58 Clinical Trials for Various Conditions
The purpose of this study is to test the hypothesis that endothelin plays a role in the pathogenesis of supine hypertension in pure autonomic failure by increasing vascular resistance. To gauge its contribution to blood pressure regulation, pure autonomic failure and multiple system atrophy patients with supine hypertension will undergo a medication testing with the endothelin blocker, BQ123. We will compare the hemodynamic effects between PAF and MSA patients. Our primary endpoint will be the decrease in blood pressure during the administration of this compound.
The goal of this study is to answer the following questions: * What is the time course of the expected changes in endothelin levels during the first two weeks after injury and how does this relate to outcome? * What is the relation between endothelin levels (big ET-1 and ET-1) in plasma and cerebrospinal fluid and type of injury, from CT scans and GCS? * What is the relation between endothelin levels (big ET-1 and ET-1) in plasma and cerebrospinal fluid and outcome measurements like GOSE, ICP and CT scans? * What is the relation between neurohormones related to the neutral endopeptidase (NEP) (ANP, BNP and cGMP) in plasma and cerebrospinal fluid and type of injury, from CT scans and GCS? * What is the relation between endothelin levels (big ET-1 and ET-1) in plasma and cerebrospinal fluid and markers for apoptosis?
Previous studies have shown that insulin may stimulate the release of endothelin (ET) from endothelial cells. This mechanism may contribute to the adverse vascular effects determined by chronic hyperinsulinemia. The aim of this study will be to evaluate the effect of local hyperinsulinemia on ET activity in the forearm circulation. To this purpose, we will assess the forearm blood flow response to ET receptor antagonism in control conditions and during intraarterial infusion of insulin. We will also measure changes in plasma ET-1 levels in response to the different pharmacological stimuli.
Endothelin-1 (ET-1) is a powerful vasoconstricting peptide produced predominantly by vascular endothelial cells, that exerts its effect through the interaction with specific receptors, ETA and ETB, on the underlying smooth muscle cells. Previous studies in normal subjects have demonstrated an increase in forearm blood flow after ET-1 antagonism, suggesting a physiologic role of ET-1 in the regulation of basal vascular tone. However, whether ET-1-mediated tone is increased in hypertensive patients is unknown. The main purpose of this study will be to compare the forearm vascular responses to local infusion of ET-1 receptor antagonists between normotensive and hypertensive subjects in order to assess whether ET-1-mediated basal tone is increased in patients with hypertension. In addition, we propose to study the vascular responses to local ET-1 infusion to determine whether vascular smooth muscle sensitivity to this peptide is increased in hypertensive vessels. We will use both an ETA receptor antagonist, BQ-123, and an ETB receptor antagonist, BQ-788, in order to evaluate the relative contribution of the two receptor subtypes to the regulation of vascular tone. All drugs will be infused into the brachial artery and the responses of the forearm vasculature will be measured by means of strain gauge plethysmography. Because of the relative long-lasting effect of most of the substances to be infused, the study will be performed on two separate occasions.
Many patients with end-stage heart failure, a condition in which the heart fails to pump enough blood to support the body's other organs, are fortunate enough to receive a heart transplant. However, despite taking medicines aimed at blunting the immune system's response to the donor heart, some of them will develop transplant-related disease in the coronary arteries supplying their hearts. Fifty years after the first human-to-human heart transplant, this disorder-cardiac allograft vasculopathy (CAV)-remains a leading cause of long-term death and has been coined the 'Achilles' Heel' of heart transplantation. Indeed, a better understanding of how CAV occurs and improved therapies to prevent and/or slow its development are desperately needed to meaningfully impact patient outcomes. Endothelin-1 (ET-1) is a key molecular regulator of arterial health, and our prior data suggests that it is associated with accelerated CAV. In this particular study of recent heart transplant recipients, we are asking: Does ET-1 contribute to the coronary artery's capacity to dilate/constrict? To answer this question, during the cardiac catheterization at 1 year post-transplant (standard of care), we will measure blood levels of ET-1 and perform an invasive evaluation of coronary vasomotor function inn a consecutive subset of patients who will have received a 1-week course of the oral endothelin receptor antagonist (macitentan) prior this catheterization, which will allow us to test how much ET-1 contributes to coronary responsiveness. The findings from this study may provide the necessary foundation to study whether endothelin receptor antagonists are able to effectively reduce the rate of accelerated CAV.
This study aims to evaluate the comparative risk of dementia/Alzheimer's disease onset between patients treated with medications that target specific metabolic pathways and patients treated with alternative medications for the same indication.
The research aims of this proposal are: * Specific Aim 1: To test whether an increase in nitric oxide signaling can increase vasodilator responses in young Black individuals. * Specific Aim 2: To test whether a decrease in endothelin-1 signaling can increase vasodilator responses in young Black individuals.
The proposed study is designed to test the hypothesis that treatment of resveratrol for 12 weeks will improve both endothelin-B receptor (aim 1) and skeletal muscle mitochondrial function (aim 2) in people with type 1 diabetes.
The goal of the study is to examine the possible mechanisms of impaired cutaneous microvascular function through local heating along with administration of vasoconstrictors.
Elevated levels of ET-1 have been implicated in cardiovascular disease and some forms of hypertension. Due to the strong, positive correlation between obesity and hypertension, the present study will explore the contribution of adiposity in ETB receptor function and aim to elucidate if ETB receptor dysfunction is a major contributor to hypertension in obesity.
The primary goal of the study is to determine the safety and tolerability of ambrisentan. It is also expected that ambrisentan will improve blood flow in the lungs, decrease inflammation, and reduce pain in sickle cell patients. An additional goal is to evaluate the use of select biomarkers in evaluating sickle nephropathy.
Heart disease is the leading cause of death in the United States, accounting for one in every four deaths in 2010 and costing over $300 billion annually in health care, medication, and lost productivity. Heart failure (HF), a clinical syndrome that develops as a consequence of heart disease, is characterized by the worsening of symptoms, such as dyspnea and fatigue, upon exertion, collectively defined as "exercise intolerance". Surprisingly, exercise intolerance does not correlate with the degree of cardiac contractile (ventricular) dysfunction, suggesting that changes in the peripheral circulation may be to blame for exercise intolerance in this cohort. Though there are a host of factors that may contribute to this impairment, disease-related increases in circulating endothelin-1 (ET-1) may be a significant factor in the sequelae of exercise intolerance in HF. Thus, the overall purpose of this Small Projects in Rehabilitation Research (SPiRE) proposal is to explore the contribution of ET-1 to chronic vasoconstriction in HF patients, and to examine whether inhibition of this pathway could improve vasodilatory ability, and thus exercise tolerance, in Veterans with HF.
Our bodies respond differently to stress. Animal studies by the investigators have found that endothelin-1 plays a role in regulating blood pressure in response to stress. This study is an extension of the investigators previous animal work to evaluate the role of endothelin-1 during stress in humans.
Peripheral artery disease (PAD) is a major complication of atherosclerosis when blockages in the arteries to leg reduce blood flow and one of the resulting problems is termed intermittent claudication (IC). IC is leg pain with walking that is relieved with rest and IC is the most frequent clinical manifestation of PAD and it effects millions of Americans. The number of patients with, and the health care costs of, PAD will increase as the prevalence of PAD is associated with advancing age, diabetes, and smoking. Zibotentan (ZD4054) is an endothelin receptor A (ETA) blocker that undergone extensive human testing and has been shown to be safe in several patient population. There is ample evidence to suggest that an ETA blocker could improve blood flow to the legs in patients with PAD. In a study that will be funded by the National Institute of Health, the investigators will test the ability of this medication to allow better blood flow to the legs of patients with PAD. In patients with IC, the investigators will test the ability of ZD4054 to improve leg blood flow using a non-invasive imaging technique. In parallel the study will test for the ability of patients with leg pain to walk further and feel better.
The investigators hypothesize that nebivolol will reduce ET-1-mediated vasoconstrictor tone in adult humans with elevated blood pressure to a greater extent than either metoprolol or placebo.
Recent studies have shown beneficial effects of sildenafil in patients with single ventricle congenital heart disease. The purpose of this study is to determine whether Bosentan, a drug with similar effects, will have similar benefit in this patient population.
Aims: 1. Does inflammation contribute importantly to concurrent defects in vascular and metabolic dysfunction in human pre-diabetic obesity? 2. Are there benefits of anti-inflammatory treatment strategies in pre-diabetic obesity in the context of existing treatment with metformin? 3. Are there benefits of anti-inflammatory treatment strategies in pre-diabetic obesity in the context of existing treatment with lisinopril?
This study is an international, multi-center, randomized, double-blind, placebo-controlled study in subjects with PAH who are currently receiving approved therapy for their PAH (i.e., endothelin receptor antagonist and/or phosphodiesterase-5 inhibitor)or as a monotherapy treatment. Study visits will occur at 4 week intervals for 12 weeks with the key measure of efficacy being the 6-minute walk test. Study procedures include routine blood tests, medical history, physical exams, disease evaluation, and exercise tests. At the end of the first 12-weeks, the patient will be un-blinded. Patients will continue with another 12-Week open label portion with visits occuring at 4-week intervals. Patients who complete all assessments for 24-weeks will also be eligible to enter a 36 month open-label, extension phase study (FREEDOM - EXT).
The purpose of the study is is to determine the effect, on the lung circulation, of BQ-123, an investigational compound which is not approved by the FDA.
Pulmonary hypertension is a progressive and life threatening condition. It is characterized by severe remodeling of the pulmonary vessel wall, obstructive plexiform lesions, multi-focal thrombosis, and enhanced vasoconstriction. All of these characteristics contribute to increased pulmonary vascular resistance. Circulating endothelial microparticles (EMPs) play an integral role in the pathogenesis and perpetuation of pulmonary hypertension. Levels of EMPs are considered a reliable biological parameter of endothelial injury. We propose to assess the evolution of both circulating and pulmonary venous EMPs in patients with PH. Assessments will be made before and after initiation of Endothelin-1 (ET-1) Receptor blocker therapy, and correlated to their patterns with the changes in mean PAP, the 6 Minutes Walking Distance test, and circulating Endothelin-1 values. Measurements of the endothelial microparticle circulating levels (assessed by flow cytometry methods) will be made before, 1 month and 3 months after initiation of therapy.
The goal of this study is to examine the activation of markers of endothelial and cardiovascular dysfunctions, from women with high-risk pregnancies. Information from this study will hopefully provide enough information to determine a link between race, the advent of high risk pregnancies and cardiovascular markers. With this information it might be possible to intervene with approved pharmacological treatments.
Enthuse M0 is a large phase III clinical trial studying the efficacy of ZD4054 (Zibotentan) in hormone resistant prostate cancer (HRPC). This clinical trial will test if the Endothelin A Receptor Antagonist ZD4054 (Zibotentan) can improve progression-free survival and overall survival against a background of existing prostate cancer treatments. ZD4054 (Zibotentan) is a new type of agent, which is thought to slow tumour growth and spread by blocking Endothelin receptor activity. This trial will look at the effects of ZD4054 (Zibotentan) in hormone resistant prostate cancer (HRPC) patients who have had rising PSA after surgical or medical castration but have no evidence of metastases. All patients participating in this clinical trial will receive existing prostate cancer treatments in addition to trial therapy. Half the patients will receive ZD4054 (Zibotentan) , and half the patients will receive placebo in addition to standard prostate cancer therapy. By participating in this trial there is a 50% chance that patients will receive an agent that may slow the progression of the tumour. No patients will be deprived of standard prostate cancer therapy.
Enthuse M1C is a large phase III clinical trial studying the safety and efficacy of ZD4054 (Zibotentan) in combination with docetaxel (Taxotere) in patients with metastatic hormone resistant prostate cancer (HRPC). This clinical trial will test if the Endothelin A Receptor Antagonist ZD4054 (Zibotentan) can further improve survival compared with docetaxel alone. ZD4054 (Zibotentan) is a new type of agent, which is thought to slow tumour growth and spread by blocking Endothelin A receptor activity. This trial will look at the effects of ZD4054 (Zibotentan) in hormone resistant prostate cancer patients with bone metastases compared with docetaxel. All patients participating in this clinical trial will receive docetaxel chemotherapy, which is a commonly used chemotherapy to treat prostate cancer in addition to other existing prostate cancer therapies. Half the patients will receive ZD4054 (Zibotentan), and half the patients will receive placebo in addition to docetaxel and other prostate cancer therapy. By participating in this trial there is a 50% chance that patients will receive an agent that may further slow the progression of the tumour. No patients will be deprived of standard prostate cancer therapy.
This is a 2-part, open-label, single-arm, dose escalation study. Part I will define the Maximum Tolerated Dose (MTD) and optimal dose of SPI-1620 and evaluate its PK and PD properties. Once the MTD for SPI-1620 is identified, a second phase of the study will focus on dose escalation of docetaxel studied in groups of 3-6 patients. This part of the study will assess the safety and tolerability of increasing doses of docetaxel administered with the optimal dose of SPI 1620 defined in Part I.
Percutaneous coronary intervention (PCI) for acute coronary syndromes frequently fails to restore myocardial perfusion despite establishing epicardial vessel patency. Endothelin-1 (ET-1) is a potent vasoconstrictor and its expression is increased in atherosclerotic coronary arteries. Our hypothesis is that increased activity of the endogenous endothelin system contributes to microvascular dysfunction, and adjunctive therapy with an endothelin receptor antagonist will result in improved microvascular blood flow. Aims: The aims of the study are to assess in patients with non ST-elevation myocardial infarction, whether: 1) PCI causes an increase in coronary blood ET-1 level; 2) an endothelin receptor antagonist acutely improves coronary microvascular blood flow following PCI. Non-ST segment elevation myocardial infarction (NSTEMI) is one type of heart attack. It is defined as the development of heart muscle necrosis results from an acute interruption of blood supply to a part of the heart which is demonstrated by an elevation of cardiac markers Creatinine Kinase Isoenzyme Muscle/Brain Type (CK-MB) in the blood and the absence of ST-segment elevation in ECG (electrocardiography). ST-segment is a portion of ECG, its elevation indicates full thickness damage of heart muscle. Absence of ST-segment elevation in NSTEMI indicates partial thickness damage of heart muscle occurs. Therefore, NSTEMI is less severe type of heart attack compared to STEMI (ST-segment elevation myocardial infarction) in which full thickness damage of heart muscle occurs.
Enthuse M1 is a large phase III clinical trial studying the safety and efficacy of ZD4054 (Zibotentan) in patients with hormone resistant prostate cancer and bone metastases. * This clinical trial will test if the Endothelin A Receptor Antagonist ZD4054 (Zibotentan) can improve survival compared with placebo. * ZD4054(Zibotentan) is a new type of agent, which is thought to slow tumour growth and spread by blocking Endothelin A receptor activity. This trial will look at the effects of ZD4054 (Zibotentan) in hormone resistant prostate cancer patients with bone metastases. * All patients participating in this clinical trial will receive existing standard prostate cancer treatments in addition to trial therapy. * Half the patients will receive ZD4054 (Zibotentan), and half the patients will receive placebo in addition to standard prostate cancer therapy. By participating in this trial there is a 50% chance that patients will receive an agent that may slow the progression of the tumour. * No patients will be deprived of standard prostate cancer therapy.
There is growing evidence that a cause of glaucoma is linked to circulatory problems and poor auto-regulation of blood flow to the optic nerve. Pulmonary hypertension (PH)is a disease characterized by low oxygen levels in the blood and altered blood circulation. The decrease in oxygen delivery to the optic nerve could lead to the loss of nerve fiber layer(NFL)in the retina and the resulting visual field compromise. This situation is characteristic of glaucoma. The ability to identify NFL thinning early could lead to earlier diagnosis of glaucoma and more effective treatment to limit dysfunction from visual field loss. We hypothesize that the rate of structural damage to the NFL, a feature of glaucoma, is higher in patients with PH than expected in healthy populations lacking this disease.
This study was an international, multi-center, randomized, double-blind, placebo-controlled study in subjects with PAH who were currently receiving approved therapy for their PAH (i.e., endothelin receptor antagonist and/or phosphodiesterase-5 inhibitor). Study visits occurred at 4 week intervals for 16 weeks; the key measure of efficacy was the 6-minute walk test. Study procedures included routine blood tests, medical history, physical exams, disease evaluation, and exercise tests. One optional substudy was also a part of FREEDOM-C at select centers - a hemodynamic substudy with a right heart catheterization at Baseline and Week 16. Patients who completed all assessments for 16-weeks were also eligible to enter an open-label, extension phase study (FREEDOM - EXT).
The purpose of the study is to assess the importance of a substance called endothelin. Endothelin is produced by coronary arteries. This study examines this substance to determine whether it has an effect on controlling blood flow in coronary arteries. When these arteries release too much endothelin, the blood flow to the heart muscle is reduced and this may be important in heart conditions. This protocol examines an investigational drug called BQ-123 to see if it blocks the effect of endothelin. We assess the blood flow in the coronaries and evaluate the effects of BQ-123. It is anticipated that this endothelin blocker will open up coronary arteries and increase the blood flow to the heart.
This is a novel preliminary study of biomarkers of pathologic pre-operative pulmonary vascular development, elevated pre-operative Pulmonary Vascular Resistance Index (PVRi), and complications associated with decreased post-operative pulmonary blood flow in single ventricle patients undergoing superior cavo-pulmonary anastomosis (SCPA). The study will utilize a combined targeted and untargeted approach to both optimize translation of a promising existing biomarker and efficiently identify novel biomarkers and potential therapeutic targets in this population.