticardiolipin antibody immunoglobulin G (IgG) level, which suggests that the abnormal PTslope 1may reflect interactions between patient IgG and components from the thromboplastin, possibly phospholipids. The abnormal PTslope 1values may be of diagnostic utility in the identification of patients with antiphospholipid syndromes.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The purpose of the present study was to assess the effect of magnesium and manganese ions on tissue factor (TF)-induced coagulation and the possible role of factor IX therein. When magnesium chloride or manganese chloride were added in low concentrations to normal human plasma, the human (recombinant) TF-induced coagulation time was shortened. At higher concentrations, magnesium and manganese prolonged the TF-induced coagulation time. Maximum shortening of the coagulation time was obtained at a concentration of 0.5 mmol/l Mn or 2 mmol/l Mg in plasma. Shortening of the TF-induced coagulation time by magnesium and manganese was also observed in factor IX-deficient plasma. A comparison was made between TF preparations from human, rabbit, and bovine brain. The accelerating effect of magnesium was greater with human than with rabbit brain TF. Using bovine brain TF, the clotting time was not shortened by magnesium. Activated factor X-induced coagulation of normal plasma was not accelerated by magnesium. From these experiments, it is inferred that activation of factor X by factor VII–TF can be accelerated by magnesium and manganese ions independently of factor IX.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

An elevated plasma level of factor VII is a risk factor for coronary artery disease. We investigated environmental, familial, and genetic influences on factor VII activity in 508 family members of 87 probands who underwent elective coronary arteriography. Maximum likelihood methods were used to fit several genetic and non-genetic models of inheritance to these data to determine whether an unobserved Mendelian major gene could explain the familial distribution of factor VII. Factor VII activities were adjusted for age, gender, body mass index, smoking, alcohol consumption, menopause status, and triglycerides prior to this segregation analysis (this model accounted for 33.5% of the total variation). Adjusted factor VII activities showed strong familial aggregation with an estimated parent–offspring correlation of 0.34, sibling correlation of 0.36 and a smaller spouse correlation of 0.16. Regressive models were used to test genetic and non-genetic models in these 87 families. Mendelian single-locus models with either two or three underlying genotypic distributions of factor VII activities were best supported by these data. Essentially, these Mendelian models suggest most individuals come from a low distribution (mean, 116%), with a few individuals homozygous for a high allele drawn from a distribution with a mean of 166%. Future linkage studies may be worthwhile to further clarify the mechanisms controlling factor VII activity.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

The present study was designed to test the hypothesis that markers of a hypercoagulable state predict subsequent cardiovascular events in hypertensives. To do this, we performed a prospective follow-up analysis of 178 patients (86 male; mean age, 54 years (standard deviation, 15); mean blood pressure, 188/103 mmHg) recruited from a hypertension clinic in a city-centre teaching hospital serving a multi-ethnic population. The main outcome measures were clinical and echocardiographic details, and laboratory markers of thrombosis and haemostasis (fibrinogen, fibrin D-dimer, plasminogen activator inhibitor, soluble P-selectin, von Willebrand factor, and viscosity) that were measured at baseline. After a mean follow-up of 45 months (interquartile range, 37–54), 30 subjects experienced one of a number of endpoints that included death or adverse cardiovascular event. These patients were older (P< 0.001) and had significantly higher plasma von Willebrand factor (P= 0.015) and fibrin D-dimer levels (P= 0.005) compared with those 148 who were free of endpoints at follow-up. There were no statistically significant differences in mean blood pressure, other measured parameters, and the left ventricular mass index between the groups. Using univariate ‘time to event’ analysis, only high (⩾ median) baseline systolic blood pressures were associated with a shortened event-free survival (log rank test,P= 0.0078). We conclude that hypertensive patients who experienced a new cardiovascular event were much older and had more endothelial dysfunction and thrombogenesis than those who were free of complications. However, only high baseline systolic blood pressures were associated with a shortened event-free survival.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Monocyte tissue factor expression was evaluated in 67 patients with hepatosplenic Schistosomiasis. They were classified as Child A (n= 15), Child B (n= 15), Child C (n= 12) and Bleeders (n= 10), in addition to 15 healthy controls. Mononuclear cells were culturedin vitrowith and without lipopolysaccharide (LPS) to assess monocyte tissue factor (TF) antigen (Ag) and activity (Act) in cell lysate, in addition to measurement of prothrombin fragment 1 + 2 (F1 + 2) as a marker ofin vivothrombin generation. A significant increase in monocyte TF Ag and TF Act was noted in all stages of the disease compared with the control group, with marked accentuation during an acute attack of variceal bleeding. This enhanced monocyte expression was noted before the addition of LPS and became more obvious with addition of LPS. An increasing level of F1 + 2was similarly noted. These findings constitute further evidence for an existing prothrombotic state in hepatosplenic Schistosomiasis, and also that monocytes are closely implicated in the haemostatic diathesis characterizing the disease.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Patients in the intensive care unit (ICU) are at risk for the development of vitamin K deficiency. We sought to determine the frequency of this deficiency by performing a prospective cohort study in which patients were screened for vitamin K deficiency on ICU admission and every other day thereafter. Vitamin K deficiency was diagnosed by a functional coagulation factor II to Echis factor II ratio < 0.70. Activity of the coagulation cascade was measured by D-dimer. In total, 40 patients were enrolled into the study. Seven of the patients had ratios < 0.70 on the day of admission to the ICU, and three patients developed ratios < 0.70. Thus, 10 of 40 patients (25%; 95% confidence interval, 12–38%) had vitamin K deficiency. Two patients developed coagulopathy, as indicated by an International Normalized Ratio of more than 1.4. D-dimer levels were elevated in 86 of 111 samples. We conclude that vitamin K deficiency is common among critically ill patients, particularly on admission to the ICU. Our findings suggest that additional clinical research is warranted to determine whether vitamin K supplementation on admission to the ICU reduces the risk of ICU-acquired vitamin K deficiency and its attendant complications over the course of the ICU stay.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

We report on a 57-year-old woman with three episodes of ischemic strokes and hereditary hemorrhagic telangiectasia (HHT). Tests for inherited and acquired thrombophilia showed elevated anticardiolipin immunoglobulin (Ig)M antibodies (on three separate occasions), anti-prothrombin IgG antibodies, and the heterozygous form of factor V Leiden. This is the first case of HHT, a primary antiphospholipid syndrome, combined with factor V Leiden. No detectable arteriovenous malformation was found and ischemic episodes, documented by computer tomography, were related to the presence of antiphospholipid antibodies and possibly the carriership of factor V Leiden mutation. Since aspirin provoked severe nasal hemorrhages, treatment with ticlopidine was initiated after the third stroke. Over an 18-month follow-up, ischemic episodes were absent and we regarded oral anticoagulation as unjustifiable.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Retinal artery occlusion is rare in young adults, and may be associated with hereditary thrombophilia. We present a 19-year-old male who was evaluated for central retinal artery occlusion and found to be homozygous for the factor V Leiden mutation and heterozygous for the prothrombin G20210A mutation. Anterior chamber paracenthesis resulted in dramatic improvement, but recurring loss of vision necessitated repeated paracenthesis and the addition of aspirin to standard anticoagulation treatment. The literature concerning hereditary thrombophilia and retinal artery occlusion is reviewed, and the synergistic effect of multiple risk factors is emphasized. Screening for hereditary thrombophilia should be considered for young people presenting with unexplained retinal artery occlusion.

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID

摘要:

Prothrombin time-derived measurement of fibrinogen (PTd) has already been described. Activated partial thromboplastin time-derived measurement of fibrinogen (aPTTd) has not yet been clearly defined. Using an MDA®II coagulometer (Organon Teknika, Durham, North Carolina, USA), we have therefore compared fibrinogen levels determined with Clauss, PTd, and aPTTd assays and an enzyme immunoassay (EIA) in 172 samples. Of these, 47 were from pre-operative controls, 18 from patients with liver disease, 28 from patients with hyperfibrinogenaemia, 33 from patients treated with vitamin K antagonists, 22 from patients treated with unfractionated heparin and 24 from haemophilic patients. Within the normal range, interassay and intra-assay variations were comparable. For control samples, PTd, aPTTd and Clauss assays were well correlated, without any systematic error. EIA was also correlated but values were slightly higher (mean of difference = 0.24). Pathological samples showed an overestimation of fibrinogen when using PTd measurements in patients treated with vitamin K antagonists, as well as when using aPTTd measurements in patients presenting with factor VIII and factor IX deficiencies. These results indicate that, despite expected financial savings, aPTTd fibrinogen measurements should not be used without restriction. PTd and aPTTd fibrinogen determinations are provided without any additional cost. Their comparison with Clauss fibrinogen results may constitute a validation tool or have additional diagnostic utility (e.g. identifying polymerization abnormalities in case of dissimilar results).

ISSN:0957-5235    

出版商:OVID    

年代:2002

数据来源: OVID