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57 active trials for Endothelial Dysfunction

Samples From Human Subjects to Facilitate Basic, Translational and Clinical Research

Background: This study is designed to provide samples to help us study the genes your blood cells are making as well as the proteins, sugars, fats, vitamins and other metabolites found in your blood or urine. Blood samples may also be collected to make special cells. These are called induced pluripotent stem cells or iPSCs. Pluripotent stem cells are cells that can be converted into any type of cell. Researchers want to study in the lab iPSCs that are derived from blood samples. Objective: To collect samples to help study genes, proteins, sugars, fats, vitamins, and other metabolites found in blood or urine. Eligibility: Healthy volunteers and patients ages 18 and older Design: First-time research study participants at NIH will have an initial visit for this study that should last no more than 1 hour. All other visits should last 20 30 minutes. Participants will undergo a limited history and physical exam. Participants may have routine blood and urine tests. If participants are giving a blood sample, they must have a hemoglobin level checked in the past 12 months to make sure it is safe for them to give a blood sample for research. Participants may have a venous blood collection. They may do this at several visits. They will lie on a recliner or couch or sit in a chair. A needle will be placed into a vein in the hand or arm, using sterile techniques. Blood will be withdrawn into multiple syringes or tubes. Participants may be asked to provide urine in an appropriate container...

Start: September 2017
Enhancing Parasympathetic Activity to Improve Endothelial Dysfunction, Vascular Oxidative Stress in African Americans

Specific Aim 1: To test the hypothesis that prolonged (3-month) treatment with galantamine inhibits NADPH IsoLG-protein adducts formation and improves markers of endothelial cell (EC) dysfunction in AAs. Aim 1a: The investigators will determine if galantamine inhibits NADPH IsoLG-protein adducts formation, superoxide production, and immune cell activation compared to placebo. For this purpose, the investigators will study peripheral blood mononuclear cell (PBMC), a critical source of systemic oxidative stress, collected from study participants. Aim 1b: The investigators will determine if galantamine reduces intracellular Iso-LGs, ICAM-1, and 3-nitrotyrosine, a marker of vascular oxidative stress, in ECs harvested from study participants. Specific Aim 2: To determine if prolonged (3-month) treatment with galantamine improves endothelial dysfunction as measured by vascular reactivity in AAs. The investigators will measure vascular reactivity in response to ischemia in two vascular beds: (a) in conduit arteries (brachial artery) using brachial artery diameter flow-mediated dilation (FMD), and (b) in the microvasculature (MBV) using contrast-enhanced ultrasonography in skeletal muscle. This proposal will study a novel mechanism that could alter the oxidative and immunogenic responses that contributes to endothelial dysfunction in AAs and will offer a potential pathway for the development of more effective therapies aimed at decreasing the progression of endothelial dysfunction to cardiovascular disease in this population.

Start: July 2021
Effects of Aronia Berries on Vascular Endothelial Function and the Gut Microbiota in Middle-Aged/Older Adults

Aging is the primary risk factor for cardiovascular disease (CVD) largely due to vascular endothelial dysfunction, a major initial step in the development of atherosclerosis. Endothelial dysfunction is characterized by impaired endothelium-dependent dilation and is primarily caused by reduced nitric oxide bioavailability secondary to oxidative stress and inflammation. Interventions that improve endothelial dysfunction are important for improving endothelial function and reducing CVD risk in this high-risk population. Aronia melanocarpa, commonly known as aronia berries or chokeberries, are rich in polyphenols such as anthocyanins, proanthocyanidins, and phenolic acids. These compounds, and derivatives resulting from gut microbial and phase II metabolism, have been shown to attenuate oxidative stress and inflammation, and to improve endothelial function. Aronia berries and other berries have been shown in numerous studies to have diverse cardiometabolic health effects including modulation of endothelial function, arterial stiffness, blood pressure, oxidative stress, and inflammation. In addition, berries, dietary fiber, polyphenols have been shown to exert positive effects on the gut microbiota, which may mediate improvements in cardiovascular health. Recently, we have demonstrated that modulation of the gut microbiota is associated with improvements in vascular dysfunction. The primary goal of the currently proposed research is to assess the efficacy and dose-dependent response of an aronia full spectrum dietary supplement to improve endothelial function in middle-aged/older men and postmenopausal women. A secondary goal is to determine whether aronia full spectrum modulation of the gut microbiota is associated with improvements in endothelial function. Other functional and biochemical measures of cardiovascular health, oxidative stress, inflammation, and polyphenol metabolism will be assessed.

Start: February 2019
Blueberries for Improving Vascular Endothelial Function in Postmenopausal Women With Elevated Blood Pressure

Postmenopausal women are at an increased risk of developing cardiovascular disease (CVD) largely due to accelerated aging-related modifications to vascular health following menopause. The vascular endothelium is responsible for producing chemicals that are essential for proper vasodilation and blood flow and therefore is involved in maintaining normal blood pressure. A major modification that occurs during aging and is accelerated during menopause is termed vascular endothelial dysfunction which is characterized by impaired endothelium-dependent dilation. This can lead to increased blood pressure, atherosclerosis, and increased risk of CVD and death. Nitric oxide (NO) is a chemical produced by the endothelium and is essential for normal endothelial function and cardiovascular health. Vascular endothelial dysfunction is primarily caused by reduced NO bioavailability secondary to excessive oxidative stress. Approximately 3/4 of postmenopausal women have elevated blood pressure or hypertension which further worsens endothelial function and increases CVD risk through increased oxidative stress and inflammation. Blueberries are rich in phytochemicals including anthocyanins, phenolic acids, and pterostilbene. These phytochemicals and their metabolites are known to attenuate oxidative stress and inflammation. The overall goal of the current study is to assess the efficacy of blueberries to improve vascular endothelial dysfunction in this high-risk population and to gain insight into underlying mechanisms. 58 postmenopausal women with elevated blood pressure and stage 1-HTN and vascular endothelial dysfunction at the screening visit will be asked to consume 22 grams freeze-dried blueberry powder or placebo powder per day for 12 weeks. Vascular endothelial function will be assessed at baseline and 12 weeks. Measurements indicative of vascular nitric oxide production, oxidative stress, inflammation, cardiometabolic health, cognitive function, and blueberry phytochemical metabolism will be measured at baseline and 12 weeks. Blood pressure will be assessed at baseline and 4, 8, and 12 weeks.

Start: December 2017
Novel Time-efficient Inspiratory Muscle Strength Training for Lowering Systolic Blood Pressure

Above-normal systolic blood pressure (SBP), defined as SBP >/= 120 mmHg, is the major modifiable risk factor for cardiovascular disease, stroke, cognitive decline/dementia, and other chronic health problems. Despite the availability of treatments to lower SBP, over 75 percent of adults with above-normal SBP fail to control BP, which has led to a nearly 50 percent increase in the number of deaths attributable to BP over the past decade. Therefore, above-normal SBP is a major public health burden. Greater than 65 percent of adults 50 years of age and older have above-normal SBP. The number of adults age 50 years and older is rapidly increasing, predicting a continued increase in above-normal SBP driven morbidity and mortality in the absence of effective treatment strategies. This makes developing novel SBP-lowering therapies an urgent biomedical research priority. Increasing SBP is closely linked to vascular dysfunction, observable as impaired endothelial function, increased large-elastic artery stiffness, and impaired cerebrovascular function. Declines in these functions play a large role in the increased risk of chronic disease associated with above-normal SBP. The primary mechanism responsible for SBP-induced vascular dysfunction is thought to be oxidative stress-associated inhibition of nitric oxide bioavailability. Therefore, to have the largest biomedical impact, new SBP-lowering therapies should also improve vascular function by decreasing oxidative stress. Healthy lifestyle practices, such as conventional aerobic exercise, maintaining a healthy diet, or reducing sodium intake, are all first-line strategies to lower SBP. Importantly, these lifestyle practices also improve vascular function, in large part by reducing oxidative stress. However, adherence to healthy lifestyle practices is poor, with adherence to guidelines generally between 20 to 40 percent in adult Americans. The greatest reported barrier to meeting healthy lifestyle guidelines is lack of time. Therefore, time-efficient interventions have great promise for promoting adherence, reducing SBP, and improving other physiological functions. High-resistance inspiratory muscle strength training (IMST) is a time-efficient (5 minutes per session) lifestyle intervention consisting of 30 inspiratory maneuvers performed against a high resistance. Preliminary data suggest 6-weeks of IMST performed 6 days/week reduces SBP by 9 mmHg in adults with above-normal SBP (i.e., greater than 120 mmHg) at baseline. Importantly, this reduction in SBP is equal to or greater than the reduction in blood pressure typically achieved with time- and effort-intensive healthy lifestyle strategies like conventional aerobic exercise. However, these results need to be confirmed in an appropriately powered clinical trial with a longer, guideline-based treatment duration. Furthermore, the influence of IMST on functions impaired by above-normal SBP (endothelial, cerebrovascular, cognitive) needs to be determined, as do the mechanisms through which IMST exerts beneficial effects. Accordingly, we will conduct a randomized, blinded, sham-controlled, parallel group design clinical trial to assess the efficacy of 3-months of IMST (75 percent maximal inspiratory pressure) vs. brisk walking (40-60% heart rate reserve; an established healthy lifestyle strategy) for lowering SBP and improving endothelial, cerebrovascular, and cognitive function in adults age 50 years and older with above-normal SBP. I hypothesize IMST will lower SBP and improve endothelial function by decreasing oxidative stress and increasing nitric oxide bioavailability. I also hypothesize IMST will improve cerebrovascular and cognitive function, and that these improvements will be related to reductions in SBP and improvements in endothelial function. I also expect adherence to the intervention to be excellent (over 80 percent of all training sessions completed at the appropriate intensity). To test my hypothesis, I will recruit 102 adults age 50 years and older who have SBP >/= 120 mmHg. Subjects will undergo baseline testing for casual (resting) SBP, 24-hour ambulatory SBP, endothelial function, arterial stiffness, cognitive function, and cerebrovascular function. Innovative mechanistic probes including pharmaco-dissection with vitamin C, analysis of biopsied endothelial cells, and high-throughput metabolomics, will be performed to assess oxidative stress and nitric oxide bioavailability at baseline. After baseline testing, subjects will be randomized to perform either 3-months of high-resistance IMST or brisk walking. Subjects will train 6 days/week with one training session supervised in the laboratory and the other 5 performed unsupervised at home. Following 3 months of training, subjects will redo all the tests that were done during baseline testing to assess training-induced changes in SBP, physiological functions, and underlying mechanisms.

Start: May 2021
Immune Cells Phenotypes During COVID-19

The ongoing pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) has infected more than one hundred twenty million peoples worldwide one year after its onset with a case-fatality rate of almost 2%. The disease due to the coronavirus 2019 (i.e., COVID-19) is associated with a wide range of clinical symptoms. As the primary site of viral invasion is the upper respiratory airways, lung infection is the most common complication. Most infected patients are asymptomatic or experience mild or moderate form of the disease (80 %). A lower proportion (15%) develop severe pneumonia with variable level of hypoxia that may required hospitalization for oxygen therapy. In the most severe cases (5%), patients evolve towards critical illness with organ failure such as the acute respiratory distress syndrome (ARDS). At this stage, invasive mechanical ventilation is required in almost 70 % and the hospital mortality rises to 37 %. Immune cells are key players during SARS CoV-2 infection and several alterations have been reported including lymphocytes (T, B and NK) and monocytes depletion, and cells exhaustion. Such alterations were much more pronounced in patients with the most severe form of the disease. Beside, a dysregulated proinflammatory response has also been pointed out as a potential mechanism of lung damage. Finally, COVID-19 is associated with an unexpectedly high incidence of thrombosis which probably results from the viral invasion of endothelial cells. The investigators aim to explore prospectively the alterations of innate and adaptive immune cells during both the acute and the recovery phase of SARS CoV-2 pneumonia. Flow and Spectral cytometry will be used to perform deep subset profiling focusing on T, B, NK, NKT, gamma-gelta T, monocytes and dendritic cells. Each specific cell type will be further characterized using markers of activation/inhibition, maturation/differenciation and senescence as well as chemokines receptors. T-cell memory specificity will be explore using specific SARS CoV-2 pentamer. Platelet activation and circulating microparticles will be explore using flow cytometry. Serum SARS CoV-2 antibodies (IgA, IgM, IgG), serum cytokines, and serum biomarkers of alveolar epithelial and endothelial cells will be analyze using ELISA and correlate with the severity of the disease.

Start: March 2020
Intravenous Imatinib in Mechanically Ventilated COVID-19 Patients

The SARS-CoV2 pandemic and resulting COVID-19 infection has led to a large increase in the number of patients with acute respiratory distress syndrome (ARDS). ARDS is a severe, life-threatening medical condition characterised by inflammation and fluid in the lungs. There is no proven therapy to reduce fluid leak, also known as pulmonary oedema, in ARDS. However, recent studies have discovered that imatinib strengthens the cell barrier and prevents fluid leak in the lungs in inflammatory conditions, while leaving the immune response intact. The investigators hypothesize that imatinib limits pulmonary oedema observed in ARDS due to COVID-19, and may thus help to reverse hypoxemic respiratory failure and to hasten recovery. The hypothesis will be tested by conducting a randomised, double-blind, parallel-group, placebo-controlled multi-centre clinical study of intravenous imatinib in 90 mechanically-ventilated, adult subjects with COVID-19-related ARDS. Study participants will receive the study drug (imatinib or placebo) twice daily for a period of 7 days. The effect of the intervention will be tested by measuring extravascular lung water (i.e. pulmonary oedema) difference between day 1 and day 4, using a PiCCO catheter (= pulse contour cardiac monitoring device). Other measurements will include regular blood tests to investigate the safety and the pharmacokinetic properties of imatinib, as well as biomarkers of inflammation and cellular dysfunction. Furthermore, parameters of ventilation and morbidity and mortality will be recorded as secondary outcome measures.

Start: March 2021
Effect of Berberine Hydrochloride on Blood Pressure and Vascular Endothelial Function in Patients With Hypertension

Hypertension is a progressive cardiovascular syndrome caused by multiple causes, which can lead to changes in the function and structure of the heart and blood vessels. It is the leading risk factor of cardiovascular disease. Berberine (BBR) hydrochloride is an isoquinoline alkaloid (chemical formula: C20H18NO4) extracted from traditional Chinese herb Coptis chinensis. It has been widely used to treat diarrhea and enteritis for hundreds of years in China. BBR has extremely high clinical application value. It is an over-the-counter drug with low price, good safety and few adverse reactions in China. We found that Berberine (BBR) hydrochloride tablets have a hypotensive effect in clinical practice. However, there are few clinical studies on the treatment of hypertensive patients with BBR tablets. In addition, the clinical dosage of BBR tablets is not uniform, and its molecular mechanism is still unclear. In order to further evaluate the clinical efficacy of BBR in reducing blood pressure and improving vascular endothelial injury, we carried out this clinical trial of drug intervention for hypertensive population. After signed the informed consent, the subjects are assigned to the lifestyle intervention group (CON) and berberine hydrochloride group (BBR). The berberine hydrochloride group (BBR) take berberine hydrochloride tablets (0.4g, 3 times/day, 3 months) . We will follow up blood pressure and vascular endothelial function in 1 month and 3 months after taking the medicine.

Start: October 2020