Atorvastatin reduces thrombin generation and expression of tissue factor, P-selectin and GPIIIa on platelet-derived microparticles in patients with peripheral arterial occlusive disease.

We investigated the effects of statin treatment on platelet-derived microparticles (PMPs) and thrombin generation in atherothrombotic disease. Nineteen patients with peripheral arterial occlusive disease were randomised to eight weeks of treatment with atorvastatin or placebo in a cross-over fashion. Expression of GPIIIa (CD61), P-selectin (CD62P), tissue factor (TF, CD142) and phosphatidylserine (PS; annexin-V or lactadherin binding) was assessed on PMPs.

A multicolor flow cytometric assay for measurement of platelet-derived microparticles.

Introduction: Flow cytometry (FCM) is the most commonly used method for detection of platelet-derived microparticles (PDMPs), but it is poorly standardized and mainly used for "bedside" analyses in fresh samples. If PDMPs could be analyzed in previously frozen samples it would increase the usefulness of the method. However, cell membrane fragments from contaminating cells created during freezing/thawing may cause artifacts and disturb measurements.

A global assay of haemostasis which uses recombinant tissue factor and tissue-type plasminogen activator to measure the rate of fibrin formation and fibrin degradation in plasma.

The global assay of Overall Haemostasis Potential we previously described has been refined. The coagulation cascade in platelet-poor plasma is triggered by adding a minimal dose of recombinant tissue factor together with purified phospholipids and calcium; fibrinolysis is initiated by adding recombinant tissue type-plasminogen activator in a concentration similar to what can be obtained during thrombolysis. Numerical differentials of optical densities reflecting rates of fibrin formation and degradation are calculated by a new software, and the Coagulation Profile (Cp) and the Fibrinolysis Profile (Fp) are determined.

NXY-059 does not affect bleeding time in healthy volunteers: a randomized, double-blind, placebo-controlled, 3-period crossover phase I study.

NXY-059 is a novel free radical-trapping neuroprotectant that reduces infarct size and preserves brain function in animal models of acute ischemic stroke. It is the first neuroprotectant to demonstrate a reduction in global disability in a phase III clinical trial, as measured by the modified Rankin Scale. Any effect of NXY-059 on hemostasis may be important when treating stroke patients.

Flow cytometric technique for determination of prostasomal quantity, size and expression of CD10, CD13, CD26 and CD59 in human seminal plasma.

Summary Prostasomes are prostate-derived organelles in seminal plasma exhibiting pluripotent properties to facilitate the fertilization process. Seminal prostasome concentration, size distribution and expression of the prostasomal surface antigens CD10, CD13, CD26 and CD59 were examined by flow cytometry. The study group consisted of 79 men with involuntary infertility.

Enhanced Fcgamma receptor I, alphaMbeta2 integrin receptor expression by monocytes and neutrophils in rheumatoid arthritis: interaction with platelets.

Objective: To investigate platelet and leukocyte activation and interaction in patients with rheumatoid arthritis (RA) and the effect of methotrexate (MTX) or anti-tumor necrosis factor-a (TNF-a) treatment on these variables.

Methods: Four-color flow cytometry analysis was performed for quantitative measurement of platelet (P-selectin, PAC-1) and leukocyte (CD11b, CD64) activation markers and estimation of percentage of leukocyte-platelet complexes in whole blood in 20 patients with RA before and after 6 weeks of therapy and in 20 controls. In addition, measures of soluble P-selectin (sP-selectin), beta-thromboglobulin, fibrinogen, prothrombin fragment 1+2, D-dimer, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), interleukin 6 (IL-6), and TNF-a and tender and swollen joint counts were carried out.

INR calibration of Owren-type prothrombin time based on the relationship between PT% and INR utilizing normal plasma samples.

Prothrombin time (PT) is clinically important and is used to monitor oral anticoagulant therapy. To obtain PT results in international normalized ratio (INR), the current standardization procedure is complex and involves reference reagents. The PT of diluted plasma samples can be determined with a combined thromboplastin (the Owren-type procedure), but not necessarily with a plain thromboplastin (the Quick-type procedure).

Local INR calibration of the Owren type prothrombin assay greatly improves the intra- and interlaboratory variation. A three-year follow-up from the Swedish national external quality assessment scheme.

In 1999, a simplified procedure for calibration of the Owren prothrombin time (Owren PT) assay was introduced by a working group of the organisation for national quality assurance in laboratory medicine in Sweden. The new protocol allowed local calibration by means of only two lyophilised national plasma calibrators and expression of results as an international normalized ratio (INR). This is our report of a three-year follow-up involving the analysis of data from all laboratories, in hospitals (n=88 in 2002) and primary health care units (n=246 in 2002) that perform the Owren PT assay in Sweden.

Are results of fibrinogen measurements transferable?

Fibrinogen concentration is routinely measured by several methods and the results may influence diagnostic and treatment strategies. It is therefore necessary that results are compatible and transferable between laboratories. In the present study, it is shown that commonly used immuno-nephelometric methods, a commercial variant of the Clauss clotting rate method, and the classical syneresis method, do not differ significantly using patient material, in the interval 2-12 g/l.

[Less variation in laboratory results after the introduction of INR. Differences between hospital laboratories and laboratories within primary health care are levelled out].

In 1999 a new and simplified procedure for calibration of the Owren prothrombin time (Owren PT) assay was introduced in Sweden by the national external quality assessment scheme (Equalis). The new protocol allowed local calibration by means of lyophilised national plasma calibrators and expression of results as an international normalised ratio (INR). A two-year follow-up involving analysis of data from all laboratories that have returned results to Equalis is reported.

Retained fibrinolytic response and no coagulation activation after acute physical exercise in middle-aged women with previous myocardial infarction.

Sudden physical exertion is associated with an increased risk of acute myocardial infarction (MI) and sudden cardiac death. In addition, activation of the coagulation cascade and/or reduced fibrinolytic capacity after physical exercise has been reported in patients with cardiovascular disease. We investigated the haemostatic responses to an acute submaximal physical exercise in middle-aged women with a history of MI compared with healthy, age-matched controls.

Correlation between soluble markers of endothelial dysfunction in patients with renal failure.

Aim: Damage to the endothelium is an important component of atherosclerosis. It has been suggested to be quantified by measuring plasma markers, such as von Willebrand factor and thrombomodulin and soluble adhesion molecules. We hypothesized there may exist a correlation between the plasma levels of von Willebrand factor and thrombomodulin as markers of endothelial cell dysfunction and the serum concentrations of soluble adhesion molecules and monocyte chemoattractant protein-1 (MCP-1) in patients with renal insufficiency, and in patients on peritoneal dialysis or hemodialysis since these three groups of kidney patients are highly prone to develop cardiovascular diseases.

The presence of heparin-platelet factor 4 antibodies as a marker of hypercoagulability during hemodialysis.

We have assessed the prevalence of heparin-platelet factor 4 antibodies in a group of 100 patients on chronic intermittent hemodialysis with repeated exposure to heparin in order to establish the clinical significance of an immunological response to heparin. Heparin-induced platelet reactivity was studied in a subgroup of 86 patients. Routine laboratory parameters such as plasma C-reactive protein, albumin and immunoglobulins were included.