Pulmonary embolism and deep vein thrombosis-comorbidities and temporary provoking factors in a register-based study of 1.48 million people.

Background: Knowledge on differences in patients who present with deep vein thrombosis (DVT) and those with pulmonary embolism (PE) is incomplete.

Objective: To determine comorbidities and temporary provoking factors in patients with a first-time PE or DVT.

Methods: This was a nationwide Swedish registry-based, retrospective, case-control study including 298 172 patients with first-time venous thromboembolism (VTE) and 1 185 079 controls matched for age, sex, and county of residence, free of VTE at the time of matching.

Disturbed Laminar Blood Flow Causes Impaired Fibrinolysis and Endothelial Fibrin Deposition In Vivo.

Endothelial expression of tissue-type plasminogen activator (t-PA) is crucial for maintaining an adequate endogenous fibrinolysis. It is unknown how endothelial t-PA expression and fibrinolysis are affected by blood flow in vivo. In this study, we investigated the impact of different blood flow profiles on endothelial t-PA expression and fibrinolysis in the arterial vasculature.

Rapid and specific hypomethylation of enhancers in endothelial cells during adaptation to cell culturing.

Epigenetics, including DNA methylation, is one way for a cell to respond to the surrounding environment. Traditionally, DNA methylation has been perceived as a quite stable modification; however, lately, there have been reports of a more dynamic CpG methylation that can be affected by, for example, long-term culturing. We recently reported that methylation in the enhancer of the gene encoding the key fibrinolytic enzyme tissue-type plasminogen activator (t-PA) was rapidly erased during cell culturing.

Dependence of Proximal GC Boxes and Binding Transcription Factors in the Regulation of Basal and Valproic Acid-Induced Expression of t-PA.

Objective. Endothelial tissue-type plasminogen activator (t-PA) release is a pivotal response to protect the circulation from occluding thrombosis. We have shown that the t-PA gene is epigenetically regulated and greatly induced by the histone deacetylase (HDAC) inhibitor valproic acid (VPA).

Dynamic Enhancer Methylation--A Previously Unrecognized Switch for Tissue-Type Plasminogen Activator Expression.

Tissue-type plasminogen activator (t-PA), which is synthesized in the endothelial cells lining the blood vessel walls, is a key player in the fibrinolytic system protecting the circulation against occluding thrombus formation. Although classical gene regulation has been quite extensively studied in order to understand the mechanisms behind t-PA regulation, epigenetics, including DNA methylation, still is a largely unexplored field. The aim of this study was to establish the methylation pattern in the t-PA promoter and enhancer in non-cultured compared to cultured human umbilical vein endothelial cells (HUVECs), and to simultaneously examine the level of t-PA gene expression.

Histone deacetylase inhibition enhances tissue plasminogen activator release capacity in atherosclerotic man.

Unlabelled: The expression of the tissue plasminogen activator (t-PA) gene appears to be under epigenetic control and can be affected by histone deacetylation inhibition. The study aimed to test if histone deacetalyase inhibitor treatment lead to increased t-PA release or reduced exhaustion in t-PA release in response to stimulation, as well as change in plasminogen activator inhibitor-1 (PAI-1) in subjects with coronary disease. In this clinical study, 16 post-myocardial infarction subjects, the perfused forearm model was used with isoprenaline provocation during 20 minutes, to stimulate local t-PA release.

Profibrinolytic effect of the epigenetic modifier valproic acid in man.

Aims: The aim of the study was to test if pharmacological intervention by valproic acid (VPA) treatment can modulate the fibrinolytic system in man, by means of increased acute release capacity of tissue plasminogen activator (t-PA) as well as an altered t-PA/Plasminogen activator inhibitor -1 (PAI-1) balance. Recent data from in vitro research demonstrate that the fibrinolytic system is epigenetically regulated mainly by histone deacetylase (HDAC) inhibitors. HDAC inhibitors, including VPA markedly upregulate t-PA gene expression in vitro.

Histone deacetylase inhibitor treatment increases coronary t-PA release in a porcine ischemia model.

Background: The expression of the tissue plasminogen activator gene can be affected by histone deacetylation inhibition and thus appears to be under epigenetic control.

Objectives: The study aimed to test if in vivo pharmacological intervention by valproic acid treatment would lead to increase in tissue plasminogen activator release capacity.

Methods: In an anaesthetized pig model, a controlled transient coronary occlusion was used to stimulate coronary tissue plasminogen activator release in a valproic acid treated (one week) and a non-treated group.

Histone deacetylase inhibitors stimulate tissue-type plasminogen activator production in vascular endothelial cells.

A reduced capacity for acute tissue-type plasminogen activator (t-PA) release is likely to be associated with an impaired endogenous defense against intravascular thrombosis. Efficient approaches to pharmacologically restore a defective t-PA release have been lacking, but recent observations suggest that histone deacetylase inhibitors (HDACis) enhance t-PA production in vitro. HDACis have diverse chemical structures and different HDAC-enzyme sub-class targeting.

Role of histone acetylation in the stimulatory effect of valproic acid on vascular endothelial tissue-type plasminogen activator expression.

Aims: Stimulated release of tissue-type plasminogen activator (t-PA) is pivotal for an intravascular fibrinolytic response and protects the circulation from occluding thrombosis. Hence, an impaired t-PA production is associated with increased risk for atherothrombotic events. A pharmacological means to stimulate the production of this enzyme may thus be desirable.

Platelets retain high levels of active plasminogen activator inhibitor 1.

The vascular fibrinolytic system is crucial for spontaneous lysis of blood clots. Plasminogen activator inhibitor 1 (PAI-1), the principal inhibitor of the key fibrinolytic enzyme tissue-type plasminogen activator (tPA), is present in platelets at high concentrations. However, the majority of PAI-1 stored in platelets has been considered to be inactive.

The impaired fibrinolytic capacity in hypertension is unaffected by acute blood pressure lowering.

The endogenous fibrinolytic system and the ability of the endothelium to release tissue-plasminogen activator (t-PA) play a pivotal role to protect humans from atherothrombotic events. We have recently reported that the decreased capacity for t-PA release in hypertension is restored with chronic blood pressure lowering. Thus, we explored if acute blood pressure lowering has the same effect.

Hypothermia in cardiogenic shock reduces systemic t-PA release.

Therapeutic hypothermia has been found to improve hemodynamic and metabolic parameters in cardiogenic shock. Tissue plasminogen activator (t-PA) is a pro-thrombolytic enzyme, which also possesses pro-inflammatory properties. Interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) are pro-inflammatory cytokines; interleukin 10 (IL-10) and transforming growth factor beta 1 (TGF-β1) are anti-inflammatory cytokines.

Transcutaneous electrical nerve stimulation induces vasodilation in healthy controls but not in refractory angina patients.

Context: Transcutaneous electrical nerve stimulation (TENS) is an effective treatment option to relieve ischemic pain in refractory angina pectoris (RAP). In healthy persons, TENS enhances local blood flow, but the mechanism responsible for the anti-ischemic effect in RAP seems to be different.

Objective: The aim of the present investigation was to compare the difference in blood flow and vasodilatory response to TENS between angina patients and healthy controls and evaluate how vascular response in these groups is affected by amperage dosage above and below motor threshold levels.

Mild hypothermia markedly reduces ischemia related coronary t-PA release.

In experimentally induced myocardial ischemia, mild hypothermia (33-35 degrees C) has a robust cardioprotective effect. Tissue plasminogen activator (t-PA) is a profibrinolytic enzyme that is released from the vascular endothelial cells in response to ischemia and other injurious stimuli. t-PA has also been found to have proinflammatory properties that could contribute to reperfusion injury.

Suppression of endothelial t-PA expression by prolonged high laminar shear stress.

Primary hypertension is associated with an impaired capacity for acute release of endothelial tissue-type plasminogen activator (t-PA), which is an important local protective response to prevent thrombus extension. As hypertensive vascular remodeling potentially results in increased vascular wall shear stress, we investigated the impact of shear on regulation of t-PA. Cultured human endothelial cells were exposed to low (< or =1.

Heterogeneous glycosylation patterns of human PAI-1 may reveal its cellular origin.

The main inhibitor of intravascular fibrinolysis is plasminogen activator inhibitor 1 (PAI-1) which binds to and irreversibly inhibits tissue plasminogen activator (tPA). PAI-1 is present in blood, both in platelets and in plasma, and PAI-1 levels are associated with risk of atherothrombosis. Several tissues express PAI-1 but the source of plasma PAI-1 is not known.

Effects of IL-1beta and IL-6 on tissue-type plasminogen activator expression in vascular endothelial cells.

Introduction: The increased risk of thrombus formation in inflammatory conditions is generally considered to be due to the pro-coagulant effect of inflammatory cytokines. However, cytokines may also decrease the expression of the key fibrinolytic enzyme tissue-type plasminogen activator (t-PA) causing a reduced clearance of emerging intravascular thrombi. This study investigated the effects of the inflammatory cytokines interleukin (IL)-1beta and IL-6 on t-PA gene and protein expression, and elucidated by which signaling mechanisms the effects are mediated.

Left bundle branch block and cardiovascular morbidity and mortality in hypertensive patients with left ventricular hypertrophy: the Losartan Intervention For Endpoint Reduction in Hypertension study.

Background: Whether left bundle branch block is associated with cardiovascular events in hypertension with electrocardiographic left ventricular hypertrophy is unknown.

Methods: Hypertensive patients with electrocardiographic-left ventricular hypertrophy were randomized to losartan-based or atenolol-based treatment and followed for 4.8 years in the losartan intervention for endpoint reduction in hypertension study.

In-treatment resolution or absence of electrocardiographic left ventricular hypertrophy is associated with decreased incidence of new-onset diabetes mellitus in hypertensive patients: the Losartan Intervention for Endpoint Reduction in Hypertension (LIFE) Study.

Treatment of hypertensive patients with electrocardiographic left ventricular hypertrophy with losartan-based therapy is associated with lower incidence of diabetes mellitus and greater regression of hypertrophy than atenolol-based therapy. However, whether in-treatment resolution or continued absence of electrocardiographic hypertrophy is independently associated with decreased incidence of diabetes is unclear. Electrocardiographic hypertrophy was evaluated over time in 7998 hypertensive patients without diabetes at baseline in the Losartan Intervention For Endpoint reduction in hypertension (LIFE) study who were treated with losartan- or atenolol-based regimens and followed with serial electrocardiograms and blood pressure determinations.

Plasminogen activator inhibitor 1 expression in platelets is not influenced by the 4G/5G promoter polymorphism.

In the present study we investigated the influence of the 4G/5G promoter polymorphism of the PAI-1 gene on the levels of PAI-1 mRNA and protein in platelets. After a screening of healthy male subjects, thirty-eight subjects homozygote for either the 4G or 5G allele were investigated. mRNA levels were quantified by real-time PCR and PAI-1 antigen in platelets and plasma was analysed by ELISA.

Regression of electrocardiographic left ventricular hypertrophy is associated with less hospitalization for heart failure in hypertensive patients.

Background: Reduction of electrocardiographic left ventricular hypertrophy (LVH) has been associated with decreased cardiovascular death, stroke, myocardial infarction, and atrial fibrillation. However, whether reduction of electrocardiographic LVH is associated with decreased heart failure is unclear.

Objective: To examine the relation of reduction of electrocardiographic LVH to incident heart failure.